全文获取类型
收费全文 | 512979篇 |
免费 | 33973篇 |
国内免费 | 612篇 |
专业分类
耳鼻咽喉 | 6892篇 |
儿科学 | 16833篇 |
妇产科学 | 13531篇 |
基础医学 | 84989篇 |
口腔科学 | 14470篇 |
临床医学 | 44292篇 |
内科学 | 93469篇 |
皮肤病学 | 12154篇 |
神经病学 | 36156篇 |
特种医学 | 18448篇 |
外国民族医学 | 63篇 |
外科学 | 77028篇 |
综合类 | 8464篇 |
一般理论 | 118篇 |
预防医学 | 38928篇 |
眼科学 | 12125篇 |
药学 | 40509篇 |
中国医学 | 1006篇 |
肿瘤学 | 28089篇 |
出版年
2018年 | 4923篇 |
2015年 | 4508篇 |
2014年 | 6059篇 |
2013年 | 9544篇 |
2012年 | 12868篇 |
2011年 | 14270篇 |
2010年 | 8302篇 |
2009年 | 7776篇 |
2008年 | 13693篇 |
2007年 | 14700篇 |
2006年 | 14940篇 |
2005年 | 14362篇 |
2004年 | 14049篇 |
2003年 | 13390篇 |
2002年 | 13268篇 |
2001年 | 24069篇 |
2000年 | 25079篇 |
1999年 | 20555篇 |
1998年 | 5426篇 |
1997年 | 4705篇 |
1996年 | 5041篇 |
1995年 | 4626篇 |
1994年 | 4318篇 |
1993年 | 4135篇 |
1992年 | 15725篇 |
1991年 | 16309篇 |
1990年 | 16422篇 |
1989年 | 15796篇 |
1988年 | 14575篇 |
1987年 | 14419篇 |
1986年 | 13597篇 |
1985年 | 12975篇 |
1984年 | 9627篇 |
1983年 | 8247篇 |
1982年 | 4559篇 |
1981年 | 4229篇 |
1979年 | 9418篇 |
1978年 | 6855篇 |
1977年 | 5772篇 |
1976年 | 5602篇 |
1975年 | 6396篇 |
1974年 | 7634篇 |
1973年 | 7130篇 |
1972年 | 6960篇 |
1971年 | 6685篇 |
1970年 | 6172篇 |
1969年 | 5888篇 |
1968年 | 5559篇 |
1967年 | 5012篇 |
1966年 | 4450篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
931.
J G Brody R Rudel N I Maxwell S R Swedis 《Public health reports (Washington, D.C. : 1974)》1996,111(6):494-507
Geographic patterns and time trends for breast cancer suggest there are preventable causes that may include environmental factors. This article describes the development of new methods used in the Cape Cod Breast Cancer and Environment Study to investigate whether synthetic chemicals in the environment contribute to breast cancer risk. 相似文献
932.
B F Trump T W Jones K A Elliget M W Smith P C Phelps A Maki I K Berezesky 《Renal failure》1990,12(3):183-191
Cellular toxicity and cellular carcinogenesis are closely linked. In the kidney, this relationship has been emphasized by the recent discovery of a number of putatively non-mutagenic chemicals that result in acute and chronic toxicity and ultimately in carcinogenesis, especially in the male rat. Many, but not all such compounds, result in renal PTE phagolysosomal overload. At the same time, known metabolites of other carcinogens, e.g., HCBD and FBPA, result in acute renal injury and/or necrosis, followed by chronic tubular disease, interstitial nephritis, and ultimately carcinogenesis. A series of cell mechanisms have been suggested that lead from acute cell injury to altered control of cell division. These mechanisms appear to involve ion deregulation, (especially [Ca2+]i) resulting from a variety of continued injuries, (e.g., oxidative stress from inflammatory cells) and ultimately leading to altered gene expression. 相似文献
933.
Acetylcholinesterase activity and pseudocholinesterase activity were examined in plasma and in striated muscles (whole heart and diaphragm muscles) of diabetic KK-CAy mice. Both activities of acetylcholinesterase in heart muscle and pseudocholinesterase in plasma were significantly increased in diabetic KK-CAy mice compared to pre-diabetic KK-CAy mice. Both acetylcholinesterase and pseudocholinesterase activities in skeletal muscle were not changed by the diabetic state. The increases in activity of plasma pseudocholinesterase was significantly correlated to the increase in blood glucose level in alloxan-, streptozotocin (STZ)-diabetic ddY mice and diabetic KK-CAy mice. The increase was not correlated to the body weight in non-diabetic female-KK-CAy mice. Furthermore, the activity of heart acetylcholinesterase was significantly correlated with the activity of plasma pseudocholinesterase (r = 0.79, P less than 0.01). The activities of acetylcholinesterases in heart muscles from STZ- and alloxan-diabetic ddY mice also tended to increase. The hypersensitivity of the pulse rate to a low dose (1 mg/kg) of acetylcholine was correlated to the activity of plasma pseudocholinesterase (r = -0.51, P less than 0.05). These results demonstrate that the activities of plasma pseudocholinesterase were increased by the diabetic state being associated with the increasing alteration of cardiac sensitivity to acetylcholine in the whole body. 相似文献
934.
935.
936.
937.
938.
939.
940.
Prognostic significance of serum cholesterol in nursing home men 总被引:2,自引:0,他引:2
D Rudman D E Mattson H S Nagraj A G Feller D L Jackson N Caindec I W Rudman 《JPEN. Journal of parenteral and enteral nutrition》1988,12(2):155-158
Serum cholesterol was measured in 129 men (average age 70.6; range 41-96) of a Veterans Administration Nursing Home, and was correlated with other items in an extensive clinical data base. Serum cholesterol was less than 150 mg/dl in 13% of the subjects, and was less than 160 mg/dl in 18%. Cholesterol greater than 280 mg/dl occurred in 8%. Serum cholesterol varied directly (p less than 0.02) with: body weight, serum albumin, serum total protein, serum sodium, ability to walk, and ability to feed oneself; and indirectly (p less than 0.02) with death rate, degree of functional dependence, and serum SGOT and LDH. Nursing home men with cholesterol less than 150 mg/dl had a death rate of 63% during the 14 months after the cholesterol analysis, compared to a death rate of 9% in men with cholesterol greater than 150 mg/dl (p less than 0.05). Death rate during the year after the analysis was 52% if cholesterol was below 160 mg/dl, compared to 7% if it was above this threshold (p less than 0.05). 相似文献