全文获取类型
收费全文 | 88854篇 |
免费 | 7726篇 |
国内免费 | 2947篇 |
专业分类
耳鼻咽喉 | 152篇 |
儿科学 | 3435篇 |
妇产科学 | 429篇 |
基础医学 | 4828篇 |
口腔科学 | 225篇 |
临床医学 | 13550篇 |
内科学 | 24311篇 |
皮肤病学 | 360篇 |
神经病学 | 2069篇 |
特种医学 | 3507篇 |
外国民族医学 | 13篇 |
外科学 | 7287篇 |
综合类 | 18168篇 |
一般理论 | 1篇 |
预防医学 | 4185篇 |
眼科学 | 537篇 |
药学 | 8670篇 |
105篇 | |
中国医学 | 4491篇 |
肿瘤学 | 3204篇 |
出版年
2024年 | 104篇 |
2023年 | 1644篇 |
2022年 | 2073篇 |
2021年 | 4154篇 |
2020年 | 4275篇 |
2019年 | 3264篇 |
2018年 | 3027篇 |
2017年 | 3353篇 |
2016年 | 3542篇 |
2015年 | 3413篇 |
2014年 | 6141篇 |
2013年 | 6708篇 |
2012年 | 5537篇 |
2011年 | 5807篇 |
2010年 | 4632篇 |
2009年 | 4263篇 |
2008年 | 4152篇 |
2007年 | 4291篇 |
2006年 | 3940篇 |
2005年 | 3614篇 |
2004年 | 3158篇 |
2003年 | 2929篇 |
2002年 | 1993篇 |
2001年 | 1781篇 |
2000年 | 1537篇 |
1999年 | 1215篇 |
1998年 | 995篇 |
1997年 | 934篇 |
1996年 | 861篇 |
1995年 | 834篇 |
1994年 | 716篇 |
1993年 | 543篇 |
1992年 | 529篇 |
1991年 | 421篇 |
1990年 | 364篇 |
1989年 | 341篇 |
1988年 | 324篇 |
1987年 | 264篇 |
1986年 | 249篇 |
1985年 | 361篇 |
1984年 | 262篇 |
1983年 | 150篇 |
1982年 | 173篇 |
1981年 | 153篇 |
1980年 | 117篇 |
1979年 | 106篇 |
1978年 | 75篇 |
1977年 | 66篇 |
1976年 | 56篇 |
1975年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 探讨不同时期慢性阻塞性肺疾病(COPD)患者血清诱饵受体3(DcR3)、凋亡抑制蛋白(Survivin)表达水平及临床意义。方法 选取2018年9月—2019年12月本院收治的92名COPD患者为研究对象,其中稳定型COPD 50例,急性加重期COPD 42例;同期本院健康体检者88例为对照组。测定各组研究对象血清DcR3、Survivin水平及肺功能指标。 与对照组[DcR3(106.54±48.35)pg/mL,Survivin(98.85±26.59)pg/mL]比较,稳定期组和急性加重期组血清DcR3[(395.23±123.85)pg/mL,(1 248.81±213.59)pg/mL]、Survivin [(267.54±84.69)pg/mL,(1 233.95±307.26)pg/mL]水平升高;与稳定期组比较,急性加重期组血清DcR3、Survivin水平升高。与对照组比较,稳定期组和急性加重期组FEV1%、FEV1 /FVC、DLCO%水平降低(P<0.001);与稳定期组比较,急性加重期组FEV1%、FEV1 /FVC、DLCO%水平降低(P<0.001)。随着低氧血症严重程度的增加,COPD患者血清DcR3、Survivin水平逐渐增加(P<0.001)。多因素logistics回归分析显示,高水平DcR3、Survivin、IL-12、hs-CRP为COPD病情的危险因素(P<0.001)。DcR3、Survivin与FEV、FEV1 /FVC呈负相关,与IL-12、TNF-α、hs-CRP呈正相关(P<0.001)。 COPD稳定期、急性加重期患者血清DcR3、Survivin表达水平升高,且DcR3、Survivin与COPD病情严重程度呈正相关。 相似文献
2.
《Transfusion and apheresis science》2022,61(4):103421
BackgroundTherapeutic plasma exchange (TPE) is an extracorporeal treatment that can be used in adult and pediatric patients with acute demyelinating syndromes of the central nervous system. In this study, the efficacy and safety of TPE was evaluated in 10 pediatric patients who underwent TPE that were unresponsive to corticosteroid treatment.MethodsRecords of 10 pediatric patients who underwent TPE in our pediatric intensive care unit (PICU) between May 2017 and June 2020 were used. Expanded Disability Status Scale (EDSS), Gait Scale (GS), and Visual Outcome Scale (VOS) were applied to the patients before and after TPE.ResultsOf the 10 patients who underwent TPE, five were diagnosed with multiple sclerosis (MS), three with transverse myelitis (TM), and two with acute disseminated encephalomyelitis (ADEM). The median age of the patients was 13.3 years (IQR 8-15), and the median day from symptom onset to onset of TPE was 12.5 days (IQR 7-28). A total of 104 TPE sessions were performed successfully. While no complications were encountered in three patients during the sessions, the most common complication was hypofibrinogenemia. The decrease in EDSS and GS scores was found to be consistent with the clinical response of the patients. There was no statistically significant decrease in the VOS.ConclusionsWith this study, we can say that TPE is a feasible, effective, and safe treatment modality in children with acute demyelinating syndromes of the central nervous system. 相似文献
3.
《Obstetrics, Gynaecology and Reproductive Medicine》2022,32(8):179-187
Continuous utero-placental circulation, and patent umbilical blood vessels ensure an uninterrupted transfer of oxygen and nutrients to the fetus as well as clearance of metabolic waste products. The onset of labour characterized by progressive and strong uterine contractions poses a threat to fetal oxygenation as a result of collapsing the spiral arterioles traversing the myometrium to supply the placental bed, and repetitive compression of the blood vessels within the umbilical cord. Human fetuses are equipped with compensatory mechanisms to cope with transient interruptions of blood supply during labour. The ability to compensate may be blunted in cases of poor fetal reserves, increased metabolic demand (macrosomia or maternal fever), and due to non-hypoxic pathways (e.g. chorioamniontis or fetal hypovolumia-hypotension syndrome). Intrapartum fetal surveillance involves prompt recognition of the features that signal the onset of fetal decompensation on the cardiotocograph (CTG) to ensure a timely intervention to avoid hypoxic-ischaemic encephalopathy (HIE) or perinatal deaths. This article summarises a ‘physiological approach’ to the interpretation of the CTG which, in places, conflicts with other current UK guidance. 相似文献
4.
5.
Anne-Sophie Worm Fenger Markus Harboe Olsen Maria Louise Fabritius Christian Gunge Riberholt Kirsten Møller 《Acta anaesthesiologica Scandinavica》2023,67(2):240-247
Background
Hyperglycaemia is common in patients with acute brain injury admitted to an intensive care unit (ICU). Many studies have found associations between development of hyperglycaemia and increased mortality in hospitalised patients. However, the optimal target for blood glucose control is unknown. We want to conduct a systematic review with meta-analysis and trial sequential analysis to explore the beneficial and harmful effects of restrictive versus liberal glucose control on patient outcomes in adults with severe acute brain injury.Methods
We will systematically search medical databases including CENTRAL, Embase, MEDLINE and trial registries. We will search the following websites for ongoing or unpublished trials: http://www.controlled-trials.com/ , http://www.clinicaltrials.gov/ , www.eudraCT.com , http://centerwatch.com/ , The Cochrane Library's CENTRAL, PubMed, EMBASE, Science Citation Index Expanded and CINAHL. Two authors will independently review and select trials and extract data. We will include randomised trials comparing levels of glucose control in our analyses and observational studies will be included to address potential harms. The primary outcomes are defined as all-cause mortality, functional outcome and health-related quality of life. Secondary outcomes include serious adverse events including hypoglycaemia, length of ICU stay and duration of mechanical ventilation, and explorative outcomes including intracranial pressure and infection. Trial Sequential Analysis will be used to investigate the risk of type I error due to repetitive testing and to further explore imprecision. Quality of trials will be evaluated using the Cochrane Risk of Bias tool, and quality of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.Discussion
The results of the systematic review will be disseminated through peer-reviewed publication. With the review, we hope to inform future randomised clinical trials and improve clinical practice. 相似文献6.
7.
目的 通过分析特发性肺纤维化急性加重期(AE-IPF)患者证候与血清生物标志物的关系,为中医辨证治疗提供参考。方法 采用观察性研究设计,收集2019年3月至2019年11月三个中心的AE-IPF患者76例,其中痰热壅肺证26例、痰浊阻肺证50例,并纳入健康志愿者10例作为对照。采用ELISA测定患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平,分析与中医证候的相关性。结果 AE-IPF患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平均显著高于健康对照组。血清CCL18、HMGB1、KL-6、MMP-7和SP-D水平在痰热壅肺证和痰浊阻肺证患者间无显著性差异(P>0.05),而血清SP-A水平存在显著性差异(P<0.05)。结论 血清SP-A与AE-IPF证候存在一定的相关性,血清SP-A的浓度升高,与痰热壅肺证关系越密切,反之,血清SP-A浓度降低,则与痰浊阻肺证关系越密切。AE-IPF痰热壅肺证患者的预后可能较痰浊阻肺证患者更差。 相似文献
8.
9.
《The Journal for Nurse Practitioners》2022,18(1):31-35
Acute coronary syndrome (ACS) remains one of the leading causes of death in the United States. With its heightened prevalence, considerable variabilities in the disease process exist across ethnicities, sex, and age. This creates substantial disparities in the recognition and management of ACS, which consequently contributes to poor outcomes. It is of utmost importance that nurse practitioners remain vigilant, cognizant, and maintain a high index of suspicion to accurately identify ACS presentations and thus efficaciously intervene to successfully manage the disease process. 相似文献
10.
目的 对中医药治疗特发性肺纤维化(idiopathic pulmonary fibrosis, IPF)的系统评价(SRs)进行再评价。方法 检索知网、中国生物医学数据库、维普、万方、The Cochrane Library、Web of Science、PubMed和EMbase数据库,纳入中医药治疗IPF的SRs,截止2021年5月。使用AMSTAR 2量表进行方法学质量评价,GRADE系统工具进行结局指标证据质量分级。结果 共纳入28篇文献,试验组除辨证论治外,治疗方法集中在活血化瘀、补肺益气等方面,基本符合治疗法则。结果显示中医药治疗IPF可以提高有效率、增加肺功能、提高PaO2、增加6WMD、缓解临床症状、提高患者的生活质量等。AMSTAR 2量表评价,所纳入SRs均有多项关键条目不达标,整体方法学质量等级不高。采用GRADE工具进行质量分级,一共234个结局指标,无高等证据质量,整体证据等级不高。结论 中医药对比西医治疗IPF有效且不良反应不明显,但RCT研究和系统评价研究方法质量尚有缺陷,完全按照西医评价指标可能会低估真实结果,未来需要更规范的研究及适合中医的评价指标,对中医药研究的安全性方面关注还有待提高。 相似文献