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排序方式: 共有321条查询结果,搜索用时 15 毫秒
81.
Ville Saarimaa Nuria Fuertes Dan Persson Tommy Zavalis Aaretti Kaleva Juha-Pekka Nikkanen Erkki Levänen Golrokh Heydari 《工业材料与腐蚀》2020,71(10):1619-1628
In this study, the local electrochemical activity of untreated and passivated (natural or chemical passivation) zinc specimens was observed during immersion in a 0.1-M NaCl solution. The localized anodic activity during the exposure, measured with the scanning vibrating electrode technique, was linked to zinc dissolution by the pitting corrosion mechanism. It was correlated to specific corrosion products characterized by Fourier transmission infrared (FTIR) microscopy. FTIR molecule maps were produced from individual pitting corrosion sites (100–200 µm in width). With argon ion beam milling and latest energy-dispersive X-ray spectroscopy (EDS) technology, element maps with a high spatial resolution (≪100 nm) were recorded from abrasion- and beam-sensitive corrosion products, showing a residual layer structure. This study demonstrates the capability of FTIR mapping, cross-section polishing, and state-of-the-art scanning electron microscopy imaging, and EDS element mapping to produce high-resolution elemental, molecular, and visual information about pitting corrosion mechanisms on a hot-dip galvanized steel sample. 相似文献
82.
María N. Barrachina Irene Izquierdo Lidia Hermida-Nogueira Luis A. Morn Amparo Prez Ana B. Arroyo Nuria García-Barber Rocío Gonzlez-Conejero Sara Troitio Johannes A. Eble Jos Rivera Constantino Martínez María I. Loza Eduardo Domínguez ngel García 《International journal of molecular sciences》2021,22(7)
Background: Clinical management of ischemic events and prevention of vascular disease is based on antiplatelet drugs. Given the relevance of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) as a candidate target in thrombosis, the main goal of the present study was to identify novel antiplatelet agents within the existing inhibitors blocking PI3K isoforms. Methods: We performed a biological evaluation of the pharmacological activity of PI3K inhibitors in platelets. The effect of the inhibitors was evaluated in intracellular calcium release and platelet functional assays, the latter including aggregation, adhesion, and viability assays. The in vivo drug antithrombotic potential was assessed in mice undergoing chemically induced arterial occlusion, and the associated hemorrhagic risk evaluated by measuring the tail bleeding time. Results: We show that PI3K Class IA inhibitors potently block calcium mobilization in human platelets. The PI3K p110δ inhibitor Idelalisib inhibits platelet aggregation mediated by ITAM receptors GPVI and CLEC-2, preferentially by the former. Moreover, Idelalisib also inhibits platelet adhesion and aggregation under shear and adhesion to collagen. Interestingly, an antithrombotic effect was observed in mice treated with Idelalisib, with mild bleeding effects at high doses of the drug. Conclusion: Idelalisib may have antiplatelet effects with minor bleeding effects, which provides a rationale to evaluate its antithrombotic efficacy in humans. 相似文献
83.
Ledentsov N Bimberg D Hopfer F Mutig A Shchukin V Savel'ev A Fiol G Stock E Eisele H Dähne M Gerthsen D Fischer U Litvinov D Rosenauer A Mikhrin S Kovsh A Zakharov N Werner P 《Nanoscale research letters》2007,2(9):417-429
We report on progress in growth and applications of submonolayer (SML) quantum dots (QDs) in high-speed vertical-cavity surface-emitting
lasers (VCSELs). SML deposition enables controlled formation of high density QD arrays with good size and shape uniformity.
Further increase in excitonic absorption and gain is possible with vertical stacking of SML QDs using ultrathin spacer layers.
Vertically correlated, tilted or anticorrelated arrangements of the SML islands are realized and allow QD strain and wavefunction
engineering. Respectively, both TE and TM polarizations of the luminescence can be achieved in the edge-emission using the
same constituting materials. SML QDs provide ultrahigh modal gain, reduced temperature depletion and gain saturation effects
when used in active media in laser diodes. Temperature robustness up to 100 °C for 0.98 μm range vertical-cavity surface-emitting
lasers (VCSELs) is realized in the continuous wave regime. An open eye 20 Gb/s operation with bit error rates better than
10−12 has been achieved in a temperature range 25–85 °C without current adjustment. Relaxation oscillations up to ∼30 GHz have been realized indicating feasibility of 40 Gb/s signal transmission.
A. V. Savel’ev—on leave from the Abraham Ioffe Physical Technical Institute, Politekhnicheskaya 26, 194021, St. Petersburg,
Russia. 相似文献
84.
Paula Gonzlez-Lpez Carla Ares-Carral Andrea R. Lpez-Pastor Jorge Infante-Menndez Tamara Gonzlez Illaness Melina Vega de Ceniga Leticia Esparza Nuria Beneit Jos Luis Martín-Ventura
scar Escribano Almudena Gmez-Hernndez 《International journal of molecular sciences》2022,23(18)
(1) Background: Cardiovascular diseases (CVDs) are the main cause of death in developed countries, being atherosclerosis, a recurring process underlying their apparition. MicroRNAs (miRNAs) modulate the expression of their targets and have emerged as key players in CVDs; (2) Methods: 18 miRNAs were selected (Pubmed and GEO database) for their possible role in promoting atherosclerosis and were analysed by RT-qPCR in the aorta from apolipoprotein E-deficient (ApoE−/−) mice. Afterwards, the altered miRNAs in the aorta from 18 weeks-ApoE−/− mice were studied in human aortic and carotid samples; (3) Results: miR-155-5p was overexpressed and miR-143-3p was downregulated in mouse and human atherosclerotic lesions. In addition, a significant decrease in protein kinase B (AKT), target of miR-155-5p, and an increase in insulin-like growth factor type II receptor (IGF-IIR), target of miR-143-3p, were noted in aortic roots from ApoE−/− mice and in carotid plaques from patients with advanced carotid atherosclerosis (ACA). Finally, the overexpression of miR-155-5p reduced AKT levels and its phosphorylation in vascular smooth muscle cells, while miR-143-3p overexpression decreased IGF-IIR reducing apoptosis in vascular cells; (4) Conclusions: Our results suggest that miR-155-5p and miR-143-3p may be implicated in insulin resistance and plaque instability by the modulation of their targets AKT and IGF-IIR, contributing to the progression of atherosclerosis. 相似文献
85.
Nuria Crdenas-Quesada Leticia Díaz-Beltrn Carmen Rosa-Garrido Blgica Mrquez-Lobo Adela Sabio-Gonzlez Rafael J. Luque-Barona María Isabel Núez Pedro Snchez-Rovira 《International journal of molecular sciences》2022,23(22)
Nowadays, the impact of the tumor-immune microenvironment (TME) in non-small-cell lung cancer (NSCLC) prognosis and treatment response remains unclear. Thus, we evaluated the expression of PD-L1, tumor-infiltrating lymphocytes (TILs), and transforming growth factor beta (TGF-β) in NSCLC to identify differences in TME, detect possible new prognostic factors, and assess their relationship. We retrospectively analyzed 55 samples from patients who underwent NSCLC surgery and had over a 5-year follow-up. PD-L1 expression was determined by immunohistochemistry following standard techniques. The presence of TILs was evaluated at low magnification and classified into two categories, “intense” and “non-intense”. Cytoplasmic TGF-β staining visualization was divided into four categories, and unequivocal nuclear staining in >1% of viable tumor cells was defined as “present” or “absent”. Our aim was to identify differences in disease-free survival (DFS) and overall survival (OS). Tumor stage was the only objective prognostic factor for OS. PD-L1 expression and the presence of TILs had no prognostic impact, neither their combination. There seems to be a lower expression of PD-L1 and a higher expression of TILs in early stages of the disease. Our TGF-β nuclear staining analysis was promising, since it was associated with worse DFS, revealing this protein as a possible prognostic biomarker of recurrence for resectable NSCLC. 相似文献
86.
87.
88.
A method to detect obstacle-free paths in real-time which works as part of a cognitive navigation aid system for visually impaired people is proposed. It is based on the analysis of disparity maps obtained from a stereo vision system which is carried by the blind user. The presented detection method consists of a fuzzy logic system that assigns a certainty to be part of a free path to each group of pixels, depending on the parameters of a planar-model fitting. We also present experimental results on different real outdoor scenarios showing that our method is the most reliable in the sense that it minimizes the false positives rate. 相似文献
89.
Domínguez A Torner N Ruiz L Martínez A Bartolomé R Sulleiro E Teixidó A Plasencia A 《Journal of food protection》2007,70(1):209-213
In most developed countries, nontyphoid Salmonella is an important cause of sporadic cases and outbreaks of foodborne gastroenteritis. The aim of this study was to investigate the trend of foodborne Salmonella-caused outbreaks and number of cases, hospitalizations, and deaths and compare them with those caused by other infectious agents. The study was carried out in Catalonia, a region in northeastern Spain with a population of 6.5 million inhabitants, in 2002. All information on reported outbreaks of foodborne disease from 1990 to 2003 was reviewed. For each outbreak, the following variables were collected: year; setting (household, restaurant, school, hospital, nursing home, and others); number of cases, hospitalizations, and deaths; causal agent; and food vehicle involved. Of 1652 reported outbreaks, 1078 had a known causal agent. Among them, 871 (80.8%) were caused by Salmonella, with 14,695 cases, 1534 hospitalizations, and 4 deaths. The rate of hospitalization was higher in outbreaks due to Salmonella than in those caused by other infectious agents (rate ratio, 2.54; 95% confidence interval, 2.20 to 2.94). Forty-eight percent of Salmonella-caused outbreaks were eggborne, compared with 5.3% of those caused by other infectious agents (rate ratio, 1.40; 95% confidence interval, 1.33 to 1.48). The annual number of cases in household outbreaks of eggborne Salmonella rose over time (R2 = 0.82), but the number of outbreaks produced in other settings did not. Eggborne outbreaks caused by Salmonella in households are a major cause of disease, and increased preventive efforts are necessary, especially consumer education and awareness of the risk of eating food containing raw or slightly cooked eggs. 相似文献
90.