全文获取类型
收费全文 | 207388篇 |
免费 | 18362篇 |
国内免费 | 4379篇 |
专业分类
耳鼻咽喉 | 3248篇 |
儿科学 | 4052篇 |
妇产科学 | 3569篇 |
基础医学 | 16521篇 |
口腔科学 | 7175篇 |
临床医学 | 19102篇 |
内科学 | 19717篇 |
皮肤病学 | 2384篇 |
神经病学 | 10254篇 |
特种医学 | 5653篇 |
外国民族医学 | 11篇 |
外科学 | 20157篇 |
综合类 | 33216篇 |
现状与发展 | 9篇 |
一般理论 | 24篇 |
预防医学 | 27619篇 |
眼科学 | 1981篇 |
药学 | 20029篇 |
333篇 | |
中国医学 | 26111篇 |
肿瘤学 | 8964篇 |
出版年
2024年 | 788篇 |
2023年 | 4010篇 |
2022年 | 7351篇 |
2021年 | 10256篇 |
2020年 | 9918篇 |
2019年 | 11287篇 |
2018年 | 10001篇 |
2017年 | 8586篇 |
2016年 | 7641篇 |
2015年 | 7121篇 |
2014年 | 14095篇 |
2013年 | 14310篇 |
2012年 | 12631篇 |
2011年 | 13500篇 |
2010年 | 10855篇 |
2009年 | 9375篇 |
2008年 | 8661篇 |
2007年 | 8755篇 |
2006年 | 7443篇 |
2005年 | 6301篇 |
2004年 | 5229篇 |
2003年 | 4655篇 |
2002年 | 3572篇 |
2001年 | 2973篇 |
2000年 | 2640篇 |
1999年 | 2154篇 |
1998年 | 1718篇 |
1997年 | 1548篇 |
1996年 | 1248篇 |
1995年 | 1194篇 |
1994年 | 1088篇 |
1993年 | 965篇 |
1992年 | 876篇 |
1991年 | 805篇 |
1990年 | 701篇 |
1989年 | 681篇 |
1988年 | 632篇 |
1987年 | 568篇 |
1986年 | 522篇 |
1985年 | 1776篇 |
1984年 | 2051篇 |
1983年 | 1285篇 |
1982年 | 1705篇 |
1981年 | 1180篇 |
1980年 | 1010篇 |
1979年 | 902篇 |
1978年 | 736篇 |
1977年 | 552篇 |
1976年 | 693篇 |
1975年 | 477篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
军队官兵演习后期的心理变化 总被引:2,自引:1,他引:1
为探讨军队官兵在演习后期的心理变化,本分析了军队官兵在演习后期存在放松心理,思乡情绪,自我肯定以及发泄心理等的原因,并提出了相关对策;为稳定演习官兵的思想情绪提供参考。 相似文献
972.
Summary. A prevalence study of Ureaplasma urealyticum (UU) infection of the male genital tract was carried out in Shanghai between March 1992 and June 1995. Significantly higher frequency of UU infection was found among infertile males (549/1416) as compared to fertile controls (34/375). Examination of 8 specimens each from infertile men and fertile subjects by electron microscopy, immunogold and immunofluorescence techniques, demonstrated adhesion of Ureaplasma urealyticum to the membrane of spermatozoa and exfoliated germ cells. In addition, gold particles on Ureaplasma urealyticum were found to be adhered to the sperm surface in 4 of the 8 samples. Strong specific anti-UU fluorescence was detected in 6 of 8 samples, mainly on the midpieces and post-acrosomal regions of the spermatozoa.
To further study the effects of Ureaplasma urealyticum on fertility, 47 male Sprague-Dawley (SD) rats were infected artificially with Ureaplasma urealyticum serotype 8 (T960). Morphological changes in the seminiferous tubules were observed 3–5 weeks after inoculation in the sacrificed animals. Dramatic impairment of spermatogenesis of both testes was found in 11 rats. Mating experiment confirmed infertility in 12 of 40 rats. Offsprings of the infected rats were significantly smaller than those of controls in terms of prenatal weights and birthweights. 相似文献
To further study the effects of Ureaplasma urealyticum on fertility, 47 male Sprague-Dawley (SD) rats were infected artificially with Ureaplasma urealyticum serotype 8 (T960). Morphological changes in the seminiferous tubules were observed 3–5 weeks after inoculation in the sacrificed animals. Dramatic impairment of spermatogenesis of both testes was found in 11 rats. Mating experiment confirmed infertility in 12 of 40 rats. Offsprings of the infected rats were significantly smaller than those of controls in terms of prenatal weights and birthweights. 相似文献
973.
磺胺噻二嗪硫酮衍生物的合成及其抑菌活性 总被引:1,自引:0,他引:1
利用药物化学骈合原理设计并合成了一系列新的3,5-二取代1,3,5-噻二嗪-2-硫酮类化合物,其结构经红外光谱,紫外光谱及元素分析证实,抑菌活性试验显示了良好的抑菌活性。 相似文献
974.
P. P. De Deyn V. Van de Velde PhD W. Verslegers J. Saerens B. A. Pickut B. Clincke R. Woestenborghs A. Van Peer 《European journal of clinical pharmacology》1992,43(6):661-662
Summary The single- and repeated-dose pharmacokinetics of sabeluzole have been determined in six elderly patients with [senile] dementia of the Alzheimer type.After a single oral dose of 10 mg sabeluzole, the peak plasma concentration was attained at 1 to 4 h; it averaged 42 ng·ml–1. On repeated dosing (10 mg b. d.), steady-state was virtually attained after 3 days of treatment. Steadystate mean trough and peak plasma concentrations fluctuated between 53 and 94 ng·ml–1. The mean terminal half-life after a single dose and at steady-state was of the order of 33 h.Sabeluzole was well tolerated and at the end of treatment, no systematic changes in blood haematology, biochemistry or urinalysis were seen. 相似文献
975.
某化工厂1987~2000年164例工伤事故调查分析 总被引:2,自引:0,他引:2
目的调查分析某化工厂工伤事故的分布规律及其危险因素,以便采取相应的预防干预措施。方法对1987~2000年该化工厂发生的工伤事故进行回顾性调查分析,建立数据库,并统计分析。结果 ①事故以轻伤为主,约占80.0%。②事故类别主要是灼烫烧伤和机械伤害,分别为工伤事故总数的35.8%、28.5%。③工伤伤害性质以骨折多见,约为总数的56.1%。④受伤工人的年龄分布以30~40岁段为主,约为总数的31.1%。⑤工伤事故原因中注意力不集中和违反操作规程分别为总数的43.0%,38.3%。结论12根据上述流行病学特点,采取相应的措施来减少工伤事故的发生。 相似文献
976.
A. V. Volodina O. M. Pozdnyakov 《Bulletin of experimental biology and medicine》1997,124(4):1025-1030
Desynchronization of myo- and angiogenesis is observed after trauma of skeletal muscles. These processes are synchronous during
prenatal development (18th day of embryogenesis).
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 10, pp. 460–465, October, 1997 相似文献
977.
To analyse the effect of concomitant cognitive or motor task performance on balance control in Parkinson's disease (PD), we performed a posturographic study in 24 PD patients and in 20 sex- and age-matched control subjects. Postural sway was measured with eyes open (EO) and eyes closed (EC) during quiet stance and during performance of calculation or motor sequence of thumb opposition to the other fingers. No difference of centre of foot pressure (COP) parameters was observed during quiet standing (either EO or EC) between patients and controls, but visual deprivation induced in both groups a worsening of postural stability. COP area was significantly increased in PD patients during dual task performance, whereas no difference of COP path and x-y axes was observed. The effects induced by the performance of cognitive or motor task were significantly more evident in PD patients with clinical evidence of postural instability (presence of prior falls in the history). This study demonstrates that dual task interference on postural control can be observed in PD patients during performance of cognitive as well as motor tasks. The balance deterioration during dual task performance was significantly enhanced in patients with history of prior falls. These findings have some implications for the strategies to be used in reducing the risk of fall in PD. 相似文献
978.
979.
980.
乳香提取物对急性非淋巴细胞白血病细胞诱导分化作用 总被引:5,自引:2,他引:3
探讨乳香提取物对急性非淋巴细胞白血病诱导分化作用,采用造血祖细胞体外培养技术研究乳香提取物对36例急性非淋巴白血病细胞诱导分化成熟。结果:诱导分化率ANLLM3(67.9±7.9)%;ANLLM2a(57.9±11.7)%。NBT还原率ANLLM3(67.8±3.9)%、ANLLM2a(59.9±9.5)%。墨汁吞噬功能:ANLLM3(56±8.9)%,ANLLM2a(59.8±8.7)%。结论:乳香提取物对急性非淋巴白血病细胞有诱导分化作用,使之诱导分化成熟,并恢复其功能 相似文献