全文获取类型
收费全文 | 171309篇 |
免费 | 3650篇 |
国内免费 | 1978篇 |
专业分类
耳鼻咽喉 | 1754篇 |
儿科学 | 6129篇 |
妇产科学 | 2720篇 |
基础医学 | 19657篇 |
口腔科学 | 4484篇 |
临床医学 | 11889篇 |
内科学 | 31979篇 |
皮肤病学 | 2926篇 |
神经病学 | 10124篇 |
特种医学 | 3506篇 |
外国民族医学 | 1篇 |
外科学 | 26784篇 |
综合类 | 10695篇 |
一般理论 | 4篇 |
预防医学 | 9770篇 |
眼科学 | 3383篇 |
药学 | 18847篇 |
27篇 | |
中国医学 | 7606篇 |
肿瘤学 | 4652篇 |
出版年
2022年 | 1364篇 |
2021年 | 2622篇 |
2020年 | 1336篇 |
2019年 | 12794篇 |
2018年 | 12470篇 |
2017年 | 5665篇 |
2016年 | 1301篇 |
2015年 | 1281篇 |
2014年 | 3071篇 |
2013年 | 4959篇 |
2012年 | 3153篇 |
2011年 | 3187篇 |
2010年 | 2699篇 |
2009年 | 2613篇 |
2008年 | 3076篇 |
2007年 | 4157篇 |
2006年 | 4328篇 |
2005年 | 4212篇 |
2004年 | 3291篇 |
2003年 | 3362篇 |
2002年 | 3226篇 |
2001年 | 3193篇 |
2000年 | 3420篇 |
1999年 | 3080篇 |
1998年 | 3133篇 |
1997年 | 2456篇 |
1996年 | 2301篇 |
1995年 | 2649篇 |
1994年 | 2472篇 |
1993年 | 1930篇 |
1992年 | 1536篇 |
1991年 | 1517篇 |
1990年 | 1261篇 |
1989年 | 1009篇 |
1988年 | 1041篇 |
1987年 | 1008篇 |
1986年 | 836篇 |
1985年 | 5420篇 |
1984年 | 7289篇 |
1983年 | 5832篇 |
1982年 | 6267篇 |
1981年 | 5722篇 |
1980年 | 4918篇 |
1979年 | 4964篇 |
1978年 | 4070篇 |
1977年 | 3053篇 |
1976年 | 3526篇 |
1975年 | 2734篇 |
1974年 | 2525篇 |
1973年 | 2229篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
181.
182.
从1985年起,应用胫骨骨条植骨结合多根克氏针内固定治疗股骨颈骨折21例,经随访7个月—48个月,优17例、良3例、差1例。通过临床观察,用自体胫骨骨条植骨提供活的骨细胞及诱导成骨,能促进加速骨折愈合。本手术方法简单、安全 相似文献
183.
We describe a simple direct extraction method for the gas-liquid chromatography determination of serum valproic acid. The working range for the assay is 2-180 mg/L and our within-run precision was 5.8 and 4.3% at the 40 and 90 mg/L concentrations respectively. Hemolyzed and lipemic sera as well as samples from patients with hyperbilirubinemia and from patients with decreased renal function were put through the assay and no interfering peaks were noted. Interference occurred when teflon-lined screw caps were used during the extraction step. The method was proven to be accurate by linear regression analysis of samples containing weighed-in amounts of valproic acid. The above assay was compared to an enzyme immunoassay technique (EMIT). The working range for the latter is 10-150 mg/L and the with-run precision was 10.8 and 5.9% and 90 mg/L concentration respectively. Samples were run by both the gas-liquid chromatograph and enzyme immunoassay methods and gave very similar results over the range 16-139 mg/L. 相似文献
184.
185.
Long-term neurotoxicity of chlorpyrifos: spatial learning impairment on repeated acquisition in a water maze. 总被引:2,自引:0,他引:2
Fernando Ca?adas Diana Cardona Eva Dávila Fernando Sánchez-Santed 《Toxicological sciences》2005,85(2):944-951
Organophosphate compounds are cholinesterase inhibitors widely used in agriculture, industry, household products, and even as chemical weapons. Their major mechanism of acute toxic action is the inhibition of acetylcholinesterase, which is responsible for the degradation of the neurotransmitter acetylcholine. An organophosphorus ester-induced chronic neurotoxicity (OPICN) syndrome has been proposed. The OPICN syndrome could result from both long-term exposure to subclinical doses of OPs and after acute poisoning. Development of animal models for the cognitive decline are required and could later help to elucidate the mechanisms involved in this long-term effect on the central nervous system. Previously, we have found performance decrements in a four-trial repeated acquisition spatial task in a water maze. The present study includes two experiments to extend the long-term behavioral effects observed. Rats were injected either once or twice with chlorpyrifos (CPF) and then tested months after in a two-trial repeated acquisition task in a water maze. Our results confirm and extend the long-term behavioral effects of subcutaneous administration of CPF. The two treatments used produced performance decrements that suggest functional central nervous system alterations. 相似文献
186.
A HIGH FREQUENCY OF INHERITED DEFICIENCY OF COMPLEMENT COMPONENT C4 IN DARWIN ABORIGINES 总被引:2,自引:0,他引:2
Abstract A high frequency of serum complement component C4A deficiency may explain the higher prevalence and greater severity of systemic lupus erythematosus reported in Australian Aborigines. Inherited deficiencies of serum complement components C4A, C4B, and C2 were examined in two Australian Aboriginal populations from Darwin and Alice Springs and compared with the prevalence of complement deficiencies in white Australian blood donors. The frequency of C4A deficiency alleles was 29% in Darwin Aborigines compared with 12% in Alice Springs and 17% in Canberra blood donors. Partial C4B deficiency was also higher in Darwin Aborigines than in the other populations. Inherited deficiency of serum complement component C2 was not observed. 相似文献
187.
目的:优选散结消肿贴中大黄、重楼的渗漉提取工艺。方法:以总固体物得率和总蒽醌得率为指标,用正交实验优选。结果:工艺中影响最大的因素是乙醇浓度,其次是乙醇用量,浸泡时间影响较小。最佳工艺条件为乙醇浓度65%,乙醇用量8倍量。浸泡时间24h。结论:渗漉法操作简单,成份破坏少,用优选所得条件进行提取,总蒽醌和总固体物得率均较高,优选结果可用于散结消肿贴中大黄、重楼的提取。 相似文献
188.
189.
蛇床子水提取液抑瘤作用的实验研究 总被引:13,自引:0,他引:13
目的 :研究蛇床子水提取液的体内抗肿瘤作用。方法 :通过 S180 肉瘤移植建立荷瘤小鼠模型 ,给予不同剂量蛇床子水提取液后观察 S180 荷瘤小鼠肿瘤生长曲线、血清唾液酸 (SA)、瘤重及小鼠生存天数的变化。结果 :蛇床子水提取液能明显抑制肿瘤生长 ,降低荷瘤小鼠血清 SA水平 ,0 .0 6mg/(g· d) ,0 .1 1 mg/(g· d)、0 .2 1 mg/(g· d)剂量组平均瘤重低于肿瘤对照组 (P<0 .0 5 ) ,抑瘤率依次为 2 3 .2 %、2 9.1 %和 2 4 .8%,且能延长荷瘤小鼠生存天数 (P<0 .0 1 ) ,动物生命延长率依次为 :2 6 .9%、3 4 .8%和 2 6 .6 %。结论 :蛇床子水提取液具有较强的抗肿瘤效应 ,有很好的利用前景 ,值得对其进行深入研究。 相似文献
190.
护理工作中院内感染相关问题与对策 总被引:5,自引:2,他引:3
目的 :提出护理工作与院内感染相关问题与对策。方法 :通过监测 ,找出护理工作引起院内感染存在的问题及薄弱环节 ,并制定相应对策。结果 :建立严格的控制感染的管理制度 ,层层落实把关 ,主动和独立地判断出行之有效的预防措施。结论 :在感染管理工作中严格认真执行消毒、灭菌、无菌操作 ,最大限度地避免因护理工作失误而引起的医院内感染 相似文献