全文获取类型
收费全文 | 3195篇 |
免费 | 212篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 150篇 |
妇产科学 | 71篇 |
基础医学 | 449篇 |
口腔科学 | 92篇 |
临床医学 | 286篇 |
内科学 | 740篇 |
皮肤病学 | 59篇 |
神经病学 | 294篇 |
特种医学 | 87篇 |
外科学 | 369篇 |
综合类 | 34篇 |
一般理论 | 2篇 |
预防医学 | 180篇 |
眼科学 | 123篇 |
药学 | 223篇 |
中国医学 | 16篇 |
肿瘤学 | 227篇 |
出版年
2024年 | 2篇 |
2023年 | 56篇 |
2022年 | 86篇 |
2021年 | 192篇 |
2020年 | 111篇 |
2019年 | 152篇 |
2018年 | 183篇 |
2017年 | 139篇 |
2016年 | 134篇 |
2015年 | 111篇 |
2014年 | 152篇 |
2013年 | 208篇 |
2012年 | 278篇 |
2011年 | 263篇 |
2010年 | 176篇 |
2009年 | 125篇 |
2008年 | 195篇 |
2007年 | 187篇 |
2006年 | 159篇 |
2005年 | 121篇 |
2004年 | 129篇 |
2003年 | 92篇 |
2002年 | 82篇 |
2001年 | 13篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 12篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有3428条查询结果,搜索用时 312 毫秒
1.
2.
3.
R Srikanth D Mukunda Reddy A Mosahebi 《Journal of plastic, reconstructive & aesthetic surgery》2006,59(12):1318-1324
The numbers of free flap donor site as well as their indications are constantly increasing. Despite increasing popularity of microvascular reconstructive procedures, literature lacks clear and objective outcome criteria. This paper reports on a simple outcome classification that has become a routine part of the unit's large workload of microvascular outcome recording. The classification was formed through a retrospective analysis of 241 consecutive cases from 2000 to 2001 and is a five graded numerical classification. Grade 1 equates to total success without co-morbidity and grade 5 to a major complication such as amputation, etc., whatever the status of the flap itself. From 2002 to 2005 the classification was prospectively used on 527 consecutive cases with ease of integration into routine clinical practice. The Classification would enable a more objective record keeping thus analysis of the outcome. It would allow a more realistic comparison of different techniques or donor types as well set a benchmarking level for further improvement of the results. 相似文献
4.
Ashwin A Kallianpur Rajinder Parshad Maya Dehran Priya Hazrah 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(2):229-234
BACKGROUND AND OBJECTIVES: Feasibility of ambulatory laparoscopic inguinal hernia repair in developing countries is not known due to lack of dedicated outpatient centers. This study prospectively evaluated the feasibility of outpatient discharge after laparoscopic total extraperitoneal inguinal hernia repair done in combination with in-hospital services and its impact on quality of life. METHODS: Forty patients were studied who had uncomplicated inguinal hernias and fulfilled the selection criteria. Quality of life was evaluated by using the SF-12 questionnaire. RESULTS: Ninety percent of patients could be discharged as outpatients. Four patients required admission. No major complications or readmissions occurred. Physical components of quality of life deteriorated in the immediate postoperative period but improved to above preoperative levels within one month. A transient deterioration in subgroups of the mental health component was observed, which recovered to normal in less than a week. There was no significant alteration in the emotional component. There has been no recurrence at a median follow-up of 25 months. CONCLUSION: It was feasible to safely perform outpatient TEP in combination with routine in-hospital services without increasing complications or causing any adverse impact on quality of life. This was possible subject to adherence to proper selection and discharge criteria. 相似文献
5.
Edward Black Jason Niamat Srikanth Boddu Antonio Martin-Ucar John P Duffy William Ellis Morgan Francis David Beggs 《European journal of cardio-thoracic surgery》2006,29(2):244-247
OBJECTIVE: There are limited and conflicting data available concerning the incidence of inadvertent splenectomy and its impact on the outcome in patients who have undergone oesophagectomy. The aim of this study is to identify the factors associated with a likelihood of inadvertent splenectomy and its influence on early and long-term outcome in patients having oesophagectomy for oesophageal carcinoma. METHODS: A consecutive series of 738 oesophagectomies performed between 1991 and 2004 was analysed. In our practice, the spleen was removed only if damaged intraoperatively. Routine chemo- and immunoprophylaxis would subsequently be used. Multivariate analysis with logistic and Cox models determined significant variables. RESULTS: Of the 738 oesophagectomies, 48 (6.5%) had splenectomy. Neoadjuvant chemotherapy was administered to a minority of patients; none subsequently had splenectomy. There were significant differences between types of operation (Ivor-Lewis 18 (9.0%), left thoracolaparotomy 14 (9.9%) and left thoracophrenotomy 15 (3.9%), p=0.01). Splenectomy was more common with advanced N stage disease (OR=0.44 [0.20-0.95]; p=0.04). Splenectomy resulted in more blood transfusions (median, 2 units vs 0 units; p=0.03) more anastomotic leaks (7 [14.6%] vs 42 [6.1%]; p=0.02) but not an increase in pulmonary complications (p=0.64) or in-hospital mortality (1 [4.6%] vs 37 [5.4%]; p=0.30). Splenectomy did not significantly affect median survival (551 [332-770] days vs 627 [554-700] days; p=0.63). CONCLUSION: Although inadvertent splenectomy increased the morbidity of oesophagectomy, it did not impair survival. Type of operation and advanced N stage are important risks for splenectomy. Though best avoided, most of the consequences of splenectomy can be managed. An unexpected relationship between splenectomy and anastomotic leaks needs further investigation. 相似文献
6.
7.
Alterations in xenobiotic metabolizing enzymes in brain and liver of rats coexposed to endosulfan and malathion 总被引:4,自引:0,他引:4
The effects of endosulfan (3 mg kg-1 body wt., i.p.) and malathion (30 mg kg-1 body wt.) and their coexposure on rat hepatic and brain xenobiotic metabolizing enzymes were investigated. Endosulfan was found to induce aminopyrine-n-demethylase (81%) and aniline hydroxylase (59%) activities significantly in liver and to a lesser extent in brain. Malathion treatment induced malathion carboxylesterase activity in both liver (50%) and brain (22%), significantly depleted liver glutathione (35%) content with stimulation of glutathione-S-transferase (50%) and inhibited the activity of mixed-function oxidases. In the coexposed animals, malathion's inhibitory influence on mixed-function oxidases and endosulfan's inhibitory effect on malathion carboxylesterase were found to dominate, while endosulfan potentiated the activity of glutathione-S-transferase significantly in liver (69%) and brain. A similar trend of alteration in coexposed brain was found, but to a lesser extent. A significant inhibition in brain acetylcholine esterase activity (42%) in the coexposed animals suggests that endosulfan may potentiate the toxicity of malathion by interfering with glutathione and carboxylesterase routes of malathion detoxification. 相似文献
8.
Listeria--review of epidemiology and pathogenesis. 总被引:2,自引:0,他引:2
Vidhya Ramaswamy Vincent Mary Cresence Jayan S Rejitha Mohandas Usha Lekshmi K S Dharsana Suryaprasad Priya Prasad Helan Mary Vijila 《Journal of microbiology, immunology, and infection》2007,40(1):4-13
Listeria monocytogenes (commonly called Listeria) is a Gram-positive facultatively intracellular foodborne pathogen often found in food and elsewhere in nature. It can cause a rare but serious disease called listeriosis, especially among pregnant women, the elderly or individuals with a weakened immune system. In serious cases, it can lead to brain infection and even death. Listeria is more likely to cause death than other bacteria that cause food poisoning. In fact, 20 to 30% of food borne listeriosis infections in high-risk individuals may be fatal. Recent technological developments have increased the ability of scientists to identify the cause of foodborne illnesses. L. monocytogenes has been used as a model organism for the study of intracellular parasitism. Whilst the basic mechanisms of cellular pathogenesis have been elucidated by a series of elegant studies, recent research has begun to focus upon the gastrointestinal phase of L. monocytogenes infection. Epidemiological studies of outbreaks of human disease now demonstrate that the pathogen can cause gastroenteritis in the absence of invasive disease and associated mortality. Elucidation of whole genome sequences and virulence determinants have greatly contributed to understanding of the organism and its infection pathways. 相似文献
9.
HGT1 encodes a high-affinity glutathione transporter in the yeast Saccharomyces cerevisiae that is induced under sulphur limitation. The present work demonstrates that repression by organic sulphur sources is under the control of the classic sulphur regulatory network, as seen by the absence of expression in a met4 background. Cysteine appeared to be the principal regulatory molecule, since elevated levels were seen in str4 strains (deficient in cysteine biosynthesis) that could be repressed by elevated levels of cysteine, but not by methionine or glutathione. Investigations into cis-regulatory elements revealed that the previously described motif, a 9-bp cis element, CCGCCACAC, located at the –356 to –364 region of the promoter could in fact be refined to a 7-bp CGCCACA motif that is also repeated at –333 to –340. The second copy of this motif was essential for activity, since mutations in the core region of the second copy completely abolished activity and regulation by sulphur sources. Activity, but not regulation, could be restored by reintroducing an additional copy upstream of the first copy. A third region, GCCGTCTGCAAGGCA, conserved in the HGT1 promoters of the different Saccharomyces spp, was observed at –300 to –285 but, while mutations in this region did not lead to any loss in repression, the basal and induced levels were significantly increased. In contrast to a previous report, no evidence was found for regulation by the VDE endonuclease. The strong repression at the transport level by glutathione seen in strains overexpressing HGT1 was due to a glutathione-dependent toxicity in these cells. 相似文献
10.
DNA vaccine encoding human immunodeficiency virus-1 Gag, targeted to the major histocompatibility complex II compartment by lysosomal-associated membrane protein, elicits enhanced long-term memory response 总被引:1,自引:0,他引:1 下载免费PDF全文
Antigen presentation by major histocompatibility complex type II (MHC II) molecules and activation of CD4+ helper T cells are critical for the generation of immunological memory. We previously described a DNA vaccine encoding human immunodeficiency virus-1 p55Gag as a chimera with the lysosome-associated membrane protein (LAMP/gag). The LAMP/gag chimera protein traffics to the MHC II compartment of transfected cells and elicits enhanced immune responses as compared to a DNA vaccine encoding native gag not targeted to the MHC II compartment. We have now investigated the long-term responses of immunized mice and show that the LAMP/gag DNA vaccine promotes long-lasting B cell- and CD4+ and CD8+ T-cell memory responses induced by DNA encoding non-targeted Gag decay rapidly and elicit very low or undetectable levels of gag DNA is sufficient to generate T-cell memory. Following this initial priming immunization with LAMP/gag DNA, booster immunizations with native gag DNA or the LAMP/gag chimera are equally efficient in eliciting B- and T-cell secondary responses, results in accordance with observations that secondary expansion of CD8+ cells in the boost phase does not require additional CD4+ help. These findings underscore the significance of targeting DNA-encoded vaccine antigens to the MHC II processing compartments for induction of long-term immunological memory. 相似文献