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https://www.readbyqxmd.com/read/29334362/investigation-of-resistance-switching-in-siox-rram-cells-using-a-3d-multi-scale-kinetic-monte-carlo-simulator
#1
Toufik Sadi, Adnan Mehonic, Luca Montesi, Mark Buckwell, Anthony Kenyon, Asen Asenov
We employ an advanced three-dimensional (3D) electro-thermal simulator to explore the physics and potential of oxide-based resistive random-access memory (RRAM) cells. The physical simulation model has been developed recently, and couples a kinetic Monte Carlo study of electron and ionic transport to the self-heating phenomenon while accounting carefully for the physics of vacancy generation and recombination, and trapping mechanisms. The simulation framework successfully captures resistance switching, including the electroforming, set and reset processes, by modeling the dynamics of conductive filaments in the 3D space...
January 15, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29334340/identification-of-anti-filarial-leads-against-aspartate-semialdehyde-dehydrogenase-of-wolbachia-endosymbiont-of-brugia-malayi-combined-molecular-docking-and-molecular-dynamics-approaches
#2
Dhamodharan Prabhu, Sundaraj Rajamanikandan, Mathimaran Amala, Surekha Kanagarajan, Jeyaraman Jeyakanthan
Lymphatic filariasis is a debilitating vector borne parasitic disease that infects human lymphatic system by nematode Brugia malayi. Currently available anti-filarial drugs are effective only on the larval stages of parasite. So far, no effective drugs are available for humans to treat filarial infections. In this regard, aspartate semialdehyde dehydrogenase (ASDase) in lysine biosynthetic pathway from Wolbachia endosymbiont Brugia malayi represents an attractive therapeutic target for the development of novel anti-filarial agents...
January 15, 2018: Journal of Biomolecular Structure & Dynamics
https://www.readbyqxmd.com/read/29334298/long-term-effects-of-tungsten-carbide-wc-nanoparticles-in-pelagic-and-benthic-aquatic-ecosystems
#3
Mikael T Ekvall, Jonas Hedberg, Inger Odnevall Wallinder, Lars-Anders Hansson, Tommy Cedervall
As the production and usage of nanomaterials are increasing so are the concerns related to the release of the material into nature. Tungsten carbide (WC) is widely used for its hard metal properties, although its use, in for instance tyre studs, may result in nano-sized particles ending up in nature. Here, we evaluate the potential long-term exposure effects of WC nanoparticles on a pelagic (Daphnia magna) and a benthic (Asellus aquaticus) organism. No long-term effects were observed in the benthic system with respect to population dynamics or ecosystem services...
January 15, 2018: Nanotoxicology
https://www.readbyqxmd.com/read/29333924/dynamic-mr-imaging-for-functional-vascularization-depends-on-tissue-factor-signaling-in-glioblastoma
#4
Xiao Chen, Tian Xie, Jingqin Fang, Wei Xue, Houyi Kang, Haipeng Tong, Yu Guo, Bo Zhang, Sumei Wang, Yizeng Yang, Weiguo Zhang
Glomeruloid vascular proliferation (GVP) is a diagnostic hallmark and links to aggressive behavior, therapy resistance and poor prognosis in glioblastoma (GBM). It lacks clinical approaches to predict and monitor its formation and dynamic change. Yet the mechanism of GVPs also remains largely unknown. Using an in situ GBM xenograft mouse model, combined clinical MRI images of pre-surgery tumor and pathological investigation, we demonstrated that the inhibition of tissue factor (TF) decreased GVPs in Mouse GBM xenograft model...
January 15, 2018: Cancer Biology & Therapy
https://www.readbyqxmd.com/read/29333753/comparative-performance-of-different-scale-down-simulators-of-substrate-gradients-in-penicillium-chrysogenum-cultures-the-need-of-a-biological-systems-response-analysis
#5
Guan Wang, Junfei Zhao, Cees Haringa, Wenjun Tang, Jianye Xia, Ju Chu, Yingping Zhuang, Siliang Zhang, Amit T Deshmukh, Walter van Gulik, Joseph J Heijnen, Henk J Noorman
In a 54 m3 large-scale penicillin fermentor, the cells experience substrate gradient cycles at the timescales of global mixing time about 20-40 s. Here, we used an intermittent feeding regime (IFR) and a two-compartment reactor (TCR) to mimic these substrate gradients at laboratory-scale continuous cultures. The IFR was applied to simulate substrate dynamics experienced by the cells at full scale at timescales of tens of seconds to minutes (30 s, 3 min and 6 min), while the TCR was designed to simulate substrate gradients at an applied mean residence time (τc) of 6 min...
January 15, 2018: Microbial Biotechnology
https://www.readbyqxmd.com/read/29333735/hot-electron-assisted-femtosecond-all-optical-modulation-in-plasmonics
#6
Mohammad Taghinejad, Hossein Taghinejad, Zihao Xu, Yawei Liu, Sean P Rodrigues, Kyu-Tae Lee, Tianquan Lian, Ali Adibi, Wenshan Cai
The optical Kerr nonlinearity of plasmonic metals provides enticing prospects for developing reconfigurable and ultracompact all-optical modulators. In nanostructured metals, the coherent coupling of light energy to plasmon resonances creates a nonequilibrium electron distribution at an elevated electron temperature that gives rise to significant Kerr optical nonlinearities. Although enhanced nonlinear responses of metals facilitate the realization of efficient modulation devices, the intrinsically slow relaxation dynamics of the photoexcited carriers, primarily governed by electron-phonon interactions, impedes ultrafast all-optical modulation...
January 15, 2018: Advanced Materials
https://www.readbyqxmd.com/read/29333491/multifunctional-bioreactor-system-for-human-intestine-tissues
#7
Wenda Zhou, Ying Chen, Terrence Roh, Yinan Lin, Shengjie Ling, Siwei Zhao, James D Lin, Noor Khalil, Dana M Cairns, Eleana Manousiouthakis, Megan Tse, David L Kaplan
The three-dimensional (3D) cultivation of intestinal cells and tissues in dynamic bioreactor systems to represent in vivo intestinal microenvironments is essential for developing regenerative medicine treatments for intestinal diseases. We have previously developed in vitro human intestinal tissue systems using a 3D porous silk scaffold system with intestinal architectures and topographical features for the adhesion, growth, and differentiation of intestinal cells under static culture conditions. In this study, we designed and fabricated a multifunctional bioreactor system that incorporates pre-epithelialized 3D silk scaffolds in a dynamic culture environment for in vitro engineering of human intestine tissues...
January 8, 2018: ACS Biomaterials Science & Engineering
https://www.readbyqxmd.com/read/29333473/charge-migration-and-charge-transfer-in-molecular-systems
#8
REVIEW
Hans Jakob Wörner, Christopher A Arrell, Natalie Banerji, Andrea Cannizzo, Majed Chergui, Akshaya K Das, Peter Hamm, Ursula Keller, Peter M Kraus, Elisa Liberatore, Pablo Lopez-Tarifa, Matteo Lucchini, Markus Meuwly, Chris Milne, Jacques-E Moser, Ursula Rothlisberger, Grigory Smolentsev, Joël Teuscher, Jeroen A van Bokhoven, Oliver Wenger
The transfer of charge at the molecular level plays a fundamental role in many areas of chemistry, physics, biology and materials science. Today, more than 60 years after the seminal work of R. A. Marcus, charge transfer is still a very active field of research. An important recent impetus comes from the ability to resolve ever faster temporal events, down to the attosecond time scale. Such a high temporal resolution now offers the possibility to unravel the most elementary quantum dynamics of both electrons and nuclei that participate in the complex process of charge transfer...
November 2017: Structural Dynamics (Melville, N.Y.)
https://www.readbyqxmd.com/read/29333205/high-aspect-ratio-induced-spontaneous-generation-of-monodisperse-picolitre-droplets-for-digital-pcr
#9
Xiaonan Xu, Haojun Yuan, Ruyuan Song, Miao Yu, Ho Yin Chung, Youmin Hou, Yuhe Shang, Hongbo Zhou, Shuhuai Yao
Droplet microfluidics, which involves micrometer-sized emulsion droplets on a microfabricated platform, has been demonstrated as a unique system for many biological and chemical applications. Robust and scalable generation of monodisperse droplets at high throughput is of fundamental importance for droplet microfluidics. Classic designs for droplet generation employ shear fluid dynamics to induce the breakup of droplets in a two-phase flow and the droplet size is sensitive to flow rate fluctuations, often resulting in polydispersity...
January 2018: Biomicrofluidics
https://www.readbyqxmd.com/read/29332945/the-human-skin-microbiome
#10
REVIEW
Allyson L Byrd, Yasmine Belkaid, Julia A Segre
Functioning as the exterior interface of the human body with the environment, skin acts as a physical barrier to prevent the invasion of foreign pathogens while providing a home to the commensal microbiota. The harsh physical landscape of skin, particularly the desiccated, nutrient-poor, acidic environment, also contributes to the adversity that pathogens face when colonizing human skin. Despite this, the skin is colonized by a diverse microbiota. In this Review, we describe amplicon and shotgun metagenomic DNA sequencing studies that have been used to assess the taxonomic diversity of microorganisms that are associated with skin from the kingdom to the strain level...
January 15, 2018: Nature Reviews. Microbiology
https://www.readbyqxmd.com/read/29332602/nanoemulsion-strategy-for-ursolic-and-oleanic-acids-isolates-from-plumeria-obtusa-improves-antioxidant-and-cytotoxic-activity-in-melanoma-cells
#11
Helen L Alvarado, Ana C Calpena, Maria L Garduno-Ramirez, Raul Ortiz, Consolacion Melguizo, Jose M Prados, Beatriz Clares
BACKGROUND: Triterpenoids are an important class of natural bioactive products present in many medicinal plants. OBJECTIVE: The aim of present study is to investigate the antioxidant and anticarcinogenic potential of oleanolic acid (OA) and ursolic acid (UA) on B16 murine melanoma cell line isolated from Plumeria obtusa, free and loaded in a nanoemulsion (NEm) system. METHOD: The nanoemulsion was characterized by dynamic light scattering, transmission electron microscopy...
January 11, 2018: Anti-cancer Agents in Medicinal Chemistry
https://www.readbyqxmd.com/read/29332497/dosimetric-analysis-of-microscopic-disease-in-sbrt-for-lung-cancers
#12
Ronghu Mao, Lingling Tian, You Zhang, Lei Ren, Renqi Gao, Fang-Fang Yin, Hong Ge
OBJECTIVE: The objective of this study is to theoretically and experimentally evaluate the dosimetry in the microscopic disease regions surrounding the tumor under stereotactic body radiation therapy of lung cancer. METHODS: For simplicity, the tumor was considered moving along 1 dimension with a periodic function. The probability distribution function of the tumor position was generated according to the motion pattern and was used to estimate the delivered dose in the microscopic disease region...
December 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/29332230/a-cardioid-oscillator-with-asymmetric-time-ratio-for-establishing-cpg-models
#13
Q Fu, D H Wang, L Xu, G Yuan
Nonlinear oscillators are usually utilized by bionic scientists for establishing central pattern generator models for imitating rhythmic motions by bionic scientists. In the natural word, many rhythmic motions possess asymmetric time ratios, which means that the forward and the backward motions of an oscillating process sustain different times within one period. In order to model rhythmic motions with asymmetric time ratios, nonlinear oscillators with asymmetric forward and backward trajectories within one period should be studied...
January 13, 2018: Biological Cybernetics
https://www.readbyqxmd.com/read/29331892/dynamic-probabilistic-material-flow-analysis-of-nano-sio2-nano-iron-oxides-nano-ceo2-nano-al2o3-and-quantum-dots-in-seven-european-regions
#14
Yan Wang, Bernd Nowack
Static environmental exposure assessment models based on material flow analysis (MFA) have previously been used to estimate flows of engineered nanomaterials (ENMs) to the environment. However, such models do not account for changes in the system behavior over time. Dynamic MFA used in this study includes the time-dependent development of the modelling system by considering accumulation of ENMs in stocks and the environment, and the dynamic release of ENMs from nano-products. In addition, this study also included regional variations in population, waste management systems, and environmental compartments, which subsequently influence the environmental release and concentrations of ENMs...
January 11, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/29331827/pilot-scale-outdoor-photobioreactor-culture-of-the-marine-dinoflagellate-karlodinium-veneficum-production-of-a-karlotoxins-rich-extract
#15
L López-Rosales, A Sánchez-Mirón, F García-Camacho, A R Place, Yusuf Chisti, E Molina-Grima
A pilot-scale bioprocess was developed for the production of karlotoxin-enriched extracts of the marine algal dinoflagellate Karlodinium veneficum. A bubble column and a flat-panel photobioreactors (80-281 L) were used for comparative assessment of growth. Flow hydrodynamics and energy dissipation rates (EDR) in the bioreactors were characterized through robust computational fluid dynamic simulations. All cultures were conducted monoseptically outdoors. Bubble column (maximum cell productivity in semicontinuous operation of 58 × 103 cell mL-1 day-1) proved to be a better culture system for this alga...
December 30, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/29331784/degradation-of-dyes-by-peroxymonosulfate-activated-by-ternary-cofeni-layered-double-hydroxide-catalytic-performance-mechanism-and-kinetic-modeling
#16
Hanxuan Zeng, Weiqiu Zhang, Lin Deng, Jinming Luo, Shiqing Zhou, Xia Liu, Yong Pei, Zhou Shi, John Crittenden
Ternary CoFeNi-layered double hydroxide (CoFeNi-LDH) was synthesized and initially applied to activate peroxymonosulfate (PMS) for the degradation of Congo red (CR) and Rhodamine B (RhB). The results show that the CoFeNi-LDH/PMS system can efficiently degrade nearly 100% of 20 mg/L CR or 20 mg/L RhB within 6- and 10-min reaction times, respectively. And the catalyst exhibits higher degradation efficiency on CR than on RhB under identical conditions, which is confirmed by electron clouds of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) performed by DFT calculations...
January 4, 2018: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29331767/lessons-from-simple-marine-models-on-the-bacterial-regulation-of-eukaryotic-development
#17
REVIEW
Arielle Woznica, Nicole King
Molecular cues from environmental bacteria influence important developmental decisions in diverse marine eukaryotes. Yet, relatively little is understood about the mechanisms underlying these interactions, in part because marine ecosystems are dynamic and complex. With the help of simple model systems, including the choanoflagellate Salpingoeca rosetta, we have begun to uncover the bacterial cues that shape eukaryotic development in the ocean. Here, we review how diverse bacterial cues-from lipids to macromolecules-regulate development in marine eukaryotes...
January 10, 2018: Current Opinion in Microbiology
https://www.readbyqxmd.com/read/29331268/the-population-biology-and-transmission-dynamics-of-loa-loa
#18
REVIEW
Charles Whittaker, Martin Walker, Sébastien D S Pion, Cédric B Chesnais, Michel Boussinesq, María-Gloria Basáñez
Endemic to Central Africa, loiasis - or African eye worm (caused by the filarial nematode Loa loa) - affects more than 10 million people. Despite causing ocular and systemic symptoms, it has typically been considered a benign condition, only of public health relevance because it impedes mass drug administration-based interventions against onchocerciasis and lymphatic filariasis in co-endemic areas. Recent research has challenged this conception, demonstrating excess mortality associated with high levels of infection, implying that loiasis warrants attention as an intrinsic public health problem...
January 10, 2018: Trends in Parasitology
https://www.readbyqxmd.com/read/29331233/a-biophysical-modelling-platform-of-the-cochlear-nucleus-and-other-auditory-circuits-from-channels-to-networks
#19
Paul B Manis, Luke Campagnola
Models of the auditory brainstem have been an invaluable tool for testing hypotheses about auditory information processing and for highlighting the most important gaps in the experimental literature. Due to the complexity of the auditory brainstem, and indeed most brain circuits, the dynamic behavior of the system may be difficult to predict without a detailed, biologically realistic computational model. Despite the sensitivity of models to their exact construction and parameters, most prior models of the cochlear nucleus have incorporated only a small subset of the known biological properties...
December 28, 2017: Hearing Research
https://www.readbyqxmd.com/read/29331143/effects-of-system-size-and-cooling-rate-on-the-structure-and-properties-of-sodium-borosilicate-glasses-from-molecular-dynamics-simulations
#20
Lu Deng, Jincheng Du
Borosilicate glasses form an important glass forming system in both glass science and technologies. The structure and property changes of borosilicate glasses as a function of thermal history in terms of cooling rate during glass formation and simulation system sizes used in classical molecular dynamics (MD) simulation were investigated with recently developed composition dependent partial charge potentials. Short and medium range structural features such as boron coordination, Si and B Qn distributions, and ring size distributions were analyzed to elucidate the effects of cooling rate and simulation system size on these structure features and selected glass properties such as glass transition temperature, vibration density of states, and mechanical properties...
January 14, 2018: Journal of Chemical Physics
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