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   11077篇
  免费   613篇
  国内免费   224篇
耳鼻咽喉   24篇
儿科学   263篇
妇产科学   184篇
基础医学   1043篇
口腔科学   66篇
临床医学   1765篇
内科学   1570篇
皮肤病学   85篇
神经病学   1242篇
特种医学   68篇
外国民族医学   1篇
外科学   311篇
综合类   1498篇
一般理论   1篇
预防医学   1738篇
眼科学   44篇
药学   1427篇
  3篇
中国医学   362篇
肿瘤学   219篇
  2024年   15篇
  2023年   140篇
  2022年   302篇
  2021年   376篇
  2020年   358篇
  2019年   392篇
  2018年   392篇
  2017年   312篇
  2016年   325篇
  2015年   323篇
  2014年   669篇
  2013年   860篇
  2012年   604篇
  2011年   636篇
  2010年   495篇
  2009年   542篇
  2008年   530篇
  2007年   515篇
  2006年   436篇
  2005年   312篇
  2004年   310篇
  2003年   256篇
  2002年   207篇
  2001年   198篇
  2000年   199篇
  1999年   158篇
  1998年   177篇
  1997年   163篇
  1996年   144篇
  1995年   145篇
  1994年   139篇
  1993年   112篇
  1992年   96篇
  1991年   107篇
  1990年   108篇
  1989年   71篇
  1988年   91篇
  1987年   75篇
  1986年   68篇
  1985年   123篇
  1984年   100篇
  1983年   55篇
  1982年   59篇
  1981年   57篇
  1980年   42篇
  1979年   33篇
  1978年   20篇
  1977年   26篇
  1976年   17篇
  1975年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
This study was conducted to investigate the hypocholesterolemic effect of simvastatin (30 mg/kg BW) and antioxidant effect of coenzyme Q10 (CoQ10, 15 mg/kg BW) or green tea (5%) on erythrocyte Na leak, platelet aggregation and TBARS production in hypercholesterolemic rats treated with statin. Food efficiency ratio (FER, ADG/ADFI) was decreased in statin group and increased in green tea group, and the difference between these two groups was significant (p<0.05). Plasma total cholesterol was somewhat increased in all groups with statin compared with control. Plasma triglyceride was decreased in statin group and increased in groups of CoQ10 and green tea, and the difference between groups of statin and green tea was significant (p<0.05). Liver total cholesterol was not different between the control and statin group, but was significantly decreased in the group with green tea compared with other groups (p<0.05). Liver triglyceride was decreased in groups of statin and green tea compared with the control, and the difference between groups of the control and green tea was significant (p<0.05). Platelet aggregation of both the initial slope and the maximum was not significantly different, but the group with green tea tended to be higher in initial slope and lower in the maximum. Intracellular Na of group with green tea was significantly higher than the control or statin group (p<0.05). Na leak in intact cells was significantly decreased in the statin group compared with the control (p<0.05). Na leak in AAPH treated cells was also significantly reduced in the statin group compared with groups of the control and CoQ10 (p<0.05). TBARS production in platelet rich plasma was significantly decreased in the groups with CoQ10 and green tea compared with the control and statin groups (p<0.05). TBARS of liver was significantly decreased in the group with green tea compared with the statin group (p<0.05). In the present study, even a high dose of statin did not show a cholesterol lowering effect, therefore depletion of CoQ10 following statin treatment in rats is not clear. More clinical studies are needed for therapeutic use of CoQ10 as an antioxidant in prevention of degenerative diseases independent of statin therapy.  相似文献   
22.
对负压吸引装置便携方式的研究一直是急救医学追求的目标之一,因为它能够极大地促进急救成功率。文章基于这种需要,研制了一套便携式负压吸引装置,并根据实际应用效果,选择优化的制造材料。研制的便携式负压吸引装置主要由特殊设计的储液罐及罐盖、负压产生装置、过渡接头等部分组成,关键部件采用特殊材料制作,体积小,质量轻,操作简单,易于携带,完全能满足临床抢救及治疗的需要。作为一种急救中必不可少的器械,便携式负压吸引装置在急救伤病员运输、转运,家庭急救,及无动力源环境等情况下,对于抢救患者及提高救治效果,具有极大的竞争优势和应用前景。  相似文献   
23.
高中一年级学生抑郁情绪及相关因素的研究   总被引:1,自引:0,他引:1  
目的调查高中一年级学生的抑郁情绪及与其个性、心理健康水平、应对能力和家庭环境的关系。方法采用整群抽样方法和问卷式调查,共调查高一学生488名,资料填写完整者449人(92.01%)。结果449名高一学生SDS平均得分(标准分)为(47.27±10.86),抑郁情绪的发生率为37.86%,不同性别和文理科之间差异无统计学意义。抑郁情绪组性格内向、情绪稳定性差和精神质表现较为突出,其SCL-90的9个因子评分均高于对照组,个人积极应对能力和解决问题的能力差,消极应对和自责表现突出,家庭的亲密度、情感表达、娱乐性和组织性均较对照组差,矛盾性较对照组突出。结论抑郁情绪已是高一学生中较为常见而且需要关注的心理卫生问题,严重影响其心身健康发展,抑郁情绪与个性、心理健康评分、个人应对方式和家庭环境均具有显著关系。  相似文献   
24.
Heparin-induced Extracorporeal LDL-Precipitation (HELP) is an effective procedure for the elimination of both plasma LDL and fibrinogen. In 10 adult patients with severe type II hyperlipoproteinemia, a single HELP treatment of 3 1 plasma led to an acute decrease in the average plasma viscosity (PV) from 1.30 to 1.1 mPas. At the same time, an even more marked decrease in the mean erythrocyte aggregation rate from a pathological value of 7.9% to a value of 3.7% (normal range less than 5%) was observed. Long-term studies on five patients demonstrated a lasting improvement in these two haemorheological variables. The acute rheological changes were also accompanied by an improvement in polarographically determined muscle oxygen tension. Mean oxygen tension values measured in both the m.biceps brachii and the m.tibialis anterior in five patients before and after a single HELP treatment increased from 30 +/- 4 to 37 +/- 7 mmHg and from 27 +/- 2 to 31 +/- 3 mmHg respectively. These results may provide an explanation for the rapid improvement in patients' clinical symptoms such as angina pectoris and in stress electrocardiogram which have been observed during HELP therapy.  相似文献   
25.
26.
学习成绩、家庭环境对学龄儿童自我意识的影响   总被引:2,自引:1,他引:1  
目的探讨学习成绩、家庭环境对儿童自我意识的影响。方法采用经验评估法、家庭环境量表和Piers Harris儿童自我意识量表对 9.5~ 12岁 2 87名儿童的学习成绩、家庭环境和自我意识进行评定。结果自我意识总分学习困难组 ( 5 8.76± 11.0 1) <学习中等组 ( 64 .5 9± 7.87) <学习优秀组 ( 69.80± 7.5 1) ,家庭环境量表中的亲密度、情感表达、矛盾性、知识性、娱乐性和控制性 6个因素与自我意识相关。结论学习成绩、家庭环境对学龄儿童自我意识的形成和发展起重要的作用 ,改善家庭环境、提高学习成绩 ,可有利于儿童自我意识的发展。  相似文献   
27.
陈汉英 《中国学校卫生》2006,27(12):1049-1050
目的探讨西部少数民族儿童行为问题及其与父母养育方式的关系,为少数民族地区开展心理健康教育提供理论依据。方法采用Achenbach儿童行为量表(CBCL)和儿童抚养行为问卷(CRPR)对415名苗族、土家族和侗族儿童进行调查。结果行为问题检出率为29.63%,其中男童为29.94%,女童为29.25%。男童检出率较高的因子为强迫、抑郁、交往不良、分裂样,女童检出率较高的因子为抑郁、分裂样强迫、多动。男童行为问题的绝大多数因子与父母的拒绝、惩罚定向呈显著的正相关,女童行为问题的多数因子与父母的拒绝呈显著正相关。结论黔东地区少数民族儿童行为问题显著高于全国水平,父母教养方式影响儿童的行为问题。  相似文献   
28.
本文报道1株抑制型抗人血小板单克隆抗体 SZ—47。SZ—47能完全抑制 ADP 及肾上腺素诱导的血小板聚集;而对花生四烯酸,瑞斯托霉素诱导的血小板聚集无影响;对胶原诱导的血小板聚集无明显抑制作用。因此,推测单克隆抗体 SZ—47主要通过 ADP 途径来影响血小板的聚集功能。  相似文献   
29.
Risk Factors for a First Febrile Seizure: A Matched Case-Control Study   总被引:10,自引:6,他引:4  
Summary We conducted a matched casecontrol study to identify risk factors for first febrile seizures, with special emphasis on characteristics of the acute illness episode. Cases were identified through hospital emergency departments; controls were identified through outpatient clinics and emergency departments. Sixtynine children with first febrile seizures and no history of previous unprovoked seizures were matched for age (±6 months), site of routine pediatric care, and date of visit (±weeks) with 1 or 2 febrile controls who had no history of previous febrile or unprovoked seizures. Medical records for the index visit were reviewed, and parents were interviewed by telephone. Illness characteristics examined included height of temperature, type of underlying illness, contact with a physician during the illness but before the index visit, and use of acetaminophen or decongestants. Family history of febrile and of unprovoked seizures, sociodemographic characteristics, daycare use, and selected preand perinatal variables were also studied. On multivariable analysis, significant independent risk factors were height of temperature, history of febrile seizures in a firstor in a higher degree relative. Gastroenteritis as the underlying illness had a significant inverse (i.e., protective) association with febrile seizures. Maternal smoking during pregnancy was a marginally significant predictor of febrile seizures.  相似文献   
30.
This paper reviews evidence from clinical, epidemiologic, and family studies regarding the association between social phobia and other syndromes. Social phobia is strongly associated with other anxiety disorders, substance abuse, and affective disorders in both clinical and community samples. An average of 80% of social phobics identified in community samples meet diagnostic criteria for another lifetime condition. Social phobia is most strongly associated with other subtypes of anxiety disorders, with an average of 50% of social phobics in the community reporting a concomitant anxiety disorder including another phobic disorder, generalized anciety, or panic disorder. Approximately 20% of subjects in the community meet lifetime criteria for a major depressive disorder. The onset of social phobia generally precedes that of all other disorders, with the exception of simple phobia. Both clinical severity and treated prevalence are consistently greater among social phobics with comorbid disorders The results of family and twin studies reveal that shared etiologic factors explain a substantial proportion of the comorbidity between social phobia and depression, whereas the association between social phobia and alcoholism derives from a nonfamilial causal relationship between the two conditions. Clinical and phenomenologic implications of these findings 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