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https://www.readbyqxmd.com/read/28454483/efficient-carrier-injection-transport-relaxation-and-recombination-associated-with-a-stronger-carrier-localization-and-a-low-polarization-effect-of-nonpolar-m-plane-ingan-gan-light-emitting-diodes
#1
Fann-Wei Yang, Yu-Siang You, Shih-Wei Feng
Based on time-resolved electroluminescence (TREL) measurement, more efficient carrier injection, transport, relaxation, and recombination associated with a stronger carrier localization and a low polarization effect in a nonpolar m-plane InGaN/GaN light emitting diode (m-LED), compared with those in a polar c-LED, are reported. With a higher applied voltage in the c-LED, decreasing response time and rising time improve device performance, but a longer recombination time degrades luminescence efficiency. By using an m-LED with a stronger carrier localization and a low polarization effect, shorter response, rising, and recombination times provide more efficient carrier injection, transport, relaxation, and recombination...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28454335/effect-of-laser-therapy-on-plasma-expression-of-vegf-and-bfgf-in-infants-with-cutaneous-hemangioma
#2
Fagang Wang, Rongjian Xu, Qian Xu, Yongqian Cao, Li Lin, Wei Dang
The present study aimed to investigate the effect of laser therapy on the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in the plasma of infants diagnosed with cutaneous hemangioma, in order to identify biomarkers for assessing the clinical efficacy of laser therapy. In total, 109 infants with superficial abdominal hemangioma received laser treatment, of which 74 were diagnosed in the proliferation phase, 20 in the regression phase and 15 in the involution phase...
March 2017: Oncology Letters
https://www.readbyqxmd.com/read/28454168/laser-waveform-control-of-extreme-ultraviolet-high-harmonics-from-solids
#3
Yong Sing You, Mengxi Wu, Yanchun Yin, Andrew Chew, Xiaoming Ren, Shima Gholam-Mirzaei, Dana A Browne, Michael Chini, Zenghu Chang, Kenneth J Schafer, Mette B Gaarde, Shambhu Ghimire
Solid-state high-harmonic sources offer the possibility of compact, high-repetition-rate attosecond light emitters. However, the time structure of high harmonics must be characterized at the sub-cycle level. We use strong two-cycle laser pulses to directly control the time-dependent nonlinear current in single-crystal MgO, leading to the generation of extreme ultraviolet harmonics. We find that harmonics are delayed with respect to each other, yielding an atto-chirp, the value of which depends on the laser field strength...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454156/continuously-wavelength-tunable-high-harmonic-generation-via-soliton-dynamics
#4
Francesco Tani, Michael H Frosz, John C Travers, Philip St J Russell
We report the generation of high harmonics in a gas jet pumped by pulses self-compressed in a He-filled hollow-core photonic crystal fiber through the soliton effect. The gas jet is placed directly at the fiber output. As the energy increases, the ionization-induced soliton blueshift is transferred to the high harmonics, leading to emission bands that are continuously tunable from 17 to 45 eV.
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454137/dynamic-stark-shift-induced-by-a-single-photon-packet
#5
D Valente, F Brito, T Werlang
The dynamic Stark shift results from the interaction of an atom with the electromagnetic field. We show how a propagating single-photon wave packet can induce a time-dependent dynamical Stark shift on a two-level system (TLS). A non-perturbative fully quantum treatment is employed, where the quantum dynamics of both the field and the TLS are analyzed. We also provide the means to experimentally access such time-dependent frequency by measuring the interference pattern in the electromagnetic field inside a 1D waveguide...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454021/reactive-mineral-removal-relative-to-soil-organic-matter-heterogeneity-and-implications-for-organic-contaminant-sorption
#6
Fangfang Li, Bo Pan, Ni Liang, Zhaofeng Chang, Yuwei Zhou, Lin Wang, Hao Li, Baoshan Xing
Soil organic matter (SOM) is generally treated as a static compartment of soil in pollutant fate studies. However, SOM might be altered or fractionated in soil systems, and the details of SOM property/composition changes when coupled with contaminant behavior are unknown. In this study, a mild acid treatment was adopted to remove reactive minerals and partially remove SOM components. After acid treatment, biomarker signatures showed that lignin-derived phenols were released and black carbon (as suggested by benzene-polycarboxylic acids) and lipids were enriched...
April 25, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28453995/synthesis-and-mechanistic-evaluation-of-novel-n-benzylidene-carbohydrazide-1h-pyrazolo-3-4-b-pyridine-derivatives-as-non-anionic-antiplatelet-agents
#7
André L Lourenço, Raquel R S Salvador, Leonardo A Silva, Max S Saito, Juliana F R Mello, Lúcio M Cabral, Carlos R Rodrigues, Maria A F Vera, Estela M F Muri, Alessandra M T de Souza, Charles S Craik, Luiza R S Dias, Helena C Castro, Plínio C Sathler
Cardiovascular diseases (CVDs) account for over 17 million deaths globally each year, with atherosclerosis as the underlying cause of most CVDs. Herein we describe the synthesis and in vitro mechanistic evaluation of novel N'-benzylidene-carbohydrazide-1H-pyrazolo[3,4-b]pyridines (3-22) designed as non-anionic antiplatelet agents and presenting a 30-fold increase in potency compared to aspirin. The mechanism underlying their antiplatelet activity was elucidated by eliminating potential targets through a series of in vitro assays including light transmission aggregometry, clot retraction, and quantitative ELISA, further identifying the reduction in biosynthesis of thromboxane B2 as their main mechanism of action...
April 14, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28453963/rare-earth-elements-and-their-release-dynamics-under-pre-definite-redox-conditions-in-a-floodplain-soil
#8
Julia Mihajlovic, Hans-Joachim Stärk, Jörg Rinklebe
For the first time, the impact of pre-definite redox conditions on the release dynamics of rare earth elements (REEs) and the determining factors pH, iron (Fe), manganese (Mn), aluminum (Al), dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and sulfate (SO4(2-)) in a floodplain soil was elucidated using an advanced, highly sophisticated automatic biogeochemical microcosm apparatus. The redox potential (EH) ranged between +82 and + 498 mV during the experiment. The systematic increase of EH caused a decreasing pH from 6...
April 15, 2017: Chemosphere
https://www.readbyqxmd.com/read/28453955/acoustic-tweezing-cytometry-enhances-osteogenesis-of-human-mesenchymal-stem-cells-through-cytoskeletal-contractility-and-yap-activation
#9
Xufeng Xue, Xiaowei Hong, Zida Li, Cheri X Deng, Jianping Fu
Human mesenchymal stem cells (hMSCs) have great potential for cell-based therapies for treating degenerative bone diseases. It is known that mechanical cues in the cell microenvironment play an important role in regulating osteogenic (bone) differentiation of hMSCs. However, mechanoregulation of lineage commitment of hMSCs in conventional two-dimensional (2D) monocultures or bioengineered three-dimensional (3D) tissue constructs remains suboptimal due to complex biomaterial design criteria for hMSC culture...
April 22, 2017: Biomaterials
https://www.readbyqxmd.com/read/28453939/all-atom-molecular-dynamics-simulations-of-peptide-amphiphile-assemblies-that-spontaneously-form-twisted-and-helical-ribbon-structures
#10
Cheng-Tsung Lai, Nathaniel L Rosi, George C Schatz
Self-assembly of peptide amphiphiles (PAs) has been an active research area as the assemblies can be programmed into various shaped nanostructures. Although cylindrical micelles are common structures, gold-binding peptide conjugates PEPAu can self-assemble into chiral nanofibers with single or double helices. When gold nanoparticles bind to the helices, the resulting chiral nanoparticle assemblies have a collective plasmonic circular dichroism signal that can serve as nanoscale circular polarizers or chiroptical sensors...
April 28, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28453938/simulated-force-quench-dynamics-shows-gb1-protein-is-not-a-two-state-folder
#11
Ronen Berkovich, Jagannath Mondal, Inga Paster, Bruce J Berne
Single molecule force spectroscopy is a useful technique for investigating mechanically induced protein unfolding and refolding under reduced forces by monitoring the end-to-end distance of the protein, Ree. The data is often interpreted via a "two-state" model based on the assumption that Ree alone is a good reaction coordinate and the thermodynamic behavior is then ascribed to the free energy as a function of this one reaction coordinate. In this paper, we determined the free energy surface (PMF) of GB1 protein from atomistic simulations in explicit solvent under different applied forces as a function of two collective variables (Ree, and the fraction of native contacts ρ)...
April 28, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28453935/synthesis-of-trialkylhydroxylamines-by-stepwise-reduction-of-o-acyl-n-n-disubstituted-hydroxylamines-substituent-effects-on-the-reduction-of-o-1-acyloxyalkyl-hydroxylamines-and-on-the-conformational-dynamics-of-n-alkoxypiperidines
#12
Sandeep Dhanju, Brendan W Blazejewski, David Crich
The influence of the electron-withdrawing azide group on the reduction of O-(1-acyloxy-ω-azido)hydroxylamines by triethylsilane in the presence of boron trifluoride etherate is studied and found to increase with increasing proximity to the reaction site, suggesting that the reaction proceeds by way of aminoxocarbenium ion intermediates. The ability to carry azides through the reaction sequence affords O-(ω-azidoalkyl-N,N-dialkylhydroxylamines thereby making such functionality available for use in click chemistry...
April 28, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28453933/computational-fluid-dynamics-studies-of-a-flow-reactor-free-energies-of-clusters-of-sulfuric-acid-with-nh3-or-dimethyl-amine
#13
David R Hanson, Imanuel Bier, Baradan Panta, Coty N Jen, Peter H McMurry
Computational fluid dynamics simulations (CFD) of a flow reactor provided 3D spatial distributions of its temperature and flow profiles and abundances of sulfuric acid, nitrogeneous base and the acid-base clusters formed from them. Clusters were simulated via their kinetic formation and decomposition involving sulfuric acid and base molecules. Temperature and flow profiles and the base and sulfuric acid distributions are characterized and the latter is compared to mass spectrometer measurements. Concentrations of simulated clusters of sulfuric acid with either NH3 or dimethylamine were compared to experimentally measured particle concentrations...
April 28, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28453888/live-imaging-of-extracellular-signal-regulated-kinase-and-protein-kinase-a-activities-during-thrombus-formation-in-mice-expressing-biosensors-based-on-f%C3%A3-rster-resonance-energy-transfer
#14
Takuya Hiratsuka, Takeshi Sano, Hisashi Kato, Naoki Komatsu, Masamichi Imajo, Yuji Kamioka, Kenta Sumiyama, Fumiaki Banno, Toshiyuki Miyata, Michiyuki Matsuda
BACKGROUND: Dynamic features of thrombus formation have been visualized by conventional video wide field microscopy or confocal microscopy in live mouse. However, due to technical limitations precise spatiotemporal regulation of intracellular signaling molecule activities, which have been extensively studied in vitro, remains elusive in vivo. OBJECTIVES: By two-photon excitation microscopy of transgenic mice expressing Förster resonance energy transfer (FRET) biosensors for extracellular signal-regulated kinase (ERK) and protein kinase A (PKA), we visualized ERK and PKA activities during thrombus formation in laser-injured subcutaneous arterioles RESULTS: When a core of densely packed platelets was developed, ERK activity was increased from the basal region close to the injured arterioles...
April 28, 2017: Journal of Thrombosis and Haemostasis: JTH
https://www.readbyqxmd.com/read/28453883/stomatal-function-density-and-pattern-and-co2-assimilation-in-arabidopsis-thaliana-tmm1-and-sdd1-1-mutants
#15
Martina Vráblová, Daniel Vrábl, Marie Hronková, Jiří Kubásek, Jiří Šantrůček
Stomata modulate the exchange of water and CO2 between plant and atmosphere. Although stomatal density is known to affect CO2 diffusion into the leaf and thus photosynthetic rate, the effect of stomatal density and patterning on CO2 assimilation is not fully understood. We used wild-types Col-0 and C24 and stomatal mutants sdd1-1 and tmm1 of Arabidopsis thaliana, differing in stomatal density and pattern, to study the effects of these variations on both stomatal and mesophyll conductance and CO2 assimilation rate...
April 28, 2017: Plant Biology
https://www.readbyqxmd.com/read/28453855/newly-characterized-interaction-stabilizes-dna-structure-oligoethylene-glycols-stabilize-g-quadruplexes-ch-%C3%AF-interactions
#16
Hisae Tateishi-Karimata, Tatsuya Ohyama, Takahiro Muraoka, Peter Podbevsek, Adam M Wawro, Shigenori Tanaka, Shu-Ichi Nakano, Kazushi Kinbara, Janez Plavec, Naoki Sugimoto
Oligoethylene glycols are used as crowding agents in experiments that aim to understand the effects of intracellular environments on DNAs. Moreover, DNAs with covalently attached oligoethylene glycols are used as cargo carriers for drug delivery systems. To investigate how oligoethylene glycols interact with DNAs, we incorporated deoxythymidine modified with oligoethylene glycols of different lengths, such as tetraethylene glycol (TEG), into DNAs that form antiparallel G-quadruplex or hairpin structures such that the modified residues were incorporated into loop regions...
April 27, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28453854/the-dynamics-of-the-monomeric-restriction-endonuclease-bcni-during-its-interaction-with-dna
#17
Georgij Kostiuk, Jasmina Dikic, Friedrich W Schwarz, Giedrius Sasnauskas, Ralf Seidel, Virginijus Siksnys
Endonucleases that generate DNA double strand breaks often employ two independent subunits such that the active site from each subunit cuts either DNA strand. Restriction enzyme BcnI is a remarkable exception. It binds to the 5΄-CC/SGG-3΄ (where S = C or G, '/' designates the cleavage position) target as a monomer forming an asymmetric complex, where a single catalytic center approaches the scissile phosphodiester bond in one of DNA strands. Bulk kinetic measurements have previously shown that the same BcnI molecule cuts both DNA strands at the target site without dissociation from the DNA...
April 27, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28453794/blood-flow-competition-after-aortic-valve-bypass-an-evaluation-using-computational-fluid-dynamics
#18
Koji Kawahito, Naoyuki Kimura, Kenji Komiya, Masanori Nakamura, Yoshio Misawa
OBJECTIVES: Aortic valve bypass (AVB) (apico-aortic conduit) remains an effective surgical alternative for patients in whom surgical aortic valve replacement or transcatheter aortic valve implantation is not feasible. However, specific complications include thrombus formation, possibly caused by stagnation arising from flow competition between the antegrade and retrograde flow, but this has not been fully investigated. The aim of this study was to analyse flow characteristics after AVB and to elucidate mechanisms of intra-aortic thrombus using computational fluid dynamics (CFD)...
May 1, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28453740/enhanced-coupling-within-gonadotropic-and-adrenocorticotropic-axes-by-moderate-exercise-in-healthy-men
#19
Ferdinand Roelfsema, Rebecca J Yang, Thomas P Olson, Michael J Joyner, Paul Y Takahashi, Johannes D Veldhuis
Context: Exercise elicits incompletely defined adaptations of metabolic and endocrine milieu, including the gonadotropic and the corticotropic axes. Objective: To quantify the impact of acute exercise on coordinate LH and testosterone and ACTH and cortisol secretion in healthy men in relation to age. Participantsand design: Prospectively randomized, within-subject cross-over, study in 23 men, aged 19-77 yr. Subjects underwent rest and 30 min of mixed exercise at 65% of maximal aerobic capacity with 10-min blood sampling between 0700 and 1300 h 2 wks apart...
April 27, 2017: Journal of Clinical Endocrinology and Metabolism
https://www.readbyqxmd.com/read/28453712/use-of-performance-metrics-for-the-measurement-of-universal-coverage-for-maternal-care-in-mexico
#20
Edson Serván-Mori, David Contreras-Loya, Octavio Gomez-Dantés, Gustavo Nigenda, Sandra G Sosa-Rubí, Rafael Lozano
This study provides evidence for those working in the maternal health metrics and health system performance fields, as well as those interested in achieving universal and effective health care coverage. Based on the perspective of continuity of health care and applying quasi-experimental methods to analyse the cross-sectional 2009 National Demographic Dynamics Survey (n = 14 414 women), we estimated the middle-term effects of Mexico's new public health insurance scheme, Seguro Popular de Salud (SPS) (vs women without health insurance) on seven indicators related to maternal health care (according to official guidelines): (a) access to skilled antenatal care (ANC); (b) timely ANC; (c) frequent ANC; (d) adequate content of ANC; (e) institutional delivery; (f) postnatal consultation and (g) access to standardized comprehensive antenatal and postnatal care (or the intersection of the seven process indicators)...
June 1, 2017: Health Policy and Planning
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