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https://www.readbyqxmd.com/read/28214750/propagation-of-thickness-shear-waves-in-a-periodically-corrugated-quartz-crystal-plate-and-its-application-exploration-in-acoustic-wave-filters
#1
Peng Li, Li Cheng
The propagation of thickness shear waves in a periodically corrugated quartz crystal plate is investigated in the present paper using a power series expansion technique. In the proposed simulation model, an equivalent continuity of shear stress moment is introduced as an approximation to handle sectional interfaces with abrupt thickness changes. The Bloch theory is applied to simulate the band structures for three different thickness variation patterns. It is shown that the power series expansion method exhibits good convergence and accuracy, in agreement with results by finite element method (FEM)...
February 7, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28214672/evaluation-of-molecular-chaperone-drug-function-regorafenib-and-%C3%AE-cyclodextrins
#2
Xiurong Hu, Mengying Sun, Yang Li, Guping Tang
Regorafenib (RG) was an oral multi-kinase inhibitor with poor water solubility. In order to enhance the drug's solubility, dissolution and bioavailability, the binary molecular chaperone drug between RG and β-cyclodetrin (β-CD) had prepared by co-crystallization. The structure of RG-β-CD was characterized by thermal analysis, powder X-ray diffraction, infrared spectroscopy and nuclear magnetic resonance. Phase-solubility study revealed the higher solubility and complexing ability of β-CDwith RG.The solubility and dissolution of RG-β-CD was significantly enhanced in pH 1...
February 7, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28214627/up-conversion-luminescence-in-yb-3-er-3-tm-3-co-doped-al2o3-tio2-nano-composites
#3
Teboho Patrick Mokoena, Ella Cebisa Linganiso, Vinod Kumar, Hendrik C Swart, So-Hye Cho, Odireleng Martin Ntwaeaborwa
The sol gel method was used to prepare rare-earths (Yb(3+)-Er(3+) and Yb(3+)-Tm(3+)) co-doped Al2O3-TiO2 nano-composite powder phosphors and their up-conversion luminescence properties were investigated. Mixed oxides of titania (TiO2) rutile phase and an early stage crystallization of alumina (Al2O3) phase were confirmed from the X-ray diffraction data with the average crystallite size of ∼36nm. The rutile phase TiO2 was further confirmed by selected area diffraction analysis of the composites. Microscopy analysis showed interesting rod-like morphologies with rough surfaces indicating that a spherulitic growth process took place during the crystal growth...
February 13, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28214546/effect-of-cyclophosphamide-on-the-solid-form-of-mannitol-during-lyophilization
#4
Krupaliben Patel, Bhushan Munjal, Arvind K Bansal
Mannitol is a commonly used bulking agent in lyophilized formulations. It can crystallize into multiple solid forms during lyophilization thereby exhibiting phase heterogeneity and variability in product performance. In this manuscript, we studied the effect of cyclophosphamide (CPA), an anticancer drug, on the solid form of mannitol during lyophilization from aqueous solutions. Freeze-concentration studies were performed in the DSC while lyophilization was performed in a lab scale freeze dryer. DSC experiments revealed two-stage crystallization of mannitol (1...
February 15, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28214190/biofilm-formation-by-staphylococcus-aureus-isolates-from-a-dental-clinic-in-konya-turkey
#5
Emrah Torlak, Emre Korkut, Ali T Uncu, Yağmur Şener
The ability of Staphylococcus aureus to form biofilm is considered to be a major virulence factor influencing its survival and persistence in both the environment and the host. Biofilm formation in S. aureus is most frequently associated with production of polysaccharide intercellular adhesion by ica operon-encoded enzymes. The present work aimed at evaluating the in vitro biofilm production and presence of the icaA and icaD genes in S. aureus isolates from a dental clinic in Konya, Turkey. The surfaces of inanimate objects were sampled over a period of six months...
February 14, 2017: Journal of Infection and Public Health
https://www.readbyqxmd.com/read/28213526/structural-and-mechanistic-insights-into-hemoglobin-catalyzed-hydrogen-sulfide-oxidation-and-the-fate-of-polysulfide-products
#6
Victor Vitvitsky, Pramod K Yadav, Sojin An, Javier Seravalli, Uhn-Soo Cho, Ruma Banerjee
Hydrogen sulfide is a cardioprotective signaling molecule but is toxic at elevated concentrations. Red blood cells can synthesize H2S but lacking organelles, cannot dispose off H2S via the mitochondrial sulfide oxidation pathway. We have recently shown that at high sulfide concentrations, ferric hemoglobin oxidizes H2S to a mixture of thiosulfate and iron-bound polysulfides in which the latter species predominates. Here, we report the crystal structure of human hemoglobin containing low-spin ferric sulfide, the first intermediate in heme-catalyzed sulfide oxidation...
February 17, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28213222/development-of-a-qcm-d-biosensor-for-ochratoxin-a-detection-in-red-wine
#7
Aleksandra Karczmarczyk, Karsten Haupt, Karl-Heinz Feller
Ochratoxin A (OTA), a highly toxic compound, is one of the most widely spread mycotoxins that contaminates a large variety of agricultural commodities. Due to its presence in the food chain, it imposes a hazard on both human and animal health. Therefore, there is a need for precise, fast and simple methods for toxin quantification. Herein, a novel sensor based on a quartz crystal microbalance with dissipation monitoring (QCM-D) and antibodies for specific analyte recognition was developed for rapid and sensitive detection of OTA in red wine...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28213143/selective-detection-of-cu-2-and-co-2-in-aqueous-media-asymmetric-chemosensors-crystal-structure-and-spectroscopic-studies
#8
Samira Gholizadeh Dogaheh, Hamid Khanmohammadi, E Carolina Sañudo
Two new azo-azomethine receptors, H2L(1) and H2L(2), containing hydrazine, naphthalene and different electron withdrawing groups, Cl and NO2, have been designed and synthesized for qualitative and quantitative detection of Cu(2+) and Co(2+) in aqueous media. The crystal structure of H2L(1)is reported. The H2L(1)was used as a chemosensor for selective detection of trace amount of Cu(2+) in aqueous media. H2L(2) was also applied to naked-eye distinction of Cu(2+) and Co(2+) from other transition metal ions in aqueous media...
February 8, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28213139/antimycobacterial-antimicrobial-activity-experimental-ft-ir-ft-raman-nmr-uv-vis-dsc-and-dft-transition-state-chemical-reactivity-nbo-nlo
#9
Poonam Rawat, R N Singh, Alok Ranjan, Sartaj Ahmad, Rajat Saxena
As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well...
February 11, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28212931/uv-protective-poly-lactic-acid-rosin-films-for-sustainable-packaging
#10
Meenu Narayanan, Sravanthi Loganathan, Ravi Babu Valapa, Sabu Thomas, T O Varghese
Recently, biopolymer based plastic materials are regarded as potential alternative for conventional plastics of fossil fuel origin in order to compensate depleting petroleum resources and address environmental pollution issues. Poly(lactic acid) (PLA) is one among the biopolymers which is rapidly commercialized for food packaging application. However, the demerits accompanied with PLA like brittle nature, slower crystallization rate, poor gas barrier and high ultraviolet radiation transmission properties confines its commercial application in food packaging sector...
February 14, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28212595/preparation-and-characterization-of-gold-nanoparticles-in-the-presence-of-citrate-and-soybean-seed-extract-in-an-acidic-conditions
#11
Ebrahim Izadi, Ali Rasooli, Abolfazl Akbarzadeh, Soodabeh Davaran
Through the present study, an eco-friendly method was used to synthesize the gold nanoparticles (GNPs) by using the sodium citrate and extract of the soybean seed as reducing the agents at PH 3. X-Ray diffraction (XRD) method was used to evaluate the crystal structure of as-synthesized NPs and it's revealed that this method leads to well crystallized GNPs. In order to determine the particle size and their distribution, field emission scanning microscopy (FE-SEM) and dynamic light scattering (DLS) were used...
February 17, 2017: Drug Research
https://www.readbyqxmd.com/read/28212590/the-july-effect-on-maternal-peripartum-complications-before-and-after-resident-duty-hour-reform-a-population-based-retrospective-cohort-study
#12
Ithan D Peltan, Crystal E Brown, Alson K Burke, Eric J Chow, Ali Rowhani-Rahbar, Matthew R Crull
Objective To compare maternal birth complications early versus late in the academic year and to evaluate the impact of resident work hour limitation on the "July effect." Study Design We conducted a retrospective, population-based cohort study of 628,414 singleton births in Washington State from 1987 to 2012 measuring the adjusted risk of maternal peripartum complications early (July/August) versus late (April/May) in the academic year. To control for seasonal outcome variation unrelated to trainees' involvement in care as well as long-term trends in maternal complications unrelated to variation in trainees' effect on outcomes across the academic year, we employed difference-in-differences methods contrasting outcomes at teaching to nonteaching hospitals for deliveries before and after restriction of resident work hours in July 2003...
February 17, 2017: American Journal of Perinatology
https://www.readbyqxmd.com/read/28212584/hyaluronic-acid-serum-albumin-conjugate-based-nanoparticles-for-targeted-cancer-therapy
#13
Ravit Edelman, Yehuda G Assaraf, Inna Levitzky, Tal Shahar, Yoav D Livney
Multiple carcinomas including breast, ovarian, colon, lung and stomach cancer, overexpress the hyaluronic acid (HA) receptor, CD44. Overexpression of CD44 contributes to key cancer processes including tumor invasion, metastasis, recurrence, and chemoresistance. Herein, we devised novel targeted nanoparticles (NPs) for delivery of anticancer chemotherapeutics, comprised of self-assembling Maillard reaction-based conjugates of HA and bovine serum albumin (BSA). HA served as the hydrophilic block, and as the ligand for actively targeting cancer cells overexpressing CD44...
February 15, 2017: Oncotarget
https://www.readbyqxmd.com/read/28212500/cyto-genotoxic-and-dna-methylation-changes-induced-by-different-crystal-phases-of-tio2-np-in-bronchial-epithelial-16-hbe-cells
#14
Manosij Ghosh, Deniz Öner, Radu-Corneliu Duca, Stevan M Cokic, Sven Seys, Stef Kerkhofs, Kirsten Van Landuyt, Peter Hoet, Lode Godderis
With the increase in use of TiO2-np, a better understanding of their safety is important. In the present study the effect of different crystal phases of TiO2-np (anatase, rutile and anatase: rutile mixture; 20-26nm) were studied for cyto-genotoxicity and global DNA methylation and hydroxymethylation. Cytotoxic response was observed at a concentration of 25μg/ml for the particles tested. Results of comet and micronucleus (with and without CytB) assays revealed significant genotoxic effect of these particles...
February 10, 2017: Mutation Research
https://www.readbyqxmd.com/read/28212388/multiple-processes-in-two-dimensional-visual-statistical-learning
#15
Eiichi Hoshino, Ken Mogi
Knowledge about the arrangement of visual elements is an important aspect of perception. This study investigates whether humans learn rules of two-dimensional abstract patterns (exemplars) generated from Reber's artificial grammar. The key question is whether the subjects can implicitly learn them without explicit instructions, and, if so, how they use the acquired knowledge to judge new patterns (probes) in relation to their finite experience of the exemplars. The analysis was conducted using dissimilarities among patterns, which are defined with n-gram probabilities and the Levenshtein distance...
2017: PloS One
https://www.readbyqxmd.com/read/28212347/molecularly-imprinted-sol-gel-based-qcm-sensor-arrays-for-the-detection-and-recognition-of-volatile-aldehydes
#16
Chuanjun Liu, Bartosz Wyszynski, Rui Yatabe, Kenshi Hayashi, Kiyoshi Toko
The detection and recognition of metabolically derived aldehydes, which have been identified as important products of oxidative stress and biomarkers of cancers; are considered as an effective approach for early cancer detection as well as health status monitoring. Quartz crystal microbalance (QCM) sensor arrays based on molecularly imprinted sol-gel (MISG) materials were developed in this work for highly sensitive detection and highly selective recognition of typical aldehyde vapors including hexanal (HAL); nonanal (NAL) and bezaldehyde (BAL)...
February 16, 2017: Sensors
https://www.readbyqxmd.com/read/28212300/amorphous-amorphous-phase-separation-in-api-polymer-formulations
#17
Christian Luebbert, Fabian Huxoll, Gabriele Sadowski
The long-term stability of pharmaceutical formulations of poorly-soluble drugs in polymers determines their bioavailability and therapeutic applicability. However, these formulations do not only often tend to crystallize during storage, but also tend to undergo unwanted amorphous-amorphous phase separations (APS). Whereas the crystallization behavior of APIs in polymers has been measured and modeled during the last years, the APS phenomenon is still poorly understood. In this study, the crystallization behavior, APS, and glass-transition temperatures formulations of ibuprofen and felodipine in polymeric PLGA excipients exhibiting different ratios of lactic acid and glycolic acid monomers in the PLGA chain were investigated by means of hot-stage microscopy and DSC...
February 15, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28212032/chrodrimanins-k-n-and-related-meroterpenoids-from-the-fungus-penicillium-sp-scs-kfd09-isolated-from-a-marine-worm-sipunculus-nudus
#18
Fan-Dong Kong, Qing-Yun Ma, Sheng-Zhuo Huang, Pei Wang, Jun-Feng Wang, Li-Man Zhou, Jing-Zhe Yuan, Hao-Fu Dai, You-Xing Zhao
Six new meroterpenoids, chrodrimanins K-N (1-4), including two uncommon chlorinated ones (1 and 2), and verruculides B2 (5) and B3 (6), as well as seven known ones (7-13), were isolated from the fermentation broth of Penicillium sp. SCS-KFD09 isolated from a marine worm, Sipunculus nudus, from Haikou Bay, China. The structures including the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data, X-ray diffraction analysis, and ECD spectra analysis along with quantum ECD calculations...
February 17, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28212030/revisiting-silicalite-1-nucleation-in-clear-solution-by-electrochemical-impedance-spectroscopy
#19
Gert Brabants, Maxim Hubin, Erwin Konrad Reichel, Bernhard Jakoby, Eric Breynaert, Francis Taulelle, Johan A Martens, Christine E A Kirschhock
EIS was used to detect and investigate nucleation in silicalite-1 clear solutions. Whereas zeolite nucleation was previously assumed to be a step event, inducing a sharp discontinuity around a Si/OH ratio of 1, complex bulk conductivity measurements at elevated temperatures reveal a gradual decay of the conductivity with increased silicon concentrations. Inverse Laplace transformation of the complex conductivity allows to observe the chemical exchange phenomena governing nano-aggregate formation. At low temperatures, the fast exchange between dissociated ions and ion pairs leads to a gradual decay of the conductivity with increasing silicon content...
February 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28212012/-meyeniins-a-c-novel-hexahydroimidazo-1-5-c-thiazole-derivatives-from-the-tubers-of-lepidium-meyenii-complete-structural-elucidation-by-biomimetic-synthesis-and-racemic-crystallization
#20
Min Zhou, Hang-Ying Ma, Zhi-Hua Liu, Guang-Yu Yang, Gang Du, Yan-Qing Ye, Gan-Peng Li, Qiu-Fen Hu
(+)-Meyeniins A-C (1-3), a novel class of sulfur-containing hexahydroimidazo[1,5-c]thiazole derivatives, were isolated from the tubers of Lepidium meyenii cultivated in Lijiang, Yunnan Province, China. Guided by their biosynthetic hypothesis, a stereocontrolled biomimetic synthesis of meyeniins A-C and their individual enantiomers was efficiently accomplished by a combination of a condensation reaction and Edman degradation. The formation of high-quality crystals for X-ray crystallography occurred much more readily from a racemic mixture of (±)-meyeniin A than with the single enantiomer alone in this case...
February 17, 2017: Journal of Agricultural and Food Chemistry
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