ALBERT

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 319〈/p〉 〈p〉Author(s): Subish John, Samba Siva Vadla, Somnath C. Roy〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉CuO is a narrow band gap 〈em〉p〈/em〉-type semiconducting material having a wide range of applications. However, it is quite challenging to obtain phase pure CuO nanostructures grown directly on Cu substrate as most of the synthesis techniques like thermal oxidation results in the formation of additional Cu〈sub〉2〈/sub〉O phase. In this work, we report the growth of CuO nanoflakes without the formation of Cu〈sub〉2〈/sub〉O by a facile two-step synthesis process which consist of electrochemical anodization of Cu foil followed by low-temperature hydrothermal treatment at 100 °C. The phase purity of the sample is confirmed through XRD, XPS, and HRTEM. Further, photocurrent response of the sample is evaluated, and a rapid thermal treatment was used to improve the photo-response without altering the phase and morphology of the CuO nanoflakes. Such a process at 400 °C for 10 s resulted in a high photocurrent density of −4.6 mAcm〈sup〉−2〈/sup〉 (at 0.05 V 〈em〉vs.〈/em〉 RHE under AM 1.5G conditions). Electrochemical impedance spectroscopy and Mott Schottky analysis shows the direct role of rapid thermal treatment in increasing the charge carrier density of the sample.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468619313337-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 319〈/p〉 〈p〉Author(s): Cong Liu, Fenyun Yi, Dong Shu, Weixin Chen, Xiaoping Zhou, Zhenhua Zhu, Ronghua Zeng, Aimei Gao, Chun He, Xia Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three-dimensional N/S co-doped succulent-like hierarchical carbon (3D NS-SHC) is synthesized by carbonization of a supramolecular cluster. In this supramolecular process, potassium citrate can act as a reliable carbon source, while the thiourea as a N/S source and then, two molecules gradually tend to generate a giant “all-in-one” precursor via hydrogen bonding verified by Independent Gradient Model (IGM) calculation. TEM and SEM images show the N/S co-doped carbon holds a novel 3D succulent-like hierarchical structure. For NS-SHC-8:8 sample, element mapping images display the uniform N/S atoms distribution. These distinct features can be related to the supramolecular polymerization which promotes in-situ N/S co-doping homogenously and conduces to build 3D structure. Typically, NS-SHC-8:8 electrode exhibits prominent specific capacitance (258.5 F g〈sup〉−1〈/sup〉 at 0.5 A g〈sup〉−1〈/sup〉) and excellent cycle stability (94.4% after 20000 cycles) in three-electrode system. Furthermore, an assembled quasi-solid state symmetric supercapacitor delivers good energy density (10.2 Wh kg〈sup〉−1〈/sup〉 at 250 W kg〈sup〉−1〈/sup〉) and steady cycle endurance (85.1% after 10000 cycles). These eximious behaviors of NS-SHC-8:8 are mainly attributed to (1) the uniform N/S atoms distribution and their synergistic effect, which brings extra Faradaic reaction to higher specific capacitance, (2) the charming 3D succulent-like hierarchical structure, which serves as a multifunctional reservoir that can accommodate the ion/charge and facilitate their migration to further promote the electrochemical performance. Above mentions suggest that this uniformly heteroatom-modified carbon material produced by supramolecular technique is promising for high-performance energy storage devices.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468619313283-fx1.jpg" width="296" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 319〈/p〉 〈p〉Author(s): Arunprabaharan Subramanian, Mahadeo A. Mahadik, Jin-Woo Park, In Kwon Jeong, Hee-Suk Chung, Hyun Hwi Lee, Sun Hee Choi, Weon-Sik Chae, Jum Suk Jang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we report the surface treatment on Zr〈sup〉4+〈/sup〉/Al〈sup〉3+〈/sup〉 codoped α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 photoanode for high-performance photoelectrochemical water splitting. A high-temperature quenching exhibits the Zr〈sup〉4+〈/sup〉/Al〈sup〉3+〈/sup〉 codoping in α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 photoanode without damaging morphology. The presence of Zr〈sup〉4+〈/sup〉/Al〈sup〉3+〈/sup〉 codoping shows a cathodic shift in onset potential, but lack of increment in photocurrent reveals the major role of passivation and the minimum doping effect of aluminum. Additionally, CoO〈sub〉x〈/sub〉 cocatalyst exhibits increment in photocurrent with the greater cathodic shift in onset potential than the pristine α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanorods. The CoO〈sub〉x〈/sub〉 surface-reworked Zr〈sup〉4+〈/sup〉/Al〈sup〉3+〈/sup〉 codoped α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 photoanode displays the highest photocurrent of 1.5 mA/cm〈sup〉2〈/sup〉 at 1.23 V vs. RHE (76% increment over the pristine α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉) and 0.7 mA/cm〈sup〉2〈/sup〉 at 1.0 V vs. RHE (102% increment over the pristine α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉). The systematic characterization carried out using x-ray diffraction and scanning electron microscopy confirms that after Zr〈sup〉4+〈/sup〉/Al〈sup〉3+〈/sup〉 codoping, and surface treatment, the crystalline structure, and morphology of the photoanodes remains unchanged. X-ray photoelectron spectroscopy confirmed the existence of Zr〈sup〉4+〈/sup〉/Al〈sup〉3+〈/sup〉 codopants in the hematite nanostructure. The electrochemical properties of the photoanode suggest that Al〈sup〉3+〈/sup〉 and Zr〈sup〉4+〈/sup〉 codoping, as well as surface treatment with CoO〈sub〉x〈/sub〉, cocatalyst lowers charge transfer resistance across the FTO/hematite interface, and hematite/electrolyte interface. This designs not only lowers onset potential but also offers the blueprint for the development of an efficient catalyst for solar water oxidation.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉CoO〈sub〉x〈/sub〉 surface-reworked Zr〈sup〉4+〈/sup〉/Al〈sup〉3+〈/sup〉 codoped α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 photoanode displays the 102% increment in PEC performance than pristine α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 at 1.0 V vs. RHE.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468619312927-fx1.jpg" width="471" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Bioorganic & Medicinal Chemistry, Volume 27, Issue 16〈/p〉 〈p〉Author(s): Tao Li, Jing Li, Yang Yang, Yilin Han, Dirong Wu, Tao Xiao, Yang Wang, Ting Liu, Yonglong Zhao, Yongjun Li, Zeqin Dai, Xiaozhong Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The deficiency of nucleos(t)ide analogues (NAs) as anti-hepatitis B virus (HBV) drugs in clinical use is attributable to their insufficient enrichment in liver and non-target organ toxicity. We aimed to develop potent anti-HBV adefovir derivatives with hepatotrophic properties and reduced nephrotoxicity. A series of adefovir mono 〈span〉l〈/span〉-amino acids, mono cholic acid-drug conjugates were designed and synthesized, and their antiviral activity and uptake in rat primary hepatocytes and Na〈sup〉+〈/sup〉-dependent taurocholate co-transporting polypeptide (NTCP)-HEK293 cells were evaluated. We isolated compound 〈strong〉6c〈/strong〉 as the optimal molecular candidate, with the highest antiviral activity (EC〈sub〉50〈/sub〉 0.42 μmol/L, SI 1063.07) and highest cellular uptake in primary hepatocytes and NTCP-HEK293 cells. In-depth mechanistic studies demonstrated that 〈strong〉6c〈/strong〉 exhibited a lower toxicity in HK-2 cells when compared to adefovir dipivoxil (ADV). This is because 〈strong〉6c〈/strong〉 cannot be transported by the human renal organic anion transporter 1 (hOAT1). Furthermore, pharmacokinetic characterization and tissue distribution of 〈strong〉6c〈/strong〉 indicates it has favorable druggability and pharmacokinetic properties. Further docking studies suggested compounds with ursodeoxycholic acid and 〈span〉l〈/span〉-amino acid groups are better at binding to NTCP due to their hydrophilic properties, indicating that 〈strong〉6c〈/strong〉 is a potential candidate as an anti-HBV therapy and therefore merits further investigation.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0968089619309034-ga1.jpg" width="327" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Bioorganic & Medicinal Chemistry, Volume 27, Issue 17〈/p〉 〈p〉Author(s): Bo Hou, Ze Liu, Xiao-Bei Yang, Wen-Fei Zhu, Jin-Yu Li, Liu Yang, Fu-Cai Reng, Yong-Feng Lv, Jiang-Miao Hu, Guo-Yang Liao, Jun Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The stems of 〈em〉Dryopteris crassirhizoma〈/em〉, one of the main components of Lianhua-Qingwen Formula (LQF) was traditionally used for heat-clearing and detoxifying. Dryocrassin 〈strong〉ABBA〈/strong〉 is a key antiviral component in the herbal medicine while the compound is hard to get in large amounts with the features of homologous compounds, polyphenol groups, and low contents. Therefore, the present work aims to seek influenza H7N9 virus inhibitors from natural source by synthesis of dryocrassin 〈strong〉ABBA〈/strong〉 and its analogues. As a result, total synthesis of the compound was achieved in nine steps with an over-all yield of 4.6%. Neuraminidases (NAs) inhibitory activities of the synthesized product and its analogues were evaluated afterward. Comparing with the positive control, OSV (9.6 μM), it was very exciting that dryocrassin 〈strong〉ABBA〈/strong〉 and its analogues (〈strong〉b5〈/strong〉 and 〈strong〉e2〈/strong〉) showed better NAs inhibitory activity against Anhui H7N9 with IC〈sub〉50〈/sub〉 values of 3.6 μM, 2.5 μM and 1.6 μM. For the highly resistant Shanghai N9, these compounds can also show medium inhibitory activities. Docking results indicated the direct interaction of synthesized 3 hits with the key K294 by hydrogen bonds, but no direct interaction of OSV with the key K294 was observed in Shanghai N9. This study suggested that dryocrassin 〈strong〉ABBA〈/strong〉 and its analogues especially 〈strong〉AB〈/strong〉, which consisted of polyphenol groups may have beneficial effects on treating avian influenza H7N9 virus.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Total synthesis of dryocrassin ABBA and analogue structures with potential inhibitory activity against drug-resistant neuraminidases.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0968089619308879-ga1.jpg" width="278" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics, Volume 1867, Issue 9〈/p〉 〈p〉Author(s): 〈/p〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Biomembranes〈/p〉 〈p〉Author(s): Deo R. Singh, Christopher King, Matt Salotto, Kalina Hristova〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉EGFR is a receptor tyrosine kinase that plays a critical role in cell proliferation, differentiation, survival and migration. Its activating ligand, EGF, has long been believed to stabilize the EGFR dimer. Two research studies aimed at quantitative measurements of EGFR dimerization, however, have led to contradicting conclusions and have questioned this view. Given the controversy, here we sought to measure the dimerization of EGFR in the absence and in the presence of saturating EGF concentrations, and to tease out the effect of ligand on dimer stability, using a FRET-based quantitative method. Our measurements show that the dissociation constant is decreased ~150 times due to ligand binding, indicative of significant dimer stabilization. In addition, our measurements demonstrate that EGF binding induces a conformational change in the EGFR dimer.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0005273619301476-ga1.jpg" width="265" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 153〈/p〉 〈p〉Author(s): Ayoub H. Jaafar, N.T. Kemp〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper reports on the first optically tunable graphene oxide memristor device. Modulation of resistive switching memory by light opens the route to new optoelectronic devices that can be switched optically and read electronically. Applications include integrated circuits with memory elements switchable by light and optically reconfigurable and tunable synaptic circuits for neuromorphic computing and brain-inspired, artificial intelligence systems. In this report, planar and vertical structured optical resistive switching memristors based on graphene oxide are reported. The device is switchable by either optical or electronic means, or by a combination of both. In addition the devices exhibit a unique wavelength dependence that produces reversible and irreversible properties depending on whether the irradiation is long or short wavelength light, respectively. For long wavelength light, the reversible photoconductance effect permits short-term dynamic modulation of the resistive switching properties of the light, which has application as short-term memory in neuromorphic computing. In contrast, short wavelength light induces both the reversible photoconductance effect and an irreversible change in the memristance due to reduction of the graphene oxide. This has important application in the fabrication of cloned neural networks with factory defined weights, enabling the fast replication of artificial intelligent chips with pre-trained information.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622319306943-fx1.jpg" width="485" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 3 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochemical and Biophysical Research Communications, Volume 516, Issue 4〈/p〉 〈p〉Author(s): Yanjie Hou, Tian Gong, Jiangtao Zhang, Xi Yang, Yurong Guo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The thinned-young apple polysaccharides from three varieties were obtained by hot water extraction at 88 ̊C for 120 min. The compositional monosaccharides of the three polysaccharides were shown to be the same (xylose, mannose, galactose and glucose) and the molecular weights of the polysaccharides were in the range of 200–300 kDa. Compared with “Qinyang” and “Pinklady”, the polysaccharide from “Jinshiji” had the highest emulsifying capacity. Moreover, the variations in pH and cation ion concentrations had also a significant effect on the emulsifying properties of the extracted polysaccharides. At pH 2.0–4.0, the prepared emulsion had smaller droplet sizes than at higher pH values. Although the emulsion was stable at low concentrations of Na〈sup〉+〈/sup〉 and Ca〈sup〉2+〈/sup〉 ions, high concentrations of Na〈sup〉+〈/sup〉 and Ca〈sup〉2+〈/sup〉 led to significant destabilization of the emulsion. Conclusively, our results demonstrated the potential application of thinned-young apple polysaccharide as a natural polysaccharide emulsifying agent.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics〈/p〉 〈p〉Author(s): Martina Paumann-Page, Rupert Tscheliessnig, Benjamin Sevcnikar, Romy-Sophie Katz, Irene Schwartz, Stefan Hofbauer, Vera Pfanzagl, Paul G. Furtmüller, Christian Obinger〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Human peroxidasin 1 is a multidomain peroxidase situated in the basement membrane. The iron enzyme with covalently bound heme oxidizes bromide to hypobromous acid which facilitates the formation of distinct sulfilimine cross-links in the collagen IV network and therefore contributes to its mechanical stability. Additional to the catalytically active peroxidase domain peroxidasin comprises a leucine rich repeat domain, four Ig domains and a C-terminal von Willebrand factor type C module (VWC). Peroxidasin has been shown to form homotrimers involving two redox-sensitive cysteine residues and to undergo posttranslational C-terminal proteolytic cleavage. The present study on several recombinantly produced truncated peroxidasin variants showed that the VWC is not required for trimer formation whereas the alpha-helical linker region located between the peroxidase domain and the VWC is crucial for trimerization. Our data furthermore implies that peroxidasin oligomerization occurs intracellularly before C-terminal cleavage. For the first time we present overall solution structures of monomeric and trimeric truncated peroxidasin variants which were determined by rotary shadowing combined with transmission electron microscopy and by small-angle X-ray scattering (SAXS). A triangular arrangement of the peroxidase domains to each other within the homotrimer was revealed and this structure was confirmed by a model of trimeric peroxidase domains. Our SAXS data showed that the Ig domains are highly flexible and interact with the peroxidase domain and that within the homotrimer each alpha-helical linker region interacts with the respective adjacent peroxidase domain. The implications of our findings on the structure-function relationship of peroxidasin are discussed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1570963919301219-ga1.jpg" width="240" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 153〈/p〉 〈p〉Author(s): C.M. Ramos-Castillo, M.E. Cifuentes-Quintal, E. Martínez-Guerra, R. de Coss〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Energy gap engineering in graphene nanostructures is one of the most important topics towards development of graphene-based electronics. In this work, based on the density functional theory, the role of the edge magnetism on the size dependence of Kohn-Sham gap and fundamental energy gap for 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msub〉〈mrow〉〈mtext〉C〈/mtext〉〈/mrow〉〈mrow〉〈mn〉6〈/mn〉〈mtext〉nn〈/mtext〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mtext〉H〈/mtext〉〈/mrow〉〈mrow〉〈mn〉6〈/mn〉〈mtext〉n〈/mtext〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈mtext〉n〈/mtext〉〈mo linebreak="badbreak"〉=〈/mo〉〈mn〉2〈/mn〉〈mo linebreak="goodbreak" linebreakstyle="after"〉−〈/mo〉〈mn〉16〈/mn〉〈/mrow〉〈/math〉) hexagonal graphene quantum dots (GQDs) with zigzag edges is studied. We found a transition from a nonmagnetic to an antiferromagnetic state at a certain critical diameter (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"〉〈mrow〉〈mo〉∼〈/mo〉〈/mrow〉〈/math〉 3 nm), characterized by the opening of a Kohn-Sham gap as a consequence of the exchange interaction between localized edge states. Furthermore, the fundamental gap is obtained from the difference between the calculated vertical ionization and electron affinity energies. Such approximation includes relaxation in the exchange correlation potential when the electron is added to the system, which might be useful for GQDs transport properties interpretation. We found a scaling rule for the fundamental gap dependence on quantum dot size, providing a practical way to predict this property for large GQDs with zigzag edges, which currently in most demanding approaches, such as GW, is unfeasible.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622319306876-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 The International Journal of Biochemistry & Cell Biology, Volume 114〈/p〉 〈p〉Author(s): Deep Pooja, Anusha Gunukula, Nitin Gupta, David J. Adams, Hitesh Kulhari〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The biggest challenge in delivering anticancer agents is the ability to direct these molecules specifically to cancer cells. With this in mind, modern research is focussing on improving the precision of cancer drug delivery by incorporating a ligand that has the ability to specifically recognize cancer cells. Peptides are emerging as a new tool in drug and gene delivery. Peptide-drug conjugates, peptide-modified drug delivery systems, and peptide-coupled imaging agents have been shown to increase on-site delivery. This has allowed better tumor mass contouring in imaging and increased therapeutic efficacy of chemotherapies, reducing adverse effects. Benefits of peptide ligands include their small size, easy and affordable production, high specificity and remarkable flexibility regarding their sequence and conjugation possibilities. Bombesin (Bn) receptors have shown great promise for tumor targeting due to their increased expression in a variety of human cancers, including prostate, breast, small cell lung, and pancreatic cells. This review discusses the overexpression of Bn receptors in different cancers and various approaches to target these receptors for therapeutic and diagnostic interventions in human malignancies.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Physics and Chemistry of Solids, Volume 135〈/p〉 〈p〉Author(s): Lamya H. Al-Wahaibi, Yusuf Sert, Fatih Ucun, Nora H. Al-Shaalan, Aisha Alsfouk, Ali A. El-Emam, Mustafa Karakaya〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This research relates to the molecular structure, electronic properties and IR, Raman and XPS analyses of the potential chemotherapeutic agent namely, 5-(adamantan-1-yl)-〈em〉N〈/em〉-methyl-1,3,4-thiadiazol-2-amine. Another purpose is to explore the structural stabilities and consistencies and, to assess the stable interaction energy and intermolecular hydrogen bond geometry for its dimeric structure. The monomer and dimer optimizations of the molecule have been calculated by the DFT method using various functionals such as B3LYP, B3PW91, mPW1PW91 and M06-2X. Although the minimum energy optimization was calculated at the B3LYP functional, the BSSE-corrected and uncorrected interaction energies of the dimer structure were more effectively obtained with the M062X functional. This assured us a test of the efficiency of M06-Class functional calculations on intermolecular interactions of strongly bound systems. Additionally, the molecular docking study was done between our molecule (ligand) and the previously studied and known as cortisone reductase 11β-Hydroxysteroid dehydrogenase type 1 (receptor, 11-β-HSD1: PDB-2ILT).〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0022369718334346-fx1.jpg" width="455" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Physics and Chemistry of Solids, Volume 135〈/p〉 〈p〉Author(s): Hongfang Jiu, Na Ren, Lixin Zhang, Qing Zhang, Yuying Gao, Yajuan Meng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The flower-like ZnMn〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 hollow microtubules were synthesized by a hydrothermal method and calcination method. The composition and morphology were characterized. The results showed that flower-like hollow microtubules were obtained through calcination treatment. The as-prepared ZnMn〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 electrochemical properties of flower-like hollow microtubules anode material for lithium-ion batteries were investigated. The first charge and discharge capacity was measured at 2152/1263 mA h g〈sup〉−1〈/sup〉 when the current density at 400 mA g〈sup〉−1〈/sup〉. After 300 cycles, the capacity kept 515 mA h g〈sup〉−1〈/sup〉 corresponding to the coulombic efficiency of 99%, which exhibited preferable cycling performance. The stability of the structure has been shown by rate performance, which had been tested under different current density. The results suggest a promising application of the ZnMn〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 as anode material for lithium-ion batteries.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0022369718333468-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Physics and Chemistry of Solids, Volume 135〈/p〉 〈p〉Author(s): Takahiro Iijima, Tadashi Shimizu, Atsushi Goto, Kenzo Deguchi, Toshihito Nakai, Ryutaro Ohashi, Masayoshi Saito〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In Ti-based Ziegler-Natta catalysts (ZNCs), disagreements exist concerning which lateral surface of the MgCl〈sub〉2〈/sub〉 support adsorbs Ti species so as to be an active site for the catalysis of polymerization. In the present paper, we investigated the local structure of TiCl〈sub〉4〈/sub〉 adsorbed onto the surface of MgCl〈sub〉2〈/sub〉 by 〈sup〉47,49〈/sup〉Ti solid-state nuclear magnetic resonance (NMR) spectra at 21.8 T along with density functional theory (DFT) calculations. The magic-angle-spinning NMR spectrum of the TiCl〈sub〉4〈/sub〉/MgCl〈sub〉2〈/sub〉 adduct sample prepared by 20 h of milling, which exhibited broadened and shifted peaks compared to that of the sample without milling, was simulated by a Czjzek model considering the distribution of quadrupole interaction parameters. The electric field gradient and chemical shielding tensors of 〈sup〉49〈/sup〉Ti were obtained via DFT calculations for model molecules of TiCl〈sub〉4〈/sub〉, 2TiCl〈sub〉4〈/sub〉, and Ti〈sub〉2〈/sub〉Cl〈sub〉8〈/sub〉 adsorbed onto the (110), (104), and (104)-step defect surfaces of MgCl〈sub〉2〈/sub〉. By comparing the obtained NMR parameters, the 〈sup〉47,49〈/sup〉Ti NMR spectrum of the milled sample was assigned to TiCl〈sub〉4〈/sub〉 adsorbed onto the (104) surface of MgCl〈sub〉2〈/sub〉, which may not be a principal component of adsorption.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S002236971930472X-fx1.jpg" width="380" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Chromatography B, Volume 1125〈/p〉 〈p〉Author(s): Roberta Natália Cestari, Adriana Rocha, Renê Donizeti Ribeiro de Oliveira, Vera Lucia Lanchote〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gemfibrozil (GFZ) is a derivative of fibric acid and is used in the treatment of dyslipidemia. GFZ may affect the metabolism of various drugs, including statins, by inhibiting the sinusoidal influx transporter OATP1B1 and also CYP2C9 and CYP2C8 enzymes. This study presents the development and validation of a rapid, simple, sensitive and reproducible method of GFZ analysis in human plasma using UPLC-MS/MS. The method was applied in a pharmacokinetic study following administration of multiple doses of 600 mg GFZ every 12 h in healthy volunteers (〈em〉n〈/em〉 = 15). GFZ was separated on a C18 column using a mixture of 0.01% formic acid and acetonitrile (40:60, v/v) as the mobile phase at a flow rate of 0.4 mL/min. The method showed linearity in the range from 0.01 μg/mL to 100 μg/mL plasma. The coefficients of variation and the relative standard errors of the accuracy and precision analyses were 〈15%. The method allowed quantification of plasma concentrations of GFZ in the dose interval of the sixth day of administration of multiple oral doses of GFZ every 12 h. The pharmacokinetic parameters are presented as mean (95% CI): area under the plasma concentration 〈em〉versus〈/em〉 time curve 〈strong〉88.84〈/strong〉 (72.72–104.96) μg·h/mL, steady state mean plasma concentration 7.40 (6.06–8.75) μg/mL, minimum plasma concentration 1.24 (0.87–1.61) μg/mL, maximum plasma concentration 26.73 (21.31–32.15) μg/mL, time to reach maximum plasma concentration 2.28 (1.42–3.13) h, elimination half-life 2.81 (2.22–3.40) h, apparent total clearance 7.72 (5.85–9.58) L/h, apparent distribution volume 33.97 (18.41–49.53) L. In conclusion, the method for analysis of GFZ in human plasma showed sensitivity, linearity, precision and accuracy compatible with application in pharmacokinetic studies of multiple oral dose of 600 mg GFZ every 12 h.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Chromatography A〈/p〉 〈p〉Author(s): Jonas Henschel, Simon Wiemers-Meyer, Marcel Diehl, Constantin Lürenbaum, Wen Jiang, Martin Winter, Sascha Nowak〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The expansion of lithium ion battery (LIB) application is accompanied by the growth of battery pack sizes. This progression emphasizes the consideration of electrolyte safety as well as environmental aspects in case of abuse, accident, or recycling. Hexafluorophosphate is one of the most commonly used conducting salt anions in electrolytes. It has great potential to degrade to various acidic and non-acidic organo(fluoro)phosphates with presence of water and during battery cell operation. Consequently, toxicological investigation on these organo(fluoro)phosphates has emerged because they either have structural similarities as chemical warfare agents or play a widespread physiological role as phosphates in the human body. This circumstance underlines the need of isolated examination of these compounds for safety assessment. In this work, we used hydrophilic interaction liquid chromatography for the extraction of acidic organofluorophosphates from thermally aged LIB electrolytes. The developed two-step fractionation method provided high separation selectivity towards acidic head groups, which allowed the separation of undesired matrix and target compounds. These findings facilitate isolated toxicological investigations on organofluorophosphates that are beneficial for environmental and safety research, the battery cell industry, and human safety surveillance in regard to aged LIB electrolytes.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Shuai Zhao, Wanfen Pu, Mikhail A. Varfolomeev, Chengdong Yuan, Shan Qin, Liangliang Wang, Dmitrii A. Emelianov, Artashes A. Khachatrian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Because the thermal release correlates directly with the success of in-situ combustion (ISC) technology, this research performs a series of investigations concerning thermal behavior and kinetics of heavy crude oil during combustion using high pressure differential scanning calorimetry (HP-DSC) and accelerating rate calorimetry (ARC). The results obtained from HP-DSC profiles indicated that for oil alone and its mixtures with quartz sand/crushed core, the peak temperature was lowered, and the heat flow increased with increasing oxygen partial pressure. The heat enthalpy of low temperature oxidation (LTO) was higher than that of high temperature oxidation (HTO) under oxygen partial pressures of 0.5, 1 and 1.5 MPa, and the increase in heat enthalpy of LTO with oxygen partial pressure was more pronounced than that of HTO. Unlike the crushed core, the addition of quartz sand delayed exothermic oxidation reactions. Compared with oil only and oil + quartz sand, the LTO and HTO peak temperatures of oil + crushed core were considerably lowered, and the effect of crushed core on increasing heat release for LTO at oxygen partial pressure of 1.5 MPa was more prominent. It was observed that the heat enthalpy of LTO and HTO increased quasi-linearly with the oxygen partial pressure in both the presence and absence of quartz sand/crushed core. ISC might be considered as an appropriate candidate for Jiqi block, based on exothermic continuity of the ARC curves, with the near-wellbore zone of target block heated to 180 °C where the exothermic oxidation activity is notably intensified. The kinetic results showed that the LTO and HTO intervals were divided into 6 and 2 subintervals, respectively, which facilitated more precise modelling of the ISC process.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Zan Chen, Menglu Lin, Shuhua Wang, Shengnan Chen, Linsong Cheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Studies have shown that the gas huff and puff injection potentially perform better than the continuous gas flooding in enhancing the hydrocarbon recovery in the liquid rich tight reservoirs. During the fracturing stimulation, only part of the induced hydraulic fractures is propped because proppants cannot be carried to the fracture tips. Moreover, some secondary and tertiary fractures may be too narrow to accommodate any proppants. The conductivity of the unpropped fractures is highly dependent on the variation of the in-situ pressure and may be open and close periodically during the huff-n-puff cycles. In this study, the stress-dependent fracture conductivity and its impact on the produced gas huff-n-puff performance are investigated in a liquid rich tight reservoir, considering the existence of the large amount of the unpropped fractures. The experimental data of stress-dependent fracture conductivity is employed first to simulate the dynamic conductivity during the depletion and the gas huff and puff cycles. A reservoir model is then constructed and history-matched based on the reservoir fluid samples and the field production data collected from the Montney liquid rich tight reservoir in Western Canada. Performance of the produced gas huff-n-puff is examined in the targeted reservoir and results show that contributions of the unpropped fractures cannot be ignored, which leads to 7.8% more condensate (i.e., oil) production and 2.8% higher in barrel of oil equivalent (BOE), compared to the case with propped fractures only. The effects of complex fracture geometry and the cluster completion are also investigated and results show that the unpropped fracture contributions towards the condensate production and BOE are even more pronounced in the complicated scenarios. The condensate oil and BOE are 42.0% and 22.9% higher in complex fracture geometry case and 12.4% and 5.6% higher in the fractures with multiple clusters than those scenarios with propped fractures only. This paper provides a better understanding on the potential performance of enhanced hydrocarbons recovery in liquid rich tight gas reservoirs via gas huff-n-puff operations.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Abdelrahman Elkhateeb, Reza Rezaee, Ali Kadkhodaie〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Traditionally, prediction of facies and permeability for a reservoir rock was one of many challenges in the industry that necessitates advanced and sophisticated evaluation for effective reservoir description. Three wells have been studied in the Perth Basin in Western Australia across the shaly sand of the Irwin River Coal Measures Formation, which contain a comprehensive suite of advanced and conventional logs. Due to the reservoir heterogeneity and the clay distribution, it is very challenging to resolve the effective pore volume, the reservoir facies and how the high permeability zones are distributed within the formation.〈/p〉 〈p〉In this paper, a new technique has been successfully tested on the Shaly Sand by integrating the nuclear magnetic resonance (NMR) and the conventional density log. The method allows the establishment of high-resolution facies classification for the reservoir using an Equivalent Flow Zone Indicator Index (EFZI). The studied core facies have been integrated with the EFZI into a new workflow to distribute facies on a larger scale in the uncored wells.〈/p〉 〈p〉Four hydraulic flow units (HFU) have been defined from one cored well using Flow Zone Indicator approach, with each has a unique FZI value and different permeability model based on core measurements. The EFZI-based high-resolution facies have been validated at several formation depths using the core thin sections to ensure the best calibration will be obtained for facies log, hence the permeability log-to-core match.〈/p〉 〈p〉The methodology will help running an advanced petrophysical analysis for the zone of interest and will reduce the parameters uncertainty. Application of this methodology in the uncored wells has shown very encouraging results, which is believed it can be used in the absence of any core data to resolve the rock typing from the well logs.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Atousa Heydari, Kiana Peyvandi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, the stainless steel mesh was used to study the effect of metallic porous media on the formation of methane hydrate and some parameters such as induction time, the kinetics growth and the mole of gas consumed have been investigated at a temperature of 3 °C (276.15 K) and a pressure of 760 psi (5.24Mpa). The metallic porous media was able to show better results on the methane hydrate formation relative to the silica gel. Hence the induction time and, eventually, the total time of the hydrate formation process decreased by about 60%. The kinetics growth and the amount of gas consumed increased significantly. Also, the effect of two types of anionic and nonionic surfactants as kinetics promoters studied in this porous media. The result of adding SDS and SDBS at a concentration near the CMC designated that the induction time lasted nearly zero and the total time of the process by SDBS was minimal. It should be noted that the non-ionic surfactant SPAN 80 could not have a positive effect on this porous media. In general, therefore, the results of this research attempts to show that the stainless steel mesh with SDBS possessed high potential in obtaining the industrial purpose of gas hydrate growth and also was significant in the field of energy storage and transport.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0920410519306473-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Shuaishuai Jiang, Xuehua Chen, Yingkai Qi, Wei Jiang, Jie Zhang, Zhenhua He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The frequency-dependent attenuation and velocity dispersion of seismic responses are closely related to hydrocarbon reservoirs. To further investigate the characteristics of seismic responses caused by pore fluid-bearing reservoirs, the role of gas saturation is analyzed in seismic responses of sand reservoirs characterized by the patchy saturation model. To this end, a novel wave extrapolation method is developed based on the diffusive-viscous wave equation (DVWE) as well as a scheme for an extended local Rytov Fourier (ELRF) approximation within the extrapolation depth interval. Our proposed method considers the presence of fluid mixtures in the porous media, resulting in seismic attenuation and dispersion by the mechanism generally known as wave-induced fluid flow (WIFF). This method enables an accommodation for the lateral variations in slowness, diffusion coefficient and viscosity. Subsequently, the extrapolation is adopted to model the synthetic seismic data of a distributary channel model. During this modeling, a gas-water saturated sand reservoir embedded into one of the channels was used to comparatively analyze the distinct features on its seismic synthetic data. We exhibited the numerical simulation results using the proposed wave extrapolation method here and the traditional acoustic wave equation (AWE) method. A comparison of the simulation results, demonstrates that our proposed numerical method can depict the seismic dispersion and frequency-dependent attenuation as well as the phase delay effects associated with gas-water-saturated sand reservoirs. Furthermore, we compare the seismic responses by changing the gas saturations of the sand reservoir. The gas saturation of the reservoir has significant effects on the seismic characteristics of the numerical modeling data. The numerical modeling method improves our understanding of the mechanisms of seismic frequency-dependent characteristics associated with gas saturations and potentially contributes to better insights into gas reservoir indicators derived from seismic field data.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Tetrahedron Letters, Volume 60, Issue 33〈/p〉 〈p〉Author(s): Mitali Mishra, Seetaram Mohapatra, Nilima Priyadarsini Mishra, Bighnanshu K. Jena, Pravati Panda, Sabita Nayak〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Heterocyclic compounds particularly five, six and seven membered ring containing heterocycles are the most abundant which constitute a staggeringly diverse and important class of molecules that occur ubiquitously in a variety of synthetic drugs, bioactive natural products, pharmaceuticals and agrochemicals. Owing to the glorious past and impressive present of the biologically active heterocyclic scaffolds, these skeletons have long been a subject of immense interest. Hence, substantial efforts have been made to the development of new and innovative synthetic strategies for the synthesis of these heterocycles involving use of different metal catalysts, organic and inorganic reagents etc. Among the different types of metal catalysts used, iron catalysts are one of the cheap and easily available. In recent time, several new and innovative iron(III) chloride catalyzed synthesis of heterocycles with structural diversity are coming in the forefront of the literature by the scientific community. This review highlights the advancements made so far by iron(III) chloride for the synthesis of different assemblies of small heterocycles covering the year 2014–2018.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0040403919306628-ga1.jpg" width="261" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Hiral D. Shah, J.A. Bhalodia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this communication, we report the structural and electrical transport properties of (1-〈em〉x〈/em〉) La〈sub〉0.7〈/sub〉Sr〈sub〉0.3〈/sub〉Mn〈sub〉0.95〈/sub〉Co〈sub〉0.05〈/sub〉O〈sub〉3〈/sub〉 (LSMCO) + (〈em〉x〈/em〉) ZnO (〈em〉x〈/em〉 = 0%, 6%, 9%, 12%, 15% & 18%) composites. For the preparation of (1-〈em〉x〈/em〉) LSMCO + (〈em〉x〈/em〉) ZnO (〈em〉x〈/em〉 = 6%, 9%, 12%, 15% & 18%) composites, sample of LSMCO was prepared by the auto combustion technique/inexpensive modified sol-gel technique. The results of Rietveld refined XRD data show that LSMCO sample possesses a rhombohedral structure with the 〈em〉R-3c〈/em〉 space group whereas ZnO compound remains with hexagonal structure with the 〈em〉P6〈/em〉〈sub〉〈em〉3〈/em〉〈/sub〉〈em〉mc〈/em〉 space group in all the composite samples. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that no any extra unwanted phase was observed in each composite excluding the LSMCO and ZnO phases. ZnO is mostly distributed at the grain boundaries and on the surface of the LSMCO grains. Elemental presence and ratio was confirmed through the EDX analysis. The electrical resistivity of LSMCO and each composite was measured in the temperature range of 2 K–320 K at 0 Oe, 10 kOe, 50 kOe & 90 kOe magnetic field. The results indicate that the ZnO addition increases the resistivity of all the composites compare to that of pure LSMCO. The electrical resistivity explored by the theoretical model below 〈em〉T〈/em〉〈sub〉MI〈/sub〉 and fitting enlightenment for the observed behavior is transmitted here in detail.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Dezhi Yang, Weihua Liu, Dingfu Cheng, Jieshi Chen, Hao Lu, Chun Yu, Jijin Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉(Co, Cr)23C6 type carbide is a typical metallic compound in many cobalt bearing alloys, and it acts as the strengthening phase in the form of bulk eutectic carbides or precipitated carbides. In this work, first-principles calculations were carried out to investigate the electronic structure, phase stability, mechanical and magnetic properties of (Co, Cr)23C6 with different cobalt occupation. Some of the calculated values are compared with previous studies and, they are found to be in a good agreement. The method considering curvature radius is firstly used to describe the degree of anisotropy. The hardness calculated through elastic constants presents an approximate downtrend with the cobalt concentration. Analysis of the density of states (DOS), overlapped population and electron density maps, indicates that the bonds in (Co, Cr)23C6 are the mixture of covalent, ionic and metallic bonds, the interactions of 〈em〉d-d〈/em〉 orbits between metallic atoms contribute most to the hybridization mode. According to the population analysis, the reduction in hardness can attribute to the increase of metallicity and iconicity of the interacted metallic atoms. In addition, the formation of a large quantity of antibonding also plays a negative role in intrinsic hardness of (Co, Cr)23C6 when massive substitution of cobalt atom.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 804〈/p〉 〈p〉Author(s): Morteza Alizadeh, Andisheh Shakery, Erfan Salahinejad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this research, the structure and mechanical properties of 1050 aluminum strips reinforced with E-glass fibers, processed by the cross accumulative roll bonding (CARB) process, were investigated from microscopic, hardness, tensile and peeling viewpoints. The results indicated that the incorporation of the glass fibers in the Al matrix increases strength and micro-hardness but decreases elongation. In addition, it was realized that some of these fibers are broken and changed to short fibers during the CARB process. The presence of the glass fibers strongly also reduces the bond efficiency of the Al strips, typically from 50% to 5%. To compensate this deleterious effect, it was found that at least 25% should be increased to the normal thickness reduction used in CRAB.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 European Journal of Operational Research〈/p〉 〈p〉Author(s): K.T. Huynh〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We are interested in the stochastic modeling of a condition-based maintained system subject to continuous deterioration and maintenance actions such as inspection, partial repair and replacement. The partial repair is assumed dependent on the past in the sense that it cannot bring the system back into a deterioration state better than the one reached at the last repair. Such a past-dependency can affect (〈em〉i〈/em〉) the selection of a type of maintenance actions, (〈em〉ii〈/em〉) the maintenance duration, (〈em〉iii〈/em〉) the deterioration level after a maintenance, and (〈em〉iv〈/em〉) the restarting system deterioration behavior. In this paper, all these effects are jointly considered in an unifying condition-based maintenance model on the basis of restarting deterioration states randomly sampled from a probability distribution truncated by the deterioration levels just before a current repair and just after the last repair/replacement. Using results from the semi-regenerative theory, the long-run maintenance cost rate is analytically derived. Numerous sensitivity studies illustrate the impacts of past-dependent partial repairs on the economic performance of the considered condition-based maintained system.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 319〈/p〉 〈p〉Author(s): Jeonghoon Han, Changwoo Bae, Songhwa Chae, Dukhyun Choi, Sangmin Lee, Youngsuk Nam, Choongyeop Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Here we introduce the new approach to high-efficiency power generation from a salinity difference using conventional nanoporous Nafion membrane. When access areas on each side of nanoporous Nafion membrane are set to be asymmetric, the ratio of ionic current upon a voltage bias of the different polarity also becomes asymmetric, resulting in ionic diode phenomena. When this geometrical ionic diode effect is combined with a salinity gradient, it can help significantly improve the energy conversion efficiency from a salinity difference even under a hyper-saline environment with a large salinity difference, e.g. ∼41% conversion efficiency and ∼120 nW power generation with 1 M KCl and 1000-fold salinity difference, both of which are comparable with the best performances reported in the previous studies. We propose that the decrease in ion concentration polarization at a low salt concentration side is responsible for the enhanced power generation with the membrane having asymmetric access areas. Our approach is simple to implement and can be applicable to any nanoporous membrane to enhance the power generation from a salinity difference.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 319〈/p〉 〈p〉Author(s): Jialun Chen, Ping Tong, Lingting Huang, Zhonghua Yu, Dianping Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An interdigitated capacitance immunosensing system based enzymatic biocatalytic precipitation on micro-comb electrode was designed for the sensitive detection of prostate-specific antigen (PSA) by coupling Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 MXenes with tyramine signal amplification strategy. The immunosensor was prepared by immobilizing anti-PSA capture antibody on MXenes-coated interdigitated electrode, whereas gold nanoparticles heavily functionalized with horseradish peroxidase (HRP) and detection antibody were utilized as the signal-transducer tags. Introduction of interdigitated electrode was expected to enhance the sensitivity of capacitance immunosensor. This system mainly consisted of the sandwich-type immunoreaction, formation of tyramine-HRP repeats on gold nanoparticle and enzymatic biocatalytic precipitation. The concatenated HRP through the tyramine oxidized numerous 4-chloro-1-naphthol molecules into insoluble benzo-4-chlorohexadienone with the help of H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉, and coated the modified immunosensor to keep free ions away from the electrode, thus causing the local alteration in the capacitance. Under optimum conditions, the change of the immunosensor in the capacitance increased with the increasing target PSA concentrations from 0.1 ng mL〈sup〉−1〈/sup〉 to 50 ng mL〈sup〉−1〈/sup〉 at a detection limit of 0.031 ng mL〈sup〉−1〈/sup〉. Moreover, the interdigitated capacitance immunosensor showed good reproducibility, high specificity and acceptable accuracy for the analysis of human serum specimens in comparison with those obtained from commercial human PSA ELISA kit. Importantly, Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 MXenes-based interdigitated capacitance transducer open new opportunities for protein diagnostics and biosecurity.〈/p〉〈/div〉 〈/div〉