全文获取类型
收费全文 | 3352篇 |
免费 | 189篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 99篇 |
妇产科学 | 63篇 |
基础医学 | 488篇 |
口腔科学 | 62篇 |
临床医学 | 239篇 |
内科学 | 722篇 |
皮肤病学 | 79篇 |
神经病学 | 277篇 |
特种医学 | 286篇 |
外国民族医学 | 1篇 |
外科学 | 426篇 |
综合类 | 61篇 |
预防医学 | 235篇 |
眼科学 | 47篇 |
药学 | 267篇 |
中国医学 | 11篇 |
肿瘤学 | 156篇 |
出版年
2022年 | 29篇 |
2021年 | 40篇 |
2020年 | 26篇 |
2019年 | 35篇 |
2018年 | 53篇 |
2017年 | 42篇 |
2016年 | 60篇 |
2015年 | 69篇 |
2014年 | 87篇 |
2013年 | 103篇 |
2012年 | 136篇 |
2011年 | 151篇 |
2010年 | 127篇 |
2009年 | 112篇 |
2008年 | 131篇 |
2007年 | 131篇 |
2006年 | 121篇 |
2005年 | 120篇 |
2004年 | 109篇 |
2003年 | 124篇 |
2002年 | 112篇 |
2001年 | 120篇 |
2000年 | 115篇 |
1999年 | 85篇 |
1998年 | 56篇 |
1997年 | 55篇 |
1996年 | 47篇 |
1995年 | 45篇 |
1994年 | 36篇 |
1993年 | 32篇 |
1992年 | 50篇 |
1991年 | 37篇 |
1990年 | 55篇 |
1989年 | 60篇 |
1988年 | 66篇 |
1987年 | 65篇 |
1986年 | 62篇 |
1985年 | 50篇 |
1984年 | 31篇 |
1983年 | 37篇 |
1982年 | 31篇 |
1981年 | 24篇 |
1980年 | 28篇 |
1979年 | 39篇 |
1978年 | 41篇 |
1977年 | 24篇 |
1976年 | 26篇 |
1975年 | 27篇 |
1973年 | 21篇 |
1971年 | 21篇 |
排序方式: 共有3552条查询结果,搜索用时 15 毫秒
1.
2.
Henk R Franke F Froukje Snaaijer Paul W H Houben Marius J van der Mooren 《Gynecological endocrinology》2006,22(12):692-697
OBJECTIVE: To assess the effects of adding combined estradiol/norethisterone acetate therapy (CENT) to goserelin acetate treatment (GA) of dysfunctional uterine bleeding (DUB) in perimenopausal women. METHODS: In a randomized, placebo-controlled, double-blind trial followed by an open follow-up study, 31 perimenopausal women with DUB were recruited from gynecological outpatient departments of two Dutch hospitals and randomized for treatment with either GA/placebo or GA/CENT for 6 months followed by 18 months of GA/CENT for all. The main outcome measures were abdominal pain, number of bleeding days, double-layer endometrial thickness (DET), Greene climacteric score (GCS), visual analog scale for well-being, bone mineral density (BMD) and mammographic density (BI-RAD score). RESULTS: Abdominal pain, number of bleeding days and DET decreased in both groups, the between-group difference in decrease not being statistically significant. GCS initially showed significant improvement in the GA/CENT group. BMD decreased significantly in the GA/placebo group (-4.1%) compared with the GA/CENT group (-0.3%). Another 18 months of GA/CENT did not result in a lasting difference in BMD between groups. BI-RAD scores did not differ significantly between or within the two groups. CONCLUSIONS: Adding CENT to GA treatment for DUB in perimenopausal women initially prevented BMD loss and improved climacteric complaints, while having no negative impact on vaginal bleeding, abdominal pain or BI-RAD scores. However, prolonged treatment did not result in a lasting prevention of bone loss. 相似文献
3.
4.
M. H. Wernitz S. Swidsinski K. Weist D. Sohr W. Witte K-P. Franke D. Roloff H. Rüden S. K. Veit 《Clinical microbiology and infection》2005,11(6):457-465
Screening of potential MRSA-positive patients at hospital admission is recommended in German and international guidelines. This policy has been shown to be effective in reducing the frequency of nosocomial MRSA transmissions in the event of an outbreak, but the influence of screening on reducing hospital-acquired MRSA infections in a hospital setting where MRSA is endemic is not yet well-documented. This study describes the effect of hospital-wide screening of defined risk groups in a 700-bed acute care hospital during a period of 19 months. In a cohort study with a 19-month control period, the frequencies of hospital-acquired MRSA infections were compared with and without screening. In the control period, there were 119 MRSA-positive patients, of whom 48 had a hospital-acquired MRSA infection. On the basis of this frequency, a predicted total of 73.2 hospital-acquired MRSA infections was calculated for the screening period, but only 52% of the expected number (38 hospital-acquired MRSA infections) were observed, i.e., 48% of the predicted number of hospital-acquired MRSA infections were prevented by the screening programme. The screening programme was performed with minimal effort and can therefore be recommended as an effective measure to help prevent hospital-acquired MRSA infections. 相似文献
5.
6.
After p.o. administration of 5-piperidino-7-[N-pentyl-N-(beta- hydroxyethyl)]amino-s-triazolo[1,5-a]pyrimidine (1; AR 12463) more than 15 metabolites were isolated from urine and feces of male Wistar rats. Only small amounts of unchanged 1 were observed. The structure of 12 metabolites was elucidated or proposed on the basis of UV-, 13C NMR- and mass spectra. Main metabolites are 5-piperidin-4'-olyl-7-[N-pentyl-N-(beta- hydroxyethyl)]amino-s-triazolo[1,5-a]pyrimidine and 5-piperidin-4'-olyl-7-[N-pent-4-olyl-N-(beta-hydroxyet hyl)]amino-s- triazolo[1,5-a]pyrimidine. The other metabolites are mainly hydroxy- or ketopentyl derivatives and piperidinoles or piperidinones, respectively. Conjugates of most of the metabolites were identified, but the ratio phase-I/II metabolites was about 3:1. In contrast to trapidil, 5-methyl-7-diethylamino-s- triazolo[1,5-a]pyrimidine, no hydroxy derivatives of the bicyclic system were observed. The major part of unchanged 1 and metabolites is excreted via kidneys. 相似文献
7.
C L Franke J C van Swieten J van Gijn 《Stroke; a journal of cerebral circulation》1991,22(12):1530-1533
BACKGROUND AND PURPOSE: We investigated the residual abnormalities on computed tomography in a series of patients with proven intracerebral hemorrhage to determine whether the type of lesion is related to the site and size of the initial hematoma. METHODS: In a partially prospective follow-up study, we studied computed tomographic scans of 42 patients with spontaneous intracerebral hemorrhage after 2-24 (median 9) months. RESULTS: Lobar hemorrhages had occurred in 20 patients; the other 22 hemorrhages were in the basal ganglia or thalamus. No residual lesions were found on seven scans (17%), despite residual handicap in three of these seven patients (slight, moderate, and moderately severe). In five cases, the scan showed only focal atrophy, and in two there were only focal calcifications. There were six patients with slit-like lesions (only after deep hemorrhages), 12 with rounded and isolated hypodense areas, and 10 with rounded hypodense areas connected to the ventricular system. The connection between the residual lesion and the ventricular system depended to a large extent on the size of the initial hematoma, but very little on whether it had initially ruptured into the ventricular system. CONCLUSIONS: A retrospective diagnosis of cerebral hemorrhage on radiological grounds can be made with confidence only in a small group of patients with slit-like lesions in the basal ganglia. This diagnosis is impossible in approximately one third of cerebral hemorrhages because the abnormalities are aspecific or have completely disappeared. 相似文献
8.
E MOLKE JENSEN K. A. THIESSEN AA. CHRISTENSEN 《Acta anaesthesiologica Scandinavica》1986,30(2):109-110
The effect of 4 mg oral naloxone on preoperative gastric volume and pH of gastric aspirate was studied in a double-blind, randomized study. Twenty patients received 10 ml of naloxone (4 mg) mixed with 10 ml of orange juice, and 20 patients received 10 ml of isotonic saline mixed with 10 ml of orange juice, 2 h before surgery. Gastric content was obtained immediately after intubation of the trachea. No significant difference in gastric volume and pH of gastric aspirate was found between the two groups. It is concluded that naloxone does not affect gastric emptying and gastric acid secretion to a degree great enough to protect against aspiration of gastric contents into the lungs. 相似文献
9.
10.