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   17152篇
  免费   2013篇
  国内免费   479篇
耳鼻咽喉   46篇
儿科学   1212篇
妇产科学   235篇
基础医学   1949篇
口腔科学   117篇
临床医学   2850篇
内科学   2708篇
皮肤病学   193篇
神经病学   1926篇
特种医学   450篇
外科学   1288篇
综合类   2579篇
现状与发展   1篇
预防医学   1419篇
眼科学   253篇
药学   1253篇
  6篇
中国医学   418篇
肿瘤学   741篇
  2024年   34篇
  2023年   276篇
  2022年   568篇
  2021年   881篇
  2020年   774篇
  2019年   782篇
  2018年   843篇
  2017年   883篇
  2016年   944篇
  2015年   858篇
  2014年   1425篇
  2013年   1264篇
  2012年   1173篇
  2011年   1183篇
  2010年   861篇
  2009年   823篇
  2008年   748篇
  2007年   755篇
  2006年   716篇
  2005年   507篇
  2004年   452篇
  2003年   418篇
  2002年   364篇
  2001年   306篇
  2000年   269篇
  1999年   196篇
  1998年   206篇
  1997年   171篇
  1996年   113篇
  1995年   90篇
  1994年   96篇
  1993年   84篇
  1992年   70篇
  1991年   64篇
  1990年   43篇
  1989年   53篇
  1988年   44篇
  1987年   34篇
  1986年   45篇
  1985年   49篇
  1984年   35篇
  1983年   18篇
  1982年   20篇
  1981年   24篇
  1980年   21篇
  1979年   17篇
  1978年   10篇
  1977年   12篇
  1976年   6篇
  1968年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Senile plaques in Alzheimer's disease (AD) are composed principally of Aβ, a 4 kDa fragment of the amyloid precursor protein (APP). Longer forms of APP which contain a Kunitz proteinase inhibitor (KPI) domain are elevated in aged and in AD brains. Tissue factor pathway inhibitor-1 (TFPI) contains three tandem KPI domains and has been well characterized for its role as a natural anticoagulant in the extrinsic coagulation pathway. Functionally, the first two KPI domains of TFPI bind and inhibit the activity of factor Xa and VIIa respectively. In addition, TFPI and APP-KPI share a common clearance mechanism through the low density lipoprotein receptor-related protein (LRP). As part of an ongoing study of the role of KPI-containing proteins in AD, the current study examines TFPI localization in the brain. We report here that TFPI is immunohistochemically localized to microglia in both AD and non-AD individuals and is localized to some senile plaques in AD. Western blot analyses indicate that the amount of TFPI is elevated in frontal cortex samples from AD brains. We propose that TFPI may play a cell specific role in proteinase regulation in the brain.  相似文献   
82.
目的 分析连续肾替代治疗 (continuousrenalreplacementtherapy,CRRT)对严重烧伤脓毒症患者血浆内毒素和细胞因子水平的影响。 方法 对 10例应用CRRT及 10例应用常规疗法治疗的严重烧伤脓毒症患者血浆内毒素和细胞因子 (TNFα、IL 1β、IL 6、IL 8)浓度变化进行比较分析。 结果 严重烧伤脓毒症患者应用CRRT后血浆内毒素、细胞因子浓度较治疗前明显下降 ,其下降速度与常规治疗组比较差异有非常显著性意义 (P <0 .0 1)。 结论 严重烧伤脓毒症患者应用CRRT能有效降低血浆内毒素和细胞因子浓度  相似文献   
83.
本文对27例新生儿缺氧缺血性脑病(HIE)在常规治疗基础上加用脑活素与常规治疗相比较,发现两组治疗结果在统计学上比较差异有显著性(P<0.05),提示脑活素对治疗HIE有一定疗效,可提高治愈率,减少后遗症的发生。  相似文献   
84.
目的研究产褥期脑病的临床特征、治疗方法及预后。方法选择62例产褥期突发精神症状并有全脑受累体征病人的临床资料进行回顾性分析。结果发现产褥期脑病的临床表现酷似病毒性脑炎,但病前无明显感染灶,病程较长,疗效和预后较差。结论对产褥期精神异常病人应进行神经病学方面检查,尽早诊治。病初要控制和缩短脑水肿期,防止和减轻脑细胞的变性和脱鞘;恢复期要耐心而持久地进行各种康复治疗,以便病人恢复到最佳健康水平。  相似文献   
85.
SUMMARY: A comparative immunohistological study was performed for the glomerular deposition of complements (C1q and C3c), fibrin/fibrinogen‐related antigen (FRA), the expression of intercellular adhesion molecule‐1 (ICAM‐1), and the infiltration of leucocytes bearing β2 integrins (leucocyte function associated antigen‐1 (LFA‐1), complement receptor 3 (CR3) and complement receptor 4 (CR4)) on renal biopsy specimens from 49 cases with Henoch‐Schoenlein purpura nephritis (HSPN), and 49 age‐matched cases with immunoglobulin A nephropathy (IgAN). the glomerular expression of ICAM‐1 was signifcantly correlated with the glomerular infiltration of leucocyte function associated antigen (LFA)‐1+ leucocytes in both diseases, and with that of CR3+ leucocytes in HSPN. the expression of ICAM‐1 was closely localized with the infiltration of LFA‐1+ leucocytes in the study with double immunostaining. the incidence and intensity of glomerular deposition of FRA were significantly higher in HSPN than in IgAN (P< 0.001), and those of C3c were significantly lower in HSPN than in IgAN (P< 0.001). the glomerular deposition of FRA was significantly correlated with the glomerular infiltration of CR4+ leucocytes in HSPN (P<0.05) but not in IgAN. In contrast, the glomerular deposition of C3c was significantly correlated with the glomerular infiltration of CR4+ leucocytes in IgAN (P<0.05), but not in HSPN. Studies with double immunostaining revealed a close association of CR4+ leucocytes with FRA deposition in HSPN and with C3c deposition in IgAN, respectively. the number of glomerular leucocytes bearing β2 integrins was significantly correlated with urinary protein at the time of renal biopsy in both diseases. These results suggested the differential roles of β2 integrins in the induction of glomerular injury in HSPN and IgAN. the ICAM‐1/LFA‐1 interaction may commonly be involved in the glomerular infiltration of leucocytes in both diseases. the ICAM‐1/CR3 interaction may be involved only in HSPN. Complement receptor 4 may function as a fibrin/fibrinogen receptor in HSPN, while CR4 may function as a complement receptor in IgAN.  相似文献   
86.
本文对西宁地区新生儿缺氧缺血性脑病(HIE)颅脑超声诊断分析脑缺氧缺血产生的原因、脑实质损伤程度及预后评估。提出对围产期窒息导致脑缺血性损害的预防措施。  相似文献   
87.
Twenty solvent-exposed workers, most of them painters, had been diagnosed as cases of toxic encephalopathy in 1978/79. Two years later they were re-examined with an extensive battery of neuropsychological tests. Their performance was unchanged on retesting. We have now compared their test results with those of non-exposed control subjects. Previous impressions of significant intellectual impairment in the solvent-exposed patients could not be confirmed when the influence of age, education, and intelligence was taken into consideration. The present group with presumed toxic encephalopathy is assumed to be representative of other patients who were similarly diagnosed in our department. The presently reanalyzed cases had been diagnosed as brain damaged and reported as such in the literature. Thus, they may have contributed to the formation of the concept of the "chronic painters' syndrome" with dementia.  相似文献   
88.
目的:探讨生物标志物联合检测对脓毒症相关急性肝损伤患者的早期诊断和预后评估的价值。方法:收集内蒙古科技大学包头医学院第一附属医院重症医学科(ICU)2019年11月-2022年1月收治的104例脓毒症患者临床资料,按照入ICU时是否发生急性肝损伤分为脓毒症相关急性肝损伤组(n=42)和非肝损伤组(n=62),将脓毒症相关急性肝损伤患者按28 d是否存活分为存活组(n=16)和死亡组(n=26),记录104例患者入ICU 6 h内血清正五聚蛋白3(PTX-3)、C-反应蛋白(CRP)、降钙素原(PCT)、总胆红素(TBIL)、谷草转氨酶(AST)、谷丙转氨酶(ALT)、凝血酶原时间国际标准化比值(INR值)、凝血酶原时间(PT)、凝血酶原活动度(PTA)、血小板(PLT)、入ICU 24 h内急性生理与慢性健康状况评估量表II(APACHEII)评分最差值及序贯器官衰竭评估(SOFA)评分;同时记录脓毒症相关急性肝损伤患者28 d预后。PTX-3的相关性采用Spearman相关分析;绘制受试者工作特征曲线(ROC曲线),计算ROC曲线下面积(AUC),分析各指标单独检测以及联合检测对脓毒...  相似文献   
89.
In an attempt to develop a short neuropsychological test battery five different tests of reaction time were assessed according to their ability to discriminate between HIV seropositive men and healthy controls. In all tests a patient group with clinical symptoms was slower than the control group. In the complex reaction time test, which has a large cognitive aspect, even a clinically "asymptomatic" group was slower than the control group. The movement test, a new test with a large motor component, identified most slow responders, defining approximately half of the patients with clinical symptoms and one third of the "asymptomatic" patients as such. A test battery consisting of three tests is suggested for serial assessment and screening.  相似文献   
90.
目的 探讨胃癌组织中HpcagA菌株感染对IL-8蛋白表达的影响。方法 采用流式细胞技术,对27例胃癌及相应的癌旁正常组织中IL-8蛋白的表达进行定量检测,用PCR法,对27例胃癌组织中HpcagA基因进行扩增。结果 27例胃癌组织中中,有25例(92%)可明显表达IL-8蛋白;而相应的癌旁正常组织中,基本没有IL-8蛋白的表达或仅有弱相应的癌旁正常组织中,基本没有IL-8蛋白的表达或仅有弱表达,HpcagA感染的胃癌组织中,IL-8的表达水平为64.27%,高于未感染HpcagA的胃癌组织(39.86%)。结论 IL-8在胃癌组织中的高表达与HpcagA感染有关。即HpcagA菌株感染可上调IL-8在胃癌组织中的表达水平。  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