全文获取类型
收费全文 | 3267992篇 |
免费 | 260138篇 |
国内免费 | 7029篇 |
专业分类
耳鼻咽喉 | 46642篇 |
儿科学 | 102748篇 |
妇产科学 | 89808篇 |
基础医学 | 458636篇 |
口腔科学 | 92996篇 |
临床医学 | 298885篇 |
内科学 | 638589篇 |
皮肤病学 | 70465篇 |
神经病学 | 274823篇 |
特种医学 | 129127篇 |
外国民族医学 | 1186篇 |
外科学 | 488743篇 |
综合类 | 78643篇 |
现状与发展 | 5篇 |
一般理论 | 1342篇 |
预防医学 | 264511篇 |
眼科学 | 77549篇 |
药学 | 239781篇 |
5篇 | |
中国医学 | 6962篇 |
肿瘤学 | 173713篇 |
出版年
2018年 | 35623篇 |
2017年 | 27353篇 |
2016年 | 30749篇 |
2015年 | 34971篇 |
2014年 | 49928篇 |
2013年 | 74888篇 |
2012年 | 101132篇 |
2011年 | 106659篇 |
2010年 | 63021篇 |
2009年 | 60002篇 |
2008年 | 99401篇 |
2007年 | 105358篇 |
2006年 | 106116篇 |
2005年 | 103136篇 |
2004年 | 98785篇 |
2003年 | 94875篇 |
2002年 | 92768篇 |
2001年 | 151184篇 |
2000年 | 155879篇 |
1999年 | 131296篇 |
1998年 | 38607篇 |
1997年 | 34967篇 |
1996年 | 34608篇 |
1995年 | 33178篇 |
1994年 | 30849篇 |
1993年 | 28923篇 |
1992年 | 103746篇 |
1991年 | 99771篇 |
1990年 | 96079篇 |
1989年 | 92381篇 |
1988年 | 85689篇 |
1987年 | 84295篇 |
1986年 | 79456篇 |
1985年 | 75901篇 |
1984年 | 57962篇 |
1983年 | 49371篇 |
1982年 | 30283篇 |
1981年 | 26958篇 |
1979年 | 53619篇 |
1978年 | 37856篇 |
1977年 | 31740篇 |
1976年 | 29824篇 |
1975年 | 31071篇 |
1974年 | 38217篇 |
1973年 | 36530篇 |
1972年 | 34261篇 |
1971年 | 31480篇 |
1970年 | 29797篇 |
1969年 | 27726篇 |
1968年 | 25676篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Predicting failure in polytetrafluoroethylene vascular access grafts for hemodialysis: a pilot study
C R Shackleton D C Taylor A R Buckley V A Rowley P L Cooperberg P D Fry 《Canadian journal of surgery》1987,30(6):442-444
In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk. 相似文献
993.
The records of 29 consecutive patients treated by a pure, open, anterior acromioplasty were reviewed retrospectively. Excluded from consideration were patients with the following pathologic diagnoses or histories: (1) previously attempted acromioplasty on the same shoulder; (2) intraoperatively confirmed rotator cuff tear; (3) any surgically treatable biceps tendon or acromioclavicular abnormality; (4) lost to follow-up study. Three different techniques were employed to perform the acromioplasties. The first technique required partial deltoid origin detachment with an osteotome. The second technique spared the deltoid origin, while again using an osteotome to perform the acromioplasty. The third technique also spared the deltoid origin but used a high-speed burr to perform the acromioplasty. Evaluated in terms of patient satisfaction, residual pain, length of convalescence, suboptimal results, and complications, the first technique proved to be the least effective. The second technique produced early, excellent results. The third technique, in which a burr was employed through an intact deltoid origin, was most effective; technically, the method was also relatively simple and reliable. 相似文献
994.
Several reports in the literature suggest a relationship between lead intoxication and thermoregulatory capacity. To investigate the effects of lead on the control of body temperature, mice of the BALB/c strain were injected intraperitoneally with lead acetate (0 to 100 mg/kg) while colonic temperature was measured 30, 60, and 90 min post-injection at ambient temperatures (Ta) of 20 and 30 degrees C. Lead acetate caused a transient hypothermia, an effect which was augmented at cooler Ta's. In a second experiment, mice were injected with 100 mg/kg lead acetate and placed in a longitudinal temperature gradient to measure their preferred Ta. Lead acetate significantly reduced the preferred Ta during the first 30 min post-injection which augmented the lead-induced hypothermia. In a third experiment it was found that lead acetate-induced lethality was potentiated with increasing Ta. Hence, the hypothermic response to acute lead acetate treatment may be beneficial to survival. 相似文献
995.
S. MD. Iqbal A. K. Garg C. M. Kalaiah 《Indian journal of otolaryngology and head and neck surgery》1987,39(1):38-39
A case of Goldenhar’s Syndrome in a 10 year old girl is reported. The unusual features are the absence of epibulbar dermoid which is one of the major hallmarks of the Syndrome and the presence of an associated Cyanotic Heart disease. 相似文献
996.
J L Schrader 《The American journal of psychiatry》1987,144(1):107-109
The Alaska mental health program is endowed with a 1-million-acre trust fund. A coalition of groups that make up the mental health constituency of the state united in a lawsuit to establish the trust. The history of this legacy, the struggle to realize its benefits, its current status, and some of its psychopolitical significance are discussed. 相似文献
997.
998.
999.
Outcomes were compared between consecutive patients who had received either total lymphoid irradiation (TLI) or immunosuppressant treatment for intractable rheumatoid arthritis (RA). There were 33 TLI and 32 immunosuppressive recipients; all patients had failed standard therapy. Average followup from the start of therapy was 2.7 years for TLI and 5.9 years for immunosuppressive recipients. Final disability levels were the same in both groups; mortality was equal in both groups as well. There were more hospitalizations for infections in the TLI group and the infecting organisms tended to be staphylococcus or gram negative organisms. Apart from infections, there were more adverse effects reported in the immunosuppressive therapy group. 相似文献
1000.
C M Mond D B Walters R S Stricoff E M Prescott A T Prokopetz 《American Industrial Hygiene Association journal》1987,48(10):823-829
A human factors engineering analysis of a chemical containment laboratory was performed to develop appropriate standards for future laboratory design. In order to perform this evaluation, a state-of-the-art facility was studied in depth. Measurements and observations were made of key operating areas. In addition, technicians were observed and interviewed as they performed various tasks. Compiled data were compared to existing ergonomic standards. The occupational implications of instituting ergonomically developed laboratory design standards are as follows: increased worker health, safety and productivity, improved work quality and reduced stress. 相似文献