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https://www.readbyqxmd.com/read/28637301/eden-evolutionary-dynamics-within-environments
#1
Philipp C Münch, Bärbel Stecher, Alice C McHardy
Summary: Metagenomics revolutionized the field of microbial ecology, giving access to Gb-sized datasets of microbial communities under natural conditions. This enables fine-grained analyses of the functions of community members, studies of their association with phenotypes and environments, as well as of their microevolution and adaptation to changing environmental conditions. However, phylogenetic methods for studying adaptation and evolutionary dynamics are not able to cope with big data...
June 16, 2017: Bioinformatics
https://www.readbyqxmd.com/read/28636959/the-enteric-network-interactions-between-the-immune-and-nervous-systems-of-the-gut
#2
REVIEW
Bryan B Yoo, Sarkis K Mazmanian
Interactions between the nervous and immune systems enable the gut to respond to the variety of dietary products that it absorbs, the broad spectrum of pathogens that it encounters, and the diverse microbiome that it harbors. The enteric nervous system (ENS) senses and reacts to the dynamic ecosystem of the gastrointestinal (GI) tract by translating chemical cues from the environment into neuronal impulses that propagate throughout the gut and into other organs in the body, including the central nervous system (CNS)...
June 20, 2017: Immunity
https://www.readbyqxmd.com/read/28636824/bicanonical-ab-initio-molecular-dynamics-for-open-systems
#3
Johannes Frenzel, Bernd Meyer, Dominik Marx
Performing ab initio molecular dynamics simulations of open systems, where the chemical potential rather than the number of both, nuclei and electrons is fixed, still is a challenge. Here, drawing on bicanonical sampling ideas introduced two decades ago by Swope and Andersen to calculate chemical potentials of liquids and solids, an ab initio simulation technique is devised, which introduces a fictitious dynamics of two superimposed but otherwise independent periodic systems including full electronic structure, such that either the chemical potential or the average fractional particle number of a specific chemical species can be kept constant...
June 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28636820/experimental-and-theoretical-study-of-ionic-pair-dissociation-in-lithium-ion-linear-polyethyleneimine-polyacrylonitrile-blend-for-solid-polymer-electrolytes
#4
Fernando Pignanelli, Mariano Romero, Ricardo Faccio, Álvaro W Mombrú
Herein, we report the preparation and characterization of novel polymeric blend between linear polyethylene imine (PEI) and polyacrylonitrile (PAN), with the purpose to facilitate the dissociation of lithium perchlorate salt (LiClO4) and thus to enhance Li-ion transport. It is a joint theoretical and experimental procedure for evaluating and thus demonstrating, the lithium salt dissociation. The procedure implies the correlation between theoretical pair distribution function (PDF) and conventional X-rays diffraction (XRD) by means of molecular dynamics (MD) approach...
June 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28636793/development-and-validation-of-ihs4-a-novel-dynamic-scoring-system-to-assess-hidradenitis-suppurativa-acne-inversa-severity
#5
C C Zouboulis, T Tzellos, A Kyrgidis, G B E Jemec, F G Bechara, E J Giamarellos-Bourboulis, J R Ingram, T Kanni, I Karagiannidis, A Martorell, Ł Matusiak, A Pinter, E P Prens, D Presser, S Schneider-Burrus, E von Stebut, J C Szepietowski, H H van der Zee, S M Wilden, R Sabat
BACKGROUND: A validated tool for the dynamic severity assessment of hidradenitis suppurativa (HS) is lacking. The aim of this study was to develop and validate such a novel scoring system. METHODS: A Delphi voting procedure was conducted among the members of the European Hidradenitis Suppurativa Foundation (EHSF) to achieve consensus towards an initial HS Severity Score System (HS4). Strengths and weaknesses of HS4 were examined by a multicenter prospective study...
June 21, 2017: British Journal of Dermatology
https://www.readbyqxmd.com/read/28636679/towards-the-analysis-of-attosecond-dynamics-in-complex-systems
#6
C-Z Gao, P M Dinh, P-G Reinhard, E Suraud
We study from a theoretical perspective the ionization of molecules and clusters induced by irradiation of a combined two-color laser field consisting of a train of attosecond XUV pulses in the presence of an IR field. We use time-dependent density-functional theory (TDDFT) in real time and real space as a theoretical tool. The calculated results are compared to experimental data when available. We also compare TDDFT with results obtained using a time-dependent Schrödinger equation (TDSE), which is well suited to simple systems while TDDFT allows dealing with more complex molecules and clusters...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28636625/comparison-study-of-exhaust-plume-impingement-effects-of-small-mono-and-bipropellant-thrusters-using-parallelized-dsmc-method
#7
Kyun Ho Lee
A space propulsion system is important for the normal mission operations of a spacecraft by adjusting its attitude and maneuver. Generally, a mono- and a bipropellant thruster have been mainly used for low thrust liquid rocket engines. But as the plume gas expelled from these small thrusters diffuses freely in a vacuum space along all directions, unwanted effects due to the plume collision onto the spacecraft surfaces can dramatically cause a deterioration of the function and performance of a spacecraft. Thus, aim of the present study is to investigate and compare the major differences of the plume gas impingement effects quantitatively between the small mono- and bipropellant thrusters using the computational fluid dynamics (CFD)...
2017: PloS One
https://www.readbyqxmd.com/read/28636597/phase-separation-drives-heterochromatin-domain-formation
#8
Amy R Strom, Alexander V Emelyanov, Mustafa Mir, Dmitry V Fyodorov, Xavier Darzacq, Gary H Karpen
Constitutive heterochromatin is an important component of eukaryotic genomes that has essential roles in nuclear architecture, DNA repair and genome stability, and silencing of transposon and gene expression. Heterochromatin is highly enriched for repetitive sequences, and is defined epigenetically by methylation of histone H3 at lysine 9 and recruitment of its binding partner heterochromatin protein 1 (HP1). A prevalent view of heterochromatic silencing is that these and associated factors lead to chromatin compaction, resulting in steric exclusion of regulatory proteins such as RNA polymerase from the underlying DNA...
June 21, 2017: Nature
https://www.readbyqxmd.com/read/28636369/dynamics-of-charged-species-in-ionic-neutral-block-copolymer-and-surfactant-complexes
#9
Jose M Borreguero, Philip A Pincus, Bobby G Sumpter, Monojoy Goswami
Structure-property relationships of ionic block copolymer (BCP) surfactant complexes are critical towards the progress of favorable engineering design of efficient charge transport materials. In this article, molecular dynamics simulations are used to understand the dynamics of charge-neutral BCP and surfactant complexes. The dynamics are examined for two different systems, charged-neutral double hydrophilic and hydrophobic-hydrophilic block copolymers with oppositely charged surfactant moieties. The dynamics of the surfactant head, tails and charges are studied for five different BCP volume fractions...
June 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28636349/water-dynamics-from-the-surface-to-the-interior-of-a-supramolecular-nanostructure
#10
Julia H Ortony, Baofu Qiao, Christina J Newcomb, Timothy J Keller, Liam C Palmer, Elad Deiss-Yehiely, Monica Olvera de la Cruz, Songi Han, Samuel I Stupp
Water within and surrounding the structure of a biological system adopts context-specific dynamics that mediate virtually all of the events involved in the inner workings of a cell. These events range from protein folding and molecular recognition to the formation of hierarchical structures. Water dynamics are mediated by the chemistry and geometry of interfaces where water and biomolecules meet. Here we investigate experimentally and computationally the translational dynamics of vicinal water molecules within the volume of a supramolecular peptide nanofiber measuring 6...
June 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28636323/ultrafast-dynamic-pressure-sensors-based-on-graphene-hybrid-structure
#11
Shanbiao Liu, Xing Wu, Dongdong Zhang, Congwei Guo, Peng Wang, Weida Hu, Xinming Li, Xiaofeng Zhou, Hejun Xu, Chen Luo, Jian Zhang, Jun-Hao Chu
The development of artificial skin is drawing tremendous attention due to its potential applications in sensing a variety of physical quantities, such as tactility, vibration, and temperature. A strain sensor that can mimic and surpass the subtle pressure-sensing properties of natural skin requires rational material design and array-accessible devices. Here, we report a new and facile preparation of a graphene hybrid structure with an ultrafast dynamic pressure response. Graphene oxide nanosheets are used as a surfactant to prevent graphene restacking in aqueous solution...
June 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28636088/multicompartment-drug-release-system-for-dynamic-modulation-of-tissue-responses
#12
Aaron H Morris, Rajwant S Mahal, Jillian Udell, Michelle Wu, Themis R Kyriakides
Pharmacological modulation of responses to injury is complicated by the need to deliver multiple drugs with spatiotemporal resolution. Here, a novel controlled delivery system containing three separate compartments with each releasing its contents over different timescales is fabricated. Core-shell electrospun fibers create two of the compartments in the system, while electrosprayed spheres create the third. Utility is demonstrated by targeting the foreign body response to implants because it is a dynamic process resulting in implant failure...
June 21, 2017: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/28636032/reline-aqueous-solutions-behaving-as-liquid-mixtures-of-h-bonded-co-solvents-microphase-segregation-and-formation-of-co-continuous-structures-as-indicated-by-brillouin-and-1-h-nmr-spectroscopies
#13
E Posada, N López-Salas, R J Jiménez Riobóo, M L Ferrer, M C Gutiérrez, F Del Monte
Deep eutectic solvents (DESs) offer a suitable alternative to conventional solvents in terms of both performance and cost-effectiveness. Some DESs also offer certain green features, the greenness of which is notoriously enhanced when combined with water. Aqueous DES dilutions are therefore attracting great attention as a novel green medium for biotechnological processes, with the aqueous dilutions of reline - a DES composed of urea and choline chloride - being one of the most studied systems. Despite their macroscopic homogeneous appearance, both (1)H NMR spectroscopic studies and molecular dynamics simulations have revealed the occurrence of certain dynamic heterogeneity at a microscopic molecular level...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28636028/supramolecular-functional-assemblies-dynamic-membrane-transporters-and-peptide-nanotubular-composites
#14
Alberto Fuertes, Marisa Juanes, Juan R Granja, Javier Montenegro
The fabrication of functional molecular devices constitutes one of the most important current challenges for chemical sciences. The complex processes accomplished by living systems continuously demand the assistance of non-covalent interactions between molecular building blocks. Additionally, these building blocks (proteins, membranes, nucleotides) are also constituted by self-assembled structures. Therefore, supramolecular chemistry is the discipline required to understand the properties of the minimal self-assembled building blocks of living systems and to develop new functional smart materials...
June 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28634724/darma-software-for-dual-axis-rating-and-media-annotation
#15
Jeffrey M Girard, Aidan G C Wright
Continuous measurement systems provide a means of measuring dynamic behavioral and experiential processes as they play out over time. DARMA is a modernized continuous measurement system that synchronizes media playback and the continuous recording of two-dimensional measurements. These measurements can be observational or self-reported and are provided in real-time through the manipulation of a computer joystick. DARMA also provides tools for reviewing and comparing collected measurements and for customizing various settings...
June 20, 2017: Behavior Research Methods
https://www.readbyqxmd.com/read/28634602/recent-advances-in-the-computational-chemistry-of-soft-porous-crystals
#16
Guillaume Fraux, François-Xavier Coudert
Here we highlight recent progress in the field of computational chemistry of nanoporous materials, focusing on methods and studies that address the extraordinary dynamic nature of these systems: the high flexibility of their frameworks, the large-scale structural changes upon external physical or chemical stimulation, and the presence of defects and disorder. The wide variety of behavior demonstrated in soft porous crystals, including the topical class of metal-organic frameworks, opens new challenges for computational chemistry methods at all scales...
June 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28634596/study-on-drive-system-of-hybrid-tree-harvester
#17
Shen Rong-Feng, Zhang Xiaozhen, Zhou Chengjun
Hybrid tree harvester with a 60 kW diesel engine combined with a battery pile could be a "green" forest harvesting and transportation system. With the new design, the diesel engine maintains a constant engine speed, keeping fuel consumption low while charging the batteries that drive the forwarder. As an additional energy saving method, the electric motors work as generators to charge the battery pile when the vehicle moves downhill. The vehicle is equipped with six large wheels providing high clearance over uneven terrain while reducing ground pressure...
2017: TheScientificWorldJournal
https://www.readbyqxmd.com/read/28634476/changes-in-n-p-supply-ratios-affect-the-ecological-stoichiometry-of-a-toxic-cyanobacterium-and-its-fungal-parasite
#18
Thijs Frenken, Joren Wierenga, Alena S Gsell, Ellen van Donk, Thomas Rohrlack, Dedmer B Van de Waal
Human activities have dramatically altered nutrient fluxes from the landscape into receiving waters. As a result, not only the concentration of nutrients in surface waters has increased, but also their elemental ratios have changed. Such shifts in resource supply ratios will alter autotroph stoichiometry, which may in turn have consequences for higher trophic levels, including parasites. Here, we hypothesize that parasite elemental composition will follow changes in the stoichiometry of its host, and that its reproductive success will decrease with host nutrient limitation...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28634369/forecasting-effusive-dynamics-and-decompression-rates-by-magmastatic-model-at-open-vent-volcanoes
#19
Maurizio Ripepe, Marco Pistolesi, Diego Coppola, Dario Delle Donne, Riccardo Genco, Giorgio Lacanna, Marco Laiolo, Emanuele Marchetti, Giacomo Ulivieri, Sébastien Valade
Effusive eruptions at open-conduit volcanoes are interpreted as reactions to a disequilibrium induced by the increase in magma supply. By comparing four of the most recent effusive eruptions at Stromboli volcano (Italy), we show how the volumes of lava discharged during each eruption are linearly correlated to the topographic positions of the effusive vents. This correlation cannot be explained by an excess of pressure within a deep magma chamber and raises questions about the actual contributions of deep magma dynamics...
June 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28634341/terahertz-circular-airy-vortex-beams
#20
Changming Liu, Jinsong Liu, Liting Niu, Xuli Wei, Kejia Wang, Zhengang Yang
Vortex beams have received considerable research interests both in optical and millimeter-wave domain since its potential to be utilized in the wireless communications and novel imaging systems. Many well-known optical beams have been demonstrated to carry orbital angular momentum (OAM), such as Laguerre-Gaussian beams and high-order Bessel beams. Recently, the radially symmetric Airy beams that exhibit an abruptly autofocusing feature are also demonstrated to be capable of carrying OAM in the optical domain...
June 20, 2017: Scientific Reports
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