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   87474篇
  免费   6464篇
  国内免费   2397篇
耳鼻咽喉   326篇
儿科学   1992篇
妇产科学   1034篇
基础医学   9201篇
口腔科学   720篇
临床医学   12910篇
内科学   13719篇
皮肤病学   540篇
神经病学   4402篇
特种医学   3689篇
外国民族医学   7篇
外科学   6770篇
综合类   14994篇
现状与发展   12篇
预防医学   6376篇
眼科学   908篇
药学   8625篇
  92篇
中国医学   7490篇
肿瘤学   2528篇
  2024年   203篇
  2023年   1274篇
  2022年   2253篇
  2021年   3453篇
  2020年   3280篇
  2019年   2665篇
  2018年   2539篇
  2017年   2741篇
  2016年   2898篇
  2015年   2940篇
  2014年   5505篇
  2013年   5763篇
  2012年   4875篇
  2011年   5245篇
  2010年   4142篇
  2009年   3807篇
  2008年   3891篇
  2007年   3955篇
  2006年   3516篇
  2005年   3218篇
  2004年   2853篇
  2003年   2619篇
  2002年   2269篇
  2001年   2145篇
  2000年   1754篇
  1999年   1511篇
  1998年   1400篇
  1997年   1464篇
  1996年   1178篇
  1995年   1170篇
  1994年   1121篇
  1993年   837篇
  1992年   847篇
  1991年   740篇
  1990年   604篇
  1989年   563篇
  1988年   572篇
  1987年   465篇
  1986年   414篇
  1985年   629篇
  1984年   522篇
  1983年   336篇
  1982年   456篇
  1981年   344篇
  1980年   312篇
  1979年   226篇
  1978年   173篇
  1977年   158篇
  1976年   152篇
  1975年   73篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Cardiac surgical patients with anaemia experience increased morbidity and mortality. Iron deficiency is the most common cause of pre-operative anaemia in this group. We designed and implemented the Cardiff Pathway, a pre-assessment and treatment pathway to identify cardiac surgical patients with anaemia and iron deficiency. Patients identified with anaemia and/or iron deficiency (Hb < 130 g.l-1 and ferritin < 100 μg.l-1) were offered intravenous iron infusion 20 mg.kg-1 pre-operatively. Treatment success was defined as Hb ≥ 130g.l-1 on the day of surgery. We analysed data from 447 patients: 300 (67%) were not anaemic; 75 (17%) were anaemic and treated with intravenous iron; and 72 (16%) were anaemic and not treated. Haemoglobin concentration increased in successfully treated anaemic patients by a mean (95%CI) of 17 (13–21) g.l-1 and they received a median (IQR [range]) of 0 (0–2 [0–15]) units of blood peri-operatively. Transfusion was avoided in 54% of the successfully treated anaemic patients, which was significantly more than the unsuccessfully treated anaemic (22%, p = 0.005) and untreated anaemic (28%, p = 0.018) patients and similar to non-anaemic patients who received a median (IQR [range] of 0 (0–1 [0–16])) units of blood and, 63% avoided transfusion). Mean (95%CI) Hb fell between pre-assessment and surgery in the untreated anaemic (-2 (0 to -4) g.l-1) and non-anaemic groups (-2 (-1 to -3) g.l-1). Twenty-one (7%) of the non-anaemic group became newly anaemic waiting for surgery. The Cardiff Pathway reliably identified patients with anaemia and iron deficiency. Anaemic patients who had their Hb restored to normal after treatment required less blood peri-operatively and over half of them required no transfusion at all.  相似文献   
992.
目的:通过应用中医传承辅助平台(V 2.5)挖掘中医药治疗小儿湿疹的组方用药规律,并对高频药物、用药模式及治疗思路进行探讨。方法:搜集国家知识基础设施数据库(CNKI)、中国学术期刊数据库(CSPD)及中文科技期刊数据库(CCD)中2000—2021年应用中医药治疗小儿湿疹的相关文献,经过筛选后建立方药数据库,运用中医传承辅助平台(V 2.5)集成的改进互信息法、关联规则Apriori算法、复杂系统熵聚类与无监督熵聚类等算法对药物频次、性味归经、用药模式、规则分析及新处方等结果进行输出,并进行网络可视化展示。结果:纳入处方200首,共涉及206味中药,高频药物包括甘草、白鲜皮、薏苡仁、茯苓、生地黄、金银花、蝉蜕、地肤子、防风、牡丹皮等,药性以寒性(52.76%)居多,药味以甘(38.89%)、苦(33.37%)、辛(21.96%)味为主,归经以胃经(1 138次)、脾经(1 088次)、肝经(1 061次)居多,并且得到药物之间的关联规则,以及新处方6个。结论:小儿湿疹用药以补虚药、利水渗湿药、清热药、清热解毒药、解表药为主,治疗以疏风清热,燥湿健脾,养血活血为主要大法,分析结果与本病诊疗指南较为吻合,可为小儿湿疹的临床治疗及新药开发提供参考。  相似文献   
993.
目的 探讨急性缺血性卒中溶栓治疗后使用益气活血类方剂干预的用药规律,预测核心药物防治脑缺血再灌注损伤的潜在作用机制。方法 检索中国知网、万方、维普和PubMed数据库中急性缺血性卒中溶栓治疗后使用益气活血类方有效干预的文献,对方中使用的药物进行频数、聚类及关联分析,依据关联规则选取置信度和支持度最高的核心药物,构建核心药物-活性成分-交集靶点网络图,并进行基因本体(gene ontology,GO)功能富集和京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)通路富集分析。结果 共筛选纳入232篇文献,涉及中药处方177首,包含中药119味,累计使用频次1903,以黄芪为首的高频药物28味,所有药物按功效可分为16种,药味总频次191,归经总频次292。高频药物聚类分析得到5个聚类,关联规则分析得到20组支持度较高的中药组合,其中支持度与置信度最高的二联药物组合为“黄芪-川芎”,三联药物组合为“黄芪-川芎-地龙”。网络药理学分析收集黄芪、川芎、地龙的活性成分30个;筛选“黄芪-川芎”防治脑缺血再灌注损伤的靶点91个,“黄芪...  相似文献   
994.
The efficacy of spirulina platensis (S. platensis) as an add-on therapy to metformin and its effect on atherogenic keys in patients with uncontrolled Type 2 Diabetes Mellitus (T2DM) was evaluated. Sixty patients were randomly assigned to S. platensis (2 g/day) or placebo group for three months while continuing metformin as their usual treatment. The efficacy of S. platensis was determined using the pre- and post-intervention HbA1c levels (primary outcome) as well as tracking FBS and lipid profiles levels (TC, LDL-C, TG, and HDL-C) as secondary outcomes at the different treatment time points (0,30,60,90 days). During the three–month intervention period, supplementation with S. platensis resulted in a significant lowering of HbA1c (↓1.43, p < 0.001) and FBS (↓ 24.94 mg/dL, p < 001) levels. Mean TG in the intervention group was found to be significantly lower in the intervention group than in controls (p < 0.001). Total cholesterol (TC) and its fraction, LDL-C, exhibited a fall (↓41.36 mg/dL and ↓38.4 mg/dL, respectively; p < 0.001) coupled with a marginal increase in the level of HDL-C (↑3 mg/dL; p < 0.001). Add-on therapy with S. platensis was superior to metformin regarding long-term glucose regulation and controlling blood glucose levels of subjects with T2DM. Also, as a functional supplement, S. platensis has a beneficial effect on atherogenic keys (TG and HDL-C) with no adverse events.  相似文献   
995.
中医学认为,气血失和,百病丛生,气血是构成人体和维持其生命活动的物质基础。现基于气血理论探讨中医治疗肺系疾病的辨治思路,认为肺系疾病的发病与气血关系密切,系因机体气血功能异常,加之外邪侵袭,导致“肺气虚弱,肺虚络瘀,肺热瘀阻,热壅血瘀”,总结出主要病机是“气血亏虚为本,痰热瘀阻为标”,治疗上应以“调和阴阳、理顺气血”为主要原则,临床上辨证应用“补肺理气、养血活血、化痰逐瘀、清肺热、利肺气、止咳平喘、凉血”之法,为临床从气血角度论治肺系疾病提供新思路。  相似文献   
996.
甲状腺未分化癌(ATC)发病率低、预后差,为指导临床医生和研究人员对其进行规范化诊断和治疗管理,美国甲状腺学会于2012年制定了第1版《甲状腺未分化癌病人管理指南》。随着分子检测和靶向治疗结果的不断积累,2021年美国甲状腺学会对该指南进行了更新。新版指南强调了BRAFV600E分子检测在诊断及靶向治疗中的作用,增加了靶向治疗的内容,对晚期无法切除的 ATC病人更加推荐靶向治疗,而化疗则被更多的用于过渡性治疗和最终治疗。此外,新版指南也对病人的人文关怀进行了丰富和完善。  相似文献   
997.
998.
999.
BackgroundTo evaluate to what degree preoperative urine white blood cell (WBC) and urine nitrite (NIT) values are predictive of postoperative infections following percutaneous nephrolithotomy (PCNL).MethodsA systematic literature search was performed of the PubMed, Embase, Cochrane Library, Wanfang Data, National Knowledge Infrastructure (CNKI), and China Science and Technology Journal Database (CSTJ or VIP) online databases to identify relevant studies that examined the predictive value of urine WBC or NIT as risk factors for post-PCNL infection, and the search was finished on February 28, 2020. Two independent reviewers screened the relevant studies, extracted necessary data from the eligible case-control studies (CCS), and assessed the quality of included studies through the Newcastle-Ottawa scale (NOS). RevMan 5.3 software and the Stata 16.0 software were used to complete the statistical analysis of data. Results are expressed as odds ratio (OR) with 95% confidence intervals (CIs).ResultsAccording to the statistical analysis of 12 eligible studies involving 6113 patients, positive urine WBC (WBC+: OR =3.86, 95% CI: 3.03–4.91, P<0.001) and positive NIT (NIT+: OR =7.81, 95% CI: 5.44–11.21, P<0.001) in preoperative tests were identified as independent risk factors for postoperative infections following PCNL.ConclusionsIn summary, as risk factors for postoperative infections, the presence of preoperative urine WBC+ and NIT+ should be evaluated as part of clinical procedure, in order to reduce infections of PCNL.  相似文献   
1000.
BACKGROUNDMaximum surgical blood order schedules were designed to eliminate unnecessary preoperative crossmatching prior to surgery in order to conserve blood bank resources. Most protocols recommend type and cross of 2 red blood cell (RBC) units for patients undergoing surgery for treatment of hip fracture. Preoperative hemoglobin has been identified as the strongest predictor of inpatient transfusion, but current maximum surgical blood order schedules do not consider preoperative hemoglobin values to determine the number of RBC units to prepare prior to surgery. AIMTo determine the preoperative hemoglobin level resulting in the optimal 2:1 crossmatch-to-transfusion (C:T) ratio in hip fracture surgery patients.METHODSIn 2015 a patient blood management (PBM) program was implemented at our institution mandating a single unit-per-occurrence transfusion policy and a restrictive transfusion threshold of < 7 g/dL hemoglobin in asymptomatic patients and < 8 g/dL in those with refractory symptomatic anemia or history of coronary artery disease. We identified all hip fracture patients between 2013 and 2017 and compared the preoperative hemoglobin which would predict a 2:1 C:T ratio in the pre PBM and post PBM cohorts. Prediction profiling and sensitivity analysis were performed with statistical significance set at P < 0.05. RESULTSFour hundred and ninety-eight patients who underwent hip fracture surgery between 2013 and 2017 were identified, 291 in the post PBM cohort. Transfusion requirements in the post PBM cohort were lower (51% vs 33%, P < 0.0001) than in the pre PBM cohort. The mean RBC units transfused per patient was 1.15 in the pre PBM cohort, compared to 0.66 in the post PBM cohort (P < 0.001). The 2:1 C:T ratio (inpatient transfusion probability of 50%) was predicted by a preoperative hemoglobin of 12.3 g/dL [area under the curve (AUC) 0.78 (95% confidence interval (CI), 0.72-0.83), Sensitivity 0.66] in the pre PBM cohort and 10.7 g/dL [AUC 0.78 (95%CI, 0.73-0.83), Sensitivity 0.88] in the post PBM cohort. A 50% probability of requiring > 1 RBC unit was predicted by 11.2g/dL [AUC 0.80 (95%CI, 0.74-0.85), Sensitivity 0.87] in the pre PBM cohort and 8.7g/dL [AUC 0.78 (95%CI, 0.73-0.83), Sensitivity 0.84] in the post-PBM cohort.CONCLUSIONThe hip fracture maximum surgical blood order schedule should consider preoperative hemoglobin in determining the number of units to type and cross prior to surgery.  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