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https://www.readbyqxmd.com/read/28092854/biopharmaceutical-characterization-of-praziquantel-cocrystals-and-cyclodextrin-complexes-prepared-by-grinding
#1
Martina Cugovčan, Jasna Jablan, Jasmina Lovrić, Dominik Cinčić, Nives Galić, Mario Jug
Mechanochemical activation using several different co-grinding additives was applied as a green chemistry approach to improve physiochemical and biopharmaceutical properties of praziquantel (PZQ). Liquid assisted grinding with an equimolar amount of citric acid (CA), malic acid (MA), salicylic acid (SA) and tartaric acid (TA) gained in cocrystal formation, which all showed pH-dependent solubility and dissolution rate. However, the most soluble cocrystal of PZQ with MA was chemically unstable, as seen during the stability testing...
January 10, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28092833/study-of-molecular-interactions-between-chitosan-and-vi-antigen
#2
Natália de Farias Silva, Raimundo Lopes da Silva, Kalene de Oliveira Almeida, Antônio Edilson Sousa do Nascimento-Júnior, Davi do Socorro Barros Brasil, José Otávio Carréra Silva-Júnior, Francisco Martins Teixeira, Roseane Maria Ribeiro-Costa
Chitosan has attracted much interest due to its special physical and chemical properties related to drug administration. Nanoparticles delivery systems from Vi Antigen are a promising approach in the struggle against typhoid fever. In this paper, we reported the obtainment and the characterization of Vi Antigen by Infrared spectroscopy as well as Molecular Modeling and Computational Chemistry studies of the Chitosan-Vi Antigen interaction through theoretical models. The results of the theoretical and experimental Infrared spectroscopy showed important bands related to N-Acetyl and O-Acetyl groups present in Vi Antigen...
December 31, 2016: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28092831/dft-study-on-the-chemical-sensing-properties-of-b24n24-nanocage-toward-formaldehyde
#3
Zahra Rostami, Mansoureh Pashangpour, Reza Moradi
It has been previously shown that the toxic formaldehyde gas (H2CO) cannot be detected by pristine BC2N, carbon, and BN nanotubes, BC3 nanosheet and graphene. Herein, density functional theory calculations were employed to investigate the electronic and structural behavior of a pristine B24N24 nanocluster toward H2CO molecules. It was found that [4,6] BN bonds of the nanocluster are the most favorable sites for the H2CO adsorption, compared to the [4,8], and [6,8] ones. When an H2CO molecule is adsorbed on a [4,6] BN bond, an energy of about 16...
December 26, 2016: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28092826/synthesis-ph-dependent-photometric-and-electrochemical-investigation-redox-mechanism-and-biological-applications-of-novel-schiff-base-and-its-metallic-derivatives
#4
Abdur Rauf, Afzal Shah, Abdul Aziz Khan, Aamir Hassan Shah, Rashda Abbasi, Irfan Zia Qureshi, Saqib Ali
A novel Schiff base, 1-((2, 4-dimethylphenylimino)methyl)naphthalen-2-ol abbreviated as (HL) and its four metallic complexes were synthesized and confirmed by (1)H and (13)C NMR, FTIR, TGA and UV-Visible spectroscopy. Schiff base was also characterized by X-ray analysis. The photometric and electrochemical responses of all the synthesized compounds were investigated in a wide pH range. Structures of the compounds were optimized computationally for the evaluation of different physico-chemical parameters. On the basis of electrochemical results the redox mechanistic pathways of the compounds were proposed...
January 9, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28092824/chemically-modified-amino-porphyrin-tio2-for-the-degradation-of-acid-black-1-under-day-light-illumination
#5
Balu Krishnakumar, Avula Balakrishna, Cláudia T Arranja, Carlos M F Dias, Abilio J F N Sobral
In this paper, for the first time, chemically modified 5,10,15,20-meso-tetra-(para-amino)-phenyl-porphyrin/TiO2 (TPAPP/TiO2) was prepared and used for the degradation of an azo dye Acid Black 1 (AB 1) under direct sunlight. Initially, TiO2 was prepared by sol-gel method. Before making a TPAPP/TiO2 composite, the surface modification of TiO2 was carried out with glycidoxypropyltrimethoxy silane (GPTMS) which acts as a coupling agent. This is an epoxy terminated silane and could easily bond to the amino group of TPAPP through epoxy cleavage...
January 9, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28092802/signal-and-binding-i-physico-chemical-response-to-macromolecule-ligand-interactions
#6
REVIEW
Wlodzimierz Bujalowski, Maria J Jezewska, Paul J Bujalowski
Obtaining a detailed knowledge about energetics of ligand-macromolecule interactions is a prerequisite for elucidation of the nature, behavior, and activities of the formed complexes. The most commonly used methods in characterizing molecular interactions are physico-chemical techniques based mainly on spectroscopic, calorimetric, hydrodynamic, etc., measurements. The major advantage of the physico-chemical methods is that they do not require large quantities of material and, if performed carefully, do not perturb examined reactions...
January 3, 2017: Biophysical Chemistry
https://www.readbyqxmd.com/read/28092796/global-open-data-management-in-metabolomics
#7
REVIEW
Kenneth Haug, Reza M Salek, Christoph Steinbeck
Chemical Biology employs chemical synthesis, analytical chemistry and other tools to study biological systems. Recent advances in both molecular biology such as next generation sequencing (NGS) have led to unprecedented insights towards the evolution of organisms' biochemical repertoires. Because of the specific data sharing culture in Genomics, genomes from all kingdoms of life become readily available for further analysis by other researchers. While the genome expresses the potential of an organism to adapt to external influences, the Metabolome presents a molecular phenotype that allows us to asses the external influences under which an organism exists and develops in a dynamic way...
January 13, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28092766/effect-of-multi-walled-carbon-nanotubes-on-phytotoxicity-of-sediments-contaminated-by-phenanthrene-and-cadmium
#8
Biao Song, Guangming Zeng, Jilai Gong, Peng Zhang, Jiaqin Deng, Canhui Deng, Jin Yan, Piao Xu, Cui Lai, Chen Zhang, Min Cheng
To implement effective control and abatement programs for contaminants accumulating in sediments, strategies are needed for evaluating the quality of amended sediments. In this study, phytotoxicity of the sediments contaminated by cadmium and phenanthrene was evaluated after in situ remediation with multi-walled carbon nanotubes (MWCNTs) as adsorbents. Adsorption experiments and measurement of aqueous concentrations of the contaminants in overlying water were used to investigate the remediation effectiveness from physical and chemical aspects...
January 9, 2017: Chemosphere
https://www.readbyqxmd.com/read/28092763/growth-and-antioxidant-defense-responses-of-wheat-seedlings-to-di-n-butyl-phthalate-and-di-2-ethylhexyl-phthalate-stress
#9
Minling Gao, Youming Dong, Ze Zhang, Wenhua Song, Yun Qi
Phthalate acid esters (PAEs) are vital environmental hormone-like chemicals that are noxious to plants, animals, and human beings. In this study, the influences of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) on the seed germination, root morphology, and various physiological changes of wheat seedlings were investigated by analyzing superoxide anion (O2(-)) accumulation, antioxidant enzyme activity, and lipid peroxidation. DBP and DEHP were found to obviously inhibit germination only at high concentrations, but significantly affected root morphology even at lower concentrations...
January 5, 2017: Chemosphere
https://www.readbyqxmd.com/read/28092755/coagulation-flocculation-sequential-with-fenton-or-photo-fenton-processes-as-an-alternative-for-the-industrial-textile-wastewater-treatment
#10
Edison GilPavas, Izabela Dobrosz-Gómez, Miguel Ángel Gómez-García
In this study, the industrial textile wastewater was treated using a chemical-based technique (coagulation-flocculation, C-F) sequential with an advanced oxidation process (AOP: Fenton or Photo-Fenton). During the C-F, Al2(SO4)3 was used as coagulant and its optimal dose was determined using the jar test. The following operational conditions of C-F, maximizing the organic matter removal, were determined: 700 mg/L of Al2(SO4)3 at pH = 9.96. Thus, the C-F allowed to remove 98% of turbidity, 48% of Chemical Oxygen Demand (COD), and let to increase in the BOD5/COD ratio from 0...
January 13, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28092753/immobilization-and-reduction-of-bioavailability-of-lead-in-shooting-range-soil-through-hydrothermal-treatment
#11
Mohammad Nazrul Islam, Jeong-Hun Park
Immobilization of Pb in contaminated soil by hydrothermal treatment (HT) under subcritical conditions was investigated using a lab-scale apparatus. The Pb immobilization was evaluated thorough investigating the transformation of Pb fractions and by single chemical extraction. The results showed that HT and treatment temperature significantly affected the immobilization through redistribution of Pb fractions. The results of bioavailability and eco-toxicity assessment demonstrated a drastic decrease in the bioavailable fraction from 41...
January 13, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28092737/complex-molecular-changes-induced-by-chronic-progestogens-exposure-in-roach-rutilus-rutilus
#12
Gabor Maasz, Zita Zrinyi, Peter Takacs, Sandor Lovas, Istvan Fodor, Tibor Kiss, Zsolt Pirger
In our previous study, we measured 0.23-13.67ng/L progestogens (progesterone, drospirenone, levonorgestrel) in natural waters in the catchment area of the largest shallow lake of Central Europe, Lake Balaton. Progestogen contaminations act as potent steroids with mixed progestagenic, androgenic and mild estrogenic effects that is why our aim was to investigate the morphological and molecular effects of mixture of progesterone, drospirenone, and levonorgestrel in environmentally relevant (10ng/L) and higher (50 and 500ng/L) exposure concentrations in common roach, Rutilus rutilus...
January 13, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28092731/biological-removal-of-selenate-and-ammonium-by-activated-sludge-in-a-sequencing-batch-reactor
#13
J Mal, Y V Nancharaiah, E D van Hullebusch, P N L Lens
Wastewaters contaminated by both selenium and ammonium need to be treated prior to discharge into natural water bodies, but there are no studies on the simultaneous removal of selenium and ammonium. A sequencing batch reactor (SBR) was inoculated with activated sludge and operated for 90days. The highest ammonium removal efficiency achieved was 98%, while the total nitrogen removal was 75%. Nearly a complete chemical oxygen demand removal efficiency was attained after 16days of operation, whereas complete selenate removal was achieved only after 66days...
January 3, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28092688/buckled-two-dimensional-xene-sheets
#14
Alessandro Molle, Joshua Goldberger, Michel Houssa, Yong Xu, Shou-Cheng Zhang, Deji Akinwande
Silicene, germanene and stanene are part of a monoelemental class of two-dimensional (2D) crystals termed 2D-Xenes (X = Si, Ge, Sn and so on) which, together with their ligand-functionalized derivatives referred to as Xanes, are comprised of group IVA atoms arranged in a honeycomb lattice - similar to graphene but with varying degrees of buckling. Their electronic structure ranges from trivial insulators, to semiconductors with tunable gaps, to semi-metallic, depending on the substrate, chemical functionalization and strain...
January 16, 2017: Nature Materials
https://www.readbyqxmd.com/read/28092639/lithographic-patterning-of-antibodies-by-direct-lift-off-and-improved-surface-adhesion
#15
Sankalp Verma, Vivek Verma
The inherent property of antibodies binding to their antigen with high specificity makes them a strong candidate for sensing and detection applications. Microscale patterning of antibodies is desired for the miniaturization of sensors and fundamental cell biology studies. However, existing methodologies to pattern antibodies at the microscale are multi-step. In this work, we demonstrate microscale patterning of antibodies on a glass coverslip in a single step photolithography process. The microscale features of the photoresist were generated on the coverslip using photolithography, and the antibody solution was incubated...
January 16, 2017: Biofabrication
https://www.readbyqxmd.com/read/28092441/local-mode-analysis-decoding-ir-spectra-by-visualizing-molecular-details
#16
Matthias Massarczyk, Till Rudack, Jürgen Schlitter, Jens Kuhne, Carsten Kötting, Klaus Gerwert
Integration of experimental and computational approaches to investigate chemical reactions in proteins has proven to be very successful. Experimentally, time-resolved FTIR difference-spectroscopy monitors chemical reactions at atomic detail. To decode detailed structural information encoded in IR spectra, QM/MM calculations are performed. Here, we present a novel method which we call Local Mode Analysis (LMA) for calculating IR spectra and assigning spectral IR bands on the basis of movements of nuclei and partial charges from just a single QM/MM trajectory...
January 16, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28092427/layer-dependence-and-light-tuning-surface-potential-of-2d-mos2-on-various-substrates
#17
Feng Li, Junjie Qi, Minxuan Xu, Jiankun Xiao, Yuliang Xu, Xiankun Zhang, Shuo Liu, Yue Zhang
Here surface potential of chemical vapor deposition (CVD) grown 2D MoS2 with various layers is reported, and the effect of adherent substrate and light illumination on surface potential of monolayer MoS2 are investigated. The surface potential of MoS2 on Si/SiO2 substrate decreases from 4.93 to 4.84 eV with the increase in the number of layer from 1 to 4 or more. Especially, the surface potentials of monolayer MoS2 are strongly dependent on its adherent substrate, which are determined to be 4.55, 4.88, 4.93, 5...
January 16, 2017: Small
https://www.readbyqxmd.com/read/28092425/chemical-composition-of-the-essential-oil-of-nigeria-grown-hoslundia-opposita-vahl-lamiaceae-dried-leaves-and-its-bioactivity-against-cowpea-seed-bruchid
#18
Samuel Adelani Babarinde, Olufemi Olutoyin Richard Pitan, Ganiyu Olatunji Olatunde, Michael Oluwole Ajala
Due to several ecological and human hazards of synthetic pesticides in postharvest crop protection, there is the need to search for eco-friendly alternatives. In this study, chemical composition and insecticidal activities of essential oil (EO) obtained from Hoslundia opposita dried leaves were evaluated against cowpea seed bruchid. Eight constituents, predominated by oxygenated monoterpenes (78.86%), were identified using GC-MS. The constituents were 1,8-cineole (1; 61.15%), followed by α-terpineol (2; 16...
January 16, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28092424/continuous-films-of-self-assembled-graphene-quantum-dots-for-n-type-doping-of-graphene-by-uv-triggered-charge-transfer
#19
Myung Jin Park, Yuna Kim, Youngsoo Kim, Byung Hee Hong
The demands to examine components serving as one of the active layers in heterostructures of 2D materials have been recently increasing. Nanomaterials synthesized from a solution process and their self-assembly can provide a promising route to build a new type of mixed dimensional heterostructures, and several methodologies have been reported previously to construct 2D assemblies from colloidal nanostructures in solution. Graphene quantum dots (GQDs), receiving much interest due to the tunable optical band gap and the capability of chemical functionalization, are considered as emerging nanomaterials for various optoelectronic and biological applications...
January 16, 2017: Small
https://www.readbyqxmd.com/read/28092409/quantification-of-brown-and-white-adipose-tissue-based-on-gaussian-mixture-model-using-water-fat-and-t2-mri-in-adolescents
#20
Steve C N Hui, Jacky K L Ko, Teng Zhang, Lin Shi, David K W Yeung, Defeng Wang, Queenie Chan, Winnie C W Chu
PURPOSE: To develop a technique for the separation and quantification of brown adipose tissue (BAT) and white adipose tissue (WAT) using fat fraction and T2* intensity based on the Gaussian mixture model (GMM). MATERIALS AND METHODS: Chemical-shift water-fat and T2* images were acquired at the neck, supraclavicular, interscapular, and paravertebral regions in 24 volunteers (Obese: n = 12, female/male = 6/6, body mass index [BMI] = 31.3 ± 2.3 kg/m(2) , age = 16...
January 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
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