全文获取类型
收费全文 | 212532篇 |
免费 | 38607篇 |
国内免费 | 2488篇 |
专业分类
耳鼻咽喉 | 5637篇 |
儿科学 | 7299篇 |
妇产科学 | 3832篇 |
基础医学 | 11773篇 |
口腔科学 | 2919篇 |
临床医学 | 34956篇 |
内科学 | 59093篇 |
皮肤病学 | 8372篇 |
神经病学 | 20181篇 |
特种医学 | 8481篇 |
外国民族医学 | 1篇 |
外科学 | 48665篇 |
综合类 | 1589篇 |
现状与发展 | 72篇 |
一般理论 | 75篇 |
预防医学 | 14805篇 |
眼科学 | 4432篇 |
药学 | 6017篇 |
1篇 | |
中国医学 | 111篇 |
肿瘤学 | 15316篇 |
出版年
2023年 | 5059篇 |
2022年 | 1677篇 |
2021年 | 4376篇 |
2020年 | 6768篇 |
2019年 | 3533篇 |
2018年 | 8836篇 |
2017年 | 8396篇 |
2016年 | 9485篇 |
2015年 | 9687篇 |
2014年 | 17197篇 |
2013年 | 18053篇 |
2012年 | 9193篇 |
2011年 | 9186篇 |
2010年 | 12335篇 |
2009年 | 15970篇 |
2008年 | 8979篇 |
2007年 | 7349篇 |
2006年 | 9587篇 |
2005年 | 6797篇 |
2004年 | 5789篇 |
2003年 | 4523篇 |
2002年 | 4479篇 |
2001年 | 5393篇 |
2000年 | 4488篇 |
1999年 | 4704篇 |
1998年 | 4328篇 |
1997年 | 4009篇 |
1996年 | 3897篇 |
1995年 | 3718篇 |
1994年 | 2389篇 |
1993年 | 2070篇 |
1992年 | 2593篇 |
1991年 | 2543篇 |
1990年 | 2129篇 |
1989年 | 2214篇 |
1988年 | 1988篇 |
1987年 | 1818篇 |
1986年 | 1865篇 |
1985年 | 1617篇 |
1984年 | 1319篇 |
1983年 | 1153篇 |
1982年 | 938篇 |
1981年 | 751篇 |
1980年 | 699篇 |
1979年 | 891篇 |
1978年 | 812篇 |
1977年 | 764篇 |
1974年 | 656篇 |
1973年 | 628篇 |
1972年 | 687篇 |
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
991.
992.
Claude Clément MD Roberto Ruiz MD Bogdan Costa-Foru MD Hubert Nicaise MD 《Annals of vascular surgery》1990,4(3):305-308
Extrinsic compression of the renal artery due to a fibromuscular band originating from the diaphragm was encountered in a 26-year-old patient who had systemic hypertension associated with stenosis and kinking of one of her renal arteries. After surgical decompression, the renal artery assumed a normal expansion with disappearance of hypertension. Six other cases of extrinsic compression of the renal artery have been found in the literature. Surgical treatment is mandatory in all cases because the mechanism that causes the lesion makes percutaneous transluminal angioplasty illusory. 相似文献
993.
P J O'Brien E Ling H M Williams S Brotherton T Salerno J H Lumsden C D Ianuzzo 《The Canadian journal of cardiology》1988,4(5):243-250
This study was undertaken to test the hypothesis that a compensatory response of the heart to a chronic and continuous, metabolic and heart rate overload was an increase in the calcium sequestering activity of the myocardial sarcoplasmic reticulum. Calcium sequestering activity was estimated by determination of the calcium-dependent ATPase (Ca2+-ATPase) activity of isolated microsomes. Chronic rate overload was modelled by comparing: dysthyroid and control rats; control swine and swine with implanted cardiac pacemakers set at 180 beats/min; and different species of mammals with widely different heart rates. The myocardial sarcoplasmic reticulum Ca2+-ATPase pump activity was significantly increased by 39% for hyperthyroid rats compared to control rats and by 87% for control rats compared to thyroidectomized rats; by 63% for paced swine compared to control swine; and by 43% for rats compared to guinea pigs, by 140% for guinea pigs compared to dogs and by 120% for dogs compared to cows. These data indicate that calcium sequestering activity of myocardial sarcoplasmic reticulum increases in equivalent proportion to the chronotropic demand and that heart rate is a hemodynamic correlate of the sarcoplasmic reticulum Ca2+-ATPase activity. 相似文献
994.
A sensitive assay for human plasma BzAO, involving the conversion of 14C-benzylamine to 14C-benzaldehyde, was developed. MPTP and several of its analogues were found to be competitive inhibitors of the enzyme. Ki values for the MPTP analogues in the presence of human plasma BzAO were determined. The analogues had a different rank order of inhibition of human plasma BzAO compared with the rank order of inhibition of bovine plasma BzAO found previously. MPTP and 1-methyl-4-(2-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH3-MPTP), which are potent nigrostriatal toxins, were weak inhibitors of human plasma BzAO. 相似文献
995.
Yasuo Miyoshi Seigoh Mizumoto MD Hideo Akashi Eiji Kurokawa Hideyuki Mishima Keisuke Iihara Kohji Takami Masayuki Ohue Yukitoshi Aoki 《Surgery today》1990,20(6):711-714
A rare case of jejunal carcinoma coexisting with adenoma, situated 120 cm distal to the ligament of Treitz in a 53 year old
male, is reported herein. We also review cases of adenoma and carcinoma in the jejunum and ileum from the Japanese literature,
and discuss the histogenesis of carcinoma of the jejunum and ileum. 相似文献
996.
997.
Multiple myeloma: infectious complications 总被引:1,自引:0,他引:1
We review a ten-year experience in treating 60 patients with multiple myeloma. Infectious episodes occurred in 33 patients. Urinary tract infections caused by gram-negative organisms were the most frequent infections, and most of these were the result of catheterization. Pneumonia due to Streptococcus pneumoniae was encountered infrequently. This series confirms the emergence of gram-negative bacilli as the predominant pathogens in patients with multiple myeloma, and emphasizes the risk of instrumentation in these patients. 相似文献
998.
John D. Hughes MD Changyi Chen MD Samer G. Mattar MB ChB Ayten Someren MD Beverly Noe BS Carolyn R. Suwyn BS Alan B. Lumsden MD 《Annals of vascular surgery》1996,10(2):123-130
Hypothermia and preservative perfusates have been used to decrease ischemic renal injury. This study was performed to identify the preservative function of perfusates independent of the effects of hypothermia. Rats underwent 45 minutes of renal ischemia. Rectal and renal parenchyma temperatures were monitored and maintained within 1° C of normal. Perfusates were University of Wisconsin solution (UW), Euro-Collins solution, normal saline solution, and Ringer's lactate solution. A nonperfused ischemic control and a nonischemic control group were also evaluated. Parameters evaluated included serum creatinine and blood urea nitrogen levels, renal ischemic injury grade, renal weight, and gross appearance of the injured kidney. Rats treated with UW solution were found to have a significantly lower creatinine, blood urea nitrogen, and injury grade than the other three perfused groups. The external gross appearance of the UW-treated kidneys was normal, whereas that of the other groups demonstrated moderate to severe injury. Although the mean right/left renal weight difference of the UW-treated group was lower than that of the other three groups, this was not statistically significant. Under normothermic conditions in rats, UW solution affords significant renal protection from ischemia. Euro-Collins, normal saline, and Ringer's lactate solutions display no significant protective effect.Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995. 相似文献
999.
1000.