全文获取类型
收费全文 | 346篇 |
免费 | 10篇 |
出版年
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2017年 | 2篇 |
2016年 | 10篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 24篇 |
2012年 | 24篇 |
2011年 | 25篇 |
2010年 | 19篇 |
2009年 | 15篇 |
2008年 | 26篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 18篇 |
2004年 | 22篇 |
2003年 | 21篇 |
2002年 | 24篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有356条查询结果,搜索用时 31 毫秒
341.
342.
Boczek T Kozaczuk A Taha J Ferenc B Zylinska L 《Indian journal of biochemistry & biophysics》2010,47(5):265-271
Microsomal glutathione transferase 1 (MGST1) is an integral homo-trimeric membrane protein with transferase and peroxidase activities. With glutathione as a co-substrate, it scavenges toxic compounds and may exert anti-apoptotic effect. We examined the effect of suppression of plasma membrane Ca(2+)-ATPase isoforms--PMCA2 or PMCA3 on MGST1 in PC12 cells. GSH level was significantly higher in PMCA2-reduced line, but similar GSSG/GSH ratios in all cell lines suggested an efficient protection or absence of oxidative stress. The ATP concentration decreased in both modified lines, although in PMCA2-suppressed cells the decrease was higher. Total GSTs activity in postmitochondrial fraction increased by 30% in the cells with reduced PMCA3. After treatment with MGST1 activator N-ethylmaleimide (NEM), the activity increased in both transfected lines by 30-40%. Real-time PCR also showed a higher mRNA expression of MGST1 in these lines. Staining with antibody recognizing all cytosolic and membrane-bound GSTs revealed the difference in oligomeric forms of GSTs, and specific anti-MGST1 antibody showed the presence of MGST1 hexamers in the transfected cells. Formation of similar hexamers was detected in the control line after treatment with peroxynitrite. Modification of MGST1 under reduced PMCAs amount may represent an adaptive mechanism that offers protection against the cytotoxicity mediated by increased Ca2+. 相似文献
343.
344.
Tom Bjrnheden Bozena Jakubowicz Max Levin Birgitta Odn Staffan Edn Lars Sjstrm Malin Lnn 《Obesity (Silver Spring, Md.)》2004,12(1):95-105
Objective: Fat cell size is a fundamental parameter in the study of adipose tissue metabolism, because it markedly influences the cellular rates of metabolism. Previous techniques for the sizing of adipocytes are often complicated or time‐consuming. The aim of this study was to develop a new, computerized method for rapid and accurate determination of adipocyte size in a cell suspension obtained by incubating human or rat adipose tissue biopsies with collagenase. Research Methods and Procedures: The cell suspension was placed between a siliconized glass slide and a cover slip. Using the reference method [designated as (R)], the cell diameters were determined manually using a microscope with a calibrated ocular. The new method presented here [designated as (C)] was based on computerized image analysis. Results: After two well‐defined corrective adjustments, measurements with (R) and (C) agreed very well. The small remaining differences seemed, in fact, to depend on inconsistencies in (R). Discussion: We propose that (C) constitutes a valuable tool to study fat cell size, because this method is fast and allows the assessment of a sufficient number of cells to get reliable data on size distribution. Furthermore, images of cell preparations may be stored for future reference. 相似文献
345.
Paulina Paluchowska Marianna Tokarczyk Bozena Bogusz Iwona Skiba Alicja Budak 《Memórias do Instituto Oswaldo Cruz》2014,109(4):436-441
Over the last decades, Candida spp have been responsible for an
increasing number of infections, especially in patients requiring intensive care.
Knowledge of local epidemiology and analysis of the spread of these pathogens is
important in understanding and controlling their transmission. The aim of this study
was to evaluate the genetic diversity of 31 Candida albicans and
17 Candida glabrata isolates recovered from intensive care unit
patients from the tertiary hospital in Krakow between 2011-2012. The strains were
typed by random amplified polymorphic DNA (RAPD) polymerase chain reaction using five
primers (CD16AS, HP1247, ERIC-2, OPE-3 and OPE-18). The results of the present
investigation revealed a high degree of genetic diversity among the isolates. No
clonal relationship was found among the C. albicans strains, whereas
two C. glabrata isolates were identical. The source of
Candida infection appeared to be mostly endogenous; however, the presence
of two clonal C. glabrata strains suggested the possibility of
cross-transmission of these pathogens. Our study confirmed the high discriminatory
power of the RAPD technique in the molecular typing of Candida
clinical isolates. This method may be applied to the evaluation of transmission
routes of pathogenic fungi on a local level. 相似文献
346.
347.
The activity of gamma-glutamyl hydrolase, the enzyme which deglutamylates folyl and antifolyl polyglutamates, changed significantly in mouse cells during different phases of growth, being about two times lower in actively proliferating mice splenocytes and fibroblasts than in nondividing cells. In EAC cells growing in vivo the lowest activity was observed in cells in the logarythmic phase. Methotrexate treatment of mice in a dose of 500 mg/kg body weight increased the activity of the enzyme in EAC cells about 1.5 times. We suggest that gamma-glutamyl hydrolase is a proliferating dependent enzyme which together with folypolyglutamate synthetase ensures in cells an appropriate amount of folates in the form of polyglutamates necessary for optimizing folate-dependent biosynthetic activities. 相似文献
348.
349.
Irving H. Fox Jan Kaminska N. Lawrence Edwards Erwin Gelfand Kenneth C. Rich William N. Arnold 《Biochemical genetics》1980,18(3-4):221-234
Purine and pyrimidine metabolism was compared in erythrocytes from three patients from two families with purine nucleoside phosphorylase deficiency and T-cell immunodeficiency, one heterozygote subject for this enzyme deficiency, one patient with a complete deficiency of hypoxanthine-guanine phosphoribosyltransferase, and two normal subjects. The erythrocytes from the heterozygote subject were indistinguishable from the normal erythrocytes. The purine nucleoside phosphorylase deficient erythrocytes had a block in the conversion of inosine to hypoxanthine. The erythrocytes with 0.07% of normal purine nucleoside phosphorylase activity resembled erythrocytes with hypoxanthine-guanine phosphoribosyltransferase deficiency by having an elevated intracellular concentration of PP-ribose-P, increased synthesis of PP-ribose-P, and an elevated rate of carbon dioxide release from orotic acid during its conversion to UMP. Two hypotheses to account for the associated immunodeficiency—that the enzyme deficiency leads to a block of PP-ribose-P synthesis or inhibition of pyrimidine synthesis—could not be supported by observations in erythrocytes from both enzyme-deficient families.This work was supported by U.S. Public Health Service Grant AM 19674 and 5 M01 RR 42 and by a Grant-In-Aid from American Heart Association (77-849) and with funds contributed in part by the Michigan Heart Association. N.L.E. is a Rheumatology Fellow from the Rackman Arthritis Research Unit supported by Training Grant USPHS AM 07080. 相似文献
350.