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   7191篇
  免费   439篇
  国内免费   118篇
耳鼻咽喉   123篇
儿科学   115篇
妇产科学   184篇
基础医学   488篇
口腔科学   433篇
临床医学   1133篇
内科学   353篇
皮肤病学   56篇
神经病学   239篇
特种医学   262篇
外国民族医学   1篇
外科学   1687篇
综合类   1068篇
预防医学   442篇
眼科学   445篇
药学   393篇
  12篇
中国医学   156篇
肿瘤学   158篇
  2024年   17篇
  2023年   156篇
  2022年   195篇
  2021年   348篇
  2020年   346篇
  2019年   253篇
  2018年   237篇
  2017年   291篇
  2016年   273篇
  2015年   303篇
  2014年   572篇
  2013年   509篇
  2012年   477篇
  2011年   510篇
  2010年   414篇
  2009年   361篇
  2008年   307篇
  2007年   322篇
  2006年   283篇
  2005年   212篇
  2004年   183篇
  2003年   152篇
  2002年   112篇
  2001年   99篇
  2000年   89篇
  1999年   82篇
  1998年   76篇
  1997年   69篇
  1996年   63篇
  1995年   35篇
  1994年   50篇
  1993年   39篇
  1992年   39篇
  1991年   30篇
  1990年   25篇
  1989年   23篇
  1988年   20篇
  1987年   28篇
  1986年   26篇
  1985年   26篇
  1984年   10篇
  1983年   11篇
  1982年   17篇
  1981年   13篇
  1980年   18篇
  1979年   6篇
  1977年   10篇
  1976年   4篇
  1974年   4篇
  1973年   2篇
排序方式: 共有7748条查询结果,搜索用时 22 毫秒
81.
82.
范晓东  张敬堂  张宏伟 《骨科》2021,12(5):451-455
目的 比较膝关节屈曲90°连续缝合切口和膝关节伸直位连续缝合切口在全膝关节置换术(total knee arthroplasty,TKA)中的应用效果。方法 选择2017年1月至2019年1月我院收治的122例拟行TKA手术的病人,采用随机数字表法将病人分为两组,对照组(61例)采用膝关节伸直位连续缝合切口,观察组(61例)采用膝关节屈曲90°连续缝合切口。比较两组病人切口长度、缝合时间、手术时间、术后失血量、直腿抬高活动时间、屈膝90°活动时间、拆线时间、住院时间、Hollander切口愈合(Hollander wound evaluation scale,HWES)评分、美国纽约特种外科医院(American hospital for special surgery,HSS)膝关节评分、Rasmussen评分、膝关节活动范围(ROM)、疼痛视觉模拟量表(visual analogue scale,VAS)以及术后并发症差异。结果 两组切口长度、缝合时间、手术时间、术后失血量、直腿抬高活动时间、拆线时间、住院时间、HWES评分、并发症发生率比较,差异均无统计学意义(P均>0.05)。观察组屈膝90°活动时间短于对照组,术后24 h、48 h的HSS评分、Rasmussen评分高于对照组,膝关节ROM大于对照组,术后24 h、48 h、72 h的VAS评分均低于对照组,差异均有统计学意义(P均<0.05)。结论 膝关节屈曲90°连续缝合切口可减轻术后早期疼痛程度,利于膝关节功能恢复,且不增加并发症发生风险。  相似文献   
83.
ObjectiveTo compare the clinical efficacy of the direct anterior approach in lateral decubitus position (L‐DAA) and supine position (S‐DAA) for unilateral total hip arthroplasty.MethodsA retrospective study was conducted on 89 patients who underwent primary unilateral total hip arthroplasty in our department between August 2016 and December 2017. There were 46 patients who underwent L‐DAA and 43 patients who underwent S‐DAA. The body mass index (BMI), operation time, blood loss, preoperative Hb, first day and third day postoperative Hb, incision length, hospital stay, preoperative and postoperative Harris score, preoperative and postoperative visual analogue scale (VAS) score, radiological evaluation, intraoperative and postoperative complication, postoperative absolute length difference of lower extremity were recorded and analyzed. P < 0.05 was set as the significant difference.ResultsAll patients were followed up for 8–23 months, with an average of 15.6 months. No significant differences were found in preoperative and postoperative Harris scores, preoperative Hb, incision lengths, radiological evaluations, preoperative and postoperative VAS scores, and hospital stay (P > 0.05). However, significant differences were detected in BMI, blood loss, first day and third day postoperative Hb, and operation time (P < 0.05). There were no postoperative complications in the L‐DAA and S‐DAA groups. During the operation, two cases of proximal femoral fracture occurred in the L‐DAA group, four in the S‐DAA group, and the difference was statistically significant. There were significant differences found in the postoperative absolute length difference of lower extremity between the two groups.ConclusionCompared with the S‐DAA approach, the L‐DAA approach had the advantages of shorter operation time and less blood loss. Compared with S‐DAA, it was easier to expose the proximal femur, and lower BMI was required in L‐DAA. However, it was more difficult to compare the length of both lower extremities in the L‐DAA approach than in the S‐DAA approach.  相似文献   
84.
PurposeCompletely displaced distal radius fractures in children have been traditionally reduced and immobilized with a cast or pin fixed. Cast immobilization leaving the fracture displaced in the bayonet position has been recently suggested as a non-invasive and effective treatment alternative. This is a pilot comparative study between reduction and no reduction.MethodsWe assessed subjective, functional and radiographic outcome after a minimum 2.5-year follow-up in 12 children under ten years of age who had sustained a completely displaced metaphyseal radius fracture, which had been immobilized leaving the fracture in an overriding position (shortening 3 mm to 9 mm). A total of 12 age-matched patients, whose similar fractures were reduced and pin fixed, were chosen for controls. ResultsAt follow-up none of the 24 patients had visible forearm deformity and the maximal angulation in radiographs was 5° Forearm and wrist movement was restored (< 10° of discrepancy) in all 24 patients. Grip strength ratio was normal in all but three surgically treated patients. All patients had returned to their previous activities. One operatively treated boy who was re-operated on reported of pain (visual analogue scale 2).ConclusionThe results of this study do not demonstrate the superiority of reduction and pin fixation over cast immobilization in the bayonet position of closed overriding distal metaphyseal radius fractures in children under ten years with normal neurovascular findings.Level of evidenceIII  相似文献   
85.
BackgroundThis study investigated a comfortable suture angle (CSA) with optimized trocar position for closing the defect during renorrhaphy in retroperitoneal laparoscopic partial nephrectomy (LPN). The feasibility, usefulness, and safety of achieving the CSA with modified trocar position were determined for different tumor types.MethodsTwo optimized trocar positions were introduced for different tumor types. A suture angle was based on the tumor plane of the superficial parenchyma defect and the line formed by the needle holder. Preliminary surgical simulations determined a CSA that combined the least suture time with the greatest ease of performance. Achieving the CSA was attempted during renorrhaphy of 106 enrolled patients undergoing retroperitoneal LPN. Patients’ characteristics, operative features, and follow-up information were collected and analyzed.ResultsFor 89 (83.96%) patients, a CSA was successfully reached and parenchyma recovered. The remaining 17 patients were successfully sutured, but the attempt to achieve a CSA failed. For the CSA group, the suture, clamping, and overall operative times were significantly less than that of the non-CSA patients. The groups were similar regarding estimated blood loss, positive surgical margin, and rates of glomerular filtration reduction and complications. Univariable analyses determined that tumor location, growth pattern, and R.E.N.A.L. nephrometry score (RNS) may influence the success of this approach. Multivariable analyses indicated that only tumor location and RNS were independent factors affecting successful achievement of the CSA.ConclusionsThrough different kidney position changes, the CSA could be used to ease the suture process. It is feasible and safe to perform a CSA with optimized trocar position during LPN. Tumor location and RNS may influence the approach to get a CSA.  相似文献   
86.
探讨DR颈椎斜位影像中应用组织均衡技术的优势   总被引:4,自引:0,他引:4  
目的探讨颈椎斜位直接数字化X线摄影(direct digital radiography,DR)中,采用组织均衡技术的DR图像与标准DR图像的差别。方法利用中国医科大学附属第一医院引进的GE—Revolution XQ/Ⅰ型DR机对所摄的颈椎斜位影像中随机抽取100例作为分析资料。应用组织均衡技术对图像进行处理,同时与标准DR图像进行比较。结果应用组织均衡技术的图像,同一幅图像上不同部位的细节均可清晰显示;标准DR图像需调节不同的窗宽、窗位才能清晰显示或不能显示不同体厚部位的细节。结论在直接数字化X线摄影中,应用组织均衡技术能明显改善因受体厚度影响而难于观察部分的可视性,同时又不牺牲其他部分的细节显示,使DR的应用更完美。  相似文献   
87.
Hypotony with reduced a reduced visual acuity is often seen after trabeculectomy with mitomycine. In this study we describe measures such as reattaching the sleral flap with at least seven nylon sutures and the controlled and delayed use of argon laser suture lysis. With these preventative measures the percentage of hypotonies (IOP 6 mmHg) three months after surgery was reduced from 38 to 15% and chronically reduced visual acuity was reduced from 38 to 5%. With these adaptations in the surgical technique the complication rate of trabeculectomies with mitomycine can be markedly reduced without affecting the mean IOP (10.9 mmHg versus 10.8 mmHg) three months after surgery and the percentage of eyes with IOP 18 mmHg or less without medication (94 versus 91%).  相似文献   
88.
目的:探讨国产吻、缝合器在超低位直肠前切除术中的应用。方法:对27例直肠癌患者行超低位直肠前切除,应用上海产金钟牌缝合器、吻合器,进行结肠-直肠吻合。结果:本组根治性切除25例(92.6%);1例发生吻合口瘘,发生率为3.7%;吻合口狭窄3例,发生率为11.1%,均经保守治疗治愈。结论:合理使用国产缝合器、吻合器可完成超低位直肠癌的保肛手术,可达保肛、根治、降低费用、减少并发症的目的。  相似文献   
89.
目的:探讨如何处理持续性枕后位,以尽可能减少母儿并发症。方法:总结分析了120例持续性枕后位的孕周、胎儿体重、产重长短对分娩方式的影响以及不同分娩方式对母儿的影响。结果:当孕周大于等于40周,胎儿体重大于等于3500g,潜伏期大于8h,活跃期大于4h时,剖宫产率明显增高,持续性枕后位所致的产程延长及手术助产增加了新生儿窒息率和产妇的并发症。结论:对持续性枕后位应正确观察处理各产程,早期诊断,充分估计其阴道分娩的可能性,对不适于阴道分娩者,应果断行剖宫产术,以降低母儿并发症。[  相似文献   
90.
SUMMARY  Previous studies have shown that premature infants may be at risk for hypoxemia and bradycardia when placed in standard car seats. However, the relationship of such breathing abnormalities to sleep state have not been studied. The purpose of the present study was to investigate the effect of car seat positioning on respiratory patterns in preterm infants during sleep and to evaluate their relationship to sleep state. Complete polysomnography, including sleep and breathing parameters, was performed on twenty-eight premature infants. Each infant was randomly assigned to the car seat or prone (crib) position for the first recording period. Following the recording of at least two sleep cycles, the position was reversed. The percentage of active and quiet sleep was calculated and breathing parameters were measured. In the car seat, the infants spent significantly more time in active sleep and less time in quiet sleep than in the prone position, of the respiratory parameters, periodic breathing (PB) was significantly higher in the car seat. The presence of at least one abnormal breathing events (bradycardia, desaturation, PB apnoea) was also significantly higher in the car seat. An analysis of variance (ANOVA) of PB revealed significant sleep-state effect (active vs. quiet sleep), but no significant condition or interaction effects, indicating that PB was more frequent in active sleep regardless of the sleeping condition. It is concluded that increased active sleep in the car seat condition, rather than the positioning of the infant in the seat per se, may account for the increase in periodic breathing and possibly other breathing abnormalities reported in car seats.  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