全文获取类型
收费全文 | 1166篇 |
免费 | 77篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 84篇 |
妇产科学 | 27篇 |
基础医学 | 103篇 |
口腔科学 | 33篇 |
临床医学 | 179篇 |
内科学 | 244篇 |
皮肤病学 | 17篇 |
神经病学 | 56篇 |
特种医学 | 247篇 |
外科学 | 86篇 |
综合类 | 22篇 |
预防医学 | 46篇 |
眼科学 | 14篇 |
药学 | 36篇 |
中国医学 | 5篇 |
肿瘤学 | 47篇 |
出版年
2024年 | 4篇 |
2023年 | 11篇 |
2022年 | 8篇 |
2021年 | 19篇 |
2020年 | 11篇 |
2019年 | 24篇 |
2018年 | 31篇 |
2017年 | 17篇 |
2016年 | 28篇 |
2015年 | 26篇 |
2014年 | 39篇 |
2013年 | 36篇 |
2012年 | 32篇 |
2011年 | 32篇 |
2010年 | 38篇 |
2009年 | 60篇 |
2008年 | 44篇 |
2007年 | 26篇 |
2006年 | 24篇 |
2005年 | 19篇 |
2004年 | 19篇 |
2003年 | 23篇 |
2002年 | 19篇 |
2001年 | 23篇 |
2000年 | 18篇 |
1999年 | 15篇 |
1998年 | 49篇 |
1997年 | 52篇 |
1996年 | 65篇 |
1995年 | 48篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 14篇 |
1991年 | 7篇 |
1990年 | 14篇 |
1989年 | 34篇 |
1988年 | 30篇 |
1987年 | 32篇 |
1986年 | 33篇 |
1985年 | 23篇 |
1984年 | 15篇 |
1983年 | 9篇 |
1982年 | 22篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 13篇 |
排序方式: 共有1250条查询结果,搜索用时 0 毫秒
51.
Morphological analysis of degeneration and regeneration of syncytiotrophoblast in first trimester placental villi during organ culture 总被引:3,自引:1,他引:3
We have recently shown using dansyl-L-lysine exclusion studies that the
release of human chorionic gonadotrophin (HCG) in conjunction with L-
lactate dehydrogenase (LDH) from first trimester villi during organ culture
is symptomatic of syncytiotrophoblast degeneration. The purpose of this
study was to examine chorionic villi at the ultrastructural level in order
to determine events occurring during organ culture. The tissue was sampled
after 0, 24, 48 and 120 h in culture and processed for electron microscopy.
In addition to confirming the previously recorded syncytial degeneration,
the electron micrographs showed clearly the generation of a new
syncytiotrophoblast layer. The new layer, derived from differentiating
cytotrophoblast cells, was largely formed by 48 h and was maintained for at
least 120 h in culture. This study demonstrates a model which provides an
opportunity to study the differentiation of cytotrophoblast cells whilst
they retain their anatomical relationships within the villous structure.
相似文献
52.
目的 探讨勃脉力A注射液对体外循环心脏手术患者肝功能的影响.方法 选择术前肝功能正常、无肝炎病史的行体外循环心脏手术患者60名,随机分为勃脉力A组(P组)和林格液组(R组).所有患者均在术前、术后2h、1d、3d、7d分别采肘正中静脉血和挠动脉血:静脉血分离血清后应用自动血生化分析仪检测血清中天冬氨酸转氨酶和丙氨酸氨基转移酶,以了解患者的肝脏功能改变;抽取动脉血查乳酸浓度.术中及术后密切观察患者血压、心率、中心静脉压、尿量等,观察并记录患者拔管及停留ICU时间.结果 与R组相比较,在术后各时间点P组ALT、AST及乳酸浓度均显著降低(P﹤0.05),并且拔除气管导管时间和停留ICU时间均有所缩短.结论 勃脉力A注射液能够显著降低体外循环术中乳酸浓度,并能改善患者肝功能,非常适用于体外循环手术. 相似文献
53.
BACKGROUND: Some patients with endometriosis are candidates for sympathectomy of the superior hypogastric plexus. The objective of this paper is to describe our technique of laparoscopic presacral neurolysis for sympathectomy and to report 1 year results of the first 15 cases. METHODS: To achieve this objective in a prospective observational study of 1 year follow-up; we performed laparoscopic presacral chemical neurolysis with phenol in 15 patients with pelvic pain and minimal-moderate endometriosis. The main outcome measures were: the impact of treatment on pelvic symptom resolution, non-opioid analgesic consumption during menses, sexual performance and observed complications and side effects during 1 year follow-up. RESULTS: We noted a significant reduction in total pelvic symptom score as compared with baseline mean (SD) of 9.04 (1.2). The mean difference [95% confidence interval (CI)] of reduction was 5.7 (4.9-6.5), 5.8 (5.0-6.6) and 5.8 (4.9-6.6) from the baseline at the 3rd, 6th and 12th postoperative month (P < 0.001). We observed a significant improvement in Sabbatberg Sexual Rating Scale as compared with baseline mean (SD) of 30.9 (4.3). The mean difference (95% CI) of increase was 33.4 (30.3-36.4), 33.2 (30.1-36.2) and 33.2 (30.1-36.3) from the baseline at the 3rd, 6th and 12th postoperative month. We observed a significant reduction in analgesic consumption during menses in terms of total naproxen sodium tablets as compared with baseline mean (SD) of 8.9 (1.1). The mean difference (95% CI) of reduction in the total number of naproxen sodium 250 mg tablets was 6.5 (5.5-7.5), 6.7 (5.7-7.7) and 6.6 (5.6-7.6) from the baseline at the 3rd, 6th and 12th postoperative month. The most common side effect was constipation. CONCLUSION: Laparoscopic presacral neurolysis is feasible and simple. More data is needed to support its efficacy and safety. 相似文献
54.
55.
56.
57.
58.
59.
ME Penny 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(S383):114-120
It has been suggested that proliferation of enterobacteriaceae and/or anaerobes in the duodenum of some children with acute diarrhoea determines whether the episode becomes persistent. A review of published studies and the comparison of cultures of duodenal aspirates from Peruvian children with acute and persistent diarrhoea and diarrhoea-free children did not support this hypothesis. Although many children had enterobacteriaceae and/or anaerobes cultured there was no correlation with clinical and nutritional outcome. Age, nutritional status, the environment and the aetiology of the episode were determinants of the duodenal microflora independent of diarrhoea. Culture of the duodenal aspirates did not increase the yield of enteropathogens which were isolated more frequently from stools than from the duodenum. Despite the presence of a single strain or serotype of enterobacteriaceae suggesting that these bacteria were colonizing the duodenum, we were unable to demonstrate any adherence mechanisms in the majority of them. Two often bacteria with no other evidence of virulence caused diarrhoea in the RITARD rabbit model. 相似文献
60.
Altiparmak MR Ataman R Ozaras R Tahan V Aydin S Uzun H Serdengecti K Soysal T 《Renal failure》2002,24(1):29-35
BACKGROUND AND AIM: Although the majority of patients with end stage renal failure have anemia, some have relative erythrocytosis. Patients treated with continuous ambulatory peritoneal dialysis (CAPD) having relative erythrocytosis were studied in order to determine the factors that would be responsible. METHODS: Nine out of 89 CAPD patients (10%) were identified as having relative erythrocytosis. Age-, sex- and duration of disease-matched eight patients undergoing CAPD were taken as control. Beside factors of etiologies of renal failure, smoking, renal cysts, viral hepatitides, residual renal function, the adequacy of CAPD, nutritional status, hypertension, serum levels of erythropoietin, IL-1, IL-6, TNF-, and IGF-1 levels were also investigated. RESULTS: Relative erythrocytosis occurred most often in diabetic and amyloidosis patients. None of the parameters studied were found to be significantly different between groups. During 2-year follow-up, although statistically non-significant, patients having relative erythrocytosis seemed to have higher mortality rate due to vascular complications. CONCLUSION: No single factor seemed to explain erythrocytosis in patients undergoing CAPD. Being diabetic or with amyloidosis may increase the risk. 相似文献