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61.
The crystal structure of the NF-kappa B p65 (RelA) homodimer in complex with a DNA target has been determined to 2.4 A resolution. The two p65 subunits are not symmetrically disposed on the DNA target. The homodimer should optimally bind to a pseudo-palindromic nine base pair target with each subunit recognizing a 5'GGAA-3' half site separated by a central A-T base pair. However, one of the subunits (subunit B) encounters a half site of 5'-GAAA-3'. The single base-pair change from G-C to A-T results in highly unfavorable interactions between this half site and the base contacting protein residues in subunit B, which leads to an 18 degrees rotation of the N-terminal terminal domain from its normal conformation. Remarkably, subunit B retains all the interactions with the sugar phosphate backbone of the DNA target. This mode of interaction allows the NF-kappa B p65 homodimer to recognize DNA targets containing only one cognate half site. Differences in the sequence of the other half site provide variations in conformation and affinity of the complex.  相似文献   
62.
To identify proteins associated with esophageal carcinogenesis, we performed protein profiling of 16 esophageal squamous cell carcinomas (ESCCs) and paired noncancerous tissues by 2-DE and MS/MS. In cancerous tissues, three spots showed significant up-regulation in the amount of protein, while eight spots were significantly down-regulated. The identities of the spots were determined by PMF with LC-MS/MS and were confirmed by immunoblotting. The up-regulated proteins were tropomyosin alpha 4 chain, transgelin, and pyruvate kinase. The down-regulated proteins were serum albumin precursor, isoforms of annexin A1, tropomyosin beta chain, 14-3-3 protein sigma, and isoforms of serotransferrin precursor. In all 16 cases, up-regulation of the tropomyosin alpha 4 chain was confirmed by immunoblotting. Localization of the tropomyosin alpha 4 chain in ESCC cells and adjacent fibroblasts was confirmed by immunohistochemistry.  相似文献   
63.
The influences of mechanical force during physical exercise on blood coagulation and fibrinolysis were investigated and the effects of sports equipment, especially shoes were also examined. As an experimental model, local mechanical vibration was applied to the palm of the hand. General coagulation parameters did not change, but fibrinolytic activity was elevated due to the tissue plasminogen activator (t-PA) released from vascular endothelial cells stimulated by vibration. The influence of mechanical stimulation by repeated side-jumping with bare feet was examined on the sole of the foot. As with t-PA, the von Willebrand Factor antigen (vWF:Ag) derived from vascular endothelial cells also tended to increase, but not as much as when wearing sports shoes. Sports shoes protected the blood vessels of the feet from damage by mechanical force during physical exercise. Changes in fibrinolytic activity and t-PA could be useful for assessing local mechanical stimulation during physical exercise and also as indexes for the development of new sports equipment and its improvement.  相似文献   
64.
Isotonic load stress dependence of biomimetic soft actuators based on polypyrrole tubes has been studied to elucidate the work behaviour. Polypyrrole (PPy) tubes were electrochemically prepared on gold coated acryl resin in an aqueous solution of pyrrole and dodecylbenzensulfonic acid (DBS). The tubes were operated electrochemically in aqueous 1 M LiCl, and the change of tube length was measured under various load stresses. It was found that with increasing load stresses the response time slowed down and the contraction ratio reduced. Hence, the current decreased and lasted longer, indicating that the tube was sensing the load stress. During contraction of the tube, the conversion efficiency was estimated from the electrical input and mechanical output energies to be 0.12%. The maximum volumetric work was approximately 120 kJ/m3. The results were discussed taking the dynamics of ion migration into consideration.  相似文献   
65.
Two methods for the fault location in PV module string were experimentally studied. One was the earth capacitance measurement (ECM) and the other was the time-domain reflectometry (TDR). By ECM, the disconnection position in the string was estimated by the earth capacitance value without the effects of the irradiance change, and the estimation error was small enough to determine the disconnection position in actual repair/maintenance operation. On the other hand, TDR could detect the degradation (series resistance increase) and the positions in the string by the change of response waveform.  相似文献   
66.
We studied efficacy and safety of sulbactam/cefoperazone (SBT/CPT) in the treatment of biliary tract infections in hospitalized patients at 26 hospitals from February 1993 to March 1995. Secondary to dropout, 273 out of 338 patients entered in the study were evaluated, 127 patients with cholecystitis, 132 patients with cholangitis, and 14 patients with liver abscesses. Of these, 93 patients (34.1% had malignancy as an underlying disease. SBT/CPZ had an efficacy of 79.9% (218 patients; excellent: 52, good: 166), with the efficacy in patients with cholecystitis, cholangitis and liver abscess at 89.0% (113 patients), 77.3% (102 patients and 21.4% (3 patients), respectively. A significant difference (p < 0.05) was observed in the efficacy rates of patients with (59 patients [63.4%]) and without malignancy (159 patients [88.3%]). A total of 84 strains were isolated from bile specimens of 53 patients, and the major isolates were Escherichia coli, Pseudomonas aeruginosa and Enterococcus spp. Two or more bacterial strains were isolated simultaneously in 20 patients. Mild or moderate side effect (allergic reaction including rash etc.) were noted in 4 patients (1.18%), and laboratory abnormalities (increased GOT, etc.) were in 16 patients (4.71%) out of the total 338 patients. This study clearly demonstrated that SBT/CPZ retains its excellent clinical efficacy and safety profile, throughout its use over the past decade.  相似文献   
67.
Enzootic bovine leukosis (EBL) is a B-cell lymphosarcoma caused by the bovine leukemia virus (BLV). Most BLV-infected cattle show no clinical signs and only some develop EBL. The pathogenesis of EBL remains unclear and there are no methods for predicting EBL before its onset. Previously, it was reported that miRNA profiles in milk small extracellular vesicles (sEVs) were affected in cattle in the late stage of BLV infection. It raised a possibility that miRNA profile in milk sEVs from EBL cattle could be also affected. To characterize the difference in milk of EBL cattle and healthy cattle, we examined the miRNA profiles in milk sEVs from four EBL and BLV-uninfected cattle each using microarray analysis. Among the detected miRNAs, three miRNAs—bta-miR-1246, hsa-miR-1290, and hsa-miR-424-5p—which were detectable using quantitative real-time PCR (qPCR) and are associated with cancers in humans—were selected as biomarker candidates for EBL. To evaluate the utility of these miRNAs as biomarkers for EBL, their levels were measured using milk that was freshly collected from 13 EBL and seven BLV-uninfected cattle. bta-miR-1246 and hsa-miR-424-5p, but not hsa-miR-1290, were detected using qPCR and their levels in milk sEVs from EBL cattle were significantly higher than those in BLV-uninfected cattle. bta-miR-1246 and hsa-miR-424-5p in sEVs may promote metastasis by targeting tumor suppressor genes, resulting in increased amounts in milk sEVs in EBL cattle. These results suggest that bta-miR-1246 and hsa-miR-424-5p levels in milk sEVs could serve as biomarkers for EBL.  相似文献   
68.
基于MOS-1b/MESSR的洪灾遥感监测   总被引:1,自引:0,他引:1       下载免费PDF全文
以湖南洞庭湖为研究区,MOS-1b/MESSR影像数据作为遥感信息源,应用ERDAS IMAGINE处理系统,对枯水期和洪水期两个不同时相的各波段影像数据进行组合运算、比值变换等处理,以及影像、光谱、直方图的对比分析。基于处理与分析结果,利用分类技术,建立了水体分类模型(B1+B2)/(B3+B4)>t,可快速准确地提取水体信息;同时,还提取和建立了水深系数模型WDI=B1/B2,得出了基于非线性回归分析的水体深度探测模型。依据洪水信息提取模型,对枯水期与洪水期的分类专题图进行叠加分析,得到了洞庭湖区洪水期的洪水分布图与洪水淹没信息,可为防洪救灾决策提供重要的科学依据。  相似文献   
69.
70.
To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg. Soc. Japan, 50, 117-125 (2009)]. To confirm the validity of the method, an interlaboratory collaborative study was conducted. In the collaborative study, conversion factors (Cfs), which are required to calculate the GMO amount (%), were first determined for two real-time PCR instruments, the ABI PRISM 7900HT and the ABI PRISM 7500. A blind test was then conducted. The limit of quantitation for both GA21 and P35S was estimated to be 0.5% or less. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)). The determined bias and RSD(R) were each less than 25%. We believe the developed method would be useful for the practical screening analysis of GM maize.  相似文献   
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