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   5057篇
  免费   362篇
  国内免费   123篇
耳鼻咽喉   60篇
儿科学   30篇
妇产科学   49篇
基础医学   383篇
口腔科学   199篇
临床医学   522篇
内科学   614篇
皮肤病学   54篇
神经病学   246篇
特种医学   141篇
外国民族医学   2篇
外科学   514篇
综合类   725篇
预防医学   312篇
眼科学   141篇
药学   771篇
  5篇
中国医学   577篇
肿瘤学   197篇
  2024年   27篇
  2023年   101篇
  2022年   246篇
  2021年   345篇
  2020年   266篇
  2019年   273篇
  2018年   223篇
  2017年   210篇
  2016年   194篇
  2015年   181篇
  2014年   370篇
  2013年   349篇
  2012年   298篇
  2011年   350篇
  2010年   255篇
  2009年   213篇
  2008年   231篇
  2007年   187篇
  2006年   171篇
  2005年   159篇
  2004年   146篇
  2003年   130篇
  2002年   80篇
  2001年   58篇
  2000年   58篇
  1999年   35篇
  1998年   32篇
  1997年   36篇
  1996年   34篇
  1995年   13篇
  1994年   25篇
  1993年   19篇
  1992年   10篇
  1991年   14篇
  1990年   14篇
  1989年   23篇
  1988年   10篇
  1987年   13篇
  1986年   9篇
  1985年   34篇
  1984年   18篇
  1983年   16篇
  1982年   23篇
  1981年   14篇
  1980年   11篇
  1979年   6篇
  1978年   5篇
  1977年   2篇
  1976年   3篇
  1973年   1篇
排序方式: 共有5542条查询结果,搜索用时 15 毫秒
101.
102.
目的观察符合条件的慢性化脓性中耳炎患者行Tos改良联合入路清理病变并一期植入钛人工听骨行鼓室成形的效果。方法回顾性分析34例在该院施行Tos改良联合入路乳突开放并植入钛人工听骨行鼓室成形的慢性化脓性中耳炎病例,总结患者手术前后听力及影像学特点,观察手术前后言语频率气导听阈变化。结果以术中听骨破坏情况分组,镫骨板上结构缺失组植入全听骨赝复体(TORP)后听力改善(36.25±6.12)dB HL;砧蹬关节中段组植入部分听骨赝复体(PORP)后听力改善(13.18±3.37)dB HL。术后无钛听骨移位、感染,听力改善有效率97.06%(P0.05)。1~3个月全部干耳。结论 Tos改良联合入路鼓室成形并一期植入钛人工听骨能有效地清理中耳病变,尤其是清理后鼓室的隐匿病变,并有效提高听力,术前高分辨率CT(HRCT)发现乳突气化不良,尤其有乙状窦前移、脑板低位和面神经低位等不利于暴露的解剖变异时,可优先选择此术式。  相似文献   
103.
Background:This meta-analysis was performed to review the effects of the addition of modified ultrafiltration (MUF) and conventional ultrafiltration (CUF) to CUF alone on postoperative hemoglobin, surgical and ultrafiltration data, and postoperative clinical outcomes in pediatric patients undergoing cardiac surgery.Methods:A systematic search was performed to identify randomized controlled clinical trials that compared MUF and CUF combination with CUF alone in pediatric cardiac surgery undergoing cardiopulmonary bypass (CPB) in PubMed, Embase, Cochrane Library, and Web of Science without any language or date limitation in February 2020. For each included trial, the primary outcomes including post-CPB and postoperative hematocrit, surgical and ultrafiltration data, postoperative clinical outcomes including volume of chest tube drainage within 48 hours after surgery and perioperative blood requirement, ventilation support duration, and length of stay day in the intensive care unit (ICU) and hospital were collected and analyzed. The analysis was conducted using STATA version 12.0.Results:A total of 8 trials encompassing 405 patients were included in this analysis. Analysis indicated that MUF + CUF increased the post-CPB hematocrit (Standard mean difference, SMD = 1.85, 95% confidence interval, 95% CI 0.91–2.79). Meanwhile, ultrafiltration volume was higher in CUF+MUF infants than CUF-alone infants (SMD = 1.46, 95% CI 0.51–2.41, P = .003). The clinical outcomes, including postoperative hemodynamic changes, prime volume, blood requirement, chest tube drainage volume, mechanical ventilation duration, and ICU duration, were unclear because of the unstable sensitivity analyses.Conclusions:Beneficial effects of using MUF and CUF for pediatric cardiac surgery, including increase post-CPB hematocrit and ultrafiltration volume when compared with CUF alone. Meanwhile, MUF and CUF did not significantly influence the postoperative hospital stay duration, CPB, and aortic occlusion duration.  相似文献   
104.

Background

Nanoparticles (NPs) play an important role in anticancer delivery systems. Surface modified NPs with hydrophilic polymers such as human serum albumin (HSA) have long half-life in the blood circulation system.

Methods

The method of modified nanoprecipitation was utilized for encapsulation of paclitaxel (PTX) in poly (lactic-co-glycolic acid) (PLGA). Para-maleimide benzoic hydrazide was conjugated to PLGA for the surface modifications of PLGA NPs, and then HSA was attached on the surface of prepared NPs by maleimide attachment to thiol groups (cysteines) of albumin. The application of HSA provides for the longer blood circulation of stealth NPs due to their escape from reticuloendothelial system (RES). Then the physicochemical properties of NPs like surface morphology, size, zeta potential, and in-vitro drug release were analyzed.

Results

The particle size of NPs ranged from 170 to 190 nm and increased about 20–30 nm after HSA conjugation. The zeta potential was about -6 mV and it decreased further after HSA conjugation. The HSA conjugation in prepared NPs was proved by Fourier transform infrared (FT-IR) spectroscopy, faster degradation of HSA in Differential scanning calorimetry (DSC) characterization, and other evidences such as the increasing in size and the decreasing in zeta potential. The PTX released in a biphasic mode for all colloidal suspensions. A sustained release profile for approximately 33 days was detected after a burst effect of the loaded drug. The in vitro cytotoxicity evaluation also indicated that the HSA NPs are more cytotoxic than plain NPs.

Conclusions

HSA decoration of PLGA NPs may be a suitable method for longer blood circulation of NPs.  相似文献   
105.
目的 探讨蛛网膜下腔出血(subarachnoid hemorrhage,SAH)患者不同分级时血清缺血修饰白蛋白(ischemia modified albumin,IMA)的水平变化及对预后判断的意义.方法 94例SAH患者根据Fisher CT分级分组(1级24例、2级27例、3级22例、4级21例),检测其血清中IMA的水平.结果 Fisher CT分级1级、2级、3级、4级时IMA水平分别为36.47±4.05、42.26±4.67、45.71±4.92、79.63±7.28.SAH患者病情轻型组的IMA和中国临床神经功能缺损评分(CSS积分)分别为37.71±4.14、6.38±3.13;中型组为49.24±5.06、24.76±7.53;重型组为78.33±6.94、42.67±9.25.SAH出院时预后良好组IMA和改良Rankin评分(modified rankin scale,mRS)分别为38.64±4.17、2.85±3.13,预后不良组为60.85±6.01、28.67±8.65.结论 SAH的发病过程中IMA水平明显升高,其水平和SAH的分级和预后有一定关联性,可作为SAH的预后判断指标之一.  相似文献   
106.
Characteristics of dysphagia in children with cerebral palsy   总被引:7,自引:0,他引:7  
Videofluoroscopic modified barium swallow (VMBS) examinations may provide clinically relevant information regarding deglutition in children with cerebral palsy and dysphagia. A retrospective review of clinical evaluations and VMBS studies on 90 consecutive children with cerebral palsy and dysphagia was completed. Most children were referred because of concerns regarding airway protection during oral feedings. Most children had multiple disabilities and 93% were nonambulatory. The majority of children were totally dependent for oral feedings (80%). Oral and pharyngeal phase abnormalities were present in almost all patients. Abnormalities of deglutition were observed only while swallowing specific food textures in the majority of patients. Aspiration of specific food textures was significantly more common than aspiration of all food textures (p<0.0001). Finally, aspiration was silent in 97% of the patients. VMBS studies can provide clinicians with valuable information regarding the most appropriate food textures and rates of oral feeding for children with cerebral palsy and dysphagia.  相似文献   
107.
Acute ischemic stroke is the leading cause of disability and among the leading causes of mortality worldwide. Intravenous tissue plasminogen activator has been a cornerstone for treatment of acute ischemic stroke for more than 20 years; however, its use is limited due to a narrow therapeutic window, several contraindications, and low efficacy to recanalize the artery in large vessel occlusion. Recently, the addition of endovascular mechanical thrombectomy of large artery occlusion has revolutionized the stroke treatment for most disabling strokes. The paper reviews updates to the thrombolytic treatment as well as catheter-based treatment, and results from recent trials in the selection of patients in an extended time window using perfusion imaging.  相似文献   
108.
Introduction: The first gene therapy medicines are licensed and National Institute for Health and Care Excellence approved for use in the NHS. UK Hospital pharmacy departments will need to work with multidisciplinary colleagues to ensure that there are facilities available to handle this new group of medicines.

Areas Covered: UK licensed and National Institute for Health and Care Excellence gene therapy medicinal products (GTMP) and requirements for handling. Review of pharmacy facilities and implementation of advanced therapy medicinal products (ATMP) in the UK.

Expert Opinion: Most hospital pharmacy departments do not have aseptic facilities for the reconstitution of gene therapy medicines, or have the appropriate freezers in place. Staff do not have the understanding or training of these products unless they are experienced in using them in clinical trials. Chief Pharmacists will need to ensure that governance process are in place as they will ultimately be responsible for the implementation and safe handling of these product. Therefore, work needs to continue to highlight the importance of pharmacy departments and their role in the implementation of this new group of medicines. As more GTMPs are licensed and become standard medicines being handled in pharmacy departments, there will be more hospital pharmacy departments ready to handle them. Initially it will just be the centers of excellence, ATMP centers, and research centers with the expertise and facilities. In the long-term, other hospitals will plan and build the facilities they require.  相似文献   

109.
110.

Essentials

  • The role of cerebral venous thrombosis (CVT) recanalization on neurologic outcome is still debated.
  • We studied a large cohort of 508 CVT patients with 419 patient years of radiological follow‐up.
  • Recanalization rate is high during the first months after CVT and neurologic outcome is favorable.
  • High recanalization grade of CVT independently predicts good neurological outcome.

Summary

Background

Studies with limited sample size and with discordant results described the recanalization time‐course of cerebral venous thrombosis (CVT). The neurological outcome after a first episode of CVT is good, but the role of recanalization on neurological dependence is still debated.

Objectives

The aim of the study is to assess the recanalization rate after cerebral venous thrombosis (CVT) and its prognostic role in long‐term neurological outcome.

Patients/Methods

In a retrospective observational multicenter cohort study, patients with an acute first episode of CVT with at least one available imaging test during follow‐up were enrolled. Patency status of the vessels was categorized as complete, partial or not recanalized. Neurological outcome was defined using the modified Rankin scale (mRS) as good (mRS = 0–1) or poor (mRS = 2–6).

Results

Five‐hundred and eight patients (median [IQR] age, 39 [28.5–49] years; 26% male) were included. Complete or partial recanalization was not differently represented in patients undergoing scans at different periods of time (from 28‐day to 3 month‐period up to a 1–3 year‐period). mRS at the time of follow‐up imaging was available in 483 patients; 92.8% of them had a mRS of 0‐1. CVT recanalization (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.59–4.13) was positively associated, whereas cancer (OR, 0.29; 95% CI, 0.09–0.88), and personal history of venous thromboembolism (VTE) (OR, 0.36; 95% CI, 0.14–0.92) were negatively associated as independent predictors of favorable (mRS = 0–1) outcome at follow‐up.

Conclusions

Most patients with a first CVT had complete or partial recanalization at follow‐up. Recanalization was independently associated with a favorable neurological outcome.
  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