全文获取类型
收费全文 | 2307篇 |
免费 | 197篇 |
国内免费 | 107篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 50篇 |
妇产科学 | 6篇 |
基础医学 | 237篇 |
口腔科学 | 153篇 |
临床医学 | 100篇 |
内科学 | 277篇 |
皮肤病学 | 624篇 |
神经病学 | 42篇 |
特种医学 | 31篇 |
外科学 | 87篇 |
综合类 | 340篇 |
现状与发展 | 1篇 |
预防医学 | 235篇 |
眼科学 | 15篇 |
药学 | 344篇 |
中国医学 | 33篇 |
肿瘤学 | 32篇 |
出版年
2024年 | 1篇 |
2023年 | 22篇 |
2022年 | 77篇 |
2021年 | 98篇 |
2020年 | 53篇 |
2019年 | 51篇 |
2018年 | 76篇 |
2017年 | 71篇 |
2016年 | 100篇 |
2015年 | 93篇 |
2014年 | 143篇 |
2013年 | 184篇 |
2012年 | 150篇 |
2011年 | 164篇 |
2010年 | 127篇 |
2009年 | 90篇 |
2008年 | 107篇 |
2007年 | 86篇 |
2006年 | 80篇 |
2005年 | 63篇 |
2004年 | 64篇 |
2003年 | 53篇 |
2002年 | 45篇 |
2001年 | 44篇 |
2000年 | 22篇 |
1999年 | 32篇 |
1998年 | 41篇 |
1997年 | 30篇 |
1996年 | 41篇 |
1995年 | 43篇 |
1994年 | 31篇 |
1993年 | 29篇 |
1992年 | 38篇 |
1991年 | 33篇 |
1990年 | 32篇 |
1989年 | 29篇 |
1988年 | 26篇 |
1987年 | 22篇 |
1986年 | 19篇 |
1985年 | 20篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 14篇 |
1981年 | 3篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 4篇 |
排序方式: 共有2611条查询结果,搜索用时 15 毫秒
1.
对某镍业公司车间空气中镍浓度和工人指甲镍含量进行了测定。按照生产过程和卫生学特点,将所获数据划分为碎矿压球、电炉转炉和汽车维修三组。空气镍浓度几何均值分别为0.0978、0.0623和0.0202mg/m~3;工人指甲镍几何均值分别为23.04、21.07和4.84μg/g;两者呈现一定的接触水平-反应关系。表明以指甲镍作为职业性接镍人群的生物监测指标有一定的参考价值。 相似文献
2.
3.
$BasicCollegeofmedicalScienes;InstituteofEndemicDiseases 相似文献
4.
Patch testing was carried out in 851 atopic patients; 181 atopic dermatitis (AD) patients were additionally tested with 50% dilutions of the test substances. The occurrence of allergic and irritant reactions was frequent, being 57% and 33% for AD patients aged 28-41 years and 19-27 years, respectively. Among age-matched allergic rhinitis (AR)/allergic conjunctivitis (AC) or asthma (A) patients, the number of allergic reactions varied from 25 to 30%, and for irritant reactions was 24%. In all groups, nickel, fragrance-mix, balsam of Peru and neomycin were the commonest allergens. Contact allergy to ingredients of topical medicaments was common among AD patients and patients with severe and long-lasting dermatitis were most frequently sensitized. However, sensitivity to multiple substances was not common among those patients. The number of irritant reactions was considerable, but 50% dilution of the test substances did not solve the problem. 相似文献
5.
6.
The histological distinction between carcinosarcoma and mesothelioma has received little attention. The object of this study was to describe the histology and immunohistochemistry of two carcinosarcomas presenting as pleural tumours. These were compared with 12 carcinosarcomas from sites within the lung, and with the established features of mesothelioma. Histologically and immunohistochemically, these 'pleural' carcinosarcomas are similar to conventional pulmonary carcinosarcomas but accurate recognition is hindered by their gross appearance and biphasic histology which closely mimic mesothelioma. They may exhibit features such as neutral mucin, expression of carcinoembryonic antigen, squamous differentiation, and neuroendocrine differentiation which, when present, are evidence against mesothelioma. These tumours are rare and have passed unnoticed until now. 相似文献
7.
8.
二乙基二硫代氨基甲酸钠驱镍作用的实验研究 总被引:1,自引:0,他引:1
本文用大鼠研究了带-SH基的二乙基二硫代氨基甲酸钠(Dithiocarb,简称Na-DDC或称铜试剂)和不带-SH基的新螯合剂(H-73-10)的驱镍作用。结果表明,Na-DDC对羰基镍(Ni(CO)_4〕的驱镍作用明显优于H-73-10;与此相反,H-73-10对硝酸镍〔Ni(NO_3)_2〕染毒大鼠的驱镍作用却明显优于Na-DDC。 相似文献
9.
M. W. Warenycia K. A. Smith C. S. Blashko S. B. Kombian R. J. Reiffenstein 《Archives of toxicology》1989,63(2):131-136
Administration of sodium hydrosulfide (NaHS), an alkali salt of hydrogen sulfide (H2S) at doses of 10 and 30 mg/kg, corresponding to sublethal and lethal doses (0.66 and 2.0 X LD50) resulted in significant increases in regional catecholamine levels of the rat brain only after the dose of 2.0 × LD50 of NaHS. Whereas the cortex and the cerebellum showed little or no change in catecholamine content, the hippocampus, striatum and brainstem all showed increases in noradrenaline and adrenaline. Additional analysis also showed that brainstem dopamine and 5-hydroxytryptamine levels (5-HT) increased as well. In vitro testing of sulfide for inhibition of monoamine oxidase (MAO) activity showed the anion to be inhibitory with an IC50 of 39.1±3.6 M. Inhibition of MAO activity ex vivo could be demonstrated at a dose of 100 mg/kg but not at the lower dose of 30 mg/kg NaHS. Inhibition of enzyme activity could not be demonstrated at this lower dose, possibly due to the well known rapid intramitochondrial metabolism of sulfide. Correlation of synaptosomal and mitochondrial sulfide levels with enzyme inhibition data suggests that inhibition of MAO may be an important contributing factor to the mechanism(s) underlying loss of central respiratory drive after fatal intoxication with H2S. 相似文献
10.
Pigments of the Gastrointestinal Tract: A Comparison of Light Microscopic and Electron Microscopic Findings 总被引:6,自引:0,他引:6
It is now apparent that light microscopy and histochemistry failed to identify correctly the nature and composition of pigments in various gastrointestinal tract melanoses. In most instances it was thought that the pigment was melanin or a melanin-like substance. Electron microscopy (EM) and electron-probe energy dispersive x-ray analysis have rectified these errors and have shown the following: in melanosis coli the pigment granules contain lipofuscin; in melanoses ilei the pigment granules may contain either silicates and titanium or hemosiderin; and in melanosis duodeni the pigment granules contain iron sulfide. In melanosis esophagi it is not clear what the pigment is; it could be melanin or lipofuscin. 相似文献