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   10350篇
  免费   378篇
  国内免费   67篇
耳鼻咽喉   5篇
儿科学   568篇
妇产科学   358篇
基础医学   539篇
口腔科学   11篇
临床医学   1353篇
内科学   839篇
皮肤病学   42篇
神经病学   170篇
特种医学   243篇
外科学   2732篇
综合类   1330篇
预防医学   1019篇
眼科学   4篇
药学   962篇
  6篇
中国医学   290篇
肿瘤学   324篇
  2023年   104篇
  2022年   267篇
  2021年   318篇
  2020年   283篇
  2019年   286篇
  2018年   307篇
  2017年   272篇
  2016年   280篇
  2015年   313篇
  2014年   740篇
  2013年   648篇
  2012年   708篇
  2011年   774篇
  2010年   538篇
  2009年   555篇
  2008年   486篇
  2007年   521篇
  2006年   429篇
  2005年   368篇
  2004年   346篇
  2003年   240篇
  2002年   217篇
  2001年   175篇
  2000年   160篇
  1999年   136篇
  1998年   125篇
  1997年   87篇
  1996年   91篇
  1995年   98篇
  1994年   79篇
  1993年   71篇
  1992年   66篇
  1991年   58篇
  1990年   85篇
  1989年   59篇
  1988年   60篇
  1987年   50篇
  1986年   33篇
  1985年   40篇
  1984年   34篇
  1983年   13篇
  1982年   34篇
  1981年   39篇
  1980年   25篇
  1979年   27篇
  1978年   30篇
  1977年   22篇
  1976年   26篇
  1975年   14篇
  1973年   13篇
排序方式: 共有10000条查询结果,搜索用时 781 毫秒
71.
Obstructed voiding is a well recognized complication following a suburethral sling procedure. Current methods of transvaginal and transabdominal urethrolysis have had variable success rates in relieving the obstruction, and do not restabilize the urethra to prevent potential postoperative stress incontinence. We report on a procedure used in 4 cases which addresses both of these issues. All patients had persistent urinary retention beyond 8 weeks after a suburethral sling procedure. An oupatient procedure consisting of sling incision and associated tissue interposition (vaginal wall in three cases and fascia lata in one) was successful in relieving the obstruction. Continence status was maintained in 3 of the 4 patients. There were no major complications of this outpatient procedure.  相似文献   
72.
  Variability in the interpretation of micturating cystourethrography by paediatric radiologists for the diagnosis of vesicoureteric reflux in children was evaluated. All 265 micturating cystourethrograms (MCUs) that were available from 304 consecutive children aged 0.5 – 61 months  –  who were investigated after their first urine infection between 1993 and 1995 as part of a prospective cohort study  –  were selected for interpretation. Three experienced paediatric radiologists from the same department independently interpreted the MCUs according to the grading system of the International Reflux Study in Children, from grades 0 to V, with the presence of intrarenal reflux also noted. Apart from being informed that urine infection was the indication for the MCU, no other clinical information was given to the radiologists. The indices of variability used were the percentage of agreement and the kappa statistic, expressed as a percentage. Both measures were weighted with integers representing the number of categories from perfect agreement. Disagreement was analysed for children and kidneys. For the diagnosis of vesicoureteric reflux in individual patients, including grade, the percentage of agreement was 96% – 97% (kappa 90% – 91%) and the weighted percentage of agreement was 96% – 98% (weighted kappa 93% – 94%). The same high level of agreement was present for individual kidneys, with a percentage of agreement of 97% – 98% (kappa 89% – 92%) and a weighted percentage of agreement of 98% – 99% (kappa 94% – 95%). There was near perfect agreement in the interpretation of radiological micturating cystourethrography among three experienced paediatric radiologists for the diagnosis and grade of vesicoureteric reflux. Any variations in the medical care of children suspected of having vesicoureteric reflux are not explained by differences in the reporting of this diagnostic test. Received June 19, 1996; received in revised form November 1, 1996; accepted December 6, 1996  相似文献   
73.
改良Indiana膀胱术的远期疗效观察   总被引:1,自引:1,他引:0  
目的:评价改良Indiana膀胱术的远期疗效.方法:对26例改良Indiana膀胱术术后患者的膀胱可控性、尿动力学、肾盂输尿管扩张、上尿路感染情况、血清电解质和肾功能进行随访.结果:26例随访1~7年,平均3年.白天可控率96.2%;贮尿囊容量为380~640 ml,平均542 ml;贮尿囊内压力为1.215~3.224 kPa,平均1.921 kPa.B超、IVP造影示3 例输尿管扩张,经随访无加重.血清电解质及肾功能正常.结论:改良Indiana膀胱术远期疗效可靠,并发症少,是一种较理想的尿路分流术式.  相似文献   
74.
无张力阴道吊带术治疗压力性尿失禁(附10例报告)   总被引:7,自引:0,他引:7  
目的探讨无张力阴道吊带术(TVT)的手术方法、适应证及并发症的预防. 方法女性压力性尿失禁(SUI)患者10例,平均年龄52岁.漏尿病史平均7年,其中8例为轻中度SUI,加压期尿道压力>10 cmH2O,2例为重度SUI,加压期尿道压力<10 cmH2O.经阴道前壁行无张力阴道吊带术. 结果 10例SUI均得到满意的控尿效果.1例患者术后剩余尿100 ml,但主观评价明显改善.随访13~21个月,无SUI症状复发,无排尿困难及尿路感染. 结论 TVT是一种简便、快捷的SUI治疗方法,疗效满意,可以减少患者的痛苦和缩短住院时间.  相似文献   
75.
尿液分析标准化在临床上的应用   总被引:1,自引:0,他引:1  
目的:建立尿液分析的标准化。方法:NCCLS和CCCLS推荐方法。结果:按标准化的要求进行尿液分析,以获得有临床价值的结果。结论:尿液分析是临床最常用的化验指标之一,在临床诊治疾病中起着非常重要的作用,因此在实际工作中必须遵照标准化的操作规程进行操作,更好地为临床服务。  相似文献   
76.
Summary Mechanisms for maintaining passive continence in the efferent limb of urinary diversions include compression of tissue, peristalsis, equilibration of pressure and use of valves. Motor activity and pressure in the ileum, ileocecal valve (ICV) and the colon were evaluated in dogs. Spontaneous activity and pressure were compared with stimulated pressure response and activity. Stimulation was performed at the pelvic nerve and the small nerves in the mesenterium, as well as direct neurostimulation of the bowel. Resting pressure at the ICV was 12.7±0.4 cmH2O rising to 26.4±2.2 cmH2O during spontaneous depolarization. Stimulation of the pelvic nerve resulted in increased colonic motor activity with unchanged pressure. Electric stimulation of small mesenterical nerves to the ICV increased pressure in the ICV to 35.0±4.1 cmH2O, while direct myoelectric stimulation of the ICV zone increased the intraluminal pressure to 75.0±3.2 cmH2O. Termination of the electric stimulation was followed by a slow decrease of pressure to the resting level a period of 30–45 s. Maintaining continence at the ICV with long-term constant or intermittent stimulation seems feasible.  相似文献   
77.
Summary The surfaces of 32 encrusted urinary catheters were examined by scanning electron microscopy to investigate the association of bacteria with the encrusting deposits. Deposits consisted of struvite crystals surrounded by aggregates of very small crystallites of hydroxyapatite. Underneath these minerals there was a layer of closely packed bacteria. Impressions of bacteria were also observed in hydroxyapatite. Crystals were often engulfed by the bacterial layer, which thus appeared to bind the crystals to each other and to the catheter surface. This thick layer of bacteria associated with crystals may protect both the bacteria from antibiotics and the crystals from acidic bladder washout solutions intended to dissolve them. Furthermore, the existence of this sessile population explains why urease-producing bacteria are not invariably detected in the urine of patients with encrusted catheters. The observation of this bacterial layer (or biofilm) by scanning electron microscopy provided direct evidence for infection being implicated in catheter encrustation.  相似文献   
78.
To assess the characteristics of connective tissue metabolism in chronic renal failure (CRF), urinary excretion of glycosaminoglycan (GAG) fractions and hydroxyproline (HYP) was determined in ten patients with CRF and in ten age-matched healthy children. CRF was found to be associated with elevated free HYP (19.9±6.1 vs 9.8±3.6 mol/day,P<0.05) and depressed peptide HYP excretion (33.1±13.5 vs 225.2±17.7 mol/day,P<0.01), a low rate of total GAG excretion (7.0±2.4 vs 16.1±1.9 mol uronic acid/day,P<0.05) with low chondroitin 4 — sulphate + chondroitin 6 — sulphate (Ch-Ss) (14.0±9.9 vs 65.0±22.1%) and a high proportion of non-sulphated or under-sulphated fractions, i.e. hyaluronic acid + chondroitin + heparan sulphate (HA+Ch+HS) (75.3±11.4 vs 31.5±5.7%). Urinary 3-methyl-histidine (3-met-HIS) excretion and plasma essential free amino acids did not differ in the two groups. In response to haemodialysis no consistent change occurred in urinary excretion of 3-met-HIS, peptide-bound HYP, total GAG or percentage distribution of individual GAG fractions. After haemodialysis all plasma amino acids decreased significantly, and there was a significant increase in urinary excretion of free HYP (P<0.05). We conclude that the alterations in urinary excretion of total and individual GAGs observed in CRF may reflect disturbed connective tissue metabolism which does not appear to be accounted for by protein malnutrition or enhanced protein breakdown and remains uninfluenced by haemodialysis therapy.  相似文献   
79.
Summary Subjective symptoms related to autonomic dysfunction and quantitative non invasive tests measuring both sympathetic and parasympathetic functions of the autonomic nervous system were studied among a group of 41 chlorine-alkali workers with low long-term exposure to mercury (Hg') vapour and their matched referents. The test battery included measurements of pulse rate variation in normal and deep breathing, in the Valsalva manoeuvre and in vertical tilt as well as blood pressure responses during standing and isometric work. The exposure time had been 16 years on average, and the mean exposure to Hg vapour was estimated to have been about 30 g/m3 of air. Only a tendency for a subtle reduction of cardiovascular reflex responses and a slight increase of subjective symptoms were seen in the exposed group, but no significant autonomic dysfunction was associated with the low level of exposure.  相似文献   
80.
The acute biochemical effects of the nephrotoxin p-aminophenol (PAP) were studied in detail using a combination of conventional bioanalytical and 1H-NMR spectroscopic methods. Dosing PAP (25–100 mg/kg) to male F344 rats resulted in a dose-related proximal nephropathy with consequent elevations in urinary enzymes, glucose, and urine total protein as shown by conventional methodology. 1H-NMR spectroscopy at 400 MHz of urine from PAP-treated rats also revealed a characteristic glycosuria, with concomitant amino aciduria. The increased excretion of these compounds indicates functional defects in the proximal tubule and reduced solute reabsorption efficiency. In addition, 1H-NMR urinalysis and conventional enzymatic analysis showed a dose-related lactic aciduria. Other changes detected by 1H-NMR included a dose-related reduction in the excretion of citrate (confirmed by a conventional biochemical method) and an increase in the excretion of acetate. The degree of abnormalities shown by 1H-NMR urinalysis agreed well with histopathological observations and conventional biochemical indices of nephrotoxicity. 1H-NMR urinalysis therefore serves to highlight changes in the excretion of low MW urine components not routinely studied by conventional biochemical analysis.Abbreviations ALP alkaline phosphatase - APAP paracetamol - BUN blood urea nitrogen - GFR glomerular filtration rate - GOT glutamate oxaloacetate transaminase - LAP leucine aminopeptidase - LDH lactate dehydrogenase - MW molecular weight - NAG N-acetyl--D-glucosaminidase - PAP p-aminophenol - ppm parts per million - TMAO trimethylamine N-oxide - UFR urine flow rate  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