全文获取类型
收费全文 | 24568篇 |
免费 | 2151篇 |
国内免费 | 595篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 558篇 |
妇产科学 | 429篇 |
基础医学 | 2755篇 |
口腔科学 | 349篇 |
临床医学 | 2627篇 |
内科学 | 3507篇 |
皮肤病学 | 243篇 |
神经病学 | 691篇 |
特种医学 | 383篇 |
外国民族医学 | 2篇 |
外科学 | 1500篇 |
综合类 | 3299篇 |
现状与发展 | 4篇 |
一般理论 | 1篇 |
预防医学 | 4567篇 |
眼科学 | 184篇 |
药学 | 3529篇 |
17篇 | |
中国医学 | 1311篇 |
肿瘤学 | 1292篇 |
出版年
2024年 | 52篇 |
2023年 | 324篇 |
2022年 | 738篇 |
2021年 | 1001篇 |
2020年 | 815篇 |
2019年 | 825篇 |
2018年 | 766篇 |
2017年 | 845篇 |
2016年 | 882篇 |
2015年 | 980篇 |
2014年 | 1520篇 |
2013年 | 1804篇 |
2012年 | 1377篇 |
2011年 | 1570篇 |
2010年 | 1210篇 |
2009年 | 1029篇 |
2008年 | 1024篇 |
2007年 | 1035篇 |
2006年 | 996篇 |
2005年 | 808篇 |
2004年 | 724篇 |
2003年 | 672篇 |
2002年 | 556篇 |
2001年 | 442篇 |
2000年 | 395篇 |
1999年 | 275篇 |
1998年 | 302篇 |
1997年 | 301篇 |
1996年 | 266篇 |
1995年 | 255篇 |
1994年 | 269篇 |
1993年 | 235篇 |
1992年 | 224篇 |
1991年 | 192篇 |
1990年 | 170篇 |
1989年 | 172篇 |
1988年 | 146篇 |
1987年 | 159篇 |
1986年 | 119篇 |
1985年 | 353篇 |
1984年 | 270篇 |
1983年 | 235篇 |
1982年 | 206篇 |
1981年 | 183篇 |
1980年 | 137篇 |
1979年 | 91篇 |
1978年 | 84篇 |
1977年 | 67篇 |
1976年 | 48篇 |
1975年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
F. R. VOGELPOEL R. J. VAN KOOIJ E. R. TE VELDE J. VERHOEF 《International journal of andrology》1990,13(2):81-86
Isolated sperm from normo-, oligo- and astheno-spermic men were incubated for 20 h in medium supplemented with 8% heat-inactivated or untreated human serum, and in medium with heated or untreated serum deficient in complement factor C3. Before and after incubation, sperm motility was assessed by means of a computer-assisted semen analyser. The results did not show significant differences between the motility of sperm incubated in heated or untreated serum. It is concluded that heating of homologous serum is not necessary for preserving sperm motility and in some cases may even be disadvantageous. 相似文献
42.
慢性病信息系统的指标及其收集方法的研究 总被引:2,自引:0,他引:2
目的 探讨我国目前慢性病监测系统应监测的指标、指标的收集方法。方法 DELPHI专家咨询法。结果 目前社区慢性病综合防治信息系统包括的指标有六方面内容,按照平均重要程度等级和排位的结果是死亡监测、发病或患病监测、危险因素监测、社区环境监测、疾病管理与卫生经济监测;指标的收集渠道应统一协调卫生系统的各个部门,包括医院、社区和各级疾病预防控制机构(CDC)以及公安和民政等部门;指标的收集方式主要依靠常规报告,部分指标通过流行病学调查来获得;监测指标的用途主要用于探测慢性病流行趋势和引起的疾病负担、确定防治重点、评价慢性病干预效果,以便更有效的防治慢性病;如何确保监测资料的质量和政府提供必须的费用是监测中比较普遍存在的问题。结论 死亡监测、发病或患病监测、行为危险因素监测应是慢性病综合防治信息系统应首选的内容。 相似文献
43.
44.
45.
服用左炔诺孕酮滴丸和妈富隆1年对血压、血糖和血脂的影响 总被引:1,自引:0,他引:1
杨玉健 《天津医科大学学报》2003,9(3):373-377
目的:观察第二、三代口服避孕药(COC)对育龄妇女体重指数、血压、血糖和血脂的影响。方法:将自愿服用COC避孕1年的妇女105例随机分为两组,其中54例给予第二代COC(EE/LNG组),51例给予第三代COC(EE/DG组)。并对研究前后所有病例的体重指数(BMI)、血压、血糖和血脂代谢指标进行比较分析。结果:EE/LNG组:BMI、收缩压、舒张压、甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL)和载脂蛋白B(ApoB)水平均升高,高密度脂蛋白(HDL)水平下降,血糖、载脂蛋白AI(ApoAI)水平无明显改变。EE/DG组收缩压、TG、HDL水平升高,BMI、舒张压、血糖、TC、LDL、ApoAI和ApoB均未发生显著变化。以上所有测量指标均未超出正常范围。结论:使用1年第二、三代COC对妇女BMI、血压和血脂代谢都有微弱的影响,对空腹血糖无明显影响。第三代COC对妇女BMI、收缩压、舒张压、TG、TC、LDL、HDL水平和ApoB的不利影响小于第二代,更加安全可靠。 相似文献
46.
G Kellner T Popow-Kraupp C Binder I Goedl M Kundi C Kunz 《Journal of medical virology》1991,35(4):267-272
Rhinoviruses were isolated from nasopharyngeal secretions of 49 children hospitalized because of severe respiratory tract infection. The isolates were typed using 90 type-specific antisera. No obvious relation between certain serotypes and the severity of illness was found. Serum samples were drawn from all children simultaneously with the nasopharyngeal secretions and screened for the presence of type-specific neutralizing antibodies. Children aged 1 week to 6 months had higher neutralizing antibody titers and revealed a lower degree of morbidity than older children. The decline of neutralizing serum antibodies with increasing age was correlated with a higher incidence of severe disease in those aged 7-12 months. Nevertheless, also in this age group children with mild clinical courses of disease were observed despite a low concentration or an absence of neutralizing serum antibodies. This indicates that not only neutralizing serum antibodies, but other factors also influence the clinical expression of RHV-induced disease. 相似文献
47.
缺锌对大鼠力竭性游泳前后睾酮和锌水平变化的影响 总被引:5,自引:1,他引:4
本实验动态观察了缺锌和缺锌后补锌对大鼠力竭性游泳前后辜丸和血清睾酮、锌水平以及游泳能力的影响。结果显示:缺锌造成大鼠游泳能力大大降低,补锌后明显增加。不论安静时还是力竭性游泳后12小时内,缺锌大鼠的血清和辜丸锌含量均显著低于对照和补锌大鼠。与对照和补锌大鼠相比,缺锌大鼠的血清和睾丸酮含量,安静时均较低,力竭性游泳后也呈现不同程度的降低。缺锌还造成大鼠辜丸重量的明显下降。结果表明,锌营养不良将损害运动能力。 相似文献
48.
目的 :探讨奶茶对大鼠体重和血清胆固醇含量的影响。方法 :将大鼠随机分为对照、脂对照、奶、茶和奶茶五组 ;高脂饲养的同时分别用水、奶、茶和奶茶进行灌胃 ,定期测定大鼠的血清胆固醇 (TC)。结果 :实验期间奶茶组大鼠体重的增长量高于其他三个高脂饲料组 ,且明显高于对照组 (P <0 .0 5 ) ;高脂饲料组大鼠的血清胆固醇含量明显增加 ,但增长量在高脂饲料组间差异无显著性 (P >0 .0 5 )。结论 :本实验浓度的奶茶对高脂饲料诱导的大鼠血清胆固醇升高未见有降低作用 相似文献
49.
A. Sklavounou-Andrikopoulou E. Chrysomali M. Iakovou G. A. Garinis A. Karameris 《Journal of oral pathology & medicine》2004,33(7):386-390
BACKGROUND: The serum circulatory levels of apoptosis related molecules measured in patients with oral lichen planus (OLP) and healthy individuals in order to investigate possible alterations associated with the clinical forms of OLP. METHODS: Serum levels of tumor necrosis factor (TNF)-alpha, soluble Fas (sFas) and Bcl-2 studied by enzyme-linked immunosorbent assay in whole blood samples in 13 OLP reticular, 13 OLP atrophic-erosive form patients and 26 healthy subjects. RESULTS: Significantly elevated levels of TNF-alpha and sFas detected in OLP patients as compared with controls. Serum concentrations of Bcl-2 although increased in 17/26 patients, they were not statistically significant. Reticular OLP exhibited slightly elevated TNF-alpha and significantly elevated Bcl-2 serum levels, compared with erosive OLP. CONCLUSIONS: These data suggest that a putative dysfunction in the Fas/FasL mediated apoptosis might be involved in the OLP pathogenesis. A downregulation of Bcl-2 serum levels in the atrophic-erosive OLP may be associated with promotion of the disease activity. 相似文献
50.
Temperature sensitive liposomes (TSL) containing adriamycin (ADM) and cytarabine (Ara-C) were prepared. ADM and Ara-C were
selected as model compounds of amphiphilic and hydrophilic drug, respectively. Encapsulation efficiency of ADM entrapped into
TSL was about twice greater than that of Ara-C. It might be due to different polarity of the drugs. Lipid compositions of
TSL had no effect on the encapsulation efficiency of drugs. Thermal behavior of TSL using a differential scanning calorimetry
(DSC) was also investigated. Phase transition temperature (Tc) of TSL was dependent on the lipid compositions of TSL.ADM broadened thermogram of TSL but Ara-C did not. However, Tc of TSL was not changed by any drug. Release rate of drugs was highly dependent on temperature. The release profile of ADM
was similar to that of Ara-C. The maximum release rate of drugs from TSL was occurred at the near Tc and observed at 39–41°C for DPPC (Dipalmitoylphosphatidylcholine) only, 52–54°C for DSPC (Distearoylphosphatidylcholine)
only, 41–43°C for DPPC and DSPC (3∶1), and 43–45°C for DPPC and DSPC (1∶1), respectively. Effect of human serum albumin (HSA)
on the release rate of ADM was investigated. HSA had no significant effect on the release of ADM below Tc. However, ADM release from TSL was increased at the near and above Tc. The HSA-induced leakage of drug may result from the interaction of liposomal constituents with HSA structure at the near
Tc. From the fact that the release profiles of ADM from freshly prepared TSL and stored TSL for 1 week at 4°C was not changed,
the TSL was considered to be stable for at least 1 week at 4°C. Based on these findings, TSL may be useful to deliver drugs
to preheated target sites due to its thermal behaviors. 相似文献