Read by QxMD icon Read

phase transition

Massimiliano de Zambotti, John Trinder, Ian M Colrain, Fiona C Baker
Insomnia is considered a hyperarousal disorder, in which several psychophysiological domains including the autonomic nervous system (ANS) are over-activated, potentially contributing to increased risk for cardiovascular (CV) disease. Here, we aimed to determine whether insomnia that develops in the context of the transition to menopause (menopausal transition insomnia, MTI) is similarly characterized by autonomic arousal. We also took into account modulation of the ANS by the hormonal changes of the menstrual cycle, a factor that has not previously been considered in studies on insomnia...
October 14, 2016: Psychoneuroendocrinology
Guillaume Martin, Lionel Roques
Various models describe asexual evolution by mutation, selection and drift. Some focus directly on fitness, typically modelling drift but ignoring or simplifying both epistasis and the distribution of mutation effects (travelling wave models). Others follow the dynamics of quantitative traits determining fitness (Fisher's geometrical model), imposing a complex but fixed form of mutation effects and epistasis, and often ignoring drift. In all cases, predictions are typically obtained in high or low mutation rate limits and for long-term stationary regimes, thus loosing information on transient behaviors and the effect of initial conditions...
October 21, 2016: Genetics
Eduardo Galdón, Marta Casas, Manuel Gayango, Isidoro Caraballo
The deep understanding of products and processes has become a requirement for pharmaceutical industries to follow the Quality by Design principles promoted by the regulatory authorities. With this aim, SeDeM expert system was developed as a useful preformulation tool to predict the likelihood to process drugs and excipients through direct compression. SeDeM system is a step forward in the rational development of a formulation, allowing the normalisation of the rheological parameters and the identification of the weaknesses and strengths of a powder or a powder blend...
October 18, 2016: European Journal of Pharmaceutics and Biopharmaceutics
Óscar J C Dias, Jorge E Santos, Benson Way
According to heuristic arguments, global AdS_{5}×S^{5} black holes are expected to undergo a phase transition in the microcanonical ensemble. At high energies, one expects black holes that respect the symmetries of the S^{5}; at low energies, one expects "localized" black holes that appear pointlike on the S^{5}. According to anti-de Sitter/conformal field theory correspondence, N=4 supersymmetric Yang-Mills (SYM) theory on a 3-sphere should therefore exhibit spontaneous R-symmetry breaking at strong coupling...
October 7, 2016: Physical Review Letters
B L Altshuler, E Cuevas, L B Ioffe, V E Kravtsov
We combine numerical diagonalization with semianalytical calculations to prove the existence of the intermediate nonergodic but delocalized phase in the Anderson model on disordered hierarchical lattices. We suggest a new generalized population dynamics that is able to detect the violation of ergodicity of the delocalized states within the Abou-Chakra, Anderson, and Thouless recursive scheme. This result is supplemented by statistics of random wave functions extracted from exact diagonalization of the Anderson model on ensemble of disordered random regular graphs (RRG) of N sites with the connectivity K=2...
October 7, 2016: Physical Review Letters
Yu-Zhi Sun, Bo Huang, Wei-Jian Xu, Dong-Dong Zhou, Shao-Li Chen, Shi-Yong Zhang, Zi-Yi Du, Yong-Rong Xie, Chun-Ting He, Wei-Xiong Zhang, Xiao-Ming Chen
Plastic crystals functioning with rotatable components offer new opportunities in areas such as modern optoelectronic materials. Here, by taking advantage of controllable rotation of the polar component within the ion-pair plastic-crystal system, we present two such crystals, namely, (Et4N)(CrO3X) (X = Cl or Br), which are unusual examples exhibiting two-staged thermosensitive dielectric responses above room temperature. The frequency-dependent response in the first stage is due to the structural phase transitions, whereas that in the second stage is induced by dynamic rotation of the polar halochromate anions in their NaCl-type plastic-crystal phases...
October 21, 2016: Inorganic Chemistry
P S Whitfield, N Herron, W E Guise, K Page, Y Q Cheng, I Milas, M K Crawford
We have examined the crystal structures and structural phase transitions of the deuterated, partially deuterated and hydrogenous organic-inorganic hybrid perovskite methyl ammonium lead iodide (MAPbI3) using time-of-flight neutron and synchrotron X-ray powder diffraction. Near 330 K the high temperature cubic phases transformed to a body-centered tetragonal phase. The variation of the order parameter Q for this transition scaled with temperature T as Q ∼ (Tc-T)(β), where Tc is the critical temperature and the exponent β was close to ¼, as predicted for a tricritical phase transition...
October 21, 2016: Scientific Reports
Alessandra Souza Barbosa, Filipe Ferreira da Silva, Andre Rebelo, Søren Vrønning Hoffmann, Marcio H F Bettega, Paulo Limao-Vieira
Here we report novel comprehensive investigations on the electronic state spectroscopies of isolated 2,4- and 2,6-difluorotoluene in the gas phase by high-resolution vacuum ultraviolet (VUV) photoabsorption measurements in the 4.4-10.8 eV energy-range, with absolute cross-section values derived. We also present the first set of ab initio calculations (vertical energies and oscillator strengths), which we have used in the assignment of valence transitions of the difluorotoluene molecules, together with calculated ionisation energies to obtain the Rydberg transitions for both molecules...
October 21, 2016: Journal of Physical Chemistry. A
Yu Sun, Jesper Østergaard
Efficient drug delivery is dependent on the drug substance dissolving in the body fluids, being released from dosage forms and transported to the site of action. A fundamental understanding of the interplay between the physicochemical properties of the active compound and pharmaceutical excipients defining formulation behavior after exposure to the aqueous environments and pharmaceutical performance is critical in pharmaceutical development, manufacturing and quality control of drugs. UV imaging has been explored as a tool for qualitative and quantitative characterization of drug dissolution and release with the characteristic feature of providing real-time visualization of the solution phase drug transport in the vicinity of the formulation...
October 20, 2016: Pharmaceutical Research
Bruno Cessac, Arnaud Le Ny, Eva Löcherbach
We initiate a mathematical analysis of hidden effects induced by binning spike trains of neurons. Assuming that the original spike train has been generated by a discrete Markov process, we show that binning generates a stochastic process that is no longer Markov but is instead a variable-length Markov chain (VLMC) with unbounded memory. We also show that the law of the binned raster is a Gibbs measure in the DLR (Dobrushin-Lanford-Ruelle) sense coined in mathematical statistical mechanics. This allows the derivation of several important consequences on statistical properties of binned spike trains...
October 20, 2016: Neural Computation
Thomas Burwick, Alexandros Bouras
The communication-through-coherence (CTC) hypothesis states that a sending group of neurons will have a particularly strong effect on a receiving group if both groups oscillate in a phase-locked ("coherent") manner (Fries, 2005, 2015). Here, we consider a situation with two visual stimuli, one in the focus of attention and the other distracting, resulting in two sites of excitation at an early cortical area that project to a common site in a next area. Taking a modeler's perspective, we confirm the workings of a mechanism that was proposed by Bosman et al...
October 20, 2016: Neural Computation
Mingyi Qu, Fang Fang, Xiaojing Zou, Quan Zeng, Zeng Fan, Lin Chen, Wen Yue, Xiaoyan Xie, Xuetao Pei
A better understanding of the mechanisms involved in megakaryocyte maturation will facilitate the generation of platelets in vitro and their clinical applications. A microRNA, miR-125b, has been suggested to have important roles in the self-renewal of megakaryocyte-erythroid progenitors and in platelet generation. However, miR-125b is also critical for hematopoietic stem cell self-renewal. Thus, the function of miR-125b and the complex signaling pathways regulating megakaryopoiesis remain to be elucidated. In this study, an attentive examination of the endogenous expression of miR-125b during megakaryocyte differentiation was performed...
October 20, 2016: Cell Death & Disease
Qiao-Li Lv, Yuan-Tao Huang, Gui-Hua Wang, Yan-Ling Liu, Jin Huang, Qiang Qu, Bao Sun, Lei Hu, Lin Cheng, Shu-Hui Chen, Hong-Hao Zhou
Emerging studies show that dysregulation of the receptor of activated protein kinase C1 (RACK1) plays a crucial role in tumorigenesis and progression of various cancers. However, the biological function and underlying mechanism of RACK1 in glioma remains poorly defined. Here, we found that RACK1 was significantly up-regulated in glioma tissues compared with normal brain tissues, being closely related to clinical stage of glioma both in mRNA and protein levels. Moreover, Kaplan-Meier analysis demonstrated that patients with high RACK1 expression had a poor prognosis (p = 0...
October 18, 2016: International Journal of Environmental Research and Public Health
Byeongchan Lee, Geun Woo Lee
Liquid-liquid transitions under high pressure are found in many elemental materials, but the transitions are known to be associated with either sp-valent materials or f-valent rare-earth elements, in which the maximum or a negative slope in the melting line is readily suggestive of the transition. Here we find a liquid-liquid transition with a positive melting slope in transition metal Ti from structural, electronic, and thermodynamic studies using ab-initio molecular dynamics calculations, showing diffusion anomaly, but no density anomaly...
October 20, 2016: Scientific Reports
W Knafo, F Duc, F Bourdarot, K Kuwahara, H Nojiri, D Aoki, J Billette, P Frings, X Tonon, E Lelièvre-Berna, J Flouquet, L-P Regnault
URu2Si2 is one of the most enigmatic strongly correlated electron systems and offers a fertile testing ground for new concepts in condensed matter science. In spite of >30 years of intense research, no consensus on the order parameter of its low-temperature hidden-order phase exists. A strong magnetic field transforms the hidden order into magnetically ordered phases, whose order parameter has also been defying experimental observation. Here, thanks to neutron diffraction under pulsed magnetic fields up to 40 T, we identify the field-induced phases of URu2Si2 as a spin-density-wave state...
October 20, 2016: Nature Communications
Laureano M Alarcón, M de Los Angeles Frías, Marcela A Morini, M Belén Sierra, Gustavo A Appignanesi, E Anibal Disalvo
We employ molecular dynamics simulations to study the hydration properties of Dipalmitoylphosphatidylcholine (DPPC) bilayers, both in the gel and the liquid crystalline states. We show that while the tight hydration centers (PO and CO moieties) are significantly hydrated in both phases, the gel-fluid transition involves significant changes at the second hydration shell, particularly at the buried region between the hydrocarbon tails. Thus, while almost no buried water population exists in the gel state below the carbonyls, this hydrophobic region becomes partially water accesible in the liquid crystalline state...
October 2016: European Physical Journal. E, Soft Matter
Olga Besharova, Verena M Suchanek, Raimo Hartmann, Knut Drescher, Victor Sourjik
Many bacteria primarily exist in nature as structured multicellular communities, so called biofilms. Biofilm formation is a highly regulated process that includes the transition from the motile planktonic to sessile biofilm lifestyle. Cellular differentiation within a biofilm is a commonly accepted concept but it remains largely unclear when, where and how exactly such differentiation arises. Here we used fluorescent transcriptional reporters to quantitatively analyze spatio-temporal expression patterns of several groups of genes during the formation of submerged Escherichia coli biofilms in an open static system...
2016: Frontiers in Microbiology
Jeroen Aerts, Annelies Laeremans, Laurens Minerva, Kurt Boonen, Budamgunta Harshavardhan, Rudi D'hooge, Dirk Valkenborg, Geert Baggerman, Lutgarde Arckens
The Morris water maze (MWM) spatial learning task has been demonstrated to involve a cognitive switch of action control to serve the transition from an early towards a late learning phase. However, the molecular mechanisms governing this switch are largely unknown. We employed MALDI MS imaging (MSI) to screen for changes in expression of small proteins in brain structures implicated in the different learning phases. We compared mice trained for 3days and 30days in the MWM, reflecting an early and a late learning phase in relation to the acquisition of a spatial learning task...
October 17, 2016: Biochimica et Biophysica Acta
Yan Suffren, Olivier Leynaud, Philippe Plaindoux, Alain Brenier, Isabelle Gautier-Luneau
The Ln(IO3)3(HIO3)y (y = 1 or 1.33) compounds are isostructural with the La(IO3)3(HIO3)y phases, but thermal studies reveal different behaviors. On the one hand, the partial thermal decompositions of these lanthanide compounds lead to the Ln(IO3)3 formulation, with a room temperature structure different from the β-La(IO3)3 obtained from La(IO3)3(HIO3)y. On the other hand, the partial thermal decompositions of the La1-xLnx(IO3)3(HIO3)y compounds prepared with lanthanides ions (Ce, Pr, Nd, Sm, Eu, Gd, and Yb) lead to acentric β-La1-xLnx(IO3)3...
October 19, 2016: Inorganic Chemistry
Janne Kalikka, Xilin Zhou, Jitendra Behera, Giacomo Nannicini, Robert E Simpson
We use an evolutionary algorithm to explore the design space of hexagonal Ge2Sb2Te5; a van der Waals layered two dimensional crystal heterostructure. The Ge2Sb2Te5 structure is more complicated than previously thought. Predominant features include layers of Ge3Sb2Te6 and Ge1Sb2Te4 two dimensional crystals that interact through Te-Te van der Waals bonds. Interestingly, (Ge/Sb)-Te-(Ge/Sb)-Te alternation is a common feature for the most stable structures of each generation's evolution. This emergent rule provides an important structural motif that must be included in the design of high performance Sb2Te3-GeTe van der Waals heterostructure superlattices with interfacial atomic switching capability...
October 19, 2016: Nanoscale
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"