全文获取类型
收费全文 | 107632篇 |
免费 | 10790篇 |
国内免费 | 8065篇 |
专业分类
耳鼻咽喉 | 906篇 |
儿科学 | 1061篇 |
妇产科学 | 1183篇 |
基础医学 | 12537篇 |
口腔科学 | 1920篇 |
临床医学 | 15371篇 |
内科学 | 15177篇 |
皮肤病学 | 1138篇 |
神经病学 | 6088篇 |
特种医学 | 3797篇 |
外国民族医学 | 62篇 |
外科学 | 9331篇 |
综合类 | 18981篇 |
现状与发展 | 25篇 |
一般理论 | 15篇 |
预防医学 | 7646篇 |
眼科学 | 3436篇 |
药学 | 11517篇 |
142篇 | |
中国医学 | 7054篇 |
肿瘤学 | 9100篇 |
出版年
2024年 | 331篇 |
2023年 | 1741篇 |
2022年 | 5176篇 |
2021年 | 6371篇 |
2020年 | 4866篇 |
2019年 | 3796篇 |
2018年 | 4082篇 |
2017年 | 3643篇 |
2016年 | 3411篇 |
2015年 | 5348篇 |
2014年 | 6579篇 |
2013年 | 5755篇 |
2012年 | 8492篇 |
2011年 | 9553篇 |
2010年 | 5882篇 |
2009年 | 4647篇 |
2008年 | 5721篇 |
2007年 | 5404篇 |
2006年 | 5383篇 |
2005年 | 5289篇 |
2004年 | 3140篇 |
2003年 | 2970篇 |
2002年 | 2399篇 |
2001年 | 2088篇 |
2000年 | 2196篇 |
1999年 | 2260篇 |
1998年 | 1486篇 |
1997年 | 1410篇 |
1996年 | 1123篇 |
1995年 | 1049篇 |
1994年 | 864篇 |
1993年 | 547篇 |
1992年 | 635篇 |
1991年 | 548篇 |
1990年 | 484篇 |
1989年 | 437篇 |
1988年 | 358篇 |
1987年 | 291篇 |
1986年 | 229篇 |
1985年 | 189篇 |
1984年 | 83篇 |
1983年 | 53篇 |
1982年 | 44篇 |
1981年 | 38篇 |
1980年 | 26篇 |
1979年 | 26篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1969年 | 4篇 |
1968年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 552 毫秒
931.
932.
Sternal wound infection (SWI) is a devastating complication after cardiac surgery. Platelet‐rich plasma (PRP) may have a positive impact on sternal wound healing. A systematic review with meta‐analyses was performed to evaluate the clinical effectiveness of topical application of autologous PRP for preventing SWI and promoting sternal wound healing compared to placebo or standard treatment without PRP. Relevant studies published in English or Chinese were retrieved from the Cochrane Central Register of Controlled Trials (The Cochrane Library), PubMed, Ovid EMBASE, Web of Science, Springer Link, and the WHO International Clinical Trials Registry Platform (ICTRP) using the search terms “platelet‐rich plasma” and “sternal wound” or “thoracic incision.” References identified through the electronic search were screened, the data were extracted, and the methodological quality of the included studies was assessed. The meta‐analysis was performed for the following outcomes: incidence of SWI, incidence of deep sternal wound infection (DSWI), postoperative blood loss (PBL), and other risk factors. In the systematic review, totally 10 comparable studies were identified, involving 7879 patients. The meta‐analysis for the subgroup of retrospective cohort studies (RSCs) showed that the incidence of SWI and DSWI in patients treated with PRP was significantly lower than that in patients without PRP treatment. However, for the subgroup of randomized controlled trials (RCTs), there was no significant difference in the incidence of SWI or DSWI after intervention between the PRP and control groups. There was no significant difference in PBL in both RCTs and RSCs subgroups. Neither adverse reactions nor in‐situ recurrences were reported. According to the results, PRP could be considered as a candidate treatment to prevent SWI and DSWI. However, the quality of the evidence is too weak, and high‐quality RCTs are needed to assess its efficacy on preventing SWI and DSWI. 相似文献
933.
Jian Zhang Qingyuan Liang Dean Qin Jiefu Song Qijun An Xiaojian Wang Zhongtao Zhao 《The journal of spinal cord medicine》2021,44(3):340
Study Design: Systematic review and meta-analysis.Objective: To compare the effectiveness and safety between anterior and posterior approach, and determine the best surgical methods for the treatment of ossification of the posterior longitudinal ligament (OPLL) in the cervical spine.Methods: We searched the Cochrane Library, PubMed, CNKI and Wanfang Med Data databases from January 2007 to March 2018. Japanese Orthopaedic Association (JOA) scores, cervical lordosis, functional recovery rates, excellent and good outcomes of the surgical approaches, and complication and reoperation rates were analyzed. RevMan 5.3 was utilized for data analysis.Results: Eleven studies were included in the meta-analysis. By comparing the anterior and posterior approaches for the treatment of OPLL in the cervical spine, statistically significant differences were found in the preoperative initial JOA, the postoperative final JOA scores, functional recovery rates, complication rates, excellent and good outcomes of the surgical approaches and reoperation rates. However, no statistically significant difference in the occurrence of the preoperative and postoperative cervical lordosis was noted.Conclusion: The anterior approach is superior to the posterior approach in terms of the postoperative final JOA score, functional recovery rate, and clinical outcomes. Although the complication and reoperation rates of the anterior approach are higher than those of the posterior approach. We recommend the anterior approach for the treatment of OPLL when patients with occupying ratio ≥ 60%. In addition, high-quality studies with long-term follow-up and large sample size are also needed. 相似文献
934.
935.
Fei Li Xu Wang Yuetang Wang Xuan Li Shihua Zhao Yongjian Wu Wei Wang 《Annals of thoracic and cardiovascular surgery》2021,27(2):112
Objective: Our study aimed to evaluate short- and long-term outcomes of patients who required emergent conversion from transcatheter aortic valve implantation (TAVI) to open surgery. Besides, the reasons and procedural settings of emergent cardiac surgery (ECS) were also reported.Methods: We retrospectively reviewed the patients who underwent TAVI in our institution between 2012 and 2019 and collected the clinical data of cases who converted from TAVI to bail-out surgery. Telephone and outpatient follow-ups were performed.Results: Of 516 TAVI patients, 20 required ECS, and the bail-out surgery occurred less frequently with the increase in TAVI volume. The most common reason for conversion was left ventricular perforation (7/20, 35.0%). Thirty-day mortality was 35.0% in ECS patients. Kaplan–Meier survival curves showed that the cumulative survival rate was 65.0% at 1 year, 50.1% at 5 years in all ECS patients, and 77.1% at 5 years in patients who survived over 30 days after conversion.Conclusion: Although the bail-out operation was performed immediately after TAVI abortion, ECS still associated with high 30-day mortality. The long-term survival benefit was seen in patients surviving from bail-out surgery. An experienced TAVI team is of crucial importance in avoiding ECS-related life-threatening complications and providing effective salvage surgery. 相似文献
936.
937.
938.
939.
Effects of bariatric surgery on patients with obesity and polycystic ovary syndrome: a meta-analysis
Zhao Tian Yi-Chao Zhang Yue Wang Xiao-Hong Chang Hong-Lan Zhu Yan Zhao 《Surgery for obesity and related diseases》2021,17(8):1399-1408
BackgroundBariatric surgery is effective for polycystic ovary syndrome (PCOS), while the exact mechanism remains unclear.ObjectivesTo assess the impact of bariatric surgery on PCOS patients and further explore the possible mechanism.SettingA meta-analysis.MethodsWe searched PubMed, Web of Science, The Cochrane Library, and Embase to identify relevant studies published before November 2020.ResultsTwenty-one studies met our inclusion criteria, and we identified 552 patients with PCOS study. Results showed that the prevalence of preoperative PCOS, menstrual irregularity, hirsutism, type 2 diabetes (T2D), hypertension, infertility, and depression significantly decreased after bariatric surgery. Levels of total testosterone, fasting insulin, and luteinizing hormone (LH) decreased and estradiol increased, while levels of follicle-stimulating hormone (FSH) and LH/FSH did not show significant changes during the 3-month follow-up. There were decreases in testosterone and fasting insulin levels when the postoperative follow-up time was 6 months or ≥12 months. Levels of fasting blood glucose and triglycerides were significantly reduced after 6 months or ≥12 months of bariatric surgery. High-density lipoprotein (HDL) and sex hormone-binding globulin (SHBG) significantly improved ≥12 months after bariatric surgery.ConclusionSymptoms of PCOS and related complications are significantly alleviated after bariatric surgery. In addition, we found a significant improvement on anomalous secretion of gonadotropins, glucose metabolism, and lipid metabolism in patients with PCOS after bariatric surgery. 相似文献
940.
目的锯齿状腺瘤被公认为结直肠癌的癌前病变,锯齿状通路被认为是可以独立发展成结直肠癌的重要通路,但目前对于锯齿状腺瘤恶变的相关危险因素还知之甚少。本文旨在分析锯齿状腺瘤在结直肠中的分布特点及潜在恶变因素。方法采用病例对照研究方法,回顾性收集2017年4月至2019年7月期间在中国医学科学院肿瘤医院行肠镜检查并经病理诊断为锯齿状腺瘤患者的临床资料,排除同时具有两种及以上病理类型病变的患者。总结锯齿状腺瘤的临床特征,并进行单因素和Logistic多因素回归分析,探讨锯齿状腺瘤发生恶变的影响因素。结果共在28730例行肠镜检查患者中,发现311例(1.08%)锯齿状腺瘤患者,共发现锯齿状腺瘤372枚。按WHO分类,无蒂锯齿状腺瘤/息肉22枚(5.9%),传统锯齿状腺瘤84枚(22.6%),未分类锯齿状腺瘤266枚(71.5%)。病理结果显示:无异型增生病变106枚(28.5%),低级别上皮内瘤变病变228枚(61.3%),高级别上皮内瘤变或癌变38枚(10.2%)。病变长径<10 mm有204枚(54.8%),≥10 mm有168枚(45.2%);病变位于左半结直肠238枚(64.0%),右半结肠134枚(36.0%)。内镜下大体分型:扁平型16枚(4.3%),无蒂型174枚(46.8%),亚蒂型117枚(31.5%),带蒂型59枚(15.9%)。窄带成像国际结直肠内镜(NICE)分型:Ⅰ型85枚(22.8%),Ⅱ型280枚(75.3%),Ⅲ型4枚(1.1%)。单因素分析显示,病变大小、病变位置、病变部位及不同WHO分类与结直肠锯齿状腺瘤发生恶变有关(均P<0.05);不同NICE分型的锯齿状腺瘤,其恶变率的差异亦有统计学差异(P=0.001)。多因素分析结果显示,病变长径≥10 mm(OR=6.699,95%CI:2.843~15.786)以及病变位于左半结直肠(OR=2.657,95%CI:1.042~6.775)是结直肠锯齿状腺瘤发生恶变的独立危险因素。结论锯齿状腺瘤主要位于左半结直肠,当病变长径≥10 mm或病变位于左半结直肠时,易发生恶变。 相似文献