全文获取类型
收费全文 | 36025篇 |
免费 | 1937篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 438篇 |
儿科学 | 2137篇 |
妇产科学 | 707篇 |
基础医学 | 4591篇 |
口腔科学 | 811篇 |
临床医学 | 2523篇 |
内科学 | 7316篇 |
皮肤病学 | 839篇 |
神经病学 | 1902篇 |
特种医学 | 855篇 |
外科学 | 4962篇 |
综合类 | 1331篇 |
一般理论 | 15篇 |
预防医学 | 2107篇 |
眼科学 | 1544篇 |
药学 | 3507篇 |
中国医学 | 274篇 |
肿瘤学 | 2212篇 |
出版年
2023年 | 236篇 |
2022年 | 670篇 |
2021年 | 1156篇 |
2020年 | 637篇 |
2019年 | 855篇 |
2018年 | 1047篇 |
2017年 | 722篇 |
2016年 | 954篇 |
2015年 | 990篇 |
2014年 | 1351篇 |
2013年 | 1753篇 |
2012年 | 2407篇 |
2011年 | 2427篇 |
2010年 | 1375篇 |
2009年 | 1240篇 |
2008年 | 1768篇 |
2007年 | 1741篇 |
2006年 | 1757篇 |
2005年 | 1384篇 |
2004年 | 1384篇 |
2003年 | 1176篇 |
2002年 | 1001篇 |
2001年 | 825篇 |
2000年 | 868篇 |
1999年 | 732篇 |
1998年 | 316篇 |
1997年 | 225篇 |
1996年 | 232篇 |
1995年 | 229篇 |
1994年 | 184篇 |
1993年 | 164篇 |
1992年 | 500篇 |
1991年 | 405篇 |
1990年 | 433篇 |
1989年 | 402篇 |
1988年 | 367篇 |
1987年 | 366篇 |
1986年 | 354篇 |
1985年 | 326篇 |
1984年 | 262篇 |
1983年 | 220篇 |
1982年 | 141篇 |
1979年 | 231篇 |
1978年 | 150篇 |
1977年 | 183篇 |
1975年 | 171篇 |
1974年 | 182篇 |
1973年 | 182篇 |
1972年 | 173篇 |
1971年 | 161篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Buprenorphine was introduced as a potent analgesic with low abuse potential. Reports of buprenorphine abuse by opiate abusers have accumulated over the years, highlighting its use as a cheap alternative to heroin. The lower potency compared with heroin is being compensated by using a cocktail of buprenorphine with benzodiazepines or cyclizine. This study of 18 cases seen over 3 years broadly confirms these findings. Four cases reported haematemesis during acute withdrawal, a symptom not reported in earlier studies. 相似文献
52.
53.
T K Singh 《Acta cardiologica》1992,47(4):321-329
Serum ceruloplasmin levels were estimated in 81 patients within one week after an attack of acute myocardial infarction. A total of 126 healthy subjects were taken as controls and investigated for this copper containing protein. Results showed that there is an elevation in the levels of serum ceruloplasmin in patients as compared to the controls. Ceruloplasmin levels showed a return to almost normal values in 54 follow-up cases of acute myocardial infarction during the fourth week after infarction. 相似文献
54.
55.
56.
A B Singh P Malik D Parkash C K Gupta 《Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand》1992,10(2):103-109
Standardization of allergens are achieved by in vitro and in vivo methods. Some of the allergens from Western countries are standardized using biological potency of the extracts but no attempt has been made till now to standardize any of the pollen extracts from India based on biological units. Therefore, we have attempted to standardize two important pollen allergens Ricinus communis and Holoptelea integrifolia by biological methods. Broadly the methods adopted by Dreborg and Grimmer (1983) was followed. Skin prick tests were carried out with the extracts of R. communis and H. integrifolia on 15 allergic patients in five three fold log dilutions starting with 1:10, in 50% glycerinated buffer. Glycerinated buffer (50%) and histamine dihydrochloride (1 mg/ml) were used as negative and positive controls, respectively. The mean wheal diameter obtained with different concentrations showed a gradual systematic fall with increase in dilution. The mean relative diameter (% of histamine reaction) varied from 124.1 +/- 8.9 to 33.7 +/- 6.1 and 78.9 +/- 5.5 to 21.4 +/- 3.8 with the highest and lowest concentrations of R. communis and H. integrifolia pollen antigens, respectively. The histamine equivalent concentration of antigen 1,000 Biological Units (BU) obtained for crude pollen extracts of R. communis and H. integrifolia was 1:17 and 1:22 respectively. 相似文献
57.
K. M. Bijli† B. P. Singh S. Sridhara S. N. Gaur‡ N. Arora 《Clinical and experimental allergy》2003,33(1):65-71
BACKGROUND: Allergen extracts are unstable, heat labile or susceptible to proteases. Stability of allergen extracts is important for proper diagnosis and therapy of allergic disorders. OBJECTIVE: The present study was undertaken to determine the preservation and stabilization conditions of Imperata cylindrica (Ic) grass pollen extract. METHODS: The Ic extract was kept with 0.1 mepsilon-aminocaproic acid (EACA), 0.75 m sucrose, 5% glycerol, 0.03% human serum albumin (HSA) or 0.4% phenol for different time periods. The extracts were stored for 3, 6 and 12 months each at 4 degrees C, 4 degrees C with daily exposure to room temperature (RT) for 1 h, and RT. The quality of extracts was analysed by SDS-PAGE, Western blot, ELISA, ELISA inhibition and skin test. RESULTS: Extracts kept with EACA and sucrose retained most of the protein bands followed by glycerol as determined by SDS-PAGE and Western blot during all storage periods and conditions in comparison with standard extracts. The extracts kept with HSA, phenol and without preservative (WP) showed protein degradation below 33 kDa after 3 months storage at all conditions. However, a 67-kDa allergen was stable in these extracts. EACA extract required 75 to 120 ng of protein for 50% inhibition in IgE binding under different conditions, whereas standard extract required 70 ng for the same. ELISA also demonstrated high allergenic reactivity of EACA extract. ID test on allergy patients with EACA extract demonstrated same allergenic potency as that of standard extract. CONCLUSION: EACA is the best preservative/stabilizing agent of Ic pollen extract, followed by sucrose and glycerol. Ic extract kept with phenol, HSA and without preservative showed degradation within 3 months. EACA preserved extract is equally potent as that of standard extract up to 1 year's storage. 相似文献
58.
59.
60.
S. C. Mohapatra P. Mohapatra I. J. Singh S. D. Gaur 《European journal of epidemiology》1989,5(1):117-122
The pattern of gastro-intestinal (GIT) and Respiratory tract (RTI) diseases in rural areas of the Varanasi district, U.P. (India) was studied from the outpatient (OPD) attendance between July 1985 to June 1986. Out of a total of new patients, 19.71% had respiratory diseases in contrast to 27.9% with GIT disease. A decreasing trend was observed in attendance rates as age advanced. The difference in age distribution of males and females was statistically significant. The attendance rates for GIT diseases were higher in female (29.16%) than in males (25.16%) whereas in RTI, the rates were higher in males (19.39%) than in females (18.77%). The attendance rate was found to be higher in rainy season (23.59%) followed by summer (14.50%). Diarrhoea (15.44%) and upper (URTI) respiratory tract infection (19.93%) occupied the major recorded episodes. 相似文献