全文获取类型
收费全文 | 127122篇 |
免费 | 10858篇 |
国内免费 | 7981篇 |
专业分类
耳鼻咽喉 | 1387篇 |
儿科学 | 1741篇 |
妇产科学 | 989篇 |
基础医学 | 12261篇 |
口腔科学 | 2220篇 |
临床医学 | 14212篇 |
内科学 | 18560篇 |
皮肤病学 | 1454篇 |
神经病学 | 6291篇 |
特种医学 | 5191篇 |
外国民族医学 | 41篇 |
外科学 | 14627篇 |
综合类 | 24265篇 |
现状与发展 | 32篇 |
一般理论 | 15篇 |
预防医学 | 10420篇 |
眼科学 | 2390篇 |
药学 | 12891篇 |
116篇 | |
中国医学 | 7136篇 |
肿瘤学 | 9722篇 |
出版年
2024年 | 357篇 |
2023年 | 1419篇 |
2022年 | 3715篇 |
2021年 | 5222篇 |
2020年 | 3960篇 |
2019年 | 3304篇 |
2018年 | 3518篇 |
2017年 | 3674篇 |
2016年 | 3627篇 |
2015年 | 5513篇 |
2014年 | 7000篇 |
2013年 | 7096篇 |
2012年 | 10613篇 |
2011年 | 11531篇 |
2010年 | 8827篇 |
2009年 | 7424篇 |
2008年 | 8586篇 |
2007年 | 8665篇 |
2006年 | 7824篇 |
2005年 | 7129篇 |
2004年 | 5270篇 |
2003年 | 4950篇 |
2002年 | 4256篇 |
2001年 | 2731篇 |
2000年 | 2153篇 |
1999年 | 1534篇 |
1998年 | 1017篇 |
1997年 | 1032篇 |
1996年 | 696篇 |
1995年 | 655篇 |
1994年 | 534篇 |
1993年 | 354篇 |
1992年 | 325篇 |
1991年 | 269篇 |
1990年 | 203篇 |
1989年 | 168篇 |
1988年 | 159篇 |
1987年 | 124篇 |
1986年 | 118篇 |
1985年 | 70篇 |
1984年 | 64篇 |
1983年 | 34篇 |
1982年 | 33篇 |
1981年 | 26篇 |
1980年 | 27篇 |
1979年 | 19篇 |
1978年 | 19篇 |
1975年 | 16篇 |
1973年 | 16篇 |
1972年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
目的 :探讨夜间电子生物阻抗测量装置 (NEVA)在阴茎勃起功能障碍的诊断中的应用价值。方法 :对 4 1例主诉阴茎勃起功能障碍者 (障碍组 ) 19例主诉无勃起功能障碍但有射精障碍者 (无障碍组 )进行NEVA检测。结果 :障碍组夜间试验中的夜间勃起的次数、阴茎勃起的最大体积改变、最长持续时间等客观指标均要差于无障碍组 ,差异有统计学意义 (P <0 .0 1)。结论 :NEVA为非侵入性检测、可鉴别心理性阴茎勃起功能障碍和严重的器质性勃起功能障碍 ,且对勃起功能障碍的定性和定量具有一定的客观性。 相似文献
52.
ΔNp63蛋白在膀胱移行上皮癌中的表达及其临床意义 总被引:3,自引:1,他引:2
目的 :探讨 p5 3基因家族新成员截短型p6 3(△Np6 3)在膀胱癌组织中的表达及其意义。 方法 :采用免疫组织化学SP法检测 4 0例膀胱移行上皮癌 (TCC)、6例膀胱内翻性乳头状瘤和 8例正常膀胱移行上皮中△Np6 3的表达 ,并分析△Np6 3表达与膀胱癌病理类型、临床分期的关系。 结果 :正常膀胱移行上皮、膀胱内翻性乳头状瘤、TCC中△Np6 3的阳性表达率分别为 37.5 % (3/ 8)、6 6 .7% (4/ 6 )、10 0 % (40 / 4 0 ) ,组间差异有统计学意义 (P <0 .0 1)。TCCG3 级与G2 级△Np6 3的强阳性、中度阳性表达率显著高于G1级 (P <0 .0 1)。Ta~T1期以△Np6 3弱阳性为主 (6 6 .7% ) ,随TCC浸润程度的增加 ,△Np6 3染色强度逐渐增强。T2 期△Np6 3强阳性表达率为 35 .3% ,T3 ~T4期增至 6 3.6 %。结论 :△Np6 3在TCC中高表达 ,与TCC病理分级、临床分期密切相关 ;△Np6 3可能参与TCC的发生、发展 ,是评估TCC预后的潜在因素之一。 相似文献
53.
甲基强的松龙治疗实验性变态反应性脑脊髓炎的作用机制 总被引:1,自引:0,他引:1
目的:研究细胞因子、T细胞凋亡和淋巴细胞增殖在实验性变态反应性脑脊髓炎(EAE)形成中的作用及甲基强的松龙(MP)治疗EAE的作用机制。方法:采用人脑纯化的髓鞘碱性蛋白(MBP)与完全福氏佐剂免疫Lewis大鼠,建立EAE动物模型。用双抗体夹心ELISA法检测各组大鼠血清中IL-10、TNF-α、IFN-γ的含量:流式细胞仪检测外周血T细胞凋亡;3H-TdR释放法检测外周血淋巴细胞转化率。结果:与对照组比较,EAE组的外周血IFN-γ、TNF-α水平明显增高,IL-10水平明显降低,MP治疗后IFN-γ和TNF-α水平下降,IL-10浓度上调。MP还诱导外周血T细胞凋亡和抑制MBP致敏淋巴细胞增殖并呈剂量依赖性。结论:应用人MBP成功建立EAE大鼠模型,MP可能通过调节Th细胞因子格局、促进Th2细胞因子分泌、抑制MBP致敏淋巴细胞增殖及外周血T细胞凋亡而发挥治疗多发性硬化的作用。 相似文献
54.
55.
Susumu Akimoto Koichiro Akakura Takemasa Ohki Jun Shimazaki 《International journal of urology》1994,1(3):263-267
To compare levels of y-seminoprotein (gM-Sm) assayed by original and revised assay systems, blood was obtained every 4 h over a 32-h period from 8 untreated prostate cancer patients. Serum levels of prostate specific antigen (PSA) were also examined. In 6 patients, the coefficient of variation (CV) of the serum levels assayed by the revised assay was significantly different from that of the intra-assay samples. In contrast, the CV of the gM-Sm serum levels assayed by the original assay differed significantly from that of the intra-assay samples in only 2 patients. The fluctuations in gM-Sm assayed by the revised assay were, at least in part, similar to those of the PSA serum levels in all patients. The mean CV of the gM-Sm serum levels assayed by the revised assay was significantly larger than that for levels measured by the original assay. After treatment, the rate of decrease in gM-Sm serum levels determined by the original assay differed from that in the serum levels of PSA and prostatic acid phosphatase. These results indicate that the original assay for gM-Sm do not detect diurnal differences in serum gM-Sm levels, even at levels below 20 ng/ml. These observations indicate that the analysis of data obtained using the original gM-Sm kit should be interpreted with caution. 相似文献
56.
57.
Mapping of the 5' ends of virion-derived hepatitis B virus DNA molecules was carried out after cloning and sequencing linearized genomes made fully double stranded. Of five clones obtained, three of four minus strand termini mapped to the G in position 1826 and one to the T in position 1827. Plus strand 5' ends were more heterogeneous with evidence from one clone for the presence of an RNA-translocated primer from the 5' end of pregenomic RNA as well as two other termini, mapped to positions 1599 and 1601, the second 3' nucleotide of DR2 and the first nucleotide 3' to DR2, respectively. These molecules were also shown to be functional templates for expression of HBcAg after tranfection or microinjection of Huh-7 human hepatoma cells. 相似文献
58.
59.
Fluid-fluid levels in cavernous hemangioma of soft tissue 总被引:3,自引:0,他引:3
Shigeru Ehara M.D. Miyuki Sone Yoshiharu Tamakawa Jun Nishida Masataka Abe Junichi Hachiya 《Skeletal radiology》1994,23(2):107-109
Five cases of cavernous hemangioma with fluid-fluid levels on magnetic resonance imaging and/or computed tomography are reported. The signal characteristics were those of blood and histological analysis of the fluid-fluid levels showed that they were blood-filled cavities in the tumor. Although this finding itself is not specific, it may help in confirming the diagnosis of cavernous hemangioma. 相似文献
60.
The knee meniscus exhibits extensive spatial variations in native healing capacity, biochemical composition, and cell morphology that suggest the existence of distinct phenotypes for meniscus cells. Constitutive gene expression levels of appropriate extracellular matrix proteins may serve as useful molecular markers of cellular phenotypes; however, relatively little is known of variations in the gene expression for meniscus cells of different regions of the tissue. The objective of the present study was to evaluate constitutive differences between radial inner and outer regions in gene expression for extracellular matrix proteins relevant to the meniscus. A secondary objective was to determine if these region-specific differences in gene expression are maintained after periods of monolayer culture. The innermost regions of the meniscus were found to constitutively express higher mRNA levels for proteins highly expressed in articular cartilage, including aggrecan, type II collagen, and NOS2. In contrast, the outer meniscus was found to contain higher gene expression for proteins associated with fibrous tissues including type I collagen, and the proteases MMP2 and MMP3. Isolated inner and outer meniscus cells maintained these region-specific gene expression patterns for collagens and proteoglycans during short-term monolayer culture. The results provide new information that suggests the utility of constitutive gene expression levels as molecular markers to distinguish tissue and cells of the inner and outer meniscus. 相似文献