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   1195篇
  免费   53篇
  国内免费   50篇
耳鼻咽喉   8篇
儿科学   35篇
妇产科学   12篇
基础医学   154篇
口腔科学   25篇
临床医学   126篇
内科学   295篇
皮肤病学   11篇
神经病学   106篇
特种医学   174篇
外科学   76篇
综合类   17篇
预防医学   23篇
眼科学   75篇
药学   110篇
肿瘤学   51篇
  2023年   4篇
  2022年   5篇
  2021年   20篇
  2020年   17篇
  2019年   13篇
  2018年   24篇
  2017年   13篇
  2016年   15篇
  2015年   19篇
  2014年   40篇
  2013年   33篇
  2012年   53篇
  2011年   52篇
  2010年   32篇
  2009年   56篇
  2008年   41篇
  2007年   58篇
  2006年   39篇
  2005年   26篇
  2004年   26篇
  2003年   31篇
  2002年   24篇
  2001年   29篇
  2000年   20篇
  1999年   30篇
  1998年   56篇
  1997年   47篇
  1996年   40篇
  1995年   33篇
  1994年   25篇
  1993年   36篇
  1992年   25篇
  1991年   24篇
  1990年   14篇
  1989年   37篇
  1988年   28篇
  1987年   29篇
  1986年   18篇
  1985年   22篇
  1984年   18篇
  1983年   18篇
  1982年   15篇
  1981年   16篇
  1980年   19篇
  1979年   8篇
  1978年   10篇
  1977年   7篇
  1976年   9篇
  1975年   4篇
  1974年   6篇
排序方式: 共有1298条查询结果,搜索用时 15 毫秒
81.
82.
The immunohistochemical and histochemical properties of 16 surgically excised subretinal neovascular membranes from 16 patients with age-related macular degeneration were studied. Primary antisera to c-retinaldehyde-binding protein; leukocyte common antigen; factor VIII-related antigen; S-100 protein; glial fibrillary acid protein; muscle-specific actin; neuron-specific enolase; collagen types I, II, III, IV, and V; laminin; and fibronectin were used for immunohistochemical characterization of the membranes. Histochemical staining for lipid and mucopolysaccharide was performed. The results of the staining in conjunction with histologic examination showed the cellular components of the membranes to be composed of retinal pigment epithelium, inflammatory cells, vascular endothelium, glial cells, myofibroblasts, photoreceptor cells, and fibrocytes. The extracellular matrix of the membranes contained collagen types I, III, IV, and V; fibronectin; laminin; mucopolysaccharide; and lipid. These findings are consistent with the concept that subretinal neovascular membranes in age-related macular degeneration are composed of localized intra-Bruch's membrane granulation tissue proliferation associated with diffuse drusen.  相似文献   
83.
Pathogenetic mechanisms in anterior proliferative vitreoretinopathy.   总被引:6,自引:0,他引:6  
A clinicopathologic study of ten consecutive patients (ten eyes) undergoing surgery for rhegmatogenous retinal detachment with anterior proliferative vitreoretinopathy and a subsequent histopathologic, immunohistochemical, and ultrastructural study of ten enucleated eyes with anterior proliferative vitreoretinopathy were performed in order to elucidate relevant pathogenetic mechanisms. Our findings suggest that the pathogenetic evolution of anterior proliferative vitreoretinopathy occurs in three consecutive stages: (1) traction on the ciliary body and peripheral retina induced by fibrocellular contraction of the vitreous base; (2) incorporation of tractionally denuded components of the ciliary body and peripheral retina into the fibrocellular membranes overlying the vitreous base; and (3) proliferation of the incorporated components and fibrovascular ingrowth from the uvea, the retina, or both, into the fibrocellular membranes. Tractional disruption of the epithelium of the ciliary body pars plicata and breakdown of the ciliary blood-aqueous barrier are the principal pathogenetic mechanisms of chronic intractable hypotony and the post-vitrectomy fibrin syndrome in anterior proliferative vitreoretinopathy.  相似文献   
84.
85.
86.
Wooden foreign bodies in soft tissue: detection at US   总被引:4,自引:0,他引:4  
  相似文献   
87.
Latency differences (>0.5 ms) of median and ulnar sensory action potentials (mSAP and uSAP) at the wrist evoked by ring finger stimulation are considered a sensitive and specific test for diagnosis of carpal tunnel syndrome (CTS). In this study, we aimed to assess the practical usefulness of the ring finger test (RFT) in routine electromyography (EMG) examinations. We investigated 2 series of patients: in the first prospective series we considered 300 hands affected by only mild CTS; in the second series we examined retrospectively the EMG charts of 961 hands affected only by CTS but not selected for severity or duration of symptoms. In the first series we found pathological RFT scores in 87% of cases, and pathological RFT or mSAP latency results in 92%. In the second series, pathological RFT scores were found only in 55% of cases, while in 20% where mSAP failed, a volume conducted uSAP had been erroneously interpreted as arising from the median nerve. RFT sensitivity tested in routine EMG examinations of unselected hands affected by CTS drops considerably. Fingers innervated by one only nerve, such as the index and the little fingers, must also be investigated to increase the diagnostic value of RFT.
Sommario La differenza (>0.5 ms) tra le latenze distali dei potenziali sensitivi di mediano e ulnare (mSAP e uSAP) registrati al polso ed evocati per stimolazione al quarto dito (ring finger test, RTF) viene considerato un test sensibile e specifico per la diagnosi di sindrome del tunnel carpale (CTS). Sono state studiate 2 serie di pazienti: nella prima serie prospettica abbiamo esaminato 300 mani affette da CTS lieve, in cui mSAP e uSAP dopo stimolazione al quarto dito potevano essere chiaramente differenziati. Il RFT era patologico nell'87%. Considerando insieme il risultato del RFT e il valore assoluto della latenza distale del mSAP dal quarto dito, almeno uno dei test era patologico nel 92% dei casi. Nella seconda serie sono stati esaminati retrospettivamente i referti EMG di 961 mani non selezionate affette esclusivamente da CTS. Attraverso il solo RFT solo il 55% delle diagnosi sarebbero state classificate correttamente, perchè in 20% un uSAP volume condotto era stato erroneamente interpretato come proveniente dal mediano. Dita innervate da un solo nervo come il secondo dito ed it quinto dito devono essere esaminate per aumentare il valore diagnostico del RFT in esami di routine.
  相似文献   
88.
Emphysema in the renal allograft   总被引:1,自引:0,他引:1  
Two diabetic patients in whom emphysematous pyelonephritis developed after renal transplantation are described. Clinical recognition of this unusual and serious infection is masked by the effects of immunosuppression. Abdominal radiographic, ultrasound, and computed tomography findings are discussed. The clinical presentation includes urinary tract infection, sepsis, and acute tubular malfunction of the allograft in insulin-dependent diabetics.  相似文献   
89.
The objective of our study was to evaluate the sociodemographic factors associated with completion of screening for latent tuberculosis infection (LTBI) among undocumented immigrants in Brescia, Italy. Screening for LTBI was offered to 649 immigrants; 213 (33%) immigrants completed the first step of screening; only 44% (55/124) of individuals with a positive tuberculin skin test result started treatment for LTBI. The univariate analysis showed that being unmarried, of Senegalese nationality and being interviewed by a health-care worker with the same native language as the immigrant were significantly associated with completion of screening for LTBI. In the multiple logistic regression, being interviewed in the native language of the health-care worker (OR 2.5, 95% CI 1.3-4.8, P = 0.004) and being of Senegalese origin (OR 2.3, 95% CI 1.4-3.6, P = 0.0005) were independently associated with adherence to LTBI screening. Our results suggest that knowledge of the sociodemographic characteristics of immigrants, and the participation of health-care workers of the same cultural origin as the immigrant during the visits, can be an important tool to improve completion of screening for LTBI.  相似文献   
90.
OBJECTIVES: To determine the effect of deep-plane rhytidectomy on the cross-sectional area of the nasal cavity in the vicinity of the nasal valves and to compare this quantitative measure with patients' subjective assessment of their postoperative nasal airway. DESIGN: An inception cohort of 17 patients undergoing rhytidectomy (either cheek-lift or face-lift) for facial rejuvenation was evaluated with acoustic rhinometry. Initial measurements were taken approximately 1 week prior to surgery, followed by postoperative measurements at 1 week and again at 1 month (a total of 18 measurements per patient). Patients undergoing simultaneous nasal procedures were excluded. Control subjects consisted of patients undergoing facial plastic procedures other than rhytidectomy or septorhinoplasty (n = 3). The main outcome measure was cross-sectional area of both the internal and external valve regions as determined by acoustic rhinometry. The setting was an ambulatory surgery center at a large academic institution. RESULTS: Seventy percent of patients (12 of 17) reported subjective improvement of their nasal airway patency following rhytidectomy, whereas no control subjects (0%) reported any such change. Eighty-eight percent of patients (15 of 17) had a substantial increase in the dimension of their internal nasal valve area as measured with acoustic rhinometry at 1 week, with 70% of patients demonstrating increase at 1 month. Fifty-three percent of patients (9 of 17) demonstrated an increase in their external valve area at 1 week, and 59% had a persistent increase as measured at 1 month. No control subjects demonstrated any significant nasal valve area increases at either time. There was no correlation between age or body mass index and the measurement outcomes among participants. CONCLUSIONS: While there is a statistically significant increase in both the internal and external nasal valve cross-sectional areas at 1 month after rhytidectomy, the permanency of this effect is unknown. In support of these findings, a sizable proportion of patients undergoing rhytidectomy subjectively report an increase in their ability to breathe through their noses, lending credence to a postrhytidectomy melonasal effect.  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