全文获取类型
收费全文 | 931853篇 |
免费 | 66167篇 |
国内免费 | 1342篇 |
专业分类
耳鼻咽喉 | 12957篇 |
儿科学 | 24358篇 |
妇产科学 | 23232篇 |
基础医学 | 132872篇 |
口腔科学 | 28246篇 |
临床医学 | 80525篇 |
内科学 | 183216篇 |
皮肤病学 | 19227篇 |
神经病学 | 72166篇 |
特种医学 | 36797篇 |
外国民族医学 | 79篇 |
外科学 | 152061篇 |
综合类 | 18042篇 |
现状与发展 | 1篇 |
一般理论 | 234篇 |
预防医学 | 61735篇 |
眼科学 | 21307篇 |
药学 | 72520篇 |
3篇 | |
中国医学 | 2162篇 |
肿瘤学 | 57622篇 |
出版年
2018年 | 8959篇 |
2017年 | 7025篇 |
2016年 | 7758篇 |
2015年 | 8856篇 |
2014年 | 11980篇 |
2013年 | 17490篇 |
2012年 | 24074篇 |
2011年 | 25025篇 |
2010年 | 14797篇 |
2009年 | 14261篇 |
2008年 | 24590篇 |
2007年 | 25679篇 |
2006年 | 26470篇 |
2005年 | 25416篇 |
2004年 | 24550篇 |
2003年 | 23595篇 |
2002年 | 23141篇 |
2001年 | 54724篇 |
2000年 | 56541篇 |
1999年 | 46947篇 |
1998年 | 10730篇 |
1997年 | 9464篇 |
1996年 | 9592篇 |
1995年 | 8926篇 |
1994年 | 8278篇 |
1993年 | 7593篇 |
1992年 | 35487篇 |
1991年 | 33911篇 |
1990年 | 32734篇 |
1989年 | 31869篇 |
1988年 | 28991篇 |
1987年 | 28249篇 |
1986年 | 26288篇 |
1985年 | 25144篇 |
1984年 | 17832篇 |
1983年 | 15141篇 |
1982年 | 7795篇 |
1981年 | 6771篇 |
1979年 | 15781篇 |
1978年 | 10598篇 |
1977年 | 9052篇 |
1976年 | 7871篇 |
1975年 | 8628篇 |
1974年 | 10466篇 |
1973年 | 9858篇 |
1972年 | 9357篇 |
1971年 | 8852篇 |
1970年 | 8426篇 |
1969年 | 7923篇 |
1968年 | 7200篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
T. A. Fedotcheva N. L. Shimanovskii A. I. Senderovich N. S. Chermnykh A. V. Semeikin V. M. Rzheznikov L. E. Golubovskaya G. S. Grinenko V. V. Banin P. V. Sergeev 《Pharmaceutical Chemistry Journal》2007,41(7):345-349
The hormonal compound with the highest cytostatic activity against MCF-7 tumor cells (human breast cancer, BC) and the lowest
activity against normal cells (rat skin fibroblasts) was sought among gestagens, androstenes, and antiestrogencytostatics.
It was found that antiestrogencytostatics and androstenes had the highest cytostatic activity against tumor cells whereas
gestagens and antiestrogencytostatics were least active against fibroblasts. Studies of the activity of the hormonal compounds
in combination with doxorubicin on the viability of MCF-7 and rat skin fibroblasts found that all investigated compounds with
the exception of dehydroepiandrosterone (DHEA) intensify the cytostatic activity of doxorubicin against tumor cells, the greatest
effect seen for antiestrogencytostatics. A chemoprotective effect of androstenes on normal cells was noted.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 7, pp. 3–7, July, 2007. 相似文献
994.
995.
K Tanaka Y Miyake S Sasaki Y Ohya S Miyamoto I Matsunaga T Yoshida Y Hirota H Oda 《Magnesium research》2006,19(4):268-275
There have only been a few studies on the role of mineral intake in tooth loss. We investigated the association between mineral intake and the prevalence of tooth loss in Japan. We used the baseline data on 1002 pregnant women who were enrolled in the Osaka Maternal and Child Health Study between November 2001 and March 2003. Tooth loss was defined as the previous extraction of one or more teeth. Nutrient intake was assessed by a validated diet history questionnaire. Prevalence odds ratios and confidence intervals were estimated by applying a multiple logistic regression model. The adjusted odds ratio upon comparison of the highest quartile with the lowest quartile of magnesium intake was 0.64 (95% confidence interval, 0.42-0.99), showing a tendency for an inverse dose-response relationship (p for linear trend = 0.05). There were no associations between the level of consumption of calcium, phosphate, iron, zinc, or copper and tooth loss. The present findings suggest that intake of magnesium is related to reduced prevalence of tooth loss among young Japanese women. 相似文献
996.
997.
Extranodal lymphomas presenting as soft tissue sarcomas to a sarcoma service over a two-year period.
J K O'Neill V Devaraj D A T Silver P Sarsfield C A Stone 《Journal of plastic, reconstructive & aesthetic surgery》2007,60(6):646-654
Non-Hodgkin's lymphoma usually presents with lymphadenopathy at multiple sites but can also involve any part of the musculoskeletal system. Occasionally the presentation is with a soft tissue mass. The presentation of large, superficial lymphomatous masses is similar both clinically and radiologically to that of soft tissue sarcomas. The six cases of lymphoma presenting to the Exeter Sarcoma Service as suspected soft tissue sarcomas, over a two-year period (2002-2004), are presented. We describe the clinical and imaging characteristics of these tumours and their subsequent management. Our cases showed variability in presentation. Only one of the six cases presented with pain and one with tenderness. Four of the cases had no lymphadenopathy and the other two had lymphadenopathy restricted to one nodal basin. Overlying soft tissue swelling occurred in four cases and in distal limb swelling beyond the mass in one case. Radiologically, lymphomas are known to be likely to exhibit confluent lymphadenopathy that is rare in patients with soft tissue sarcoma. Confluent lymphadenopathy was demonstrated in only one case of this series of patients. It is thought that lymphomas infiltrate across anatomical fascial planes more readily than sarcomas and in four of our six cases this feature was present. Clinical history, examination and MRI are insufficient to differentiate between soft tissue sarcoma and lymphoma and the importance of obtaining a pathological diagnosis prior to surgery is clear. It is crucial to differentiate lymphoma from sarcoma in order to avoid unnecessary excisional procedures in lymphoma patients. 相似文献
998.
999.
1000.
Donald B. Penzien PhD ; Frank Andrasik PhD ; Brian M. Freidenberg PhD ; Timothy T. Houle PhD ; Alvin E. Lake III PhD; Gay L. Lipchik PhD ; Kenneth A. Holroyd PhD ; Richard B. Lipton MD ; Douglas C. McCrory MD ; Justin M. Nash PhD ; Robert A. Nicholson PhD ; Scott W. Powers PhD ABPP ; Jeanetta C. Rains PhD ; David A. Wittrock PhD 《Headache》2005,45(S2):S110-S132
Guidelines for design of clinical trials evaluating behavioral headache treatments were developed to facilitate production of quality research evaluating behavioral therapies for management of primary headache disorders. These guidelines were produced by a Workgroup of headache researchers under auspices of the American Headache Society. The guidelines are complementary to and modeled after guidelines for pharmacological trials published by the International Headache Society, but they address methodologic considerations unique to behavioral and other nonpharmacological treatments. Explicit guidelines for evaluating behavioral headache therapies are needed as the optimal methodology for behavioral (and other nonpharmacologic) trials necessarily differs from the preferred methodology for drug trials. In addition, trials comparing and integrating drug and behavioral therapies present methodological challenges not addressed by guidelines for pharmacologic research. These guidelines address patient selection, trial design for behavioral treatments and for comparisons across multiple treatment modalities (eg, behavioral vs pharmacologic), evaluation of results, and research ethics. Although developed specifically for behavioral therapies, the guidelines may apply to the design of clinical trials evaluating many forms of nonpharmacologic therapies for headache. 相似文献