1,758 research outputs found
Preparation and Characterization of High-Temperature Thermally Stable Alumina Composite Membrane
A crack- and pinhole-free composite membrane consisting of an α-alumina support and a modified Îł-alumina top layer which is thermally stable up to 1100°C was prepared by the solâgel method. The supported thermally stable top layer was made by dipcoating the support with a boehmite sol doped with lanthanum nitrate. The temperature effects on the microstructure of the (supported and unsupported) La-doped top layers were compared with those of a common Îł-alumina membrane (without doping with lanthanum), using the gas permeability and nitrogen adsorption porosimetry data. After sintering at 1100°C for 30 h, the average pore diameter of the La-doped alumina top layer was 17 nm, compared to 109 nm for the common alumina top layer. Addition of poly(vinyl alcohol) to the colloid boehmite precursor solution prevented formation of defects in the Îł-alumina top layer. After sintering at temperatures higher than 900°C, the common alumina top layer with addition of poly(vinyl alcohol) exhibits a bimodal pore distribution. The La-doped alumina top layer (also with addition of poly(vinyl alcohol)) retains a monopore distribution after sintering at 1200°C
Entanglement filter with Rydberg atoms
Devices capable of deterministically manipulating the photonic entanglement
are of paramount importance, since photons are the ideal messengers for quantum
information. Here, we report a Rydberg-atom-based entanglement filter that
preserves the desired photonic entangled state and deterministically blocks the
transmission of the unwanted ones. Photonic entanglement with near-unity
fidelity can be extracted from an input state with an arbitrarily low initial
fidelity. The protocol is inherently robust, and succeeds both in the Rydberg
blockade regime and in the interaction-induced dissipation regime. Such an
entanglement filter opens new routes toward scalable photonic quantum
information processing with multiple ensembles of Rydberg atoms.Comment: 10 pages for manuscript with 4 figures, 16 pages for Supplementary
information with 7 figures and 2 table
Enhanced surface acceleration of fast electrons by using sub-wavelength grating targets
Surface acceleration of fast electrons in intense laser-plasma interaction is
improved by using sub-wavelength grating targets. The fast electron beam
emitted along the target surface was enhanced by more than three times relative
to that by using planar target. The total number of the fast electrons ejected
from the front side of target was also increased by about one time. The method
to enhance the surface acceleration of fast electron is effective for various
targets with sub-wavelength structured surface, and can be applied widely in
the cone-guided fast ignition, energetic ion acceleration, plasma device, and
other high energy density physics experiments.Comment: 14 pages, 4figure
DiaquaÂbis(5-carbÂoxy-2-methyl-1H-imidazole-4-carboxylÂato-Îș2 N 3,O 4)manganese(II)
The title complex, [Mn(C6H5N2O4)2(H2O)2], was obtained by hydroÂthermal synthesis. The MnII atom, which lies on an inversion centre, displays a slightly distorted octaÂhedral geometry. In the crystal packing, complex molÂecules are linked by interÂmolecular OâHâŻO and NâHâŻO hydrogen bonds to form a three-dimensional supramolecular structure. The title complex is isostructural with the corresponding cadmium(II) complex [Nie, Wen, Wu, Liu & Liu (2007 â¶). Acta Cryst. E63, m753âm755]
ExpressĂŁo nĂŁo equilibrada do receptor de hidrocarboneto arĂlico nos linfĂłcitos T CCR6+ CD4+ e CD4+ CD25+ do sangue perifĂ©rico na artrite reumatoide
ResumoObjetivoAnalisar o papel do receptor de hidrocarboneto arĂlico (AhR) nos linfĂłcitos T CCR6+ CD4+ e CD4+ CD25+ no sangue perifĂ©rico de pacientes com artrite reumatoide (AR).MĂ©todosFoi aplicada citometria de fluxo para determinar a proporção de cĂ©lulas AhR positivas em linfĂłcitos CCR6+ CD4+ e CD4+ CD25+ do sangue perifĂ©rico e cĂ©lulas mononucleares perifĂ©ricas de cada indivĂduo. Os nĂveis de expressĂŁo relativa de ĂĄcido ribonucleico mensageiro (do inglĂȘs ribonucleic acid, RNAm,) de AhR e RNAm de enzima de primeiro estĂĄgio essencial para o AhR (CYP1A1) foram testados por reação em cadeia de polimerase (do inglĂȘs polymerase chain reaction, PCR,) em tempo real.ResultadosA percentagem de cĂ©lulas AhR positivas nas cĂ©lulas mononucleares do sangue perifĂ©rico foi maior no grupo com AR do que nos indivĂduos saudĂĄveis [(35,23±10,71)% vs. (18,83±7,32)%, (p<0,01)]. Os nĂveis de expressĂŁo de AhR e CYP1A1 estavam aumentados em pacientes com AR quando comparados com os controles [(3,71±1,63) vs. (2,00±1,27), p=0,002; (2,62±2,08) vs. (0,62±0,29), p<0,01, respectivamente]. Em pacientes com AR, a percentagem de cĂ©lulas AhR positivas nos linfĂłcitos T CD4+ CD25+ foi significativamente inferior Ă dos controles [17,90 (6,10±80,10)]% vs. (52,49±19,18)%, p < 0,01]; em controles saudĂĄveis, a percentagem de cĂ©lulas AhR positivas nos linfĂłcitos T CD4+ CD25+ foi significativamente mais elevada do que nos linfĂłcitos T CCR6+ CD4+ e tambĂ©m foi significativamente maior do que nas cĂ©lulas mononucleares do sangue perifĂ©rico (do inglĂȘs peripheral blood mononuclear cells, PBMC,) [(52,49±19,18)% vs. (23,18±5,62)% vs. (18,06±7,80)%, X 2=24,03, p < 0,01]; em pacientes com AR, a percentagem de cĂ©lulas AHR positivas nos linfĂłcitos T CCR6+ CD4+ era significativamente maior em comparação com os linfĂłcitos T CD4+ CD25+ e PBMC (46,02±14,68)% vs. [17,90 (6,10±80.10)]% vs. (34,22±10,33)%, X 2=38,29, p<0,01]; no entanto, nĂŁo foi encontrada correlação estatisticamente significativa entre os dados clĂnicos e cĂ©lulas AhR positivas em linfĂłcitos T CCR6+ CD4+ e CD4+ CD25+.ConclusĂŁoO Ahr pode participar do progresso patolĂłgico da AR ao controlar a diferenciação de linfĂłcitos Th17 e Treg no sangue perifĂ©rico.AbstractObjectiveThe goal of this study was to analyze the role of aryl hydrocarbon receptor in peripheral blood CCR6+ CD4+ and CD4+ CD25+T cells of patients with rheumatoid arthritis.MethodsFlow cytometry was applied to determine the proportion of AhR positive cells in CCR6+ CD4+T, CD4+ CD25+T and peripheral blood peripheral mononuclear cells from each subject. AhR mRNA and CYP1A1 mRNA relative expression levels were tested by realâtime PCR.ResultsThe percentage of AhR positive cells in peripheral blood mononuclear cells was higher in RA group than that in healthy cases [(35.23±10.71) % vs. (18.83±7.32) %, (p<0.01)]. The expression levels of AhR and CYP1A1 were both increased in patients with RA while compared to controls [(3.71±1.63) vs. (2.00±1.27), p=0.002; (2.62±2.08) vs. (0.62±0.29), p<0.01, respectively]. In RA patients, the percentage of AhR positive cells in CD4+CD25+T cells was significantly lower than that from controls [17.90(6.10±80.10)]% vs. (52.49±19.18)%, p<0.01]; In healthy controls, the percentage of AhR positive cells in CD4+CD25+T cells was significantly higher than that in CCR6+CD4+T cells, and was also significantly higher than that in PBMCs [(52.49±19.18)% vs. (23.18±5.62)% vs. (18.06±7.80)%, X2=24.03, p<0.01]; in RA patients, the percentage of AhR positive cells in CCR6+CD4+T cells was significantly increased than that in CD4+CD25+T cells and PBMCs (46.02±14.68)% vs. [17.90 (6.10±80.10)] %vs. (34.22±10.33)%, X2=38.29, p<0.01]; Nevertheless, no statistically significant relationship was found between clinical data and AhR positive cells in CCR6+CD4+T and CD4+ CD25+T cells.ConclusionAhR may participate in the pathological progress of RA by controlling the differentiation of Th17 and Treg cells in peripheral blood
Comparative Proteomic Analysis Reveals Proteins Putatively Involved in Toxin Biosynthesis in the Marine Dinoflagellate Alexandrium catenella
Alexandrium is a neurotoxin-producing dinoflagellate genus resulting in paralytic shellfish poisonings around the world. However, little is known about the toxin biosynthesis mechanism in Alexandrium. This study compared protein profiles of A. catenella collected at different toxin biosynthesis stages (non-toxin synthesis, initial toxin synthesis and toxin synthesizing) coupled with the cell cycle, and identified differentially expressed proteins using 2-DE and MALDI-TOF-TOF mass spectrometry. The results showed that toxin biosynthesis of A. catenella occurred within a defined time frame in the G1 phase of the cell cycle. Proteomic analysis indicated that 102 protein spots altered significantly in abundance (P < 0.05), and 53 proteins were identified using database searching. These proteins were involved in a variety of biological processes, i.e., protein modification and biosynthesis, metabolism, cell division, oxidative stress, transport, signal transduction, and translation. Among them, nine proteins with known functions in paralytic shellfish toxin-producing cyanobacteria, i.e., methionine S-adenosyltransferase, chloroplast ferredoxin-NADP+ reductase, S-adenosylhomocysteinase, adenosylhomocysteinase, ornithine carbamoyltransferase, inorganic pyrophosphatase, sulfotransferase (similar to), alcohol dehydrogenase and arginine deiminase, varied significantly at different toxin biosynthesis stages and formed an interaction network, indicating that they might be involved in toxin biosynthesis in A. catenella. This study is the first step in the dissection of the behavior of the A. catenella proteome during different toxin biosynthesis stages and provides new insights into toxin biosynthesis in dinoflagellates
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Monitoring of the central blood pressure waveform via a conformal ultrasonic device.
Continuous monitoring of the central-blood-pressure waveform from deeply embedded vessels, such as the carotid artery and jugular vein, has clinical value for the prediction of all-cause cardiovascular mortality. However, existing non-invasive approaches, including photoplethysmography and tonometry, only enable access to the superficial peripheral vasculature. Although current ultrasonic technologies allow non-invasive deep-tissue observation, unstable coupling with the tissue surface resulting from the bulkiness and rigidity of conventional ultrasound probes introduces usability constraints. Here, we describe the design and operation of an ultrasonic device that is conformal to the skin and capable of capturing blood-pressure waveforms at deeply embedded arterial and venous sites. The wearable device is ultrathin (240 ÎŒm) and stretchable (with strains up to 60%), and enables the non-invasive, continuous and accurate monitoring of cardiovascular events from multiple body locations, which should facilitate its use in a variety of clinical environments
Outreach syphilis testing services by different health providers to female sex workers in southern China.
Health providers have played important roles on delivering prevention and care services to control syphilis in China. The current study was aimed to evaluate the performance of different health providers in providing outreach syphilis testing services to female sex workers (FSWs). The current study carried out during April to August 2009 in Liuzhou was aimed to investigate the services delivered by two different types of clinics in China. A total of 1,808 FSWs recruited from sex work venues were included in the study. Prevalence of positive syphilis test (6.4%) among FSWs accessed by the local center for disease control outreach teams (CDC teams) was significantly lower than that (9.3%) among FSWs accessed by the local reproductive health hospital outreach teams (RHH teams). As compared with CDC teams, RHH teams had more FSWs to be successfully referred to the designated STD clinics for further syphilis confirmation and intervention (85.7% vs. 26.7%, P<0.001). These findings indicate that RHH teams may be more efficient than CDC teams to provide outreach-based services to FSWs. Participation of the reproductive health providers or other medical facilities in outreach services to FSWs should be considered in developing intervention programs in China
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