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   476710篇
  免费   31759篇
  国内免费   9473篇
耳鼻咽喉   4763篇
儿科学   12532篇
妇产科学   7989篇
基础医学   38574篇
口腔科学   9866篇
临床医学   56715篇
内科学   62396篇
皮肤病学   5443篇
神经病学   26741篇
特种医学   12606篇
外国民族医学   37篇
外科学   48814篇
综合类   74347篇
一般理论   39篇
预防医学   47052篇
眼科学   9051篇
药学   43347篇
  533篇
中国医学   41334篇
肿瘤学   15763篇
  2023年   7451篇
  2022年   10642篇
  2021年   16962篇
  2020年   17647篇
  2019年   21981篇
  2018年   19362篇
  2017年   17247篇
  2016年   14179篇
  2015年   13474篇
  2014年   28602篇
  2013年   30872篇
  2012年   25993篇
  2011年   28645篇
  2010年   23205篇
  2009年   20997篇
  2008年   20631篇
  2007年   21357篇
  2006年   18885篇
  2005年   16420篇
  2004年   13524篇
  2003年   11823篇
  2002年   9603篇
  2001年   8677篇
  2000年   7150篇
  1999年   6125篇
  1998年   4928篇
  1997年   4773篇
  1996年   4119篇
  1995年   4216篇
  1994年   4057篇
  1993年   3195篇
  1992年   3185篇
  1991年   2738篇
  1990年   2417篇
  1989年   2178篇
  1988年   2078篇
  1987年   1790篇
  1986年   1653篇
  1985年   4799篇
  1984年   5829篇
  1983年   4027篇
  1982年   4694篇
  1981年   4283篇
  1980年   3803篇
  1979年   3465篇
  1978年   2988篇
  1977年   2274篇
  1976年   2567篇
  1975年   1910篇
  1974年   1636篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
阻塞性睡眠呼吸暂停低通气综合症(obstructive sleep apnea hypopnea syndrome,OSAHS)是一种常见的睡眠障碍性疾病,长期的呼吸暂停和低通气可引起不同程度的低氧血症及高碳酸血症,继发组织缺氧,最终导致多器官功能损害,其中包括第8对颅神经-听神经的损害。临床观察中也发现了部分OSAHS患者出现了听力下降、耳鸣症状。本文在前人研究的基础上主要从四方面阐述OSAHS对听觉系统的损害:中耳压力的变化、胃食道反流对中耳的影响、缺氧对传导通路的损害、快速眼动时期(The rapid eye movement period,REM)剥夺引起微环境的改变。  相似文献   
2.
目的探析中高频听力下降型突发性聋采取耳后注射甲强龙治疗的临床效果及可行性。方法选取2019年5月~2020年7月本院耳鼻喉科就诊的中高频听力下降型突发性聋患者,共纳入病例54例,以随机法分组,即常规组(n=27)和观察组(n=27),常规组予常规治疗,观察组采取耳后注射甲强龙,比较两组效果。结果观察组有效率相比于常规组显著提高(P<0.05);治疗3周后,观察组2000~8000Hz频率听力提高值与常规组比(P<0.05)。结论中高频听力下降型突发性聋采取耳后注射甲强龙治疗效果理想,值得推广。  相似文献   
3.
4.
Tympanic membranes (TM) that have healed spontaneously after perforation present abnormalities in their structural and mechanical properties; i.e., they are thickened and abnormally dense. These changes result in a deterioration of middle ear (ME) sound transmission, which is clinically presented as a conductive hearing loss (CHL). To fully understand the ME sound transmission under TM pathological conditions, we created a gerbil model with a controlled 50% pars tensa perforation, which was left to heal spontaneously for up to 4 weeks (TM perforations had fully sealed after 2 weeks). After the recovery period, the ME sound transmission, both in the forward and reverse directions, was directly measured with two-tone stimulation. Measurements were performed at the input, the ossicular chain, and output of the ME system, i.e., at the TM, umbo, and scala vestibuli (SV) next to the stapes. We found that variations in ME transmission in forward and reverse directions were not symmetric. In the forward direction, the ME pressure gain decreased in a frequency-dependent manner, with smaller loss (within 10 dB) at low frequencies and more dramatic loss at high frequency regions. The loss pattern was mainly from the less efficient acoustical to mechanical coupling between the TM and umbo, with little changes along the ossicular chain. In the reverse direction, the variations in these ears are relatively smaller. Our results provide detailed functional observations that explain CHL seen in clinical patients with abnormal TM, e.g., caused by otitis media, that have healed spontaneously after perforation or post-tympanoplasty, especially at high frequencies. In addition, our data demonstrate that changes in distortion product otoacoustic emissions (DPOAEs) result from altered ME transmission in both the forward and reverse direction by a reduction of the effective stimulus levels and less efficient transfer of DPs from the ME into the ear canal. This confirms that DPOAEs can be used to assess both the health of the cochlea and the middle ear.  相似文献   
5.
6.
7.
IntroductionOur aim was to describe practices in multimodal pain management at US children's hospitals and evaluate the association between non-opioid pain management strategies and pediatric patient-reported outcomes (PROs).MethodsData were collected as part of the 18-hospital ENhanced Recovery In CHildren Undergoing Surgery (ENRICH-US) clinical trial. Non-opioid pain management strategies included use of preoperative and postoperative non-opioid analgesics, regional anesthetic blocks, and a biobehavioral intervention. PROs included perioperative nervousness, pain-related functional disability, health-related quality of life (HRQoL). Associations were analyzed using multinomial logistic regression models.ResultsAmong 186 patients, 62 (33%) received preoperative analgesics, 186 (100%) postoperative analgesics, 81 (44%) regional anesthetic block, and 135 (73%) used a biobehavioral intervention. Patients were less likely to report worsened as compared to stable nervousness following regional anesthetic block (relative risk ratio [RRR]:0.31, 95% confidence interval [CI]:0.11–0.85), use of a biobehavioral technique (RRR:0.26, 95% CI:0.10–0.70), and both in combination (RRR:0.08, 95% CI:0.02–0.34). There were no associations of non-opioid pain control modalities with pain-related functional disability or HRQoL.ConclusionUse of postoperative non-opioid analgesics have been largely adopted, while preoperative non-opioid analgesics and regional anesthetic blocks are used less frequently. Regional anesthetic blocks and biobehavioral interventions may mitigate postoperative nervousness in children.Level of evidenceIII.  相似文献   
8.
BackgroundPerianal abscesses and anal fistulas are common. The principle of intention-to-treat has not been considered in previous systemic reviews. Thus, the comparison between primary and post-recurrence management was confused, and the recommendation of primary treatment is obscure. The current study aims to identify the optimal initial treatment for pediatric patients.MethodsUsing PRISMA guidelines, studies were identified from MEDLINE, EMBASE, PubMed, Cochrane Library, and Google Scholar without any language or study design restriction. The inclusion criteria include original articles or articles with original data, studies of management for a perianal abscess with or without anal fistula, and patient age of <18 years. Patients with local malignancy, Crohn's disease, or other underlying predisposing conditions were excluded. Studies without analyzing recurrence, case series of <5, and irrelevant articles were excluded in the screening stage. Of the 124 screened articles, 14 articles had no full texts or detailed information. Articles written in a language other than English or Mandarin were translated by Google Translation first and confirmed with native speakers. After the eligibility process, studies that compared identified primary managements were then included in the qualitative synthesis.ResultsThirty-one studies involving 2507 pediatric patients met the inclusion criteria. The study design consisted of two prospective case series of 47 patients and retrospective cohort studies. No randomized control trials were identified. Meta-analyses for recurrence after initial management were performed with a random-effects model. Conservative treatment and drainage revealed no difference (Odds ratio [OR], 1.222; 95% Confidential interval [CI]: 0.615–2.427, p = 0.567). Conservative management had a higher risk of recurrence than surgery without statistical significance (OR 0.278, 95% CI: 0.109–0.707, p = 0.007). Compared with incision/drainage, surgery can prevent recurrence remarkably (OR 4.360, 95% CI: 1.761–10.792, p = 0.001). Subgroup analysis of different approaches within conservative treatment and operation was not performed for lacking information.ConclusionStrong recommendations cannot be made due to the lack of prospective or randomized controlled studies. However, the current study based on real primary management supports initial surgical intervention for pediatric patients with perianal abscesses and anal fistula to prevent recurrence.Level of evidenceType of study: Systemic review; Evidence level: Level II.  相似文献   
9.
ObjectiveThe use of mechanical circulatory support (MCS) in lung transplantation has been steadily increasing over the prior decade, with evolving strategies for incorporating support in the preoperative, intraoperative, and postoperative settings. There is significant practice variability in the use of these techniques, however, and relatively limited data to help establish institutional protocols. The objective of the AATS Clinical Practice Standards Committee (CPSC) expert panel was to review the existing literature and establish recommendations about the use of MCS before, during, and after lung transplantation.MethodsThe AATS CPSC assembled an expert panel of 16 lung transplantation physicians who developed a consensus document of recommendations. The panel was broken into subgroups focused on preoperative, intraoperative, and postoperative support, and each subgroup performed a focused literature review. These subgroups formulated recommendation statements for each subtopic, which were evaluated by the entire group. The statements were then developed via discussion among the panel and refined until consensus was achieved on each statement.ResultsThe expert panel achieved consensus on 36 recommendations for how and when to use MCS in lung transplantation. These recommendations included the use of veno-venous extracorporeal membrane oxygenation (ECMO) as a bridging strategy in the preoperative setting, a preference for central veno-arterial ECMO over traditional cardiopulmonary bypass during the transplantation procedure, and the benefit of supporting selected patients with MCS postoperatively.ConclusionsAchieving optimal results in lung transplantation requires the use of a wide range of strategies. MCS provides an important mechanism for helping these critically ill patients through the peritransplantation period. Despite the complex nature of the decision making process in the treatment of these patients, the expert panel was able to achieve consensus on 36 recommendations. These recommendations should provide guidance for professionals involved in the care of end-stage lung disease patients considered for transplantation.  相似文献   
10.
Protein-energy wasting (PEW) and poor health-related quality of life (HRQoL) are independently associated with morbi-mortality in continuous ambulatory peritoneal dialysis (CAPD). PEW may reduce HRQoL; however, we hypothesized HRQoL is affected differentially by PEW degrees or by individual criteria of nutritional status.AimTo evaluate HRQoL according to PEW severity and nutritional status indicators in CAPD.This is a cross-sectional study in 151 patients. Subjective global assessment (SGA) was employed, and nutritional status classified as normal, mild-moderate PEW, and severe PEW. HRQoL was evaluated using Kidney Disease Quality of Life Short Form?, including physical (PCS), mental (MCS) and kidney disease (KDCS) components, and their subscales. Dietary intake, anthropometric and biochemical variables were measured.Forty-six percent of patients were well-nourished, 44% had mild-moderate PEW, and 10% severe PEW. Compared with well-nourished patients, those with mild-moderate (p = 0.06) and severe (p = 0.005) PEW had lower HRQoL score [68 (52–75), 55 (45–72), 46 (43–58), respectively]. PCS, MCS, and KDCS and their subscales had lower values as PEW was more severe. Patients with obesity and hypoalbuminemia had significantly lower HRQoL overall and component scores than their counterparts. Dietary intake was not associated with quality of life. In multivariate analysis obesity, PEW (by SGA), hypoalbuminemia, and low educational level predicted poor HRQoL (χ2 58.2, p < 0.0001).As conclusion, PEW severity was related with worse HRQoL, either as overall score or in every component or subscale in CAPD patients. Poor HRQoL was predicted independently by PEW severity and obesity; additional predictors were hypoalbuminemia and low education.  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