全文获取类型
收费全文 | 12130篇 |
免费 | 663篇 |
国内免费 | 459篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 269篇 |
妇产科学 | 79篇 |
基础医学 | 1504篇 |
口腔科学 | 139篇 |
临床医学 | 1126篇 |
内科学 | 2455篇 |
皮肤病学 | 140篇 |
神经病学 | 593篇 |
特种医学 | 195篇 |
外科学 | 651篇 |
综合类 | 1815篇 |
预防医学 | 663篇 |
眼科学 | 83篇 |
药学 | 2556篇 |
5篇 | |
中国医学 | 624篇 |
肿瘤学 | 315篇 |
出版年
2024年 | 13篇 |
2023年 | 81篇 |
2022年 | 223篇 |
2021年 | 325篇 |
2020年 | 332篇 |
2019年 | 220篇 |
2018年 | 291篇 |
2017年 | 263篇 |
2016年 | 335篇 |
2015年 | 284篇 |
2014年 | 580篇 |
2013年 | 873篇 |
2012年 | 591篇 |
2011年 | 699篇 |
2010年 | 552篇 |
2009年 | 512篇 |
2008年 | 584篇 |
2007年 | 573篇 |
2006年 | 546篇 |
2005年 | 524篇 |
2004年 | 474篇 |
2003年 | 437篇 |
2002年 | 390篇 |
2001年 | 328篇 |
2000年 | 321篇 |
1999年 | 287篇 |
1998年 | 231篇 |
1997年 | 237篇 |
1996年 | 225篇 |
1995年 | 192篇 |
1994年 | 176篇 |
1993年 | 152篇 |
1992年 | 152篇 |
1991年 | 128篇 |
1990年 | 126篇 |
1989年 | 112篇 |
1988年 | 107篇 |
1987年 | 90篇 |
1986年 | 84篇 |
1985年 | 105篇 |
1984年 | 114篇 |
1983年 | 65篇 |
1982年 | 70篇 |
1981年 | 52篇 |
1980年 | 51篇 |
1979年 | 26篇 |
1978年 | 31篇 |
1977年 | 26篇 |
1976年 | 17篇 |
1974年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
目的 制备甘草蛋白免疫磁性微球,并建立快速、精确的免疫磁性捕获ELISA法检测甘草蛋白。方法 采用种子聚合法合成聚苯乙烯磁性微球,并以兔抗甘草蛋白IgG抗体致敏,制备特异性捕获甘草特征蛋白的免疫磁性微球。以生物素标记抗体为示踪抗体,结合辣根过氧化物酶标亲和素建立ELISA检测系统,用于甘草药材和含甘草中成药中甘草蛋白的分析。结果 利用该方法对甘草药材和中成药中甘草蛋白抗原检测,检测灵敏度达到10ng/mL。结论 免疫磁性捕获ELISA检测技术方便、快速、准确,为生药的品种鉴定及中成药的质量控制提供一种新方法。 相似文献
12.
Y Namba T Moriyama M Kyo K Oka Y Kokado Y Shi R Imamura N Ichimaru A Okuyama S Takahara 《Clinical transplantation》2004,18(S11):29-33
Abstract: Angiotensin-converting enzyme inhibitor (ACEI) has become recognized as agents that have renoprotective effects in the treatment of progressive renal diseases including post-transplant kidneys. Previously we demonstrated the safety and effectiveness of ACEI treatment on the hypertensive proteinuric post-transplant patients ( N = 10) who had been followed up for 12 months. However, not all patients show good response in urinary protein reduction. We aimed to analyse the histopathological factor(s) affecting the responsiveness of proteinuria to ACEI treatment. Fourteen post-transplant patients with proteinuria who were treated with ACEI and underwent allograft biopsy were analysed. Eight patients showed 50% or more reduction in proteinuria (responder). The other 6 patients showed less (< 50%) reduction in proteinuria (non-responder). There was no difference in clinical characteristics (BP, renal function, donor age, recipient body mass index), dietary sodium or protein intake, and diuretic use between the two groups. As a histopathological characteristic, glomerular size in responder group was significantly larger than that in non-responder group. This suggests that the large glomerular size at least partly contributes to the responsiveness in urinary protein reduction to ACEI treatment in kidney allograft recipients with proteinuria. 相似文献
13.
Primary cultures enriched in neurons dissociated from embryonic rat cerebra were used to demonstrate that platelet activating factor and the structurally related ether glycerolipid, dodecylglycerol, are readily taken up in small amounts by neurons and that they stimulate the differentiation of neurons. The stimulation of neuronal differentiation was observed as a precocious development of axon-like extensions which correlated with a concentration-dependent increase in neuronal-specific enzyme activities. This stimulation of morphological and neurochemical factors by either platelet activating factor or dodecylglycerol was almost completely abolished by triazolam, a known inhibitor of platelet activating factor function. Neither platelet activating factor nor dodecylglycerol at the concentrations used to achieve stimulation of neuronal differentiation compromised the plasma membrane, as indicated by the lack of leakage of cytoplasmic lactic acid dehydrogenase. 相似文献
14.
精浆抗精子抗体阳性不育患者顶体酶、一氧化氮合酶及超氧化物歧化酶活力变化的研究 总被引:2,自引:0,他引:2
目的:研究精浆抗精子抗体(AsAb)阳性对精子顶体酶、精浆一氧化氮合酶(NOS)及超氧化物歧化酶(SOD)活力的影响。方法:精浆AsAb阳性不育者40例,对照组为40例正常生育男性。通过吸光度变化分别计算顶体酶活力(BAEE/ADH联合法)、NOS活力(氧化还原反应)、SOD活力(黄嘌呤氧化酶法)。结果:精浆As-Ab阳性组与正常生育组比较,精子顶体酶活力明显降低(P<0.01),NOS活力明显升高(P<0.01),精浆中SOD活力明显降低(P<0.01)。结论:精浆AsAb阳性引起不育可能与精子顶体酶、精浆中SOD及NOS活力改变有关。 相似文献
15.
P. V. Luoma A. Rautio J. Steng»rd E. A. Sotaniemi J. Marniemi 《European journal of clinical pharmacology》1990,38(6):625-627
Summary Serum high density lipoprotein (HDL) subfractions HDL2 and HDL3, apolipoproteins, and plasma antipyrine clearance (AP-CL) rate, an index of liver microsomal enzyme activity, were determined in 21 healthy subjects. High HDL cholesterol and HDL2 cholesterol concentrations and HDL cholesterol/cholesterol and HDL2/HDL3 cholesterol ratios were associated with high AP-CL. Phenobarbital enhanced antipyrine elimination and increased the apolipoprotein A-I/A-II ratio. Subjects who had high AP-CL had a more antiatherogenic HDL subfraction and apolipoprotein profile than those with low AP-CL. 相似文献
16.
Fuyumi Yamamoto Hiroshi Kasai Tadayoshi Bessho Myung-Hee Chung Hideo Inoue Eiko Ohtsuka Tomokatsu Hori Susumu Nishimura 《Cancer science》1992,83(4):351-357
Here we report the finding of enzymatic activity that specifically cleaves DNA containing 8-hydroxyguanine (oh8 Gua) residues in various mammalian cells. To detect this activity, we used a synthetic double-stranded DNA containing a single oh8 Gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. Two cleavage sites near the oh8 Gua residue were detected with partially purified fractions from cow brain and rat liver, and also with preparations from all mammalian tissues examined. These results suggest that enzymatic activity for the removal of oh8 Gua from DNA is widely distributed in mammalian cells. 相似文献
17.
使用ELISA双抗夹心法对临床43例造血系统恶性肿瘤患者及20例健康体检人员的血清sIL-2R进行检测,并对ALL和ANLL复发与未复发患者的血清sIL-2R水平进行了比较分析。实验结果表明,血清sIL-2R水平的升高是造血系统恶性肿瘤的重要标志之一;测定血清sIL-2R水平对造血系统恶性肿瘤的辅助诊断、疗效观察及预后估计具有重要意义。 相似文献
18.
19.
We describe how adverse drug reactions (ADRs) can play an important role in pharmaceutical research and drug development. Not only do ADRs represent the risks and drawbacks associated with drugs but they can also be related to other knowledge available in pharmaceutical and medical research. We offer a model that can be used to systematically map the pathways through which ADRs can lead to innovative research. These pathways include chemical, therapeutic or pathophysiological steps that can be taken to arrive at new knowledge based on ADRs. We used the development of angiotensin-converting enzyme inhibitors, especially captopril, as a case study. The similarity between the ADR profiles of captopril and penicillamine was a starting point for further innovation. Historical analysis shows that in several instances research in the field of angiotensin-converting enzyme inhibitors has been triggered by ADRs. The model presented here might be applicable to other areas of innovative drug research. 相似文献
20.
作者综述了10年来对Duchenne型肌营养不良症(DMD)的研究概况。主要包括①DMD的临床研究。②血清生化研究表明CK、LDH、Mb是诊断DMD病人和携带者的敏感指标。③心脏无创性检测和肌肉超微结构研究。④部分抗肌萎缩蛋白基因YAC物理图谱,精细限制酶图谱和缺失热区的核苷酸顺序分析,首次发现内含子中AT富集区的同源顺序与DMD断裂有关。⑤抗肌萎缩蛋白的缺失热区疏水肽段存在与否与DMD发病密切相关。 相似文献