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   87202篇
  免费   5979篇
  国内免费   1694篇
耳鼻咽喉   277篇
儿科学   1659篇
妇产科学   974篇
基础医学   8413篇
口腔科学   1042篇
临床医学   10226篇
内科学   15514篇
皮肤病学   400篇
神经病学   4878篇
特种医学   2477篇
外国民族医学   2篇
外科学   6573篇
综合类   12121篇
现状与发展   6篇
一般理论   1篇
预防医学   12716篇
眼科学   665篇
药学   9515篇
  68篇
中国医学   4883篇
肿瘤学   2465篇
  2024年   200篇
  2023年   1195篇
  2022年   2232篇
  2021年   3380篇
  2020年   3340篇
  2019年   2512篇
  2018年   2433篇
  2017年   2616篇
  2016年   2803篇
  2015年   2891篇
  2014年   6144篇
  2013年   6407篇
  2012年   5534篇
  2011年   5989篇
  2010年   4646篇
  2009年   4442篇
  2008年   4303篇
  2007年   3981篇
  2006年   3624篇
  2005年   3028篇
  2004年   2548篇
  2003年   2294篇
  2002年   1877篇
  2001年   1674篇
  2000年   1437篇
  1999年   1175篇
  1998年   990篇
  1997年   985篇
  1996年   846篇
  1995年   817篇
  1994年   722篇
  1993年   669篇
  1992年   578篇
  1991年   517篇
  1990年   521篇
  1989年   444篇
  1988年   470篇
  1987年   436篇
  1986年   390篇
  1985年   494篇
  1984年   467篇
  1983年   302篇
  1982年   380篇
  1981年   322篇
  1980年   326篇
  1979年   224篇
  1978年   211篇
  1977年   185篇
  1976年   173篇
  1973年   147篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
51.
In this review we summarize the impact of the various modalities of breast cancer therapy coupled with intrinsic patient factors on incidence of subsequent treatment-induced myelodysplasia and acute myelogenous leukemia (t-MDS/AML). It is clear that risk is increased for patients treated with radiation and chemotherapy at younger ages. Radiation is associated with modest risk, whereas chemotherapy, particularly the combination of an alkylating agent and an anthracycline, carries higher risk and radiation and chemotherapy combined increase the risk markedly. Recently, treatment with granulocyte colony-stimulating factor (G-CSF), but not pegylated G-CSF, has been identified as a factor associated with increased t-MDS/AML risk. Two newly identified associations may link homologous DNA repair gene deficiency and poly (ADP-ribose) polymerase inhibitor treatment to increased t-MDS/AML risk. When predisposing factors, such as young age, are combined with an increasing number of potentially leukemogenic treatments that may not confer large risk singly, the risk of t-MDS/AML appears to increase. Patient and treatment factors combine to form a biological cascade that can trigger a myelodysplastic event. Patients with breast cancer are often exposed to many of these risk factors in the course of their treatment, and triple-negative patients, who are often younger and/or BRCA positive, are often exposed to all of them. It is important going forward to identify effective therapies without these adverse associated effects and choose existing therapies that minimize the risk of t-MDS/AML without sacrificing therapeutic gain.

Implications for Practice

Breast cancer is far more curable than in the past but requires multimodality treatment. Great care must be taken to use the least leukemogenic treatment programs that do not sacrifice efficacy. Elimination of radiation and anthracycline/alkylating agent regimens will be helpful where possible, particularly in younger patients and possibly those with homologous repair deficiency (HRD). Use of colony-stimulating factors should be limited to those who truly require them for safe chemotherapy administration. Further study of a possible leukemogenic association with HRD and the various forms of colony-stimulating factors is badly needed.
  相似文献   
52.
目的:分析鼻塞式同步间歇正压通气(NIPPV)联合布地奈德雾化治疗ARDS(新生儿急性呼吸窘迫综合征)疾病的临床应用效果。方法:纳入病例是2017年5月—2019年11月收治的104例ARDS新生儿,随机平均分为两组。参照组52例采纳CPAP(持续气道正压通气通气)治疗,实验组52例采纳NIPPV+布地奈德雾化治疗,对比两组呼吸机通气时间、用氧时间、住院时间、血气指标以及并发症发生情况。结果:实验组呼吸机通气时间、用氧时间、住院时间均明显短于参照组,差异有统计学意义P<0.05;实验组治疗3 d后PaCO2明显低于参照组,实验组治疗3 d后PH以及PaO2明显高于参照组,差异有统计学意义P<0.05;实验组并发症发生率(3.85%,2/52)明显低于参照组(21.15%,11/52),差异有统计学意义P<0.05。结论:NIPPV+布地奈德雾化可有效缩短ARDS患者机械通气时间,改善血气指标,降低并发症发生率,值得借鉴。  相似文献   
53.
The activation of the innate and adaptive immune systems by SARS-CoV-2 causes the release of several inflammatory cytokines, including IL-6. The inflammatory hypercytokinemia causes immunopathological changes in the lungs including vascular leakage, and alveolar edema. As a result of these changes in the lungs, hypoxia and acute respiratory distress syndrome occur in patients with COVID-19. Even though there are clinical trials on the development of therapeutics and vaccines, there are currently no licensed vaccines or therapeutics for COVID-19. Pharmacological approaches have shown poor results in sepsis-like syndromes caused by the hypercytokinemia. Suppressing the cytokine storm is an important way to prevent the organ damage in patients with COVID-19. Extracorporeal blood purification could be proposed as an adjunctive therapy for sepsis, aiming to control the associated dysregulation of the immune system, which is known to protect organ functions. Several extracorporeal blood purification therapies are now available, and most of them target endotoxins and/or the cytokines and aim improving the immune response. For this purpose, plasmapheresis and immunoadsorption may be an important adjunctive treatment option to manage the complications caused by cytokine storm in critically ill patients with COVID-19.  相似文献   
54.
Background and objectivesThe ideal timing of tranexamic acid administration in total knee arthroplasty with tourniquet remains unclear. Our primary objective was to prove if administering it before surgical incision, instead of before releasing the tourniquet, reduces postoperative bleeding. A second objective was to determine whether a second dose reduces post-operative bleeding.Material and methodsA prospective, double-blind clinical trial was performed on 212 patients scheduled for total knee arthroplasty. They were randomised into 4 groups. Tranexamic acid was administered before the surgical incision in “pre-induction groups” (1 and 2), and just before the tourniquet release in “pre-release groups” (3 and 4). Groups 2 and 4 received a second dose 3 hours post-surgery. Main outcome was postoperative bleeding (visible blood loss and calculated total bleeding). Secondary outcomes were haemoglobin variations, complications and transfusion rate.ResultsThe mean calculated total bleeding was 1563 ml (95%CI: 1445 to 1681) in preinduction groups versus 1576 ml (95%CI: 1439 to 1713) in pre-release groups (P = .9); 1579 ml (95%CI: 1452 to 1706) in single-dose groups versus 1559 ml (95%CI: 1431 to 1686) in double-dose groups (P = .82). One patient was transfused. The mean haemoglobin at discharge was 10.4 g/dl (95%CI: 10.2 to 10.7) in singledose groups versus 10.8 (95%CI: 10.6 to 11.1) in double-dose groups (P = .06).ConclusionsThere were no differences in bleeding or transfusion regarding the time of tranexamic acid administration. The second dose had not impact on outcomes.Trial registration: EudraCT 2016-000071-24.  相似文献   
55.
糖尿病已成为全球威胁人类健康的三大慢性非传染性疾病之一。需要外科手术的患者占所有糖尿病患者的25%,其围手术期病死率、并发症以及住院时间较正常人明显增加,因此对于糖尿病患者围手术期的处理方案显得尤为重要。但目前对于围手术期血糖控制范围仍众说纷纭,综合各研究结论,笔者认为将血糖控制在7.8~10 mmol/L是一个较为理想的范围。在患者术前、术中及术后应联合多学科制定各项相应的治疗方案,围手术期尤为注意避免患者发生低血糖和电解质紊乱的发生。也亟待后续大规模的随机对照试验进一步确定有效的血糖控制目标。  相似文献   
56.
57.
We investigated changes in brain function supporting inhibitory control under age-controlled incentivized conditions, separating age- and performance-related activation in an accelerated longitudinal design including 10- to 22-year-olds. Better inhibitory control correlated with striatal activation during neutral trials, while Age X Behavior interactions in the striatum indicated that in the absence of extrinsic incentives, younger subjects with greater reward circuitry activation successfully engage in greater inhibitory control. Age was negatively correlated with ventral amygdala activation during Loss trials, suggesting that amygdala function more strongly mediates bottom-up processing earlier in development when controlling the negative aspects of incentives to support inhibitory control. Together, these results indicate that with development, reward-modulated cognitive control may be supported by incentive processing transitions in the amygdala, and from facilitative to obstructive striatal function during inhibitory control.  相似文献   
58.
Rotary ventricular assist devices (VADs) are less sensitive to preload than the healthy heart, resulting in inadequate flow regulation in response to changes in patient cardiac demand. Starling‐like physiological controllers (SLCs) have been developed to automatically regulate VAD flow based on ventricular preload. An SLC consists of a cardiac response curve (CRC) which imposes a nonlinear relationship between VAD flow and ventricular preload, and a venous return line (VRL) which determines the return path of the controller. This study investigates the importance of a physiological VRL in SLC of dual rotary blood pumps for biventricular support. Two experiments were conducted on a physical mock circulation loop (MCL); the first compared an SLC with an angled physiological VRL (SLC‐P) against an SLC with a vertical VRL (SLC‐V). The second experiment quantified the benefit of a dynamic VRL, represented by a series of specific VRLs, which could adapt to different circulatory states including changes in pulmonary (PVR) and systemic (SVR) vascular resistance versus a fixed physiological VRL which was calculated at rest. In both sets of experiments, the transient controller responses were evaluated through reductions in preload caused by the removal of fluid from the MCL. The SLC‐P produced no overshoot or oscillations following step changes in preload, whereas SLC‐V produced 0.4 L/min (12.5%) overshoot for both left and right VADs. Additionally, the SLC‐V had increased settling time and reduced controller stability as evidenced by transient controller oscillations. The transient results comparing the specific and standard VRLs demonstrated that specific VRL rise times were improved by between 1.2 and 4.7 s ( = 3.05 s), while specific VRL settling times were improved by between 2.8 and 16.1 seconds ( = 8.38 s) over the standard VRL. This suggests only a minor improvement in controller response time from a dynamic VRL compared to the fixed VRL. These results indicate that the use of a fixed physiologically representative VRL is adequate over a wide variety of physiological conditions.  相似文献   
59.
目的分析真菌性血流感染的病原菌分布以及耐药特征,为真菌血流感染的早期合理用药提供理论依据。 方法回顾性分析武汉大学人民医院2016年1月至2018年12月收治的真菌性血流感染者的菌群、科室分布以及耐药性。 结果入组192例真菌血流感染者的血培养样本中共分离192株真菌,其中白色念珠菌检出率为31.77%(61/192),其次热带念珠菌检出率为18.75%(36/192);重症医学科检出率最高为33.85%(65/192)。所有菌株均对两性霉素B敏感,对其他抗菌药物耐药率分别为5-氟胞嘧啶4.49%(9/192)、伊曲康唑5.73%(11/192)、氟康唑10.94%(21/192)和伏立康唑11.46%(22/192);除两性霉素B外,2016至2018年真菌对其他抗菌药物的耐药率均逐年上升,其中2018年所分离192株光滑念珠菌对伊曲康唑耐药菌率达46.7%。 结论真菌血流感染病原菌以念珠菌属为主,对目前抗真菌药物具有较高敏感性,但耐药率逐年上升,加强监测血培养病原菌变化及耐药趋势对指导临床用药至关重要。  相似文献   
60.
李良兰  李文君 《全科护理》2020,18(4):459-463
[目的]探讨护理质量控制中心在提升基层医院护理质量和管理水平的作用。[方法]护理质量控制中心指导基层医院建立完善的质量控制标准、质量评价体系,协助制订护士培训、检查、考核计划,并行使护理质量控制中心的监督、管理职责,促使各项制度得到有效落实。[结果]在护理质量控制中心的指导下,基层医院的护理管理体系、管理制度、评价体系逐步完善,护理人员业务水平、病人满意度及健康知识知晓率得到提升(P<0.05)。[结论]护理质量控制中心能在基层医院的护理质量管理中发挥积极作用。  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