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   23137篇
  免费   1370篇
  国内免费   800篇
耳鼻咽喉   114篇
儿科学   310篇
妇产科学   191篇
基础医学   1265篇
口腔科学   212篇
临床医学   1713篇
内科学   2683篇
皮肤病学   88篇
神经病学   528篇
特种医学   439篇
外国民族医学   2篇
外科学   6710篇
综合类   2530篇
现状与发展   1篇
预防医学   2074篇
眼科学   114篇
药学   3293篇
  21篇
中国医学   2504篇
肿瘤学   515篇
  2024年   38篇
  2023年   586篇
  2022年   755篇
  2021年   1371篇
  2020年   1263篇
  2019年   1085篇
  2018年   1204篇
  2017年   1170篇
  2016年   776篇
  2015年   747篇
  2014年   1678篇
  2013年   1922篇
  2012年   1411篇
  2011年   1557篇
  2010年   1091篇
  2009年   954篇
  2008年   990篇
  2007年   955篇
  2006年   738篇
  2005年   596篇
  2004年   456篇
  2003年   421篇
  2002年   364篇
  2001年   300篇
  2000年   263篇
  1999年   273篇
  1998年   198篇
  1997年   193篇
  1996年   172篇
  1995年   191篇
  1994年   143篇
  1993年   122篇
  1992年   126篇
  1991年   110篇
  1990年   87篇
  1989年   76篇
  1988年   82篇
  1987年   66篇
  1986年   63篇
  1985年   121篇
  1984年   93篇
  1983年   60篇
  1982年   77篇
  1981年   71篇
  1980年   59篇
  1979年   50篇
  1978年   38篇
  1977年   33篇
  1976年   40篇
  1975年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
目的 分析参加经肛全直肠系膜切除(taTME)结构化培训尸体手术训练中学员表现。方法 针对2018年4月至2019年7月参加taTME结构化培训研讨会的学员,通过问卷调查获取数据,分析学员在尸体手术训练过程中各步骤的技术表现、术中困难及并发症以及术后标本直肠系膜完整度等结果。结果 共45名学员参加taTME结构化培训研讨会,其中39名学员返回问卷。荷包缝合方面,5名(12.8%)学员未能独立完成,7名(17.9%)学员需要经过两次或以上尝试来完成荷包缝合。在各方向直肠系膜间隙的切开分离过程中,85%~90%学员能在教员不同程度上的口头指导下亲自完成。最终标本直肠系膜完整性的评价中,系膜不完整的标本共5例(12.8%),系膜近乎完整的标本共18例(46.2%),系膜完整的标本共16例(41.0%)。术中并发症及遇到困难方面,18名(46.2%)学员进入错误间隙,1名(2.6%)学员出现直肠穿孔,4名(10.3%)学员出现荷包失败,2名(5.1%)学员出现尿道损伤。单因素分析发现只有学员培训前独立完成taTME手术的例数≥1例为术中不出现并发症的影响因素。结论 参加培训的学员在荷包缝合、直肠全层切开以及直肠系膜间隙的分离等各重要手术步骤中获得较为充足的亲自上手练习机会,较丰富的工作经验以及腹腔镜全直肠系膜切除术(TME),经肛门内镜微创手术(TEM)、经肛门微创手术(TAMIS)的手术经验并不能降低taTME手术经肛操作部分的术中并发症发生率。参加包含尸体手术训练的taTME结构化培训有助于降低术中并发症发生率并提高手术安全性。  相似文献   
22.

Objectives

Short successive periods of skeletal muscle disuse have been suggested to substantially contribute to the observed loss of skeletal muscle mass over the life span. Hospitalization of older individuals due to acute illness, injury, or major surgery generally results in a mean hospital stay of 5 to 7 days, during which the level of physical activity is strongly reduced. We hypothesized that hospitalization following elective total hip arthroplasty is accompanied by substantial leg muscle atrophy in older men and women.

Design and participants

Twenty-six older patients (75 ± 1 years) undergoing elective total hip arthroplasty participated in this observational study.

Measurements

On hospital admission and on the day of discharge, computed tomographic (CT) scans were performed to assess muscle cross-sectional area (CSA) of both legs. During surgery and on the day of hospital discharge, a skeletal muscle biopsy was taken from the m. vastus lateralis of the operated leg to assess muscle fiber type–specific CSA.

Results

An average of 5.6 ± 0.3 days of hospitalization resulted in a significant decline in quadriceps (?3.4% ± 1.0%) and thigh muscle CSA (?4.2% ± 1.1%) in the nonoperated leg (P < .05). Edema resulted in a 10.3% ± 1.7% increase in leg CSA in the operated leg (P < .05). At hospital admission, muscle fiber CSA was smaller in the type II vs type I fibers (3326 ± 253 μm2 vs 4075 ± 279 μm2, respectively; P < .05). During hospitalization, type I and II muscle fiber CSA tended to increase, likely due to edema in the operated leg (P = .10).

Conclusions

Six days of hospitalization following elective total hip arthroplasty leads to substantial leg muscle atrophy in older patients. Effective intervention strategies are warranted to prevent the loss of muscle mass induced by short periods of muscle disuse during hospitalization.  相似文献   
23.
《The Journal of arthroplasty》2020,35(8):2200-2203
BackgroundRecently, a revised definition of the minor criteria scoring system for diagnosing periprosthetic joint infection (PJI) was developed by the second International Consensus Meeting on musculoskeletal infection. The new system combines preoperative and intraoperative findings, reportedly achieving high sensitivity and specificity. We aimed to validate the modified scoring system at a high-volume center.MethodsWe retrospectively reviewed patients who underwent a revision total hip or knee arthroplasty at our institution from May 2015 to August 2018. Serum C-reactive protein, synovial white blood cell count and polymorphonuclear percentage, leukocyte esterase test, alpha-defensin, microbiological and histologic results, and documented existence of sinus tract and intraoperative purulence were available for all patients. Cases with at least 1 major criterion were considered as infected. Using the new minor criteria, a score of ≥6 reflects PJI, while a score <3 can be considered as noninfected. Sensitivity, specificity, mean accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) were analyzed.ResultsA total of 345 cases were included. A cutoff score of ≥6 points had the following diagnostic performance: area under the curve (AUC) = 0.90; ACC = 0.88; sensitivity = 0.96; specificity = 0.84; PPV = 0.70; NPV = 0.98. Diagnostic performance was better for the hip (AUC = 0.92; ACC = 0.90; sensitivity = 0.96; specificity = 0.86; PPV = 0.81; NPV = 0.98) than the knee (AUC = 0.89; ACC = 0.85; sensitivity = 0.95; specificity = 0.83; PPV = 0.59; NPV = 0.98).ConclusionThe modified scoring system proposed by the 2018 International Consensus Meeting in diagnosing PJI showed high sensitivity and a good performance, especially as rule-out diagnostic criteria. The cutoff level seems to be different between the hip and knee. Further validation studies considering the acknowledged limitations are recommended.  相似文献   
24.
随着科学技术的进步和对疾病本身认识的深入,直肠癌的外科治疗从局部切除到全直肠系膜切除(TME),从开放手术到腹腔镜手术,再从腹腔镜手术到机器人手术,目前已经进入微创时代。在此时代背景下,经肛门全直肠系膜切除(TaTME) 应运而生。正如TME的提出者Heald所言:“TaTME是近30年直肠癌外科治疗技术的集大成者”,其发展的每一个阶段都有很强的代表性,已成为直肠癌微创外科治疗技术进步发展的一个缩影。  相似文献   
25.
《The Journal of arthroplasty》2022,37(7):1338-1347
BackgroundMultimodal pain therapy combining analgesics, local infiltration analgesia (LIA) and peripheral nerve blocks, such as fascia iliaca compartment block (FICB), can improve postoperative pain, nausea and vomiting (PONV) and ambulation in patients undergoing total hip arthroplasty (THA). We hypothesized that addition of FICB would decrease opioid requirements and length of stay (LOS) but could create a motor block.MethodsThis is a single center, prospective, blinded randomized controlled study of 152 patients undergoing elective THA via direct anterior approach from October 2019 till August 2021. Three patient groups were defined: patients receiving only spinal anesthesia (control group, n = 53); spinal anesthesia with LIA perioperatively (n = 50); and spinal anesthesia with FICB on the recovery unit (n = 49). Outcome measures consisted of postoperative pain scores, PONV, length of hospital stay, opioid requirements and mobility.ResultsOverall pain scores were low for all patient groups, with a lower pain score for LIA in comparison to the control group until 4 hours postoperatively (P < .05). Length of hospital stay, postoperative pain, nausea and vomiting (PONV) scores and quadriceps muscle strength did not differ significantly between groups. The control group showed higher scores at 12 hours postoperatively in comparison to FICB regarding rehabilitation potential, use of walking aids and activities of daily living (P < .05), but all groups reached the same endpoint 48 hours postoperatively. The LIA and FICB groups required less opioids until 24 hours postoperatively.ConclusionLIA is a beneficial adjuvant therapy to spinal anesthesia in THA patients as it may decrease pain scores and the need for opioid consumption. Adjuvant FICB only provided lower opioid requirements.  相似文献   
26.
BackgroundConsiderable practice variability exists among orthopedic surgeons performing total knee arthroplasty (TKA). The purpose of this study is to understand what TKA surgical and perioperative techniques are standard among high-volume academic knee arthroplasty surgeons.MethodsA written survey with 59 questions regarding management preferences in TKA was distributed by the 2018 John N. Insall Traveling Fellows to all arthroplasty-trained attending physicians at 13 medical centers, with 45 responses recorded.ResultsSurveyed surgeons performed unicompartmental knee arthroplasty (88%) and bilateral TKA (87%). Most surveyed surgeons rarely or never performed outpatient primary TKA (71%). Conventional alignment guides and cemented implants were used by 80% of respondents. Most surgeons used posterior-stabilized implants (67%), followed by cruciate-retaining (20%), ultracongruent (20%), and medial congruent or medial pivot designs (17.8%). Surveyed surgeons frequently or always resurfaced the patella (73%), used a tourniquet for the entire case (73%), and used tranexamic acid for all TKAs (91%). The most common locations for intra-articular anesthetic injection were the arthrotomy (91%), the periosteum (84%), and the medial posterior capsule (82%). Saline (62%) and dilute iodine (47%) were the most common irrigation fluids. The arthrotomy was most commonly closed with running barbed suture (60%) followed by interrupted vicryl (40%). Skin closure was predominantly with running monocryl (60%) followed by staples (29%). Anticoagulation for TKA was primarily aspirin 81 mg BID (60%).ConclusionThere was considerable variability among surgeons polled although a strong preference for more conventional and less developmental techniques prevailed.  相似文献   
27.
28.
29.
《The Journal of arthroplasty》2022,37(10):1922-1927.e2
BackgroundRegional nerve blocks may be used as a component of a multimodal analgesic protocol to manage postoperative pain after primary total hip arthroplasty (THA). The purpose of our study was to evaluate the efficacy and safety of regional nerve blocks after THA in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management.MethodsWe searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published prior to March 24, 2020 on fascia iliaca, lumbar plexus, and quadratus lumborum blocks in primary THA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of the regional nerve blocks.ResultsAn initial critical appraisal of 3,382 publications yielded 11 publications representing the best available evidence for an analysis. Fascia iliaca, lumbar plexus, and quadratus lumborum blocks demonstrate the ability to reduce postoperative pain and opioid consumption. Among the available comparisons, no difference was noted between a regional nerve block or local periarticular anesthetic infiltration regarding postoperative pain and opioid consumption.ConclusionLocal periarticular anesthetic infiltration should be considered prior to a regional nerve block due to concerns over the safety and cost of regional nerve blocks. If a regional nerve block is used in primary THA, a fascia iliaca block is preferred over other blocks due to the differences in technical demands and risks associated with the alternative regional nerve blocks.  相似文献   
30.
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