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   92638篇
  免费   7040篇
  国内免费   2358篇
耳鼻咽喉   3147篇
儿科学   1019篇
妇产科学   1801篇
基础医学   4138篇
口腔科学   4457篇
临床医学   8193篇
内科学   8708篇
皮肤病学   965篇
神经病学   2913篇
特种医学   1621篇
外国民族医学   22篇
外科学   26885篇
综合类   12923篇
现状与发展   12篇
一般理论   2篇
预防医学   3673篇
眼科学   5643篇
药学   6194篇
  178篇
中国医学   3564篇
肿瘤学   5978篇
  2024年   108篇
  2023年   2303篇
  2022年   2726篇
  2021年   4579篇
  2020年   4737篇
  2019年   4060篇
  2018年   3971篇
  2017年   3527篇
  2016年   3563篇
  2015年   3736篇
  2014年   7008篇
  2013年   6715篇
  2012年   5610篇
  2011年   5926篇
  2010年   4678篇
  2009年   4326篇
  2008年   4139篇
  2007年   4202篇
  2006年   3622篇
  2005年   3225篇
  2004年   2734篇
  2003年   2265篇
  2002年   1810篇
  2001年   1716篇
  2000年   1461篇
  1999年   1345篇
  1998年   1075篇
  1997年   926篇
  1996年   766篇
  1995年   665篇
  1994年   618篇
  1993年   473篇
  1992年   409篇
  1991年   417篇
  1990年   300篇
  1989年   293篇
  1988年   282篇
  1987年   267篇
  1986年   210篇
  1985年   268篇
  1984年   212篇
  1983年   154篇
  1982年   157篇
  1981年   127篇
  1980年   100篇
  1979年   60篇
  1978年   47篇
  1977年   38篇
  1976年   29篇
  1975年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
BackgroundThe extent of pancreatic resection for intraductal papillary mucinous neoplasms (IPMNs) remains an unresolved issue. The study aims at analyzing the prognostic impact of conservative surgery (CS) i.e. of pancreatoduodenectomy or distal pancreatectomy, versus total pancreatectomy (TP), for pancreatic IPMNs.MethodsWe retrospectively analyzed and compared data of patients who had undergone pancreatic resection for IPMNs at our center between November 2007 and April 2019. Patients were divided into two main groups based on the extent of surgery: TP-group and CS-group. Subsequently, the perioperative and the long-term outcomes were compared. Moreover, a sub-group analysis of patients with IPMN alone and patients with malignant IPMN, based on preoperative indications to surgery and post-operative histopathological findings, was also performed.ResultsFifty-three patients were included in the TP-group and 73 in the CS-group. In 50 (39.7%) cases the frozen section changed the pre-operative surgical planning, with an extension of the pancreatic resection, in 43 (34.1%) cases up to a total pancreatectomy. Twenty-six patients (20.6%) with low-grade dysplasia at the frozen section underwent CS, while twenty (15.8%) underwent TP. Comparing these two sub-groups no differences were found in surgical IPMN recurrence, nor progression. The rate of overall postoperative complications was 56.6% in the TP-group and 57.5% in the CS-group (p = 0.940). Fifteen patients (20.5%) developed diabetes in the CS-group.None of the patients treated with CS developed a surgical IPMN recurrence or progression during the follow-up period. Comparing OS and DFS of the two groups, we did not find any statistically significant difference (p = 0.619 and 0.315).ConclusionA timely CS can be considered an appropriate and valid strategy in the surgical treatment of the majority of pancreatic IPMNs, as it can avoid the serious long-term metabolic consequences of TP in patients with a long-life expectancy. On the contrary, TP remains mandatory in case of PDAC or high-risk features involving the entire gland.  相似文献   
42.
43.
《Neuromodulation》2021,24(8):1336-1340
BackgroundThe use of implantable pulse generators (IPG) for spinal cord stimulation (SCS) in patients with chronic pain has been well established. Although IPG-related complications have been reported on, the association between IPG site and SCS complications has not been well studied.ObjectiveTo investigate whether IPG placement site in buttock or flank is associated with SCS complications and, hence, revision surgeries.MethodA retrospective cohort study was performed that included 330 patients (52% female) treated at a single institution who underwent permanent implantation of an SCS system between 2014 and 2018. Patients ranged between 20 and 94 years of age (mean: 57.54 ± 13.25). Statistical analyses were conducted using IBM SPSS Statistics. Tests included independent samples t test, chi-square test, Mann–Whitney U test, Spearman’s rank correlation coefficient, and logistic regression.ResultsThere was a total of 93 revision surgeries (rate of 28%), where 71 out of 330 patients (rate of 21.5%) had had at least one revision surgery. Univariate tests demonstrated a significant association between IPG site and revision surgeries (p = 0.028 [chi-square test] and p = 0.031 [Mann–Whitney U test]); however, multivariate logistic regression demonstrated that neither IPG site was more likely than the other to require revision surgeries (p = 0.286).ConclusionAlthough this study found a significant association between IPG site and revision surgeries, the effect of IPG site was not found to be predictive. The IPG site likely influences whether a patient will require revision surgery, but further investigation is required to establish this association.  相似文献   
44.
45.
46.
47.
48.
胡俊  黄菲  刘丹  阚智勇  杨文庆  徐小琴 《西部医学》2021,32(9):1369-1373
【摘要】 目的 探讨不同剂量羟考酮通过患者硬膜外自控镇痛(PCEA)与患者静脉自控镇痛(PCIA)用于前列腺术后的镇痛效果。 方法 选取在2018年1月~2020年1月期间于我院行前列腺术的210例患者,采用随机数字表法将患者分成A1、A2、A3、B1、B2、B3 6组,每组各35例。其中A1、A2、A3组术后镇痛采用PCIA方案,分别使用0.6mg/kg、0.8mg/kg、1.0mg/kg的羟考酮+托烷司琼10mg+0.9%氯化钠溶液至100mL;B1、B2、B3术后镇痛采取PCEA方案,分别使用0.6mg/kg、0.8mg/kg、1.0mg/kg的羟考酮+托烷司琼10mg+0.9%氯化钠溶液至100mL。比较手术前(T0)、术后6h(T1)、术后12h(T2)、术后24h(T3)及术后48h(T4)6组患者的生命体征、视觉疼痛模拟评分(VAS)及不良反应的发生情况。 结果 各组患者在不同时间点的MAP、HR及SPO2的水平比较差异无统计学意义(P>0.05)。B1、B2、B3组患者分别在T1、T2、T3、T4时间的VAS评分显著低于A1、A2、A3组(均P<0.05),A2、A3组患者分别在T1、T2、T3、T4时间的VAS评分显著低于A1组(均P<0.05),B2、B3组患者分别在T1、T2、T3、T4时间的VAS评分显著低于B1组(均P<0.05)。B1、B2、B3不良反应的发生率分别显著低于A1、A2、A3组(均P<0.05)。B1、B2不良反应的发生率显著低于A2、A3组(P<0.05),且A3组不良反应的发生率显著高于A1、A2,B3组的不良反应的发生率显著高于B1、B2组(均P<0.05)。 结论 对前列腺手术患者术后,不同剂量羟考酮PCEA的镇痛效果及不良反应发生率均显著优于不同剂量羟考酮的PCIA,且当羟考酮的剂量为0.8mg/kg时,效果最佳。  相似文献   
49.
BackgroundWhile recent studies have introduced the composite measure of a textbook outcome (TO) for measuring postoperative outcomes, the incidence of a TO has not been characterized among patients undergoing cytoreductive surgery (CRS) for peritoneal surface malignancies (PSM).Study designAll patients who underwent CRS ± hyperthermic intraperitoneal chemotherapy (HIPEC) between 1999 and 2017 from 12 institutions were included. A TO was defined as the absence of any of the following criteria: completeness of cytoreduction >1, reoperation within 90-days, readmission within 90-days, mortality within 90-days, any grade ≥2 complication, hospital stay >75th percentile, and non-home discharge.ResultsAmong 1904 patients who underwent CRS, only 30.9% achieved a TO while 69.1% failed to achieve a TO most commonly because of postoperative complications. On multivariable analysis, factors associated with achieving a TO were age <65 years (OR: 1.5), albumin ≥3.5 g/dl (OR: 5.7), receipt of HIPEC (OR: 4.5), PCI ≤14 (OR: 2.2), intravenous fluid volume ≤10,000 ml (OR: 2.1), blood loss ≤1000 ml (OR: 4.2) and operative time <7 h (OR: 1.9); while receipt of neoadjuvant therapy (OR: 0.7) and liver resection (OR: 0.4) were associated with not achieving a TO (all p < 0.05). TO was associated with improved overall survival (median 159 months vs 56 months, p < 0.01) even after controlling for confounders on Cox regression (hazard ratio: 2.5, p < 0.01).ConclusionAmong patients undergoing CRS ± HIPEC for PSM, failure to achieve a TO is common and independently associated with worse overall survival.  相似文献   
50.
《Clinical neurophysiology》2021,132(7):1416-1432
ObjectiveNeuromonitoring of primary motor regions allows preservation of motor strength and is frequently employed during cranial procedures. Less is known about protection of sensory function and ability to modulate movements, both of which rely on integrity of thalamocortical afferents (TCA) to fronto-parietal regions. We describe our experience with TCA monitoring and their cortical relays during brain tumor surgery.MethodologyTo study its feasibility and usefulness, continuous somatosensory evoked potentials (SSEP) recording via a subdural electrode was attempted in 32 consecutive patients.ResultsMedian and posterior tibial SSEP were successfully monitored in 31 and 17 patients respectively. SSEP improved lesion localization and prevented unnecessary cortical stimulation in 9 and 16 cases respectively. A threshold of ≥30% SSEP amplitude decrease influenced management in 10 patients while a decrement of ≥50 % had a sensitivity of 0.89 and specificity of 1 in detecting worsening of sensory function. Simultaneous motor evoked potentials (MEP) and SSEP monitoring were performed in 10 cases, 9 of which showed short-lived fluctuations of the former.ConclusionDirect cortical SSEP monitoring is feasible, informs management and predicts outcome.SignificanceEarly intervention prevents sensory deficit. Concomitant MEP fluctuations may reflect modulation of motor activity by TCA.  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