首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   121篇
  免费   3篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2015年   1篇
  2014年   5篇
  2013年   1篇
  2012年   7篇
  2011年   7篇
  2010年   1篇
  2009年   3篇
  2008年   8篇
  2007年   9篇
  2006年   4篇
  2005年   3篇
  2004年   5篇
  2003年   3篇
  2002年   3篇
  2001年   4篇
  2000年   4篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1992年   4篇
  1991年   4篇
  1990年   6篇
  1989年   3篇
  1988年   7篇
  1987年   3篇
  1986年   3篇
  1985年   4篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1979年   1篇
  1978年   3篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
排序方式: 共有124条查询结果,搜索用时 984 毫秒
111.
Patients with severe COPD are known to have comorbidities such as emaciation, cor pulmonale and right heart failure, muscle weakness, hyperlipemia, diabetes mellitus, osteoporosis, muscle atrophy, arterial sclerosis, hypertension, and depression. Therefore, treatment for COPD needs to focus on these comorbidities as well as the lungs. We previously reported a new mouse model of COPD utilizing the human surfactant protein C promoter SP-C to drive the expression of mature mouse IL-18 cDNA; constitutive IL-18 overproduction in the lungs of transgenic (Tg) mice induces severe emphysematous change, dilatation of the right ventricle, and mild pulmonary hypertension with aging. In the present study, we evaluated the progression of comorbidity in our COPD model. In female Tg mice, significant weight loss was observed at 16 weeks and beyond, when compared with control wild-type (WT) mice. This weight loss was suppressed in IL-13-deficient (knockout; KO) Tg mice. Muscle weight and bone mineral density were significantly decreased in aged Tg mice relative to control WT and IL-13 KO Tg mice. The aged Tg mice also showed impaired glucose tolerance. IL-18 and IL-13 may play important roles in the pathogenesis of comorbidity in COPD patients.  相似文献   
112.
A pig heart phosphoprotein phosphatase with a molecular weight of 224,000 was dissociated in the presence of 40 % ethanol into an active component (C) of molecular weight 31,000 and components (R) of higher molecular weight. After removal of the ethanol, C and R reassociated and formed an enzyme of molecular weight 188,000. C alone could not form the enzyme. The newly formed enzyme had substrate specificity and response to Mg acetate similar to those of the original large form of the enzyme and was clearly distinguishable from C. The ability of R to associate with C was supressed by treatment of R with trypsin or heat (60°C, 2 min), but not with RNase or DNase.  相似文献   
113.
Different forms of cytochrome P-450 from untreated male rats were simultaneously purified to homogeneity using the HPLC technique. The absorption maximum, molecular weight, NH2-terminal sequence and catalytic activity of them were determined. The NH2-terminal sequences of six forms of cytochrome P-450 (designated P450 UT-1, UT-2, UT-4, UT-5, UT-7 and UT-8) indicate that these cytochrome P-450 isozymes are of different molecular species. The hydrophobicity values of the NH2-terminal sequences of P450 UT-1 and P450 UT-8 were lower than that of other forms. P450 UT-8 has the highest molecular weight, 54 000, of the six forms of P-450. P450 UT-2 was active in demethylation of benzphetmaine, 450 UT-4 was active in the metabolism of 7-ethoxycoumarin and p-nitroanisole. P450 UT-1 ad P450 UT-2 were active in the 2α- and 16α-hydroxylation of testosterone, whereas P450 UT-4 was active in the 6β-, 7α- and 15α-hydroxylation of the same steroid. We believe that P450 UT-1, P450 UT-7 and P450 UT-8 are as yet unrecognized forms of cytochrome P-450.  相似文献   
114.
Thermolysin was able to catalyze enantioselective peptide synthesis with non-natural amino acids, halophenylalanines. However, the reactivity of thermolysin was considerably influenced by the kind and position of halogen substituents on these analogues. The manner of the recognition of the amino component by the enzyme was different from that of the carboxyl component in the synthesis of peptides with non-natural phenylalanine analogues. The phenomena observed are discussed, based on the kinetic parameters obtained. Correspondence to: A. Tanaka  相似文献   
115.
The differences in the levels of cytochrome P-450s in hepatic and renal microsomes between spontaneously hypertensive rats (SHR) and normotensive control rats (Wistar Kyoto rats, WKY) were investigated by Western blotting with a specific antibody. Differences in the metabolic activity of the microsomes were also studied. In hepatic microsomes, the content of P450 PB-1 (IIIA2) was 140% higher in SHR than in WKY and the content of P450 IF-3 (IIA1) in SHR was one-seventh that in WKY. The differences reflected the increase in testosterone 6 beta-hydroxylation activity and decrease in testosterone 7 alpha-hydroxylation activity in hepatic microsomes of SHR. The level of P450 K-5 (IVA2) in hepatic microsomes of SHR was 4-times that in microsomes of WKY. The levels of other cytochrome P-450s in SHR were not very different from those in WKY. In renal microsomes, the levels of three renal cytochrome P-450s, P450 K-2, K-4, and K-5, were measured. The level of P450 K-5 (fatty acid omega-hydroxylase) in SHR was 50% higher than that in WKY and the difference reflected the increase in lauric acid omega- and (omega-1)-hydroxylation activities of the renal microsomes of SHR. The levels of P450 K-2 and K-4 did not differ in both rats.  相似文献   
116.
The reconstitution of high O2 evolution in CaCl2-treated PS II particles was achieved by the simultaneous addition of the 17-, 23- and 34-kDa proteins and total thylakoid lipids in the presence of 25% glycerol and 15 mM sodium cholate. The activity of the reconstituted membranes recovered to 85% of that of the non-depleted original PS II particles at the optimal condition. By means of this reconstitution method, evidence for the cooperation of the three proteins in the recovery of O2 evolution in the CaCl2-treated PS II particles was found by changing the concentration of NaCI in the assay medium, and the relationship between the amount of manganese retained in the water-splitting complex and the O2 evolving activity was examined by using the partially solubilized PS II particles with n-octyl-β-D-glucoside.  相似文献   
117.
The amount of cytochrome P-450 in microsomes of rat kidney and lungs was 23 and 7%, respectively, of the amount in microsomes of the liver. HPLC profiles of solubilized microsomes showed that there were five or more forms of cytochrome P-450 in microsomes of kidneys and also of lungs of untreated rats. While 3-methylcholanthrene induced a new form of cytochrome P-450 in kidney and lung microsomes, phenobarbital caused no major change in the HPLC profiles of these microsomes.  相似文献   
118.
Glutathione S-transferases and the cytochrome P450 system have been proposed for the vascular biotransformation systems in the metabolic activation of organic nitrates. The present study was designed to elucidate the role of human cytochrome P450 isoforms on nitric oxide formation from organic nitrates using lymphoblast microsomes transfected with human CYP isoforms cDNA. CYP3A4-transfected microsomes had the most effective potential of nitric oxide formation from isosorbide dinitrate. Anti-CYP3A2 antibody (which cross-reacts with CYP3A4) or ketoconazole (an inhibitor of the CYP3A superfamily) inhibited nitric oxide formation from isosorbide dinitrate in rat heart microsomes. Immunohistochemistry of human heart also showed intense bindings of CYP3A4 antibody in the endothelium of the endocardium and coronary vessels. These results suggest that the CYP3A4-NADPH-cytochrome P450 reductase system specifically participates in nitric oxide formation from isosorbide dinitrate.  相似文献   
119.
Intraoperative cytology was performed for 48 patients with polypoid lesions (36 benign and 12 malignant) of the gallbladder. The cytologic samples consisted of pure bile from 48 patients and diluted bile collected by saline irrigation from 29 patients. Pure bile gave 32 correct diagnoses (67%) and 14 diagnoses of inadequate material (29%), which contained few nondegenerated cells and made microscopic diagnosis unreliable. Inadequate material was frequently obtained in cases of cholesterol polyp (45%), tubular or papillary adenomatous carcinoma (50%) and polypoid carcinoma (17%), but not in cases of inflammatory polyp (0%). On the other hand, cytologic study of bile samples obtained by saline irrigation showed no inadequate material and only one false negative, from a case in which the cancerous focus was mostly covered with nonneoplastic epithelium. These results imply that saline irrigation succeeded in collecting many nondegenerated cells newly exfoliated from the wall of lesions and the technique is useful in the intraoperative cytologic study of polypoid gallbladder lesions.  相似文献   
120.
A. Imaoka    M. Ueno    J. Kihara    M. Kadowaki    S. Arase 《Journal of Phytopathology》2008,156(9):522-529
A lesion-mimic mutant of rice (cv. Sekiguchi-asahi) showed enhanced resistance to Magnaporthe grisea infection, thereby inducing Sekiguchi lesion ( sl ) formation and tryptamine accumulation under light. Both Sekiguchi lesion formation and tryptamine accumulation in leaves infected with M. grisea were inhibited by pretreatment with the photosynthetic inhibitor, 3-(3, 4-Dichlorophenyl)-1,1-dimethylurea (DCMU), which suppressed the gene expression of tryptophan decarboxylase ( TDC ), monoamine oxidase activity, H2O2 generation and DNA fragmentation. Catalase activity was inhibited by M. grisea infection under light, but magnitude of the inhibition was reduced in leaves pretreated with DCMU. Furthermore, tryptophan accumulated in M. grisea- infected leaves under light but not in DCMU-pretreated ones. Interestingly, such DCMU inhibition was reduced in the presence of tryptophan. Our studies suggest that chloroplasts function as the inhibitor of anti-oxidant system such as catalase activity and the supplier of a precursor of tryptamine and tryptophan in the sl mutant infected with M. grisea .  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号