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   35745篇
  免费   2745篇
  国内免费   381篇
耳鼻咽喉   138篇
儿科学   742篇
妇产科学   188篇
基础医学   4613篇
口腔科学   341篇
临床医学   3095篇
内科学   4229篇
皮肤病学   282篇
神经病学   467篇
特种医学   2435篇
外国民族医学   3篇
外科学   3997篇
综合类   4461篇
预防医学   1578篇
眼科学   144篇
药学   2364篇
  10篇
中国医学   808篇
肿瘤学   8976篇
  2024年   64篇
  2023年   442篇
  2022年   965篇
  2021年   1214篇
  2020年   1085篇
  2019年   962篇
  2018年   981篇
  2017年   1095篇
  2016年   1079篇
  2015年   1187篇
  2014年   2288篇
  2013年   2257篇
  2012年   1935篇
  2011年   2335篇
  2010年   1711篇
  2009年   1838篇
  2008年   1922篇
  2007年   1814篇
  2006年   1619篇
  2005年   1365篇
  2004年   1215篇
  2003年   1107篇
  2002年   925篇
  2001年   899篇
  2000年   829篇
  1999年   762篇
  1998年   604篇
  1997年   552篇
  1996年   469篇
  1995年   490篇
  1994年   406篇
  1993年   307篇
  1992年   300篇
  1991年   232篇
  1990年   210篇
  1989年   168篇
  1988年   153篇
  1987年   137篇
  1986年   105篇
  1985年   134篇
  1984年   141篇
  1983年   76篇
  1982年   91篇
  1981年   76篇
  1980年   88篇
  1979年   44篇
  1978年   56篇
  1977年   32篇
  1974年   24篇
  1973年   23篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
祝宇飞 《现代保健》2009,(35):10-11
目的初步探讨减瘤手术在晚期肺癌治疗方面的实用价值。方法选择2006年1月至2008年1月笔者所在医院收治的的中晚期肺癌患者20例,采用减瘤手术治疗。选择同时期15例剖胸探查肺肿物活检患者作为对照组。研究分析两组患者术后生存质量及生存时间的差异。结果减瘤组患者生存质量较好率为40.0%,对照组为20.0%,两组间比较差异有统计学意义(χ^2=7.21,P〈0.05)。生存质量评分减瘤组为(35.3±8.2)分,对照组为(27.9±7.1)分,两组间比较差异有统计学意义(t=6.59,P〈0.05)。平均生存时间减瘤组患者为11.6个月,对照组为10.3个月,两组间比较,差异无统计学意义(t=2.41,P〉0.05)。结论减瘤手术可改善中晚期或已有远处转移的肺癌患者的生存质量。  相似文献   
102.
Objective: The use of non-heart-beating donors (NHBD) has been propagated as an alternative to overcome the scarcity of pulmonary grafts. Formation of microthrombi after circulatory arrest, however, is a major concern for the development of reperfusion injury. We looked at the effect and the best route of pulmonary flush following topical cooling in NHBD. Methods: Non-heparinized pigs were sacrificed by ventricular fibrillation and divided into three groups (n = 6 per group). After 1 h of in situ warm ischaemia and 2.5 h of topical cooling, lungs in group I were retrieved unflushed (NF). In group II, lungs were explanted following an anterograde flush (AF) through the pulmonary artery with 50 ml/kg Perfadex® (6 °C). Finally, in group III, lungs were retrieved after an identical but retrograde flush (RF) via the left atrium. Flush effluent was sampled at intervals to measure haemoglobin concentration. Performance of the left lung was assessed during 60 min in our ex vivo reperfusion model. Wet-to-dry weight ratio (W/D) of both lungs was calculated as an index of pulmonary oedema. IL-1ß and TNF- protein levels in bronchial lavage fluid from both lungs were compared between groups. Results: Haemoglobin concentration (g/dl) was higher in the first effluent in RF versus AF (3.4 ± 1.1 vs 0.6 ± 0.1; p < 0.05). Pulmonary vascular resistance (dynes × s × cm−5) was 975 ± 85 RF versus 1567 ± 98 AF and 1576 ± 88 NF at 60 min of reperfusion (p < 0.001). Oxygenation (mmHg) and compliance (ml/cmH2O) were higher (491 ± 44 vs 472 ± 61 and 430 ± 33 NS, 22 ± 3 vs 19 ± 3 and 14 ± 1 NS, respectively) and plateau airway pressure (cmH2O) was lower (11 ± 1 vs 13 ± 1 and 13 ± 1 NS) after RF versus AF and NF, respectively. No differences in cytokine levels or in W/D ratios were observed between groups after reperfusion. Histology demonstrated microthrombi more often present after AF and NF compared to RF. Conclusion: Retrograde flush of the lung following topical cooling in the NHBD results in a better washout of residual blood and microthrombi and subsequent reduced pulmonary vascular resistance upon reperfusion.  相似文献   
103.
蛇毒治疗不能解释肺动脉高压的研究   总被引:1,自引:1,他引:0  
李超乾  梁国容 《广西医学》1997,19(6):943-945
本通过对不能解释的肺动脉高压患,进行右心导管测定肺动脉平均压(PAMP)作为主要对照指标,观察蛇毒制品(精制溶栓酶)的急性药物试验和近期药物试验。发现该药物在近期有理想的降低PAMP作用,症状及胸片、超声心动图异常也明显取得改善,提示其可能为治疗该病的理想药物。  相似文献   
104.
In order to obtain more information on the long-term effects of treatment of Wilm's tumour we investigated 30 subjects treated at the Children's Hospital between 1960 and 1976. All had been nephrectomized and in 4 the length of the remaining kidney was subnormal. In the other subjects kidney length was related to follow up time and age at follow up. Blood pressure was elevated in 5 subjects. Urinary albumin excretion deviated only slightly from normal. Tubular functions were well preserved in all subjects. In this small series we were unable to establish any relation between the abnormalities observed and the treatment given. Our results suggest that, despite wide interindividual variation those who survive Wilm's tumours seldom have long-term renal complications.  相似文献   
105.
A 7 1/2-year-old girl with an inflammatory pseudotumor of the lung is presented. The nature of the lesion was not recognized pre-or intraoperatively. The lesion was rubbery, yellowish, and well-defined but not encapsulated. Histologically, a spindle-cell lesion with a storiform pattern and chronic inflammatory-cell infiltrate was seen. The immunological and ultrastructural studies supported an inflammatory origin. The lesion corresponds to the fibrous histiocytoma variant of inflammatory pseudotumor of the lung, as defined recently by Matsubara et al. [17]. This must be distinguished from rare benign neoplasms of the lung such as benign fibrous histiocytoma, leiomyoma, Schwannoma, and histiocytosis.  相似文献   
106.
107.
杀菌性通透性增强蛋白对失血性休克的保护作用及其机理   总被引:2,自引:0,他引:2  
分别在失血和复苏开始即刻iv杀菌性/通透性增强蛋白(BPI)1.5和3.5mgkg-1,观察BPI对大鼠失血性休克转归的影响.结果显示,BPI治疗能明显改善失血性休克大鼠肝肾功能,提高休克动物存活率(BPI组81%vs休克对照组44%,P<0.05),BPI组大鼠复苏后与休克前的血浆内毒素(0.20±0.04vs0.24±0.05kUL-1)水平无明显变化,血浆肿瘤坏死因子α和白介素6水平较休克前明显升高,但均显著低于休克对照组.提示BPI对失血性休克大鼠具有一定的保护作用,其机理可能与BPI拮抗休克时内源性内毒素活性,抑制细胞因子反应有关.  相似文献   
108.
A follow-up investigation was performed on 49 female workers studied 2 years earlier in a vegetable-pickling plant. Acute and chronic respiratory symptoms and ventilatory capacity measurements were recorded during the original and the follow-up studies. Maximal expiratory flow-volume (MEFV) curves were recorded during the Monday morning work shift. The forced vital capacity (FVC), 1-s forced expiratory volume (FEV1), and flow rates at 50% and the last 25% of the FVC (FEF50, FEF25) were measured. There were small increases in the prevalence of chronic symptoms between the two studies for both smokers and nonsmokers, but these did not reach statistical significance. Five workers at the time of the initial study had a diagnosis of occupational asthma; only one of these was still working at the time of follow-up. Workers lost to the follow-up had lower lung function than those seen at follow-up. In workers who were followed, larger than expected mean annual declines were noted for all ventilatory capacity parameters in both smokers (FVC 0.070 l, FEV1 0.070 l; FEF50 0.355 l/s, FEF25 0.270 l/s) and nonsmokers (FVC 0.045 l, FEV1 0.045 l, FEF50 0.285 l/s; FEF25 0.130 l/s). The decrease was particularly pronounced for FEF50 and FEF25. The accelerated decline in ventilatory capacity tests noted in the female nonsmokers suggests an independent effect on lung function of work exposure in this environment. Our data confirm that work in the pickling industry, particularly in small, poorly regulated plants, has deleterious effects on respiratory function. Received: 24 September 1996 / Accepted: 19 June 1997  相似文献   
109.
陈书盘  耿沁 《肿瘤》1997,17(5):258-261
目的评价检测CYFRA21┐1对非小细胞肺癌的诊断价值。方法用ELISA法测定70例肺癌(LC)其中47例非小细胞肺癌(NSCLC),3例小细胞肺癌(SCLC)和20例未分型肺癌、64例肺部良性疾病患者及40例健康人血清CYFRA21┐1浓度。试验的诊断性能用相对操作特征(ROC)分析法估测之。结果测得全阈诊断准确率(OveralDiag┐nosticAccuracies)LC为0.75、NSCLC为0.76,SQC为0.83,ADE为0.67和SCLC为0.38。在相应于特异性为0.95的界定值3.47μg/L处,各型的灵敏度分别为SQC0.62,LC0.53,NSCLC0.51,ADE0.48和SCLC0.00。结论结果显示CYFRA21┐1是NSCLC较灵敏和特异的一个标志物。未观察到TNM各期间该标志物的平均水平有明显的差异;然而异常升高水平的患者的比例随病期的进展而显著增加,提示一系列检测CYFRA21┐1水平可能有助于监查NSCLC患者的疗效。  相似文献   
110.
Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum) is a rare pseudo-neoplastic disorder of the cerebellum with typical MRI findings. A 25-year-old man presenting with progressive neck pain, dizziness, and impaired vision is reported. CT and MRI revealed a left cerebellar haemispheric mass and obstructive hydrocephalus. Lhermitte-Duclos disease was histologically confirmed after surgical removal of the lesion. The typical MRI appearance of a nonenhancing haemispheric cerebellar mass with preservation and exaggeration of the normal gyral pattern allows pre-operative diagnosis of this condition. The literature is reviewed and clinical presentation, radiology and histopathology are discussed.  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