首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   46810篇
  免费   2386篇
  国内免费   2333篇
耳鼻咽喉   47篇
儿科学   434篇
妇产科学   167篇
基础医学   5332篇
口腔科学   1299篇
临床医学   5022篇
内科学   1681篇
皮肤病学   139篇
神经病学   1529篇
特种医学   2924篇
外国民族医学   8篇
外科学   22697篇
综合类   5463篇
现状与发展   2篇
一般理论   1篇
预防医学   864篇
眼科学   57篇
药学   1857篇
  48篇
中国医学   705篇
肿瘤学   1253篇
  2024年   72篇
  2023年   1705篇
  2022年   2898篇
  2021年   3038篇
  2020年   3333篇
  2019年   1828篇
  2018年   1622篇
  2017年   1434篇
  2016年   1663篇
  2015年   2067篇
  2014年   3991篇
  2013年   3348篇
  2012年   3960篇
  2011年   3718篇
  2010年   2280篇
  2009年   1779篇
  2008年   1365篇
  2007年   1472篇
  2006年   1366篇
  2005年   992篇
  2004年   937篇
  2003年   818篇
  2002年   748篇
  2001年   647篇
  2000年   545篇
  1999年   555篇
  1998年   309篇
  1997年   272篇
  1996年   212篇
  1995年   194篇
  1994年   220篇
  1993年   185篇
  1992年   305篇
  1991年   313篇
  1990年   330篇
  1989年   319篇
  1988年   256篇
  1987年   156篇
  1986年   60篇
  1985年   52篇
  1984年   24篇
  1983年   23篇
  1982年   15篇
  1981年   16篇
  1980年   14篇
  1979年   15篇
  1978年   15篇
  1977年   8篇
  1976年   5篇
  1975年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
《The spine journal》2020,20(10):1602-1609
BACKGROUNDSurgical site infections are a major driver of morbidity and increased costs in the postoperative period after spine surgery. Current tools for surveillance of these adverse events rely on prospective clinical tracking, manual retrospective chart review, or administrative procedural and diagnosis codes.PURPOSEThe purpose of this study was to develop natural language processing (NLP) algorithms for automated reporting of postoperative wound infection requiring reoperation after lumbar discectomy.PATIENT SAMPLEAdult patients undergoing discectomy at two academic and three community medical centers between January 1, 2000 and July 31, 2019 for lumbar disc herniation.OUTCOME MEASURESReoperation for wound infection within 90 days after surgeryMETHODSFree-text notes of patients who underwent surgery from January 1, 2000 to December 31, 2015 were used for algorithm training. Free-text notes of patients who underwent surgery after January 1, 2016 were used for algorithm testing. Manual chart review was used to label which patients had reoperation for wound infection. An extreme gradient-boosting NLP algorithm was developed to detect reoperation for postoperative wound infection.RESULTSOverall, 5,860 patients were included in this study and 62 (1.1%) had a reoperation for wound infection. In patients who underwent surgery after January 1, 2016 (n=1,377), the NLP algorithm detected 15 of the 16 patients (sensitivity=0.94) who had reoperation for infection. In comparison, current procedural terminology and international classification of disease codes detected 12 of these 16 patients (sensitivity=0.75). At a threshold of 0.05, the NLP algorithm had positive predictive value of 0.83 and F1-score of 0.88.CONCLUSIONTemporal validation of the algorithm developed in this study demonstrates a proof-of-concept application of NLP for automated reporting of adverse events after spine surgery. Adapting this methodology for other procedures and outcomes in spine and orthopedics has the potential to dramatically improve and automatize quality and safety reporting.  相似文献   
33.
《Foot and Ankle Surgery》2020,26(2):193-197
BackgroundThe aim of this study was to compare the radiographic and functional results between fixation and non-fixation in the Cotton osteotomy for the treatment of adult acquired flatfoot.MethodsA retrospective, case-controlled study of consecutive stage IIB posterior tibial tendon dysfunction (PTTD) patients treated with the same bony reconstructive surgery including cotton osteotomy between 2013 and 2017. Meary’s angle, the medial arch sag angle (MASA), and medial cuneiform cobb angle (MCCA) were evaluated pre-operation, at first weight bearing after surgery, and 12 months post operation.ResultsForty feet were included in the study. The cotton osteotomy utilized screw fixation (n = 20) or non-fixation technique (n = 20). No significant differences between groups were found in pre-operative and follow-up radiographic parameters, union rate, and functional results.ConclusionThe non-fixation with press fit technique is a reliable procedure for Cotton osteotomy and as effective as screw fixation.Level of evidenceLevel III, case control study  相似文献   
34.
《Arthroscopy》2020,36(4):1083-1085
When considering repair of the meniscal cartilages of the knee, the indications for repair must be carefully considered. The morphology of the tear, the zone of injury, and likely vascularity have an impact on patient selection. Patient factors, chronicity of tear, medial or lateral tear, and tear complexity all have a bearing on whether to repair or resect and how best to achieve stable repair. The consequences of meniscectomy are well established, and meniscal tissue resection comes at a cost. The success rates of meniscal cartilage repair are greater when performed in conjunction with anterior cruciate ligament reconstruction. Patient outcomes are better for anterior cruciate ligament reconstruction when performed with meniscal repair than when partial meniscectomy is performed. The optimal configuration of sutures, the suture material used, and the type of suture technique are all important considerations. The focus of this commentary is on the use of absorbable versus nonabsorbable suture material.  相似文献   
35.
36.
37.
《The Journal of arthroplasty》2022,37(11):2257-2261
BackgroundDuring aseptic revision total joint arthroplasty (TJA), one or more cultures may occasionally isolate an organism. The hypothesis of this study was that in a portion of patients undergoing revision arthroplasty for aseptic failure, culture may isolate an organism(s) that can be left untreated.MethodsAll patients undergoing revision TJA from 2000 to 2017 at two institutions were retrospectively reviewed. Patients were categorized as aseptic if they were appropriately investigated preoperatively and did not meet the 2018 International Consensus Meeting criteria. In the aseptic revision cohort, patients with a single positive culture or multiple cultures positive for different organisms (“organism-positive”) and patients who had negative intraoperative cultures (“organism-negative”) were compared based on demographics, comorbidities, operative details, subsequent reoperations, and periprosthetic joint infection (PJI).ResultsIn total, 3,234 International Consensus Meeting–negative aseptic revision TJAs were included, of which 215 patients (6.6%) were organism-positive, 196 (91.2%) had a single positive culture, and 19 (8.8%) were positive for 2 or more distinct organisms (ie, polymicrobial). The most prevalent organisms were coagulase-negative Staphylococci (37.5%), Staphylococcus epidermidis (9.6%), and Cutibacterium acnes (8.0%). Demographics and operative details were comparable between the groups. Using multiple regressions there was no association between culture positivity and the rate of reoperation or PJI.ConclusionIsolation of organisms by culture in patients undergoing revision for aseptic failure was not uncommon. As long as these patients were appropriately investigated preoperatively and PJI was excluded, these findings suggest that culture results may be ignored without subjecting patients to additional antimicrobial treatment.  相似文献   
38.
Hepatocellular carcinoma (HCC) ranks the sixth place of most common cancers. Meanwhile, it is the tertiary mortality cause of cancer. There is no effective therapeutic method to prevent and treat the liver cancer. Sinomenine is a kind of Chinese traditional medicine herbal, it is reported that it can inhibit the viability of several cancer cells. The study is to explore whether sinomenine is also able to inhibit the cell viability of HCC and its potential mechanism. The IC50 of sinomenine in BEL-7402 cells was 5.351 mmol/L, and the IC50 of sinomenine in SMMC-7721 cells was 6.204 mmol/L. The gene expression results showed the relative expression of FGF2, CCND2, DCN, F3, MMP7, NRG1, HMGB1, TRIM29, HAS2, EHF, CTGF, PLK2 were down-regulated, and the relative expression of VEGF A, CITED2, NUPR1, DDX58, IRF9, NAMPT, MMP1, NDRG1, HMGA2, PPARGC1A, IFIT2, PARP9, HEY1, LOX, ETV1, ISG15, BACH, CYLD were up-regulated. Moreover, the IPA analysis results suggested that IFIT3, IFIT1, OAS1, MX1, IRF9, IFI6, IFITM1, ISG15 were up-regulated in BEL-7402 cells treated with sinomenine by activating IFNA2. The findings presented in this study may provide a promising method for the prevention and treatment of liver cancer.  相似文献   
39.
《Injury》2022,53(2):784-788
Intra-articular impacted fragment (IAIF) was considered as the articular surface fragment resulting from impact and compressive forces. Malreduction of IAIF in posterior malleolar fractures was associated with the cause of talus subluxation and long-term arthritis. The effect of IAIF on ankle pressure and stress has not been studied, and it's difficult to do this in cadaver bone. So we established IAIF defect finite element model in posterior malleolar fractures and explored the effect of IAIF defect in ankle joint. We also discussed the relation between IAIF defect and post-traumatic arthritis.  相似文献   
40.
《The spine journal》2022,22(4):660-676
BACKGROUND CONTEXTPrevious studies have proposed that there is a relationship between low back pain (LBP) and morphology and composition of paraspinal muscles. However, results have been conflicting, especially regarding fatty infiltration of muscles.PURPOSEThe primary goal of this study was to review and analyze results from imaging studies which investigated morphological and composition changes in the multifidus, erector spinae and psoas major muscles in people with LBP.STUDY DESIGN/SETTINGSystematic review with meta-analysis.PATIENT SAMPLEA patient sample was not requiredOUTCOME MEASURESThis review did not have outcome measures.METHODSPubMed, Scopus, Web of Sciences, EMBASE and ProQuest were searched for eligible studies up to 31st July 2020 (all languages). A systematic search of electronic databases was conducted to identify studies investigating the association between the morphology and fat content of lumbar muscles in people with LBP compared with a (no LBP) control group. 13,795 articles were identified. Based on the screening for inclusion/ exclusion, 25 were included. The quality of the studies was evaluated using the Newcastle-Ottawa Scale. From the 25 articles, 20 were included in the meta-analysis.RESULTSResults showed that the total cross-sectional area of the multifidus was smaller in people with LBP (Standardized mean difference, SMD = -0.24, 95% CI = -0.5 to 0.03). Combined SMDs showed a medium effect of LBP on increasing multifidus muscle fat infiltration (SMD = 0.61, 95% CI = 0.30 to 0.91). There were no LBP related differences identified in the morphology or composition of the lumbar erector spine and psoas major muscles.CONCLUSIONSPeople with LBP were found to have somewhat smaller multifidus muscles with a significant amount of intramuscular fat infiltration. Varying sample size, age and BMI of participants, quality of studies and the procedures used to measure fat infiltration are possible reasons for inconsistencies in results of previous studies.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号