ALBERT

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This work reported the structure and optical investigations of CdS〈sub〉1−〈em〉x〈/em〉〈/sub〉Mn〈sub〉〈em〉x〈/em〉〈/sub〉 (〈em〉x〈/em〉 = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10) thin films. The thin films of CdS〈sub〉1−〈em〉x〈/em〉〈/sub〉Mn〈sub〉〈em〉x〈/em〉〈/sub〉 with different compositions were synthesized using electron beam evaporation method under high vacuum conditions at room temperature. X-ray diffraction (XRD) analyses revealed the polycrystalline nature of the deposited films. The observed diffraction peaks were well fitted with a hexagonal crystal structure. In addition, the intensity of XRD peaks decreased by increasing the Mn concentration indicating a monotonical deterioration in the crystalline quality by the doping. The (101) plane is the preferential orientation for the crystal growth of the studied films. The film thickness as well as a refractive index were calculated by Swanepoel’s method. The direct and indirect electronic transitions were found to be responsible for the high absorption process in the studied films. Furthermore, both direct and indirect bandgaps decreased with increasing the Mn content. Other optical parameters such as optical conductivity, real and imaginary parts of dielectric constant, dispersion energy, and dissipation factor were determined and showed a strong dependence on the Mn content. These findings were discussed in terms of the localized states.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉To analyze the influence of processing conditions on the melt pool geometry and dilution ratio of the Ni-based alloy during laser cladding, a finite element model of heat transfer and fluid flow with multi-physical parameters was established. This model is used to simulate the temperature and velocity fields of melt pool. Thermodynamic processes such as phase transition, Marangoni convection and buoyancy were considered in this model. Adding materials in real time was considered by introducing powder feeding rate. The relative energy–mass ratio (REMR) was introduced to simplify process analysis, and the effects of different processing parameters on the dilution rate and on the melt pool geometry were explored through the established model. The results show that dilution ratio and REMR are linearly related within a certain range. In addition, due to the fluid flow, the boundary at bottom of melt pool changes gradually from shallow arc shape to wave shape, and finally to deep arc shape with increased REMR.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The 〈em〉Streptomyces〈/em〉 sp. strain AV05 isolated from an organic amendment was found to impact both growth and fumonisin production of 〈em〉Fusarium verticillioides〈/em〉 during in vitro direct confrontation. In order to investigate the interactions between the 〈em〉Streptomyces〈/em〉 sp. strain AV05 and 〈em〉F〈/em〉. 〈em〉verticillioides〈/em〉, a metabolomic approach was used. The study of the endometabolomes of the microorganisms was carried out in two different conditions: the microorganisms were cultivated alone or in confrontation. The aim of this study was to examine the modifications of the endometabolome of 〈em〉F〈/em〉. 〈em〉verticillioides〈/em〉 in confrontation with the 〈em〉Streptomyces〈/em〉 strain. The metabolites involved in these modifications were identified using 2D NMR. Many metabolites were found to be overproduced in confrontation assays with the 〈em〉Streptomyces〈/em〉 strain, notably 16 proteinogenic amino acids, inosine, and uridine. This suggested that fungal metabolic pathways such as protein synthesis have been affected due to interaction. Thus, metabolomic studies, as well as proteomics or transcriptomics, are useful for deciphering the mechanisms of interactions between biological control agents and mycotoxigenic fungi. This comprehension is one of the key elements of the improvement of the selection and use of antagonistic agents.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Mastitis in dairy cows is generally considered to be the most expensive disease for dairy farmers worldwide. The overuse of antibiotics is a major problem in the treatment of bovine mastitis, and bacteriophage therapy is expected to provide an alternative treatment. The primary aim of this study was to evaluate the efficacy of a phage cocktail against mastitis in a mouse model. First, a 〈em〉Staphylococcus aureus〈/em〉 strain was isolated from milk samples taken from mastitis cows from dairy farms in Xinjiang, China, and it was designated as Sau-XJ-21. Next, two phages (designated as vBSM-A1 and vBSP-A2) with strong lytic activity against Sau-XJ-21 were isolated from mixed sewage samples collected from three cattle farms in Xinjiang. Phages vBSM-A1 and vBSP-A2 were identified as members of the Myoviridae and Podoviridae families, respectively. The two phages exhibited a wide range of hosts, especially phage vBSM-A1. To evaluate the effectiveness of the two phages in the treatment against mastitis, female lactating mice were used 10–14 days after giving births. The mice were divided into six groups; one group was kept as healthy control, while the remaining five groups were inoculated with the isolated 〈em〉S. aureus〈/em〉 strain to induce mastitis. Four hours after bacterial inoculation, mice in these groups were injected with 25 μL phosphate buffer saline (negative control), ceftiofur sodium (positive control), or phage, either individually or as a cocktail. The mice were sacrificed 20 h later, and the mammary glands were removed and subjected to further analysis, including the quantitation of colony-forming units (CFU), plaque-forming units (PFU), and gross macroscopic as well as histopathology observation. Mice with induced mastitis exhibited significantly improved mastitic pathology and decreased bacterial counts after they had been given phage treatments, with the phage cocktail being more superior than either phage alone. Furthermore, the cocktail treatment also maintained the highest intramammary phage titer without spreading systemically. The effectiveness of the phage cocktail was comparable to that produced by ceftiofur sodium〈em〉.〈/em〉 According to the data obtained for the mouse model of mastitis, phage therapy could be considered as an innovative alternative to antibiotics for the treatment of bovine mastitis.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Energy absorption buildup factor (EABF) and exposure buildup factor (EBF) of bismuth borate glass systems in structure (75–〈em〉x〈/em〉)〈span〉 〈span〉\(\text {B}_2\text {O}_3\)〈/span〉 〈/span〉–〈span〉 〈span〉\(x\text {Bi}_2\text {O}_3\)〈/span〉 〈/span〉–〈span〉 〈span〉\(10\text {Na}_2\text {O}\)〈/span〉 〈/span〉–〈span〉 〈span〉\(10\text {CaO}\)〈/span〉 〈/span〉–〈span〉 〈span〉\(5\text {Al}_2\text {O}_3\)〈/span〉 〈/span〉 (〈span〉 〈span〉\(0\le {x} \le 25 \text { mol}\%\)〈/span〉 〈/span〉) have been investigated for photon energy region between 0.015 and 15 MeV and for penetration depths of 1–40 mfp. Five parameters (G–P) fitting method has been carried out for computations procedure. The calculated values of EABF and EBF have been observed to be dependent on photon energy, penetration depths and on the concentration of 〈span〉 〈span〉\(\text {Bi}_2\text {O}_3\)〈/span〉 〈/span〉 mol% in the glass sample. It has been found that BOB25 glass offers better gamma-ray shielding than other samples. In addition, the values of EABF and EBF have been compared and significant differences up to 〈span〉 〈span〉\(8\%\)〈/span〉 〈/span〉 have been noted in intermediate energy region.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Lower respiratory tract infection due to 〈em〉Pseudomonas aeruginosa〈/em〉 has become increasingly challenging, resulting in a worse morbidity and mortality. Airway remodeling is a common phenomenon in this process, to which epithelial-mesenchymal transition (EMT) may contribute as an important promoter. Previous studies showed that epithelium-specific integrin αvβ6–mediated EMT was involved in pulmonary fibrosis via transforming growth factor-β1 (TGF-β1) signaling, but whether integrin αvβ6 plays a role in the 〈em〉P. aeruginosa〈/em〉–associated airway remodeling remains unknown. BEAS-2B cells were incubated with lipopolysaccharide (LPS) from 〈em〉P. aeruginosa〈/em〉 in the presence or the absence of integrin αvβ6–blocking antibodies. Morphologic changes were observed by an inverted microscopy. The EMT markers were detected using Western blotting and immunofluorescence. The activation of TGF-β1-Smad2/3 signaling pathway was assessed. Furthermore, matrix metalloproteinase (MMP)-2 and -9 in the medium were measured using ELISA. 〈em〉P. aeruginosa〈/em〉’s LPS decreased the expression of the epithelial marker E-cadherin and promoted the mesenchymal markers, vimentin and α-smooth muscle actin in BEAS-2B cells. The expression of integrin αvβ6 was significantly increased during EMT process. Blocking integrin αvβ6 could attenuate 〈em〉P. aeruginosa〈/em〉’s LPS-induced EMT markers’ expression via TGF-β1-Smad2/3 signaling pathway. Furthermore, blocking integrin αvβ6 could prevent morphologic changes and oversecretion of MMP-2 and -9. Integrin αvβ6 mediates epithelial-mesenchymal transition in human bronchial epithelial cells induced by lipopolysaccharides of 〈em〉P. aeruginosa〈/em〉 via TGF-β1-Smad2/3 signaling pathway and might be a promising therapeutic target for 〈em〉P. aeruginosa〈/em〉–associated airway remodeling.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In the silicon dicing processes, the laser induced thermal-crack propagation (LITP) has been reported about its superiority over traditional dicing methods in aspect of crack surface quality and mechanical properties. However, this process may cause deviation of its propagation path especially under the condition of asymmetric linear cutting. Aiming to solve the path-deviation problem, a method of pre-crack on the surface of the silicon wafer has been proposed. A mathematical model which consists absorption of laser, heat transfer, generation of thermal stress, and crack initiation and propagation, has been established. Numerical simulation in the LITP of silicon wafer with respect to two pre-crack modes: pre-crack on the end and pre-crack on the surface were conducted to study the high-quality crack propagation mechanism. Unbiased crack propagation was found in the simulation of pre-crack on the surface process and the mechanism of it was revealed through the analysis of the tensile stress distribution. It was found that the three-dimensional shape of the tensile stress at the front of the crack tip would result in an uncertain propagation in conventional LITP of pre-crack on the end. Conversely, the slice shape of the tensile stress would induce a certain propagation direction that was along the plane of the pre-crack in the simulation of pre-crack on the surface. The experimental results verified the unbiased propagation mode and showed good crack surface quality.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Typically, low cost as well as stability factors of the organo-metal halide perovskite solar cells based on inorganic hole transport layers (HTLs) have been the focus of intense research over the past few years. Accordingly, the power conversion efficiencies have rapidly been improved to ~ 20% with high stabilities. Therefore, this review covers the major advances of inorganic HTLs in perovskite solar cells that have contributed to the recent efficiencies and stabilities, including the evolution of device architecture, the development of hole transport material deposition processes, synthesis, morphology and the interface properties between inorganic HTLs and perovskite layers. Eventually, the challenges and future directions for inorganic HTLs-based perovskite solar cells are also discussed.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Spinel ferrites at nanoscale showed quite different properties rather than the bulk counterpart. Among all the ferrites, ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 compound is chemically stable and showed very good properties at room temperature. In this investigation, we reported the synthesis and characterization of ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 single-phase crystals of diameter 11 nm by solvothermal reflux method. Temperature-dependent dielectric constant, dielectric loss, and ac-electrical conductivity of the pellet were measured up to 450 °C under different alternating electric field frequencies from 1 kHz to 1 MHz. The obtained data revealed interfacial or space charge polarization mechanism. Furthermore, the sample showed superparamagnetic nature at room temperature. In addition, the magnetic hyperthermia value and specific heat generation rate (SHGR) of 128.76 J s〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉 for ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 compound at 1 mg mL〈sup〉−1〈/sup〉 concentration were evaluated. The data were interpreted by spin-relaxation mechanism. ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 nanoparticles showed good photocatalytic activity under UV light irradiation. The data were interpreted by electron–hole pair and radical formation and degradation of Rhodamine B dye.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this work, homogeneous PVC/MWCNT nano-composite films with different concentrations of MWCNTs were prepared. The MWCNTs were treated with plasma to improve their compatibility in the PVC matrix. The prepared films are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–visible spectroscopy (UV–Vis.) and thermogravimetric analysis (TGA). The XRD, XPS, FTIR and Raman results suggest that the plasma-functionalized MWCNTs are well dispersed and interacted with the PVC. XPS results show that the stoichiometric contents of C and O groups relatively increased with the increasing percentage of MWCNTs in the nano-composite, meanwhile, Cl group decreased. The optical band gap 〈span〉 〈span〉\(E_{\mathrm{g}}\)〈/span〉 〈/span〉 of PVC–MWCNTs decreases with the increasing MWCNTs percentage in the nano-composite. Increasing the percentage of MWCNTs in the PVC nano-composite improves thermal stability, dielectric constant and AC conductivity.〈/p〉

Beschreibung: 〈p〉In the originally published version of this article the acknowledgement was missing.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Corn starch and citric acid, two low-cost and abundant materials, were used for establishing a novel screen printable hydrogel for printed electronics applications. Corn starch was modified with citric acid by melt-blending; the so obtained thermoplastic starch was ground to powder and added to a water–starch suspension. Ultrasonication was used to prepare hydrogels of different citric acid concentrations. The most promising hydrogel contained 10% citric acid by weight, provided an ionic conductivity of (2.30 ± 0.07) mS cm〈sup〉−1〈/sup〉 and appropriate rheological properties for screen and stencil printing. The hydrogel shows superb printability and prolonged stability against degradation. The corn starch hydrogel was used as printable gel polymer electrolyte in fully printed supercapacitors. The specific capacitance of the printed supercapacitor reached 54 F g〈sup〉−1〈/sup〉. The printable hydrogel-polymer electrolyte is easy to produce without in-depth chemical knowledge, is based on widely used and non-toxic materials, and may be used as a functional layer in other printed electronics applications such as printed batteries.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, we report the fabrication of a high-sensitivity strain sensor fabricated using graphene platelets (GnPs) and multi-walled carbon nanotubes (MWCNTs) for monitoring joint-bending movement. The optimized ultrasonic time and the ball mill-mixing process make the GnPs disperse evenly in the MWCNTs. The strain sensor made up of the GnP/MWCNT mixture (30 wt% GnPs loading) is fabricated by a spray-method and its conductivity is up to 10〈sup〉4〈/sup〉 S/m. The as-prepared GnP/MWCNT sensor exhibits relatively high tensile strength of 5.4 MPa, sensing range of 7.5%, gauge factor of 181.36, linearity of 99.545%, and great bending reproducibility over 5000 cycles. These remarkable features endow our sensing devices to monitor joint bending in human health monitoring, e.g., elbow, finger and wrist bending. The results demonstrate that our flexible GnP/MWCNT sensor shows promising applications prospects in smart wearable device monitoring human health.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The present study is concerned with the synthesis and characterization of rare-earth-doped SrM (Sr〈sub〉1-〈em〉x〈/em〉〈/sub〉RE〈sub〉〈em〉x〈/em〉〈/sub〉Fe〈sub〉12〈/sub〉O〈sub〉19〈/sub〉) hexaferrites (RE = La, Ce and Tb; 〈em〉x〈/em〉 = 0, and 0.1). The hexaferrite precursor powders were prepared by high-energy ball-milling and sol–gel auto-combustion methods, and the powders were sintered at temperatures ≥ 900 °C. The effects of RE substitution and synthesis route on the structural and magnetic properties of SrM hexaferrites were investigated by X-ray diffraction, scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). Single SrM phase was obtained in the sample with 〈em〉x〈/em〉 = 0, and the sample with La substitution was prepared by ball-milling method. The rest of the samples, however, contained small amounts of minor phases of rare-earth oxides and α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 in addition to the major SrM phase. SEM imaging revealed significant decrease in particle size with RE substitution. Also, VSM measurements revealed small decrease in the saturation magnetization, and a significant increase in the coercivity with RE substitution. Comparable saturation magnetization was observed for the samples prepared by sol–gel method, whereas the coercivity increased significantly. The coercivity of samples prepared by sol–gel method exhibited a large increase with the decrease in sintering temperature, reaching ~ 6.2 kOe for the samples with Ce- and Tb-substituted samples sintered at 900 °C. The relatively high remnant magnetization (~ 30–35 emu/g) and high coercivity make these materials important candidates for permanent magnet applications.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Poly (acrylonitrile) (PAN), acetylene black (AB) and graphene oxide (GO), as conductive constituents, were mixed with sulfur by solution-processing technique using dimethyl sulfoxide as a solvent. The physical properties of the as prepared composites were characterized by X-ray diffraction, Raman and scanning electron microscope analysis. The electrochemical property of S/GO composite material exhibits better cyclical stability. The first-cycle capacity obtained by S/GO composite was 937 mAh g〈sup〉−1〈/sup〉 at 0.1 C with coulombic efficiency of 98% and good cycle ability around 813 mAh g〈sup〉−1〈/sup〉 discharge capacity at the 50th cycle which is higher than of S/PAN and S/AB composite.〈/p〉 〈span〉 〈h3〉Graphic abstract〈/h3〉 〈p〉 〈span〉 〈span〉 〈img alt="" src="https://static-content.springer.com/image/MediaObjects/339_2019_2758_Figa_HTML.png"〉 〈/span〉 〈/span〉 〈/p〉 〈/span〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Organic semiconductor charge transport layers are important constituents of perovskite-based solar cells. To assess the suitability of potential solvents for the deposition of the charge transport layers on perovskite surfaces, the effect of solvent exposure on the properties of methyl ammonium lead mixed halide CH〈sub〉3〈/sub〉NH〈sub〉3〈/sub〉PbI〈sub〉3–〈em〉x〈/em〉〈/sub〉Cl〈sub〉〈em〉x〈/em〉〈/sub〉 films is investigated by grazing incidence X-ray diffraction, atomic force microscopy, ultraviolet–visible absorption spectroscopy, and photoelectron spectroscopy. While exposure to dimethylformamide (DMF) and water instantly dissolves the perovskite film, exposure to chlorobenzene (CB) and chloroform (CF) does not detectably affect the perovskite bulk properties. However, the electronic properties of the perovskite surface are substantially modified by the solvent exposure, resulting in an increased work function and less n-type appearance.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Thin films of copper zinc tin sulfide (CZTS) have been synthesized on glass substrates at various thickness layers by change in number of layer from 3, 5 and 7 layers using sol–gel spin coating deposition technique. SEM photos were demonstrated for different thickness layer at constant temperature 280 °C. According the EDX analysis thin films exhibit nearly stoichiometry with 1.1 and (0.5–0.8) atomic ratio Cu/(Zn + Sn) and Cu/Zn, respectively. XRD pattern of the prepared CZTS films Show that the films have relatively high intensity peaks at 28.5° for 3 layer and 29.8° for 5 layers of 2〈em〉θ〈/em〉 value corresponding to (112), (220) and (312) phase, respectively. As the thickness layer of the synthesized CZTS films increases to 7 thickness layer, the film structure tends to be amorphous at the same temperature 280 °C, so the films were annealed to temperature 360 °C and 400 °C for a better crystallization state. The optical band gab is found in the range 1.5–1.8 eV and observed to decrease with thickness layer increasing. Additionally, the effect of the annealing temperature on the morphology and the energy gap for a film of 7 layer thicknesses at various temperatures from 280 to 400 °C was performed.〈/p〉

Beschreibung: 〈span〉 〈h3〉Abstract〈/h3〉 〈p〉Al–Co–Cr–Fe high-entropy alloy coatings were laser additively produced on aluminum substrate under different laser fluences (17.0–21.2 J/mm〈sup〉2〈/sup〉). The resultant coatings consisted of a mixture of high-entropy and intermetallic phases, which resulted in marked improvement in hardness (~ 275–500 HV) as compared to the aluminum substrate (~ 30 HV). Coating corresponding to higher laser fluences showed lower corrosion currents (〈em〉I〈/em〉〈sub〉corr〈/sub〉 ~ 3.6 × 10〈sup〉−4〈/sup〉 mA/cm〈sup〉2〈/sup〉) and higher linear polarization resistance (LPR) of ~ 14–16 kΩ/cm〈sup〉2〈/sup〉 as compared to the aluminum substrate (〈em〉I〈/em〉〈sub〉corr〈/sub〉 ~ 7×10〈sup〉−4〈/sup〉 mA/cm〈sup〉2〈/sup〉) and ~ 11 kΩ/cm〈sup〉2〈/sup〉 in 0.6 M NaCl solution. The behavior of surface properties was analyzed in relation to the variation in fraction of HEA and intermetallic phases within the coatings resulting due to increased content of Al from the Al substrate with an increase in the laser fluence. The coating consisting of optimal amount of HEA and intermetallic phases showed a tenfold decrease wear volume loss (0.01 mm〈sup〉3〈/sup〉) as compared to Al substrate showing 0.11 mm〈sup〉3〈/sup〉.〈/p〉 〈/span〉 〈span〉 〈h3〉Graphical abstract〈/h3〉 〈p〉 〈span〉 〈span〉 〈img alt="" src="https://static-content.springer.com/image/MediaObjects/339_2019_2573_Figa_HTML.png"〉 〈/span〉 〈/span〉 〈/p〉 〈/span〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Ferritin is an iron storage protein found in living organisms. It is an antiferromagnetic nanoparticle system consisting of an inorganic core surrounded by a protein shell. Ferritin is characterized by X-ray diffractometer, transmission electron microscope, atomic absorption spectrometer and thermogravimetric analyzer. We find that the ferritin core is poorly crystalline, 8 nm in size and consists of 10 wt% iron. It is believed that cores of ferritin consist of single-phase inorganic mineral ferrihydrite. Recently, we have shown that ferrihydrite decomposes directly to 〈span〉 〈span〉\(\alpha\)〈/span〉 〈/span〉-〈span〉 〈span〉\(\hbox {Fe}_{{2}}\hbox {O}_{3}\)〈/span〉 〈/span〉 on heating in air at 440 〈span〉 〈span〉\(^{\circ }\)〈/span〉 〈/span〉C. In the present work, we show that ferritin cores gradually decompose to a mixture of 〈span〉 〈span〉\(\gamma\)〈/span〉 〈/span〉-〈span〉 〈span〉\(\hbox {Fe}_{{2}}\hbox {O}_{{3}}\)〈/span〉 〈/span〉 and 〈span〉 〈span〉\(\alpha\)〈/span〉 〈/span〉-〈span〉 〈span〉\(\hbox {Fe}_{{2}}\hbox {O}_{{3}}\)〈/span〉 〈/span〉 on heating in air. This mixture finally stabilizes to 〈span〉 〈span〉\(\alpha\)〈/span〉 〈/span〉-〈span〉 〈span〉\(\hbox {Fe}_{{2}}\hbox {O}_{{3}}\)〈/span〉 〈/span〉 on further heating. The magnetic behaviour of final sample is also studied. This work confirms that the ferritin cores contain more than one phase.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We have studied the thin films of P3HT:PCBM and P3HT:ITIC blends as a prospective active layer for Organic Solar Cells by absorption, photoluminescence, and short-circuit current density–voltage characteristics. The potential estimation of structural changes in such photovoltaic devices is shown by employing the variations in absorption and photoluminescence spectra. The comparative analysis of key features of the absorption and photoluminescence spectra can be used as an indicator of their structural and photophysical properties.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉β-Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanowire (NW) was fabricated on a Si-substrate using glancing angle deposition (GLAD) technique. To study the structural, morphological, and optical properties of the as-deposited β-Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NW, thermal annealing was done at different temperatures ranging from 600 to 1000 °C and the corresponding results were analyzed. XRD analysis shows an increase in crystallinity of the as-deposited sample upon annealing. The average crystallite size was found to be increased from 13.72 to 20.19 nm after annealing at 900 °C. Annealed β-Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NW contains more concentration of oxygen due to absorption of O〈sub〉2〈/sub〉 molecules. The lattice strain and dislocation density of the as-deposited β-Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NW were found to reduce significantly after thermal annealing. The FEG-SEM image confirms the growth of vertically aligned β-Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NW. An enhancement in the UV region was observed in the photoluminescence spectra after annealing at 900 °C.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Excessive use of antibiotics contributes to the selection of resistant bacteria and intestinal colonization with multiresistant pathogens poses a risk factor for subsequent infections. The present study assessed vancomycin-resistant enterococci (VRE) carriage rates in patients admitted to our tertiary care hospital. Stool samples sent for routine culturing were screened with vancomycin containing solid or broth enrichment media. VRE isolates were identified with matrix-assisted laser desorption/ionization-time of flight mass spectrometry and antibiotic susceptibilities were tested by E-test. Vancomycin resistance genes were detected by polymerase chain reaction. Medical records of carriers were examined for suspected risk factors for colonization. Altogether 3025 stool specimens were analyzed. Solid media identified a VRE carriage rate of 2.2% while broth enrichment detected 5.8%. Seventy percent of the isolates were 〈em〉Enterococcus faecium. VanB〈/em〉 genotype was detected in 38.2%, 〈em〉VanA〈/em〉 in 37.3%, 〈em〉VanC1〈/em〉 in 22.6%, and 〈em〉VanC2〈/em〉 in 1.9%. All VRE were sensitive to linezolid, daptomycin, and tigecycline. Collective risk factors for carriage were diabetes, normal flora absence, 〈em〉Clostridioides difficile〈/em〉 positivity, longer hospital stay, and advanced age. 78.5% of the carriers received antibiotic therapy which was metronidazole in most cases (47.3%)〈em〉.〈/em〉 We recommend regular screening of risk groups such as patients with diabetes, history of recent hospitalization, or former 〈em〉C. difficile〈/em〉 infection as an imperative step for preventing VRE dissemination.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The propagation of surface acoustic wave (SAW) on the piezoelectric substrate requires conventionally an interdigitated electrode structure to excite the mechanical displacement at resonance frequency. The control of the electrode thickness could be useful to manipulate the energy confinement and the band dispersion of the surface guided mode. It has been demonstrated recently that high aspect ratio (HAR) electrode could produce a dispersive shear horizontal and vertically polarized surface modes in the bulk piezoelectric substrate. In this theoretical study, we propose to employ a high aspect ratio electrode on top of the GaN/sapphire-layered substrate enabling the presence of Sezawa surface mode. Based from the dispersion band, we obtained a higher frequency of surface guided mode in the non-radiative zone in the GaN/sapphire heterostructure configuration compared to the bulk GaN substrate. Indeed, these guided modes are induced by the hybridization between Sezawa surface mode and the mechanical resonance of the HAR electrode producing nearly a flat band at the limit of First Brillouin Zone. Furthermore, the displacement of each guided modes indicates the confinement of energy mostly in the electrode with a slight amount of energy in the top layer of the substrate. We demonstrated also the frequency tuning of guided mode using diverse materials for the electrode but also the thickness of GaN layer. The obtained results could be useful for the development of high-frequency telecommunication and sensing device based on Sezawa surface acoustic wave.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This work aimed to investigate alpha, proton, neutron and gamma shielding qualifications of different bulk metallic glasses (Zr〈sub〉65〈/sub〉Al〈sub〉7.5〈/sub〉Ni〈sub〉10〈/sub〉Cu〈sub〉17.5〈/sub〉, Ti〈sub〉40〈/sub〉Zr〈sub〉26〈/sub〉Be〈sub〉28〈/sub〉Fe〈sub〉6〈/sub〉, Cu〈sub〉49〈/sub〉Hf〈sub〉42〈/sub〉Al〈sub〉9〈/sub〉, Pd〈sub〉40〈/sub〉Ni〈sub〉40〈/sub〉P〈sub〉20〈/sub〉, Ni〈sub〉50〈/sub〉Pd〈sub〉30〈/sub〉P〈sub〉20〈/sub〉, and Ca〈sub〉65〈/sub〉Mg〈sub〉15〈/sub〉Zn〈sub〉20〈/sub〉) for nuclear security applications. Therefore, vital gamma radiation attenuation parameter namely mass attenuation coefficients (〈span〉 〈span〉\(\mu_{\rho }\)〈/span〉 〈/span〉) of investigated bulk metallic glasses (BMG) were determined using WinXCOM program. Next, half value layer (HVL), effective atomic number (〈em〉Z〈/em〉〈sub〉eff〈/sub〉), effective electron density (〈em〉N〈/em〉〈sub〉el〈/sub〉) and exposure buildup factors (EBF) were perused in a wide energy interval (0.02–20 MeV). Among the investigated samples, MG3 was found to be superior attenuator sample for gamma radiation, while MG6 was the least forceful glasses to reduce the photon intensity. The elements Pd and Hf in MG4, MG5 and MG3 were enhanced radiation shielding competences of the BMGs. Further, fast neutron removal cross-sections (〈span〉 〈span〉\(\sum R\)〈/span〉 〈/span〉) were evaluated to investigate neutron protection ability of the BMGs. Projected range (PR) and mass stopping power (MSP) values were obtained for proton (H〈sup〉1〈/sup〉) and alpha particles (He〈sup〉+2〈/sup〉). The outcomes showed that elemental composition of the metallic glasses was highly powerful on alpha, proton and neutron attenuation. It can be concluded that MG3 sample exhibited high nuclear shielding efficiency as deduced from the largest 〈span〉 〈span〉\(\mu_{\rho }\)〈/span〉 〈/span〉, Z〈sub〉eff〈/sub〉, and 〈span〉 〈span〉\(\sum R\)〈/span〉 〈/span〉, and the lowest HVL, EBF, MSP and PR values.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The authors aim to study the gamma-rays and neutron beam shielding capabilities of zinc bismuth borate glasses doped with erbium ions. Mass attenuation coefficient (MAC) (〈em〉μ〈/em〉/〈em〉ρ〈/em〉) values were computed employing XCOM and two different simulation codes, MCNP5 and Geant4, within 0.015–15 MeV photon energy, which showed good agreement within the derived values. The effective atomic number (〈em〉Z〈/em〉〈sub〉eff〈/sub〉), electron density (〈em〉N〈/em〉〈sub〉e〈/sub〉), half-value layer (HVL) and mean free path (MFP) values were derived using MAC values. To account on the scattering effects of photons from the samples, exposure buildup factor (EBF) were determined, applying geometric progression (G-P) method, within 0.015–15 MeV photon energy and penetration depth of 1–40 mfp (intervals: 1, 5, 10, 15, and 40 mfp). The high MAC, 〈em〉Z〈/em〉〈sub〉eff〈/sub〉 values and low HVL, MFP values of 16.93B〈sub〉2〈/sub〉O〈sub〉3〈/sub〉‒22.57ZnO‒60Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉‒0.5Er〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 (mol%) glass optimized its shielding effects against gamma-rays. The macroscopic effective removal cross-section for fast neutron (Σ〈sub〉R〈/sub〉) values lie within the range of 0.1142–0.1232 cm〈sup〉−1〈/sup〉 for the selected Er〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-doped samples. The studied parameters of the experimented glasses revealed their dominant radiation shielding features compared to commercial shielding glasses, concretes, and alloys.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We investigate the structural, magnetic, electronic, and mechanical properties of the full Heusler alloys (FHAs) Ti〈sub〉2〈/sub〉CoTl〈sub〉1−〈em〉x〈/em〉〈/sub〉Pb〈sub〉〈em〉x〈/em〉〈/sub〉 (〈em〉x〈/em〉 = 0.00, 0.25, 0.50, 0.75, 1.00) using first-principles calculations. The FHAs Ti〈sub〉2〈/sub〉CoTl〈sub〉1−〈em〉x〈/em〉〈/sub〉Pb〈sub〉〈em〉x〈/em〉〈/sub〉 have the half-metallic characters within lattice constant regions 5.799–6.707, 5.749–6.821, 5.749–6.982, 5.789–7.115, and 5.976–6.943 Å for 〈em〉x〈/em〉 = 0.00, 0.25, 0.50, 0.75, and 1.00, respectively. The negative formation energy, positive cohesion energy, and higher than room temperature Curie temperature indicate that the FHAs Ti〈sub〉2〈/sub〉CoTl〈sub〉1−〈em〉x〈/em〉〈/sub〉Pb〈sub〉〈em〉x〈/em〉〈/sub〉 are thermodynamically stable and can be used in spintronics and magnetoelectronics. The total magnetic moment per formula unit 〈span〉 〈span〉\(\mu_{\text{t}}\)〈/span〉 〈/span〉 of the FHAs Ti〈sub〉2〈/sub〉CoTl〈sub〉1−〈em〉x〈/em〉〈/sub〉Pb〈sub〉〈em〉x〈/em〉〈/sub〉 satisfies the Slater–Pauling rule 〈span〉 〈span〉\(\mu_{\text{t}} = Z{}_{\text{t}} - 18\)〈/span〉 〈/span〉, where 〈span〉 〈span〉\(Z_{\text{t}}\)〈/span〉 〈/span〉 represents the total number of valence electrons per formula unit. With increasing Pb atom concentration 〈em〉x〈/em〉, the band structures in both spin-up and spin-down channels move toward low energy region, but the spin-down indirect band gap 〈span〉 〈span〉\(E_{g}^{ \downarrow }\)〈/span〉 〈/span〉 increases. In addition, the calculated elastic constants and elastic modulus indicate that the FHAs Ti〈sub〉2〈/sub〉CoTl〈sub〉1−〈em〉x〈/em〉〈/sub〉Pb〈sub〉〈em〉x〈/em〉〈/sub〉 have mechanical stability, as well as ductility and strong resistance to fracture and plastic deformation.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉For this proposed work, the electrical and ferroelectric properties of metal–ferroelectric–insulator–silicon (MFeIS) and metal–ferroelectric–insulator–metal (MFeIM) capacitors with Bi〈sub〉4〈/sub〉Ti〈sub〉3〈/sub〉O〈sub〉12〈/sub〉 (BIT) ferroelectric film deposited on HfO〈sub〉2〈/sub〉/Si substrate were investigated. Physical vapor deposition technique (RF sputtering) was carried out for the deposition of 100 nm ferroelectric and high-k dielectric film of 5, 10 and 15 nm thickness. The structural properties such as crystallographic phase, grain size with composition and refractive index of the deposited films were measured by X-ray diffraction, field emission scanning electron microscopy with energy dispersive spectroscopy (FESEM-EDS) and multiple angle ellipsometry. Metal/ferroelectric/silicon (MFeS), metal/ferroelectric/metal (MFeM), metal/insulator/silicon (MIS), MFeIS and MFeIM structures were fabricated to obtain the electrical and ferroelectric properties. Investigation shows that the MFeIS structure with 10 nm buffer layer demonstrates improved memory window of 8.81 V as compared to the 3.3 V in the MFeS structure. MFeIM with 10 nm HfO〈sub〉2〈/sub〉 buffer layer shows maximum remnant polarization of 4.05 μC/cm〈sup〉2〈/sup〉. MFeI (10 nm) S structure even shows endurance higher than 10〈sup〉13〈/sup〉 read/write cycles and data retention for more than 10 years. The reliability of the ferroelectric and ferroelectric/dielectric stack was obtained by measuring the breakdown voltage characteristics.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this work, a reduced graphene oxide (0, 10, 30, 50 and 70 wt%) functionalized with Cu〈sub〉0.3〈/sub〉Mn〈sub〉0.7〈/sub〉Fe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 (CMFO) nanocomposites (rGO/CMFO) was successfully prepared by two techniques, namely modified Hummers (rGO) and sol–gel auto-ignition techniques (CMFO). The structure, morphology, magnetic and electrical properties of obtained nanocomposites have been examined using X-ray diffraction technique, Raman radiation spectroscopy, high-resolution transmission electron microscopy and vibrating sample magnetometer. The increase of rGO decreases the particle size of CMFO. It also results in a decrease in the saturation magnetization of the composites from 37.96 to 13.29 emu/g. The coercivity of composites elucidated higher values than those of the pristine composite due to interface interaction between CMFO and rGO. Colossal enhancement in electrical conductivity, dielectric constant and dielectric loss occurred with increasing the rGO content. These results indicate that rGO/CMFO composites can be a good candidate for many electronic applications such as spintronic magnetic storage, high-energy storage device and microwave absorption material.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The objectives of this study were (i) to isolate and characterize of cultivable denitrifying bacteria using classic microbiological and molecular methods, (ii) to compare of 16S rRNA and 〈em〉nosZ〈/em〉 genes as molecular markers, (iii) to determine bacterial community structure and diversity in soil samples using single-strand conformation polymorphism (SSCP) analysis. In this study, 49 bacterial isolates were cultivated and phylogenetic analyses grouped them into two phyla: 〈em〉Proteobacteria〈/em〉 (37 species) and 〈em〉Firmicutes〈/em〉 (12 species). Our study showed that the 〈em〉nosZ〈/em〉 functional gen could be used to identify denitrifying bacteria abundance in environment but could not be used to identify pure bacterial cultures. In addition, the bacterial community structure showed significant differences among the various soil types. Phylogenetic analysis of community structure indicated that 51 clones could be divided into 2 phylotypes. Uncultured bacteria (80.4%) and 〈em〉Gammaproteobacteria〈/em〉 (19.6%) were the dominant components of the soil bacterial community. For 16S rRNA, PCR products of 49 bacteria were obtained with 27F-1492R primer pairs. For 〈em〉nosZ〈/em〉, PCR products were obtained with primers 1F-1R (259 bp), 2F-2R (267 bp), and F-1622R (453 bp) of 39 bacteria that the single 〈em〉nosZ〈/em〉 band provided on the agarose gel. The bacterial 16S rRNA gene clone library was dominated by 〈em〉Gammaproteobacteria〈/em〉 and 〈em〉Bacilli〈/em〉. The 〈em〉nosZ〈/em〉 clone sequences did not represent the bacteria from which they were obtained but were found to be closer to the environmental clones. Our study showed that the 〈em〉nosZ〈/em〉 functional gene could be used to identify denitrification abundance in environment but could not be used to identify pure bacterial cultures. It was also found that the 〈em〉nosZ〈/em〉 sequences showed uncultured denitrifier species.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/SnO〈sub〉2〈/sub〉 semiconductor nanocomposites with various mole ratios were prepared by a simple chemical synthesis process that based on sol–gel method. The structural properties were determined by X-ray diffraction and scanning electron microscope technique. The XRD study reveals that no impurity phase, such as ZnO, Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, existed in all the samples. The average grain size was found to be about 39.51 nm when the mole ratio of ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/SnO〈sub〉2〈/sub〉 is 2:1 (Z2S1), which is benefit for improving gas sensing property. The Z2S1 sample showed a relatively higher response (11.46) at a lower working temperature (176 °C) to acetone compared with other composites, and the response/recovery time were both very short. The improving gas sensing properties may be due to the fine grain and the formation of the ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/SnO〈sub〉2〈/sub〉 heterojunction structure.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Nanocrystalline MgZn〈sub〉(1−〈em〉x〈/em〉)〈/sub〉O:〈em〉x〈/em〉Cr〈sup〉3+〈/sup〉 powders with 0.25 ≤ 〈em〉x〈/em〉 ≤ 3.0 mol% were synthesized using the combustion method. Crystallization of MgZn〈sub〉(1−〈em〉x〈/em〉)〈/sub〉O:〈em〉x〈/em〉Cr〈sup〉3+〈/sup〉 was investigated using the X-ray diffraction (XRD) technique which point towards significant reduction in crystallite size for MgZnO samples with increasing Cr〈sup〉3+〈/sup〉 concentration. Transmission electron microscopy revealed nanosized grains of the powder. UV–Vis spectroscopy and photoluminescence spectroscopy were employed to establish the electronic and optical properties of nanoparticles. Doping of Cr content from 0.25 to 3 mol% MgZnO facilitated tuning of bandgap in the range 3.37–3.43 eV. In addition to this, PL properties of the samples show that MgZn〈sub〉(1−〈em〉x〈/em〉)〈/sub〉O:〈em〉x〈/em〉Cr〈sup〉3+〈/sup〉 possess emission peak at 589 nm. Under excitation at 325 nm, the material exhibits an orange emission with highest relative intensity achieved for 0.25 mol% Cr〈sup〉3+〈/sup〉. This material may be explored as a new phosphor to be excited by UVA emitting AlGaN LEDs for optical devices and displays.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉To realize double-band perfect absorption, in this paper, we present a theoretical study of plasmonic absorption based on a metal–dielectric grating nanostructure. The structure consists of subwavelength periodic 〈span〉 〈span〉\( {\text{Al}}_{2} {\text{O}}_{3} \)〈/span〉 〈/span〉 grating covered with metal grating with a metal substrate. Results show that the one of the two absorption bands is caused by the Fabry–Perot resonance in the gold grating slits, and the other absorption band is caused by the gap plasmonic resonance of the 〈span〉 〈span〉\( {\text{Al}}_{2} {\text{O}}_{3} \)〈/span〉 〈/span〉 dielectric grating. The effect of structural parameters on absorption is also studied, the field distribution of the proposed nanostructure is presented to illustrate the absorption mechanism. Moreover, the two absorption peaks can be adjusted individually with different geometrical parameters. The results will pave the way towards the design of double-band plasmonic perfect absorber, which may have potential application in plasmonic absorption switch, plasmonic sensors and photodetectors.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The effect of germanium doping on the properties of hexagonal boron nitride and graphene monolayers was investigated using ab initio calculations. For boron nitride, the obtained results indicate the formation of electronic states in the region of the gap, near the Fermi level. The incorporation of such impurity atoms also induces an apparent decrease in the energy gap and a significant reduction in the optical conductivity. The calculations indicate small absorbance for wavelengths from infrared to visible light. For the graphene layer, it has been obtained a null gap semi-metal material. This result can be associated with the corresponding displacement of the Fermi level. In addition, the germanium doped graphene shows similar optical properties when compared with the pristine layer.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The effect of strain on the electronic and optical properties of ATaO〈sub〉2〈/sub〉N (A = Ca, Sr and Ba) is investigated using the first-principles hybridization functional calculations. The electronic and optical properties under the strains of − 8 to  + 8% in (100) and (010) directions are investigated. The results demonstrate that the band energy gap, band edges, absorption, reflectivity, and refractive index are obviously affected by the strains. Moreover, the effects of strains in (100) direction on all the considered properties of ATaO〈sub〉2〈/sub〉N are more obvious than those in (010) direction. The enhanced absorption in the visible light region is also found, which implies that ATaO〈sub〉2〈/sub〉N can well respond to the visible light. The present findings could provide a helpful reference to design photoelectronic materials with ATaO〈sub〉2〈/sub〉N by strain engineering.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Vancomycin is often used in orthopedic surgery as a local prophylaxis of bacterial infection. The aim of this work was to compare the release of vancomycin and its biologically inactive crystalline degradation products (CDP-1) during in vitro experiments from different types of local antibiotic delivery systems (bone grafts and bone cements). The concentrations of vancomycin and its crystalline degradation products were determined by high-performance liquid chromatography. Each experiment was performed in a phosphate buffer solution over 21 days. Morselized bone grafts, synthetic bone cements Palacos and Copal, and synthetic bone grafts were tested as local carriers of vancomycin. The highest concentration approximately 670 mg/L of vancomycin was released from synthetic bone grafts Actifuse. Even after 21 days, the concentration of vancomycin was still above the minimum inhibitory concentration (MIC). The maximum concentration of vancomycin released in two experiments with human bone grafts exceeded 600 mg/L during the first day and was still above MIC level 21 days later when the experiment was concluded. By comparing the synthetic bone cements Palacos and Copal, Copal had the average maximum concentration of only 32.4 mg/L and Palacos 35.7 mg/L. The concentration of vancomycin fell below the MIC for vancomycin-resistant 〈em〉Staphylococcus aureus〈/em〉 (VRSA) on the seventh day with Palacos and the ninth day with Copal. This study showed the insufficient concentration of released vancomycin from synthetic bone cements at the end of the experiment. For improvement of local prophylaxis, it would be beneficial to increase the amount of vancomycin in bone cements.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We report on the systematic first-principle calculations of the formation volumes of a single Fe (neutral iron) in Si〈sub〉1−〈em〉x〈/em〉〈/sub〉Ge〈sub〉〈em〉x〈/em〉〈/sub〉 at various Ge compositions (〈em〉x〈/em〉 = 4.7–20.3%). The formation volume was defined as the derivative of the Fe formation energy with respect to the pressure within 0–0.8 GPa. Interestingly, the formation volume was found to be equivalent to the difference between the volumes of the relaxed bulk and defective structures. The formation volume versus ‘〈em〉x〈/em〉’ exhibited a nonlinear pattern with regions of Fe-induced volume contraction (within 〈em〉x〈/em〉 〈 50%, i.e., Si-rich region) and expansion (〈em〉x〈/em〉 〉 50%, i.e., Ge-rich region). These results explain the reported observation that Fe prefers Si-rich environment and that Ge does not favor to be a nearest neighbor to Fe.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The present study was designed to characterize six 〈em〉Trueperella〈/em〉 (〈em〉T.〈/em〉) 〈em〉abortisuis〈/em〉 strains, cultured over a period of 5 months from fetus and abortion material of six pigs of a single farm in Mecklenburg-West Pomerania federal state, Germany. It was of interest to investigate the epidemiological relationships of the six strains among each other and whether a single bacterial clone was responsible for the abortion situation of the single farm. All six strains were identified phenotypically, by MALDI-TOF MS analysis and by phylogenetic analysis based on 16S rRNA gene and 〈em〉gap〈/em〉 (encoding the glyceraldehyde 3-phosphate dehydrogenase) and 〈em〉tuf〈/em〉 (encoding elongation factor tu) gene sequencing. Further genotypic comparison was performed using different genomic DNA fingerprint methods including BOX-PCR, (GTG)〈sub〉5〈/sub〉-PCR, and three RAPD-PCRs. The sequence analysis of the genes 〈em〉gap〈/em〉 and 〈em〉tuf〈/em〉 and the genomic DNA fingerprinting results revealed, as noval findings, that the six 〈em〉T. abortisuis〈/em〉 strains cultured from a single farm represent six different bacterial clones showing a genetic variability of this bacterial species in the pig population. All six 〈em〉T. abortisuis〈/em〉 strains were isolated in mixed culture with several other bacterial species. However, the 〈em〉T. abortisuis〈/em〉 strain, generally found in high numbers, seemed to be responsible for the abortion situation in the farm.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Getting into a weakened organism, non-tuberculosis mycobacteria (NTMB) contact not only with the cells of the microorganism but also with the microflora of the human body; however, these interactions are poorly understood. The purpose of this work was to study the effect of NTMB supernatants on the properties of conditionally pathogenic microorganisms in their interaction with red blood cells. We used strains of non-tuberculous mycobacteria 〈em〉Mycobacterium iranicum〈/em〉 and 〈em〉M. rutilum〈/em〉, as well as strains of 〈em〉Staphylococcus epidermidis〈/em〉 and 〈em〉Escherichia coli〈/em〉. Using the fluorescence in situ hybridisation (FISH) method, the processes of adhesion to the surface of erythrocytes and the intra-erythrocyte penetration of cells of 〈em〉S. epidermidis〈/em〉 and 〈em〉E. coli〈/em〉 under the influence of NTMB supernatants were studied. To study changes in the haemoglobin molecule under the action of the supernatants of NTMB, spectral analysis was performed. Statistical processing was performed using STATISTIKA 6.0. The results showed that the supernatants of 〈em〉M. iranicum〈/em〉 and 〈em〉M. rutilum〈/em〉 increased the adhesion of conditionally pathogenic bacteria with a low level of AntiHbA to the surface of erythrocytes by 3–4 times. It also increased the intra-erythrocyte penetration of cells of 〈em〉S. epidermidis〈/em〉 and 〈em〉E. coli〈/em〉 relative to the control values. As a result of studying the haemoglobin spectrum of erythrocytes under the influence of 〈em〉M. iranicum〈/em〉, a decrease in the optical density values of oxyhaemoglobin by a factor of 2 relative to the values in the control sample was noted. Thus, the supernatants of NTMB have a multidirectional effect on the interaction of opportunistic microorganisms with erythrocytes, increasing the adhesive activity and the penetration of cells into the erythrocytes, as well as reducing the optical density of oxyhaemoglobin.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The aim of the present study was to develop an ion-selective electrode method for the continuous determination of the intracellular pH in 〈em〉Lactobacillus plantarum〈/em〉 using a small-scale bioreactor. This method employed a salicylate-selective electrode basing on the distribution of salicylic acid across the cytoplasmic membrane. This developed electrode responded to salicylate concentrations above 20 μmol/L with a Nernstian sensitivity. The energized and concentrated cells were added into a thermostated small-scale bioreactor that contained the salicylate anions dissolved in a 100 mmol/L potassium phosphate buffer at different pH values. The changes in salicylate concentration that occurred in the medium containing bacterial suspension were measured as a voltage change. The cells of 〈em〉Lactobacillus plantarum〈/em〉 showed maintenance of pH homeostasis at the studied pH ranging from 4.0 to 7.0, and they kept a neutral intracellular pH up to 5.8. The simplicity of the measuring preparation and the relatively low cellular concentration, as well as the advantages of the small-scale bioreactor, lead us to believe that the described method can facilitate the study of the physicochemical factors on the intracellular pH of lactic acid bacteria using a single pH probe in one method.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Microbial contamination poses a great threat to aviation system security through mechanisms such as microbiologically influenced corrosion (MIC), fuel filter clogging, and fuel deterioration. In this study, a survey of microbial contamination in aviation fuel obtained from aircraft fuel tanks was performed to test the relationship between microbial contamination and aircraft service life. The contaminating microorganisms were counted, isolated, identified, and subjected to preliminary characterization. A low risk of microbial contamination in the selected samples was confirmed, and there was no significant difference in the counts between culturable bacteria and fungi (〈em〉p〈/em〉 〉 0.05). Phylogenetic analysis tree indicated that the diversity of culturable microorganisms was rather low, with 17 bacterial isolates belonging to 13 genera and 12 fungal isolates belonging to 5 genera. No yeast was isolated. The growth characteristics of these isolates indicated that the aircraft fuel tanks harbored various microorganisms that were able to utilize the aviation fuel as a source of carbon and energy. Meanwhile, some isolates caused emulsification and produced acid. The conclusions of this study were that various hazardous microorganisms can root in aircraft aviation fuel tanks. There was no relationship between microbial contamination and aircraft service life (〈em〉p〈/em〉 〉 0.05), and continuous good maintenance suppressed microbial proliferation.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The antifouling, antimicrobial, elution behavior, skin irritant, and cytotoxicity properties of water-soluble phosphate glass on stainless steel were evaluated. Water-soluble phosphate glass samples with 35% Cu (mol/mol) were prepared by altering the network modifier (Na〈sub〉2〈/sub〉O, K〈sub〉2〈/sub〉O) and network former (P〈sub〉2〈/sub〉O〈sub〉5〈/sub〉, B〈sub〉2〈/sub〉O〈sub〉3〈/sub〉) compositions. The materials were melted at temperatures within the range of 850–950 °C. The melt was then quenched and ground into fine particles using a twin roll mill. The resulting water-soluble glasses were prepared as glass frit (size 〈 100 μm) using a sieve. The amorphous phase was determined by X-ray diffraction and differential thermal analysis. Water-soluble glasses with a reduced Cu ion elution rate of 1.2 ppm per week were formed because the chemical resistances of the formulated glasses improved as the P〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 content decreased and the B〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 content increased. To test its antifouling properties, the glass frit was mixed with paint and coated onto a STS316L sheet. The surface roughness was increased markedly from 1.4 to 19.2 nm, increasing the specific surface area for antimicrobial activity. It was demonstrated that the proposed method was able to form noncytotoxic, nonirritant, water-soluble glasses with 99.9% antimicrobial activity against 〈em〉Staphylococcus aureus.〈/em〉 These results suggest that water-soluble phosphate glass on STS316L sheets could be useful in filtration plants.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Nosocomial infections are an important cause of morbi-mortality worldwide. The increase in the rate of resistance to conventional drugs in these microorganisms has stimulated the search for new therapeutic options. The nitro moiety (NO〈sub〉2〈/sub〉) is an important pharmacophore of molecules with high anti-infective activity. We aimed to synthesize new nitro-derivates and to evaluate their antibacterial and anti-〈em〉Candida〈/em〉 potential in vitro〈em〉.〈/em〉 Five compounds [3-nitro-2-phenylchroman-4-ol (〈strong〉3〈/strong〉); 3-nitro-2-phenyl-2H-chromene (〈strong〉4a〈/strong〉); 3-nitro-2-(4-chlorophenyl)-2H-chromene (〈strong〉4b〈/strong〉); 3-nitro-2-(4-fluorophenyl)-2H-chromene (〈strong〉4c〈/strong〉), and 3-Nitro-2-(2,3-dichlorophenyl)-2H-chromene (〈strong〉4d〈/strong〉)] were efficiently synthesized by Michael-aldol reaction of 2-hydroxybenzaldehyde with nitrostyrene, resulting in one β-nitro-alcohol (〈strong〉3〈/strong〉) and four nitro-olefins (〈strong〉4a〈/strong〉–〈strong〉4d〈/strong〉). The antibacterial and anti-〈em〉Candida〈/em〉 potentials were evaluated by assaying minimal inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and minimum bactericidal concentration (MBC). Mono-halogenated nitro-compounds (〈strong〉4b〈/strong〉 and 〈strong〉4c〈/strong〉) showed anti-staphylococcal activity with MIC values of 15.6–62.5 μg/mL and MBC of 62.5 μg/mL. However, the activity against Gram-negative strains was showed to be considerably lower and our data suggests that this effect was associated with the outer membrane. Furthermore, nitro-compounds 〈strong〉4c〈/strong〉 and 〈strong〉4d〈/strong〉 presented activity against C〈em〉andida〈/em〉 spp. with MIC values ranging from 7.8–31.25 μg/mL and MFC of 15.6–500 μg/mL. In addition, these compounds were able to induce damage in fungal cells increasing the release of intracellular material, which was associated with actions on the cell wall independent of quantitative changes in chitin and β-glucan. Together, these findings show that nitro-compounds can be exploited as anti-staphylococcal and anti-〈em〉Candida〈/em〉 prototypes.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Flap endonuclease is a structure-specific nuclease which cleaves 5′-flap of bifurcated DNA substrates. Genome sequence of 〈em〉Thermococcus kodakarensis〈/em〉 harbors an open reading frame, Tk1281, exhibiting high homology with archaeal flap endonucleases 1. The corresponding gene was cloned and expressed in 〈em〉Escherichia coli〈/em〉, and the gene product was purified to apparent homogeneity. Tk1281 was a monomer of 38 kDa and catalyzed the cleavage of 5′-flap from double-stranded DNA substrate containing single-stranded DNA flap. The highest cleavage activity was observed at 80 °C and pH 7.5. Under optimal conditions, Tk1281 exhibited apparent 〈em〉V〈/em〉〈sub〉max〈/sub〉 and 〈em〉K〈/em〉〈sub〉m〈/sub〉 values of 278 nmol/min/mg and 37 μM, respectively, against a 54-nucleotide double-stranded substrate containing a single-stranded 5′-flap of 27 nucleotides. A unique feature of Tk1281 is its highest activation in the presence of Co〈sup〉2+〈/sup〉 and no activation with Mn〈sup〉2+〈/sup〉. To the best of our knowledge, this is the first cloning and characterization of a flap endonuclease from the genus 〈em〉Thermococcus〈/em〉.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉〈em〉Chromera velia〈/em〉 is a marine photosynthetic relative of human apicomplexan parasites. It has been isolated from coral reefs and is indicted for being involved in symbioses with hermatypic corals. 〈em〉C. velia〈/em〉 has been subject to intensive research, but still very little is known of its response to light quality and quantity. Here, we have studied the growth and compositional responses of 〈em〉C. velia〈/em〉 to culture under monochromatic light (blue, green or red), at two photon flux densities (PFD, 20 and 100 μmol photons m〈sup〉−2〈/sup〉 s〈sup〉−1〈/sup〉). Our results show that 〈em〉C. velia〈/em〉 growth rate is unaffected by the quality of light, whereas it responds to PFD. However, light quality influenced cell size, which was smaller for cells exposed to blue monochromatic light, regardless of PFD. PFD strongly influenced carbon allocation: at 20 μmol photons m〈sup〉−2〈/sup〉 s〈sup〉−1〈/sup〉, carbon was mainly allocated into proteins while at 100 μmol photons m〈sup〉−2〈/sup〉 s〈sup〉−1〈/sup〉, carbon was allocated mainly into carbohydrate and lipid pools. The blue light treatment caused a decrease in the lipids and carbohydrates to proteins and thus suggested to affect nitrogen metabolism in acclimated cells. Whole-cell absorption spectra revealed the existence of red-shifted chlorophyll 〈em〉a〈/em〉 antenna not only under red light but in all low PFD treatments. These findings show the ability of 〈em〉C. velia〈/em〉 to successfully adapt and thrive in spectrally very different environments of coral reefs.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This paper presents the role of the conventional and Soliton wave model deposition at low substrate temperature (300–100 K) on the structural, electric and magnetic properties of Co〈sub〉35〈/sub〉Fe〈sub〉65〈/sub〉 thin films deposited by thermal evaporation using bulk polycrystalline Co〈sub〉35〈/sub〉Fe〈sub〉65〈/sub〉 alloy. On account of obtaining superior quality magnetic thin films without any high temperature growth processes or heat treatment, the Soliton wave growth model at suitable low temperature range is used. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are employed to investigate the various structural properties. Morphological and structural analyses of entire 30 nm Co〈sub〉35〈/sub〉Fe〈sub〉65〈/sub〉 thin films deposited on Si (100) substrate reveal that the stoichiometry is preserved over the whole temperature deposition and BCC crystalline formed with (110) texture. To attain the electrical and magnetic properties, resistivity and vibrating-sample magnetometer (VSM) measurements are evaluated. Soliton wave model deposition significantly increased magnetic anisotropy constant 〈em〉K〈/em〉〈sub〉1〈/sub〉 = 0.105 Merg/cm〈sup〉3〈/sup〉, 〈em〉M〈/em〉〈sub〉R〈/sub〉/〈em〉M〈/em〉〈sub〉S〈/sub〉 = 0.83 and coercivity 〈em〉H〈/em〉〈sub〉C〈/sub〉 = 272 Oe at 300 K when the compared to conventional deposition range in this work (〈em〉K〈/em〉〈sub〉1〈/sub〉 = 0.014 Merg/cm〈sup〉3〈/sup〉, 〈em〉M〈/em〉〈sub〉R〈/sub〉/〈em〉M〈/em〉〈sub〉S〈/sub〉 = 0.6 and 〈em〉H〈/em〉〈sub〉C〈/sub〉 = 50 Oe). Growth with novel approach of Co〈sub〉35〈/sub〉Fe〈sub〉65〈/sub〉 thin films highlights the reasonable low coercivity, the high saturation magnetization, the high magnetic anisotropy and the low electrical resistivity values, with tailored grain size, make them feasible to use in magnetic sensor technology in the near future.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Sewage not only contains water-soluble contaminants but water-insoluble contaminants as well. Superhydrophobic CdS–melamine foam prepared in this research satisfies the requirements of water purification. The photocatalyst CdS effectively adsorbs light energy to generate active species (⋅O〈sub〉2〈/sub〉〈sup〉−〈/sup〉) for degrading water-soluble pollutants. At the same time, superhydrophobic/superoleophilic characteristic of the melamine sponge can be utilized to remove water-insoluble pollutants. Finally, the degradation mechanism of materials was obtained by studying the parameters such as band gap and valence band structure, as well as by analyzing the experimental data of active species.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This work presents a physics-based analytical modeling methodology for the prediction of the lack-of-fusion porosity in powder bed metal additive manufacturing (PBMAM) considering the molten pool geometry, powder size variation, and packing. The presented model has promising short computational time without resorting to the finite element method or any iteration-based simulations. The temperature profiles were calculated using a closed-form temperature solution. Multiple transverse sectional areas of the molten pool geometry were plotted on a cross-sectional area of the part based on hatch space and layer thickness to calculate the lack-of-fusion area. The powder bed porosity was calculated using advancing front approach with consideration of powder statistical distribution and powder packing. The part porosity was converted from the calculated lack-of-fusion area by multiplying the calculated powder bed porosity. Acceptable agreements were observed upon validation against experimental measurements under various process conditions in PBMAM of Ti6Al4V. The computational time was recorded less than 26 s for the porosity calculation of five consecutive layers. The presented model has high prediction accuracy and high computational efficiency, which allow the porosity calculation for large-scale parts and process parameters planning through inverse analysis, and thus improves the usefulness of analytical modeling in real applications.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The mixture of the Ti–Mo–Nb–Al–Si matrix powder and Carbon nanotubes (CNTs) particles was used as the starting powder to produce the in-situ TiC reinforced TMCs using reaction synthesis method. The effect of the adding various CNTs content on the microstructure, phase composition, hardness, and oxidation behavior of the composites was investigated. The results show that the phases of the composites were composed of mainly α-Ti, β-Ti and TiC. With the increase of adding CNTs content, the porosity increased gradually, and the hardness initially increased and then decreased. The hardness of the composites with adding 1.0 wt% CNTs content was 496.1 HV, which was about 13.89% higher than that of the matrix alloy. With the increase of adding CNTs content, the oxidation mass gain first decreased and then increased. The oxidation mass gain of composites with adding 1.0 wt% CNTs content was 2.212 mg cm〈sup〉−2〈/sup〉, which was about 63.33% less than that of the matrix alloy, and the parabolic rate constant (〈em〉k〈/em〉〈sub〉p〈/sub〉) was the minimum, which was 1.67 × 10〈sup〉−3〈/sup〉 mg〈sup〉2〈/sup〉 cm〈sup〉−4〈/sup〉 h〈sup〉−1〈/sup〉. The oxidation resistance of the composites was better than the matrix alloy.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The following series of articles form a special issue organized by the Algatech Center of the Institute of Microbiology CAS dedicated to the memory of Dr. Ivan Šetlík.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The rapid emergence of resistance in pathogenic bacteria together with a steep decline in economic incentives has rendered a new wave in the drug development by the pharmaceutical industry and researchers. Since cyanobacteria are recognized as wide producers of pharmaceutically important compounds, we investigated thirty-four cyanobacterial extracts prepared by solvents of different polarities for their antimicrobial potential. Almost all tested cyanobacterial strains exhibited some degree of antimicrobial bioactivity, with more general effect on fungal strains compared with bacteria. Surprisingly ~50% of cyanobacterial extracts exhibited specific activity against one or few bacterial indicator strains with Gram-positive bacteria being more affected. Extracts of two most promising strains were subjected to activity-guided fractionation and determination of the minimum inhibitory concentration (MIC) against selected bacterial and fungal isolates. Multiple fractions were responsible for their antimicrobial effect with MIC reaching low-micromolar concentrations and in some of them high level of specificity was recorded. Twenty-six bioactive fractions analyzed on LC-HRMS/MS and Global Natural Product Social Molecular Networking (GNPS) online workflow using dereplication resulted in identification of only forty-nine peptide spectrum matches (PSMs) with eleven unique metabolites spectrum matches (MSMs). Interestingly, only three fractions from 〈em〉Nostoc calcicola〈/em〉 Lukešová 3/97 and four fractions from 〈em〉Desmonostoc〈/em〉 sp. Cc2 showed the presence of unique MSMs suggesting the presence of unknown antimicrobial metabolites among majority of bioactive fractions from both the strains. Our results highlight potential for isolation and discovery of potential antimicrobial bioactive lead molecules from cyanobacterial extracts.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Citrus black spot (CBS) and post-bloom fruit drop (PFD), caused by 〈em〉Phyllosticta citricarpa〈/em〉 and 〈em〉Colletotrichum abscissum〈/em〉, respectively, are two important citrus diseases worldwide. CBS depreciates the market value and prevents exportation of citrus fruits to Europe. PFD under favorable climatic conditions can cause the abscission of flowers, thereby reducing citrus production by 80%. An ecofriendly alternative to control plant diseases is the use of endophytic microorganisms, or secondary metabolites produced by them. Strain LGMF1631, close related to 〈em〉Diaporthe〈/em〉 cf. 〈em〉heveae〈/em〉 1, was isolated from the medicinal plant 〈em〉Stryphnodendron adstringens〈/em〉 and showed significant antimicrobial activity〈em〉,〈/em〉 in a previous study. In view of the potential presented by strain LGMF1631, and the absence of chemical data for secondary metabolites produced by 〈em〉D.〈/em〉 cf. 〈em〉heveae〈/em〉, we decided to characterize the compounds produced by strain LGMF1631. Based on ITS, TEF1, and TUB phylogenetic analysis, strain LGMF1631 was confirmed to belong to 〈em〉D.〈/em〉 cf. 〈em〉heveae〈/em〉 1. Chemical assessment of the fungal strain LGMF1631 revealed one new 〈em〉seco〈/em〉-dihydroisocoumarin [cladosporin B (〈strong〉1〈/strong〉)] along with six other related, already known dihydroisocoumarin derivatives and one monoterpene [(−)-(1〈em〉S〈/em〉,2〈em〉R〈/em〉,3〈em〉S〈/em〉,4〈em〉R〈/em〉)-〈em〉p〈/em〉-menthane-1,2,3-triol (〈strong〉8〈/strong〉)]. Among the isolated metabolites, compound 〈strong〉5〈/strong〉 drastically reduced the growth of both phytopathogens in vitro and completely inhibited the development of CBS and PFD in citrus fruits and flowers. In addition, compound 〈strong〉5〈/strong〉 did not show toxicity against human cancer cell lines or citrus leaves, at concentrations higher than used for the inhibition of the phytopathogens, suggesting the potential use of (−)-(3〈em〉R〈/em〉,4〈em〉R〈/em〉)-〈em〉cis〈/em〉-4-hydroxy-5-methylmellein (〈strong〉5〈/strong〉) to control citrus diseases.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The biogenesis of the cyanobacterial photosystem II (PSII) complex requires a number of auxiliary assembly factors that improve efficiency of the process but their precise function is not well understood. To assess a possible synergic action of the Ycf48 and Ycf39 factors acting in early steps of the biogenesis via interaction with the nascent D1 subunit of PSII, we constructed and characterised a double mutant of the cyanobacterium 〈em〉Synechocystis〈/em〉 PCC 6803 lacking both these proteins. In addition, we also deleted the 〈em〉ycf39〈/em〉 gene in the double mutant lacking Ycf48 and Pam68, the latter being a ribosomal factor promoting insertion of chlorophyll (Chl) into the CP47 subunit of PSII. The resulting double ΔYcf48/ΔYcf39 and triple ΔYcf48/ΔPam68/ΔYcf39 mutants were deficient in PSII and total Chl, and in contrast to the source mutants, they lost the capacity for autotrophy. Interestingly, autotrophic growth was restored in both of the new multiple mutants by enhancing Chl biosynthesis using a specific ferrochelatase inhibitor. Taking together with the weak radioactive labelling of the D1 protein, these findings can be explained by inhibition of the D1 synthesis caused by the lack and/or incorrect binding of Chl molecules. The results emphasise the key importance of the sufficient Chl supply for the PSII biogenesis and also support the existence of a so far enigmatic regulatory mechanism leading to the reduced overall Chl biosynthesis/accumulation when the PSII assembly is impaired.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The superhydrophobic fluorosilicone/silica (FS/SiO〈sub〉2〈/sub〉) hybrid composite coating was easily fabricated by one-step blending method in this study, whose durable superhydrophobicity could be ensured by fluorosilicone resin (FS) matrix and perfluorine-SiO〈sub〉2〈/sub〉 nanoparticles. The prepared perfluorine-SiO〈sub〉2〈/sub〉 nanoparticles were detected using FESEM and FT-IR spectra, and the wettability and dispersion effects were studied. The surface morphologies and hydrophobicity of FS/SiO〈sub〉2〈/sub〉 coating on glass plates were investigated by AFM and optical contact angle meter, while the adhesion, wear-resistance and chemical regent-resistance for FS/SiO〈sub〉2〈/sub〉 superhydrophobic coating were also discussed. At last, the self-cleaning and anti-icing performances of prepared FS/SiO〈sub〉2〈/sub〉 superhydrophobic coating were explored. It could be found that the FS coating doped with more than 22% SiO〈sub〉2〈/sub〉 would exhibit superhydrophobicity. The water contact angle of the superhydrophobic FS coating could reach 161° and sliding angle 2° in the best condition. The superhydrophobic FS/SiO〈sub〉2〈/sub〉 coating possesses relatively satisfied mechanical and chemical stability. Moreover, the prepared superhydrophobic FS/SiO〈sub〉2〈/sub〉 hybrid composite coating provided an available selection of protecting surfaces against contamination and icing which validated the practicability.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We studied the low-field microwave absorption (LFMA) in polycrystalline pellet and powdered (0.1–0.2 µm particle size) samples with a nominal composition of Zn〈sub〉1 − 〈em〉x〈/em〉〈/sub〉(Mn:Fe(Ni))〈sub〉〈em〉x〈/em〉〈/sub〉O (〈em〉x〈/em〉 = 0.02). LFMA signals are stronger in the case of Mn:Fe co-doped ZnO, as compared to that of Mn:Ni co-doped ZnO. While the bulk samples show hysteresis, it disappears in the case of powdered samples. Further the line shapes of LFMA were modified with powdering, leading to small saturation fields for LFMA. This indicates that the microwave absorption in these powders is more sensitive than in the pellet form. We interpret these results in terms of interparticle–interfacial pinning. In this work, we clearly establish the low-field tunability of microwave absorption in the Zn〈sub〉1 − 〈em〉x〈/em〉〈/sub〉(Mn:Fe(Ni))〈sub〉〈em〉x〈/em〉〈/sub〉O (〈em〉x〈/em〉 = 0.02) system, which is good for the applications as microwave absorbers with small field tunability as a functionality. This means LFMA can give inputs for the right choice of material for field-tunable microwave absorber design.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The spherification method was adapted to macroporous tetragonal polycrystalline zirconia ceramic fabrication from baddeleyite. Dependences of the material microstructure, its porosity, phase composition and mechanical properties on the sintering temperature were investigated. The opportunity for controlling the porosity and mechanical properties of produced spherical macroporous zirconia ceramic via the sintering temperature variation was revealed. Beads sintered at 1100 °С are characterized by the optimal combination of porosity, hardness, Young’s modulus and breaking force.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉When it comes to women’s health, treating vaginal infections makes up a high proportion of the gynecological services. Among the forms of vaginitis, vulvovaginal candidiasis (VVC) is considered the second most common. Demand for new treatment alternatives is increasingly relevant, especially for therapies with fewer side effects, better tolerability, and lower cost, while still offering improved quality of life in terms of disease prevention. This study intended to investigate the alternative therapies described for the adjuvant treatment of vulvovaginitis caused by 〈em〉Candida〈/em〉 species, including alternative and complementary treatment methods used by women. This literature review is based on articles written in English and Portuguese in the PubMed, Google Scholar, and SciELO databases. This study was conducted for the most part using the Brazilian Government’s Capes Periodicals Portal, which directs to Google Scholar and PubMed. Since the 1980s, there has been growing interest in alternative therapies in Brazil, a trend which also began in other Western countries in the second half of the twentieth century. Some alternative treatments include substances with antifungal activity, some substances help restore the balance of the vaginal microbiota, while others have an inhibitory activity on microbial virulence factors. The proper use of therapeutic alternatives can effectively contribute to the treatment of VVC, but it should be remembered that some chemical products, such as boric acid or vinegar, and even natural products such as propolis, garlic, and tea tree may have undesirable side effects, having not been tested by well-designed clinical studies. Even so, alternative therapies in the treatment of VVC do have support in the scientific literature.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Asymptomatic uropathogenic 〈em〉Escherichia coli〈/em〉 (UPECs) are the leading cause of asymptomatic bacteriuria (ABU) in humans. So this study aimed to identify and characterize ABU UPECs from hospitalized patients of Kolkata, India, with respect to their antibiogram profile, phylogeny, pathogenicity islands, and virulence factor gene acquisition and FimH mutations in comparison to symptomatic UPECs. 〈em〉E. coli〈/em〉 was detected biochemically in 44.44% (20/45) and 32.26% (20/62) of urine culture-positive asymptomatic and symptomatic hospitalized individuals respectively. Ninety-five percent of the asymptomatic isolates were multidrug resistant (MDR) compared to the symptomatic isolates (100%). Significant predominance of unknown phylogroup, pathogenicity island markers (PAI IV536, PAI I CFT073), and distribution patterns of different virulence factor genes respectively was evident among both groups. A significant correlation was observed between both groups of isolates with respect to their antibiotic resistances (except imipenem, amikacin, and nitrofurantoin), prevalence of phylogenetic groups and PAIs, and virulence factor gene (〈em〉fimH〈/em〉, 〈em〉papC〈/em〉, 〈em〉papEF〈/em〉, 〈em〉papGII〈/em〉, 〈em〉iucD〈/em〉, and 〈em〉cnf1〈/em〉) acquisition. Pathoadaptive FimH adhesin mutations, especially hot spot mutation V27A, were detected in 80% asymptomatic isolates mostly reported in symptomatic ones worldwide. Moreover, this is the first study from India that reported incidence of “Unknown” phylogroup, pathogenicity island markers, and potentially pathoadaptive FimH mutations in asymptomatic UPECs isolated from hospitalized patients which further indicated that these ABU 〈em〉E. coli〈/em〉 might have originated from their symptomatic counterparts due to unbridled use of unprescribed antibiotics. Therefore, this study demands antibiotic de-escalation along with regular and intricate monitoring at the molecular level for efficient management of ABU that addresses a major public health concern.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Mutations occurring in viral polymerase gene of hepatitis B virus (HBV) due to the use of nucleos(t)id analogs reduce the activity of the drugs by causing antiviral resistance. In this study, it was aimed to evaluate mutations responsible for drug resistance and drug resistance mutation rates in patients followed up by the diagnosis of chronic hepatitis B (CHB). A total of 318 CHB patients were included in the study. HBV mutations were detected using the INNO-LiPA commercial kit based on the reverse hybridization principle. Drug resistance mutation was detected in 46.86% (149/318) of the patients. The rates of drug resistance were found 36.79% (117/318) for lamivudine resistance, 12.58% (40/318) for entecavir (ETV), and 7.86% (25/318) for adefovir. In 10 patients, the possible tenofovir (TDF) resistance (3.14%) was found. Single-drug and double-drug resistances were detected in 34.59% and in 11.01% of the patients, respectively. Triple drug resistance was detected in only 1.26% of the patients. Unlike various studies in Turkey and in other countries, remarkable resistance to ETV and TDF were found in this study. The high rate of the probable TDF resistance was striking, with 3.14%.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Some strains of the genus 〈em〉Enterococcus〈/em〉 are effective probiotic bacteria if they meet safety and probiotic criteria. In our study, 17 canine enterococci previously selected from a group of 160 isolates based on safety criteria were screened for some functional properties relevant to their use as probiotics. The results of antimicrobial resistance testing showed sensitivity of eleven strains to EFSA recommended antimicrobials. In contrast, the most frequent resistance was observed for cefotaxim (15/17) and oxacillin (13/17). PCR detection of resistance genes (〈em〉vanA〈/em〉, 〈em〉vanB〈/em〉, 〈em〉vanC〈/em〉, 〈em〉tetM〈/em〉, 〈em〉tetL〈/em〉, 〈em〉ermB〈/em〉, and 〈em〉mefA〈/em〉) revealed the presence of 〈em〉mefA〈/em〉 gene in five 〈em〉Enterococcus faecium〈/em〉 strains and 〈em〉vanA〈/em〉 gene in one strain. The production of enzymes commonly associated with intestinal diseases was in general rare (β-glucosidase 2/17, α-chymotrypsin 1/17, 〈em〉N〈/em〉-acetyl-β-glucosaminidase 0/17, and β-glucuronidase 0/17). The measurement of strain survival rate (%) under the conditions simulating gastric (pH 2.5) and bile juices (0.3% bile) showed considerable differences between strains (〈 0.01 to 4.7% after 90 min for gastric juices, 48.0 to 254.0% after 180 min for bile). The concentration of produced 〈span〉l〈/span〉-lactic acid ranged between 83.1 to 119.3 mmol/L after 48 h cultivation depending on the strain. All strains fermented 16 out of 49 different carbohydrates (range from 17 to 23/49). Antimicrobial activity was recorded for two strains against some species of 〈em〉Listeria〈/em〉 sp. and 〈em〉Enterococcus〈/em〉 sp. Finally, two 〈em〉E. faecium〈/em〉 candidates (IK25 and D7) were selected for testing in dogs, and hereafter they could possibly extend the currently limited range of beneficial bacteria of canine origin used as a dietary supplement for dogs.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Paclobutrazol, (2RS, 3RS)-1-(4-chlorophenyl)-4, 4-dimethyl-2-(1H-1,2,4-triazol-1-yl) pentan-3-ol, is a plant growth retardant that mainly inhibits gibberellins (GAs) biosynthesis. In agricultural practice, paclobutrazol is applied to arrest vegetative growth so as to increase the reproductive growth of many orchard fruit, as well as grain crops. However, due to its over-application and chemical stability, paclobutrazol accumulates in soil and inhibits the growth of subsequent crops, especially those grown for vegetative purposes. The present study focused mainly on the changes in the soil bacterial community following application of paclobutrazol. Mung bean (〈em〉Vigna radiata〈/em〉) plants were treated with paclobutrazol and cultivated for three consecutive seasons. Soil samples were collected and analyzed by denaturing gradient gel electrophoresis (DGGE) using 16S rDNA gene fragments and clone library analyses. The results obtained through clustering and clonal sequencing analysis showed that the bacterial community was affected by paclobutrazol, and in addition, was more diverse in the third stage of mung bean plant cultivation. The results of the study showed that paclobutrazol affected bacterial composition, and the population of bacteria varied greatly across time.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The aim of this study was to evaluate the contribution of plasmid-mediated genes and efflux to fluoroquinolone resistance in collection of 〈em〉Achromobacter〈/em〉 spp. gathered during a 3-year period. Susceptibility to ciprofloxacin and levofloxacin was tested by disk diffusion and microdilution tests for a collection of 98 〈em〉Achromobacter〈/em〉 spp. clinical isolates. Identification of fluoroquinolone-resistant isolates was performed by sequencing and phylogenetic analyses of the 〈em〉nrdA〈/em〉 gene. Genetic relatedness among resistant isolates was determined by pulsed-field gel electrophoresis (PFGE) analysis. The influence of an H〈sup〉+〈/sup〉 conductor cyanide 〈em〉m〈/em〉-chlorophenyl hydrazone (CCCP) and a resistance-nodulation-division-type efflux pump inhibitor phenylalanine-arginine beta-naphthylamide (PAβN) on minimal inhibitory concentration (MIC) value was evaluated by broth microdilution. The presence of the plasmid-mediated 〈em〉qnrA〈/em〉, 〈em〉qnrB〈/em〉, 〈em〉qnrC〈/em〉, 〈em〉qnrS〈/em〉, and 〈em〉aac-(6′)-Ib-cr〈/em〉 genes was investigated by PCR and sequencing. 〈em〉Achromobacter〈/em〉 spp. isolates that were resistant or intermediately resistant to fluoroquinolones in disk diffusion tests (44/98) were subjected to microdilution. As a result, 20/98 isolates were confirmed to be resistant to ciprofloxacin while 10/98 was resistant to levofloxacin. CCCP decreased twofold MIC value for ciprofloxacin in six isolates and more than 16 times in one isolate, while MIC value for levofloxacin was decreased in all isolates (twofold to more than eightfold). Fluoroquinolone-resistant isolates were identified as 〈em〉A. xylosoxidans〈/em〉 with the 〈em〉nrdA〈/em〉 gene sequencing. PFGE revealed that resistant isolates belonged to seven different genotypes. Ten isolates belonging to four genotypes were positive for the 〈em〉aac-(6′)-Ib-cr〈/em〉 gene. Although resistance to fluoroquinolones was not widespread among analyzed isolates, detected contribution of efflux pumps and the presence of the 〈em〉aac-(6′)-Ib-cr〈/em〉 gene present a platform for emergence of more resistant strains.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The aim of this study was to determine the presence and prevalence of 〈em〉Wolbachia〈/em〉 bacteria in natural population of fleas (Insecta: Siphonaptera) in Turkey, and to exhibit the molecular characterization and the phylogenetic reconstruction at the positive isolates with other species in GenBank, based on 16S rDNA sequences. One hundred twenty-four flea samples belonging to the species 〈em〉Ctenocephalides canis〈/em〉, 〈em〉C. felis〈/em〉, and 〈em〉Pulex irritans〈/em〉 were collected from animal shelters in Kayseri between January and August 2017. All flea species were individually screened for the presence of 〈em〉Wolbachia〈/em〉 spp. by polymerase chain reaction (PCR) targeting the 16S ribosomal RNA gene. According to PCR analyses, 〈em〉Wolbachia〈/em〉 spp. were found prevalent in 〈em〉C. canis〈/em〉 and 〈em〉P. irritans〈/em〉 fleas, while it was not detected in the 〈em〉C. felis〈/em〉 species. Totally, 20 isolates were purified from agarose gel and sequenced with the same primers for molecular characterization and phylogenetic analyses. The sequence analyses revealed 17 polymorphic sites and 2 genetically different 〈em〉Wolbachia〈/em〉 isolates, representing two different haplotypes in two flea species. The distribution patterns, molecular characterization, and phylogenetic status of 〈em〉Wolbachia〈/em〉 spp. of fleas in Turkey are presented for the first time with this study. Understanding of the role of 〈em〉Wolbachia〈/em〉 in vector biology may provide information for developing 〈em〉Wolbachia〈/em〉-based biological control tools.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Thin films of Tb-doped CdO were grown on FTO substrates using the sol–gel-spin coater technique. XRD studies confirmed the polycrystalline cubic growth of the films with a (200) preferential orientation. XRD analysis was used to estimate the crystallite sizes, dislocation density, and microstrain values, and found that they are highly dependent on the doping percentage. Homogeneous distributions of the nano-gains were observed from the AFM studies. Energy-dispersive spectroscopy and mapping analyses were used for the uniform elemental composition confirmation. All the films displayed high transmission reaching nearly 80% in the visible spectrum and the effect of Tb doping was very clear by corresponding systematic increase in intensities. The direct band-gap values were estimated from the Tauc plots and are found to be highly tunable based on the doping percentage, which was varying between 2.79 and 2.91 eV. The refractive index and extinction coefficient values are lies between 1.8 and 2.5 and 0.44 to 0.82. The 〈span〉 〈span〉\({\chi ^{(1)}}\)〈/span〉 〈/span〉 values are found to be varying between of 0.05 to 0.45 within the range 1–4 eV. This suggests all the linear and nonlinear optical properties of the present samples can be tailored for the various applications by the doping.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, a continuum theory for describing the magnetostrictive behavior of magnetic nanofilms is proposed. Surface effects (including surface elastic and surface magnetoelastic effects) as well as symmetry lowering of nanofilms are considered in the theoretical scheme. The spherical symmetry is lowered to the cylindrical one in nearly two-dimensional nanofilms. And then, there are some additional new elastic and magnetoelastic parameters induced by symmetry lowering have to be reckoned into model the magnetostriction of nanofilms rigorously. The application of our theoretical scheme to Fe nanofilms shows good agreement with experiment. The magnetostriction minimum vs film thickness of Fe nanofilms was produced straightforwardly. In addition, the surface elastic and surface magnetoelastic constants are physically reasonable and consistent with most solid surfaces (on the order of 1–10 J/m〈sup〉− 2〈/sup〉 for surface elasticity and 10〈sup〉− 2〈/sup〉–10〈sup〉− 4〈/sup〉 J/m〈sup〉− 2〈/sup〉 for surface magnetoelasticity). This fact confirms the great importance of additional new elastic and magnetoelastic parameters in magnetostriction theory of magnetic nanofilms. The relationship (〈em〉λ〈/em〉〈sub〉x〈/sub〉 = − 2〈em〉λ〈/em〉〈sub〉y〈/sub〉 = − 2〈em〉λ〈/em〉〈sub〉z〈/sub〉) between magnetostrictions breaks down for nanofilms. In addition, when the magnetic field is applied along vertical direction, the magnetostriction of nanofilms behaves different from the case that magnetic field is applied along in-plane direction.〈/p〉

Beschreibung: 〈p〉The author of the original version of this article makes the following corrections:〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Porous mullites used as ceramic membranes were fabricated and coated with TiO〈sub〉2〈/sub〉 and 0.1 wt% Cu(II)-grafted TiO〈sub〉2〈/sub〉 powders. A spinning coating technique was applied for the coating process. Antibacterial activities of the coated mullites were tested against pathogenic bacteria 〈em〉Escherichia coli〈/em〉 (〈em〉E. coli〈/em〉) by following the experimental methods of ISO 17094:2014 standardized for testing photocatalyst materials under visible light of a florescent lamp as an indoor-tested condition. Mullites without coatings were used as control samples. After 4 h of light exposure, the number of the initially viable bacteria increased significantly for the uncoated mullites and decreased for all of the coated mullites. Coating layers of TiO〈sub〉2〈/sub〉 and Cu-grafted TiO〈sub〉2〈/sub〉 could inactivate 〈em〉E. coli〈/em〉 under light illumination. In dark condition, 0.1 wt% Cu(II)-grafted TiO〈sub〉2〈/sub〉 coating on the mullites could inactivate the bacteria, while TiO〈sub〉2〈/sub〉 coating on the mullites could not inactivate the bacteria. The experimental results provide a possibility of using the coated mullites for disinfection applications. Bacterial inactivation mechanisms of TiO〈sub〉2〈/sub〉 and Cu-grafted TiO〈sub〉2〈/sub〉 in coating layers were investigated and discussed in terms of microstructural observation on the coating layers.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Nitrogen doping is often used to expand the response range of wide-bandgap semiconductors to improve their photoelectrical properties. Unique morphology regulatory effect of NH〈sub〉4〈/sub〉〈sup〉+〈/sup〉 ions on one-dimensional TiO〈sub〉2〈/sub〉 nanorod arrays (TNAs) is proved in this research for the first time, but nitrogen-doping effect is hardly detected. Once NH〈sub〉4〈/sub〉Cl is added, the growth of TNAs is greatly promoted especially in radial direction, but little amount of nitrogen from NH〈sub〉4〈/sub〉〈sup〉+〈/sup〉 ions can enter the modified TNAs (N-TNAs). Furthermore, the bandgap energy of N-TNAs is almost unchanged compared with TNAs, meaning that trace nitrogen doping does not affect response ability to irradiation. When fabricated into dye-sensitized solar cells (DSSCs) with N-TNAs, the optimal photoelectrical conversion efficiency (3.16%) is nearly twice that with TNAs (1.62%). It is worth noting that the increased efficiency mainly results from the photoinduced current but not voltage. Second, the change of conversion efficiency is related to nanorod length. In summary, the improvement of photoelectrical property is caused by the directional growth of nanorods, which results from the addition of NH〈sub〉4〈/sub〉〈sup〉+〈/sup〉 ions as an effective structure regulatory agent.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Elastomeric cellular materials with different ordered microstructures are additively manufactured in this work. Via designing the microscale architectures, the cellular materials can distinguish their mechanical behaviors among uniaxial compressive, bending, and combinative deformations. Theoretical models are developed herein, and both calculation and experiment results note that the mechanical behaviors of the cellular materials highly depend on the filament layer height, the spacing, and the diameter. In comparison with traditional elastomeric cellular, the additively manufactured soft samples can finetune their mechanics to meet the different requests and would be beneficial in extensive applications.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Continuous increasing incidence of allergic diseases is calling for identifying early prognostic markers pointing to increased risk of allergy development and establishing protocols for preventive strategies limiting allergy development in predisposed individuals. It is important to better understand the critical events occurring in early postnatal life, especially the interaction of a newborn with microbial compounds important for the maturation of the neonatal immune system and setting immunoregulatory responses as well. Dendritic cells (DC) together with the cytokine microenvironment play an important role in priming of immune responses. The capacity of monocyte-derived DC (moDC) from cord blood of children of healthy and allergic mothers to respond to microbial antigens (〈em〉Escherichia coli〈/em〉 O86 (EcO86) and delipidated 〈em〉Bacillus firmus〈/em〉 (DBF)) was tested by flow cytometry and quantitative real-time PCR. Both EcO86 and DBF were able to promote maturation of moDC, but moDC of children of allergic mothers expressed higher levels of activation markers CD80 and CD83. Increased gene expression of IL-6 and lower expression of indol-amine 2,3 dioxygenase were observed in moDC of neonates of allergic mothers, in comparison to healthy ones. A higher gene expression and an increased presence of activation markers on moDC of newborns of allergic mothers indicate a generally higher reactivity of these cells, possibly enabling easier development of inappropriate immune response after an allergen encounter.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, an attractive, ultra-wideband, and polarization-insensitive fractal perfect metamaterial absorber had been proposed based on a tree-shaped microstructure. The absorber was composed of two dielectric substrates, a three-dimensional fractal metal tree, and four lumped resistances. The absorption mechanism and different modes for the absorber had been analyzed in simulation. The characters of polarized-insensitivity and wide-incident absorption for the proposed metamaterial absorber were systematically illuminated by the near electric fields, angular absorptions, and surface current distributions. A presented perfect metamaterial absorber device had been easily implemented using the common printed circuit board method and was measured in a microwave anechoic chamber. The results showed that this proposed FPMA provided a relative bandwidth of 86.9% with the absorptivity larger than 80%. Both the simulated and experimental results adequately verified the characters of wideband, wide-incident, and polarization-insensitive absorption.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Phase transformation characteristics of an aged NiTiHfPd shape memory alloy were investigated through thermal cycling experiments via the differential scanning calorimetry technique. Effects of heating/cooling rate and thermal cycling on the phase transformation temperatures, enthalpies, and thermal hysteresis values were revealed. It was found that phase transformation temperatures and thermal hysteresis values alter considerably with thermal cycling. The transformation temperatures were found to be above 80 °C for all the heating rates, which makes this alloy a promising candidate for high-temperature applications in the selected aging conditions.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Nanocrystalline Fe〈sub〉46〈/sub〉Co〈sub〉34〈/sub〉Ni〈sub〉20〈/sub〉 alloy powder was successfully fabricated by mechanical alloying. The alloy powder (mean particle size ~ 5.4 μm and grain size ~ 15 nm) was composed of two phases—the f.c.c. phase and the b.c.c. phase. At 300 K, the saturation magnetization (〈em〉M〈/em〉〈sub〉S〈/sub〉), the remanent magnetization (〈em〉M〈/em〉〈sub〉R〈/sub〉), and the intrinsic coercivity (〈em〉H〈/em〉〈sub〉CI〈/sub〉) of the as-fabricated alloy powder were ~ 169 Am〈sup〉2〈/sup〉kg〈sup〉− 1〈/sup〉, ~ 2 Am〈sup〉2〈/sup〉kg〈sup〉− 1〈/sup〉, and ~ 3.3 kAm〈sup〉− 1〈/sup〉, respectively. The nanocrystalline powder exhibited significantly superior soft-magnetic properties—decrease in 〈em〉H〈/em〉〈sub〉CI〈/sub〉 by ~ 15 times and increase in 〈em〉M〈/em〉〈sub〉S〈/sub〉 by ~ 30%—compared to the nanoparticles of similar compositions synthesized by chemical methods. The 〈em〉M〈/em〉〈sub〉S〈/sub〉, 〈em〉M〈/em〉〈sub〉R〈/sub〉, and 〈em〉H〈/em〉〈sub〉CI〈/sub〉 decreased with an increase in temperature from cryogenic temperatures to ambient temperatures. The alloy powder was relatively stable up to ~ 600 K. The alloy powders thermally treated at 800 K and 900 K exhibited improved soft-magnetic properties compared to the as-fabricated alloy powder—the 〈em〉M〈/em〉〈sub〉S〈/sub〉 increased by ~ 12% and the 〈em〉H〈/em〉〈sub〉CI〈/sub〉 decreased by ~ 30%.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We investigate the efficacy of polyethylene glycol (PEG) and amine-functionalized MWCNT decorated with MnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 nanocomposites as heating material for magnetic hyperthermia applications. Samples are prepared by a standard solvothermal method. Phase formation of MnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 has been confirmed by X-ray diffractogram and attachment of nanoparticles on the surface of functionalized MWCNT is evident from transmission electron microscopic image of nanocomposite. Fourier transform infrared spectrum of PEG-functionalized MWCNT and amine-functionalized MWCNT confirmed the presence of PEG and amine group, respectively. As desirable for stability in magnetic hyperthermia, vibration sample magnetometer study suggests superparamagnetic behaviour of all the samples at temperatures 300 K, 200 K and 100 K except at 5 K, which is below blocking temperature as confirmed by ZFC–FC curves. Estimated Curie temperature (〈em〉T〈/em〉〈sub〉C〈/sub〉) and room temperature effective anisotropy is found to increase in nanocomposites, highest for amine-functionalized MWCNT/MnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 nanocomposite. A clear correlation between effective anisotropy and heat generation capability (SAR/ILP) has been observed: higher the anisotropy, higher is the heat generation capability (SAR/ILP).〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉A novel nanocomposite coating, containing calcium titanate (CaTiO〈sub〉3〈/sub〉), sodium titanate nanotube (Na-T) and rutile, was prepared on a titanium substrate. At first, calcium phosphate was deposited electrochemically on Ti substrate. Hydrothermal processing at 130 °C in 10 M NaOH transformed calcium phosphate layer into well-crystallized calcium titanium oxide hydroxide (Kassite) and titanium surface into Na-T. Annealing at 350 °C transformed the titanium metal surface into rutile (TiO〈sub〉2〈/sub〉) and the final coating was CaTiO〈sub〉3〈/sub〉/Na-T/rutile composite. Hydrothermal treatment decreases adhesion bond strength and microhardness. Although the adhesion strength of the final coating was comparative to that of the initial coating, hardness and corrosion resistance were increased with annealing at 350 °C due to the formation of buffer layer of rutile phase.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, we have demonstrated UV photodetector based on SnO〈sub〉2〈/sub〉 nanowire (NW) arrays fabricated using a catalytic free and controlled growth process called glancing angle deposition technique. The fabricated SnO〈sub〉2〈/sub〉 NWs were amorphous in nature with highly periodic and perpendicularly oriented structures of length ~ 160 ± 5 nm with ~ 60 ± 5 nm average diameter. The reported Au/SnO〈sub〉2〈/sub〉 NW/n-Si device showed a good rectifying behavior with a rectification ratio of ~ 6 due to the formation of high-quality Schottky contact at the Au/SnO〈sub〉2〈/sub〉 NW interface. The Au/SnO〈sub〉2〈/sub〉 NW/n-Si device exhibited a high responsivity (0.142 A/W) and external quantum efficiency (56.8%) at − 2 V applied bias as compared to the Au/SnO〈sub〉2〈/sub〉 thin-film (TF)/n-Si device. Moreover, the Au/SnO〈sub〉2〈/sub〉 NW/n-Si device attained a high detectivity of 10.8 × 10〈sup〉10〈/sup〉 Jones and noise equivalent power as low as 38.8 × 10〈sup〉−12〈/sup〉 W. The high surface to volume ratio and the enormous amount of photogenerated carriers in case of SnO〈sub〉2〈/sub〉 NW arrays made the Au/SnO〈sub〉2〈/sub〉 NW/n-Si device to exhibit high photosensitivity. Furthermore, on UV illumination, the Au/SnO〈sub〉2〈/sub〉 NW/n-Si detector showed fast device response with a rise time of 0.18 s and a fall time of 0.25 s. The current conduction mechanism in case of Au/SnO〈sub〉2〈/sub〉 NW/n-Si device is explained with respect to device band diagram.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Cadmium sulfide (CdS) nanoparticles were prepared by hydrothermal method at 150 °C under different reaction times. It was found that hydrothermal method is an effective, quick, and eco-friendly method to synthesis CdS nanoparticles of hexagonal structure at lower temperature. X-ray peak profile analysis by Williamson–Hall analysis and size–strain plot was employed to estimate the crystallite size and lattice strain of the synthesized CdS nanoparticles and to investigate their effects on the peak broadening. The values of strain, stress and energy density were determined for all XRD peaks of wurtzite hexagonal phase of CdS, by applying various forms of Williamson–Hall procedure, such as UDM (uniform deformation model), USDM (uniform stress deformation model) and UDEDM (uniform deformation energy density model). The obtained results indicate that the crystallite size of CdS nanoparticles estimated from Scherrer equation, Williamson–Hall plots and size–strain plot, are nearly similar and in the range of 14–37 nm. CdS nanoparticles were also investigated using high-resolution transmission electron microscopy (HR-TEM), Fourier transform infra-red spectroscopy (FT-IR), and UV–visible and fluorescence spectroscopy. A dependence of the band gap and the nanoparticle size on the reaction time was reported.〈/p〉

Beschreibung: 〈span〉 〈h3〉Abstract〈/h3〉 〈p〉A novel hierarchical samarium (Sm)-doped ZnO nanorod–nanosheet architecture with high-temperature ferroelectricity (〈em〉T〈/em〉〈sub〉c〈/sub〉 ~ 110 °C, 〈em〉E〈/em〉〈sub〉c〈/sub〉 ~ 3.64 kV/cm and 〈em〉P〈/em〉〈sub〉r〈/sub〉 ~ 0.08 μC/cm〈sup〉2〈/sup〉) have been developed here using wet chemical co-precipitation method. In this study, we show the origin of ferroelectric behavior in Sm-doped ZnO product and study the effect of frequency and temperature on its dielectric characteristics. Interestingly as an impact of Sm-doping, the morphology of pristine ZnO got evolved from 1D nanopencils (NPCs) to 3D hierarchical architectures composed of both 1D nanorods (NRs) and 2D nanosheets (NSs). Crystallite size (〈em〉L〈/em〉), lattice strain (〈em〉ε〈/em〉), deformation stress (〈em〉σ〈/em〉), and uniform energy density (〈em〉u〈/em〉) of both isolated 1D NPCs and 3D hierarchical NR–NS architectures were evaluated using the Debye–Scherrer and Williamson–Hall methods. Temperature-dependent real dielectric constant (〈em〉ε〈/em〉′) revealed a ferro- to para-electric transition peak at 110 °C. Temperature-dependent complex dielectric constant (〈em〉ε″〈/em〉), dielectric loss (tan 〈em〉δ〈/em〉) and ac conductivity (〈em〉σ〈/em〉) were found to increase with temperature. The frequency-dependent dispersion curves of dielectric properties showed an increase in ac conductivity with increase in frequency whereas complex part of dielectric constant and dielectric loss showed an opposite trend. The Sm-doped ZnO NR–NS architecture exhibits weak ferroelectricity with a coercive field (〈em〉E〈/em〉〈sub〉c〈/sub〉) of 3.64 kV/cm and a remnant polarization (〈em〉P〈/em〉〈sub〉r〈/sub〉) of 0.08 μC/cm〈sup〉2〈/sup〉 at room temperature. Moreover, the high-temperature ferroelectricity established in this work will make Sm–ZnO a futuristic material in the field of designing memory devices.〈/p〉 〈/span〉 〈span〉 〈h3〉Graphical abstract〈/h3〉 〈p〉 〈span〉 〈span〉 〈img alt="" src="https://static-content.springer.com/image/MediaObjects/339_2019_2584_Figa_HTML.png"〉 〈/span〉 〈/span〉 〈/p〉 〈/span〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, MoS〈sub〉2〈/sub〉/PbI〈sub〉2〈/sub〉 heterostructures were synthesized via a two-step synthesis method using vapor deposition and direct water bath heating. Raman spectroscopy and Atomic Force Microscope were used to characterize the MoS〈sub〉2〈/sub〉/PbI〈sub〉2〈/sub〉 heterostructures. The Kelvin probe force microscope was characterized the surface potential of MoS〈sub〉2〈/sub〉/PbI〈sub〉2〈/sub〉 heterostructures. It has shown that the surface potential has undergone a significant change transfer in the interlayer between MoS〈sub〉2〈/sub〉 and PbI〈sub〉2〈/sub〉, which means that at the interface charge transfer occurs and the electrons transfer from MoS〈sub〉2〈/sub〉 to PbI〈sub〉2〈/sub〉. These results provide a theoretical basis for further understanding of the electrical properties of MoS〈sub〉2〈/sub〉/PbI〈sub〉2〈/sub〉 heterostructures.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, the effects of magnetic flux and the width of the quantum ring on plasmon frequency are studied in a narrow quantum ring threaded by magnetic flux. Plasmon frequency is obtained by random phase approximation in the zero wave vector limits. Calculation of plasmon frequency as a function of magnetic flux shows Aharonov–Bohm oscillations. The periodicity and the amplitude of Aharonov–Bohm oscillations depend on magnetic flux and the width of the ring. In other words, the plasmon frequency of the quantum ring is sensitive to the variation of the magnetic flux and when the width is small, the modulation is more sensitive since the period and amplitude are smaller. The absorption coefficient versus ring radius changes from infrared region to ultraviolet region, which it can be of relevant application in solar cells.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉A solid solution of BaMnO〈sub〉3−δ〈/sub〉 and Bi〈sub〉0.5〈/sub〉Na〈sub〉0.5〈/sub〉TiO〈sub〉3〈/sub〉 was prepared using a sol–gel method. X-ray diffraction analysis of Bi〈sub〉0.5〈/sub〉Na〈sub〉0.5〈/sub〉TiO〈sub〉3〈/sub〉 − 〈em〉x〈/em〉 BaMnO〈sub〉3−δ〈/sub〉 samples indicated a rhombohedral structure of Bi〈sub〉0.5〈/sub〉Na〈sub〉0.5〈/sub〉TiO〈sub〉3〈/sub〉 materials during distortion due to the random distribution of Ba and Mn cations in the host lattice. The substitution of Ba and Mn at 〈em〉A〈/em〉- and 〈em〉B〈/em〉-sites in the perovskite structure of Bi〈sub〉0.5〈/sub〉Na〈sub〉0.5〈/sub〉TiO〈sub〉3〈/sub〉 changed the optical band gap due to local defect and/or promotion of oxygen vacancies. The samples exhibited strong room temperature ferromagnetism, which overcame the weak ferromagnetism and diamagnetism of Bi〈sub〉0.5〈/sub〉Na〈sub〉0.5〈/sub〉TiO〈sub〉3〈/sub〉 materials. Our study provided a flexible approach to integrate the ferromagnetism properties of ferroelectric materials.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Magnetron co-sputtering method followed by selenization was used for the preparation of Cu〈sub〉2〈/sub〉Zn(Sn,Ge)(S,Se)〈sub〉4〈/sub〉 (CZTGeSSe) thin film. The impact of Ge doping layer with different sputtering times on crystalline quality, surface roughness, band structure and device performance of CZTGeSSe absorber was systematically investigated. It was found that the increased Ge/(Ge + Sn) ratio could effectively promote the grain growth and improve the band mismatching of CZTGeSSe/CdS interface. The CZTGeSSe thin film with minimum roughness and increased CBO (− 0.54 to − 0.41 eV) was obtained with the increased Ge/(Ge + Sn) ratio of 7.3%. However, oversized grain with rougher surface could result in a non-uniform coverage phenomenon of CdS layer, leading to severe interface recombination. After optimizing the Ge/(Ge + Sn) ratio, the best device performance with an efficiency of 3.19% was achieved in flexible CZTGeSSe thin film solar cells.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Transport measurement techniques are generally considered to be indirect methods of probing the phenomenology of materials and hence are limited in scope and require careful interpretation. However, when performed with due care and precision in addition to other characterization methods, magnetotransport measurements are an essential tool in the study of magnetic and electronic materials particularly in proving potential devices that function on the basis of charge or spin transport. In this work, we demonstrate the advantage of employing a method that simultaneously measures the planar Hall effect and the anisotropic magnetoresistance which are two aspects of the resistivity anisotropy to characterize a range of semiconducting and conducting oxide thin films. The development of novel magnetotransport characterization methods is motivated by the need for reliable measurements of the electronic properties of a wide range of materials under varying thermal, mechanical and magnetic conditions.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉A novel and simple fabrication method was proposed to produce microfluidic channels with various cross-sectional shapes, such as parallelogram, rhombus, pentagon and hexagon. The present study has the advantages of not only fabricating the microfluidic channel shapes that have not been reported before, but also the fabrication process is simple, flexible and robust. Microfluidic channels were fabricated using anisotropic wet etching of Si wafer and self-alignment between Si structure and PDMS mold. In this regard, (100) single crystal Si wafer was used to fabricate the Si microchannel and the master for PDMS mold using photolithography and anisotropic KOH etching. The Si structure for the microchannel and master were formed from the same Si wafer by KOH etching, and the PDMS mold was made from the Si master. Finally, the microchannels with various cross-sectional shapes could be easily formed through self-alignment of the Si microchannel and PDMS mold. They were permanently bonded using O〈sub〉2〈/sub〉 plasma treatment. It is expected that the fabricated microchannel with various cross-sectional shapes can be used in wide fields such as heat transfer, microscale transport of particle and fluid, and particle separation based on inertial focusing. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Transition metal oxide core–shell-nanostructured Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉 is attractive in photocatalytic, optoelectronics and optical applications. Magnetic Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉 core–shell nanocomposites were synthesized by a facile hydrothermal method. Transmission electron microscopy (TEM) results show that the 80-nm-diameter nanoparticles were composed of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 core and MoS〈sub〉2〈/sub〉 shell. The presence of characteristic of Fe–O and Mo–O vibrations in Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉 FT-IR spectra indicate the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 has been composited with MoS〈sub〉2〈/sub〉 successfully. The optical UV–Vis spectra of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉 composites exhibited a strong peak at 250–300 nm due to the strong absorption of MoS〈sub〉2〈/sub〉. The photoluminescence spectra of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉 showed two peaks at 670 and 625 nm corresponding to A1 and B1 excitons of MoS〈sub〉2〈/sub〉. Glass-containing nanoparticles have promising multifunctional advantages such as the simultaneous existence of magnetic, optical and photoluminescence. Glasses containing different Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉 contents were fabricated in this study by melt-quenching method. Glass network was disordered by the doping, and as the doping content increasing, the coordination numbers were changed and more non-bridging oxygen numbers were produced, these modifications on glass structure induced changes of glass properties. Compared to spectra of base glass, the UV–Vis absorption spectra of doped glasses showed a red-shift in cutoff wavelength and an absorption peak around 680 nm due to the excitation of Mo〈sup〉5+〈/sup〉 (4d〈sup〉1〈/sup〉) ions. The photoluminescence spectra of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉-doped glasses present one intense peak centered around 570 nm due to the charge transfer of O〈sup〉2−〈/sup〉→Mo〈sup〉6+〈/sup〉 ions in MoO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 units, and the intensity of this emission peak increased with doping contents. The conductivity of base glass gets increased from 1.59 × 10〈sup〉−7〈/sup〉 to 2.08 × 10〈sup〉−6〈/sup〉 S cm〈sup〉−1〈/sup〉 when the doping content reaches to 5%. Such improvement is mainly caused by the non-adiabatic small polaron hopping at 473 K and non-bridging oxygens production. Glass doped with 5% Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉 exhibited promising photoluminescence, optical cutoff wavelength (526 nm) and high electrical conductivity (2.08 × 10〈sup〉−6〈/sup〉 S cm〈sup〉−1〈/sup〉) due to the charge transfer of Fe and Mo ions and high polarization property of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@MoS〈sub〉2〈/sub〉.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Flexoelectricity offers a number of advantages in micro/nano-scale devices when compared with piezoelectricity as confirmed through numerous experiments and theoretical analyses. Snap-through behavior in bistable plate would convey a higher conversion efficiency for energy harvesting. However, there is no theoretical research on micro/nano-scale energy harvester with flexoelectricity based on bistable plate. This paper describes an electro-thermo-mechanical coupling system of micro/nano-scale bistable plates for piezoelectric energy-harvesting applications. The nonlinear geometric theory of Von Kármán, strain gradient theory, the flexoelectric effect, and Hamilton’s principle were used to derive nonlinear dynamic formulas. The ambient vibration frequency and snap-through behavior both have an effect on the output voltages calculated by Matlab® software. An expression for the energy conversion efficiency of the bistable plate was derived and the influence of resistance on this efficiency was investigated. The result showed that the snap-through behavior delivered a large-amplitude vibration and a higher output voltage at the range of one-third super-harmonic resonance (2.8–3.5 MHz) for the micro/nano-scale bistable plate. This work will be helpful in the design of micro/nano-scale bistable plates with higher output voltages and improved conversion efficiencies for energy harvesting.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Due to the great interest in obtaining solar cells based on graphene/semiconductor Schottky junction and MoS〈sub〉2〈/sub〉/semiconductor heterojunction, in this review, we are presenting the technical details regarding those solar cells. For a better understanding of the technology used in the solar cells mentioned above, we initially show the graphene/semiconductor Schottky junctions and the adaptation of the thermionic theory to this type of junction. After this, we show the graphene/semiconductor Schottky junction solar cells and the MoS〈sub〉2〈/sub〉/semiconductor heterojunction solar cells. It is noteworthy that the understanding of this technology will serve as the basis for studies of more complex nanophotonic solar cells.〈/p〉

Beschreibung: 〈p〉In the original publication of this article the author noticed some important corrections.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, we perform an integration between the tape casting and magnetron sputtering techniques to produce hybrid materials. To this end, trilayered nanostructures of NiFe/Cr/NiFe based on 〈span〉 〈span〉\(\hbox{Al}_{2}\hbox{O}_{3}\)〈/span〉 〈/span〉 flexible sheet are produced by magnetron sputtering deposition. From the well-known dependence of the magnetic properties of NiFe alloy as a function of the thicknesses, here we study samples where the NiFe thicknesses are varied from 105.0 nm up to 142.5 nm, while the Cr layers varied from 15.0 nm up to 90.0 nm. From the structural characterization, a polycrystalline behavior for the 〈span〉 〈span〉\(\hbox{Al}_{2}\hbox{O}_{3}\)〈/span〉 〈/span〉 grains dispersed in an amorphous matrix and a (111) orientation for the NiFe layers are observed. The magnetic characterization reveals the mirroring of the studied trilayered nanostructures concerning the traditional studies for the same thicknesses grown onto rigid (glass) substrate. These results bring these hybrid nanostructures as an attractive candidate for a flexible non-magnetostrictive material to use in smart and nano-functionalized ceramic materials.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉LaBMoO〈sub〉6〈/sub〉:Dy〈sup〉3+〈/sup〉 phosphor is successfully synthesized in the air by the solid-state reaction method. The luminescence properties and crystal structures are researched. LaBMoO〈sub〉6〈/sub〉:Dy〈sup〉3+〈/sup〉 phosphor with excitation at 388, 398, 426, and 451 nm emits yellow light. The emission spectrum of LaBMoO〈sub〉6〈/sub〉:Dy〈sup〉3+〈/sup〉 phosphor in the range of 450–780 nm contains four emission bands peaking at ~ 480, 570, 658, and 750 nm because of the 〈sup〉4〈/sup〉F〈sub〉9/2〈/sub〉 → 〈sup〉6〈/sup〉H〈sub〉15/2〈/sub〉, 〈sup〉6〈/sup〉H〈sub〉13/2〈/sub〉, 〈sup〉6〈/sup〉H〈sub〉11/2〈/sub〉, and 〈sup〉6〈/sup〉H〈sub〉9/2〈/sub〉 transitions of Dy〈sup〉3+〈/sup〉 ion, respectively. The optimal Dy〈sup〉3+〈/sup〉 ion concentration is ~ 6 mol% in LaBMoO〈sub〉6〈/sub〉:Dy〈sup〉3+〈/sup〉 phosphor. The lifetime of LaBMoO〈sub〉6〈/sub〉:Dy〈sup〉3+〈/sup〉 phosphor decreases from 0.467 to 0.279 ms with increasing Dy〈sup〉3+〈/sup〉 ion concentration from 2 to 10 mol%. The energy-level diagram of Dy〈sup〉3+〈/sup〉 ion is used to explain the luminous mechanism of LaBMoO〈sub〉6〈/sub〉:Dy〈sup〉3+〈/sup〉 phosphor. The experimental results indicate a potential application of LaBMoO〈sub〉6〈/sub〉:Dy〈sup〉3+〈/sup〉 phosphor as yellow phosphor for light-emitting diode based on near ultraviolet and blue chips.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉High quality, ~ 120 nm thin ZnO and Ti-doped ZnO (TZO) films were deposited on silicon substrates using magnetron co-sputtering technique. Surface roughness of the films was ~ 2 nm. Ti incorporation effect on the structure, morphology, conductivity, density of states (DOS) and conduction mechanism was investigated in detail. Ti ions were incorporated in the interstitial sites of hexagonal ZnO lattice. Average crystallite size increased from ~ 16.63 to ~ 19.08 nm upon Ti doping in ZnO film. Conduction mechanism changed from overlapping large polaron tunneling (OLPT) for undoped ZnO film to corelated barrier hopping (CBH) for TZO film. The experimental data were fitted theoretically using OLPT and CBH models to calculate frequency and temperature-dependent DOS. An enhancement of ac conductivity and DOS was observed with the doping of Ti in ZnO thin film. Complex modulus study of TZO film revealed transition from long-range mobility to short-range mobility with increase in frequency.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉〈em〉Neoscytalidium〈/em〉 (or 〈em〉N.〈/em〉) 〈em〉dimidiatum〈/em〉 and 〈em〉N. novaehollandiae〈/em〉 are two aggressive plant pathogenic species that affect several agricultural crops. Early detection and identification of these fungi are of critical importance to bring about the effective minimization to the threat they pose to the infected plants. Herein, two species of 〈em〉Neoscytalidium〈/em〉 were rapidly discriminated by utilizing the rRNA internal transcribed (ITS4-5.8S-ITS5) PCR primers. A total of 100 isolates of 〈em〉Neoscytalidium〈/em〉 species, which were isolated from Iraqi canker-infected fig trees, were included in this study. Two discrete electrophoretic PCR bands were observed in 〈em〉Neoscytalidium〈/em〉 isolates—A-variants were about 546 bp, while B-variants were about 993 bp in length. The comprehensive phylogenetic analysis of both DNA variants revealed that A-variants resided between 〈em〉N. novaehollandiae〈/em〉 and 〈em〉N. hyalinum〈/em〉, while B-variants were closely related to 〈em〉N. dimidiatum〈/em〉. Furthermore, the highly specific re-constructed tree of both electrophoretic variants demonstrated that B-variants share a high similarity with 〈em〉N. novaehollandiae〈/em〉. Additionally, the secondary structures for both variants were predicted computationally to reveal the structural patterns that each variant follows. In conclusion, a small rRNA locus comprising 22 nucleotides that differs in the two variants is potentially responsible for this species-specific classification. The main divergence in the amplified loci led to the classification of these fungal variants into two main species, namely 〈em〉N. dimidiatum〈/em〉 and 〈em〉N. novaehollandiae〈/em〉, demonstrating that the amplification by ITS4–ITS5 rRNA fragment is a beneficial strategy that can be employed for the assessment of 〈em〉Neoscytalidium〈/em〉 diversity in the natural ecosystems.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Turkeys and broilers have been identified as important reservoirs for 〈em〉Campylobacter jejuni〈/em〉 which is of public health significance. The evaluation of the genotypes among 〈em〉C〈/em〉. 〈em〉jejuni〈/em〉 strains within different reservoirs is critical for our understanding of the epidemiology of this infectious agent. The present study aimed to compare the genetic diversity and differences of 〈em〉C〈/em〉. 〈em〉jejuni〈/em〉 isolates from turkeys and broilers using flagellin PCR-RFLP typing (〈em〉flaA〈/em〉 typing) technique, in terms of the ease of use and discriminatory power. Sixty 〈em〉C〈/em〉. 〈em〉jejuni〈/em〉 isolates were detected biochemically and confirmed by duplex-PCR from turkeys and broilers (30 strains from each bird species). Then, a 〈em〉flaA〈/em〉 gene fragment (1725 bp) of 〈em〉C〈/em〉. 〈em〉jejuni〈/em〉 isolates was amplified and amplicons were digested with HpyF3I enzyme. Restriction analysis by HpyF3I gave four different 〈em〉flaA〈/em〉 patterns (H1, H2, H3, H4) among all tested 〈em〉C〈/em〉. 〈em〉jejuni〈/em〉 isolates. In broiler isolates, all four patterns were observed but in turkey isolates, only H2 and H4 patterns were present. The results clearly demonstrated that distribution of the 〈em〉flaA〈/em〉 typing patterns differed depending on the host species (broiler/turkey). H1 and H3 〈em〉flaA〈/em〉 types are more prevalent in broiler than turkey isolates, while H2 type is significantly more prevalent within isolates from turkey (〈em〉p〈/em〉 〈 0.05). The 〈em〉flaA〈/em〉 typing technique by digestion with HpyF3I enzyme can almost give us a clue to the source of infection in local outbreaks.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Mixed infections and heteroresistance of 〈em〉Helicobacter pylori〈/em〉 contribute to decreased efficacy of treatments. This study aimed to investigate frequency of clarithromycin heteroresistance and its link with mixed infections, medication history, and disease severity. A total of 40 pairs of 〈em〉H〈/em〉. 〈em〉pylori〈/em〉 strains were isolated from the antrum and corpus of 97 patients. Susceptibility of the strains to clarithromycin was measured by agar dilution method. Site-specific mutations of 〈em〉23S rRNA〈/em〉 at A2143G, A2142G, and A2142C positions were analyzed by PCR and genomic relatedness of pairs of the strains was determined by random amplified polymorphic DNA (RAPD)-PCR. The results showed a prevalence of 35% (14/40) clarithromycin resistance. Diversity of the antrum and corpus isolates in resistance to clarithromycin was detected among 17.5% (7/40) of the patients. Similarly, diversity in MIC value was also detected in two patients infected with the sensitive strains. Significant difference in frequency of resistance was detected among patients with peptic ulcer disease (PUD) (MIC90 32 μg/mL) and severe gastritis (MIC90 16 μg/mL), compared with those who suffered from non-ulcer dyspepsia (NUD) (MIC90 8 μg/mL) and chronic gastritis (MIC90 0.25 μg/mL). MIC values showed 8–32 folds increased levels in the corpus. A2142G, A2143G, and A2142C mutations were detected in three, two, and two patients, respectively, but not observed in 46% of the resistant strains. RAPD-PCR fingerprints showed identical molecular patterns for the isolates of the corpus and antrum in each patient. In conclusion, microevolution of 〈em〉H〈/em〉. 〈em〉pylori〈/em〉 strains during chronic infection, rather than mixed infection, and inappropriate medication appear to be main reasons of treatment failure in adults.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉〈em〉Pediococcus pentosaceus〈/em〉 GS4 (MTCC 12683), a probiotic lactic acid bacterium (LAB), was found to produce bacteriocin in spent culture. Antibacterial and antagonistic potential of this bacteriocin against reference strains of 〈em〉Staphylococcus aureus〈/em〉 (ATCC 25923), 〈em〉Escherichia coli〈/em〉 (ATCC 25922), 〈em〉Pseudomonas aeruginosa〈/em〉 (ATCC 25619), and 〈em〉Listeria monocytogenes〈/em〉 (ATCC 15313) was proven by double-layer and well diffusion methods wherein nisin and ampicillin were used as positive controls. Bacteriocin in supernatant was purified and analyzed by SDS-PAGE, RP-HPLC, and circular dichroism (CD). The physico-chemical properties of purified bacteriocin were characterized being treated at different temperatures (30 to 110 °C), pH (3.0 to 12.0), with different enzymes (α-amylase, pepsin, and lysozyme), and organic solvents (hexane, ethanol, methanol, and acetone) respectively. The molar mass of bacteriocin (named pediocin GS4) was determined as 9.57 kDa. The single peak appears at the retention time of 2.403 with area amounting to 25.02% with nisin as positive control in RP-HPLC. CD analysis reveals that the compound appears to have the helix ratio of 40.2% with no beta sheet. The antibacterial activity of pediocin GS4 was optimum at 50 °C and at pH 5.0 and 7.0. The pediocin GS4 was not denatured by the treatment of amylase and lysozyme but was not active in the presence of organic solvents. This novel bacteriocin thus m ay be useful in food and health care industry.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 and ZnLa〈sub〉0.5〈/sub〉Fe〈sub〉1.5〈/sub〉O〈sub〉4〈/sub〉 zinc ferrites had been prepared by the hydrothermal method. The detection method using in this investigation was X-ray diffraction, scanning electronic microscope, Fourier transformed infrared spectrometer (FTIR), and vibrating sample magnetometer. The results indicated that the samples had spinel structures. This study revealed that the crystallite size, lattice constant, and X-ray density of samples were decreased, while prolonged holding time and increased temperature, whereas the crystallite size was increased with the temperature increasing. Four absorption bands were observed in FTIR spectra and assigned to the corresponding site bonds. The saturation magnetization (〈em〉M〈/em〉〈sub〉S〈/sub〉), coercivity, magnetic moment, and anisotropy constant (〈em〉K〈/em〉) were affected by the holding time and temperature. Anisotropy constant proved dependence on the temperature, and it increased with the enhancement of temperature.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We report on the effects of interactions on the magnetocaloric properties of γ-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles with an average fixed size of 4.7 nm. The influence of particles interaction was investigated by changing their surrounding through the dispersion of γ-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles in polyvinyl alcohol with different concentrations: powder, IN (isolated particle near) and IF (isolated particle far). 〈em〉T〈/em〉〈sub〉B〈/sub〉 decreases from 124 to 21 K with increasing volume fraction of γ-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles in polyvinyl alcohol from powder to IF sample, due to decrease in the magnetic interparticle interactions (dipolar interaction). The temperature dependence of the magnetic entropy change (− Δ〈em〉S〈/em〉〈sub〉M〈/sub〉) was determined using isothermal magnetization. The caret shape of (− Δ〈em〉S〈/em〉〈sub〉M〈/sub〉) curves shows that the magnetic transition near 〈em〉T〈/em〉〈sub〉B〈/sub〉 for all samples was a second-order phase transition. Under a magnetic field change of 10 kOe, the (− Δ〈em〉S〈/em〉〈sub〉M〈/sub〉) and relative cooling power (RCP) decrease from 1.11 to 0.65 J/kg K and 64–23 J/kg when passing from powder to IF samples, respectively. The decrease in the magnetocaloric performance with decreasing the magnetic interparticle interactions was attributed to the decrease of magnetization.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Tungsten trioxide was prepared by a hydrothermal method, and WO〈sub〉3〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite photocatalysts were prepared in two steps by hydrothermal synthesis and muffle furnace calcination. The hydrogen production experiment was carried out using g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and WO〈sub〉3〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composites under simulated visible light irradiation. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), ultraviolet–visible diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR) and Brunauer–Emmett–Teller (BET) analysis. It was found that WO〈sub〉3〈/sub〉(H〈sub〉2〈/sub〉O)〈sub〉0.333〈/sub〉 prepared by hydrothermal treatment is nanorod-like and forms an effective combination with lamellar g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. The hydrogen production rate of the optimal sample is 224.4 μmol/h, which is twice that of pure g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. The addition of tungsten trioxide improves the separation efficiency of photogenerated electron–hole pairs and contributes to the improvement in the photocatalytic performance. This is of great significance to the application of modified g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Upsurge in the instances of antibiotic-resistant uropathogenic 〈em〉Escherichia .coli〈/em〉 (UPECs) strains has repositioned the attention of researchers towards a century old antimicrobial approach popularly known as phage therapy. Rise of extended spectrum beta lactamase (ESBL) and biofilm producing strains has added another step of hurdle in treatment of uropathogens with conventional antibiotics, thus providing a further impetus for search for exploring new therapeutic measures. In this direction, bacteriophages, commonly called phages, are recently being considered as potential alternatives for treatment of UPECs. Phages are the tiniest form of viruses which are ubiquitous in nature and highly specific for their host. This review discusses the possible ways of using natural phages, genetically engineered phages, and phage lytic enzymes (PLEs) as an alternative antimicrobial treatment for urinary tract infections. The review also sheds light on the synergistic use of conventional antibiotics with phages or PLEs for treatment of uropathogens. These methods of using phages and their derivatives, alone or in combination with antibiotics, have proved fruitful so far in in vitro studies. However, in vivo studies are required to make them accessible for human use. The present review is a concerted effort towards putting together all the information available on the subject.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Homeostatic mechanisms preventing the toxicity of heavy metal ions in cells involve, among others, compartmentalization and binding with peptidaceous ligands, particularly the cysteinyl-rich metallothioneins (MTs). We have previously shown that in natural conditions Zn-overaccumulating ectomycorrhizal (EM) fungus 〈em〉Russula bresadolae〈/em〉 stores nearly 40% of Zn bound with cysteinyl- and hystidyl-containing RaZBP peptides, which resemble MTs, while the detoxification of Zn and Cd in EM 〈em〉Hebeloma mesophaeum〈/em〉 relies upon compartmentalization in small vesicles and vacuoles, respectively. Here, we examined the performance of Ra〈em〉ZBP1〈/em〉 gene expressed in 〈em〉H. mesophaeum〈/em〉 mycelium with respect to handling of Zn and Cd. Expression of Ra〈em〉ZBP1〈/em〉 impaired growth of the mycelium on low-Zn medium by 60%, the growth was partly ameliorated upon the addition of Zn and remained considerable up to 2 mmol/L Zn, while the growth of the wild-type and control mycelia transformed with empty T-DNA was severely reduced in the presence of 0.5 mmol/L Zn; furthermore, Ra〈em〉ZBP1〈/em〉 slightly added to Cd tolerance in the range of Cd concentrations of 0.625 to 8 μmol/L. Staining of Zn- or Cd-exposed hyphal cells with Zn- or Cd-specific fluorescent tracers did not indicate that the expression of Ra〈em〉ZBP1〈/em〉 would redirect the flow of the metals away from their innate sinks. Size exclusion chromatography of extracted metal species revealed that the complexes corresponding to Zn/Cd-RaZBP1 are present only in minute levels. Considering that RaZBP1 inhibited growth at low Zn, and despite the benefit that it provided to 〈em〉H. mesophaeum〈/em〉 in the presence of high Zn and moderate Cd, these data indicate that the binding of excess Zn and Cd with RaZBP1 is not a trait that would be outright transmitted to 〈em〉H. mesophaeum〈/em〉.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We have worked out a rapid 1-day test based on photosynthesis measurements to estimate suitable growth temperature of microalgae cultures. To verify the proposed procedure, several microalgae—〈em〉Chlorella〈/em〉, 〈em〉Nostoc〈/em〉, 〈em〉Synechocystis〈/em〉, 〈em〉Scenedesmus〈/em〉, and 〈em〉Cylindrospermum—〈/em〉were cultured under controlled laboratory conditions (irradiance, temperature, mixing, CO〈sub〉2〈/sub〉, and nutrient supply) to find the optima of photosynthetic activity using the range between 15 and 35 °C. These activities were recorded at each temperature step after 2 h of acclimation which should be sufficient as oxygen production and the PQ cycle are regulated by fast processes. Photosynthetic activity was measured using three techniques—oxygen production/respiration, saturating pulse analysis of fluorescence quenching, and fast fluorescence induction kinetics—to estimate the temperature optima which should correspond to high growth rate. We measured all variables that might have been directly related to growth—photosynthetic oxygen evolution, maximum photochemical yield of PSII, 〈em〉F〈/em〉〈sub〉v〈/sub〉/〈em〉F〈/em〉〈sub〉m〈/sub〉, relative electron transport rate rETR〈sub〉max〈/sub〉, and the transients 〈em〉V〈/em〉〈sub〉j〈/sub〉 and 〈em〉V〈/em〉〈sub〉i〈/sub〉 determined by fast fluorescence induction curves. When the temperature optima for photosynthetic activity were verified in growth tests, we found good correlation. For most of tested microalgae strains, temperature around 30 °C was found to be the most suitable at this setting. We concluded that the developed test can be used as a rapid 1-day pre-screening to estimate a suitable growth temperature of microalgae strains before they are cultured in a pilot scale.〈/p〉