全文获取类型
收费全文 | 3298篇 |
免费 | 174篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 138篇 |
妇产科学 | 40篇 |
基础医学 | 377篇 |
口腔科学 | 82篇 |
临床医学 | 344篇 |
内科学 | 589篇 |
皮肤病学 | 72篇 |
神经病学 | 179篇 |
特种医学 | 117篇 |
外科学 | 776篇 |
综合类 | 82篇 |
一般理论 | 4篇 |
预防医学 | 130篇 |
眼科学 | 136篇 |
药学 | 176篇 |
中国医学 | 13篇 |
肿瘤学 | 235篇 |
出版年
2023年 | 34篇 |
2022年 | 68篇 |
2021年 | 136篇 |
2020年 | 63篇 |
2019年 | 115篇 |
2018年 | 117篇 |
2017年 | 92篇 |
2016年 | 92篇 |
2015年 | 96篇 |
2014年 | 154篇 |
2013年 | 148篇 |
2012年 | 254篇 |
2011年 | 246篇 |
2010年 | 159篇 |
2009年 | 127篇 |
2008年 | 187篇 |
2007年 | 202篇 |
2006年 | 188篇 |
2005年 | 176篇 |
2004年 | 182篇 |
2003年 | 119篇 |
2002年 | 103篇 |
2001年 | 42篇 |
2000年 | 50篇 |
1999年 | 39篇 |
1998年 | 28篇 |
1997年 | 23篇 |
1996年 | 29篇 |
1995年 | 27篇 |
1994年 | 24篇 |
1993年 | 14篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 14篇 |
1989年 | 8篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1986年 | 17篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1976年 | 7篇 |
1974年 | 11篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1970年 | 6篇 |
排序方式: 共有3533条查询结果,搜索用时 281 毫秒
31.
Nicole Schneider Charles Fisher Andrew Glennie Jennifer Urquhart John Street Marcel Dvorak Scott Paquette Raphaele Charest-Morin Tamir Ailon Neil Manson Ken Thomas Parham Rasoulinejad Raja Rampersaud Chris Bailey 《The spine journal》2021,21(5):821-828
BACKGROUND CONTEXTThe indication to perform a fusion and decompression surgery as opposed to decompression alone for lumbar degenerative spondylolisthesis (LDS) remains controversial. A variety of factors are considered when deciding on whether to fuse, including patient demographics, radiographic parameters, and symptom presentation. Likely surgeon preference has an important influence as well.PURPOSEThe aim of this study was to assess factors associated with the decision of a Canadian academic spine surgeon to perform a fusion for LDS.STUDY DESIGN/SETTINGThis study is a retrospective analysis of patients prospectively enrolled in a multicenter Canadian study that was designed to evaluate the assessment and surgical management of LDS.PATIENT SAMPLEInclusion criteria were patients with: radiographic evidence of LDS and neurogenic claudication or radicular pain, undergoing posterior decompression alone or posterior decompression and fusion, performed in one of seven, participating academic centers from 2015 to 2019.OUTCOME MEASURESPatient demographics, patient-rated outcome measures (Oswestry Disability Index [ODI], numberical rating scale back pain and leg pain, SF-12), and imaging parameters were recorded in the Canadian Spine Outcomes Research Network (CSORN) database. Surgeon factors were retrieved by survey of each participating surgeon and then linked to their specific patients within the database.METHODSUnivariate analysis was used to compare patient characteristics, imaging measures, and surgeon variables between those that had a fusion and those that had decompression alone. Multivariate backward logistic regression was used to identify the best combination of factors associated with the decision to perform a fusion.RESULTSThis study includes 241 consecutively enrolled patients receiving surgery from 11 surgeons at 7 sites. Patients that had a fusion were younger (65.3±8.3 vs. 68.6±9.7 years, p=.012), had worse ODI scores (45.9±14.7 vs. 40.2±13.5, p=.007), a smaller average disc height (6.1±2.7 vs. 8.0±7.3 mm, p=.005), were more likely to have grade II spondylolisthesis (31% vs. 14%, p=.008), facet distraction (34% vs. 60%, p=.034), and a nonlordotic disc angle (26% vs. 17%, p=.038). The rate of fusion varied by individual surgeon and practice location (p<.001, respectively). Surgeons that were fellowship trained in Canada more frequently fused than those who fellowship trained outside of Canada (76% vs. 57%, p=.027). Surgeons on salary fused more frequently than surgeons remunerated by fee-for-service (80% vs. 64%, p=.004). In the multivariate analysis the clinical factors associated with an increased odds of fusion were decreasing age, decreasing disc height, and increasing ODI score; the radiographic factors were grade II spondylolisthesis and neutral or kyphotic standing disc type; and the surgeon factors were fellowship location, renumeration type and practice region. The odds of having a fusion surgery was more than two times greater for patients with a grade II spondylolisthesis or neutral and/or kyphotic standing disc type (opposed to lordotic standing disc type). Patients whose surgeon completed their fellowship in Canada, or whose surgeon was salaried (opposed to fee-for-service), or whose surgeon practiced in western Canada had twice the odds of having fusion surgery.CONCLUSIONSThe decision to perform a fusion in addition to decompression for LDS is multifactorial. Although patient and radiographic parameters are important in the decision-making process, multiple surgeon factors are associated with the preference of a Canadian spine surgeon to perform a fusion for LDS. Future work is necessary to decrease treatment variability between surgeons and help facilitate the implementation of evidence-based decision making. 相似文献
32.
Clinical and experimental observations suggest that opiates can exert different influences on the perception of stimuli from distinct sensory modalities. Thermally-induced nociception is classically responsive to opiate agonists. mu-Opioid receptor-deficient transgenic mice are more sensitive to thermal nociceptive stimuli and morphine fails to attenuate the nociceptive responses to thermal stimuli in these animals. To enhance our understanding of opiate influences on mechanical sensitivity, we have examined withdrawal responses to a sequence of ascending forces of mechanical stimuli in mice with normal (wild type), half-normal (heterozygous) and absent (homozygous) mu-opioid receptor levels. We report data from mice examined without drug pretreatment or following pretreatment with morphine, the selective kappa-opioid agonist, U50488H, and the selective delta-opioid agonist, DPDPE. Saline-pretreated mice of each genotype displayed similar, monotonically increasing frequency of withdrawal responses to the graded stimuli. Subcutaneously administered morphine produced a dose-dependent reduction in withdrawal responses in wild type and heterozygous mice, but had no significant effect in homozygous mice. Intraventricular administration of DPDPE also reduced the frequency of paw withdrawal (FPW) in wild type mice, but not in homozygous mice. In contrast, systemic U50488H produced a dose-dependent attenuation of paw withdrawal in both wild type and homozygous mice. These findings suggest that (1) interactions of endogenous peptides with mu-opioid receptors may not play a significant role in the response to mechanical stimuli in drug-free animals, and (2) deficiency of mu-opioid receptors has no functional consequence on the response to the prototypical kappa-opioid receptor agonist, but decreases responses to the prototypical mu- and delta-opioid receptor agonists. 相似文献
33.
Edwards DP Mulkern E Raja AN Barker P 《Journal of the Royal College of Surgeons of Edinburgh》1999,44(6):362-365
AIM: Thoracic outlet syndrome (TOS) is a clinical diagnosis treatable by excision of the first rib. This study was undertaken to assess the alleviation of symptoms following trans-axillary rib excision in patients with a diagnosis of TOS suggested by a positive Elevated Arm Stress Test and, by inference, to estimate the prevalence of the syndrome. METHOD: A retrospective review of trans-axillary first rib excision was performed. No referrals were accepted from outwith the catchment area of our hospital. Post-operative symptomatic improvement was accepted as a confirmation of correct pre-operative diagnosis. RESULTS: Over six years, 52 rib resections were performed in 46 patients, mean age (+/- S.D.) 38.8 (+/- 10.6) years. The indications for surgery were principally neurological symptoms (n = 42 excisions), arterial compromise (n = 5) and venous compromise (n = 5). Symptoms had been present for a mean of 15.8 months prior to surgery. The median follow-up after surgery was 33 months. 42 patients (48 resections) showed immediate improvement in symptoms following surgery, although symptoms recurred in three patients (4 resections) between 6 and 8 months post-operatively. In the final two years of this study, 20 resections resulting in symptomatic improvement were performed, suggesting a prevalence for TOS of at least 10 per 100,000 per year. CONCLUSIONS: Thoracic outlet decompression was performed more frequently in this series than many previous reports, suggesting that TOS may be under-diagnosed. 相似文献
34.
35.
Twenty-seven patients with idiopathic palmoplanter hyperhidrosis were treated with Iontotherapy over a one year period. In twenty-four cases there was a good response but maintenance therapy was required every 3-4 weeks.KEY WORDS: Iontophoresis, Palmoplanter hyperhidrosis 相似文献
36.
37.
Kevin X. Liu Eileen M. Duggan Alyaa Al‐Ibraheemi Raja Shaikh Denise M. Adams 《Pediatric blood & cancer》2019,66(1)
Epithelioid hemangioma (EH) is a rare benign vascular tumor that occurs in soft tissues and bone and presents between the third and sixth decades of life. Little is known about the clinical course and outcomes of pediatric EH. We report 11 patients diagnosed with EH at a median age of 14.4 years. One patient treated with interferon and one with sirolimus exhibited partial response for >2 years. Although a benign neoplasm, EH is difficult to manage without standard protocols and portends considerable morbidity. Our findings suggest medical management, particularly sirolimus, may benefit these patients; however, long‐term follow‐up is needed. 相似文献
38.
39.
Eugen Dhimolea Ricardo de Matos Simoes Dhvanir Kansara Aziz Al’Khafaji Juliette Bouyssou Xiang Weng Shruti Sharma Joseline Raja Pallavi Awate Ryosuke Shirasaki Huihui Tang Brian J. Glassner Zhiyi Liu Dong Gao Jordan Bryan Samantha Bender Jennifer Roth Michal Scheffer Constantine S. Mitsiades 《Cancer cell》2021,39(2):240-256.e11
- Download : Download high-res image (202KB)
- Download : Download full-size image
40.
Jonathan R. Dillman Haley C. Neef Peter F. Ehrlich Raja Rabah Peter J. Strouse 《Pediatric radiology》2012,42(12):1517-1522
There are numerous causes of iron deficiency anemia due to gastrointestinal tract bleeding in children. While a very thorough history may elucidate common etiologies, such as cow’s milk protein-induced colitis and nonsteroidal anti-inflammatory drug-related gastritis or peptic ulcer disease, other less frequent causes often present a diagnostic challenge. We present the MR enterography (MRE), CT and Meckel scan findings of ileal dysgenesis coexisting with multiple enteric duplication cysts in a young child who presented with chronic iron deficiency anemia, recurrent gastrointestinal tract bleeding and unexplained bowel perforation. In this case, MRE was able to identify and characterize each individual lesion and directly guide appropriate surgical management. 相似文献