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   5011370篇
  免费   398088篇
  国内免费   16023篇
耳鼻咽喉   71622篇
儿科学   158571篇
妇产科学   133823篇
基础医学   747695篇
口腔科学   143399篇
临床医学   456105篇
内科学   913179篇
皮肤病学   116938篇
神经病学   422284篇
特种医学   199451篇
外国民族医学   1270篇
外科学   754966篇
综合类   147680篇
现状与发展   23篇
一般理论   2885篇
预防医学   423206篇
眼科学   119950篇
药学   357926篇
  24篇
中国医学   12831篇
肿瘤学   241653篇
  2021年   56425篇
  2019年   59050篇
  2018年   75190篇
  2017年   57528篇
  2016年   64192篇
  2015年   76854篇
  2014年   111766篇
  2013年   177266篇
  2012年   137830篇
  2011年   144620篇
  2010年   129195篇
  2009年   130215篇
  2008年   131594篇
  2007年   140618篇
  2006年   148911篇
  2005年   143503篇
  2004年   144509篇
  2003年   134384篇
  2002年   124886篇
  2001年   190721篇
  2000年   188817篇
  1999年   170794篇
  1998年   75996篇
  1997年   71133篇
  1996年   69006篇
  1995年   64800篇
  1994年   58890篇
  1993年   54634篇
  1992年   129699篇
  1991年   124698篇
  1990年   119769篇
  1989年   116432篇
  1988年   108292篇
  1987年   106643篇
  1986年   101428篇
  1985年   99017篇
  1984年   80855篇
  1983年   71394篇
  1982年   53435篇
  1981年   49340篇
  1980年   46411篇
  1979年   73424篇
  1978年   57009篇
  1977年   49716篇
  1976年   46470篇
  1975年   46674篇
  1974年   54040篇
  1973年   51918篇
  1972年   48623篇
  1971年   44995篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
We describe a mild form of drug-induced pemphigus in a woman with essential arterial hypertension treated with captopril. Complete recovery was observed three weeks after the therapy had been discontinued.  相似文献   
992.
993.
为了观察一般剂量补钙对缺氧缺血性脑病(HIE)脑细胞和红细胞内外钙变化的影响,以探讨HIE时补钙是否增加脑细胞钙超载,用HIE新生动物模型进行了实验研究,结果表明:(1)缺氧缺血时红细胞、脑细胞及脑组织出现钙积聚;(2)补钙后,血浆总钙浓度明显升高,而脑细胞、脑组织及红细胞钙积聚并未加重;(3)血浆总钙浓度与脑细胞或红细胞胞浆游离钙离子浓度无相关关系。提示:(1)HIE时钙内流可能是全身性的;(2)对HIE并低钙血症患儿吸氧后一般剂量补钙可能是安全的。  相似文献   
994.
Abstract Resilient adolescents are notable for their social competence, which enables them to form and maintain close relationships. The evidence is that adolescents' social competence is derived from their experience of close relationships within their family. On the basis of structured interviews, adolescents' working models of attachments can be categorized into secure, dismissive, or pre-occupied. These attachment styles are associated with very divergent beliefs about the self and others, with differing patterns of emotion regulation and with differing risk profiles for maladjustment. Parenting styles and family relationships appear to have considerable influence on attachment behaviour. Further evidence for the importance of the family comes from research on ego development. Family level behavioural patterns have been discerned from family research interviews which are associated with stagnation or advancement in ego development during adolescence. Though the results suggest causal connections, the direction of effects is far from clear. Longitudinal research underpins the importance of childhood temperament as a contributing factor to the quality of the family environment that the child and then adolescent experiences.  相似文献   
995.
996.
Monohalogenated methanes (methyl chloride, methyl bromide and methyl iodide) are mutagenic and carcinogenic. The possible mechanism of these effects, DNA methylation, was studied. DNA adducts from orgnas of F344 rats exposed to these chemicals were separated and identified with high performance liquid chromatography (HPLC) and gaschro-matography/massspectrometry (GC/ MS). DNA adducts, 7-methylguanine (7-MeG) and O6-Methylguanine(08-MeG), incorporation of14C into de novo synthesis of nucleobases could be observed in enzymatic DNA hydrolysates by HPLC and determination of the radioactivity in the fractions. The formation of DNA add,ue,ts in the studied organs was only quantitatively different. The formation of O6-MeG was further pioved by analysing the acidic hydrolysates using HPLC with non-radioactive O6MeG as internal standard. 7-MeG and 3-MeA were identified with GC/MS analysis.  相似文献   
997.
Summary We have investigated whether the pharmacokinetics and pharmacodynamics of the ACE inhibitor benazepril hydrochloride are altered with proteinuria by studying 8 patients with major proteinuria of different causes who were given a single dose of 10 mg p.o.The maximum plasma concentration of benazepril was found between 0.5 and 2 h after dosing (median 1 h). Its elimination was almost complete within 6 h. Peak plasma levels of benazeprilat, the active metabolite of benazepril, were observed between 1 and 6 h (median 2.5 h). The elimination of benazeprilat from plasma was biphasic, with mean initial and terminal half-lives of 3.0 and 17.3 h, respectively. On average, the pharmacokinetic parameters of benazepril and benazeprilat in the patients did not differ from those in a historical control group of healthy volunteers, but intersubject variability in the AUC and half-lives of benazeprilat was greater in the patients.Plasma ACE was completely inhibited from 1.5 to 6 h after dosing, and at 48 h the mean inhibition was still 42 %. Plasma renin showed substantial intersubject variation. Mean supine blood pressure (systolic/diastolic) was reduced from baseline by a maximum of 18/13 mm Hg at 6 h. Proteinuria was diminished after benazepril in 7 patients.In conclusion, the results of this study suggest that proteinuria in the nephrotic range does not require a change in benazepril dosage.  相似文献   
998.
Summary A randomised crossover study was performed in subjects with rheumatoid arthritis (or other arthropathies) to investigate if any alteration in the steady pharmacokinetics of the NSAID piroxicam (a drug which is extensively metabolised via cytochrome P450) or its major metabolites occurred as a result of coadministering either cimetidine or nizatidine.Twelve females and 2 males with mean age, weight, and albumin concentrations of 58 years, 61 kg, and 40 g·L–1 respectively, completed the study. Comparisons were made between the following parameters: plasma piroxicam AUCs [AUC0-24(P)], plasma 5-hydroxypiroxicam AUCs [AUC0-24(5-OHP)], the ratio of these i.e. AUC0-24(5-OHP):AUC0-24(p), the % piroxicam daily dose excreted in urine as 5-hydroxypiroxicam (before and after glucuronidase incubation); and the mean of the steady state trough piroxicam, and 5-hydroxypiroxicam concentrations (obtained during each study phase in addition to the wash-out period).A statistically significant difference as a result of initiating either cimetidine or nizatidine was obtained only for the ratio AUC0-23(5-OHP):AUC0-24(P). This was indicative of a weak potential to inhibit piroxicam hydroxylation.No clinically significant alteration in the steady state pharmacokinetics of piroxicam occurred in these subjects as a result of cimetidine or nizatidine coadministration. Consequently it is unlikely that any adverse events would arise from these combinations.  相似文献   
999.
1000.
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