全文获取类型
收费全文 | 43901篇 |
免费 | 3435篇 |
国内免费 | 1711篇 |
专业分类
耳鼻咽喉 | 437篇 |
儿科学 | 932篇 |
妇产科学 | 449篇 |
基础医学 | 3107篇 |
口腔科学 | 1598篇 |
临床医学 | 5160篇 |
内科学 | 7148篇 |
皮肤病学 | 1171篇 |
神经病学 | 1815篇 |
特种医学 | 2186篇 |
外科学 | 5707篇 |
综合类 | 7305篇 |
现状与发展 | 10篇 |
一般理论 | 4篇 |
预防医学 | 5340篇 |
眼科学 | 1023篇 |
药学 | 2888篇 |
29篇 | |
中国医学 | 1878篇 |
肿瘤学 | 860篇 |
出版年
2024年 | 70篇 |
2023年 | 891篇 |
2022年 | 1384篇 |
2021年 | 2204篇 |
2020年 | 2062篇 |
2019年 | 1752篇 |
2018年 | 1634篇 |
2017年 | 1547篇 |
2016年 | 1677篇 |
2015年 | 1539篇 |
2014年 | 3038篇 |
2013年 | 3100篇 |
2012年 | 2761篇 |
2011年 | 2922篇 |
2010年 | 2417篇 |
2009年 | 2269篇 |
2008年 | 2130篇 |
2007年 | 2127篇 |
2006年 | 1828篇 |
2005年 | 1695篇 |
2004年 | 1331篇 |
2003年 | 1169篇 |
2002年 | 976篇 |
2001年 | 936篇 |
2000年 | 751篇 |
1999年 | 557篇 |
1998年 | 544篇 |
1997年 | 426篇 |
1996年 | 277篇 |
1995年 | 383篇 |
1994年 | 320篇 |
1993年 | 219篇 |
1992年 | 233篇 |
1991年 | 210篇 |
1990年 | 171篇 |
1989年 | 183篇 |
1988年 | 165篇 |
1987年 | 152篇 |
1986年 | 122篇 |
1985年 | 127篇 |
1984年 | 112篇 |
1983年 | 57篇 |
1982年 | 73篇 |
1981年 | 65篇 |
1980年 | 66篇 |
1979年 | 62篇 |
1978年 | 60篇 |
1977年 | 53篇 |
1976年 | 62篇 |
1975年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Bulletin du cancer》2023,110(2):145-150
2.
角膜移植为治疗角膜盲的主要手段,而角膜移植排斥则是决定角膜植片存活时间和病人术后视力的关键。角膜得益于其特殊的眼前节“免疫赦免”状态,使得角膜移植能够在众多器官移植中享有极低的排斥率,然而排斥反应发生的风险依然存在。当机体处于遗传物质异常的特殊状态时,宿主将通过宏观调控“免疫赦免”状态对植片的保护作用或受体对移植物排异产生的有害作用,延迟或促进角膜移植排斥反应的发生,进而影响移植物的存活时间和透明度。该文综述与角膜移植排斥相关的多种全身性遗传疾病,总结全身性遗传疾病对角膜移植排斥的影响,浅析其发生的病理生理学机制以及诊疗的特殊性。 相似文献
3.
《Revista brasileira de otorrinolaringologia (English ed.)》2020,86(3):321-326
IntroductionMany studies have been done on proteomics, genomics, epigenetic, immunogenetics in many body fluids. Among these, circulating cell-free DNA (ccfDNA) entered the literature in 1948, but it has not been studied for many years due to technological deficiencies. Following recent advances, geno-metastasis has been mentioned and new research is needed in this area. ccfDNA is known to be an important biomolecule in this regard.ObjectiveThe presence of cell-free DNA in the circulatory system may offer a tremendous opportunity to provide novel biomarkers for thyroid diseases. This experimental study was conducted to determine the amount of ccfDNA in different thyroid diseases, then to evaluate whether the ccfDNA concentration varied between the disease groups and control group.MethodsIn total, we included 121 individuals in the present study. We collected blood samples and then determined the ccfDNA concentration in plasma of collected blood samples from three groups: thyroiditis (n = 33), benign (n = 37), and malignant (n = 30) and from a control group (n = 21).ResultsThe median values of the ccfDNA groups were found as 1610, 1665, 1685 and 576 ng/mL for the thyroiditis, benign, malign, and control groups, respectively. Findings showed that the ccfDNA of the three groups was significantly higher than the control (p < 0.0001). Each group was compared in terms of ccfDNA and the p-values of benign-thyroiditis, benign-malign, and thyroiditis-malign were 0.09, 0.65, and 0.29, respectively.ConclusionsThe clear differences between thyroid diseases and controls suggest that ccfDNA is worthy of attention as a biomarker for further evaluation of different thyroid diseases. Likewise, it might indicate a clear tendency that ccfDNA can also be used to distinguish different thyroid diseases. 相似文献
4.
5.
Elizabeth D. Krebs Robert B. Hawkins J. Hunter Mehaffey Clifford E. Fonner Alan M. Speir Mohammed A. Quader Jeffrey B. Rich Leora T. Yarboro Nicholas R. Teman Gorav Ailawadi 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1533-1542.e2
Objectives
Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.Methods
Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.Results
A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.Conclusions
Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight. 相似文献6.
《The American journal of emergency medicine》2020,38(8):1695.e1-1695.e3
Catamenial hemothorax is a rare manifestation of thoracic endometriosis syndrome. It is commonly seen associated with pelvic endometriosis in nulliparous reproductive-age women. Most cases are minor and self-limiting. We present a case of a 32-year-old woman who presented with prolonged worsening dyspnea and was found to have a massive hemothorax on evaluation. 相似文献
7.
8.
周蕾 《国际妇产科学杂志》2015,42(1):91-95
宫颈癌对妇女健康构成严重威胁,人乳头瘤病毒感染与宫颈病变及宫颈癌的发生密切相关。关于宫颈癌发生发展的机制仍在研究中。近年研究发现一种多功能核蛋白,即死亡结构域相关蛋白(death domain associated protein,Daxx),其与细胞内蛋白或病毒蛋白相互作用,参与调节细胞凋亡、转录调控、抗病毒等细胞活动,在不同途径中发挥不同的生理或病理作用。通过对Daxx功能及其作用机制的研究有助于进一步阐明宫颈癌发生发展的机制,有助于发现新的预防和治疗方法。综述Daxx的一般特性和研究现况及其在宫颈病变的研究进展。 相似文献
9.
《Australian critical care》2019,32(6):540-559
ObjectivesThe objective of this review was to describe cardiovascular risk (CVR) assessment methods and to identify evidence-based practice recommendations when dealing with population at risk of developing cardiovascular diseases.Review methods and data sourcesA literature review following the Arksey and O'Malley scoping review methodology was conducted. By using appropriate key terms, literature searches were conducted in PubMed, SciELO, Cochrane Library, Dialnet, ENFISPO, Medigraphic, ScienceDirect, Cuiden, and Lilacs databases. A complementary search on websites related to the area of interest was conducted. Articles published in English or Spanish in peer-review journals between 2010 and 2017. Critical appraisal for methodological quality was conducted. Data was extracted using ad-hoc tables and qualitatively synthesized.ResultsAfter eliminating duplicates, 55 325 records remained, and 1432 records were selected for screening. Out of these, 88 full-text articles were selected for eligibility criteria, and finally, 67 studies were selected for this review, and 25 studies were selected for evidence synthesis. In total, 23 CVR assessment tools have been identified, pioneered by the Framingham study. Qualitative findings were grouped into four thematic areas: assessment tools and scores, CVR indicators, comparative models, and evidence-based recommendations.ConclusionsIt is necessary to adapt the instruments to the epidemiological reality of the population. The most appropriate way to estimate CVR is to choose the assessment tool that best suits individual conditions, accompanied by a comprehensive assessment of the patient. More research is required to determine a single, adequate, and reliable tool. 相似文献
10.
目的通过CT影像测量了解漏斗胸Nuss矫形术前后胸廓径线的改变情况,探讨并分析Nuss矫形术对胸廓的影响及相关因素。方法对2014年1月至2018年12月郑州大学第一附属医院收治的50例行漏斗胸Nuss矫形术患儿的临床资料进行回顾性分析。50例患儿中男43例,女7例。所有患儿中存在脊柱侧弯6例,胸廓不对称12例,胸骨旋转11例。通过CT影像测量其放置矫形器前及取出矫形器后胸廓各椎体平面最大横内径及该平面胸脊间的距离,通过配对样本t检验比较矫形前后各径线的改变情况,以及通过独立样本t检验分析在不同年龄、性别、矫形时间、漏斗胸对称与否、是否合并脊柱侧弯等情况间的差异性。结果50例患儿均顺利完成矫形器置入术及矫形器拔除术,无明显术中及术后并发症,Nuss矫形后较矫形前相比,胸廓前后径在第8~12胸椎水平均较前增加,第3~5胸椎平面较前减小,胸廓横径在第8~10胸椎平面较前减小;年龄≤10岁、矫形时长≥2年及女性患儿胸廓前后径改变量在多个胸椎平面分别较年龄>10岁、矫形时长<2年及男性患儿大,P<0.05,差异具有统计学意义。结论漏斗胸Nuss矫形后前胸壁凹陷较前明显改善,并且在不同年龄和不同矫形时长间存在差异性,年龄较小及适当增加矫形时间可获得较好的矫形效果,而胸廓横径生长在一定程度上受限。 相似文献