全文获取类型
收费全文 | 464篇 |
免费 | 35篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 31篇 |
妇产科学 | 5篇 |
基础医学 | 52篇 |
口腔科学 | 36篇 |
临床医学 | 52篇 |
内科学 | 99篇 |
皮肤病学 | 2篇 |
神经病学 | 17篇 |
特种医学 | 18篇 |
外科学 | 69篇 |
综合类 | 10篇 |
预防医学 | 14篇 |
眼科学 | 18篇 |
药学 | 41篇 |
1篇 | |
肿瘤学 | 29篇 |
出版年
2023年 | 5篇 |
2022年 | 16篇 |
2021年 | 12篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 19篇 |
2017年 | 13篇 |
2016年 | 17篇 |
2015年 | 15篇 |
2014年 | 11篇 |
2013年 | 19篇 |
2012年 | 30篇 |
2011年 | 31篇 |
2010年 | 21篇 |
2009年 | 25篇 |
2008年 | 30篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 17篇 |
2004年 | 16篇 |
2003年 | 9篇 |
2002年 | 22篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有499条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
On the Acylation of Hydroxy- and Mercaptocarboxylic Acid Esters Using the Carbodiimide/Acylation Catalyst Method Acylation of esters of hydroxycarboxylic acids can be carried out easily and in good yields by using the carbodiimide/acylation catalyst method. The reaction has also been applied to dihydroxy- and mercaptocarboxylic acid esters. The compounds formed from certain esters of hydroxycarboxylic acids are unstable to heat and decompose easily to the free carboxylic acid. No racemization is observed when using enantiomeric hydroxycarboxylic acids. Use of racemic carboxylic acids leads to diastereomers, whose 1H-NMR shifts for characteristic protons are different as expected. Five drugs are among the carboxylic acids investigated in this context. 相似文献
5.
Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model 总被引:3,自引:0,他引:3
David E. Rosow M.D. Dushyant Sahani M.D. Oliver Strobel M.D. Sanjeeva Kalva M.D. Mari Mino-Kenudson M.D. Nagaraj S. Holalkere M.D. Guido Alsfasser M.D. Sanjay Saini M.D. Susanna I. Lee M.D. Peter R. Mueller M.D. Carlos Fernándezdel Castillo M.D. Andrew L. Warshaw M.D. Sarah P. Thayer M.D. Ph.D. 《Journal of gastrointestinal surgery》2005,9(9):1262-1275
Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical
outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography
is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive
but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly
facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately
demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization
of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols.
After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT
angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including
poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findingsd—compared
with pathologic diagnosesd—predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA
holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.
Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18,
2005 (oral presentation).
Supported by the Karin Grunebaum Research Fellowship, Harvard Medical School (D.E.R.), the German Research Fellowship, German
Research Foundation STR 690/1-1 (O.S.), and the Phillip H. Meyers Grant from the Society of Gastrointestinal Radiologists
(S.P.T.). 相似文献
6.
D Kanjilal M A Basir R S Verma B K Rajegowda R Lala A Nagaraj 《Journal of medical genetics》1992,29(9):669-670
We report a new case of Rubinstein-Taybi syndrome with a hypoplastic right kidney, persistent pulmonary hypertension, and mitral valve regurgitation. Other pertinent features included broad thumbs, broad big toes, syndactyly of the third and fourth fingers bilaterally, beaked nose, broad columella of the nose, patent ductus arteriosus, and motor and mental retardation. The testes were descended. The 3 month old patient had delayed motor and mental development corresponding to a 1 month old infant. 相似文献
7.
Rectal prolapse in infants and children 总被引:1,自引:0,他引:1
Rectal prolapse that is intractable to the usual medical therapy was successfully managed without significant complications in 10 patients by simple subcutaneous encirclement of the anus with a heavy nonabsorbable suture, which was in place until the suture was removed or broke after 4 to 6 months. Four patients required two sutures and one needed a third insertion. Since this procedure is simple, has no serious complications, and controls rectal prolapse, it is recommended as the preferred initial surgical treatment of this condition. 相似文献
8.
Cosma A Bühler S Nagaraj R Staib C Hammarin AL Wahren B Goebel FD Erfle V Sutter G 《Clinical and diagnostic laboratory immunology》2004,11(2):406-410
Vaccination against smallpox is again considered in order to face a possible bioterrorist threat, but the nature and the level of the immune response needed to protect a person from smallpox after vaccination are not totally understood. Therefore, simple, rapid, and accurate assays to evaluate the immune response to vaccinia virus need to be developed. Neutralization assays are usually considered good predictors of vaccine efficacy and more informative with regard to protection than binding assays. Currently, the presence of neutralizing antibodies to vaccinia virus is measured using a plaque reduction neutralization test, but this method is time-consuming and labor-intensive and has a subjective readout. Here, we describe an innovative neutralization assay based on a modified vaccinia virus Ankara (MVA) vector expressing the green fluorescent protein (MVA-gfp). This MVA-gfp neutralization assay is rapid and sensitive and has a high-throughput potential. Thus, it is suitable to monitor the immune response and eventually the efficacy of a large campaign of vaccination against smallpox and to study the vector-specific immune response in clinical trials that use genetically engineered vaccinia viruses. Most importantly, application of the highly attenuated MVA eliminates the safety concern in using the replication-competent vaccinia virus in the standard clinical laboratory. 相似文献
9.
Ante mortem diagnosis of human rabies using saliva samples: comparison of real time and conventional RT-PCR techniques. 总被引:1,自引:0,他引:1
T Nagaraj Joel P Vasanth Anita Desai Anupa Kamat S N Madhusudana V Ravi 《Journal of clinical virology》2006,36(1):17-23
BACKGROUND: Rabies is an enzootic and fatal disease and is still a major problem in developing countries. Ante mortem diagnosis in human cases is necessary for medical management of the patient and to ensure appropriate post-exposure treatment of contacts. Both conventional RT-PCR and Real time PCR (TaqMan) have been described for the detection of rabies virus RNA from saliva and tissue respectively, however to date, there have been no studies comparing conventional and real time PCR assays for detection of rabies virus nucleic acid using saliva samples for ante mortem diagnosis. OBJECTIVES: In this study, we evaluated the utility of conventional RT-PCR and SYBR Green I Real time PCR in the ante mortem diagnosis of rabies using saliva samples. STUDY DESIGN: Saliva samples collected from twenty-four patients presenting with typical clinical manifestations of rabies were tested in the two assays. RESULTS: Amongst the 24 samples tested, 21 samples (87.5%) were positive by either of the two molecular methods. Of these 21, rabies virus RNA was detected in 6/21 in the conventional RT-PCR assay while SYBR Green I Real time PCR could detect RNA in 18/21 samples. CONCLUSION: Real time PCR assay was more sensitive than conventional RT-PCR assay (sensitivity 75% versus 37%, p=0.0189). This study highlights the utility of molecular diagnostic tests in establishing ante mortem diagnosis of rabies using saliva samples within a few hours. 相似文献
10.