全文获取类型
收费全文 | 27380篇 |
免费 | 2025篇 |
国内免费 | 879篇 |
专业分类
耳鼻咽喉 | 230篇 |
儿科学 | 602篇 |
妇产科学 | 174篇 |
基础医学 | 1989篇 |
口腔科学 | 1087篇 |
临床医学 | 3274篇 |
内科学 | 4648篇 |
皮肤病学 | 187篇 |
神经病学 | 681篇 |
特种医学 | 1680篇 |
外国民族医学 | 3篇 |
外科学 | 7862篇 |
综合类 | 3747篇 |
现状与发展 | 3篇 |
预防医学 | 484篇 |
眼科学 | 1381篇 |
药学 | 1261篇 |
13篇 | |
中国医学 | 430篇 |
肿瘤学 | 548篇 |
出版年
2024年 | 64篇 |
2023年 | 490篇 |
2022年 | 715篇 |
2021年 | 995篇 |
2020年 | 1005篇 |
2019年 | 998篇 |
2018年 | 969篇 |
2017年 | 983篇 |
2016年 | 933篇 |
2015年 | 956篇 |
2014年 | 1704篇 |
2013年 | 1810篇 |
2012年 | 1505篇 |
2011年 | 1707篇 |
2010年 | 1375篇 |
2009年 | 1373篇 |
2008年 | 1460篇 |
2007年 | 1425篇 |
2006年 | 1349篇 |
2005年 | 1211篇 |
2004年 | 1045篇 |
2003年 | 864篇 |
2002年 | 718篇 |
2001年 | 606篇 |
2000年 | 472篇 |
1999年 | 426篇 |
1998年 | 422篇 |
1997年 | 389篇 |
1996年 | 276篇 |
1995年 | 259篇 |
1994年 | 256篇 |
1993年 | 181篇 |
1992年 | 180篇 |
1991年 | 158篇 |
1990年 | 117篇 |
1989年 | 110篇 |
1988年 | 102篇 |
1987年 | 81篇 |
1986年 | 90篇 |
1985年 | 83篇 |
1984年 | 61篇 |
1983年 | 39篇 |
1982年 | 65篇 |
1981年 | 57篇 |
1980年 | 48篇 |
1979年 | 44篇 |
1978年 | 33篇 |
1977年 | 24篇 |
1976年 | 22篇 |
1975年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
931.
目的探讨彩色多普勒超声检测妊娠期糖尿病(GDM)孕妇胎儿肺静脉的应用价值。方法随机抽选45例经临床确诊的GDM孕妇(观察组),使用彩色多普勒超声检查胎儿心功能及肺静脉血流情况;随机选择同期正常孕妇45例(对照组)。比较两组胎儿肺静脉检测情况。结果观察组胎儿肺静脉参数异常,可表现为A波反转25例,降低20例,而对照组表现正常;观察组胎儿心室收缩期峰值速度为(0.28±0.04)m/s,舒张期峰值速度为(0.27±0.05)m/s,与对照组比较差异无统计学意义。观察组胎儿搏动指数和Tei指数分别为1.82±0.02和0.56±0.05,均高于对照组(P﹤0.05)。出生后对观察组胎儿进行随访,仅1例死亡,其余胎儿出生后生长状况良好(Apgar评分均在8.5分以上),超声心动图复查未见异常。结论彩色多普勒超声可清晰显示GDM孕妇胎儿肺静脉的血流频谱,操作简便,对孕妇和胎儿无不良影响,能更敏感地了解GDM孕妇胎儿心功能的变化,对临床及时发现病例、指导治疗有重要价值。 相似文献
932.
【】目的:探讨肾静脉多普勒超声检查早期发现代谢综合征(MS)肾脏损害的可行性。方法:选取2011-2013年在我院确诊的MS无肾脏损害患者组40例和MS早期肾脏损害患者组26例。入选患者均符合NCEP-ATPⅢ诊断标准。用彩色多普勒获取两组患者的肾叶间静脉多普勒血流频谱,分别记录收缩期最大血流速度(Vmax)、舒张末期最低血流速度(Vmin)及阻力指数(RI)。结果:MS早期肾损害组肾叶间静脉收缩期最大血流速度(Vmax)、舒张末期最低血流速度(Vmin)、及阻力指数(RI)相较无肾损害组均出现不同程度的减低,而尿白蛋白排泄率明显增加。结论:肾静脉彩色多普勒可以发现MS患者早期肾损害,可作为MS患者筛选早期肾损害的方法之一。 相似文献
933.
目的:探讨经皮颈内静脉长期导管在老年维持性血液透析患者中的应用及其常见并发症的防治。方法对2009年12月至2012年12月在中南大学湘雅医院行经皮颈内静脉长期置管的15例维持性血液透析老年患者的临床资料进行回顾性分析,观察置管术后情况、导管的使用情况、常见并发症的防治、透析充分性评价等。结果(1)实施颈内静脉长期置管18例次,其中3例为重新置管,置管成功率100%。(2)导管相关并发症:2例患者术后1周内出现置管处局部渗血;1例出现导管出口感染,2例发生导管相关性血流感染;3例患者出现导管血栓形成;2例诊断导管纤维鞘形成;1例因人为损坏出现导管破裂。经过相应处理后均使问题得到解决。(3)导管使用期限:本组患者长期导管使用时间为4~41个月,除1例死亡(原因为脑出血),3例为重新置管,余患者仍继续使用。(4)透析充分性评价:15例患者平均尿素下降率为72%,平均尿素清除指数达1.54。结论对于血管条件差无法建立动静脉内瘘的老年血透患者,使用颈内静脉长期导管行血液透析可以达到充分透析;提高置管及导管护理技术、加强健康宣教,能延长导管使用年限,减少导管并发症。 相似文献
934.
Nontumoral portal vein thrombosis (PVT) is an increasingly recognized complication in patients with cirrhosis. Substantial evidence shows that portal flow stasis, complex thrombophilic disorders, and exogenous factors leading to endothelial dysfunction have emerged as key factors in the pathogenesis of PVT. The contribution of PVT to hepatic decompensation and mortality in cirrhosis is debatable; however, the presence of an advanced PVT increases operative complexity and decreases survival after transplantation. The therapeutic decision for PVT is often determined by the duration and extent of thrombosis, the presence of symptoms, and liver transplant eligibility. Evidence from several cohorts has demonstrated that anticoagulation treatment with vitamin K antagonist or low molecular weight heparin can achieve recanalization of the portal vein, which is associated with a reduction in portal hypertension-related events and improved survival in cirrhotic patients with PVT. Consequently, interest in direct oral anticoagulants for PVT is increasing, but clinical data in cirrhosis are limited. Although the most feared consequence of anticoagulation is bleeding, most studies indicate that anticoagulation therapy for PVT in cirrhosis appears relatively safe. Interestingly, the data showed that transjugular intrahepatic portosystemic shunt represents an effective adjunctive therapy for PVT in cirrhotic patients with symptomatic portal hypertension if anticoagulation is ineffective. Insufficient evidence regarding the optimal timing, modality, and duration of therapy makes nontumoral PVT a challenging consequence of cirrhosis. In this review, we summarize the current literature and provide a potential algorithm for the management of PVT in patients with cirrhosis. 相似文献
935.
936.
Irina Girleanu Carol Stanciu Camelia Cojocariu Lucian Boiculese Ana-Maria Singeap Anca Trifan 《Saudi Journal Of Gastroenterology》2014,20(5):288-292
Background/Aim:
Portal vein thrombosis (PVT) has a high incidence in patients with liver cirrhosis and determines a poor prognosis of hepatic disease. The aim of our study was to define the natural course of partial PVT in cirrhotic patients, including survival and decompensation rates.Patients and Methods:
We performed a prospective, cohort study, in a tertiary referral center. There were 22 cirrhotic patients with partial nonmalignant PVT, without anticoagulant treatment, who were followed-up between January 2011 and October 2013. All patients were evaluated by Doppler abdominal ultrasound and computed tomography. Kaplan–Meier method was used to determine the difference in clinical events between the study subgroups.Results:
After a mean follow-up period of 20.22 months, partial PVT improved in 5 (22.73%), was stable in 11 (50%), and worsened in 6 (27.27%) patients. Hepatic decompensation rate at 6 and 18 months was higher in patients with worsened PVT than in those with stable/improved PVT (50% vs. 25%, P < 0.0001 and 100% vs. 56.25%, P < 0.0001, respectively). The survival rate at 6 months was 66.66% in worsened PVT group vs. 81.25% (P = 0.005) in stable/improved group, and 16.66% vs. 81.25% (P < 0.0001) at 18 months, respectively. Multivariate analysis showed that Model of End-Life Disease was the independent predictor of hepatic decompensation [hazard ratio (HR) 1.42; 95% confidence interval (CI): 1.08−1.87, P = 0.012] and survival (HR 1.76; 95% CI: 1.06−2.92, P = 0.028).Conclusions:
Nonmalignant partial PVT remained stable/improved in over half of cirrhotic patients and aggravated in more than one fourth in whom it negatively influenced the survival and decompensation rates. 相似文献937.
Recent evidence has shown that anti‐HCV‐positive serologic status is significantly linked to lower patient and graft survival after renal transplant, but conflicting results have been given on this point. The aim of this study was to conduct a systematic review of the published medical literature concerning the impact of HCV infection on all‐cause mortality and graft loss after RT. The relative risk of all‐cause mortality and graft loss was regarded as the most reliable outcome end‐point. Study‐specific relative risks were weighted by the inverse of their variance to obtain fixed‐ and random‐effect pooled estimates for mortality and graft loss with HCV across the published studies. We identified eighteen observational studies involving 133 530 unique renal transplant recipients. The summary estimate for adjusted relative risk (aRR) of all‐cause mortality was 1.85 with a 95% confidence interval (CI) of 1.49; 2.31 (P < 0.0001); heterogeneity statistics, Ri = 0.87 (P‐value by Q‐test = 0.001). The overall estimate for adjusted RR of all‐cause graft loss was 1.76 (95% CI, 1.46; 2.11) (P < 0.0001), heterogeneity statistics, Ri = 0.65 (P‐value by Q‐test = 0.001). Stratified analysis did not change meaningfully these results. Meta‐regression showed that living donor rate had a favourable influence on patient (P = 0.031) and graft survival (P = 0.01), whilst diabetes mellitus having a detrimental role on patient survival (P = 0.001). This meta‐analysis of observational studies supports the notion that HCV‐positive patients after RT have an increased risk of mortality and graft loss. Further studies are in progress to understand better the mechanisms underlying the relationship between HCV and mortality or graft dysfunction after renal transplant. 相似文献
938.
Ashish Aggarwal Kanika Puri Suthat Liangpunsakul 《World journal of gastroenterology : WJG》2014,20(19):5737-5745
Patients with liver cirrhosis were traditionally believed to be protected against development of blood clots.Lately,studies have shown that these patients may probably be at an increased risk of venous thrombotic complications.Although the hemostatic changes in the chronic liver disease patients and the factors that may predict bleeding vs thrombotic complications remains an area of active research,it is believed that the coagulation cascade is delicately balanced in these patients because of parallel reduced hepatic synthesis of pro and anticoagulant factors.Thrombotic state in cirrhotic patients is responsible for not only portal or non-portal thrombosis[deep vein thrombosis(DVT)and pulmonary embolism(PE)];it has also been associated with progression of liver fibrosis.The use of anticoagulants in cirrhosis patients is a challenging,and often a scary situation.This review summarizes the current literature on the prevalence of venous thrombosis(DVT and PE),risk factors and safety of prophylactic and therapeutic anticoagulation in patients with chronic liver disease. 相似文献
939.
Gurpreet Singh Dhillon Shohreh Honarbakhsh Antonio Di Monaco Ann Elizabeth Coling Kernerov Lenka Francesca Pizzamiglio Ross J. Hunter Rodney Horton Moussa Mansour Andrea Natale Vivek Reddy Massimo Grimaldi Petr Neuzil Claudio Tondo Richard J. Schilling 《Journal of cardiovascular electrophysiology》2020,31(6):1259-1269