全文获取类型
收费全文 | 141454篇 |
免费 | 12556篇 |
国内免费 | 8291篇 |
专业分类
耳鼻咽喉 | 1534篇 |
儿科学 | 2187篇 |
妇产科学 | 877篇 |
基础医学 | 11128篇 |
口腔科学 | 2185篇 |
临床医学 | 16345篇 |
内科学 | 15127篇 |
皮肤病学 | 1655篇 |
神经病学 | 4323篇 |
特种医学 | 6081篇 |
外国民族医学 | 8篇 |
外科学 | 15447篇 |
综合类 | 34456篇 |
现状与发展 | 45篇 |
一般理论 | 3篇 |
预防医学 | 13711篇 |
眼科学 | 2270篇 |
药学 | 15612篇 |
162篇 | |
中国医学 | 11160篇 |
肿瘤学 | 7985篇 |
出版年
2024年 | 1313篇 |
2023年 | 1610篇 |
2022年 | 3843篇 |
2021年 | 5158篇 |
2020年 | 4410篇 |
2019年 | 2924篇 |
2018年 | 3148篇 |
2017年 | 3684篇 |
2016年 | 3257篇 |
2015年 | 5396篇 |
2014年 | 7108篇 |
2013年 | 8536篇 |
2012年 | 12592篇 |
2011年 | 13020篇 |
2010年 | 11239篇 |
2009年 | 10111篇 |
2008年 | 10796篇 |
2007年 | 10554篇 |
2006年 | 9486篇 |
2005年 | 7851篇 |
2004年 | 5867篇 |
2003年 | 5333篇 |
2002年 | 4432篇 |
2001年 | 3722篇 |
2000年 | 2568篇 |
1999年 | 1226篇 |
1998年 | 514篇 |
1997年 | 529篇 |
1996年 | 419篇 |
1995年 | 294篇 |
1994年 | 260篇 |
1993年 | 161篇 |
1992年 | 144篇 |
1991年 | 138篇 |
1990年 | 92篇 |
1989年 | 79篇 |
1988年 | 65篇 |
1987年 | 67篇 |
1986年 | 58篇 |
1985年 | 48篇 |
1984年 | 26篇 |
1983年 | 30篇 |
1982年 | 29篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1959年 | 9篇 |
1958年 | 11篇 |
1957年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
卢楠楠 《中国医疗器械信息》2007,13(1):66-67
2006年10月31日,对于郑州和医疗器械行业是一个好日子,因为第56届中国国际医疗器械秋季博览会暨第3届中国国际医疗器械设计与制造技术展览会在期待和掌声中于郑州国际会展中心隆重开幕。这个以其造型新颖别致,富有强烈的时代感和现代感而成为郑州的标志性建筑的展览馆在金秋时节又一次盛装迎来了国内外客人。国家食品药品监督管理局医疗器械司副司长常永亨、总后卫生部药品器材局副局长石虹、国家发改委价格司医药价格处处长郭剑英等来自行业主管单位的领导,河南省省长史济春、郑州市市长赵建才、原河南省人大副主任钟力生、河南省药监局副… 相似文献
12.
Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells 总被引:3,自引:0,他引:3
Stefan Heller Andrea M. Bell Charlotte S. Denis Yong Choe A.J. Hudspeth 《Journal of the Association for Research in Otolaryngology》2002,3(4):488-498
Ca2+ signaling serves distinct purposes in different parts of a hair cell. The Ca2+ concentration in stereocilia regulates
adaptation and, through rapid transduction-channel reclosure, underlies amplification of mechanical signals. In presynaptic
active zones, Ca2+ mediates the exocytotic release of afferent neurotransmitter. At efferent synapses, Ca2+ activates the
K+ channels that dominate the inhibitory postsynaptic potential. A copious supply of diffusible protein buffer isolates the
three signals by restricting the spread of free Ca2+ and limiting the duration of its action. Using cDNA subtraction and a
gene expression assay based on in situ hybridization, we detected abundant expression of mRNAs encoding the Ca2+ buffer parvalbumin
3 in bullfrog saccular and chicken cochlear hair cells. We cloned cDNAs encoding this protein from the corresponding inner-ear
libraries and raised antisera against recombinant bullfrog parvalbumin 3. Immunohistochemical labeling indicated that parvalbumin
3 is a prominent Ca2+-binding protein in the compact, cylindrical hair cells of the bullfrog's sacculus, and occurs as well
in the narrow, peanut-shaped hair cells of that organ. Using quantitative Western blot analysis, we ascertained that the concentration
of parvalbumin 3 in saccular hair cells is approximately 3 mM. Parvalbumin 3 is therefore a significant mobile Ca2+ buffer,
and perhaps the dominant buffer, in many types of hair cell. Moreover, parvalbumin 3 provides an early marker for developing
hair cells in the frog, chicken, and zebrafish. 相似文献
13.
小包装全氟丙烷气体动力学实验研究 总被引:1,自引:0,他引:1
为检验塑料小包装全氟丙烷气体(C3F8)在不同包装和储存方法时浓度变化,将装有5~7mlC3F8的聚氯乙烯小袋,根据不同储藏温度和外包装方法随机分成四组:(1)22℃聚乙烯外包装,(2)36℃聚乙烯外包装,(3)22℃铝箔真空外包装,(4)-29℃聚乙烯外包装;每一组C3F8小袋气体存放一定时间后,应用气相色谱分析方法进行浓度测量。结果:第3组C3F8浓度最高和稳定,第2组浓度随放置时间降低最明显,第4组是临床应用气体的储藏和包装方法,其30天样本浓度和第3组相等,但放置一年时浓度降低。结果显示:塑料小包装C3F8予以铝箔真空外包装是一种可行的方法,利于C3F8运输和普及;聚乙烯外包装的C3F8,应放在-29℃保存,时间不超过一年。 相似文献
14.
15.
Victoria L Morgan Benoit M Dawant Yong Li David R Pickens 《Computerized medical imaging and graphics》2007,31(6):436-446
The objectives of this study were to use computer-generated phantoms containing real subject motion to: (1) compare the sensitivity of four commonly used fMRI software packages and (2) compare the sensitivity of three statistical analysis strategies with respect to motion correction. The results suggest that all four packages perform similarly in fMRI statistical analysis with SPM2 having slightly higher sensitivity. The most sensitive analysis technique was to perform motion correction and include the realignment parameters as regressors in the general linear model. This approach applies to all four packages examined and can be most beneficial when stimulus-correlated motion is present. 相似文献
16.
Objective: To observe the effect of Ureaplasma urealyticum (UU) infection on the IL-1α and IL-6 secretion by rat Sertoli cells. Methods: Eight 20-day-old UU-free male SD rats (average weight 40 g) were used. Under sterile condition, the testes were removed and separately digested with collagenase typeⅡand hyaluronidase. High purity Sertoli cells were then isolated and adjusted to a concentration of 8×105/mL with DMEM/Ham's F-12. In the infected group, 1 mL Sertoli cell suspension and 100 mL UU (serotype 8, T960) were introduced into one well of a 24 well culture plate. In the control group, 1 mL Sertoli cell suspension and 100 mL medium were introduced. IL-1αand IL-6 were determined in the culture supernatant with ELISA. Results: The production of IL-1αwas significantly lower and of IL-6 significantly higher in the infected than those in the control groups (P<0.01). Conclusion: UU infection reduces the IL-1αand increases the IL-6 secretion by rat Sertoli cells. UU infection is probably involved in 相似文献
17.
目的了解头孢菌素导致抗生素相关性腹泻的基本情况。方法对64例头孢菌素致抗生素相关性腹泻进行临床观察。结果本组头孢菌素致抗生素相关性腹泻以6个月~3岁年龄组发生率最高。其中第3代头孢菌素所致抗生素相关性腹泻的腹泻程度重于第1代。临床表现和实验室检查均缺乏特异性。结论头孢菌素致抗生素相关性腹泻比较常见,应引起临床医师在用药时的重视。 相似文献
18.
T L Perry V W Yong S Hansen K Jones C Bergeron J G Foulks J M Wright 《Journal of the neurological sciences》1987,81(2-3):321-331
Idiopathic Parkinson's disease (PD) may possibly be caused by one or more unidentified neurotoxins present in the environment, or formed endogenously, which progressively damage dopaminergic nigrostriatal neurons. N-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is an experimental neurotoxin which produces biochemical and neuropathological changes in humans, lower primates and mice that closely resemble those found in PD. Because the mechanisms of neuronal damage in both idiopathic PD and in the MPTP model of PD may involve free radical formation in the substantia nigra, antioxidants might protect dopaminergic neurons. Previously, we found that both alpha-tocopherol and beta-carotene partially protected mice against MPTP. However, in the experiments described in this paper, neither alpha-tocopherol nor beta-carotene, each administered in massive doses, had any demonstrable protective effect for dopaminergic nigrostriatal neurons in marmosets injected with low doses of MPTP. Without more knowledge about the identity of the neurotoxin(s) causing idiopathic PD, and their mechanism of action, it is not possible at this time to predict whether these 2 antioxidants might be clinically useful in preventing or ameliorating PD. 相似文献
19.
随着教育制度的改革,中职院校的学生面貌发生了巨大变化。面对新形势,我们应科学借鉴先进的教育理念,合理设置教育目标,为职业教育改革注入新的理念和活力。 相似文献
20.