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   533023篇
  免费   47204篇
  国内免费   18355篇
耳鼻咽喉   4497篇
儿科学   11011篇
妇产科学   6624篇
基础医学   85748篇
口腔科学   9935篇
临床医学   43011篇
内科学   85545篇
皮肤病学   7734篇
神经病学   44510篇
特种医学   11565篇
外国民族医学   136篇
外科学   42259篇
综合类   72949篇
现状与发展   37篇
一般理论   35篇
预防医学   28989篇
眼科学   8683篇
药学   64758篇
  83篇
中国医学   21777篇
肿瘤学   48696篇
  2023年   7941篇
  2022年   10771篇
  2021年   20844篇
  2020年   19318篇
  2019年   19741篇
  2018年   19205篇
  2017年   18776篇
  2016年   18335篇
  2015年   20426篇
  2014年   31850篇
  2013年   36562篇
  2012年   30683篇
  2011年   35529篇
  2010年   29698篇
  2009年   29238篇
  2008年   28292篇
  2007年   27356篇
  2006年   24703篇
  2005年   21865篇
  2004年   18760篇
  2003年   16637篇
  2002年   13163篇
  2001年   11750篇
  2000年   9832篇
  1999年   8671篇
  1998年   6436篇
  1997年   6047篇
  1996年   5472篇
  1995年   5491篇
  1994年   4984篇
  1993年   4343篇
  1992年   3661篇
  1991年   3285篇
  1990年   2822篇
  1989年   2395篇
  1988年   2226篇
  1987年   1745篇
  1986年   1521篇
  1985年   2649篇
  1984年   2720篇
  1983年   1826篇
  1982年   2039篇
  1981年   1701篇
  1980年   1408篇
  1979年   1207篇
  1978年   951篇
  1977年   762篇
  1976年   761篇
  1975年   573篇
  1974年   430篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
ObjectiveThe use of mechanical circulatory support (MCS) in lung transplantation has been steadily increasing over the prior decade, with evolving strategies for incorporating support in the preoperative, intraoperative, and postoperative settings. There is significant practice variability in the use of these techniques, however, and relatively limited data to help establish institutional protocols. The objective of the AATS Clinical Practice Standards Committee (CPSC) expert panel was to review the existing literature and establish recommendations about the use of MCS before, during, and after lung transplantation.MethodsThe AATS CPSC assembled an expert panel of 16 lung transplantation physicians who developed a consensus document of recommendations. The panel was broken into subgroups focused on preoperative, intraoperative, and postoperative support, and each subgroup performed a focused literature review. These subgroups formulated recommendation statements for each subtopic, which were evaluated by the entire group. The statements were then developed via discussion among the panel and refined until consensus was achieved on each statement.ResultsThe expert panel achieved consensus on 36 recommendations for how and when to use MCS in lung transplantation. These recommendations included the use of veno-venous extracorporeal membrane oxygenation (ECMO) as a bridging strategy in the preoperative setting, a preference for central veno-arterial ECMO over traditional cardiopulmonary bypass during the transplantation procedure, and the benefit of supporting selected patients with MCS postoperatively.ConclusionsAchieving optimal results in lung transplantation requires the use of a wide range of strategies. MCS provides an important mechanism for helping these critically ill patients through the peritransplantation period. Despite the complex nature of the decision making process in the treatment of these patients, the expert panel was able to achieve consensus on 36 recommendations. These recommendations should provide guidance for professionals involved in the care of end-stage lung disease patients considered for transplantation.  相似文献   
2.
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area.  相似文献   
3.
《Pancreatology》2022,22(8):1175-1180
BackgroundHepatic steatosis has been described as a common finding in adults following total pancreatectomy with islet autotransplantation (TPIAT) but it is unknown if this occurs in children and adolescents.ObjectivesTo define the frequency of post-TPIAT hepatic steatosis in a sample of children and adolescents and to identify clinical predictors of incident steatosis post-TPIAT.MethodsIn this prospective study, consecutive participants at least 1-month post-TPIAT underwent a liver MRI with proton density fat fraction (PDFF) and blood draw at our pediatric academic medical center between April 2021 and January 2022. Comparison clinical pre-TPIAT liver MRI or ultrasound and insulin use and graft function data were extracted from the medical record. T-tests were used for the comparison of means across continuous variables between participants with and without post-TPIAT steatosis.ResultsA total of 20 participants (mean: 13 ± 4 years; 12 female) were evaluated. Mean liver PDFF at research MRI was 7.4 ± 6.2% (range: 2–25%). Seven participants (35%) had categorical hepatic steatosis (PDFF>5%) post-TPIAT, five of whom had pre-TPIAT steatosis, reflecting a 13% (2/15; 95% CI: 2–40%) incidence of post-TPIAT steatosis. Participant characteristics were not significantly different between subgroups with and without post-TPIAT steatosis. Mean PDFF at research MRI was not different between graft function subgroups (7.5% optimal/good vs. 7.3% marginal/failure; p = .96).ConclusionOur study shows a moderate prevalence but low incidence of hepatic steatosis in a small sample of children and adolescents post-TPIAT. This study raises questions about a causal relationship between TPIAT and hepatic steatosis.  相似文献   
4.
The COVID-19 pandemic caused by the SARS-CoV-2 virus has significantly disrupted and burdened the diagnostic workup and delivery of care, including transfusion, to cancer patients across the globe. Furthermore, cancer patients suffering from solid tumors or hematologic malignancies were more prone to the infection and had higher morbidity and mortality than the rest of the population. Major signaling pathways have been identified at the intersection of SARS-CoV-2 and cancer cells, often leading to tumor progression or alteration of the tumor response to therapy. The reactivation of oncogenic viruses has also been alluded to in the context and following COVID-19. Paradoxically, certain tumors responded better following the profound infection-induced immune modulation. Unveiling the mechanisms of the virus-tumor cell interactions will lead to a better understanding of the pathophysiology of both cancer progression and virus propagation. It would be challenging to monitor, through the different cancer registries, retrospectively, the response of patients who have been previously exposed to the virus in contrast to those who have not contracted the infection.  相似文献   
5.
Obstructive sleep apnea (OSA) is a sleep disorder common among patients with type 2 diabetes (T2D). The aim of this quality improvement project was to increase identification and referral for sleep study for individuals with T2D at moderate to high risk for OSA. Pre- and post-intervention patient samples were analyzed to compare the number of referrals for sleep study. Results demonstrated that none of the patients pre-intervention were referred for sleep study compared with 77% of patients post-intervention. This project demonstrated implementing an evidence-based tool to screen patients with T2D for OSA leads to higher rates of detection and referral.  相似文献   
6.
目的分析同型半胱氨酸(Hcy)、溶血磷脂酸(LPA)及转化生长因子-β1(TGF-β1)在创伤性骨折下肢静脉栓塞中的预测价值。方法选取2019年3月至2020年2月商丘市第一人民医院收治的104例创伤性骨折者(观察组),根据有无DVT:有DVT组33例,无DVT组71例;根据创伤严重程度:轻度组61例,重度组43例。另选取本院同期92例健康体检者设为对照组。比较不同人群、不同病情程度以及有无DVT者血浆Hcy、LPA及血清TGF-β1水平,分析Hcy、LPA及TGF-β1对DVT的预测价值。结果观察组Hcy、LPA及TGF-β1表达水平均明显高于对照组,差异均有统计学意义(P<0.05)。重度组Hcy、LPA及TGF-β1表达水平明显高于轻度组,差异均有统计学意义(P<0.05)。有DVT组者Hcy、LPA及TGF-β1表达水平明显高于无DVT组,差异均有统计学意义(P<0.05)。依据ROC曲线分析可知,Hcy+LPA+TGF-β1三者联合预测创伤性骨折后发生DVT敏感度和特异度分别为88.90%、8130%,明显高于三者单独检测(P<0.05)。结论Hcy、LPA及TGF-β1在创伤性骨折发生下肢静脉栓塞时水平均明显升高,三者联合检测对下肢静脉栓塞早期诊断有重要的临床价值。  相似文献   
7.
8.
9.
10.
《Value in health》2022,25(6):1010-1017
ObjectivesSurvival extrapolation for chimeric antigen receptor T-cell therapies is challenging, owing to their unique mechanistic properties that translate to complex hazard functions. Axicabtagene ciloleucel is indicated for the treatment of relapse or refractory diffuse large B-cell lymphoma after 2 or more lines of therapy based on the ZUMA-1 trial. Four data snapshots are available, with minimum follow-up of 12, 24, 36, and 48 months. This analysis explores how survival extrapolations for axicabtagene ciloleucel using ZUMA-1 data can be validated and compared.MethodsThree different parametric modeling approaches were applied: standard parametric, spline-based, and cure-based models. Models were compared using a range of metrics, across the 4 data snapshot, including visual fit, plausibility of long-term estimates, statistical goodness of fit, inspection of hazard plots, point-estimate accuracy, and conditional survival estimates.ResultsStandard and spline-based parametric extrapolations were generally incapable of fitting the ZUMA-1 data well. Cure-based models provided the best fit based on the earliest data snapshot, with extrapolations remaining consistent as data matured. At 48 months, the maximum survival overestimate was 8.3% (Gompertz mixture-cure model) versus the maximum underestimate of 33.5% (Weibull standard parametric model).ConclusionsWhere a plateau in the survival curve is clinically plausible, cure-based models may be helpful in making accurate predictions based on immature data. The ability to reliably extrapolate from maturing data may reduce delays in patient access to potentially lifesaving treatments. Additional research is required to understand how models compare in broader contexts, including different treatments and therapeutic areas.  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