全文获取类型
收费全文 | 2955篇 |
免费 | 151篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 129篇 |
妇产科学 | 145篇 |
基础医学 | 337篇 |
口腔科学 | 44篇 |
临床医学 | 178篇 |
内科学 | 675篇 |
皮肤病学 | 79篇 |
神经病学 | 169篇 |
特种医学 | 111篇 |
外科学 | 473篇 |
综合类 | 64篇 |
预防医学 | 117篇 |
眼科学 | 210篇 |
药学 | 225篇 |
1篇 | |
中国医学 | 5篇 |
肿瘤学 | 140篇 |
出版年
2023年 | 28篇 |
2022年 | 34篇 |
2021年 | 79篇 |
2020年 | 59篇 |
2019年 | 59篇 |
2018年 | 79篇 |
2017年 | 63篇 |
2016年 | 62篇 |
2015年 | 72篇 |
2014年 | 100篇 |
2013年 | 112篇 |
2012年 | 180篇 |
2011年 | 193篇 |
2010年 | 108篇 |
2009年 | 77篇 |
2008年 | 163篇 |
2007年 | 166篇 |
2006年 | 130篇 |
2005年 | 132篇 |
2004年 | 127篇 |
2003年 | 85篇 |
2002年 | 75篇 |
2001年 | 64篇 |
2000年 | 64篇 |
1999年 | 61篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 20篇 |
1993年 | 14篇 |
1992年 | 40篇 |
1991年 | 47篇 |
1990年 | 38篇 |
1989年 | 39篇 |
1988年 | 47篇 |
1987年 | 35篇 |
1986年 | 34篇 |
1985年 | 17篇 |
1984年 | 23篇 |
1983年 | 15篇 |
1982年 | 14篇 |
1981年 | 19篇 |
1979年 | 30篇 |
1977年 | 15篇 |
1975年 | 14篇 |
1974年 | 17篇 |
1973年 | 28篇 |
1972年 | 35篇 |
1971年 | 16篇 |
1970年 | 27篇 |
1967年 | 13篇 |
排序方式: 共有3114条查询结果,搜索用时 31 毫秒
41.
42.
43.
Free floating ball thrombus in left atrium 总被引:1,自引:0,他引:1
44.
Pregnancy following a period of infertility was considered to be an increased risk for the fetus. During a period of 3 years (1983-85), 748 couples were seen at this infertility clinic; 515 women (68.9%) conceived, and were followed up and studied prospectively. Fifteen of these women moved out of the area. We analysed the results of pregnancies for the remaining 500, (Group 1) and compared them with the outcome for the total obstetric population (Group 2) during the same period. Mean age at conception in the infertility group (Group 1) was 31.8 (+/- 2.7, 2 SD) years, as compared with 23.7 (+/- 2.9, 2 SD) in the total hospital obstetric population (Group 2) (p less than 0.05). The incidences of spontaneous abortion for the two groups (8 and 6.2%) did not differ (p greater than 0.05). However, the incidence of ectopic pregnancy was higher (3.0%) in Group 1 than in Group 2 (1.5%) (p less than 0.01). The incidence of pre-existing hypertensive vascular disease (7.7%) complicating pregnancy and multiple pregnancy (4.1%) was significantly higher in Group 1 than in Group 2 (1.5% and 1.4% respectively), (p less than 0.01). The incidences of induction of labor (29.5%) and elective operative delivery (10.6%) were higher in Group 1 (p less than 0.01). The incidences of infants with birth weight below the tenth centile (12.9%), of fetal distress in labor (14.6%) and a low Apgar score (0-5) (9.5%), were higher in Group 1, but there was no difference in the perinatal mortality rate between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
45.
Two hundred fifty subfertile men with idiopathic oligospermia (count less than 20 million/ml) were treated with mesterolone (100-150 mg/day) for 12 months. Seminal analysis were assayed 3 times and serum follicle stimulating hormone (FSH) luteinizing hormone (LH) and plasma testosterone were assayed once before treatment and repeated at 3, 6, 9 and 12 months after the initiation of treatment. One hundred ten patients (44%) had normal serum FSH, LH and plasma testosterone, 85 patients (34%) had low serum FSH, LH and low plasma testosterone. One hundred seventy-five patients (70%) had moderate oligospermia (count 5 to less than 20 million/ml) and 75 patients (30%) had severe oligospermia (count less than 5 million/ml). Seventy-five moderately oligospermic patients showed significant improvement in the sperm density, total sperm count and motility following mesterolone therapy whereas only 12% showed improvement in the severe oligospermic group. Mesterolone had no depressing effect on low or normal serum FSH and LH levels but had depressing effect on 25% if the levels were elevated. There was no significant adverse effect on testosterone levels or on liver function. One hundred fifteen (46%) pregnancies resulted following the treatment, 9 of 115 (7.8%) aborted and 2 (1.7%) had ectopic pregnancy. Mesterolone was found to be more useful in patients with a sperm count ranging between 5 and 20 million/ml. Those with severe oligospermia (count less than 5 million) do not seem to benefit from this therapy. 相似文献
46.
We report a case of a 39-year-old human immunodeficiency virus (HIV)--negative male who presented with a progressively increasing swelling in the left hypochondrium. He did not manifest fever or toxaemic symptoms. Computerised tomographic scan (CT scan) of the abdomen revealed an abscess in the anterior wall and multiple splenic abscesses. Fine needle aspiration from the abscesses in the anterior abdominal wall and the spleen confirmed the diagnosis of tuberculosis as the aetiology. The patient responded well to antituberculosis treatment and the abscesses regressed considerably. 相似文献
47.
Structural and functional abnormalities in the islets isolated from type 2 diabetic subjects 总被引:15,自引:0,他引:15
Deng S Vatamaniuk M Huang X Doliba N Lian MM Frank A Velidedeoglu E Desai NM Koeberlein B Wolf B Barker CF Naji A Matschinsky FM Markmann JF 《Diabetes》2004,53(3):624-632
Type 2 diabetic subjects manifest both disordered insulin action and abnormalities in their pancreatic islet cells. Whether the latter represents a primary defect or is a consequence of the former is unknown. To examine the beta-cell mass and function of islets from type 2 diabetic patients directly, we isolated islets from pancreata of type 2 diabetic cadaveric donors (n = 14) and compared them with islets from normal donors (n = 14) matched for age, BMI, and cold ischemia time. The total recovered islet mass from type 2 diabetic pancreata was significantly less than that from nondiabetic control subjects (256,260 islet equivalents [2,588 IEq/g pancreas] versus 597,569 islet equivalents [6,037 IEq/g pancreas]). Type 2 diabetic islets were also noted to be smaller on average, and histologically, islets from diabetic patients contained a higher proportion of glucagon-producing alpha-cells. In vitro study of islet function from diabetic patients revealed an abnormal glucose-stimulated insulin release response in perifusion assays. In addition, in comparison with normal islets, an equivalent number of type 2 diabetic islets failed to reverse hyperglycemia when transplanted to immunodeficient diabetic mice. These results provide direct evidence for abnormalities in the islets of type 2 diabetic patients that may contribute to the pathogenesis of the disease. 相似文献
48.
Intraocular pressure control and complications with two-stage insertion of the Baerveldt implant 总被引:1,自引:0,他引:1
PURPOSE: To evaluate intraocular pressure (IOP) control and the prevalence of complications associated with the two-stage insertion of the Baerveldt implant. DESIGN: Retrospective, noncomparative, interventional case series. METHODS: We reviewed the medical records of all patients who underwent the two-stage Baerveldt implantation for advanced glaucoma between January 1995 and November 1998 at the Doheny Eye Institute, Los Angeles, California. All eyes with a minimum of 6 months of follow-up were included in the study. Eyes that failed before 6 months after stage II were also included in the study. MAIN OUTCOME MEASURES: The criterion for surgical success was postoperative IOP of 6 mmHg or more and 21 mmHg or less on two or more consecutive measurements with or without the use of glaucoma medications and without loss of light perception or further surgical intervention to lower IOP. RESULTS: Nineteen eyes from 19 patients were included. Median postoperative follow-up was 17 months (range, 3-56 months). The cumulative probability of success was 89% at both 12 and 24 months. The median preoperative IOP of 21 mmHg (range, 12-33 mmHg) was reduced to a median postoperative IOP of 12 mmHg (range, 1-17 mmHg; P < 0.0001). The median number of glaucoma medications before surgery was three and after surgery was one (P < 0.0001). Visual acuity remained the same or improved in 13 eyes (68%). One eye experienced hypotony (5%), and in two eyes (11%) suprachoroidal hemorrhages developed. CONCLUSIONS: The two-stage insertion of the Baerveldt implant effectively reduced IOP, produced few complications, and preserved visual acuity in more than two thirds of eyes with advanced glaucomatous damage. 相似文献
49.
50.
We tested the hypothesis that the initial functional residual capacity (FRC) of preterm infants with hyaline membrane disease (HMD) could predict the response to surfactant replacement (Survanta, 4 mL/kg/dose), with a better initial FRC being correlated with a greater improvement in PaO2, a/A PO2 ratio, and FRC. Thirty-four preterm infants were studied on 41 occasions. FRC and arterial blood gases were measured immediately prior to treatment. FRC was measured by the helium dilution method. Arterial blood gases were measured again after 30, 60, and 120 minutes. FRC was measured after 120 minutes. Twenty-seven treatments resulted in an increase in PaO2 >10 mmHg (responders); 14 did not (nonresponders). There was no correlation between initial FRC, change in FRC, and change in PaO2 (r2 = 0.07). These results suggest that there is no relationship between initial FRC and response to surfactant treatment. 相似文献