全文获取类型
收费全文 | 1652篇 |
免费 | 149篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 75篇 |
妇产科学 | 31篇 |
基础医学 | 180篇 |
口腔科学 | 71篇 |
临床医学 | 225篇 |
内科学 | 299篇 |
皮肤病学 | 16篇 |
神经病学 | 85篇 |
特种医学 | 149篇 |
外科学 | 183篇 |
综合类 | 46篇 |
一般理论 | 3篇 |
预防医学 | 184篇 |
眼科学 | 30篇 |
药学 | 107篇 |
中国医学 | 1篇 |
肿瘤学 | 101篇 |
出版年
2023年 | 14篇 |
2021年 | 38篇 |
2020年 | 30篇 |
2019年 | 28篇 |
2018年 | 25篇 |
2017年 | 29篇 |
2016年 | 33篇 |
2015年 | 34篇 |
2014年 | 44篇 |
2013年 | 51篇 |
2012年 | 64篇 |
2011年 | 69篇 |
2010年 | 59篇 |
2009年 | 43篇 |
2008年 | 66篇 |
2007年 | 89篇 |
2006年 | 68篇 |
2005年 | 47篇 |
2004年 | 47篇 |
2003年 | 57篇 |
2002年 | 42篇 |
2001年 | 69篇 |
2000年 | 49篇 |
1999年 | 39篇 |
1998年 | 47篇 |
1997年 | 30篇 |
1996年 | 42篇 |
1995年 | 33篇 |
1994年 | 34篇 |
1993年 | 34篇 |
1992年 | 42篇 |
1991年 | 22篇 |
1990年 | 39篇 |
1989年 | 26篇 |
1988年 | 37篇 |
1987年 | 34篇 |
1986年 | 29篇 |
1985年 | 19篇 |
1984年 | 18篇 |
1983年 | 11篇 |
1982年 | 16篇 |
1981年 | 11篇 |
1980年 | 17篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1974年 | 10篇 |
1973年 | 14篇 |
1972年 | 9篇 |
1970年 | 9篇 |
排序方式: 共有1824条查询结果,搜索用时 121 毫秒
71.
Frans van Workum Laura Fransen Misha DP Luyer Camiel Rosman 《World journal of gastroenterology : WJG》2018,24(44):4974-4978
Surgical innovation and pioneering are important for improving patient outcome, but can be associated with learning curves. Although learning curves in surgery are a recognized problem, the impact of surgical learning curves is increasing, due to increasing complexity of innovative surgical procedures, the rapid rate at which new interventions are implemented and a decrease in relative effectiveness of new interventions compared to old interventions. For minimally invasive esophagectomy(MIE), there is now robust evidence that implementation can lead to significant learning associated morbidity(morbidity during a learning curve, that could have been avoided if patients were operated by surgeons that have completed the learning curve). This article provides an overview of the evidence of the impact of learning curves after implementation of MIE. In addition, caveats for implementation and available evidence regarding factors that are important for safe implementation and safe pioneering of MIE are discussed. 相似文献
72.
Jinlei Li Matthew Ogrodnik Sherral Devine Sanford Auerbach Philip A. Wolf Rhoda Au 《Alzheimer's & dementia》2018,14(1):35-42
Introduction
With a rapidly aging population, general practitioners are confronting the challenge of how to determine those who are at greatest risk for dementia and potentially need more specialized follow-up to mitigate symptoms early in its course. We created a practical dementia risk score and provided individualized estimates of future dementia risk.Methods
Using the Framingham Heart Study data, we built our prediction model using Cox proportional hazard models and developed a point system for the risk score and risk estimates.Results
The score system used total points ranging from ?1 to 31 and stratifies individuals into different levels of risk. We estimated 5-, 10-, and 20-year dementia risk prediction and incorporated these into the points system.Discussion
This risk score system provides a practical tool because all included predictors are easy to assess by practitioners. It can be used to estimate future probabilities of dementia for individuals. 相似文献73.
Teus J Weijs Jelle P Ruurda Grard AP Nieuwenhuijzen Richard van Hillegersberg Misha DP Luyer 《World journal of gastroenterology : WJG》2013,19(39):6509-6514
Esophagectomy,the surgical removal of all or part of the esophagus,is a surgical procedure that is associated with high morbidity and mortality.Pulmonary complications are an especially important postoperative problem.Therefore,many perioperative strategies to prevent pulmonary complications after esophagectomy have been investigated and introduced in daily clinical practice.Here,we review these strategies,including improvement of patient performance and technical advances such as minimally invasive surgery that have been implemented in recent years.Furthermore,interventions such as methylprednisolone,neutrophil elastase inhibitor and epidural analgesia,which have been shown to reduce pulmonary complications,are discussed.Benefits of the commonly applied routine nasogastric decompression,delay of oral intake and prophylactic mechanical ventilation are unclear,and many of these strategies are also evaluated here.Finally,we will discuss recent insights and new developments aimed to improve pulmonary outcomes after esophagectomy. 相似文献
74.
Jake Shortt Mark N. Polizzotto Neil Waters Marija Borosak Martine Moran Mary Comande Alexandra Devine Damien J. Jolley Erica M. Wood 《Transfusion》2009,49(11):2296-2303
BACKGROUND: Careful planning is essential to ensure blood availability during shortages. Triaging supply is one proposed strategy; however, few data concerning the urgency of transfusion are available to inform planning. This study sought to determine the proportion of red blood cells (RBCs) used for clinically urgent indications.
STUDY DESIGN AND METHODS: A total of 5132 RBC units were randomly selected at point of production and distributed into general statewide inventory over a 9-month period. These selected units carried case report forms, for completion at the point of hospital issue for transfusion. Completed forms were returned to the blood service for collation and analysis, capturing information on indication and clinical urgency of supply, including use for potentially deferrable elective surgery.
RESULTS: Data from 5052 RBC units indicated that 95.6% were transfused. Approximately one-third of transfused units were used to support surgery, one-third for hematology/oncology, and one-third for other medical and miscellaneous indications. Where used for surgery, 25.7% (95% confidence interval [CI], 23.4%-28.0%) were for elective procedures, although urgency of surgery was unknown in 17.1% (95% CI, 15.2%-19.2%) of cases. Supply for nonurgent medical indications and elective surgery only accounted for 9.8% (95% CI, 9.0%-10.6%) of use, with 53.4% (95% CI, 52.0%-54.8%) of RBCs required within 24 hours.
CONCLUSIONS: The majority of RBCs are transfused with a high degree of clinical urgency, with only a minor proportion required to support elective surgery. 相似文献
STUDY DESIGN AND METHODS: A total of 5132 RBC units were randomly selected at point of production and distributed into general statewide inventory over a 9-month period. These selected units carried case report forms, for completion at the point of hospital issue for transfusion. Completed forms were returned to the blood service for collation and analysis, capturing information on indication and clinical urgency of supply, including use for potentially deferrable elective surgery.
RESULTS: Data from 5052 RBC units indicated that 95.6% were transfused. Approximately one-third of transfused units were used to support surgery, one-third for hematology/oncology, and one-third for other medical and miscellaneous indications. Where used for surgery, 25.7% (95% confidence interval [CI], 23.4%-28.0%) were for elective procedures, although urgency of surgery was unknown in 17.1% (95% CI, 15.2%-19.2%) of cases. Supply for nonurgent medical indications and elective surgery only accounted for 9.8% (95% CI, 9.0%-10.6%) of use, with 53.4% (95% CI, 52.0%-54.8%) of RBCs required within 24 hours.
CONCLUSIONS: The majority of RBCs are transfused with a high degree of clinical urgency, with only a minor proportion required to support elective surgery. 相似文献
75.
Peter Schubert Jonathan N. Thon Geraldine M. Walsh Cindy H.I. Chen Edwin D. Moore Dana V. Devine Juergen Kast 《Transfusion》2009,49(9):1944-1955
BACKGROUND: The term platelet storage lesion (PSL) describes the structural and biochemical changes in platelets (PLTs) during storage. These are typified by alterations of morphologic features and PLT metabolism leading to reduced functionality and hence reduced viability for transfusion. While the manifestations of the storage lesion are well characterized, the biochemical pathways involved in the initiation of this process are unknown.
STUDY DESIGN AND METHODS: A complementary proteomic approach has recently been applied to analyze changes in the PLT proteome during storage. By employing stringent proteomic criteria, 12 proteins were identified as significantly and consistently changing in relative concentration over a 7-day storage period. Microscopy, Western blot analysis, flow cytometry, and PLT functionality analyses were used to unravel the involvement of a subset of these 12 proteins, which are connected through integrin signaling in one potential signaling pathway underlying storage lesion development.
RESULTS: Microscopic analysis revealed changes in localization of glycoprotein IIIa, Rap1, and talin during storage. Rap1 activation was observed to correlate with expression of the PLT activation marker CD62P. PLTs incubated for 7 days with the PI3-kinase inhibitor LY294002 showed diminished Rap1 activation as well as a moderate reduction in integrin αIIbβ3 activation and release of α-granules. Furthermore, this inhibitor seemed to improve PLT integrity and quality during storage as several in vitro probes showed a deceleration of PLT activation.
CONCLUSION: These results provide the first evidence for a signaling pathway mediating PSL in which PI3-kinase–dependent Rap1 activation leads to integrin αIIbβ3 activation and PLT degranulation. 相似文献
STUDY DESIGN AND METHODS: A complementary proteomic approach has recently been applied to analyze changes in the PLT proteome during storage. By employing stringent proteomic criteria, 12 proteins were identified as significantly and consistently changing in relative concentration over a 7-day storage period. Microscopy, Western blot analysis, flow cytometry, and PLT functionality analyses were used to unravel the involvement of a subset of these 12 proteins, which are connected through integrin signaling in one potential signaling pathway underlying storage lesion development.
RESULTS: Microscopic analysis revealed changes in localization of glycoprotein IIIa, Rap1, and talin during storage. Rap1 activation was observed to correlate with expression of the PLT activation marker CD62P. PLTs incubated for 7 days with the PI3-kinase inhibitor LY294002 showed diminished Rap1 activation as well as a moderate reduction in integrin αIIbβ3 activation and release of α-granules. Furthermore, this inhibitor seemed to improve PLT integrity and quality during storage as several in vitro probes showed a deceleration of PLT activation.
CONCLUSION: These results provide the first evidence for a signaling pathway mediating PSL in which PI3-kinase–dependent Rap1 activation leads to integrin αIIbβ3 activation and PLT degranulation. 相似文献
76.
Use of Recombinant Envelope Proteins for Serological Diagnosis of Dengue Virus Infection in an Immunochromatographic Assay 下载免费PDF全文
Andrea J. Cuzzubbo Timothy P. Endy Ananda Nisalak Siripen Kalayanarooj David W. Vaughn Steven A. Ogata David E. Clements Peter L. Devine 《Clinical and Vaccine Immunology : CVI》2001,8(6):1150-1155
An immunochromatographic test that incorporates recombinant antigens (Dengue Duo Rapid Strip Test; PanBio, Brisbane, Australia) has recently become commercially available. This assay is performed in 15 min and detects both immunoglobulin M (IgM) and IgG in a capture format. The four recombinant proteins used represent the N-terminal 80% of the viral envelope glycoproteins of dengue viruses 1, 2, 3, and 4, respectively. The sensitivity and specificity of the recombinant-antigen-based assay were 90 and 86%, respectively. The similar diagnostic performance of these antigens to that of enzyme-linked immunosorbent assays using whole dengue virus suggests that they mimic whole dengue viruses in primary structure and epitope conformation. These results suggest that recombinant proteins can be used in diagnostic assays for dengue to overcome safety issues associated with the use of whole virus. 相似文献
77.
TonyDevine 《中国健康教育》1999,15(3):42-45
婚前性行为,即使像意外怀孕或性病(包括艾滋病)等躯体的不良后果能加以避免,也难免留下心理上的阴影。很少有人公开谈论婚前性行为所造成的心理影响,这种影响,通常深藏在潜意识的层次上。了解婚前性关系的负面心理效应,有助于性教育工作者、父母、教师更好地引导我... 相似文献
78.
Lina Panayiota Aristoteli BSc Mark DP Willcox PhD 《Clinical & experimental ophthalmology》2001,29(3):143-146
The purpose of this study was to compare the adhesion of Pseudomonas aeruginosa ocular isolates to mucin. An adhesion assay was developed using biotin‐labelled P. aeruginosa strains (two corneal ulcer, two acute red eye, one asymptomatic and one standard strains) incubated with porcine gastric mucin immobilized on a nitrocellulose membrane. The adhesion was semiquantified using densitometry. The results showed that all P. aeruginosa strains tested were able to adhere to mucin to various extents with three strains (one corneal ulcer, one acute red eye, one asymptomatic) binding significantly greater than the negative control (P < 0.1). Results suggest that ocular strains of P. aeruginosa strains differ in their adhesion to mucin but this did not correlate with the pathogenic origin of the strain. It is concluded that the adhesion of P. aeruginosa strains to mucin alone may not be a principal determinant of pathogenesis but may be a contributing factor along with other bacterial virulence traits. 相似文献
79.
80.