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https://www.readbyqxmd.com/read/28088634/chitosan-g-poly-n-isopropylacrylamide-copolymers-as-delivery-carriers-for-intracameral-pilocarpine-administration
#1
Jui-Yang Lai, Li-Jyuan Luo
This study reports, for the first time, the development of a chitosan-g-poly(N-isopropylacrylamide) (Chi-PN) biodegradable in situ gelling delivery system for ocular pilocarpine administration through intracameral injection. The number of thermo-responsive polymer segments grafted onto the chitosan via carbodiimide-mediated formation of amide linkages was greatly affected by varying the feeding amount of carboxyl-terminated poly(N-isopropylacrylamide) in the synthesis, thereby determining the phase transition temperature and enzymatic degradability of Chi-PN materials...
January 11, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28088456/development-of-a-predictive-model-for-the-long-term-stability-assessment-of-drug-in-adhesive-transdermal-films-using-polar-pressure-sensitive-adhesives-as-carrier-matrix
#2
Clémence Chenevas-Paule, Hans-Michael Wolff, Mark Ashton, Martin Schubert, Kalliopi Dodou
Drug crystallization in transdermal drug delivery systems (TDDS) is a critical quality defect. The impact of drug load and hydration on the physical stability of polar (acrylic) drug-in-adhesive (DIA) films was investigated with the objective to identify predictive formulation parameters with respect to drug solubility and long-term stability. Medicated acrylic films were prepared over a range of drug concentrations below and above saturation solubility; and were characterized by FTIR, differential scanning calorimetry (DSC), polarized microscopy and Dynamic Vapor Sorption (DVS) analysis...
January 11, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28088154/vibrational-properties-of-anhydrous-and-partially-hydrated-uranyl-fluoride
#3
M C Kirkegaard, J Langford, J Steill, B Anderson, A Miskowiec
Uranyl fluoride (UO2F2) is a hygroscopic powder with two main structural phases: an anhydrous crystal and a partially hydrated crystal of the same R3¯m symmetry. The formally closed-shell electron structure of anhydrous UO2F2 is amenable to density functional theory calculations. We use density functional perturbation theory (DFPT) to calculate the vibrational frequencies of the anhydrous crystal structure and employ complementary inelastic neutron scattering and temperature-dependent Raman scattering to validate those frequencies...
January 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28088151/phase-transition-of-a-symmetric-diblock-copolymer-induced-by-nanorods-with-different-surface-chemistry
#4
Yu-Qi Guo, Jun-Xing Pan, Min-Na Sun, Jin-Jun Zhang
We investigate the phase transition of a symmetric diblock copolymer induced by nanorods with different surface chemistry. The results demonstrate that the system occurs the phase transition from a disordered structure to ordered parallel lamellae and then to the tilted layered structure as the number of rods increases. The dynamic evolution of the domain size and the order parameter of the microstructure are also examined. Furthermore, the influence of rod property, rod-phase interaction, rod-rod interaction, rod length, and polymerization degree on the behavior of the polymer system is also investigated systematically...
January 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28088133/droplet-growth-during-vapor-liquid-transition-in-a-2d-lennard-jones-fluid
#5
Jiarul Midya, Subir K Das
Results for the kinetics of vapor-liquid phase transition have been presented from the molecular dynamics simulations of a single component two-dimensional Lennard-Jones fluid. The phase diagram for the model, primary prerequisite for this purpose, has been obtained via the Monte Carlo simulations. Our focus is on the region very close to the vapor branch of the coexistence curve. Quenches to such region provide morphology that consists of disconnected circular clusters in the vapor background. We identified that these clusters exhibit diffusive motion and grow via sticky collisions among them...
January 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28088082/nature-of-phase-transitions-in-ammonium-oxofluorovanadates-a-vibrational-spectroscopy-study-of-nh4-3vo2f4-and-nh4-3vof5
#6
REVIEW
Yu V Gerasimova, A S Oreshonkov, N M Laptash, A N Vtyurin, A S Krylov, N P Shestakov, A A Ershov, A G Kocharova
Two ammonium oxofluorovanadates, (NH4)3VO2F4 and (NH4)3VOF5, have been investigated by temperature-dependent infrared and Raman spectroscopy methods to determine the nature of phase transitions (PT) in these compounds. Dynamics of quasioctahedral groups was simulated within the framework of semi-empirical approach, which justified the cis-conformation of VO2F4(3-) (C2v) and the C4v geometry of VOF5(3-). The observed infrared and Raman spectra of both compounds at room temperature (RT) revealed the presence at least of two crystallographically independent octahedral groups...
January 4, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28087763/circadian-kinetics-of-cell-cycle-progression-in-adult-neurogenic-niches-of-a-diurnal-vertebrate
#7
Veronica Akle, Alexander J Stankiewicz, Vasili Kharchenko, Lili Yu, Peter V Kharchenko, Irina V Zhdanova
: The circadian system may regulate adult neurogenesis via intracellular molecular clock mechanisms or by modifying the environment of neurogenic niches, with daily variation in growth factors or nutrients depending on the animal's diurnal or nocturnal life-style. In a diurnal vertebrate, zebrafish, we studied circadian distribution of immunohistochemical markers of the cell division cycle (CDC) in five of the sixteen neurogenic niches of adult brain, the dorsal telencephalon, habenula, preoptic area, hypothalamus and cerebellum...
January 13, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28087712/pdx1-dynamically-regulates-pancreatic-ductal-adenocarcinoma-initiation-and-maintenance
#8
Nilotpal Roy, Kenneth K Takeuchi, Jeanine M Ruggeri, Peter Bailey, David Chang, Joey Li, Laura Leonhardt, Sapna Puri, Megan T Hoffman, Shan Gao, Christopher J Halbrook, Yan Song, Mats Ljungman, Shivani Malik, Christopher V E Wright, David W Dawson, Andrew V Biankin, Matthias Hebrok, Howard C Crawford
Aberrant activation of embryonic signaling pathways is frequent in pancreatic ductal adenocarcinoma (PDA), making developmental regulators therapeutically attractive. Here we demonstrate diverse functions for pancreatic and duodenal homeobox 1 (PDX1), a transcription factor indispensable for pancreas development, in the progression from normal exocrine cells to metastatic PDA. We identify a critical role for PDX1 in maintaining acinar cell identity, thus resisting the formation of pancreatic intraepithelial neoplasia (PanIN)-derived PDA...
December 15, 2016: Genes & Development
https://www.readbyqxmd.com/read/28087598/bayesian-network-inference-modeling-identifies-trib1-as-a-novel-regulator-of-cell-cycle-progression-and-survival-in-cancer-cells
#9
Rina Gendelman, Heming Xing, Olga K Mirzoeva, Preeti Sarde, Christina Curtis, Heidi Feiler, Paul McDonagh, Joe W Gray, Iya Khalil, W Michael Korn
Molecular networks governing cellular responses to targeted therapies are complex dynamic systems with non-intuitive behaviors. Here we applied a novel computational strategy to infer probabilistic causal relationships between network components based on gene expression. We constructed a model comprised of an ensemble of networks using multidimensional data from cell line models of cell cycle arrest caused by inhibition of MEK1/2. Through simulation of reverse-engineered Bayesian network modeling, we generated predictions of G1-S transition...
January 13, 2017: Cancer Research
https://www.readbyqxmd.com/read/28086921/a-randomized-controlled-trial-focusing-on-socio-economic-status-for-promoting-vegetable-intake-among-adults-using-a-web-based-nutrition-intervention-programme-study-protocol
#10
Saki Nakamura, Takayo Inayama, Takashi Arao
BACKGROUND: Web-based nutritional education programmes appear to be comparable to those delivered face-to-face. However, no existing web-based nutrition education or similar programme has yet been evaluated with consideration of socio-economic status. The objective of a nutritional education programme of promoting vegetable intake designed a randomized controlled trial (RCT) is to evaluate the results of intervention and to determine how socio-economic status influences the programme effects...
January 13, 2017: BMC Public Health
https://www.readbyqxmd.com/read/28081487/comparative-genome-wide-phylogenetic-and-expression-analysis-of-sbp-genes-from-potato-solanum-tuberosum
#11
Musa Kavas, Aslıhan Kurt Kızıldoğan, Büşra Abanoz
Flowering time is a very important phase in transition to reproductive stage of life in higher plants. SQUAMOSA promoter-binding protein (SBP) gene family encodes plant-specific transcription factors that are involved in regulation of several developmental processes, especially flowering. Although SBP-box genes have been identified in different plants, there have been no study indicating the regulatory effect of SBP box in potato flowering. Here, we report for the first time the identification and characterization of SBP-box transcription factors as well as determination of expression level of SBP-box genes in Solanum tuberosum L...
January 4, 2017: Computational Biology and Chemistry
https://www.readbyqxmd.com/read/28080071/nanoscale-engineering-in-vo2-nanowires-via-direct-electron-writing-process
#12
Zhenhua Zhang, Hua Guo, Wenqiang Ding, Bin Zhang, Yue Lu, Xiaoxing Ke, Weiwei Liu, Fu-Rong Chen, Manling Sui
Controlling phase transition in functional materials at nano-scale is not only of broad scientific interest, but also important for practical applications in the fields of renewable energy, information storage, transducer, sensor, etc. As a model functional material, vanadium dioxide (VO2) has its metal-insulator transition (MIT) usually at a sharp temperature around 68 °C. Here we report a focused electron beam can directly lower down the transition temperature of a nano-area to room temperature without pre-patterning the VO2...
January 12, 2017: Nano Letters
https://www.readbyqxmd.com/read/28080065/level-spectrum-and-charge-relaxation-in-a-silicon-double-quantum-dot-probed-by-dual-gate-reflectometry
#13
Alessandro Crippa, Romain Maurand, Dharmraj Kotekar-Patil, Andrea Corna, Heorhii Bohuslavskyi, Alexei O Orlov, Patrick Fay, Romain Laviéville, Sylvain Barraud, Maud Vinet, Marc Sanquer, Silvano De Franceschi, Xavier Jehl
We report on dual-gate reflectometry in a metal-oxide-semiconductor double-gate silicon transistor operating at low temperature as a double quantum dot device. The reflectometry setup consists of two radio frequency resonators respectively connected to the two gate electrodes. By simultaneously measuring their dispersive responses, we obtain the complete charge stability diagram of the device. Electron transitions between the two quantum dots and between each quantum dot and either the source or the drain contact are detected through phase shifts in the reflected radio frequency signals...
January 12, 2017: Nano Letters
https://www.readbyqxmd.com/read/28080056/metadynamics-simulations-distinguish-short-and-long-residence-time-inhibitors-of-cyclin-dependent-kinase-8
#14
Donatella Callegari, Alessio Lodola, Daniele Pala, Silvia Rivara, Marco Mor, Andrea Rizzi, Anna Maria Capelli
The duration of drug efficacy in vivo is a key aspect primarily addressed during the lead optimization phase of drug discovery. Hence, the availability of robust computational approaches that can predict the residence time of a compound at its target would accelerate candidate selection. Nowadays the theoretical prediction of this parameter is still very challenging. Starting from methods reported in the literature, we set up and validated a new metadynamics (META-D)-based protocol that was used to rank the experimental residence times of 10 arylpyrazole cyclin-dependent kinase 8 (CDK8) inhibitors for which target-bound X-ray structures are available...
January 12, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28080051/prediction-of-bond-dissociation-energies-heat-of-formation-for-diatomic-transition-metal-compounds-ccsd-t-works
#15
Zongtang Fang, Monica Vasiliu, Kirk A Peterson, David A Dixon
It was recently reported (J. Chem. Theory Comput. 2015, 11, 2036-2052) that the coupled cluster singles and doubles with perturbative triples method, CCSD(T), should not be used as a benchmark tool for the prediction of dissociation energies (heats of formation) for the 1st row transition metal diatomics based on a comparison with the experimental thermodynamic values for a set of 20 diatomics. In the present work the bond dissociation energies as well as the heats of formation for those diatomics have been calculated by the Feller-Peterson-Dixon approach at the CCSD(T)/complete basis set (CBS) level of theory including scalar relativistic corrections and correlation of the outer shell of core electrons in addition to the valence electrons...
January 12, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28080049/modeling-diversity-in-structures-of-bacterial-outer-membrane-lipids
#16
Huilin Ma, Daniel D Cummins, Natalie Brooke Edelstein, Jerry Gomez, Aliza Khan, Masud Dikita Llewellyn, Tara Picudella, Sarah Rose Willsey, Shikha Nangia
Lipopolysaccharides are vital components of the outer membrane of gram-negative bacteria, and they act as extremely strong stimulators of innate immunity in diverse eukaryotic species. The primary immunostimulatory center of the LPS molecule is lipid A-a disaccharide-bound lipophilic domain. Considering the broad diversity in bacterial species, there are variations in the lipid A structure and their immunogenic potency. In this work, we model the lipid A structures of eight commensal or human pathogenic bacterial species: Helicobacter pylori, Porphyromonas gingivalis, Bacteroides fragilis, Bordetella pertussis, Chlamydia trachomatis, Campylobacter jejuni, Neisseria meningitidis, and Salmonella minnesota...
January 12, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28079975/edge-states-and-topological-phase-transitions-in-chains-of-dielectric-nanoparticles
#17
Sergey Kruk, Alexey Slobozhanyuk, Denitza Denkova, Alexander Poddubny, Ivan Kravchenko, Andrey Miroshnichenko, Dragomir Neshev, Yuri Kivshar
Recently introduced field of topological photonics aims to explore the concepts of topological insulators for novel phenomena in optics. Here polymeric chains of subwavelength silicon nanodisks are studied and it is demonstrated that these chains can support two types of topological edge modes based on magnetic and electric Mie resonances, and their topological properties are fully dictated by the spatial arrangement of the nanoparticles in the chain. It is observed experimentally and described how theoretically topological phase transitions at the nanoscale define a change from trivial to nontrivial topological states when the edge mode is excited...
January 12, 2017: Small
https://www.readbyqxmd.com/read/28079961/highly-porous-thermoelectric-nanocomposites-with-low-thermal-conductivity-and-high-figure-of-merit-from-large-scale-solution-synthesized-bi2-te2-5-se0-5-hollow-nanostructures
#18
Biao Xu, Tianli Feng, Matthias T Agne, Lin Zhou, Xiulin Ruan, G Jeffery Snyder, Yue Wu
To enhance the performance of thermoelectric materials and enable access to their widespread applications, it is beneficial yet challenging to synthesize hollow nanostructures in large quantities, with high porosity, low thermal conductivity (κ) and excellent figure of merit (z T). Herein we report a scalable (ca. 11.0 g per batch) and low-temperature colloidal processing route for Bi2 Te2.5 Se0.5 hollow nanostructures. They are sintered into porous, bulk nanocomposites (phi 10 mm×h 10 mm) with low κ (0...
January 12, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28079159/socs1-favors-the-epithelial-mesenchymal-transition-in-melanoma-promotes-tumor-progression-and-prevents-antitumor-immunity-by-pd-l1-expression
#19
R Berzaghi, V S C Maia, F V Pereira, F M Melo, M S Guedes, C S T Origassa, J B Scutti, A L Matsuo, N O S Câmara, E G Rodrigues, L R Travassos
Silencing of SOCS1 protein with shRNAi lentivirus (shR-SOCS1) led to partial reversion of the tumorigenic phenotype of B16F10-Nex2 melanoma cells. SOCS1 silencing inhibited cell migration and invasion as well as in vitro growth by cell cycle arrest at S phase with increased cell size and nuclei. Down-regulation of SOCS1 decreased the expression of epidermal growth factor receptor, Ins-Rα, and fibroblast growth factor receptors. The present work aimed at analyzing the SOCS1 cell signaling and expression of proteins relevant to tumor development...
January 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28079028/observation-of-ultrasharp-metamagnetic-jumps-in-polycrystalline-er2cu2o5
#20
Anupam Banerjee, Jhuma Sannigrahi, Saurav Giri, Subham Majumdar
The observation of ultrasharp metamagnetic jumps in the field variation of magnetization ($M$ versus $H$) data of the highly insulating metal oxide Er$_2$Cu$_2$O$_5$ is investigated. The compound orders antiferromagnetically below about $T_{N1}$ = 28 K and shows conventional `not-so-sharp' metamagnetism around 13 kOe on the field increasing leg in the polycrystalline sample. The uniqueness of the ultrasharp jumps in Er$_2$Cu$_2$O$_5$ is that it is only observed in the field decreasing segment of the magnetization curve...
January 12, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
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