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   522425篇
  免费   41830篇
  国内免费   11920篇
耳鼻咽喉   6778篇
儿科学   12705篇
妇产科学   8808篇
基础医学   42278篇
口腔科学   13676篇
临床医学   54735篇
内科学   59044篇
皮肤病学   6736篇
神经病学   28016篇
特种医学   13457篇
外国民族医学   40篇
外科学   53363篇
综合类   80424篇
现状与发展   21篇
一般理论   52篇
预防医学   61727篇
眼科学   6889篇
药学   50082篇
  684篇
中国医学   54885篇
肿瘤学   21775篇
  2024年   6562篇
  2023年   10799篇
  2022年   17538篇
  2021年   22896篇
  2020年   21933篇
  2019年   25886篇
  2018年   23065篇
  2017年   19928篇
  2016年   17315篇
  2015年   16327篇
  2014年   32325篇
  2013年   34056篇
  2012年   29120篇
  2011年   31447篇
  2010年   25343篇
  2009年   22969篇
  2008年   22026篇
  2007年   22281篇
  2006年   19438篇
  2005年   16648篇
  2004年   13693篇
  2003年   11995篇
  2002年   9411篇
  2001年   8283篇
  2000年   6944篇
  1999年   5891篇
  1998年   4851篇
  1997年   4512篇
  1996年   3879篇
  1995年   3691篇
  1994年   3502篇
  1993年   2872篇
  1992年   2836篇
  1991年   2469篇
  1990年   2187篇
  1989年   1991篇
  1988年   1884篇
  1987年   1646篇
  1985年   4765篇
  1984年   5792篇
  1983年   4087篇
  1982年   4793篇
  1981年   4158篇
  1980年   3692篇
  1979年   3391篇
  1978年   2905篇
  1977年   2207篇
  1976年   2506篇
  1975年   1845篇
  1974年   1618篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Background and aimsDiabetes can often remain undiagnosed or unregistered in administrative databases long after its onset, even when laboratory test results meet diagnostic criteria. In the present work, we analyse healthcare data of the Veneto Region, North East Italy, with the aims of: (i) developing an algorithm for the identification of diabetes from administrative claims (4,236,007 citizens), (ii) assessing its reliability by comparing its performance with the gold standard clinical diagnosis from a clinical database (7525 patients), (iii) combining the algorithm and the laboratory data of the regional Health Information Exchange (rHIE) system (543,520 subjects) to identify undiagnosed diabetes, and (iv) providing a credible estimate of the true prevalence of diabetes in Veneto.Methods and resultsThe proposed algorithm for the identification of diabetes was fed by administrative data related to drug dispensations, outpatient visits, and hospitalisations. Evaluated against a clinical database, the algorithm achieved 95.7% sensitivity, 87.9% specificity, and 97.6% precision. To identify possible cases of undiagnosed diabetes, we applied standard diagnostic criteria to the laboratory test results of the subjects who, according to the algorithm, had no diabetes-related claims. Using a simplified probabilistic model, we corrected our claims-based estimate of known diabetes (6.17% prevalence; 261,303 cases) to account for undiagnosed cases, yielding an estimated total prevalence of 7.50%.ConclusionWe herein validated an algorithm for the diagnosis of diabetes using administrative claims against the clinical diagnosis. Together with rHIE laboratory data, this allowed to identify possibly undiagnosed diabetes and estimate the true prevalence of diabetes in Veneto.  相似文献   
92.
In the previous research, we found that anticancer agent LS-1-2F could cause the vacuolation of tumor cells. Herein we investigated the effect of compound LS-1-2F on the endocytosis of macromolecules, including fluorescence quantum dots, human serum albumin, single-stranded RNA, and monoclonal antibody, into tumor cells. We found that LS-1-2F could accelerate the endocytosis of these large molecules by laser confocal microscope and flow cytometry. The effect of LS-1-2F on the improvement of the internalization efficiency of Herceptin biosimilar was particularly significant. Promoting endocytosis will help increase the efficiency of liquid-phase drug uptake in drug-resistant cancer cells and could potentially facilitate the use of drugs in nanoparticle delivery vehicles.  相似文献   
93.
目的探讨无创产前检测(NIPT)联合孕妇血清可溶性转铁蛋白受体(sTfR)、生长分化因子(GDF)-15、红细胞体积分布宽度变异系数(RDW-CV)检测,对胎儿β-地中海贫血的诊断价值。 方法选择2017年1月至2018年6月,于自贡市妇幼保健院接受羊膜腔穿刺术确诊胎儿为β-地中海贫血的120例孕妇为研究对象。根据其妊娠胎儿的β-地中海贫血轻、中、重型,将其分别纳入轻型组(n=48)、中型组(n=40)与重型组(n=32)。选取同期于本院建卡进行常规产前检查,并且妊娠胎儿发育正常的100例健康孕妇作为对照,纳入对照组。采集4组孕妇空腹肘静脉血,提取孕妇外周血浆中胎儿细胞外游离DNA(cfDNA),采用2次PCR方法扩增后,采用反向斑点杂交方法检测胎儿β-地中海贫血基因。采用酶联免疫吸附测定法,测定4组孕妇血清sTfR、GDF-15、RDW-CV水平。对4组孕妇血清sTfR、GDF-15与RDW-CV水平分别总体比较,采用单因素方差分析,进一步两两比较,采用最小显著性差异(LSD)-t检验。与胎儿β-地中海贫血诊断"金标准"比较,计算NIPT联合孕妇血清sTfR、GDF-15、RDW-CV水平及这4项指标单独检测,对于胎儿β-地中海贫血诊断的敏感度、特异度、粗符合率、阳性预测值、阴性预测值。本研究严格按照2013年修订的《世界医学协会赫尔辛基宣言》要求进行。4组孕妇年龄及其妊娠胎儿的胎龄等一般临床资料比较,差异均无统计学意义(P>0.05)。 结果①夫妻双方β-地中海贫血基因型相同的40例孕妇中,NIPT与羊膜腔穿刺术对于胎儿β-地中海贫血诊断的符合率为90.0%(36/40);夫妻双方β-地中海贫血基因型不同的80例孕妇中,上述2种方法对于胎儿β-地中海贫血诊断的符合率亦为90. 0%(72/80)。②4组孕妇血清sTfR、GDF-15、RDW-CV水平分别总体比较,差异均有统计学意义(F=2 283.445、323.181、45.900,P均<0.001),进一步两两比较,任意2组孕妇血清sTfR、GDF-15、RDW-CV水平比较,差异均有统计学意义(P<0.05),并且孕妇血清sTfR、GDF-15、RDW-CV水平随着β-地中海贫血胎儿严重程度增加而逐渐升高。③NIPT联合孕妇血清sTfR、GDF-15、RDW-CV水平检测,对于胎儿β-地中海贫血诊断的敏感度、特异度、粗符合率、阳性预测值与阴性预测值,分别为86.7%、88.0%、87.3%、86.7%与84.6%,其特异度与阳性预测值,均显著高于单独检测孕妇血清sTfR、GDF-15、RDW-CV水平,并且差异均有统计学意义(与孕妇血清sTfR水平比较:χ2=8.866、5.301,P=0.003、0.021;与孕妇血清GDF-15水平比较:χ2=9.765、5.929,P=0.002、0.015;与孕妇血清RDW-CV水平比较:χ2=7.167、4.327,P=0.007、0.038)。 结论孕妇血清sTfR、GDF-15、RDW-CV可能成为诊断胎儿β-地中海贫血的生物标志物,NIPT联合这3项指标检测,可提高诊断胎儿β-地中海贫血的特异度与阳性预测值。由于本研究纳入样本量相对较小,NIPT联合孕妇血清sTfR、GDF-15、RDW-CV水平,对胎儿β-地中海贫血的诊断价值,仍然有待进一步研究、证实。  相似文献   
94.
95.
BackgroundOpen pelvic fractures are rare injuries, associated with high patient morbidity and mortality. Few studies have investigated the impact of patient demographics, comorbidities, and injury related factors on complication and mortality rates. The purpose of this study was to: (1) identify the overall incidence of complications and mortality after open pelvic fractures, (2) compare patient factors between those who did and did not develop complications, (3) identify perioperative independent risk factors for complications and mortality.MethodsA query was performed for patients with open pelvic fractures between 2007 and 2017 using the American College of Surgeons National Trauma Data Bank. Patient and injury specific variables were collected and complications were identified using International Classification of Disease Ninth and Tenth edition Codes. Patient demographic and perioperative data was compared using Fisher’s exact test and chi-square test for categorical variables, and Welch’s t-test for continuous variables. Using pooled data from multiple imputations, logistic regressions were used to calculate odds ratios and confidence intervals of independent risk factors for complications.ResultsA total of 19,834 open pelvic fracture cases were identified, with 9622 patients (48.5%) developing at least one complication. Patients who developed complications were older (35.0 vs 38.1 years), and had higher Injury Severity Scores (17.7 vs 26.5), lower Glasgow Coma Scores (14.2 vs 11.7), and a larger proportion presenting with hypotension (21% vs 6.9%). After pooled regression involving 19 factors, these were the strongest independent predictors of inpatient complication and mortality.ConclusionWe report a mortality rate of 14%, with an inclusive complication rate of 48.5%. Evaluating risk factors for morbidity and mortality for this devastating orthopaedic injury provides knowledge of an inherently sparse population.Level of EvidenceLevel II, Retrospective study.  相似文献   
96.
The National Cardiovascular Data Registry PINNACLE (Practice Innovation and Clinical Excellence) Registry is the largest outpatient cardiovascular practice registry in the world. It tracks real-world management and quality of 4 common cardiovascular conditions: heart failure, coronary artery disease, atrial fibrillation, and hypertension. In 2013, the PINNACLE Registry contained information on 2,898,505 patients, cared for by 4,859 providers in 431 practices. By 2017, the registry contained information on 6,040,996 patients, cared for by 8,853 providers in 724 practices. During this time period, care processes for PINNACLE patients generally improved. Among patients with heart failure, combined beta-blocker and renin-angiotensin antagonist medication rates increased from 60.7% to 72.8%. Among patients with coronary artery disease, statin medication rates increased from 66% to 80.1%. Among patients with atrial fibrillation, oral anticoagulation rates increased from 52.7% to 65.2%. In contrast, blood pressure control rates among patients with hypertension were largely stable. PINNACLE data also fueled a variety of quality measurement programs and 51 peer-reviewed publications.  相似文献   
97.
ABSTRACT

Between 2015 and 2018, the RISE Learning Network facilitated learning on approaches, practices, methods, and tools that promote recovery and reintegration of children affected by sexual exploitation. Spanning three regions (Sub-Saharan Africa, South Central Asia, and Latin America and the Caribbean), the RISE Learning Network implemented two learning projects. The first project focused on monitoring (M&E Learning Project) and aimed to generate understanding of approaches and tools that could effectively monitor children and families’ reintegration outcomes. The specific purpose of RISE is to promote learning on reintegration of children affected by sexual exploitation; however, the remit of this Learning Project was to generate evidence on the reintegration of children who have been separated from their families for a range of reasons. This is to ensure that learning from different, but often related, areas of work can be included and compared to strengthen understanding of what successful reintegration of children could look like. The mid- and end-term reviews of the M&E Learning Project have captured lessons learned on how practitioners can approach monitoring of reintegration to mainstream it into their programme cycle. Key lessons learned include the importance of focusing on monitoring outcomes through participatory tools and the benefit of flexible, peer-to-peer learning approaches between practitioners using a variety of monitoring tools. This learning contributes to the nascent evidence base on what effective and efficient capturing of reintegration outcomes on children can look like, in addition to strengthening understanding of what successful reintegration for children and families means. The learnings can inform programming; monitoring, evaluation and learning frameworks; and other interventions around reintegration to ensure the holistic wellbeing of children and families.  相似文献   
98.
对于创伤骨科患者来说,急救药品与物品事在急救过程中必不可少的物品。急救药品的管理和存放,也是直接影响急救效果的重要因素。因此现代医疗机构为了进一步提高医疗的安全度,必须要加强对急救药品和急救物品的规范管理,但是在这个过程当中仍然出现了许多问题,整体效果提升度不高。  相似文献   
99.
100.
BackgroundGranulicatella adiacens is a nutritional variant of streptococcus (NVS), which has been rarely reported as an etiologic agent in spondylodiscitis (SD).Material and methodsWe report a case of a 51-year-old male with from chronic low-back pain associated with right sciatica and ipsilateral monoparesis. Spinal MRI showed radiological signs on L1-L2 and L5-S1 discs consistent with SD. We also performed a systematic review of the pertinent literature in order to retrieve all the key information regarding microbiological and clinical features.ResultsIncluding our patients, seven cases with a mean age 56 ± 10.2 years were reported in English literature. Six patients were conservatively managed with antibiotic therapy (66%), whereas three with surgery in combination with antibiotics (33%). An endocarditis was associated in three cases, and a pacemaker infection in one. All patients received targeted antibiotic therapy resulting in a quick improvement of clinical symptoms with favorable outcome. Our case is the only with a skip spontaneous SD, which needed a surgical decompression due to the associated neurological symptoms.ConclusionsThis incidence of SD sustained by Granulicatella adiances could be underestimated due to their particular microbiological conditions requested for their cultures. However, this infection should be suspected in cases of culture-negative SD, especially when associated with endocarditis.  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