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排序方式: 共有649条查询结果,搜索用时 31 毫秒
31.
Diabetes and the role of isoprenoid biosynthesis 总被引:2,自引:0,他引:2
Bliznakov EG 《FEBS letters》2002,525(1-3):169-170
32.
Jolanda?HM?van Bilsen Josée?PA?Wagenaar-Hilbers Maarten?JF?van der Cammen Mariska?EA?van Dijk Willem?van Eden Marca?HM?WaubenEmail author 《Arthritis research & therapy》2002,4(4):R2
We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental
arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the
course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration
of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the
MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP
peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development
of such therapies. 相似文献
33.
Andriambeloson E Witting PK 《Redox report : communications in free radical research》2002,7(3):131-136
The detailed chemistry of nitric oxide (*NO) and regulation of this potent signal molecule through interactions with cellular components are complex and not clearly understood. In the vasculature, *NO plays a crucial role in vessel dilation by activating soluble guanylyl cyclase (sGC) in vascular smooth muscle cells (VSMC). *NO is responsible for maintaining coronary blood flow and normal cardiac function. However, *NO is a highly reactive molecule and this reactivity toward a range of alternate substrates may interfere with the activation of its preferred molecular target within VSMC. Interestingly, marked changes to *NO homeostasis are linked to disease progression. Thus, the physiological concentration of *NO is carefully regulated. Myoglobin is a haem-containing protein that is present in relatively high concentration in cardiac and skeletal muscle. Recently, the presence of myoglobin has been confirmed in human smooth muscle. The role of intracellular myoglobin is generally accepted as that of a passive di-oxygen storage protein. However, oxygenated myoglobin readily reacts with *NO to yield higher order N-oxides such as nitrate, while both the ferrous and ferric forms of the protein form a stable complex with *NO. Together, these two reactions effectively eliminate *NO on the physiological time-scale and strongly support the idea that myoglobin plays a role in maintaining *NO homeostasis in tissues that contain the protein. Interestingly, human myoglobin contains a sulfhydryl group and forms an S-nitroso-adduct similar to haemoglobin. In this article we discuss the potential for human myoglobin to actively participate in the regulation of *NO by three distinct mechanisms, namely oxidation, ligand binding, and through formation of biologically active S-nitroso-myoglobin. 相似文献
34.
35.
Marcil V Delvin E Seidman E Poitras L Zoltowska M Garofalo C Levy E 《American journal of physiology. Gastrointestinal and liver physiology》2002,283(2):G340-G346
Short-chain fatty acids (SCFAs) are potent modulators of the growth, function, and differentiation of intestinal epithelia. In addition, high-fiber diets may protect against the development of atherosclerosis because of their cholesterol-lowering effects due, in large part, to SCFA production, liver sterol metabolism, and bile acid excretion. Although the small gut plays a major role in dietary fat transport and contributes substantially to plasma cholesterol and lipoprotein homeostasis, the impact of SCFAs on intestinal lipid handling remains unknown. In the present study, the modulation of lipid synthesis, apolipoprotein biogenesis, and lipoprotein secretion by butyrate was investigated in Caco-2 cells plated on permeable polycarbonate filters, which permit separate access to the upper and lower compartments of the monolayers. Highly differentiated and polarized cells (20 days of culture) were incubated for 20 h with 20 mM butyrate in the apical medium. In the presence of [14C]oleic acid, butyrate led to a significant reduction of secreted, labeled triglycerides (27%; P < 0.01) and phospholipids (25%; P < 0.05). Similarly, butyrate significantly decreased the incorporation of [14C]acetate into exported cholesteryl ester (49%; P < 0.005). As expected from these results, with [14C]oleic acid as a precursor, butyrate significantly (P < 0.05) diminished the delivery of radiolabeled chylomicrons and very low-density lipoproteins. In parallel, [35S]methionine pulse labeling of Caco-2 cells revealed the concomitant inhibitory effect of butyrate on the synthesis of apolipoproteins B-48 (28%; P < 0.05) and A-I (32%; P < 0.01). Collectively, our data indicate that butyrate may influence lipid metabolism in Caco-2 cells, thus suggesting a potential regulation of intestinal fat absorption and circulating lipoprotein concentrations. 相似文献
36.
37.
Mame?Oureye SyEmail author Maurice?Sagna Sire?Diedhiou Claudine?Franche Florence?Auguy Emile?Duhoux 《In vitro cellular & developmental biology. Plant》2003,39(5):545-550
Summary The purpose of this study was to establish an efficient in vitro nodulation device for producing actinorhizal root nodules on Allocasuarina verticillata and Casuarina glauca. Seeds from the two species were germinated aseptically and seedlings with at least two photosynthetic branchlets and a 3–5
cm long root system were transferred into Petri dishes containing a biphasic (solid/liquid) medium. To assess the nodulation
capacity, four different culture media were tested. As soon as the root system developed and spread adequately on the surface
of the medium, plants were deprived of nitrogen for at least 1 wk and inoculated with the Frankia strain. The time course nodulation for A. verticillata showed that the basal Hoagland medium supplemented with CaCO3 and KNO3 was most efficient, with 83% of plantlets forming nodules, while the medium supplemented with CaCO3 reached 100% nodulation for C. glauca. This procedure can provide a valuable tool for the study of early events of actinorhizal nodulation and spatio-temporal
expression of symbiotic genes in transgenic Casuarinaceae. 相似文献
38.
Koop EA Lopes SM Feiken E Bluyssen HA van der Valk M Voest EE Mummery CL Moolenaar WH Gebbink MF 《The International journal of developmental biology》2003,47(5):345-354
The receptor-like protein tyrosine phosphatase mu (RPTPmu) belongs to the subfamily of meprin, A5, RPTPmu (MAM) domain-containing RPTPs, which are thought to play an important role in cell-cell adhesion mediated processes. The current study was designed to examine the expression pattern of RPTPmu in mice. We have generated RPTPmu-LacZ knock-in mice that express the beta-galactosidase (LacZ) reporter gene under the control of the RPTPmu promoter. LacZ expression patterns were analysed in embryos and adult mice by whole mount LacZ staining. Analysis of beta-galactosidase activity of heterozygous embryos and adult tissues revealed RPTPmu expression in endothelial cells of arteries and capillaries. In contrast, expression was virtually absent in endothelial cells of veins and in fenestrated endothelial cells in the adult liver and spleen. Moreover, RPTPmu expression was found in endothelial cells from the endocardium and the aorta in embryos, but not in adult mice. In addition to heterogeneous expression in endothelial cells, RPTPmu expression was found in cardiac muscle cells but not in skeletal muscle cells or smooth muscle cells. Expression was also found in Type II pneumonocytes in the lung alveoli and in Purkinje cells and other neurons in the brain. The specific expression of RPTPmu in arterial endothelial cells and in cardiac myocytes suggests that RPTPmu may play a role in the regulation of cardiovascular functions. 相似文献
39.
Control of seed dormancy in Nicotiana plumbaginifolia: post-imbibition abscisic acid synthesis imposes dormancy maintenance 总被引:13,自引:0,他引:13
The physiological characteristics of seed dormancy in Nicotiana plumbaginifolia Viv. are described. The level of seed dormancy is defined by the delay in seed germination (i.e the time required prior to
germination) under favourable environmental conditions. A wild-type line shows a clear primary dormancy, which is suppressed
by afterripening, whereas an abscisic acid (ABA)-deficient mutant shows a non-dormant phenotype. We have investigated the
role of ABA and gibberellic acid (GA3) in the control of dormancy maintenance or breakage during imbibition in suitable conditions. It was found that fluridone,
a carotenoid biosynthesis inhibitor, is almost as efficient as GA3 in breaking dormancy. Dry dormant seeds contained more ABA than dry afterripened seeds and, during early imbibition, there
was an accumulation of ABA in dormant seeds, but not in afterripened seeds. In addition, fluridone and exogenous GA3 inhibited the accumulation of ABA in imbibed dormant seeds. This reveals an important role for ABA synthesis in dormancy
maintenance in imbibed seeds.
Received: 31 December 1998 / Accepted: 9 July 1999 相似文献
40.
Detailed imaging and genetic analysis reveal a secondary BRAFL505H resistance mutation and extensive intrapatient heterogeneity in metastatic BRAF mutant melanoma patients treated with vemurafenib 下载免费PDF全文
Inge Ubink Nicolle J. M. Besselink Mark Pieterse Wouter Veldhuis Marijn van Stralen Eelco F. J. Meijer Stefan M. Willems Michael A. Hadders Thomas Kuilman Oscar Krijgsman Daniel S. Peeper Marco J. Koudijs Edwin Cuppen Emile E. Voest Martijn P. Lolkema 《Pigment cell & melanoma research》2015,28(3):318-323
Resistance to treatment is the main problem of targeted treatment for cancer. We followed ten patients during treatment with vemurafenib, by three‐dimensional imaging. In all patients, only a subset of lesions progressed. Next‐generation DNA sequencing was performed on sequential biopsies in four patients to uncover mechanisms of resistance. In two patients, we identified mutations that explained resistance to vemurafenib; one of these patients had a secondary BRAF L505H mutation. This is the first observation of a secondary BRAF mutation in a vemurafenib‐resistant patient‐derived melanoma sample, which confirms the potential importance of the BRAF L505H mutation in the development of therapy resistance. Moreover, this study hints toward an important role for tumor heterogeneity in determining the outcome of targeted treatments. 相似文献