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phase transition

Qiong Lou, Jun Wen, Yuanying Jiang, Jinghua Huang, Guorong Fan, Fenyun Song
A reliable liquid chromatography/tandem mass (LC-MS/MS) method was developed for quantitation of 3', 4'-dimethoxy flavonol-3-β-d-glucopyranoside (DF3G) in rat plasma using pantoprazole as the internal standard. An Agilent C18 column (100 mm × 3 mm, 3.5 μm) was performed for chromatographic separation with the mobile phase composed of methanol-water (containing formic acid) at a flow rate of 0.4 mL/min. A triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source in positive ion mode was applied to quantitative analysis by multiple reacting monitoring (MRM)...
April 7, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Nigel H Brookes
It is important to assess the viability of eye-banked corneas prior to transplantation due to inherent senescence and known loss of endothelial cells during surgical manipulation. Corneal endothelial cells have a complex basal and paracellular shape making them challenging to accurately measure, particularly in oedematous ex vivo tissue. This study used calibrated centroidal Voronoi Diagrams to segment cells in images of these human corneas, in order to characterize endothelial geometry, topology, and phase...
April 12, 2018: Experimental Eye Research
Ivan Netuka, Peter Ivák, Zuzana Tučanová, Stanislav Gregor, Ondrej Szárszoi, Poornima Sood, Daniel Crandall, Jessica Rimsans, Jean Marie Connors, Mandeep R Mehra
BACKGROUND: The HeartMate 3 left ventricular assist system is engineered to avoid pump thrombosis, yet bleeding complications persist. We investigated the safety of low-intensity anti-coagulation in patients with the HeartMate 3. METHODS: The Minimal AnticoaGulation EvaluatioNTo aUgment heMocompatibility (MAGENTUM 1) pilot study is a prospective, single-arm study of low-intensity warfarin anti-coagulation in patients implanted with the HeartMate 3 pump. After standard warfarin anti-coagulation (international normalized ratio [INR] 2...
March 27, 2018: Journal of Heart and Lung Transplantation
Nhan C Dang, Jennifer A Ciezak-Jenkins
In this work, the dependence of the morphology and stability of the extended solid of carbon monoxide (CO) is correlated to the rate of transformation from the molecular CO to extended solid of CO using optical imaging, photoluminescence, Raman spectroscopy, and X-ray diffraction. The analyses show the rate and pressure of the transformation to be strongly controlled by catalytic effects, both chemical and optical. In a larger volume per reaction area, the transformation was found to require either a longer time at an elevated pressure or a higher pressure compared to a sample synthesized in a smaller volume per reaction area, leading to the conclusion that the transformation rate is slower for a sample in a larger volume per reaction area...
April 14, 2018: Journal of Chemical Physics
Edgar A Engel
The ferroelectric to paraelectric (PE) phase transition of KH2 PO4 (KDP) is investigated as a stringent test of the first-principles, normal modes framework proposed for calculating anharmonic quantum nuclear motion. Accurate spatially resolved momentum distribution functions (MDFs) are directly calculated from the nuclear wavefunction, overcoming the limitations of path-integral molecular dynamics methods. They indicate coherent, correlated tunneling of protons across hydrogen bonds in the PE phase in agreement with neutron Compton scattering data and reproduces the key features of the experimental MDF...
April 14, 2018: Journal of Chemical Physics
Anna Powers, Yohann Scribano, David Lauvergnat, Elsy Mebe, David M Benoit, Zlatko Bačić
We report a theoretical study of the frequency shift (redshift) of the stretching fundamental transition of an H2 molecule confined inside the small dodecahedral cage of the structure II clathrate hydrate and its dependence on the condensed-phase environment. In order to determine how much the hydrate water molecules beyond the confining small cage contribute to the vibrational frequency shift, quantum five-dimensional (5D) calculations of the coupled translation-rotation eigenstates are performed for H2 in the v=0 and v=1 vibrational states inside spherical clathrate hydrate domains of increasing radius and a growing number of water molecules, ranging from 20 for the isolated small cage to over 1900...
April 14, 2018: Journal of Chemical Physics
C I León-Pimentel, J I Amaro-Estrada, J Hernández-Cobos, H Saint-Martin, A Ramírez-Solís
The hydration features of [Mg(H2 O)n ]2+ and [Ca(H2 O)n ]2+ clusters with n = 3-6, 8, 18, and 27 were studied by means of Born-Oppenheimer molecular dynamics simulations at the B3LYP/6-31+G** level of theory. For both ions, it is energetically more favorable to have all water molecules in the first hydration shell when n ≤ 6, but stable lower coordination average structures with one water molecule not directly interacting with the ion were found for Mg2+ at room temperature, showing signatures of proton transfer events for the smaller cation but not for the larger one...
April 14, 2018: Journal of Chemical Physics
Xiaoyan Qi, Lin Zhao, Qiuping Zhao, Qiaoxia Xu
In this study, a fast, simple and sensitive liquid chromatography-mass spectrometry method was developed for simultaneous determination of crizotinib and its major oxidative metabolite crizotinib-lactam in human plasma. The plasma samples were deproteinated by using acetonitrile containing 0.1% formic acid as precipitant whereas the chromatographic separation was obtained on a C18 column with 0.1% formic acid aqueous and acetonitrile/methanol (v:v, 1:1) as mobile phase. The mass detector was operated in positive selected reaction monitoring mode...
March 28, 2018: Journal of Pharmaceutical and Biomedical Analysis
Andrés M Tibabuzo Perdomo, Erik M Alberts, Stephen D Taylor, Debra M Sherman, Chia-Ping Huang, Jonathan J Wilker
Oysters construct extensive reef communities, providing food, protection from storms, and healthy coastlines. We still do not have a clear picture of how these animals attach to surfaces. Efforts described herein provide the first examination of adhesion at the transition from free swimming larvae to initial substrate attachment, through meta- morphosis, and on to adulthood. Two different bonding systems were found to coexist. Larvae use an organic, hydrated glue that persists while the animal progresses into the juvenile phase, at which point a very different adhesive emerges...
April 13, 2018: ACS Applied Materials & Interfaces
Gauri M Nabar, Jessica O Winter, Barbara E Wyslouzil
The interfacial instability method has emerged as a viable approach for encapsulating high concentrations of nanoparticles (NPs) within morphologically diverse micelles. In this method, transient interfacial instabilities at the surface of an emulsion droplet guide self-assembly of block co-polymers and NP encapsulants. Although used by many groups, there are no systematic investigations exploring the relationship between NP properties and micelle morphology. Here, the effect of quantum dot (QD) and superparamagnetic iron oxide NP (SPION) concentration on the shape, size, and surface deformation of initially spherical poly(styrene-b-ethylene oxide) (PS-b-PEO) micelles was examined...
April 13, 2018: Soft Matter
Jize Sui, Yiming Ding, Masao Doi
When a suspension of platelet-like particles sediment in a closed container, the particles undergo isotropic-nematic phase transition (I-N transition), and there appears a clear interface between the isotropic phase and the nematic phase. Usually the interface moves from bottom to top since the nematic phase appears and grows at the bottom, but it has been observed that in some situations the interface moves from top to bottom. Here, we study the dynamics of the interface by solving the non-equilibrium diffusion equation for the concentration of platelet-like particles, and show that the I-N interface can move upward (rising interface) or downward (falling interface) depending on whether the initial concentration is less than the critical concentration of I-N transition or more than it...
April 13, 2018: Soft Matter
Hailin Tang, Yuan Guo, Li Peng, Hui Fang, Zhigang Wang, Yuanyi Zheng, Haitao Ran, Yu Chen
As one of the most representative non-invasive therapeutic modalities, high-intensity focused ultrasound (HIFU) has shown the great promise for cancer therapy, but its low therapeutic efficacy and biosafety significantly hinder the further extensive clinical translation and application. In this work, we report on the construction of a multifunctional theranostic nanoplatform to synergistically enhance the HIFU-therapeutic efficacy based on nanomedicine. A targeted and temperature-responsive theranostic nanoplatform (PFH/DOX@PLGA/Fe3O4-FA) has been designed and fabricated for efficient ultrasound/magnetic resonance dual-modality imaging-guided HIFU/chemo synergistic therapy...
April 13, 2018: ACS Applied Materials & Interfaces
Imam Makhfudz
We propose in this work an effective field theory description of the chiral spin liquid state in Heisenberg spin system on kagom\'{e} lattice.To this end, we derive the low-energy effective theory of kagom\'{e} (isotropic) Heisenberg antiferromagnet around its ordered ground states found numerically and show that quantum fluctuations induced by further neighbor spin exchanges are equally strong as those from first neighbor.We use a chiral order parameter theory to argue for the occurrence of finite temperature chiral symmetry breaking transition into chiral ordered state in kagom\'{e} antiferromagnet with further neighbor spin exchange interactions...
April 13, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Susanne Stemmer, S James Allen
Understanding the anomalous transport properties of strongly correlated materials is one of the most formidable challenges in condensed matter physics. For example, one encounters metal-insulator transitions, deviations from Landau Fermi liquid behavior, longitudinal and Hall scattering rate separation, a pseudogap phase, and bad metal behavior. These properties have been studied extensively in bulk materials, such as the unconventional superconductors and heavy fermion systems. Oxide heterostructures have recently emerged as new platforms to probe, control, and understand strong correlation phenomena...
April 13, 2018: Reports on Progress in Physics
Y R Guo, F Dong, C Qiao, J J Wang, S Y Wang, Ming Xu, Y X Zheng, R J Zhang, L Y Chen, C Z Wang, K M Ho
Crystalline Sb2Te3 is widely studied due to its important applications in memory materials and topological insulators. The liquid and amorphous structures of this compound as well as the dynamics upon quenching, however, are yet to be fully understood. In this work, we have systematically studied the dynamical properties and local structure of Sb2Te3 at different temperatures using ab initio molecular dynamics simulations. The calculated structure factors agree well with the experimental results. The atomic number density and mean-squared displacement as a function of temperature clearly indicate three states as the temperature decreases, namely, melt, undercooled liquid and glass state, respectively...
April 13, 2018: Physical Chemistry Chemical Physics: PCCP
Kıvanç Esat, Grégory David, Theodoros Poulkas, Mikhail Shein, Ruth Signorell
Fast dynamics (down to 10 ms) during exposure to changing relative humidity of single optically trapped K2CO3 particles were observed in the submicron to micron size range with time-resolved broadband light scattering and Raman spectroscopy. The study shows that complex multiple processes accompany efflorescence and deliquescence of unsupported aerosol particles. Efflorescence can occur in a single process in less than 10 ms (prompt) or proceed via multiple successive processes (multistep) that can last up to more than 10 seconds...
April 13, 2018: Physical Chemistry Chemical Physics: PCCP
Kang Li, Xiao-Xue Yuan, He-Min Sun, Long-Sheng Zhao, Ruocong Tang, Zhi-Hua Chen, Qi-Long Qin, Xiu-Lan Chen, Yu-Zhong Zhang, Hai-Nan Su
Peptidoglycan is the fundamental structural constituent of the bacterial cell wall. Despite many years of research, the architecture of peptidoglycan is still largely elusive. Here, we report the high-resolution architecture of peptidoglycan from the model Gram-positive bacterium Bacillus subtilis . We provide high-resolution evidence of peptidoglycan architecture remodeling at different growth stages. Side wall peptidoglycan from B. subtilis strain AS1.398 changed from an irregular architecture in exponential growth phase to an ordered cable-like architecture in stationary phase...
2018: Frontiers in Microbiology
Claire L Hobday, Christopher H Woodall, Matthew J Lennox, Mungo Frost, Konstantin Kamenev, Tina Düren, Carole A Morrison, Stephen A Moggach
Some porous crystalline solids change their structure upon guest inclusion. Unlocking the potential of these solids for a wide variety of applications requires full characterisation of the response to adsorption and the underlying framework-guest interactions. Here, we introduce an approach to understanding gas uptake in porous metal-organic frameworks (MOFs) by loading liquefied gases at GPa pressures inside the Zn-based framework ZIF-8. An integrated experimental and computational study using high-pressure crystallography, grand canonical Monte Carlo (GCMC) and periodic DFT simulations has revealed six symmetry-independent adsorption sites within the framework and a transition to a high-pressure phase...
April 12, 2018: Nature Communications
Satomi Konno, Hamae Nagai
We conducted questionnaire surveys focusing on the"actual situation of cooperation between discharge nurses and homevisiting nurses etc. from transition to home-care through the terminal phase in terminal cancer patients."As a result,discharge nurses were employed at acute-stage hospitals to practice discharge adjustment. Medical staff in home care and home care workers continuously supported the patients and their families in managing difficulties such as changes in pathological conditions and care-related anxiety after the patient was discharged...
March 2018: Gan to Kagaku Ryoho. Cancer & Chemotherapy
Shovamayee Maharana, Jie Wang, Dimitrios K Papadopoulos, Doris Richter, Andrey Pozniakovsky, Ina Poser, Marc Bickle, Sandra Rizk, Jordina Guillén-Boixet, Titus Franzmann, Marcus Jahnel, Lara Marrone, Young-Tae Chang, Jared Sterneckert, Pavel Tomancak, Anthony A Hyman, Simon Alberti
Prion-like RNA binding proteins (RBPs) such as TDP-43 or FUS are largely soluble in the nucleus, but form solid pathological aggregates when mislocalized to the cytoplasm. What keeps these proteins soluble in the nucleus and promotes aggregation in the cytoplasm is still unknown. We report here that RNA critically regulates the phase behavior of prion-like RBPs. Low RNA/protein ratios promote phase separation into liquid droplets, whereas high ratios prevent droplet formation in vitro. Reduction of nuclear RNA levels or genetic ablation of RNA binding causes excessive phase separation and the formation of cytotoxic solid-like assemblies in cells...
April 12, 2018: Science
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