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   45324篇
  免费   4623篇
  国内免费   2489篇
耳鼻咽喉   368篇
儿科学   831篇
妇产科学   325篇
基础医学   3478篇
口腔科学   828篇
临床医学   5327篇
内科学   4484篇
皮肤病学   550篇
神经病学   1056篇
特种医学   1719篇
外国民族医学   1篇
外科学   4022篇
综合类   11330篇
现状与发展   16篇
一般理论   1篇
预防医学   5051篇
眼科学   872篇
药学   5273篇
  62篇
中国医学   4704篇
肿瘤学   2138篇
  2024年   525篇
  2023年   619篇
  2022年   1341篇
  2021年   1704篇
  2020年   1568篇
  2019年   899篇
  2018年   966篇
  2017年   1225篇
  2016年   1012篇
  2015年   1725篇
  2014年   2172篇
  2013年   2573篇
  2012年   3894篇
  2011年   4059篇
  2010年   3685篇
  2009年   3158篇
  2008年   3585篇
  2007年   3277篇
  2006年   3018篇
  2005年   2446篇
  2004年   1807篇
  2003年   1541篇
  2002年   1237篇
  2001年   1184篇
  2000年   943篇
  1999年   477篇
  1998年   148篇
  1997年   146篇
  1996年   150篇
  1995年   143篇
  1994年   102篇
  1993年   83篇
  1992年   134篇
  1991年   122篇
  1990年   95篇
  1989年   114篇
  1988年   76篇
  1987年   77篇
  1986年   59篇
  1985年   53篇
  1984年   45篇
  1983年   30篇
  1982年   20篇
  1981年   29篇
  1980年   25篇
  1979年   31篇
  1978年   22篇
  1977年   16篇
  1975年   11篇
  1974年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.

Background

Non-traumatic osteonecrosis of the femoral head (ONFH) is a refractory osteonecrosis disease caused by an abnormal blood supply to bone tissue. However, therapeutic hip preservation strategies are diverse, and the therapeutic outcomes are not ideal.

Objective

A network meta-analysis was performed to assess the effect of hip preservation treatments on non-traumatic ONFH.

Methods

We searched public electronic databases through May 15, 2017 using the following keywords: “femoral head necrosis osteonecrosis”; “femoral head osteonecrosis”; “osteonecrosis of femoral head”; “avascular necrosis of femoral head”; “necrosis of femoral”; and “random*”. The primary outcome in the present analysis was the treatment failure rate. Secondary outcomes included the Harris hip and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores.

Results

We included 21 articles assessing a total of 1415 hips in our analysis. In the network meta-analysis, the treatments were ranked by the surface under the cumulative ranking curve (SUCRA). Core decompression (CD) plus cytotherapy was most likely to reduce the treatment failure rate (SUCRA score = 18.9%), followed by alendronate treatment (SUCRA score = 17.8%), cocktail treatments (SUCRA score = 15.6%), extracorporeal shock wave therapy (ESWT) plus alendronate (SUCRA score = 15.4%), and avascular biomaterials plus cytotherapy (SUCRA score = 13.8%) in a frequentist framework; similar results were obtained in a Bayesian framework. For the secondary outcomes, ESWT was most likely to improve the Harris hip score (SUCRA score = 33.7%), followed by ESWT plus alendronate (SUCRA score = 33.1%) and cocktail (SUCRA score = 19.6%) treatments in a frequentist framework. A traditional analysis showed that the effect of CD plus cytotherapy was significantly better than the effect of CD alone in improving the WOMAC score (SMD, ?6.01; 95% CI, ?7.81 to ?4.22; p < 0.001).

Conclusion

CD plus cytotherapy is a relatively superior treatment for reducing treatment failure rates in early and intermediate ONFH patients, and ESWT is the most effective treatment for improving Harris hip scores.  相似文献   
53.
54.
目的:探讨VCE取材Bethesda 2001报告系统在宫颈癌筛查中的意义。方法:采用VCE取材Bethesda2001报告系统对3 056例健康体检女性进行阴道细胞学检查,并对不明确意义的不典型鳞状上皮细胞(ASC-US)以上病变者经阴道镜取材进行宫颈组织病理学诊断。结果:阴道细胞学检查(VCE取材Bethesda 2001报告系统)检出宫颈异常鳞状上皮细胞66例,阳性率2.15%。其中不明确意义的不典型鳞状上皮细胞(ASC-US)17例(25.76%),不除外高度病变的不典型鳞状上皮细胞(ASC-H)4例,(6.06%),低度鳞状上皮内病变(LSIL)28例(42.42%),高度鳞状上皮内病变(HSIL)14例(21.21%),宫颈鳞癌(SCC)3例(4.55%)。66例细胞学阳性诊断病例经宫颈活检组织病理学诊断CIN I级以上病变60例(90.91%),其中CIN Ⅰ级35例(53.03%),CIN Ⅱ级12例(18.18%),CIN Ⅲ级7例(10.61%),宫颈鳞癌6例(9.09%)。结论:VCE取材Bethesda2001报告系统取材方便、报告准确,阴道细胞学检查阳性诊断与病理诊断符合率高达90.91%,VCE取材Bethesda2001报告系统在宫颈癌筛查中具有重要意义。  相似文献   
55.
Through a modified agar well diffusion assay, antagonism of a novel chitinase-producing strain C3 against the phytopathogenic fungi including Phoma wasabiae Yokogi,Heterostrophus, Exserohilum Turcicum, Curwularia (Walk) Boed, Thantephorus cucumris, Fusarium graminearum was tested. The data showed that the crude cxtracts of strain C3 had stable antifungal activity in the range of pH 5.0 to pH 8.0. The active components were heat labile and sensitive to proteinase K. A series of experiments supported that the compound responsible for inhibitory activity appeared to be ehitinase. The 16s rDNA analysis indicated that C3 was subject to genus Burkholderia. Pbenotypic characterization of C3 was also consisted with the result of molecular identification.  相似文献   
56.
目的探讨神经电生理监测技术在脊柱微创椎弓根置钉术中的应用价值。方法回顾分析2011年2月~2014年2月浙江省丽水市人民医院骨科收治的胸腰椎爆裂性骨折并行胸腰椎椎弓根置钉术患者资料52例,在经皮置钉过程中实时自发肌电(spontaneous electromyography,s EMG)和触发肌电(triggered electromyography,t EMG)监测、体感诱发电位(somatosensory evoked potential,SEP)检测。随访患者术后临床神经功能及置钉椎体薄层CT。结果术后9例患者SEP波幅较术前波幅升高,提示症状可能较术前改善,术后随访证实麻木感较术前改善。术中抓获暴发肌电3例,确认钉道破壁。222枚螺钉置入中,经CT提示有21枚螺钉穿破椎弓根,t EMG阳性23例,假阳性2例,并且螺钉破壁后位置与t EMG阈值无明显关联。按美国脊髓损伤学会(America spinal injury association,ASIA)分级随访患者神经功能,术前A级2例、B级3例、C级8例、D级30例、E级9例;末次随访A级1例、B级1例、C级2例、D级17例、E级31例,差异具有统计学意义(P0.05)。结论 EMG和SEP有各自的作用,联合监测具有互补作用,为指导脊柱椎弓根镙钉置入术的进程和提高手术安全性起到一定作用。  相似文献   
57.
Management of interstitial cystitis/bladder pain syndrome (IC/BPS) remains a challenge due to poor understanding on its etiology. Complementary and alternative medicine (CAM), as an optional treatment, has been widely used, because no definitive conventional therapy is available. The different domain of CAM provides miscellaneous treatments for IC/BPS, which mainly include dietary modification, nutraceuticals, bladder training, biofeedback, yoga, massage, physical therapy, Qigong, traditional Chinese medicine and acupuncture. Clinical evidence has shown that each therapy can certainly benefit a portion of IC/BPS patients. However, the target patient group of each therapy has not been well studied and randomized, controlled trials are needed to further confirm the efficacy and reliability of CAM on managing IC/BPS. Despite these limitations, CAM therapeutic characteristics including non-invasive and effectiveness for specific patients allow clinicians and patients to realize multimodal and individualized therapy for IC/BPS.  相似文献   
58.
59.
The role of metformin (MET) on treatment effect of diabetic tuberculosis (TB) patients has not been studied in China. Thus, we conducted a retrospective study to investigate whether MET exhibited more efficacy in combination with anti-TB regimens for diabetic TB patients. All patients recruited came from five tuberculosis control and prevention institutes from July 2009 to July 2016 and completed 3 years of follow-up. We used chi-square test or Fisher’s exact test to evaluate the demographic characteristics and the frequency of clinical outcome between MET and non-MET group. A total of 58 TB patients with diabetes mellitus (DM), of these 27.6% (16/58) patients in the MET group and 72.4% (42/58) patients in the non-MET group, there was no significant difference in blood glucose level between MET and non-MET group (P?=?0.494), in addition, there was a higher proportion of treatment success (93.8 vs. 71.4%) and culture conversions by the end of 2 months (87.5 vs. 71.4%) among MET group; the relapse rates of patients in MET and non-MET group were 6.3% (1/16) and 35.7% (15/42) through a 3-year follow-up (P?=?0.045). Our data revealed that the use of MET as a combination drug with existing regimen improved the success rate of anti-TB treatment and reduced the relapse rate in TB patients with DM.  相似文献   
60.
In the event of a high degree of airway obstruction, endotracheal intubation can be impossible and even dangerous, because it can cause complete airway obstruction, especially in patients with high tracheal lesions. However, a smaller endotracheal tube under the guidance of a bronchoscope can be insinuated past obstructive tumor in most noncircumferential cases. Here we report a case of successful fiberoptic bronchoscopy-assisted endotracheal intubation in a patient undergoing surgical resection of a large, high tracheal tumor causing severe tracheal stenosis. A 42-year-old Chinese man presented with dyspnea, intermittent irritable cough, and sleep deprivation for one and a half years. X-rays and computed tomography scan of the chest revealed an irregular pedunculated soft tissue mass within the tracheal lumen. The mass occupied over 90% of the lumen and caused severe tracheal stenosis. Endotracheal intubation was done to perform tracheal tumor resection under general anesthesia. After several failed conventional endotracheal intubation attempts, fiberoptic bronchoscopy-assisted intubation was successful. The patient received mechanical ventilation and then underwent tumor resection and a permanent tracheostomy. This case provides evidence of the usefulness of the fiberoptic bronchoscopy-assisted intubation technique in management of an anticipated difficult airway and suggests that tracheal intubation can be performed directly in patients with a tracheal tumor who can sleep in the supine position, even if they have occasional sleep deprivation and severe tracheal obstruction as revealed by imaging techniques.Key words: Tracheal tumors, Fiberoptic bronchoscopy, Difficulty intubation, Difficult airwayPrimary tumors of the trachea, mostly malignant, are rare, accounting for fewer than 0.1% of all tumors.1 Surgical resection is the major option that has the potential to cure all patients with benign and low-grade tumors and most patients with malignant tracheal tumors.1 Since surgical procedure often requires the airway to be shared by the anesthetist and the surgeon, patients who undergo tracheal tumor resection often present with a considerable degree of airway obstruction, which makes anesthetic management during surgical resection challenging.2 In the event of a high degree of airway obstruction, endotracheal intubation can be impossible and even dangerous because it can cause complete airway obstruction, especially in patients with high tracheal lesions.3 However, tumors are not circumferential in most cases, and a small endotracheal tube can be insinuated past a highly obstructive tumor under the guidance of bronchoscopy.3 Here we report a case of successful fiberoptic bronchoscopy-assisted endotracheal intubation in a patient undergoing surgical resection of a large, high tracheal tumor causing severe tracheal stenosis.  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