全文获取类型
收费全文 | 36745篇 |
免费 | 2501篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 393篇 |
儿科学 | 985篇 |
妇产科学 | 877篇 |
基础医学 | 5114篇 |
口腔科学 | 938篇 |
临床医学 | 3690篇 |
内科学 | 7426篇 |
皮肤病学 | 683篇 |
神经病学 | 3342篇 |
特种医学 | 1544篇 |
外国民族医学 | 5篇 |
外科学 | 5123篇 |
综合类 | 182篇 |
一般理论 | 22篇 |
预防医学 | 2963篇 |
眼科学 | 705篇 |
药学 | 2660篇 |
中国医学 | 60篇 |
肿瘤学 | 2575篇 |
出版年
2023年 | 395篇 |
2022年 | 136篇 |
2021年 | 469篇 |
2020年 | 530篇 |
2019年 | 604篇 |
2018年 | 1197篇 |
2017年 | 1095篇 |
2016年 | 1109篇 |
2015年 | 905篇 |
2014年 | 1000篇 |
2013年 | 1794篇 |
2012年 | 2563篇 |
2011年 | 2658篇 |
2010年 | 1212篇 |
2009年 | 740篇 |
2008年 | 2225篇 |
2007年 | 2267篇 |
2006年 | 2118篇 |
2005年 | 1964篇 |
2004年 | 1809篇 |
2003年 | 1693篇 |
2002年 | 1720篇 |
2001年 | 1126篇 |
2000年 | 1301篇 |
1999年 | 806篇 |
1998年 | 224篇 |
1997年 | 180篇 |
1996年 | 157篇 |
1995年 | 155篇 |
1994年 | 149篇 |
1993年 | 136篇 |
1992年 | 247篇 |
1991年 | 243篇 |
1990年 | 233篇 |
1989年 | 233篇 |
1988年 | 249篇 |
1987年 | 240篇 |
1986年 | 228篇 |
1985年 | 283篇 |
1984年 | 242篇 |
1983年 | 203篇 |
1982年 | 156篇 |
1981年 | 128篇 |
1980年 | 109篇 |
1979年 | 209篇 |
1978年 | 125篇 |
1977年 | 129篇 |
1975年 | 86篇 |
1974年 | 88篇 |
1973年 | 97篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
F. G. Pajonk H. H. Bartels K. A. S. Grünberg Hp. Moecke 《Notfall & Rettungsmedizin》2002,5(2):110-115
Pre-clinical psychiatric emergency situations (PES) have been identified to be the third major reason for emergency physician (EP) calls with a frequency of approximately 10%. Until now, there are no investigations about regional differences between urban and rural regions in frequencies, diagnoses, or treatment necessities of PES. A retrospective analysis of all anonymised EP protocols of one year in a metropolitan (Hamburg) and a rural region (Schaumburg County) was performed with the same methodological approach. In both regions, the frequency of PES was revealed to be near 10%. Gender and age of psychiatric patients as well as reasons for calls were comparable. In Schaumburg County, much less disturbances due to illegal drugs were observed. However, more patients had to be treated because of suicide attempts and alcoholism. All in all, disturbances seemed less life-threatening than in the metropolitan region. In conclusion, frequency and kind of PES do not differ substantially between rural and urban regions. Considering the prevalence of PES, the particularities in diagnosis and treatment and the dissipation of institutionalised psychiatric care mainly in rural regions, more training in psychiatric subjects is needed. 相似文献
32.
33.
Martin Døssing Steffen Groth Jørgen Vestbo Ole Lyngenbo 《International archives of occupational and environmental health》1990,62(3):209-212
Summary Among 701 Copenhagen plumbers we examined the lung function of 23 never smokers, who had removed asbestos insulation and intermittently been exposed to high levels of asbestos for about 25 years without being exposed to welding fume. The plumbers had significantly lower TLC, MEF25, MEF50, closing volume and closing capacity in comparison to 23 never smoking electricians without asbestos exposure. There was no reduction in TLCO. Pulmonary clearance of aerosolized 99mTc-DTPA was normal indicating that the asbestos had not induced increases in pulmonary epithelial permeability. However, in 11 of the 23 plumbers the 99m-Tc-DTPA ventilation scintigrams had a slightly irregular and spotty appearance, which together with the results of the lung function tests are suggestive of small airways' dysfunction. None of the subjects had symptoms or clinical signs of lung disease. 相似文献
34.
After p.o. administration of 5-piperidino-7-[N-pentyl-N-(beta- hydroxyethyl)]amino-s-triazolo[1,5-a]pyrimidine (1; AR 12463) more than 15 metabolites were isolated from urine and feces of male Wistar rats. Only small amounts of unchanged 1 were observed. The structure of 12 metabolites was elucidated or proposed on the basis of UV-, 13C NMR- and mass spectra. Main metabolites are 5-piperidin-4'-olyl-7-[N-pentyl-N-(beta- hydroxyethyl)]amino-s-triazolo[1,5-a]pyrimidine and 5-piperidin-4'-olyl-7-[N-pent-4-olyl-N-(beta-hydroxyet hyl)]amino-s- triazolo[1,5-a]pyrimidine. The other metabolites are mainly hydroxy- or ketopentyl derivatives and piperidinoles or piperidinones, respectively. Conjugates of most of the metabolites were identified, but the ratio phase-I/II metabolites was about 3:1. In contrast to trapidil, 5-methyl-7-diethylamino-s- triazolo[1,5-a]pyrimidine, no hydroxy derivatives of the bicyclic system were observed. The major part of unchanged 1 and metabolites is excreted via kidneys. 相似文献
35.
International comparisons show that populations having a high consumption of fish experience low incidence of breast cancer. We compared death rates from breast cancer among socioeconomic groups in a prospective study of 533,276 Norwegian women aged 35–54 years who were followed from 1970 through 1985. Compared with the reference group (wives of unskilled workers) the fishermen's wives had a decreased risk of breast cancer with a relative risk (RR) of 0.67 (95% confidence interval [CI]=0.47–0.94) adjusted for age and the number of children. Among fishermen's wives who were parous, adjustment for age at first birth gave an RR of 0.62 (CI=0.43–0.91). This study supports the hypothesis that certain aspects of diet, i. e., fish consumption, may be associated with lower breast-cancer mortality.Drs Lund and Bønaa are with the Institute of Community Medicine, University of Tromsø, Tromsø, Norway. Address correspondence to Dr Lund, Institute of Community Medicine, University of Tromsø, N-9037 Tromsø, Norway. 相似文献
36.
Striae distensae are an appreciable cosmetic problem for many pregnant women. Preventive application of a water/oil massage cream was tested in a group of 24 gravidae (control group: 26 patients). In the untreated control group striae distensae were observed in two-thirds of the patients, whereas the prophylactically-treated gravidae showed development of striae in only one third of the group given the test preparation. Better results were obtained in women with a favourable constitutional predisposition than in patients with a tendency to overweight. The massage cream was well tolerated by all gravidae. 相似文献
37.
Jens Toft Birger Hesse Alan Rabøl Steen Carstensen Samir Ali 《European journal of nuclear medicine and molecular imaging》1997,24(4):409-414
Reference data files support the evaluation of myocardial perfusion single-photon emission tomography (SPET). The aim of this study was to create a large reference data base for technetium-99m sestamibi SPET, age and gender matched to the general patient population. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a likelihood of coronary artery disease of less than 5% underwent rest and maximal exercise99mTc-sestamibi SPET with a 2-day protocol and 180° elliptical rotation. The normalized activity values of99mTc-sestamibi in the inferior wall differed significantly between men and women. Age variations were found for men in the anterior wall. Normalized activity values in all four walls were strikingly similar during rest and stress. Our results suggest that the use of reference files in99mTc-sestamibi SPET requires a gender- and, for males, possibly an age-matched reference population. Different reference files at rest and during stress might not be necessary. 相似文献
38.
Nitrosamine excretion in patients with continent ileal reservoirs for urinary diversion. 总被引:1,自引:0,他引:1
Adenocarcinomas are a recognized complication following ureterosigmoidostomy for which the endogenous formation of N-nitroso compounds may be a risk factor. As an alternative means of urinary diversion, the continent ileal reservoir has recently been developed. Microbiological and chemical investigations on the urine of patients with an ileal reservoir showed the presence of bacteria, nitrate, nitrite and N-nitrosamines formed endogenously in the ileal pouch. The role of nitrosamines in carcinogenesis in these patients as a late stage complication resulting from the use of a continent ileal reservoir is discussed. 相似文献
39.
Assessorin Dorit Gräbsch 《MedR Medizinrecht》2007,25(8):VI-VIII
Ohne Zusammenfassung 相似文献
40.
The incidence of multiple sclerosis (MS) was studied in the county of Hordaland, western Norway. A significant increase in incidence in the period 1958-1987, a decline followed by a gradual increase in mean age at onset, geographic differences in time trends and a biphasic pattern revealed by a birth cohort analysis support the theory of real time-space fluctuations in the incidence of MS over time. 相似文献