全文获取类型
收费全文 | 13248篇 |
免费 | 1175篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 436篇 |
妇产科学 | 273篇 |
基础医学 | 1997篇 |
口腔科学 | 312篇 |
临床医学 | 1094篇 |
内科学 | 2700篇 |
皮肤病学 | 176篇 |
神经病学 | 1442篇 |
特种医学 | 449篇 |
外科学 | 2088篇 |
综合类 | 287篇 |
一般理论 | 12篇 |
预防医学 | 1123篇 |
眼科学 | 316篇 |
药学 | 871篇 |
中国医学 | 9篇 |
肿瘤学 | 674篇 |
出版年
2021年 | 167篇 |
2020年 | 96篇 |
2019年 | 173篇 |
2018年 | 190篇 |
2017年 | 134篇 |
2016年 | 132篇 |
2015年 | 165篇 |
2014年 | 263篇 |
2013年 | 475篇 |
2012年 | 593篇 |
2011年 | 645篇 |
2010年 | 399篇 |
2009年 | 326篇 |
2008年 | 696篇 |
2007年 | 708篇 |
2006年 | 721篇 |
2005年 | 741篇 |
2004年 | 764篇 |
2003年 | 767篇 |
2002年 | 726篇 |
2001年 | 214篇 |
2000年 | 182篇 |
1999年 | 210篇 |
1998年 | 183篇 |
1997年 | 160篇 |
1996年 | 153篇 |
1995年 | 153篇 |
1994年 | 161篇 |
1993年 | 139篇 |
1992年 | 212篇 |
1991年 | 181篇 |
1990年 | 169篇 |
1989年 | 187篇 |
1988年 | 183篇 |
1987年 | 135篇 |
1986年 | 188篇 |
1985年 | 195篇 |
1984年 | 191篇 |
1983年 | 178篇 |
1982年 | 171篇 |
1981年 | 189篇 |
1980年 | 169篇 |
1979年 | 115篇 |
1978年 | 152篇 |
1977年 | 102篇 |
1976年 | 124篇 |
1975年 | 128篇 |
1974年 | 101篇 |
1973年 | 108篇 |
1972年 | 75篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
N. S. Kalson C. P. Charalambous E. S. Powell A. Hearnden J. K. Stanley 《Hand (New York, N.Y.)》2009,4(3):279-282
A common distal radio-ulnar joint (DRUJ) stabilisation procedure uses a tendon graft running from the lip of the radial sigmoid
notch to the ulnar fovea and through a bony tunnel to the ulnar shaft, before being wrapped round the distal ulna and sutured
to itself. Such graft fixation can be challenging and requires a considerable tendon length. The graft length could be reduced
by fixing the graft to the ulna using a bone anchor or interference screw. The aim of this study was to compare the strength
of three distal ulna graft fixation methods (tendon wrapping and suturing, bone anchor and interference screw). Four human
cadaveric ulnae were used. A tendon strip was run through a tunnel in the distal ulna and secured by: (1) wrapping round the
shaft and suturing it to itself, (2) a bone anchor and (3) an interference screw in the bone tunnel. Load to failure was determined
using a custom-made apparatus and an Instron machine. Maximum failure load was highest for the bone anchor fixation (99.3 ± 23.7 N)
followed by the suturing (96.2 ± 12.1 N), and the interference screw fixation (46.9 ± 5.6 N). There was no significant difference
between the tendon suturing and bone anchor methods, but the tendon suturing was statistically significantly higher compared
to the interference screw (P = 0.028). In performing anatomical stabilisation of the DRUJ fixation of the tendon graft to the distal ulna with a bone
anchor provides the most secure fixation. This may make the stabilisation technique less demanding and require a smaller tendon
graft. 相似文献
12.
The Usefulness of Magnetic Resonance Imaging in the Diagnosis of Anterolateral Impingement of the Ankle 总被引:3,自引:0,他引:3
LCDR Doug Duncan MD CAPT Tim Mologne MD CDR Hans Hildebrand MD Mark Stanley MD LT Richard Schreckengaust MD CAPT Dave Sitler MD 《The Journal of foot and ankle surgery》2006,45(5):304-307
The purpose of this study is to assess the sensitivity and specificity of magnetic resonance imaging (MRI) in the diagnosis of anterolateral impingement of the ankle and to assess the most helpful sequence in making the diagnosis. Twenty-four patients who had undergone ankle arthroscopy were chosen. Twelve patients had arthroscopically documented anterolateral impingement, and 12 patients with no impingement on arthroscopy served as controls. Two musculoskeletal radiologists and an orthopedic surgeon, blinded to the operative diagnosis, retrospectively reviewed selective MRI images in the sagittal, axial, and coronal planes. The sensitivities and specificities were calculated for all 3 reviewers. The Kendall coefficient of concordance was calculated for overall agreement among reviewers. Sensitivities varied from 0.75 to 0.83, whereas specificities varied from 0.75 to 1.00. Using the Fisher exact test of contingency, the sensitivities and specificities showed that all reviewers' interpretations were statistically significant with P = .039, .001, and .012, respectively. The axial images were felt to be most helpful in making the diagnosis. The physicians felt that the sagittal images were helpful in 67%, 83%, and 100%, respectively. MRI is a useful tool that can aid the clinician in the diagnosis of anterolateral impingement of the ankle. T1 sagittal images demonstrating displacement of the normal fat signal anterior to the fibula by scar can be useful and help to confirm the diagnosis. 相似文献
13.
David S. Park Paul Manowitz Stanley Stein Ronald D. Poretz 《Alcoholism, clinical and experimental research》1996,20(2):234-239
Several electrophoretic forms of human platelet arylsulfatase A (ASA), including variant type IIIa and normal type IVa , have been identified by nondenaturing polyacrylamide gel electrophoresis. An alcoholic population that we have analyzed is enriched in variant type IIIa compared with nonalcoholic psychiatric and normal controls. Individuals with the IIIa enzyme possess greatly reduced levels of ASA activity. To understand further the structural basis for the differences and their potential biological consequences, the nature of the ASA variant expressed by fibroblasts from different individuals was explored. The electrophoretic patterns of fibroblast ASA from the IIIa and IVa individuals differ in degree of phosphorylation. Furthermore, fibroblast ASA from IIIa individuals lacks an N -linked glycan found in ASA from IVa individuals. In addition, differences in peptide and/or posttranslational modification unrelated to the N -linked carbohydrate or phosphorylation exist between the fibroblast ASA from IIIa and IVa individuals. The finding that both fibroblasts and platelets exhibit related electrophoretic isoform patterns characteristic of the donor's ASA type allows for the use of fibroblasts to study the impact of ethanol on the metabolism of cells possessing different ASA types. 相似文献
14.
15.
16.
17.
High-Temperature Short-Time Heat Inactivation of HIV and Other Viruses in Human Blood Plasma 总被引:4,自引:0,他引:4
Stanley E. Charm Steven Landau Bolanle Williams Bernard Horowitz Alfred M. Prince and Donna Pascual 《Vox sanguinis》1992,62(1):12-20
An ultra-short-time heating system was used to process blood plasma spiked with various viruses (HIV, vesicular stomatitis virus, encephalomyocarditis virus). Virus reduction and recovery of plasma proteins were measured at various temperatures from 65 to 85 degrees C. Processing at 77 degrees C and 0.006 s resulted in a high level of virus kill, including greater than or equal to 4.4 log10 HIV, while maintaining protein structure and activity essentially intact. 相似文献
18.
BACKGROUND: Somatosensory evoked potentials (SSEPs) have long been recognized as an excellent tool for detecting neural and vascular compromise during vascular, neurosurgical and orthopedic procedures. SSEPs have the ability to localize, central versus peripheral, the area of compromise. Many surgeons use only lower-limb SSEP monitoring when performing lumbar spinal surgery. The upper extremities are usually not monitored during such procedures, and monitoring oxygen saturation does not detect neural compromise. PURPOSE: To report that the expanded use of SSEP monitoring during surgery can be beneficial in detecting peripheral ischemia or neural compromise resulting from positioning. STUDY DESIGN: Three case reviews of orthopedic spine surgeries where SSEP monitoring provided early warnings of vascular and neural compression. METHODS: The cases review three different lumbar procedures in which evidence of peripheral ischemia and nerve compression were detected by SSEP monitoring. RESULTS: By the use of upper- and lower-extremity monitoring during lumbar procedures, early detection of ischemia and nerve compression were noted intraoperatively. These changes prompted examination of the patient and repositioning to correct the ischemia or compression. The repositioning in these cases corrected the problem, and no lasting effects were found. CONCLUSIONS: Including SSEP monitoring of the bilateral upper extremities should be considered during lumbar spinal procedures. Such monitoring can be offered for a slightly increased expense and only minimal time delay to place the additional required electrodes by the technician. As a direct result of the early warning of the SSEP monitoring, we were able to avoid potential ischemic injuries and improve patient outcomes. 相似文献
19.
We studied eight cases of apparent subarachnoid injection of local anesthetic through the optic nerve sheath and subsequent spread to the parabrainstem cisterns and the contralateral optic nerve sheath. The patients all experienced bilateral decrease in vision and ophthalmoplegia, and variable degrees of central nervous system symptoms and respiratory depression. The complications occurred with a variety of local anesthetic agents and with sharp disposable needles in six of the eight cases. These cases demonstrated the spectrum of signs and symptoms that may follow optic nerve sheath injection of local anesthetic agents. 相似文献
20.
Sean J. Barnett M.S. M.D. Christopher Stanley B.S. Melanie Hanlon R.N. C.N.P. Robert Acton M.D. Daniel A. Saltzman M.D. Ph.D. Sayeed Ikramuddin M.D. Henry Buchwald M.D. Ph.D. 《Surgery for obesity and related diseases》2005,1(4):1609-398
PURPOSE: Obesity has become a health-care crisis in the United States. Adolescent obesity is now one of the most common childhood disorders, with 4.7 million American adolescents having a body mass index (BMI) greater than the 95th percentile. Most patients do not respond to diet modification or exercise programs and attention is now turning toward surgery as a source of weight loss in adolescents. Few studies have looked at the overall morbidity and mortality of weight loss surgery in this patient population. METHODS: This is a retrospective study of medical charts of 15 bariatric surgical procedures performed on 14 adolescents without known genetic syndromes associated with severe childhood obesity from 1971 to 2001 at the University of Minnesota. Procedures performed on these patients included vertical banded gastroplasty (n = 7), Roux-en-Y gastric bypass (n = 5), and jejunoileal bypass (n = 3). Jejunoileal bypass procedures were performed from 1971 to 1977, after which time this procedure was abandoned. Patient age ranged from 13 to 17 years (mean, 15.7 years). Mean follow-up time was 6 years, with 9 patients available for long-term follow-up. RESULTS: All procedures were performed using an open technique by 1 surgeon. There were no perioperative deaths; complications included 1 case of wound infection, 2 episodes of dumping syndrome that resolved without revision, 1 episode of hypoglycemia, and 1 case of short-term electrolyte imbalance in a patient who underwent jejunoileal bypass. The average BMI dropped from 58.5 +/- 13.7 to 32.1 +/- 9.7 kg/m(2) (P < .01)--a 45% reduction. CONCLUSIONS: Surgery for morbid obesity is safe and results in significant weight loss in adolescents who fail medical therapy. 相似文献