全文获取类型
收费全文 | 628篇 |
免费 | 36篇 |
国内免费 | 1篇 |
出版年
2022年 | 3篇 |
2021年 | 13篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 22篇 |
2014年 | 30篇 |
2013年 | 56篇 |
2012年 | 72篇 |
2011年 | 56篇 |
2010年 | 26篇 |
2009年 | 28篇 |
2008年 | 32篇 |
2007年 | 29篇 |
2006年 | 23篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 8篇 |
2002年 | 19篇 |
2001年 | 10篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 11篇 |
1978年 | 3篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1975年 | 7篇 |
1974年 | 3篇 |
1970年 | 4篇 |
1965年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有665条查询结果,搜索用时 31 毫秒
61.
The TWEAK–Fn14 system is a critical regulator of denervation-induced skeletal muscle atrophy in mice
Ashwani Mittal Shephali Bhatnagar Akhilesh Kumar Estelle Lach-Trifilieff Sandrine Wauters Hong Li Denys Y. Makonchuk David J. Glass Ashok Kumar 《The Journal of cell biology》2010,188(6):833-849
Skeletal muscle atrophy occurs in a variety of clinical settings, including cachexia, disuse, and denervation. Inflammatory cytokines have been shown to be mediators of cancer cachexia; however, the role of cytokines in denervation- and immobilization-induced skeletal muscle loss remains unknown. In this study, we demonstrate that a single cytokine, TNF-like weak inducer of apoptosis (TWEAK), mediates skeletal muscle atrophy that occurs under denervation conditions. Transgenic expression of TWEAK induces atrophy, fibrosis, fiber-type switching, and the degradation of muscle proteins. Importantly, genetic ablation of TWEAK decreases the loss of muscle proteins and spared fiber cross-sectional area, muscle mass, and strength after denervation. Expression of the TWEAK receptor Fn14 (fibroblast growth factor–inducible receptor 14) and not the cytokine is significantly increased in muscle upon denervation, demonstrating an unexpected inside-out signaling pathway; the receptor up-regulation allows for TWEAK activation of nuclear factor κB, causing an increase in the expression of the E3 ubiquitin ligase MuRF1. This study reveals a novel mediator of skeletal muscle atrophy and indicates that the TWEAK–Fn14 system is an important target for preventing skeletal muscle wasting. 相似文献
62.
Cardioprotective effect of lycopene in the experimental model of myocardial ischemia-reperfusion injury 总被引:1,自引:0,他引:1
Shervington A Cruickshanks N Wright H Atkinson-Dell R Lea R Roberts G Shervington L 《Molecular and cellular biochemistry》2006,283(1-2):1-9
The continuous advancements in cancer research have contributed to the overwhelming evidence of the presence of telomerase
in primary and secondary tumours together with hsp90 and c-Myc. This review will discuss the important role of telomerase together with hsp90 and c-Myc within the initiation and progression of gliomas. Also it will review the differential expression of these genes in the different
grades of gliomas and the possibility of new treatments targeting these specific genes. 相似文献
63.
64.
Antibody-functionalized fluid-permeable surfaces for rolling cell capture at high flow rates 总被引:1,自引:0,他引:1
Adhesion-based cell capture on surfaces in microfluidic devices forms the basis of numerous biomedical diagnostics and in vitro assays. However, the performance of these platforms is partly limited by interfacial phenomena that occur at low Reynolds numbers. In contrast, cell homing to porous vasculature is highly effective in vivo during inflammation, stem cell trafficking, and cancer metastasis. Here, we show that a porous, fluid-permeable surface functionalized with cell-specific antibodies promotes efficient and selective cell capture in vitro. This architecture is advantageous due to enhanced transport as streamlines are diverted toward the surface. Moreover, specific cell-surface interactions are promoted due to reduced shear, allowing gentle cell rolling and arrest. Together, these synergistic effects enable highly effective cell capture at flow rates more than an order of magnitude larger than those provided by existing devices with solid surfaces. 相似文献
65.
Prostate cancer (PCa) is the most common cancer among men. It has been suggested that toll like receptors (TLRs) may contribute to PCa pathogenesis by stimulating prostate epithelial cell proliferation in response to infectious stimuli. We performed case control study to analyze the genetic variants of TLR2, 3 and 9 gene polymorphisms with PCa risk in a North Indian population. For this study we genotyped age matched, unrelated 195 PCa patients and 250 healthy controls of similar ethnicity in a case-control study. They were genotyped for TLR2 (-196 to -174 Del), TLR3 (c.1377C/T) [rs3775290] and TLR9 (G2848A) [rs352140] gene polymorphisms using polymerase chain reaction and restriction fragment length polymorphism method. Variant allele Del (D) carriers i.e. (ID + DD) of TLR2 (-196 to -174 Del) SNP, demonstrated 1.57 fold increased risk (p = 0.040; OR = 1.57, 95% CI = 1.02-2.24) as compared to Ins (I) allele, suggesting a dominant effect model involved in the risk of this polymorphism in PCa. However, variants of TLR3 and 9 gene polymorphisms were not associated with PCa risk. Our results suggested the low penetrance variant of TLR2 (-196 to -174 Del) to be at increased PCa risk in North Indian population. Functional studies in ethnically diverse populations may provide a more comprehensive involvement of innate immunity in identifying the disease-associated variants for PCa etiology. 相似文献
66.
We study the effects of confinement between planar walls on the folding thermodynamics of a β-hairpin, using large-scale replica-exchange molecular-dynamics simulations with an all-atom model and explicit solvent. We find that the folding free-energy landscape of this peptide observed in bulk is significantly modified when the peptide is confined between the walls. Most notably, the propensity of the peptide to form a misfolded state observed in the bulk solution becomes negligible under confinement. The absence of the misfolded state under confinement can be explained by an increased tendency of hydrophobic aromatic side chains to stay near the walls, because the misfolded state is characterized by a nonnative arrangement of aromatic side chains. These results from a simple confinement model may provide clues about the role of chaperonin confinement in smoothing folding landscapes by avoiding trapped intermediates. 相似文献
67.
68.
Chromatophores show significant changes during healing of skin wounds in Labeo rohita (Common Name - Rohu). Wound area can be divided into regions I, II and III. After infliction of wound, skin colour becomes significantly dark by 2 h that is gradually restored by 2 d. In regions II and III at 5 min, epidermal melanophores appear with beaded dendrites. In these regions at 2 h and in region I at 6 h, epidermal melanophores appear small, rounded or irregular shaped having dendritic processes with aggregated melanosomes. Subsequently, melanophores appear having elongated dendrites with dispersed or aggregated melanosomes. At 24 h, clusters of pigmented bodies appear in regions I and II. These bodies increase up to 2 d, and then diminish gradually and disappear by 8 d. Changes in dermal melanophores in region II at 5 min indicate the onset of degeneration. Degenerating melanophores increase up to 12 h, then gradually decline, and disappear by 4 d. Simultaneously, stellate melanophore reappear, gradually increase and appear like control by 8 d. Dermal melanophores in region III at different intervals appear stellate. In region I stellate dermal melanophores appear at 4 d. Stellate melanophores in all regions show different distribution of dispersed or aggregated melanosomes. With the appearance of dermal melanophores, highly refractive, crystalline structures, possibly the refractive platelets of the iridophores, are visualized around them. At subsequent intervals, these are frequently observed. This study provides interesting insights in injury induced changes in chromatophores in fish. The findings could be considered useful in perception of intriguing features in the development of pigment research in future. 相似文献
69.
Background
Carcinoma of gallbladder (GBC) is an aggressive malignancy. The higher incidence of gallbladder cancer in women has been partly attributed to hormonal factors. Therefore the present study was designed to explore the role of genetic variants in estrogen (ESR1, ESR2) and progesterone (PGR) receptors in conferring risk of gallbladder cancer.Materials and Methods
The present case-control study recruited total of 860 subjects, including 410 GBC patients, 230 gallstone patients and 220 controls. We examined the associations of 6 selected polymorphisms in three genes: ESR1 (rs2234693, rs9340799, rs1801132), ESR2 (rs1271572, rs1256049) and PGR (rs1042838) with GBC risk. Genotyping for all the polymorphisms was done using PCR-RFLP. Multifactor dimensionality reduction and classification and regression tree approaches were combined with logistic regression to discover high-order gene-gene interactions in hormonal pathway.Results
On comparing the genotype frequency distribution in gallstone and GBC patients with that of healthy subjects, the homozygous variant genotypes of ESR1-397TT (rs2234693) polymorphism showed significant risk for developing gallstone [odds ratio: OR = 2.9] and GBC [OR = 1.8] respectively. Detailed haplotypes analysis suggested that ESR1 T rs2234693G rs9340799C rs1801132 have significant association in conferring risk for both gallstones [OR = 2.2] and GBC [OR = 3.0]. However, the variant-containing genotypes (DI+II) of PGR (rs1042838) showed low risk in both GBC [OR = 0.4] and gallstone patients [OR = 0.4].On performing the MDR analysis, ESR1 IVS1-397C>T, ESR1 IVS1-351A>G, and ESR2-789 A>C yielded the highest testing accuracy of 0.634. These results were further supported by the CART analysis which revealed that individuals with the combined genotypes of ESR1-397 CT or TT, ESR1-351 AG or GG and ESR2 -789 AA had the highest risk for GBC [OR = 3.9].Conclusion
Using multi-analytical approaches, our study showed important role of ESR1 IVS1-397C>T, ESR1 IVS1-351A>G, and ESR2-789 A>C variants in GBC susceptibility and the risk appears to be mediated through gallstone dependent pathway. 相似文献70.