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   8571篇
  免费   430篇
  国内免费   43篇
耳鼻咽喉   99篇
儿科学   148篇
妇产科学   133篇
基础医学   943篇
口腔科学   398篇
临床医学   683篇
内科学   2446篇
皮肤病学   64篇
神经病学   426篇
特种医学   244篇
外科学   1492篇
综合类   35篇
预防医学   231篇
眼科学   107篇
药学   567篇
中国医学   8篇
肿瘤学   1020篇
  2023年   43篇
  2022年   71篇
  2021年   124篇
  2020年   63篇
  2019年   71篇
  2018年   109篇
  2017年   99篇
  2016年   137篇
  2015年   154篇
  2014年   175篇
  2013年   192篇
  2012年   368篇
  2011年   375篇
  2010年   248篇
  2009年   183篇
  2008年   412篇
  2007年   369篇
  2006年   383篇
  2005年   392篇
  2004年   373篇
  2003年   393篇
  2002年   404篇
  2001年   307篇
  2000年   326篇
  1999年   326篇
  1998年   118篇
  1997年   82篇
  1996年   88篇
  1995年   92篇
  1994年   78篇
  1993年   99篇
  1992年   262篇
  1991年   231篇
  1990年   184篇
  1989年   173篇
  1988年   170篇
  1987年   174篇
  1986年   153篇
  1985年   146篇
  1984年   110篇
  1983年   79篇
  1982年   51篇
  1981年   51篇
  1979年   61篇
  1978年   53篇
  1977年   40篇
  1975年   49篇
  1974年   50篇
  1971年   41篇
  1969年   46篇
排序方式: 共有9044条查询结果,搜索用时 15 毫秒
991.
992.
This study investigates the ability of low doses of angiotensin-converting-enzyme inhibitors, in combination with angiotensin II receptor blockers, to exert antiproteinuric effects in normotensive and proteinuric outpatients with immunoglobulin A (IgA) nephropathy confirmed by biopsy. We performed a prospective, randomized, 6-month study of the effects of temocapril 1 mg (n=10), losartan 12.5 mg (n=10), and both (n=11) on mild-to-moderate proteinuria 0.76+/-0.35 g/day (range, 0.4 to 1.6 g/day) and renal function. The study subjects comprised 31 normotensive and proteinuric outpatients with IgA nephropathy accompanied by normal, or mild-to-moderately reduced but stable renal function (glomerular filtration rate>50 ml/min) without steroid or immunosuppressive therapy. We prospectively evaluated blood pressure, proteinuria, renal function and biochemical parameters before and after 6 months of therapy. The combination therapy significantly reduced proteinuria (63.2%) compared with either temocapril or losartan alone (41.3% and 36.6%, respectively, p=0.04 and 0.01, respectively). Blood pressure was most decreased in the group that received combination therapy. The reduced proteinuria did not correlate with reduced systolic or diastolic blood pressure or mean arterial pressure in any of the groups. The glomerular filtration rate fell during the first 3 months of combined therapy, but became reversible after a further 3 months of therapy. The combination significantly decreased angiotensin II (p <0.01), and this decrease was greater than that by either drug alone. In conclusion, the effectiveness of the combined therapy may have been at least partly due to the greater inhibition of the action of angiotensin II in patients with IgA nephropathy. This strategy apparently reduced mild-to-moderate proteinuria in patients with normotensive IgA nephropathy.  相似文献   
993.
994.
Urinary, fecal and biliary excretion, together with enterohepatic circulation, of radioactivity were studied after intravenous (50 mg eq/kg) and intramuscular (5 and 50 mg eq/kg) administration of [14C]-haloperidol decanoate in rats. The composition of urinary and biliary metabolites was also examined. The rate of excretion after intravenous administration lowered rapidly with the half-life of about 1.5 days and about 95% of dose was excreted in excreta within 10 days. Shortly after intramuscular administration, the rate of excretion lowered rapidly but then more gradually later (half-lives after administration of 5 and 50 mg eq/kg were 16.4 and 11.2 days, respectively). About 90% of dose was excreted within 42 days after intramuscular administration. About 1.6% of dose/day was excreted in the bile during 15-17 days after intramuscular administration, of which about 30% was reabsorbed within 24 h (enterohepatic circulation). The major urinary metabolite was p-fluorophenylaceturic acid and the biliary metabolite, glucuronide and sulfate of haloperidol. No unchanged decanoate was detected in the excreta.  相似文献   
995.
Vesical malacoplakia is a relatively rare disease and commonly diagnosed by characteristic cystoscopical findings and histological determination using biopsy specimen. We report here a case of a 53-year-old housewife, with atypical cystoscopical findings, which looked like carcinoma in situ, and in which randomized biopsy helped to make the final diagnosis. This case was successfully controlled by anti-bacterial agents.  相似文献   
996.
In order to establish the virological significance of HBeAg subtypes (HBeAg/1 and HBeAg/2) during hepatitis B virus infection, HBsAg, HBeAg and hepatitis B virus DNA in serum and HBcAg in liver were determined quantitatively in relation to the detection of HBeAg subtypes in agar gel diffusion. Thirty-eight chronic HBsAg carriers with HBeAg, including 16 non-specific reactive hepatitis, 8 chronic persistent hepatitis, 11 chronic active hepatitis and 3 liver cirrhosis, who were seen at Tohoku University Hospital from 1983 to 1985, were examined. Significantly larger amounts of HBsAg, HBeAg and hepatitis B virus DNA in serum and HBcAg in liver were found in patients positive for both HBeAg/1 and HBeAg/2 in serum than in those positive for only HBeAg/1 or negative for both subtypes. These results suggest that the presence of HBeAg/2 in serum may reflect the occurrence of active viral replication. When the detection pattern of HBeAg subtypes was examined during serial follow-up for at least 1 year, three groups of patients were classified with respect to the presence of HBeAg/2, i.e., Type I, consistently positive for HBeAg/2; Type II, consistently negative for HBeAg/2, and Type III, intermittently positive for HBeAg/2. More than 80% of Type I patients were histologically diagnosed having as nonspecific reactive hepatitis, while more than 80% of Type II and III patients had more progressive liver diseases such as chronic persistent hepatitis, chronic active hepatitis and liver cirrhosis. These results suggest that the serial examination of HBeAg subtypes in serum may be important for more detailed evaluations of type B hepatitis.  相似文献   
997.
998.
The interaction of muscle relaxants with airway muscarinic receptors of rabbit lung was investigated in vitro by the [3H]QNB binding technique. Pancuronium, vecuronium, alcuronium and succinyl choline chloride (SCC) inhibited the binding of [3H]QNB to rabbit lung muscarinic receptors in a dose-dependent manner. The values of IC50 (the concentration giving 50% inhibition) of pancuronium, vecuronium, alcuronium and SCC were 1.54 x 10(-5), 2.52 x 10(-5), 8.40 x 10(-5), and 4.00 x 10(-3) mol/l respectively. As the values of Kd increased with minimal change in the value of Bmax, while not influencing the number of receptors, these muscle relaxants had an inhibitory action on the affinity of muscarinic receptors to [3H]QNB in the order: pancuronium greater than or equal to vecuronium greater than alcuronium greater than SCC. Applying IC50 values to human conditions, clinical doses of these muscarinic relaxants are unlikely to exhibit any significant vagolytic action in lung tissue.  相似文献   
999.
1000.
The anti-tumor therapy followed by tumor lysis syndrome may cause the metabolic disorders including hyperkalemia, hyperphosphatemia and hyperuricemia. It should be known that it occurs frequently in lymphoproliferative diseases, especially in Burkitt's lymphoma. Two cases of T-ALL accompanied by this syndrome, from which the patients were recovered, at the induction therapy of the first complete remission are reported here. Case 1. A 28-year-old man received VP therapy under the diagnosis of T-ALL with massive hepatosplenomegaly and bilateral enlarged kidneys. During the therapy, metabolic disorders with both renal failure and ventricular tachycardia happened. They were resolved by certain series of treatments. The patient was brought to a complete remission with normal size of liver, spleen and kidneys. Case 2. A boy aged 15 having received the intrasubarachnoidal infusion of MTX and 1-Ad-VP therapy under the diagnosis of T-ALL accompanied by this syndrome which was improved by an appropriate treatment, and the patient was lead to the remission. The risk factors of this syndrome, such as 1-high drug sensitivity of the tumor; 2-renal dysfunction; 3-rapid cytokinetics of the tumor cell; 4-bigger size of the tumor, as well as the preventive treatment of this syndrome are reviewed.  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