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   23675篇
  免费   1399篇
  国内免费   644篇
耳鼻咽喉   228篇
儿科学   404篇
妇产科学   1827篇
基础医学   1733篇
口腔科学   524篇
临床医学   3165篇
内科学   4110篇
皮肤病学   83篇
神经病学   1740篇
特种医学   1063篇
外国民族医学   5篇
外科学   2051篇
综合类   3534篇
预防医学   1346篇
眼科学   61篇
药学   1906篇
  50篇
中国医学   1142篇
肿瘤学   746篇
  2024年   19篇
  2023年   401篇
  2022年   682篇
  2021年   1031篇
  2020年   1021篇
  2019年   950篇
  2018年   927篇
  2017年   920篇
  2016年   969篇
  2015年   859篇
  2014年   1787篇
  2013年   1998篇
  2012年   1502篇
  2011年   1667篇
  2010年   1243篇
  2009年   1228篇
  2008年   1137篇
  2007年   1078篇
  2006年   993篇
  2005年   850篇
  2004年   659篇
  2003年   534篇
  2002年   484篇
  2001年   359篇
  2000年   328篇
  1999年   279篇
  1998年   223篇
  1997年   186篇
  1996年   169篇
  1995年   167篇
  1994年   122篇
  1993年   99篇
  1992年   101篇
  1991年   88篇
  1990年   84篇
  1989年   65篇
  1988年   72篇
  1987年   43篇
  1986年   35篇
  1985年   52篇
  1984年   41篇
  1983年   50篇
  1982年   39篇
  1981年   31篇
  1980年   27篇
  1979年   14篇
  1978年   31篇
  1977年   23篇
  1976年   13篇
  1975年   11篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
IntroductionThe Modena bleeding score is a categorical rating scale that allows the assessment of the surgical field in relation to bleeding during endoscopic surgery. It has recently been presented and validated in the field of endoscopic ear surgery by the present authors. The Modena bleeding score provides five grades for rating the surgical field during endoscopic procedures (from grade 1 ? no bleeding to grade 5 ? bleeding that prevents every surgical procedure except those dedicated to bleeding control).ObjectiveThe aim of this study was to validate the Modena bleeding score in the setting of endoscopic sinus surgery.MethodsFifteen three-minute videos of endoscopic sinus surgery procedures (each containing three bleeding situations) were evaluated by 15 specialists, using the Modena bleeding score. Intra and inter-rater reliability were assessed, and the clinical validity of the Modena bleeding score was calculated using a referent standard.ResultsThe data analysis showed an intra-rater reliability ranging from 0.6336 to 0.861. The inter-rater reliability ranged from 0.676 to 0.844. The clinical validity was α = 0.70; confidence limits: 0.64 ? 0.75, corresponding to substantial agreement.ConclusionThe Modena bleeding score is an effective method to score bleeding during endoscopic sinus surgery. Its application in future research could facilitate the performance and efficacy assessment of surgical techniques, materials or devices aimed to bleeding control during endoscopic sinus surgery.  相似文献   
2.
目的 建立妊娠11~13+6周子宫动脉多普勒参数在低危人群中的正常参考值,同时评估其对不良妊娠结局的预测价值。方法 收集2019年6月至2021年6月于我院行产前超声检查的妊娠11~13+6周孕妇,根据妊娠结局分组。收集两侧子宫动脉多普勒指标,包括搏动指数(PI)、阻力指数(RI)、舒张早期是否有切迹,以及孕妇基本临床资料和胎儿出生信息,将以上相关参数进行统计学分析。结果 最终纳入800例孕妇,包括正常妊娠结局组740例和不良妊娠结局组60例。两组孕妇体质量指数(BMI)、分娩孕周和胎儿出生体质量比较,差异均有统计学意义(均P<0.05)。随着孕周的增加,子宫动脉两侧平均搏动指数(mPI)、平均阻力指数(mRI)和两侧舒张早期切迹检出率均呈逐渐下降的趋势。ROC曲线分析显示,mPI、mRI及两侧舒张早期切迹预测妊娠结局的曲线下面积(AUC)分别为0.542、0.574、0.521,三者联合预测妊娠结局的AUC为0.648;孕妇BMI、年龄mPI、mRI及两侧舒张早期切迹预测妊娠结局的AUC为0.751。结论 建立了低危人群在妊娠11~13+6周子宫动脉多普勒参数的正常参考值范围。在妊娠11~13+6周单纯应用子宫动脉多普勒参数预测妊娠结局的价值有限,将子宫动脉参数与临床相关指标结合可提高对不良妊娠结局的预测价值。  相似文献   
3.
PurposeThe aim of this study was to compare catheter angiography (CA) and colonoscopy outcomes after successful CT angiographic (CTA) localization for patients with overt lower gastrointestinal bleeding (LGIB).MethodsSeventy-one consecutive patients from two institutions between 2010 and 2020 had both contrast extravasation on CTA imaging in the lower gastrointestinal tract and subsequent CA or colonoscopy. The primary outcome was confirmation of active bleeding during CA or colonoscopy (defined as confirmation yield). The secondary outcomes were to determine therapeutic yield (hemostatic therapy), time to procedure, rebleeding rate, and adverse outcome rates (defined as surgery, acute kidney injury, initiation of dialysis, and overall mortality). Univariate analyses and multivariable analyses with P < .05 were used to determine statistical significance.ResultsForty-four patients underwent CA and 27 underwent colonoscopy. CA had higher overall confirmation yield (55% vs 26%, P = .026), whereas therapeutic yields were similar (70% vs 56%, P = .214). Time to procedure was 5.1 ± 3.4 hours for CA and 15.5 ± 13.6 hours for colonoscopy (P < .001). On multivariable analysis, shorter time to procedure was the only statistically significant predictor of confirmation yield (P = .037) and therapeutic yield (P = .013), whereas procedure, hemoglobin, transfusions, and hemodynamic instability were not. Adverse events and rebleeding were not statistically different between patients who underwent CA and colonoscopy (P > .05).ConclusionsShorter time to procedure was the only statistically significant predictor of confirmation and therapeutic yield after CTA localization of LGIB. Because CA can be performed sooner than colonoscopy without increased rates of adverse outcomes or rebleeding, CA may be a reasonable first-line treatment option in patients with CTA localization of LGIB.  相似文献   
4.
5.
6.
We report a rare case of uterine carcinosarcoma involving a 74-year-old woman. The patient complained of posmenopausal bleeding. The disease was eventually diagnosed as simultaneous uterine carcinosarcoma and high-grade serous tubal carcinoma.Clinical examination found a cervical tumour and transvaginal ultrasound showed a heterogeneous intrauterine image. The histological result of both findings was carcinosarcoma.The computed tomography scan and magnetic resonance imaging reported similar findings for intrauterine and cervical tumour, with the same features as a possible myoma or mass with sarcomatous degeneration.Given the suspicion of a high-risk variant of endometrial adenocarcinoma, the primary management of carcinosarcoma is surgery. Complete surgical staging included total hysterectomy, bilateral salpingo-oophorectomy, omentectomy, pelvic and para-aortic lymph node dissection.The pathological findings revealed a uterine carcinosarcoma tumour, invading less than half the myometrium and the stromal connective tissue of the cervix but not extending beyond the uterus. The histopathological studies of bilateral adnexectomy and the peritoneal biopsy demonstrated the presence of high-grade serous tubal carcinoma. The lymph study was negative for malignancy.We concluded a synchronous diagnosis of uterine carcinosarcoma stage II and high-grade serous tubal carcinoma stage IIIB.A detailed literature search and management of this entity are discussed.  相似文献   
7.
8.
9.
BackgroundAnterior cruciate ligament (ACL) reconstruction is recommended in patients who intend to return to high-level sports. However, there is only a 55–80% return to pre-injury level of sports after ACL reconstruction, with a re-injury rate up to 20%. The aim of this study was to determine the percentage of patients passing the Back in Action (BIA) test 9 months after primary bone-patellar-tendon-bone (BPTB) ACL reconstruction, and evaluate the association between passing the BIA test and patient reported outcome measurements (PROMs).MethodsPatients underwent the BIA test 9 months after BPTB ACL reconstruction. In total 103 patients were included. Passing the BIA test (PASSED-group) was defined as a normal or higher score at all sub-tests with limb symmetry index (LSI) ≥90% for the dominant leg and LSI >80% for the non-dominant leg. Patients who did not meet these criteria were defined as the FAILED-group. PROMs included the International Knee Documentation Committee, Knee injury Osteoarthritis Outcome Score and Anterior Cruciate Ligament-Return to Sport after Injury.ResultsEighteen patients (17.5%) passed the BIA test 9 months after BPTB ACL reconstruction. PROMs were not statistically significant different between the PASSED- and FAILED-group.ConclusionLow percentage of patients passed the BIA test 9 months after BPTB ACL reconstruction. Although current PROMs cut-off values were met, the BIA test results show persistent functional deficits. Therefore, the BIA test could be of additional value in the decision-making process regarding return to sport (RTS). This study highlights the need for additional rehabilitation as RTS in a condition of incomplete recovery may increase the risk of re-injury.Level of evidenceII.  相似文献   
10.
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