全文获取类型
收费全文 | 8618篇 |
免费 | 567篇 |
国内免费 | 263篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 90篇 |
妇产科学 | 50篇 |
基础医学 | 870篇 |
口腔科学 | 77篇 |
临床医学 | 1062篇 |
内科学 | 568篇 |
皮肤病学 | 30篇 |
神经病学 | 539篇 |
特种医学 | 613篇 |
外国民族医学 | 1篇 |
外科学 | 2625篇 |
综合类 | 1342篇 |
现状与发展 | 1篇 |
预防医学 | 273篇 |
眼科学 | 40篇 |
药学 | 529篇 |
16篇 | |
中国医学 | 423篇 |
肿瘤学 | 219篇 |
出版年
2024年 | 32篇 |
2023年 | 116篇 |
2022年 | 306篇 |
2021年 | 365篇 |
2020年 | 325篇 |
2019年 | 264篇 |
2018年 | 246篇 |
2017年 | 314篇 |
2016年 | 361篇 |
2015年 | 329篇 |
2014年 | 680篇 |
2013年 | 713篇 |
2012年 | 630篇 |
2011年 | 565篇 |
2010年 | 455篇 |
2009年 | 402篇 |
2008年 | 370篇 |
2007年 | 371篇 |
2006年 | 321篇 |
2005年 | 283篇 |
2004年 | 242篇 |
2003年 | 231篇 |
2002年 | 190篇 |
2001年 | 131篇 |
2000年 | 123篇 |
1999年 | 116篇 |
1998年 | 116篇 |
1997年 | 116篇 |
1996年 | 88篇 |
1995年 | 76篇 |
1994年 | 67篇 |
1993年 | 67篇 |
1992年 | 47篇 |
1991年 | 45篇 |
1990年 | 35篇 |
1989年 | 46篇 |
1988年 | 30篇 |
1987年 | 25篇 |
1986年 | 32篇 |
1985年 | 31篇 |
1984年 | 30篇 |
1983年 | 16篇 |
1982年 | 31篇 |
1981年 | 20篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1975年 | 3篇 |
排序方式: 共有9448条查询结果,搜索用时 31 毫秒
1.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia. 相似文献
2.
This paper describes and analyzes a proposed solution of fundamental limitative factor of teleradiology to overcome the teleradiology usages problems in underdeveloped and developing countries. The goal is to achieve a very simple and cost-efficient way to take advantage of teleradiology in anywhere even in remote and rural areas. To meet the goal of this study, the following methodology which is consists of two main procedures was done: (1) Using a digital camera in order to provide a digital image from radiographs. (2) Using an image compression tool in order to compress digital images. The results showed that there is no significant difference between digital images (non-compress and compress images) and radiographic films. Also, there was a logic relationship between the diagnostic quality and diagnostic accuracy. Since the maximum percent of diagnostic accuracy can be seen among “Good” quality images and the minimum to was related “Poor”. The results of our study indicate that a digital camera could be utilized to capture digital images from radiographic films of chest x-ray. To reduce the size of digital images, a lossy compression technique could be applied at compression percent of 50 or less without any significant differences. The compressed images can be sent easily by email to other places for consultation and also they can be stored with a smaller size. 相似文献
3.
《国际护理科学(英文)》2019,6(3):252-258
ObjectivesThis study aimed to determine the effect of lower leg compression during cesarean section (CS) on post-spinal hypotension (PSH) and neonatal hemodynamic parameters.MethodsThis study is a nonrandomized controlled clinical trial conducted in the cesarean delivery unit of the National Medical institute, Damanhour, Egypt. The sample included 120 parturients (60 intervention and 60 control). The researchers developed three tools for data collection: sociodemographic data and reproductive history interview schedule, electronic monitoring of maternal hemodynamic parameters, and neonatal hemodynamic assessment sheet. All parturients received ordinary pre-operative care. For the intervention group, a long elastic stocking (ordinary pressure 20–30 mmHg, 1 mmHg = 0.133 kPa) was applied on both legs during cesarean section. The control group received the same care without the elastic stocking.ResultsSystolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were significantly higher in the intervention group throughout the entire operation period except in the last 5–15 min. Heart rate was significantly lower in the intervention group. Only 13.3% of the intervention group took ephedrine compared with 45% of the control group. Apgar score was higher among neonates of intervention group compared with the control group at 1 min. Neonatal acidosis was significantly higher in the control group than in the contral group.ConclusionLower leg compression technique can effectively reduce PSH and neonatal acidosis. 相似文献
4.
目的探讨不同剂量骨水泥PKP联合雌激素对绝经后女性骨质疏松性腰椎体压缩性骨折患者的影响。方法选取2015年1月至2018年6月我院收治的120例老年女性骨质疏松性腰椎体压缩性骨折患者为研究对象,按行PKP手术治疗时骨水泥注入的剂量不同分为三组(A组2-4 mL、B组4-5 mL、C组5-6 mL),所有患者均随访1年,比较术后三组患者VAS评分、ODI评分、伤椎椎体前缘高度、椎体中部高度及并发症的发生率。结果三组患者相比,治疗前VAS评分、ODI评分组间比较差异无显著性(P0.05);术后3天及1年后随访时,三组患者各项指标均较治疗前显著改善,组内比较差异具有显著性(P0.05),组间比较差异无显著性(P0.05);治疗前伤椎椎体前缘高度及椎体中部高度组间比较差异无显著性(P0.05);术后3天及1年后随访时,三组患者治疗后椎体前缘、中间高度均较术前明显增加(P0.05),组间比较椎体前缘高度:C组B组A组,椎体中间高度:C组B组A组,且组间比较有统计学差异(P0.05); A组患者并发症的发生率(12.5%)明显低于B组(30.0%)、C组(41.0%),有统计学差异(P0.05)。结论 PKP术中注入小剂量骨水泥(2-4 mL)对于治疗老年女性OVCFs具有良好的治疗效果及较高的安全性。 相似文献
5.
6.
目的:探讨椎弓根螺钉三椎体内固定对脊椎爆裂性骨折患者椎体与神经功能状态的影响.方法:选取2013年7月至2015年1月于本院进行治疗的58例脊椎爆裂性骨折患者为研究对象,对其进行回顾性研究,将其根据手术方式不同分为对照组(短节段椎弓根内固定组)29例和观察组(椎弓根螺钉三椎体内固定组)29例,然后将两组患者手术前与手术后不同时间的伤椎恢复指标与血清神经功能相关指标进行比较.结果:观察组手术后不同时间的伤椎恢复指标中的后凸Cobb角、椎体平移率、椎体高度丢失率与血清神经功能相关指标中的BDNF、NSE、NGF及S100B均显著好于同期的对照组指标,并且明显好于其治疗前,均有显著性差异(P<0.05).结论:椎弓根螺钉三椎体内固定可更为有效地恢复脊椎爆裂性骨折患者椎体参数,并且更有助于神经功能状态的恢复. 相似文献
7.
《Neurocirugía (Asturias, Spain)》2022,33(5):237-241
Ewing sarcoma (ES) is a rare primary neoplasm in the lumbar adult spine and may mimic a benign tumor. In this case, after a patient's three-month history of lower back pain and rapidly progressing leg numbness and weakness, magnetic resonance imaging (MRI) showed a mass in the third lumbar vertebra. At a two-month follow-up, imaging showed a fracture, compression and lesion enlargement. Decompression and fixation confirmed ES, and the patient began combined radiotherapy and chemotherapy. Two months postoperatively, residual ES was suspected on MRI. The patient underwent a second surgery, and histopathology confirmed necrosis. A six-month follow-up after the first surgery showed no tumor recurrence. This case supports the inclusion of ES in the differential diagnosis of pathologic spinal fracture. Early decompression and spinal fixation are critical for preserving neurologic and spinal functions in ES complicated by a compression fracture. Combined adjuvant radiotherapy and chemotherapy remain the standard therapeutic strategy. 相似文献
8.
《Journal of vascular and interventional radiology : JVIR》2020,31(4):635-643
PurposeThis study evaluated the factors affecting contralateral and ipsilateral recurrent deep vein thrombosis (DVT) after iliac vein stent placement in patients with iliac vein compression syndrome (IVCS).Materials and MethodsData from 130 patients (95 female patients) who underwent catheter-directed thrombolysis and stent placement for IVCS with left lower leg thrombosis at a single institution were retrospectively analyzed. Mean patient age was 69.0 ± 14.0 years old. Median follow-up was 14 months (range, 3–164 months). Anticoagulation therapy was prescribed for 6 months, followed by lifelong antiplatelet therapy. Multivariate logistic regression analysis was performed to evaluate the factors affecting the development of contralateral and ipsilateral recurrent DVT.ResultsSeven patients (5.4%) developed contralateral DVT (median, 26 months; range, 2–61 months), and 11 patients (8.5%) developed ipsilateral DVT (median, 1 month; range, 0–53 months). Stent location (odds ratio [OR], 11.564; 95% confidence interval [CI], 1.159–115.417) and in-stent thrombosis during follow-up (OR, 15.142; 95% CI, 1.406–163.119) were predictors of recurrent contralateral DVT. Thrombophilia (OR, 47.560; 95% CI, 2.369–954.711), remaining inferior vena cava filter (OR, 30.552; 95% CI, 3.495–267.122), and in-stent thrombosis during follow-up (OR, 82.057; 95% CI, 2.915–2309.848) were predictors of ipsilateral DVT.ConclusionsContralateral DVT occurs late and is associated with extension of the iliac vein stent to the inferior vena cava and in-stent thrombosis. Ipsilateral DVT occurs relatively early and is associated with thrombophilia, remaining inferior vena cava filter, and in-stent thrombosis. 相似文献
9.
10.
目的 分析腰椎间盘突出症手术疗效不佳的原因,探讨提高疗效的方法。方法 随访本院1993-2003年腰椎间盘突出症行后路髓核摘除术病例236例,对术后腰腿痛症状未缓解或症状消失后再复发者复查X片、CT或MRI了解病因。结果手术疗效不佳者25例。疗效不佳的主要原因为残留髓核再突出、术后脊柱不稳倾向增加、对侧隐窝狭窄认识不足、神经根损伤、极外侧型椎问盘突出漏切、感染、术后椎管内瘢痕黏连等。全椎板切除术较椎板问开窗术更易发生椎管内瘢痕黏连(P<0.01)。结论首次手术时应尽可能取净髓核组织,对动力位摄片发现有椎问不稳倾向者行后外侧植骨或椎体问植骨融合,常规探查并妥善处理侧隐窝,牵拉神经根时间不应过长且用力轻柔。行腰椎间盘CT和MRI扫描时,应注意包括椎间盘相邻上下椎体的1/3部,以防止遗漏极外侧型椎问盘突出,尽量采用椎板间开窗术式以减少脊柱创伤,术中间断冲洗,术毕持续负压引流,以减少术后黏连,术中应严格无菌操作。 相似文献