全文获取类型
收费全文 | 272114篇 |
免费 | 11537篇 |
国内免费 | 5798篇 |
专业分类
耳鼻咽喉 | 3354篇 |
儿科学 | 8699篇 |
妇产科学 | 6479篇 |
基础医学 | 31750篇 |
口腔科学 | 7541篇 |
临床医学 | 25577篇 |
内科学 | 43644篇 |
皮肤病学 | 5506篇 |
神经病学 | 14621篇 |
特种医学 | 13879篇 |
外国民族医学 | 123篇 |
外科学 | 37061篇 |
综合类 | 18807篇 |
现状与发展 | 19篇 |
一般理论 | 13篇 |
预防医学 | 23362篇 |
眼科学 | 5888篇 |
药学 | 22118篇 |
91篇 | |
中国医学 | 5564篇 |
肿瘤学 | 15353篇 |
出版年
2023年 | 1083篇 |
2022年 | 2540篇 |
2021年 | 3487篇 |
2020年 | 3057篇 |
2019年 | 2222篇 |
2018年 | 5782篇 |
2017年 | 6210篇 |
2016年 | 5165篇 |
2015年 | 8319篇 |
2014年 | 8946篇 |
2013年 | 8209篇 |
2012年 | 16716篇 |
2011年 | 12126篇 |
2010年 | 8120篇 |
2009年 | 9050篇 |
2008年 | 7392篇 |
2007年 | 7831篇 |
2006年 | 7933篇 |
2005年 | 15188篇 |
2004年 | 15513篇 |
2003年 | 10772篇 |
2002年 | 5454篇 |
2001年 | 5912篇 |
2000年 | 2973篇 |
1999年 | 6782篇 |
1992年 | 6998篇 |
1991年 | 7194篇 |
1990年 | 7410篇 |
1989年 | 7010篇 |
1988年 | 6517篇 |
1987年 | 6278篇 |
1986年 | 5988篇 |
1985年 | 5263篇 |
1984年 | 3603篇 |
1983年 | 2917篇 |
1979年 | 3838篇 |
1978年 | 2367篇 |
1977年 | 1784篇 |
1976年 | 1562篇 |
1975年 | 2481篇 |
1974年 | 3111篇 |
1973年 | 2750篇 |
1972年 | 2760篇 |
1971年 | 2744篇 |
1970年 | 2560篇 |
1969年 | 2466篇 |
1968年 | 2238篇 |
1967年 | 2165篇 |
1966年 | 1899篇 |
1965年 | 1131篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A cohort study of workers at a smeltery in northern Sweden showed an excess mortality, mostly due to deaths in cancer (especially in the respiratory organs) and circulatory diseases. Further follow-up of the cohort showed a decreasing trend in lung cancer incidence and mortality. The cohort studied has now been expanded and comprises 6,334 blue-collar workers first employed 1928-1979. They were followed in the cancer register up to 1987-01-01 and in the cause-of-death register up to 1988-01-01. The decreasing trend in lung cancer incidence and mortality continued but there was still an elevated lung cancer incidence among the workers when compared with Swedish males. The cumulative occurrence of lung cancer since time of first employment was analyzed by different employment cohorts and a higher occurrence of lung cancer was found among those earlier employed. 相似文献
992.
Dose dependence of zinc and manganese absorption in man. 总被引:1,自引:0,他引:1
B Sandstr?m 《The Proceedings of the Nutrition Society》1992,51(2):211-218
993.
The in-vitro oestradiol (E2) and progesterone (P) production by corpora lutea (CL) obtained at sterilization from 30 untreated women and 43 women treated with norethisterone (NET) 300 micrograms daily was measured. The CL were obtained at different stages of the luteal phase in the untreated women [luteinizing hormone (LH) 0 to +3, n = 7; LH +4 to +7, n = 7; LH +8 to +11, n = 9; LH +12 to menses, n = 7] and on days LH +8 to +11 or cycle days 22 to 26 in the NET-treated women. In the treated women, four types of ovarian reaction were identified. Four women showed ovarian reaction Type A (completely inhibited ovarian activity), 14 women Type B (marked follicular activity, but no luteal function), 12 women Type C (normal follicular activity, followed by insufficient luteal function) and 13 women Type D (apparently normal follicular and luteal activity). The CL were incubated in Eagle's medium with and without stimulation by human chorionic gonadotrophin (HCG) for 2 and 4 h. In the untreated women, P and E2 production increased significantly with both incubation time and stimulation by HCG throughout the luteal phase, except in the late luteal phase (LH +12 to menses) where P increased (P less than 0.01) only after 4 h stimulation by HCG. The maximal production of P was found after 4 h incubation with HCG stimulation of CL tissue in the early-mid luteal phase (LH +4 to +7).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
994.
995.
Antibacterial therapy of anaerobic infections usually involves chemotherapy. The basis of therapy is assessment of the minimal inhibitory concentration (MIC) of antibiotic or chemotherapeutic agents needed to eliminate the suspected causal agents of infection. The authors assessed MIC of 9 selected antibiotics and chemotherapeutic agents (metronidazole, chloramphenicol, clindamycin, azlocillin, mezlocillin, cephoxitin, oxytetracycline, lincomycin, erythromycin) by the dilution method in blood agar in 157 strains of the most important types of the genus Bacteroides which were isolated in 1985-1989 from different clinical materials in Bratislava and in Halle (GDR). All tested strains were sensitive to metronidazole and chloramphenicol. Resistance to clindamycin was very rare. Strains resistant to azlocillin, mezlocillin and cephotoxin were more frequent. A high resistance to lincomycin, oxytetracycline and erythromycin was found. Difference in sensitivity of strains from the CSSR and GDR were slight. Similarly results of the present work differed little from those of previous work. 相似文献
996.
Jan Paul Ouwens Wim van der Bij Thomas W van der Mark Albert Geertsma Do A Piers Wim J de Boer Gerard H Ko?ter 《The Journal of heart and lung transplantation》2004,23(1):115-121
BACKGROUND: A decrease in forced expiratory volume in 1 second (FEV(1)) as a diagnostic criterion for bronchiolitis obliterans syndrome (BOS) after single lung transplantation may be influenced significantly by the presence of the native lung. To quantify and to discriminate between the relative contribution of graft and native lung to the FEV(1), we retrospectively investigated the diagnostic value of combined FEV(1) measurements and ventilation scintigraphy in pulmonary dysfunction after single lung transplantation in 11 recipients with pulmonary vascular disease, 3 with obstructive lung disease, and 3 with restrictive lung disease. METHODS: We assessed function of the native lung and the graft, and subsequently calculated an adjusted grading of BOS by correcting routine FEV(1) measurements using linear interpolation of bi-annual lung ventilation scans. RESULTS: The contribution of the native lung to the total FEV(1) was slight (median, 9%) in recipients with obstructive disease compared with recipients with vascular (38%) or restrictive lung diseases (27%). Adjusted BOS grading was not useful in patients with obstructive disease. In the other patient groups, the onset of adjusted BOS Grade 1 and standard BOS Grade 1 was at a median of 220 days (range, 127-1146 days) and 836 days (184-3065 days), respectively. CONCLUSION: Ventilation scintigraphy is a useful adjunct in the (early) diagnosis of BOS in recipients of single lung transplants who have vascular and restrictive lung diseases. 相似文献
997.
998.
Sympathetic skin response in scleroderma. 总被引:1,自引:0,他引:1
M Raszewa I Hausmanowa-Petrusewicz M B?aszczyk S Jab?ońska 《Electromyography and clinical neurophysiology》1991,31(8):467-472
Examination of the sympathetic skin response (SSR) was performed in 32 patients with systemic sclerosis, morphea and mixed connective tissue disease displaying scleroderma-like features. The control group consisted of 26 healthy subjects and 12 patients with other skin diseases and asymmetrical cutaneous changes. Right and left median and tibial nerves were stimulated successively and the responses were recorded from the palms and soles simultaneously. SSR abnormalities (delayed latency, decrease and/or asymmetry of amplitude, absent response) were observed in 68.8% of the patients, most frequently in linear scleroderma. An amplitude asymmetry of the responses from upper extremities was the most characteristic pattern of abnormalities. There was no correlation between the SSR and the localization, degree and character (inclurated oedema, atrophy, sclerosis) of skin changes, the duration of the disease, symptoms of the disorder of the autonomic nervous system symptoms (vasomotor and/or sudomotor) and the changes in capillaroscopy. All patients with slow motor conduction and sensor conduction velocities (MCV and SCV) had lower SSR amplitude and the patients with prolonged skin sensory chronaxy had more often delayed latency. The results revealed presence of disturbances of the autonomic nervous system in all varieties of scleroderma, both systemic and localized forms, even without any other signs of autonomic dysfunction. 相似文献
999.
R C de Oliveira A Gon?alves 《Revista do Instituto de Medicina Tropical de S?o Paulo》1991,33(3):233-239
In Brazil, Public Health specialization courses with the characteristics presently adopted by the National School of Public Health, i.e., short duration and great amplitude, are relatively recent, having started approximately fifteen years ago. In Brasília, nine such courses have been already completed, having, six of them, directive and/or teaching involvement by the authors. Results on a final assessment of one the courses are herewith presented in order to introduce our experience as a contribution to future analogous initiatives. The assessment was applied to a random sample of students, teachers and coordinators, with the objective of identifying positive and negative appreciations about methodological, operational, administrative and institutional aspects. Answers were quite variable, with the highest frequencies scored to field work and to the apprehension on admitting graduates to the Health System. Such aspects deserve final differentiated discussion. 相似文献
1000.