全文获取类型
收费全文 | 201887篇 |
免费 | 2780篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 1461篇 |
儿科学 | 7386篇 |
妇产科学 | 3563篇 |
基础医学 | 19950篇 |
口腔科学 | 2174篇 |
临床医学 | 15071篇 |
内科学 | 35805篇 |
皮肤病学 | 1107篇 |
神经病学 | 19104篇 |
特种医学 | 9928篇 |
外国民族医学 | 1篇 |
外科学 | 32802篇 |
综合类 | 2649篇 |
一般理论 | 20篇 |
预防医学 | 20342篇 |
眼科学 | 3243篇 |
药学 | 11591篇 |
中国医学 | 656篇 |
肿瘤学 | 17891篇 |
出版年
2022年 | 208篇 |
2021年 | 553篇 |
2020年 | 307篇 |
2019年 | 563篇 |
2018年 | 22463篇 |
2017年 | 17772篇 |
2016年 | 19926篇 |
2015年 | 1475篇 |
2014年 | 1643篇 |
2013年 | 1900篇 |
2012年 | 8718篇 |
2011年 | 22673篇 |
2010年 | 19718篇 |
2009年 | 12396篇 |
2008年 | 21026篇 |
2007年 | 23249篇 |
2006年 | 2196篇 |
2005年 | 3822篇 |
2004年 | 4886篇 |
2003年 | 5678篇 |
2002年 | 3791篇 |
2001年 | 706篇 |
2000年 | 866篇 |
1999年 | 623篇 |
1998年 | 515篇 |
1997年 | 436篇 |
1996年 | 278篇 |
1995年 | 294篇 |
1994年 | 281篇 |
1993年 | 217篇 |
1992年 | 267篇 |
1991年 | 302篇 |
1990年 | 351篇 |
1989年 | 316篇 |
1988年 | 302篇 |
1987年 | 251篇 |
1986年 | 235篇 |
1985年 | 244篇 |
1984年 | 203篇 |
1983年 | 188篇 |
1982年 | 150篇 |
1981年 | 151篇 |
1980年 | 160篇 |
1979年 | 168篇 |
1978年 | 146篇 |
1977年 | 123篇 |
1975年 | 120篇 |
1973年 | 140篇 |
1971年 | 122篇 |
1970年 | 123篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
Dan Greitz 《Child's nervous system》2007,23(5):487-489
Objective This study aims to question the generally accepted cerebrospinal fluid (CSF) bulk flow theory suggesting that the CSF is exclusively
absorbed by the arachnoid villi and that the cause of hydrocephalus is a CSF absorption deficit. In addition, this study aims
to briefly describe the new hydrodynamic concept of hydrocephalus and the rationale for endoscopic third ventriculostomy (ETV)
in communicating hydrocephalus.
Critique The bulk flow theory has proven incapable of explaining the pivotal mechanisms behind communicating hydrocephalus. Thus, the
theory is unable to explain why the ventricles enlarge, why the CSF pressure remains normal and why some patients improve
after ETV.
Hydrodynamic concept of hydrocephalus Communicating hydrocephalus is caused by decreased intracranial compliance increasing the systolic pressure transmission into
the brain parenchyma. The increased systolic pressure in the brain distends the brain towards the skull and simultaneously
compresses the periventricular region of the brain against the ventricles. The final result is the predominant enlargement
of the ventricles and narrowing of the subarachnoid space. The ETV reduces the increased systolic pressure in the brain simply
by venting ventricular CSF through the stoma. The patent aqueduct in communicating hydrocephalus is too narrow to vent the
CSF sufficiently. 相似文献
82.
Christian Waydhas Dieter Nast-Kolb Steffen Ruchholtz 《European journal of trauma and emergency surgery》2007,33(2):170-175
Abstract
Objective: To define the diagnostic accuracy of clinical examination in patients with impaired consciousness or endotracheal intubation
to detect pelvic ring fractures and to identify those with severe bleeding.
Methods: Included in this prospective data collection with retrolective data analysis were a consecutive series of blunt trauma victims
with either a Glasgow Coma Scale ≤ 13 or tracheal intubation. Clinical examination comprised testing for stability of the
iliac wings.
Results: From 784 subjects (injury severity score 23.3 ± 17.4) 93 patients (11.9%) were found to have a pelvic ring fracture. Clinical
instability of the pelvic ring was found in 42 patients. There was only one false positive. Fifty-two fractures could not
be identified by clinical examination, including nine fractures (17%) that required surgical fracture stabilization (sensitivity
of clinical examination 44.1%). Seventeen fractures (18.3%) were associated with a blood loss larger than 20% of circulating
blood volume. Sixteen of those were identified by clinical instability of the pelvic ring (sensitivity 94.1%, specificity
97.0%, positive predictive value 38.1%, negative predictive value 99.9%).
Conclusions: Clinical examination for stability of the pelvis in this selected group of patients missed a significant number of pelvic
ring fractures including fractures that require surgical stabilization. The finding of a clinically unstable identifies most
of the patients with the pelvic ring fracture being a major source of bleeding. A stable pelvis makes pelvic ring fracture
as being the source of bleeding quite unlikely. 相似文献
83.
Alemtuzumab (CAMPATH 1H) Induction Therapy in Cadaveric Kidney Transplantation—Efficacy and Safety at Five Years 总被引:2,自引:0,他引:2
Christopher J. E. Watson J. Andrew Bradley Peter J. Friend John Firth Craig J. Taylor John R. Bradley Kenneth G. C. Smith Sathia Thiru Neville V. Jamieson Geoff Hale Herman Waldmann Roy Calne 《American journal of transplantation》2005,5(6):1347-1353
Alemtuzumab is a powerful lymphocyte depleting antibody currently being evaluated in solid organ transplantation. This paper describes 5-year results of a single center study of alemtuzumab as induction in renal transplantation. Thirty-three renal transplant recipients received 20 mg alemtuzumab on day 0 and 1, followed by half-dose cyclosporin monotherapy (trough concentration 75-125 ng/mL) from day 3. They were compared in a retrospective contemporaneous-controlled manner with 66 kidney transplant recipients transplanted in the same period and center who received conventional immunosuppression with cyclosporin, azathioprine and prednisolone. In the alemtuzumab group 12% of recipients died compared to 17% in the control group (p = 0.48); likewise graft loss was similar in both groups (21% vs. 26%, respectively, p = 0.58). Incidence of acute rejection was also comparable at 5 years (31.5% vs. 33.6%), although the pattern of rejection was different with 14% patients in the alemtuzumab group experiencing rejection over 1 year post-transplant compared to none in the control group. There was no significant difference between groups in terms of infection or serious adverse events. While acknowledging the limitations of a relatively small single-center study, results suggest that alemtuzumab induction allowed satisfactory long-term patient and graft survival equivalent to that seen with standard triple immunosuppression, while avoiding steroid therapy. 相似文献
84.
Background
Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population. 相似文献85.
AIM: To undertake a systematic review of the diagnostic performance of clinical examination, sample acquisition and sample analysis in infected foot ulcers in diabetes. METHODS: Nineteen electronic databases plus other sources were searched. To be included, studies had to fulfil the following criteria: (i) compare a method of clinical assessment, sample collection or sample analysis with a reference standard; (ii) recruit diabetic individuals with foot ulcers; (ii) present 2 x 2 diagnostic data. Studies were critically appraised using a 12-item checklist. RESULTS: Three eligible studies were identified, one each on clinical examination, sample collection and sample analysis. For all three, study groups were heterogeneous with respect to wound type and a small proportion of participants had foot ulcers due to diabetes. No studies identified an optimum reference standard. Other methodological problems included non-blind interpretation of tests and the time lag between index and reference tests. Individual signs or symptoms of infection did not prove to be useful tests when assessed against punch biopsy as the reference standard. The wound swab did not perform well when assessed against tissue biopsy. Semiquantitative analysis of wound swab might be a useful alternative to quantitative analysis. The limitations of these findings and their impact on recommendations from relevant clinical guidelines are discussed. CONCLUSION: Given the importance of this topic, it is surprising that only three eligible studies were identified. It was not possible to describe the optimal methods of diagnosing infection in diabetic patients with foot ulceration from the evidence identified in this systematic review. 相似文献
86.
87.
88.
Birgitta Malmberg Göran Kecklund Björn Karlson Roger Persson Per Flisberg Palle Ørbaek 《BMC health services research》2010,10(1):239
Background
It is well known that physicians' night-call duty may cause impaired performance and adverse effects on subjective health, but there is limited knowledge about effects on sleep duration and recovery time. In recent years occupational stress and impaired well-being among anaesthesiologists have been frequently reported for in the scientific literature. Given their main focus on handling patients with life-threatening conditions, when on call, one might expect sleep and recovery to be negatively affected by work, especially in this specialist group. The aim of the present study was to examine whether a 16-hour night-call schedule allowed for sufficient recovery in anaesthesiologists compared with other physician specialists handling less life-threatening conditions, when on call. 相似文献89.
David Berrigan Linda W Pickle Jennifer Dill 《International journal of health geographics》2010,9(1):20
Background
Past studies of associations between measures of the built environment, particularly street connectivity, and active transportation (AT) or leisure walking/bicycling have largely failed to account for spatial autocorrelation of connectivity variables and have seldom examined both the propensity for AT and its duration in a coherent fashion. Such efforts could improve our understanding of the spatial and behavioral aspects of AT. We analyzed spatially identified data from Los Angeles and San Diego Counties collected as part of the 2001 California Health Interview Survey. 相似文献90.
Sebastiana Z. Kalula G. H. Swingler A. A. Sayer M. Badri M. Ferreira 《The journal of nutrition, health & aging》2010,14(4):319-323