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  • 1
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    Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-08-31
    Description: There is a growing interest in monitoring microplastics in the environment, corresponding to increased public concerns regarding their potential adverse effects on ecosystems. Monitoring microplastics in the environment is difficult due to the complex matrices that can prevent reliable analysis if samples are not properly prepared first. Unfortunately, sample preparation methods are not yet standardized, and the various efforts to validate them overlook key aspects. The goal of this study was to develop a sample preparation method for wastewater samples, which removes natural organic matter without altering the properties of microplastics. Three protocols, based on KOH, H2O2, and Fenton reactions, were chosen out of ten protocols after a literature review and pre-experiments. In order to investigate the effects of these reagents on seven polymers (PS, PE, PET, PP, PA, PVC, and PLA), this study employed µFTIR, laser diffraction-based particle size analysis, as well as TD-Pyr-GC/MS. Furthermore, the study discussed issues and inconsistencies with the Fenton reactions reported in the literature in previous validation efforts. The findings of this study suggest that both H2O2 and Fenton reactions are most effective in terms of organic matter removal from microplastic samples while not affecting the tested polymers, whereas KOH dissolved most PLA and PET particles.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Molecular Diversity Preservation International
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  • 2
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    Nanoemulgel for Improved Topical Delivery of Retinyl Palmitate: Formulation Design and Stability Evaluation (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-04-28
    Description: Retinyl palmitate is a vitamin A ester belonging to the family of endogenous natural retinoid and used to treat various skin disorders like acne, skin aging, wrinkles, and dark spots, as well as to protect against psoriasis. Despite the known therapeutic benefits of retinyl palmitate, the conventional topical delivery of retinyl palmitate commonly associated with adverse reactions such as skin irritation, redness, excessive peeling, and dryness. Therefore, the current study aims to encapsulate the retinyl palmitate in nanoemulsion then incorporate it into a hydrogel system to improve the topical delivery and stability. Low-energy emulsification method was used for the nano-encapsulation of retinyl palmitate. The phase behavior study was used for the investigation and the optimization of the formulation. The droplet size of the optimized nanoemulsion was in nano dimension (16.71 nm) with low polydispersity index (PdI) (0.015), negative zeta potential (−20.6 mV). It demonstrated the influence of vortexing on droplet size and PdI during nanoemulsion preparation. The retinyl palmitate loaded nanoemulgel delivery system exhibited significant improvement (p 〈 0.05) in skin permeability after topical application. Employment of the nano-encapsulation approach afterward dispersion into hydrogel system for the development of a topical delivery system of retinyl palmitate resulted in improvement in its UV and storage stability as well.
    Electronic ISSN: 2079-4991
    Topics: Physics
    Published by Molecular Diversity Preservation International
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  • 3
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    Adsorption of Azo Dye Methyl Orange from Aqueous Solutions Using Alkali-Activated Polypyrrole-Based Graphene Oxide (2019)
    Molecular Diversity Preservation International
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    Publication Date: 2019-10-13
    Description: The adsorption of methyl orange (MO) from aqueous solutions onto a KOH-activated polypyrrole-based adsorbent (PACK) was investigated using batch and fixed-bed column techniques. The structural, thermal, and morphological properties of the PACK, analyzed by various methods, support its applicability as an adsorbent. An adsorption kinetic study revealed a preferably pseudo-second-order (R2 = 0.9996) and rate-limiting step controlled by both film and intra-particle diffusions. The thermodynamic adsorption tests resulted in negative ΔG°, ΔH°, and ΔS° values, which decreased as the temperature and concentration increased, indicating the spontaneous and exothermic adsorption over 25–45 °C. The adsorption isotherms fit the experimental data in the order of Langmuir ≈ Freundlich 〉 Temkin, with evidence of adsorption operating well via the monolayer physical adsorption process, and maximum monolayer adsorption ranging from 520.8 to 497.5 mg/g. The breakthrough curve of the fixed-bed column experiment was modeled using the Thomas, Yoon–Nelson, and Hill models, resulting in an equilibrium capacity of 57.21 mg/g. A 73% MO recovery was achieved, indicating the possibility of column regeneration. Compared to other adsorbents reported, PACK had comparable or even superior capacity toward MO. For cost-effectiveness, similar nitrogen-containing polymeric wastes could be exploited to obtain such excellent materials for various applications.
    Electronic ISSN: 1420-3049
    Topics: Chemistry and Pharmacology
    Published by Molecular Diversity Preservation International
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  • 4
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    Granular Calcite Stimulates Natural Mycorrhization and Growth of White Spruce Seedlings in Peat-Based Substrates in Forest Nursery (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-07-21
    Description: The acidity of peat-based substrates used in forest nurseries limits seedling mineral nutrition and growth as well as the activity of microorganisms. To our knowledge, no study has yet evaluated the use of granular calcite as a covering material to increase pH, calcium and CO2 concentrations in the rhizosphere and ectomycorrhizal development. The objective is to compare different covering treatments on early colonization of the roots by ectomycorrhizal fungi, as well as the growth and calcium nutrition of white spruce seedlings in the forest nursery. Three treatments were used to cover the plant cavities (Silica (29 g/cavity; control treatment), Calcite (24 g/cavity) and calcite+ (31 g/cavity)) and were distributed randomly inside each of the five complete blocks of the experimental design. The results show that calcite stimulates natural mycorrhization. Seedlings grown with calcite have significant gains for several growth and physiological variables, and that the periphery of their root plugs are more colonized by the extramatrical phase of ectomycorrhizal fungi, thus improving root-plug cohesion. The authors discuss the operational scope of the results in relation to the tolerance of seedlings to environmental stress and the improvement of their quality, both in the nursery and in reforestation sites.
    Electronic ISSN: 2076-2607
    Topics: Biology
    Published by Molecular Diversity Preservation International
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  • 5
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    Hybrid Mesoporous Silica Nanoparticles Grafted with 2-(tert-butylamino)ethyl Methacrylate-b-poly(ethylene Glycol) Methyl Ether Methacrylate Diblock Brushes as Drug Nanocarrier (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-01-03
    Description: This paper introduces the synthesis of well-defined 2-(tert-butylamino)ethyl methacrylate-b-poly(ethylene glycol) methyl ether methacrylate diblock copolymer, which has been grafted onto mesoporous silica nanoparticles (PTBAEMA-b-PEGMEMA-MSNs) via atom transfer radical polymerization (ATRP). The ATRP initiators were first attached to the MSN surfaces, followed by the ATRP of 2-(tert-butylamino)ethyl methacrylate (PTBAEMA). CuBr2/bipy and ascorbic acid were employed as the catalyst and reducing agent, respectively, to grow a second polymer, poly(ethylene glycol) methyl ether methacrylate (PEGMEMA). The surface structures of these fabricated nanomaterials were then analyzed using Fourier Transform Infrared (FTIR) spectroscopy. The results of Thermogravimetric Analysis (TGA) show that ATRP could provide a high surface grafting density for polymers. Dynamic Light Scattering (DLS) was conducted to investigate the pH-responsive behavior of the diblock copolymer chains on the nanoparticle surface. In addition, multifunctional pH-sensitive PTBAEMA-b-PEGMEMA-MSNs were loaded with doxycycline (Doxy) to study their capacities and long-circulation time.
    Electronic ISSN: 1420-3049
    Topics: Chemistry and Pharmacology
    Published by Molecular Diversity Preservation International
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  • 6
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    Zinc Adequacy Is Essential for the Maintenance of Optimal Oral Health (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-03-30
    Description: Zinc, a metal found in the Earth’s crust, is indispensable for human health. In the human body, around 60% of zinc is present in muscles, 30% in bones, and the remaining 10% in skin, hair, pancreas, kidneys and plasma. An adequate zinc balance is essential for the maintenance of skeletal growth, development and function. It is also necessary for basic cellular functions including enzyme activation, cell signaling and energy metabolism. Inadequate zinc status is associated with a wide variety of systemic disorders including cardiovascular impairment, musculoskeletal dysfunctions and oromaxillary diseases. In this article, we briefly discuss the role of zinc deficiency in the genesis of various oromaxillary diseases, and explain why adequate zinc homeostasis is vital for the maintenance of oral and general health.
    Electronic ISSN: 2072-6643
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Published by Molecular Diversity Preservation International
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  • 7
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    Pollen Bee Aqueous Extract-Based Synthesis of Silver Nanoparticles and Evaluation of Their Anti-Cancer and Anti-Bacterial Activities (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-04-29
    Description: Bee pollens are rich source of essential amino acids and are often considered as complete food for human beings. Herein, we exploited the potential reducing abilities of Bee pollens extract for the eco-friendly preparation of silver nanoparticles (AgNPs-G). The resulting NPs were characterized using a combination of microscopic and spectroscopic techniques. The analyses confirm the formation of spherical Ag NPs. AgNPs-G obtained from the aqueous extract of bee pollens was used to study their antibacterial properties against Gram-positive and Gram-negative microbes using the Minimum Inhibitory Concentration 50 (MIC50) method. The antibacterial properties of AgNPs-G were compared to the properties of chemically synthesized Ag NPs (AgNPs-C) using sodium borohydride as a reducing agent. The green synthesized nanoparticles (AgNPs-G) exhibited a better antibacterial activity against most of the studied strains when compared to the chemically synthesized Ag NPs (AgNPs-C). In addition, the anti-cancer activity of Ag NPs was also studied against human liver and breast carcinoma cell lines by applying MTT-assay. The Ag NPs demonstrated considerable anticancer activity against the studied cell lines and exhibited high IC50 values in both MCF-7 and HepG2 cell lines.
    Electronic ISSN: 2227-9717
    Topics: Biology , Chemistry and Pharmacology
    Published by Molecular Diversity Preservation International
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  • 8
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    Development of a 3D Printed Coating Shell to Control the Drug Release of Encapsulated Immediate-Release Tablets (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-06-22
    Description: The use of 3D printing techniques to control drug release has flourished in the past decade, although there is no generic solution that can be applied to the full range of drugs or solid dosage forms. The present study provides a new concept, using the 3D printing technique to print a coating system in the form of shells with various designs to control/modify drug release in immediate-release tablets. A coating system of cellulose acetate in the form of an encapsulating shell was printed through extrusion-based 3D printing technology, where an immediate-release propranolol HCl tablet was placed inside to achieve a sustained drug release profile. The current work investigated the influence of shell composition by using different excipients and also by exploring the impact of shell size on the drug release from the encapsulated tablet. Three-dimensional printed shells with different ratios of rate-controlling polymer (cellulose acetate) and pore-forming agent (D-mannitol) showed the ability to control the amount and the rate of propranolol HCl release from the encapsulated tablet model. The shell-print approach also showed that space/gap available for drug dissolution between the shell wall and the enclosed tablet significantly influenced the release of propranolol HCl. The modified release profile of propranolol HCl achieved through enclosing the tablet in a 3D printed controlled-release shell followed Korsmeyer–Peppas kinetics with non-Fickian diffusion. This approach could be utilized to tailor the release profile of a Biopharmaceutics Classification System (BCS) class I drug tablet (characterized by high solubility and high permeability) to improve patient compliance and promote personalized medicine.
    Electronic ISSN: 2073-4360
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Published by Molecular Diversity Preservation International
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  • 9
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    Melatonin Regulatory Mechanisms and Phylogenetic Analyses of Melatonin Biosynthesis Related Genes Extracted from Peanut under Salinity Stress (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-07-06
    Description: Melatonin improves the tolerance of plants to various environmental stresses by protecting plant cells against oxidative stress damage. The objective of the current study was to determine whether exogenous melatonin (MT) treatments could help protecting peanut (Arachis hypogaea) seedlings against salinity stress. This was achieved by investigating enzymatic and non-enzymatic antioxidant systems and the expression of melatonin biosynthesis related genes in response to salinity stress with or without exogenous MT. The results showed a significant increase in the concentrations of reactive oxygen species (ROS) in peanut seedlings under salinity stress. The exogenous application of melatonin decreased the levels of ROS through the activation of antioxidant enzymes in peanut seedlings under salinity stress. Transcription levels of melatonin biosynthesis related genes such as N-acetylserotonin methyltransferase (ASMT1, ASMT2, ASMT3), tryptophan decarboxylase (TDC), and tryptamine 5-hydroxylase (T5H) were up-regulated with a 150 µM melatonin treatment under salinity stress. The results indicated that melatonin regulated the redox homeostasis by its ability to induce either enzymatic or non-enzymatic antioxidant systems. In addition, phylogenetic analysis of melatonin biosynthesis genes (ASMT1, ASMT2, ASMT3, TDC, T5H) were performed on a total of 56 sequences belonging to various plant species including five new sequences extracted from Arachis hypogaea (A. hypogaea). This was based on pairwise comparison among aligned nucleotides and predicted amino acids as well as on substitution rates, and phylogenetic inference. The analyzed sequences were heterogeneous and the A. hypogaea accessions were primarily closest to those of Manihot esculenta, but this needs further clarification.
    Electronic ISSN: 2223-7747
    Topics: Biology
    Published by Molecular Diversity Preservation International
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  • 10
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    Pharmacists as a Source of Advice on Medication Use for Athletes (2020)
    Molecular Diversity Preservation International
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    Publication Date: 2020-01-15
    Description: Background: The World Anti-Doping Agency (WADA) specifies substances that competitive sportspersons are not allowed to take. Some of these substances are contained in common medicines used in everyday medical practice and could be used by athletes by accident. Objectives: This study aimed to explore pharmacists’ knowledge and confidence in guiding athletes about the use of medicines in professional sport. Methods: Registered pharmacists in Australia were invited to participate in an online survey. The survey had five domains and aimed to identify pharmacists’ demographic information, interest in sport, familiarity with WADA guidelines, knowledge on prohibited drug classes, and their opinion about the role of pharmacists in educating athletes on medication use. Descriptive statistics were provided and where appropriate, Chi-square, Mann–Whitney and independent t-test were used to identify potential associations and difference between means. Results: One hundred and thirty-five pharmacists (response rate of 10.6%) completed the survey, with the majority indicating that they were not confident in advising athletes on medication use. Although most respondents believed that pharmacists have a role in the education of athletes to help avoid unintentional doping, only about a quarter indicated that they had sufficient knowledge to advise athletes. About one-half of the respondents could provide fully correct answers when asked to identify the WADA status of some commonly used drugs. Conclusions: The results of the survey indicate that upskilling is required to enable pharmacists in Australia to provide accurate medication advice to professional athletes.
    Electronic ISSN: 2226-4787
    Topics: Chemistry and Pharmacology
    Published by Molecular Diversity Preservation International
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