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排序方式: 共有341条查询结果,搜索用时 31 毫秒
71.
Xin Wang Adrian M. Dubuc Vijay Ramaswamy Stephen Mack Deena M. A. Gendoo Marc Remke Xiaochong Wu Livia Garzia Betty Luu Florence Cavalli John Peacock Borja López Patryk Skowron David Zagzag David Lyden Caitlin Hoffman Yoon-Jae Cho Charles Eberhart Tobey MacDonald Xiao-Nan Li Timothy Van Meter Paul A. Northcott Benjamin Haibe-Kains Cynthia Hawkins James T. Rutka Eric Bouffet Stefan M. Pfister Andrey Korshunov Michael D. Taylor 《Acta neuropathologica》2015,129(3):449-457
72.
Irradiation with UV‐C inhibits TNF‐α‐dependent activation of the NF‐κB pathway in a mechanism potentially mediated by reactive oxygen species 下载免费PDF全文
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74.
Tymon Warski Adrian Radon Przemyslaw Zackiewicz Patryk Wlodarczyk Marcin Polak Anna Wojcik Wojciech Maziarz Aleksandra Kolano-Burian Lukasz Hawelek 《Materials》2021,14(4)
The effect of substitution of Fe by Cu on the crystal structure and magnetic properties of Fe72−xNi8Nb4CuxSi2B14 alloys (x = 0.6, 1.1, 1.6 at.%) in the form of ribbons was investigated. The chemical composition of the materials was established on the basis of the calculated minima of thermodynamic parameters: Gibbs free energy of amorphous phase formation ΔGamorph (minimum at 0.6 at.% of Cu) and Gibbs free energy of mixing ΔGmix (minimum at 1.6 at.% of Cu). The characteristic crystallization temperatures Tx1onset and Tx1 of the alpha-iron phase together with the activation energy Ea for the as-spun samples were determined by differential scanning calorimetry (DSC) with a heating rate of 10–100 °C/min. In order to determine the optimal soft magnetic properties, the wound cores were subjected to a controlled isothermal annealing process in the temperature range of 340–640 °C for 20 min. Coercivity Hc, saturation induction Bs and core power losses at B = 1 T and frequency f = 50 Hz P10/50 were determined for all samples. Moreover, for the samples with the lowest Hc and P10/50, the magnetic losses were determined in a wider frequency range 50 Hz–400 kHz. The real and imaginary parts of the magnetic permeability µ′, µ″ along with the cut-off frequency were determined for the samples annealed at 360, 460, and 560 °C. The best soft magnetic properties (i.e., the lowest value of Hc and P10/50) were observed for samples annealed at 460 °C, with Hc = 4.88–5.69 A/m, Bs = 1.18–1.24 T, P10/50 = 0.072–0.084 W/kg, µ′ = 8350–10,630 and cutoff frequency at 8–9.3 × 104 Hz. The structural study of as-spun and annealed ribbons was carried out using X-ray diffraction (XRD) and a transmission electron microscope (TEM). 相似文献
75.
P. Hoffmann J. Mazurkiewicz G. Holtmann G. Gerken V. E. Eysselein H. Goebell 《Scandinavian journal of gastroenterology》2013,48(4):414-422
Background: Capsaicin-sensitive nerve fibres protect gastrointestinal mucosa in animal models of mucosal injury by modulation of mucosal blood flow and mucus secretion. The aim of our study was to evaluate the effects of capsaicin-sensitive nerve fibres in rat colonic mucosa on epithelial cell proliferation and transforming growth factor-alpha (TGF α ) expression, which is important in mucosal defence, protection and repair. Methods: Male Wistar rats received either a capsaicin enema with or without giving antagonists to calcitonin-gene-related-peptide (CGRP) or substance P (SP) i.v. immediately prior to the capsaicin enemas; a capsaicin enema after sensory desensitization as described previously; or a vehicle enema. In all experiments, animals received 50 mg/kg BrdU i.v. and were killed at 2, 4, 8, 12, 24 and 48 h after the various treatments. Colonic mucosal specimens were evaluated microscopically for mucosal damage, changes in the numbers of inflammatory cells and BrdU-immunoreactive epithelial cell nuclei. In the same specimens, TGF α -mRNA and-protein expression were evaluated by RT-PCR and Western blot analysis using standardized procedures. Results: A significant increase in the number of mucosal inflammatory cells and an increase in BrdU-immunoreactive nuclei were detected following mucosal exposure to capsaicin. A 2-fold increase of TGF α mRNA and a 10-fold increase of TGF α protein expression were obtained 2-12 h after capsaicin enemas. The effects on the invading number of inflammatory cells and on the increase in BrdU immunoreactive epithelial cell nuclei were significantly reduced by both CGRP and SP antagonists and were abolished in rats previously sensory-desensitized. Conclusion: Capsaicin-sensitive nerve fibres modulate epithelial cell proliferation and TGF α expression in colonic mucosa as well as a migration of inflammatory cells into the colonic mucosa. These effects are mediated by the neurotransmitters CGRP and SP. 相似文献
76.
Nelson LD Bender C Mannsperger H Buergy D Kambakamba P Mudduluru G Korf U Hughes D Van Dyke MW Allgayer H 《Molecular cancer》2012,11(1):38
ABSTRACT: BACKGROUND: Tri- and tetra-nucleotide repeats in mammalian genomes can induce formation of alternative non-B DNA structures such as triplexes and guanine (G)-quadruplexes. These structures can induce mutagenesis, chromosomal translocations and genomic instability. We wanted to determine if proteins that bind triplex DNA structures are quantitatively or qualitatively different between colorectal tumor and adjacent normal tissue and if this binding activity correlates with patient clinical characteristics. METHODS: Extracts from 63 human colorectal tumor and adjacent normal tissues were examined by gel shifts (EMSA) for triplex DNA-binding proteins, which were correlated with clinicopathological tumor characteristics using the Mann-Whitney U, Spearman's rho, Kaplan-Meier and Mantel-Cox log-rank tests. Biotinylated triplex DNA and streptavidin agarose affinity binding were used to purify triplex-binding proteins in RKO cells. Western blotting and reverse-phase protein array were used to measure protein expression in tissue extracts. RESULTS: Increased triplex DNA-binding activity in tumor extracts correlated significantly with lymphatic disease, metastasis, and reduced overall survival. We identified three multifunctional splicing factors with biotinylated triplex DNA affinity: U2AF65 in cytoplasmic extracts, and PSF and p54nrb in nuclear extracts. Super-shift EMSA with anti-U2AF65 antibodies produced a shifted band of the major EMSA H3 complex, identifying U2AF65 as the protein present in the major EMSA band. U2AF65 expression correlated significantly with EMSA H3 values in all extracts and was higher in extracts from Stage III/IV vs. Stage I/II colon tumors (p = 0.024). EMSA H3 values and U2AF65 expression also correlated significantly with GSK3 beta, beta-catenin, and NF- B p65 expression, whereas p54nrb and PSF expression correlated with c-Myc, cyclin D1, and CDK4. EMSA values and expression of all three splicing factors correlated with ErbB1, mTOR, PTEN, and Stat5. Western blots confirmed that full-length and truncated beta-catenin expression correlated with U2AF65 expression in tumor extracts. CONCLUSIONS: Increased triplex DNA-binding activity in vitro correlates with lymph node disease, metastasis, and reduced overall survival in colorectal cancer, and increased U2AF65 expression is associated with total and truncated beta-catenin expression in high-stage colorectal tumors. 相似文献
77.
78.
Krzeminski P Misiewicz I Pomorski P Kasprzycka-Guttman T Barańska J Brańska J 《Brain research bulletin》2007,71(6):587-592
We have previously shown that P2Y1, P2Y2 and P2Y12 nucleotide receptors are functionally expressed and active on the cell surface of rat glioma C6 cells. In the present study, we have immunocytochemically shown their sub-cellular colocalization with mitochondria in these cells. The same colocalization of above receptors has been found in rat astrocytes. Additionally, differences in intracellular distribution of examined receptors between both cell lines have been observed. This data indicates that P2Y1, P2Y2 and P2Y12 receptor proteins exist within mitochondria of astrocytes and C6 cells, although their role in these sub-cellular structures remains unclear. 相似文献
79.
80.
Mazurkiewicz P Sakamoto K Poelarends GJ Konings WN 《Mini reviews in medicinal chemistry》2005,5(2):173-181
Gram-positive lactic acid bacteria possess several Multi-Drug Resistance systems (MDRs) that excrete out of the cell a wide variety of mainly cationic lipophilic cytotoxic compounds as well as many clinically relevant antibiotics. These MDRs are either proton/drug antiporters belonging to the major facilitator superfamily of secondary transporters or ATP-dependent primary transporters belonging to the ATP-binding cassette superfamily of transport proteins. Here we summarize the existing data on these MDRs and discuss recent observations that suggest the use of new strategies in the ongoing battle against drug-resistant microbial pathogens. 相似文献