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排序方式: 共有1294条查询结果,搜索用时 31 毫秒
21.
Estelle Glais Vesna orevi Jelena Papan Bruno Viana Miroslav D. Dramianin 《RSC advances》2018,8(33):18341
MgTiO3 nanoparticles doped with Mn4+, with homogeneous size ranging about 63.1 ± 9.8 nm, were synthesized by a molten salt assisted sol gel method. These nanoparticles have been investigated as optical thermal sensors. The luminescence of tetravalent manganese ion in octahedral environment within the perovskite host presents drastic variations with temperature. Three different thermometry approaches have been proposed and characterized. Two luminescence intensity ratios are studied. Firstly between the two R-lines of Mn4+ emission at low temperature (−250 °C and −90 °C) with a maximal sensitivity of 0.9% °C−1, but also secondly between 2E → 4A2 (R-line) and the 4T2 → 4A2 transitions. This allows studying the temperature variation within a larger temperature range (−200 °C to 50 °C) with a sensitivity between 0.6% °C−1 and 1.2% °C−1 over this range. The last proposed method is the study of the lifetime variation versus temperature. The effective lifetime value corresponds to a combination of transitions from two excited energy levels of the tetravalent manganese (2E and 4T2) in thermal equilibrium toward the fundamental 4A2 state. Since the more energetic transition (4T2 → 4A2) is spin-allowed, contrary to the 2E → 4A2 one, the lifetime drastically decreases with the increase in temperature leading to an impressive high sensitivity value of 4.1% °C−1 at 4 °C and an exceptional temperature resolution of 0.025 °C. According to their optical features, MgTiO3:Mn4+ nanoparticles are indeed suitable candidates for the luminescence temperature probes at the nanoscale over several temperature ranges.Luminescence properties of MgTiO3 nanoparticles doped with Mn4+ ions are investigated for precise temperature determination. 相似文献
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Graldine Dantelle Denis Testemale Estelle Homeyer Alexandra Cantarano Stphanie Kodjikian Christophe Dujardin Jean-Louis Hazemann Alain Ibanez 《RSC advances》2018,8(47):26857
Ce3+-doped Y3Al5O12 (YAG:Ce) nanocrystals were synthesized by a unique solvothermal method, under sub-critical conditions. A home-made autoclave was used, operating in a larger pressure and temperature range than that with conventional commercial equipment and allowing direct in situ photoluminescence (PL) and X-ray absorption characterizations. The study of various synthesis conditions (pressure, temperature, precursor concentration, reaction time) allowed the best reaction conditions to be pinpointed to control YAG:Ce nanocrystal size, as well as crystal quality, and to get efficient optical properties. Without any post thermal treatment, we succeeded in obtaining well-crystallized YAG:Ce nanocrystals (30–200 nm), displaying typical PL properties of YAG:Ce with a maximal emission at 550 nm. The pristine 100 nm-sized YAG:Ce nanoparticles present an internal quantum yield of about 40 ± 5%. In situ X-ray absorption near edge spectroscopy demonstrates the presence of Ce4+ in nanocrystals elaborated at high temperature, resulting from the oxidation of Ce3+ during the crystallization process.This modified solvothermal method, combined with in situ photoluminescence measurements, allows the synthesis of well-crystallized size-controlled YAG:Ce nanocrystals. 相似文献
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Crutel Véronique Lambert Estelle Penelaud Pierre-François Albarrán Severo Cristina Fuentes Joaquin Rosier Antoine Hervás Amaia Marret Stéphane Oliveira Guiomar Parellada Mara Kyaga Simon Gouttefangeas Sylvie Bertrand Marianne Ravel Denis Falissard Bruno 《Journal of autism and developmental disorders》2021,51(8):2973-2973
Journal of Autism and Developmental Disorders - The author of the article would like to add a video abstract as a supplementary material for a published article. The supplementary file is published... 相似文献
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Fc receptor gamma-chain activation via hOSCAR induces survival and maturation of dendritic cells and modulates Toll-like receptor responses 下载免费PDF全文
Merck E de Saint-Vis B Scuiller M Gaillard C Caux C Trinchieri G Bates EE 《Blood》2005,105(9):3623-3632
We previously reported the characterization of human osteoclast-associated receptor (hOSCAR), a novel Fc receptor gamma-chain (FcRgamma)-associated receptor expressed by myeloid cells. Here we show that ligation of hOSCAR by specific antibodies promotes dendritic cell (DC) survival by an extracellular signal-regulated kinase (ERK)- and phosphatidylinositol 3-kinase (PI3K)-dependent pathway, linked to expression of the Bcl-2 and Bcl-x(L) antiapoptotic molecules. Crosslinking of hOSCAR leads to maturation of DCs, as demonstrated by up-regulation of maturation markers, decrease in dextran uptake capacity, and secretion of immunesystem effectors such as interleukin-8 (IL-8)/CXC chemokine ligand 8 (CXCL8), IL-12 p40, monocyte chemoattractant protein-1 (MCP-1)/chemokine receptor ligand 2 (CCL2) and macrophage-derived chemokine (MDC)/CCL22. Stimulation of hOSCAR acts in conjunction with the Toll-like receptor (TLR) ligands, lipopolysaccharide (LPS), R-848, and polyinosinic-polycytidylic acid (poly(I:C)), to increase the expression of maturation markers, and to modulate cytokine release. A PI3K-dependent up-regulation of IL-10 release is observed with all the TLR ligands used, whereas regulation of IL-12 production is variable depending on the TLR stimulated. hOSCAR engagement on DCs did not significantly increase the proliferation of naive T cells; however, when co-incubated with TLR ligands, an enhanced proliferation was observed. The percentage of interferon (IFN)-gamma-producing T cells is decreased when hOSCAR engagement is combined with LPS stimulation. Altogether, these data suggest that hOSCAR may modulate the responses of both innate resistance and adaptive immunity. 相似文献
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Comparison of human skeletal myoblasts and bone marrow-derived CD133+ progenitors for the repair of infarcted myocardium 总被引:5,自引:0,他引:5
Agbulut O Vandervelde S Al Attar N Larghero J Ghostine S Léobon B Robidel E Borsani P Le Lorc'h M Bissery A Chomienne C Bruneval P Marolleau JP Vilquin JT Hagège A Samuel JL Menasché P 《Journal of the American College of Cardiology》2004,44(2):458-463
OBJECTIVES: The present study was designed as a face-to-face functional comparison of human skeletal myoblasts (SMs) and CD133(+) bone marrow-derived hematopoietic progenitors in an animal model of semichronic myocardial infarction. BACKGROUND: Compared with SMs, bone marrow-derived cells have the advantage of plasticity and might more effectively regenerate ischemic cardiac tissue. However, few data exist on the comparative efficacy of these two cell types in semichronic infarcts. METHODS: A myocardial infarction was created by coronary ligation in 32 nude rats. Ten days later, rats received in-scar injections of human SMs, CD133(+) progenitors, or culture medium. Left ventricular function was assessed before and one month after transplantation by echocardiography and pressure-volume loops. Immunofluorescence, polymerase chain reaction, and in situ hybridization were used to detect cells grafted in the hearts. RESULTS: One month after transplantation, left ventricular ejection fraction decreased by 8 +/- 4% in controls, whereas it increased by 7 +/- 3% in CD133(+)-grafted hearts (p = 0.0015 vs. controls) and further by 15 +/- 5% in SM-treated hearts (p = 0.008 vs. controls). Systolic indices yielded by pressure-volume loops paralleled these data. Engrafted myotubes were identified in all SM-treated hearts by immunofluorescence, whereas in CD133(+)-grafted hearts, few human cells were only detected by polymerase chain reaction. CONCLUSIONS: In the setting of postinfarction scars, the transplantation of bone marrow-derived CD133(+) progenitors improves cardiac function, but this benefit is not superior to that afforded by myogenic cells. 相似文献
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King LA Nogareda F Weill FX Mariani-Kurkdjian P Loukiadis E Gault G Jourdan-DaSilva N Bingen E Macé M Thevenot D Ong N Castor C No?l H Van Cauteren D Charron M Vaillant V Aldabe B Goulet V Delmas G Couturier E Le Strat Y Combe C Delmas Y Terrier F Vendrely B Rolland P de Valk H 《Clinical infectious diseases》2012,54(11):1588-1594
29.
Among patient with alcohol use disorders (AUD), cognitions (beliefs, thoughts, schemas) play an important role in alcohol abuse and in craving, defined as a strong and irresistible urge to consume a product. Various types of beliefs, said to be dysfunctional, were specifically identified among AUD patient as being able to favor a relapse. The aim of this research concerns the comorbidity (qualitative part of the research) and the dysfunctional beliefs relative to the craving (quantitative part of the research). The evolution of craving related beliefs are analyzed during a post-cure care. Ten French patients in post-cure care for AUD were received in clinical interview, and in structured interview (MINI). They also filled the French form of the Craving Beliefs Questionnaire at the two moments: At the beginning of post-cure care, then at the end. On the quantitative part, the results show that the irrational beliefs decrease among every patient. However, this evolution is not correlated with the number of post-cure care from which they benefit. A hypothesis is whether it is the global residential care in itself that influences the cognitions-beliefs. 相似文献
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