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   9104篇
  免费   720篇
  国内免费   180篇
耳鼻咽喉   119篇
儿科学   1143篇
妇产科学   251篇
基础医学   1766篇
口腔科学   455篇
临床医学   525篇
内科学   1246篇
皮肤病学   129篇
神经病学   1026篇
特种医学   444篇
外科学   1364篇
综合类   565篇
现状与发展   2篇
预防医学   169篇
眼科学   107篇
药学   230篇
  3篇
中国医学   97篇
肿瘤学   363篇
  2024年   16篇
  2023年   156篇
  2022年   289篇
  2021年   343篇
  2020年   323篇
  2019年   368篇
  2018年   320篇
  2017年   304篇
  2016年   319篇
  2015年   286篇
  2014年   600篇
  2013年   524篇
  2012年   355篇
  2011年   481篇
  2010年   401篇
  2009年   429篇
  2008年   421篇
  2007年   416篇
  2006年   345篇
  2005年   316篇
  2004年   270篇
  2003年   232篇
  2002年   191篇
  2001年   195篇
  2000年   195篇
  1999年   180篇
  1998年   192篇
  1997年   159篇
  1996年   154篇
  1995年   108篇
  1994年   99篇
  1993年   126篇
  1992年   110篇
  1991年   99篇
  1990年   59篇
  1989年   56篇
  1988年   57篇
  1987年   54篇
  1986年   45篇
  1985年   63篇
  1984年   49篇
  1983年   39篇
  1982年   39篇
  1981年   49篇
  1980年   46篇
  1979年   32篇
  1978年   28篇
  1977年   25篇
  1976年   14篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Spondyloepimetaphyseal dysplasias (SEMDs) belong to a clinically and genetically heterogeneous group of inherited skeletal disorders defined by a defect in the growth and shape of vertebrae, epiphyses and metaphyses. Rhizomelic SEMD is characterized by a disproportionate small stature caused by severe shortening and deformation of the limbs’ proximal bones, with the cranio-facial sphere unaffected. We report a second individual, an 8-year-old girl, with autosomal recessive rhizomelic SEMD associated with a homozygous exonic missense variant, c.226G > A p.(Glu76Lys), in GNPNAT1 identified by trio genome sequencing. Our data corroborate the recent findings of Ain et al. and further delineate the clinical and radiographic features of this form of SEMD associated with rhizomelic dysplasia while outlining a potential hotspot in this newly described genetic disorder.  相似文献   
2.
3.
PurposeTo evaluate the midterm outcomes of percutaneous transluminal renal angioplasty (PTRA) for pediatric renovascular hypertension (RVH).Materials and MethodsThe clinical data of patients who underwent PTRA for RVH in the authors’ hospital from 2012 to 2019 were retrospectively analyzed. Postprocedural blood pressure, glomerular filtration rate (GFR) of the affected kidney, restenosis, and complications were closely monitored.ResultsPTRA was performed in a total of 30 children (20 boys and 10 girls), with a mean age of 7.3 years ± 0.7 (range, 40 days to 13.9 years) and a mean weight of 25.0 kg ± 2.3 (range, 3.4–53 kg). The median follow-up period was 26.5 months (range, 1 month to 7.5 years). Technical success was achieved in 26 (86.7%) of the 30 patients. Restenosis developed in 3 patients (10.0%). Only 1 patient underwent stent implantation, and the stent fractured 8 months later, requiring further intervention. There were no other complications. In terms of clinical benefit of blood pressure control after the initial PTRA procedure, 15 patients (50%) were cured and 7 patients (23.3%) showed improvement. There was no significant difference in the etiology, lesion location, and lesion length between patients with clinical benefit and failure (P = .06, P = .202, and P = .06, respectively). GFR of the affected kidney was significantly improved from 19.9 mL/min ± 11.2 to 38.1 mL/min ± 11.9 at the 6-month follow-up after PTRA (P < .001).ConclusionsThe overall results of PTRA for pediatric RVH caused by different etiologies are promising. PTRA not only provided a clinical benefit of blood pressure control in 73.3% of the patients but also significantly improved the function of the affected kidney.  相似文献   
4.
5.
6.
《Clinical neurophysiology》2019,130(1):128-137
ObjectiveHigh frequency oscillations (HFO) between 80–500 Hz are markers of epileptic areas in intracranial and maybe also scalp EEG. We investigate simultaneous recordings of scalp and intracranial EEG and hypothesize that scalp HFOs provide important additional clinical information in the presurgical setting.MethodsSpikes and HFOs were visually identified in all intracranial scalp EEG channels. Analysis of correlation of event location between intracranial and scalp EEG as well as relationship between events and the SOZ and zone of surgical removal was performed.Results24 patients could be included, 23 showed spikes and 19 HFOs on scalp recordings. In 15/19 patients highest scalp HFO rate was located over the implantation side, with 13 patients having the highest scalp and intracranial HFO rate over the same region. 17 patients underwent surgery, 7 became seizure free. Patients with poor post-operative outcome showed significantly more regions with HFO than those with seizure free outcome.ConclusionsScalp HFOs are mostly located over the SOZ. Widespread scalp HFOs are indicative of a larger epileptic network and associated with poor postsurgical outcome.SignificanceAnalysis of scalp HFO add clinically important information about the extent of epileptic areas during presurgical simultaneous scalp and intracranial EEG recordings.  相似文献   
7.
8.
Sessile serrated adenoma/polyps (SSA/Ps) are early precursor lesions in the serrated neoplasia pathway, which results in BRAF‐mutated colorectal carcinomas with not only high levels of microsatellite instability but also microsatellite stable. SSA/Ps with advanced histology, including cytological dysplasia or minimally invasive carcinomas, are important lesions because SSA/Ps are considered major contributors to “interval cancers” and these lesions can rapidly become dysplastic or invasive carcinomas. Clinicopathologically, SSA/Ps with dysplasia or invasive carcinoma were associated with advanced age, female sex, and proximal colon. Although SSA/Ps with submucosal invasive carcinoma were smaller and invaded less deeply into the submucosal layer than conventional tubular adenomas with submucosal invasive carcinoma, SSA/Ps with submucosal invasive carcinoma frequently had a mucinous component and exhibited a higher potential for lymphatic invasion and lymph node metastasis. In an SSA/P series, endoscopic characteristics, including (semi)pedunculated morphology, double elevation, central depression, and reddishness, may help accurately diagnose SSA/Ps with advanced histology. Removal of SSA/Ps with dysplasia or invasive carcinoma was recommended. Endoscopic treatment such as endoscopic mucosal resection or endoscopic submucosal dissection is useful for those lesions. However, surgical resection with lymph node dissection might be indicated when SSA/Ps with invasive carcinoma are endoscopically suspected, because these have the high risk of lymph node metastasis. Greater awareness may promote further research into improving the detection, recognition, and complete resection rates of SSA/Ps with dysplasia or invasive carcinoma and reduce the interval cancer rates.  相似文献   
9.
BackgroundWe compared the short-term oncologic and functional outcomes of salvage focal cryotherapy (SFC) with those of salvage total cryotherapy (STC) for radiotherapy (RT)-persistent/recurrent prostate cancer.Materials and MethodsWe queried the Cryo On-Line Database registry for men who had undergone SFC and STC of the prostate for RT-persistent or recurrent disease. Propensity score weighting was used to match age at treatment, presalvage therapy prostate-specific antigen level, Gleason sum, and presalvage cryotherapy androgen deprivation therapy status. The primary outcome was progression-free survival.ResultsA total of 385 men with biopsy-proven persistent or recurrent prostate cancer after primary RT were included in the present study. The median follow-up, age, prostate-specific antigen, and Gleason sum before salvage cryotherapy was 24.4 months (first and third quartile, 9.8 and 60.3), 70 years (first and third quartile, 66 and 74 years), 4 ng/dL (first and third quartile, 2.7 and 5.6 ng/dL), and 7 (first and third quartile, 6 and 8), respectively. After propensity score weighting, the difference in progression-free survival was not statistically significant between the patients who had undergone STC and those who had undergone SFC (79.8% vs. 76.98%; P = .11 on weighted log-rank test). SFC was associated with a lower probability of post-treatment transient urinary retention (5.6% vs. 22.4%; P < .001). No significant differences were found in the incidence of rectal fistula (1.4% vs. 3.8; P = .30), new-onset urinary incontinence within 12 months (9.3% vs. 15.1%; P = .19), or new-onset erectile dysfunction within 12 months (52.6% vs. 59.6%; P = .47) between the SFC and STC groups, respectively.ConclusionsSTC resulted in similar 2-year oncologic outcomes compared with SFC in the RT-persistent/recurrent disease population. However, the patients who had undergone SFC had a lower urinary retention rate compared with those who had undergone STC.  相似文献   
10.
Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia.Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[14C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections.Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g− 1 min− 1 existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 ± 21 mm3 (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct.Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution.  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