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   1988篇
  免费   102篇
  国内免费   19篇
耳鼻咽喉   25篇
儿科学   94篇
妇产科学   129篇
基础医学   287篇
口腔科学   111篇
临床医学   158篇
内科学   279篇
皮肤病学   40篇
神经病学   206篇
特种医学   118篇
外科学   194篇
综合类   41篇
预防医学   106篇
眼科学   2篇
药学   178篇
中国医学   1篇
肿瘤学   140篇
  2023年   15篇
  2022年   21篇
  2021年   45篇
  2020年   24篇
  2019年   42篇
  2018年   36篇
  2017年   46篇
  2016年   37篇
  2015年   45篇
  2014年   53篇
  2013年   70篇
  2012年   115篇
  2011年   127篇
  2010年   69篇
  2009年   71篇
  2008年   96篇
  2007年   92篇
  2006年   93篇
  2005年   100篇
  2004年   84篇
  2003年   61篇
  2002年   73篇
  2001年   63篇
  2000年   62篇
  1999年   77篇
  1998年   54篇
  1997年   41篇
  1996年   19篇
  1995年   22篇
  1994年   19篇
  1993年   15篇
  1992年   24篇
  1991年   26篇
  1990年   21篇
  1989年   27篇
  1988年   17篇
  1987年   20篇
  1986年   21篇
  1985年   18篇
  1984年   9篇
  1983年   16篇
  1982年   12篇
  1981年   10篇
  1980年   8篇
  1978年   8篇
  1976年   8篇
  1972年   11篇
  1970年   8篇
  1969年   10篇
  1968年   9篇
排序方式: 共有2109条查询结果,搜索用时 15 毫秒
1.
A simple and rapid fluorimetric method for the determination of 9-fluoro-10-[N-(4′-methyl)piperazinyl]-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-d,e][1–4]benzothyazin-6-carboxylic acid hydrochloride (MF 934), in serum and in pharmaceutical formulations, has been developed based on its strong fluorescence, in 0.1 N H2SO4, at 526 nm (excitation wavelength at 340 nm). The procedure which involves the direct dilution of the sample requires only a few minutes and the sample volume is only 20–100 μl of serum, depending on the drug concentration. Tedious sample preparation procedures such as extraction, deproteinization, or centrifugation are not necessary. The minimum concentration that can be detected is 0.3 ng ml−1, the standard curve in 0.1 N H2SO4 was found to be linear from 0.005 to 1.5 μg ml−1 and from 0.01 to 0.07 g in plasma after dilution with 0.1 N H2SO4.  相似文献   
2.
3.
4.
Keratodermia is an incurable genetic and regional disease located in the palmar and plantar regions. The author reports his experience with five cases of palmoplantar keratodermia that were treated by grafting onto the soles and the palms skin taken from the calves and the thighs.  相似文献   
5.
The compound IBI-P-05006, 2-(6'-carboxyhexyl)-3-n-hexylcyclohexylamine, is an antiaggregating agent under development. IBI-P-05006 is an in vitro inhibitor of platelet aggregation. The biotransformation of this compound has been studied in the dog and rat. We present here a study on the metabolites of IBI-P-05006 found in dog and rat urine, and in dog plasma. Analyses were done by gas chromatography-mass spectrometry. In dog urine 15 metabolites were identified. Some of them were also found in dog plasma and in rat urine. The unmetabolized drug was found only in plasma. 10 different hydroxylated metabolites were characterized. The hydroxyl groups were introduced in the hexyl chain in positions omega-4, omega-3, omega-2, omega-1 and omega.  相似文献   
6.
OBJECTIVES: To evaluate the accuracy of sonographic identification of the site of umbilical cord insertion (CI) at 18-20 weeks of gestation, to compare the sensitivities for detection of a velamentous cord insertion (VCI) secondary to a CI into the anterior, posterior or fundal wall, and to compare the intrapartum complications secondary to VCI into the upper, middle or lower third of the uterus. METHODS: As part of the routine ultrasound scan at 18-20 weeks' gestation we evaluated abnormal CI (VCI and marginal CI) and the location of the CI in the uterus in 3446 pregnancies. In cases of abnormal CI, the location of the CI was further classified as being in the upper, middle or lower third of the uterus. After delivery, the placenta and the umbilical cord were examined and intrapartum complications were compared with the location of the CI. RESULTS: The values for antenatal detection of VCI were: sensitivity, 25 of 40 (62.5%); positive predictive value, 25 of 25 (100%); and negative predictive value, 3406 of 3421 (99.6%). The sensitivity for cases in which the CI was located on the anterior wall was 12 of 13 (92.3%); when it was located on the posterior wall, the sensitivity was 11 of 22 (50.0%); and when it was fundal the sensitivity was 2 of 5 (40.0%). Variable decelerations were frequently observed with a VCI. In lower VCI cases, non-reassuring fetal heart rate patterns and emergency Cesarean sections occurred with a higher frequency than in cases with upper or middle VCI (P < 0.01). After delivery, the length of the aberrant vessels in cases of VCI by pathologic examination was 3.9 +/- 3.3 cm in the upper third, 4.7 +/- 4.6 cm in the middle third, and 10.6 +/- 6.8 cm in the lower third; thus, the aberrant vessel length was significantly greater when the CI was in the lower third of the uterus (P = 0.024). CONCLUSION: We have demonstrated that VCI with a lower CI site and with longer aberrant vessels is associated with various intrapartum complications. This finding has the potential for improving perinatal outcome.  相似文献   
7.
Toxic pustuloderma associated with azithromycin   总被引:1,自引:0,他引:1  
  相似文献   
8.
BACKGROUND: Seborrhoeic dermatitis (SD) is a common dermatosis in human immunodeficiency virus (HIV)-positive patients, many of whom do not respond satisfactorily to conventional topical treatments such as corticosteroids and antifungals. OBJECTIVE: A pilot study to investigate the efficacy and tolerability of pimecrolimus cream 1% in HIV-positive patients with facial SD. METHODS: In a single-centre study, 21 HIV-infected patients with mild to severe SD were treated twice daily with pimecrolimus cream 1% for 14 days. Thereafter, treatment was discontinued and patients followed up for 5 weeks. Skin involvement at baseline and on days 7, 14, 21, 35 and 49 was assessed using a four-point clinical score and digital photography. MAIN OUTCOME MEASURES: Efficacy and safety of pimecrolimus cream 1% treatment and incidence of relapse in the follow-up phase. Results Marked improvement was seen in clinical parameters at day 7, with >or= 90% patients clear of symptoms at day 14. Relapse was observed at day 35 but signs were milder than at baseline. All patients responded to therapy, despite their immunological status. Pimecrolimus did not alter CD4(+) and CD8(+) T-cell counts or viral load during the treatment period. CONCLUSION: Pimecrolimus cream represents a new, effective therapeutic option for facial SD in HIV patients.  相似文献   
9.
10.
Summary The pharmacokinetics of the anticancer agent p-(3,3-dimethyl-1-triazeno) benzoic acid (pCOOH-DMT), a drug now in phase I clinical trial in Europe, was investigated in C57 Bl female mice with M5076 reticulum-cell sarcoma that were treated i.v. with 200 mg/kg pCOOH-DMT. The drug disappeared from plasma with a terminal half-life of about 2.5 h. Plasma clearance was approximately 6 ml/min per kg. Distribution studies showed some differences in drug levels in different tissues. The highest levels were found in the tumor, liver, kidney and lung; lower levels were found in the spleen and gut, and the lowest, in the brain. The N-desmethyl derivative of pCOOH-DMT was not detectable in plasma or tissues of mice treated with the drug. Therefore, the previous evidence of low N-demethylation of pCOOH-DMT was confirmed. pCOOH-DMT glucuronide was identified by mass spectrometry and quantified by high-performance liquid chromatography (HPLC) in plasma, tissues and urine samples. pCOOH-DMT glucuronide appears to be the major urinary metabolite of pCOOH-DMT in mice. Another metabolite identified by mass spectrometry and quantified by HPLC in some tissues and urine was pCOOH-DMT glycinate.Abbreviations DTIlC 5-(3,3-dimethyl-l-triazeno)imidazole-4-carboxamide - pCOOH-DMT p-(3,3-dimethyl-l-triazeno)benzoic acid - pCOOH-MMT p-(3-methyl-l-triazeno)benzoic acid - pCONH2-DMT p-(3,3-dimethyl-l-triazeno)carboxamide - BSTFA N,O-bis(trimethylsilyl)trifluoroacetamide - TMCS trimethylchlorosilane - TLC thin-layer chromatography - FAB fast atom bombardment - EI electron impact - M5 M5076 reticulum-cell sarcoma - t1/2 beta-half-life - C0 concentration time 0 - AUC area under the concentration vs time curve - Cl total clearance - V volume of distribution  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