全文获取类型
收费全文 | 7148篇 |
免费 | 322篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 108篇 |
儿科学 | 100篇 |
妇产科学 | 88篇 |
基础医学 | 944篇 |
口腔科学 | 202篇 |
临床医学 | 420篇 |
内科学 | 1941篇 |
皮肤病学 | 127篇 |
神经病学 | 488篇 |
特种医学 | 164篇 |
外科学 | 1257篇 |
综合类 | 22篇 |
预防医学 | 217篇 |
眼科学 | 208篇 |
药学 | 506篇 |
中国医学 | 4篇 |
肿瘤学 | 730篇 |
出版年
2023年 | 32篇 |
2022年 | 71篇 |
2021年 | 127篇 |
2020年 | 67篇 |
2019年 | 90篇 |
2018年 | 147篇 |
2017年 | 109篇 |
2016年 | 138篇 |
2015年 | 155篇 |
2014年 | 153篇 |
2013年 | 236篇 |
2012年 | 378篇 |
2011年 | 425篇 |
2010年 | 238篇 |
2009年 | 210篇 |
2008年 | 367篇 |
2007年 | 405篇 |
2006年 | 401篇 |
2005年 | 419篇 |
2004年 | 395篇 |
2003年 | 406篇 |
2002年 | 393篇 |
2001年 | 160篇 |
2000年 | 189篇 |
1999年 | 149篇 |
1998年 | 132篇 |
1997年 | 91篇 |
1996年 | 75篇 |
1995年 | 50篇 |
1994年 | 70篇 |
1993年 | 55篇 |
1992年 | 127篇 |
1991年 | 113篇 |
1990年 | 105篇 |
1989年 | 95篇 |
1988年 | 102篇 |
1987年 | 88篇 |
1986年 | 64篇 |
1985年 | 79篇 |
1984年 | 39篇 |
1983年 | 35篇 |
1982年 | 27篇 |
1979年 | 24篇 |
1978年 | 25篇 |
1975年 | 20篇 |
1974年 | 19篇 |
1971年 | 22篇 |
1970年 | 22篇 |
1969年 | 23篇 |
1967年 | 23篇 |
排序方式: 共有7526条查询结果,搜索用时 31 毫秒
61.
62.
Inhibition of p38MAP kinase suppresses fibrotic reaction of retinal pigment epithelial cells 总被引:3,自引:0,他引:3
63.
The HLA-DR4 subtypes Dw14 and Dw4 are T-cell-defined allospecificities encoded by the DRB1*0404 and DRB1*0401 genes, respectively. Although these allelic subtypes differ in only two amino acids, allorecognition between Dw14 and Dw4-positive individuals is brisk. This provides an opportunity to analyze T-cell receptor (TCR) usage in a very limited and specifically targeted case, namely the Dw4 anti-Dw14 allogeneic T-cell response. The variable (V), diversity (D), and joining (J) region sequences of the TCR beta chain from two different Dw14-specific alloreactive T-cell clones derived from a Dw4 donor were examined. Clone EMO25 recognized the Dw14.1, Dw14.2, and Dw15 subtypes, which share a DRB1 polymorphism at codon 71 on a DR4 background, while clone EMO36 reacted with only the Dw14.1 subtype associated with polymorphisms at codons 71 and 86. TCR beta cDNA from each clone was amplified using an anchored polymerase chain reaction (PCR) and subsequently expanded with V beta- and C beta-specific primers for asymmetric PCR and direct DNA sequencing. Both clones were found to express the same TCR V beta 8.2 gene segment; however, they have several different residues within the V beta-D beta-J beta junctional regions. V beta 8 usage was also enriched in polyclonal cells obtained from mixed lymphocyte cultures performed between the Dw4 and Dw14 responder-stimulator combination from which EMO25 and EMO36 were derived. 相似文献
64.
WSX-1 is required for resistance to Trypanosoma cruzi infection by regulation of proinflammatory cytokine production 总被引:6,自引:0,他引:6
Hamano S Himeno K Miyazaki Y Ishii K Yamanaka A Takeda A Zhang M Hisaeda H Mak TW Yoshimura A Yoshida H 《Immunity》2003,19(5):657-667
WSX-1 is a class I cytokine receptor with homology to the IL-12 receptors and is essential for resistance to Leishmania major infection. In the present study, we demonstrated that WSX-1 was also required for resistance to Trypanosoma cruzi. WSX-1-/- mice exhibited prolonged parasitemia, severe liver injury, and increased mortality over wild-type mice. WSX-1-/- splenocytes produced enhanced levels of Th2 cytokines, which were responsible for the prolonged parasitemia. Massive necroinflammatory lesions were observed in the liver of infected WSX-1-/- mice, and IFN-gamma that was overproduced in WSX-1-/- mice compared with wild-type mice was responsible for the lesions. In addition, vast amounts of various proinflammatory cytokines, including IL-6 and TNF-alpha, were produced by liver mononuclear cells in WSX-1-/- mice. Thus, during T. cruzi infection, WSX-1 suppresses liver injury by regulating production of proinflammatory cytokines, while controlling parasitemia by suppression of Th2 responses, demonstrating its novel role as an inhibitory regulator of cytokine production. 相似文献
65.
Dynamics of electroencephalographic (EEG) slow wave activity (0.5-4.5 Hz) and body temperature, as estimates, respectively, of the process S and process C, regulating sleep and waking alternate occurrence, were measured during monophasic and biphasic sleep patterns that occurred spontaneously in a 35-year-old woman who lived for 105 days in a winter-type photoperiod (10-14 h light-dark). In monophasic nights, rate of EEG synchronization showed a decreasing trend across the first three non-rapid eye movement (NREM) periods. In biphasic nights, rate of EEG synchronization increased during the third NREM period which precedes the nocturnal awakening. Temperature cycle was not different between biphasic and monophasic nights. Those results confirm that EEG dynamics reflects homeostatic sleep regulatory mechanism, and suggest that the period of prolonged wakefulness in the middle of biphasic night is pre-programmed. 相似文献
66.
The hippocampus is important in learning and memory functions but its ability to aid in these functions declines during aging. In this study, we examined hippocampal proteins whose expressions changed in the aging process. A comparison of synaptosome proteins of hippocampus prepared from young-adult (9-week-old) rats with those from aged (30-month-old) rats by two-dimensional fluorescence difference gel electrophoresis revealed 24 spots that were expressed differently among about 1000 spots detected in both young-adult and aged rat samples. Nineteen of these 24 spots were identified by peptide mass fingerprinting. These proteins included chaperone proteins and proteins related to the cytoskeleton, neurotransmission, signal transduction and energy supply. The cytoskeleton-related proteins included actin and T-complex 1, which is thought to play a role in actin folding. Actin was up-regulated but T-complex 1 was down-regulated in aged rat synapses. These results suggest that age-dependent changes of actin filament formation are related to neuronal dysfunction associated with aging. 相似文献
67.
C Hamanishi Y Ueba T Tsuji S Ijiri T Mihara K Yamanaka T Yamamuro 《American journal of medical genetics》1986,24(2):247-254
Three sibs born to normal but consanguinous parents had flexion deformities of the thumb and fingers on one hand and sensory deficit in the other hand. Extensor muscles were absent or vestigial in all of them. Polyneuropathic electrophysiological findings were detected in 4 limbs. This is an apparently autosomal recessive trait previously unreported. 相似文献
68.
69.
Rare glomerular capillary regeneration and subsequent capillary regression with endothelial cell apoptosis in progressive glomerulonephritis. 总被引:7,自引:1,他引:7
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. Shimizu H. Kitamura Y. Masuda M. Ishizaki Y. Sugisaki N. Yamanaka 《The American journal of pathology》1997,151(5):1231-1239
Glomerulonephritis (GN) leading to glomerular sclerosis remains an important cause of renal failure. The glomerulus is a capillary network, but endothelial and vascular reactions during progressive GN are not well understood. We have, therefore, examined the morphological alterations of glomerular capillary network and endothelial cells during the progression of damaged glomeruli to glomerular sclerosis. A progressive model of anti-glomerular basement membrane (GBM) GN was induced in Wistar-Kyoto (WKY) rats with a single injection of anti-rat GBM antibody. Severe necrotizing glomerular injuries were observed between day 5 and week 3 with a reduction in the number of total glomerular endothelial cells and total glomerular capillary lumina per glomerular cross sections. In necrotizing lesions, the glomerular endothelial cells were lost with the destruction of the glomerular capillary network. Moreover, angiogenic capillary repair with proliferation of endothelial cells was rare in severely damaged regions of glomeruli. Subsequently, mesangial hypercellularity and marked mesangial matrix accumulation occurred with absence of the development of a capillary network, and the necrotizing lesions progressed to sclerotic scars until 8 weeks. Although active necrotizing lesions could not be seen in damaged glomeruli between week 4 and week 8, the number of apoptotic endothelial cells gradually increased in the glomerular capillaries (0.10 +/- 0.01 apoptotic endothelial cells/glomerular cross section at week 8 versus 0.00 +/- 0.00 control cells (mean +/- SEM; P < 0.05) with the progression of glomerular sclerosis. Whereas the number of apoptotic endothelial cells increased in the damaged glomeruli, the number of total glomerular endothelial cells decreased (9.3 +/- 3.0 cells/glomerular cross section at week 8 versus 24.8 +/- 3.0 cells in control (mean +/- SD); P < 0.001) with regression of glomerular capillaries (3.6 +/- 2.5 capillary lumina/glomerular cross section at week 8 versus 35.0 +/- 5.0 capillary lumina in control (mean +/- SD); P < 0.001). Finally, glomerular endothelial cells could not be detected in the sclerotic lesions in progressive anti-GBM GN in WKY rats. These data indicate that the destruction of the capillary network of glomeruli and subsequent incomplete angiogenic capillary repair leads to glomerular sclerosis in progressive GN. Endothelial cell apoptosis with glomerular capillary regression may also contribute to the development of glomerular sclerosis. Injury of the glomerular capillary network with endothelial cell damage, including apoptosis and subsequent incomplete capillary repair, plays an important role in the progression of glomerular sclerosis during anti-GBM GN in WKY rats. 相似文献
70.
M Murakoshi R Inada M Tagawa M Makino M Suzuki M Mieda S Honma Y Takezawa H Yamanaka 《Acta pathologica japonica》1992,42(3):151-157
The effect of a synthetic steroidal anti-androgen, TZP-4238, on spontaneous benign prostatic hyperplasia (BPH) in dogs was investigated. Old male beagle dogs (5-9 years old) were divided into three experimental groups. Group 1 consisted of BPH controls. Groups 2 and 3 received TZP-4238 0.1 mg/kg/day and chlormadinone acetate (CMA) 0.3 mg/kg/day p.o., respectively, for 5 months. In group 1, glandular hyperplasia of the prostate was clearly detected. In contrast, TZP-4238 (Group 2) or CMA (Group 3) produced marked atrophy of the glandular epithelium. In addition, a histopathological study showed that TZP-4238 or CMA medication for 5 months exerted no effect on the testes and the pituitary luteinizing hormone (LH) cells. Therefore, it is suggested that TZP-4238 (0.1 mg/kg) or CMA (0.3 mg/kg) causes regression of spontaneous canine BPH without any histopathological effects on the testes and pituitary LH cells. However, slightly decreased serum testosterone levels were found in TZP-4238-treated animals, due apparently to a direct and/or indirect effect on the testes. Thus, it is suggested that a marginal antigonadotrophic effect cannot be excluded. It is concluded that TZP-4238 is a potent anti-androgen for the treatment of spontaneous canine BPH, without any negative influence on the function of the testes and the pituitary LH cells. 相似文献