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   5676篇
  免费   359篇
  国内免费   388篇
耳鼻咽喉   17篇
儿科学   30篇
妇产科学   23篇
基础医学   568篇
口腔科学   54篇
临床医学   725篇
内科学   619篇
皮肤病学   33篇
神经病学   174篇
特种医学   149篇
外国民族医学   3篇
外科学   382篇
综合类   1470篇
预防医学   609篇
眼科学   30篇
药学   860篇
  6篇
中国医学   418篇
肿瘤学   253篇
  2024年   1篇
  2023年   111篇
  2022年   220篇
  2021年   260篇
  2020年   295篇
  2019年   198篇
  2018年   189篇
  2017年   106篇
  2016年   223篇
  2015年   181篇
  2014年   451篇
  2013年   473篇
  2012年   687篇
  2011年   670篇
  2010年   456篇
  2009年   330篇
  2008年   216篇
  2007年   319篇
  2006年   206篇
  2005年   121篇
  2004年   95篇
  2003年   109篇
  2002年   110篇
  2001年   76篇
  2000年   61篇
  1999年   54篇
  1998年   44篇
  1997年   56篇
  1996年   42篇
  1995年   12篇
  1994年   5篇
  1993年   14篇
  1992年   9篇
  1991年   6篇
  1990年   3篇
  1989年   4篇
  1987年   4篇
  1986年   3篇
  1985年   1篇
  1984年   2篇
排序方式: 共有6423条查询结果,搜索用时 15 毫秒
1.
Percutaneous balloon mitral valvuloplasty (PBMV) is primarily performed for rheumatic mitral stenosis (MS). Therefore, limited data exist on PBMV in countries with a low incidence of rheumatic disease. Using the Nationwide Readmission Database, we examined trends in in-hospital mortality and 30-day readmission among patients who received PBMV for rheumatic and non-rheumatic MS. We also examined the change in 90-day hospitalization rate before vs after PBMV. Between 2016 and 2019, there were 1109 hospitalizations in which patients received PBMV for rheumatic (n = 955, 86.1%) vs non-rheumatic MS (n = 154, 13.9%). The all-cause in-hospital mortality for rheumatic and non-rheumatic MS did not change over time (0.9% → 2.0%, P = 0.94, and 5.9% → 9.5%, P = 0.09 respectively). Similarly, the 30-day readmission for patients with rheumatic and non-rheumatic MS did not change over time (12.4% → 9.9%, P = 0.26, and 4.4% → 10.5%, P = 0.30, respectively). The 90-day all-cause hospitalization rate remained the same before vs after PBMV for rheumatic and non-rheumatic MS (25.5% → 21.8%; P = 0.14, and 24.0% → 33.7%; P = 0.19, respectively). Although no statistically significant change was noted over time for trends in in-hospital mortality, 30-day readmission, or even in the change in 90-day all-cause hospitalizations before and after PBMV for both types of MS, among those with non-rheumatic MS, there was a signal of an increase in the in-hospital mortality, and 30-day readmission, even more, there was 29% relative increase in 90-day hospitalizations after PBMV. Future studies are needed to examine the role of PBMV in patients with non-rheumatic MS.  相似文献   
2.
目的研究分析连续护理干预模式对脊柱骨折伴脊髓损伤患者术后康复效果。方法本项研究回顾了2017年2月—2018年7月间在某院采取了脊柱骨折伴脊髓损伤治疗的52例患者整个治疗过程的资料,将所有的患者使用数字双盲法将其分为了对照组(n=26)和观察组(n=26)。对照组患者使用护理措施为常规护理措施,观察组使用的护理措施为连续护理干预模式,在患者治疗完成后对比两个不同组别患者在围手术期期间各类指标和出现并发症概率。结果对照组患者手术下床活动时间、住院时间、住院所需费用以及患者并发症发生率均显著高于观察组,组别间数据对比差异具有统计学意义(P<0.05)。结论医护人员在进行脊柱骨折伴脊髓损伤患者的护理工作当中,对其采取连续护理模式可以降低患者并发症发生率,缩短患者住院时间,对患者身体的恢复具有显著意义。  相似文献   
3.
Prolonged building closures are prevalent during the COVID-19 pandemic, resulting in extreme stagnation in building water systems. High-throughput sequencing analysis revealed significantly increased presence of Legionella due to extreme water stagnation, highlighting elevated exposure risks to Legionella from building water systems during re-opening of previously closed buildings.  相似文献   
4.
5.
Nilotinib is a specific breakpoint cluster region-Abelson leukemia virus-tyrosine kinase inhibitor that is used as an effective first- or second-line treatment in imatinib-resistant chronic myelogenous leukemia (CML) patients. Hepatotoxicity due to nilotinib is a commonly reported side effect; however, abnormal liver function test (LFT) results have been reported in asymptomatic cases. When alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels are more than five-fold the upper limit of the normal (ULN) or when the serum total bilirubin level is more than three-fold the ULN, dose modification or discontinuation of nilotinib is recommended, resulting in decreased levels of hematological indicators in certain patients with CML. Nilotinib-induced hyperbilirubinemia typically manifests as indirect bilirubinemia without elevated ALT or AST levels. Such abnormal liver functioning is thus not attributed to the presence of a true histologic lesion of the liver. The underlying mechanism may be related to the inhibition of uridine diphosphate glucuronosyltransferase activity. Therefore, nilotinib dose adjustment is not recommended for this type of hyperbilirubinemia, and in the absence of elevated liver enzyme levels or presence of abnormal LFT findings, physicians should consider maintaining nilotinib dose intensity without modifications.  相似文献   
6.
BackgroundExposure to adverse childhood experiences (ACEs) has been associated with both inflammation and depression. However, little research has examined the potential mediational role of inflammation in the link between ACEs and depression using longitudinal data. Therefore, we investigated the direct and indirect effects of ACEs on inflammation, depression, and their change trajectories over time.MethodsWe used data from the English Longitudinal Study of Ageing. Four ACE categories were assessed retrospectively at wave 3 (2006–07): abuse (physical or sexual abuse or physical assault), family dysfunction (parent arguments, parent mental illness or substance abuse, or parent separation or divorce), poor parent–child bonding (maternal or paternal), and loss of an attachment figure (separation from mother for >6 months, parent death, foster care or adoption, or institutionalisation). A cumulative ACE score was calculated representing the total number of ACEs experienced by the participants. Concentration of C-reactive protein (CRP), an inflammatory marker, was measured at waves 2 (2004–05), 4 (2008–09), and 6 (2012–13). Depressive symptoms were ascertained using the 8-item Centre for Epidemiological Studies Depression Scale from waves 6 to 8 (2016–17). The longitudinal direct and indirect effects of ACEs were estimated using parallel process latent growth curve modelling. All analyses were adjusted for relevant confounders. Missing data were estimated using multiple imputation.ResultsAmong the study sample (N=4382; mean age 70 years; 56% female), 24% of participants reported one ACE and 13% had two or three ACEs. The percentage of participants with three or more depressive symptoms was 21% at baseline. Greater cumulative exposure to ACEs was associated with increased CRP concentration (β=0·042, p=0·010) and depressive symptoms (β=0·164, p<0·0001) at baseline and predicted a steeper increase in these outcomes throughout the study (βCRP=0·074, p=0·011; βDepression=0·338, p<0·0001). However, indirect effects of ACEs on depression mediated by CRP were not observed, with only weak associations between CRP and depressive symptoms (βiDepression=0·032, p=0·173; βsDepression=0·067, p=0·240). Sensitivity analyses using only somatic depressive symptoms as the outcome revealed a positive association between CRP and somatic symptoms at baseline (βiDepression=0·068, p=0·008), although the indirect effects remained non-significant in this model.InterpretationBiological mechanisms other than inflammation might underlie the relationship between ACEs and depression. Psychosocial interventions to reduce the negative effects of ACEs on children's development could help to reduce the risk of depression and of other medical conditions linked to inflammation.FundingEconomic and Social Research Council–Biotechnology and Biological Sciences Research Council Soc-B Centre for Doctoral Training (ES/P000347/1).  相似文献   
7.
BackgroundPatients awaiting kidney transplantation are regularly screened for HLA-antibodies, but there is scarce data about the optimal interval.MethodsResults from Complement-dependent cytotoxicity testing (CDC) for waitlisted patients were reviewed for increases in panel reactive antibodies (PRA) by at least 10%-points. Clinical records were screened for historic immunizing events and possible trigger factors preceding the PRA-increase. Additionally, non-pretransplanted men tested negative for HLA antibodies by solid-phase assays (SPA) out of their first two samples on the waiting list (“non-immunized men”) were evaluated for detection of HLA antibodies by SPA during their further stay on the waiting list.Results15,360 samples from 1928 patients tested by CDC were analyzed for changes in PRA. PRA-increases occurred most frequently in patients waitlisted recently for retransplantation (annual incidence 6%). Removal of previous transplants, severe infections and/or reduced immunosuppression triggered 65% of PRA-increases during the first year after waitlisting. Transfusions accounted for 55% of PRA-increases in later years. Leucocyte-reduced red blood cell units not only boosted historic antibodies, but even induced primary immunization. In the second part of the study, 6780 samples tested by SPA from 703 non-immunized men were evaluated for development of HLA-antibodies. Only 9 men (1.3%) turned HLA antibody-positive (annual incidence 0.4%).ConclusionA uniform screening interval does not fit all: Frequencies should be highest in patients newly waitlisted for re-transplant and lowest in non-immunized men. Transfused patients should be monitored closely for development of HLA-antibodies even if leukoreduced products are used.  相似文献   
8.
BackgroundThis study aims to compare the use of one-per-mil tumescent solution (a mixture of epinephrine and 0.2% lidocaine in a ratio of 1:1,000,000 in normal saline solution) and tourniquet to create clear operative fields and to evaluate the functional outcomes after post burn hand contracture surgery.MethodsThe subjects of this randomized controlled trial were divided into one-permil tumescent technique and tourniquet group for a similar surgical procedure. Three independent assessors evaluated the clarity of the operative fields through recorded videos for the first 15 min and the first 10-minute of each hour of the surgery. Functional outcome was evaluated at least three months postoperatively using total active and passive motion (TAM and TPM) of each digit. Malondialdehyde (MDA) and tumor necrosis factor alpha (TNF-α) were tested during baseline (5 min before the procedures), ischemia phase, and reperfusion phase (a phase when the blood flow returned to the tissue).Results35 subjects were included in this study: 17 in the tumescent group and 18 in the tourniquet group. We found a significant difference in the clarity of operative field between tumescent and tourniquet groups, 5 vs 35 bloodless operative fields, respectively (p < 0.05). TAM and TPM of each digit before surgery and 3 months postoperatively showed no significant difference between both groups (p > 0.05). Furthermore, we found no difference in MDA and TNF-α levels between both groups at their respective phases.ConclusionsThe use of one-per-mil tumescent technique does not replace tourniquet use to create bloodless operative fields in burned hand contracture surgery. However, the postoperative functional results were similar in both groups showing that tumescent technique can be used as an alternative to tourniquet without compromising outcomes. The MDA and TNF-α examinations do not provide conclusive outcomes regarding ischemia and reperfusion injury.  相似文献   
9.
10.
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