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   129879篇
  免费   11472篇
  国内免费   6678篇
耳鼻咽喉   1244篇
儿科学   1967篇
妇产科学   2930篇
基础医学   13540篇
口腔科学   2678篇
临床医学   16050篇
内科学   20239篇
皮肤病学   1592篇
神经病学   6420篇
特种医学   4215篇
外国民族医学   40篇
外科学   13439篇
综合类   19606篇
现状与发展   20篇
一般理论   18篇
预防医学   9564篇
眼科学   3463篇
药学   13545篇
  115篇
中国医学   6852篇
肿瘤学   10492篇
  2024年   594篇
  2023年   1758篇
  2022年   4053篇
  2021年   5489篇
  2020年   4160篇
  2019年   3740篇
  2018年   3976篇
  2017年   3754篇
  2016年   3343篇
  2015年   5278篇
  2014年   6776篇
  2013年   6996篇
  2012年   10188篇
  2011年   10928篇
  2010年   7523篇
  2009年   6183篇
  2008年   7829篇
  2007年   7783篇
  2006年   7386篇
  2005年   6745篇
  2004年   4885篇
  2003年   4436篇
  2002年   3661篇
  2001年   3098篇
  2000年   2856篇
  1999年   2643篇
  1998年   1311篇
  1997年   1222篇
  1996年   987篇
  1995年   951篇
  1994年   886篇
  1993年   504篇
  1992年   889篇
  1991年   801篇
  1990年   668篇
  1989年   569篇
  1988年   525篇
  1987年   450篇
  1986年   357篇
  1985年   284篇
  1984年   184篇
  1983年   167篇
  1982年   95篇
  1981年   93篇
  1979年   140篇
  1978年   111篇
  1977年   83篇
  1974年   94篇
  1973年   72篇
  1972年   87篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Ten cases of pediatric fulminant hemophagocytic syndrome, encountered between 1986 and 1989, are described. They occurred in the summer, and the patients presented with fever, jaundice, hepatosplenomegaly, pancytopenia, coagulopathy, and abnormal liver function. Bone marrow studies revealed infiltration by atypical T-lymphoid cells, rare B immunoblasts, and mature histiocytes with hemophagocytosis. Initially, histiocytic medullary reticulosis was suspected in six cases. The clinical course was characterized by rapid deterioration, with a mean period of 16 days from onset of fever to death. The main causes of death were coagulopathy with multiple organ failure and opportunistic infection. In seven of eight cases studied by serologic assay and Southern blot hybridization, acute or active Epstein-Barr virus (EBV) infection was documented. It is suggested that an atypical or fulminant form of primary EBV infection distinct from classic infectious mononucleosis was prevalent in previously healthy children in Taiwan. Younger age involvement and seasonal clustering were characteristic of the disorder described.  相似文献   
82.
To determine the single- and multiple-dose ceftazidime kinetics, we administered ceftazidime, 2 gm intravenous bolus every 12 hours, to 14 infected Chinese patients with various degrees of renal function. Blood samples were drawn in serial after the first and 7th dose and serum ceftazidime concentrations were measured by high pressure liquid chromatography. Ceftazidime concentration-time data were fitted to a two-compartment model with a nonlinear regression program. Ceftazidime kinetics was unaltered by repeated dosing. Both total body clearance and elimination rate constant of ceftazidime decrease significantly in proportion to the creatinine clearance estimated by Bjornsson's method. Renal insufficiency did not modify the steady-state volume of distribution (Vdss) of ceftazidime which, however, appeared to be larger than those reported previously. This larger Vdss may be explained by acute infection process, confinement to bed, and increased extracellular fluid volume as a result of hypoalbuminemia. Our study indicates the estimated creatinine clearance as a useful guide to ceftazidime dosage adjustment and also emphasizes the clinical relevance of conducting kinetic studies of antibiotics in infected patients.  相似文献   
83.
Eighteen healthy adult volunteers completed an open-label, four-way crossover study designed to determine the bioequivalency of 160-mg cibenzoline [2-(2,2-diphenylcyclopropyl)-4,5-dihydro-1H-imidazole] capsules and tablets, their relative bioavailability compared with an oral solution of the drug, as well as the absolute bioavailability of these dosage forms compared with an intravenous infusion of the drug. Blood samples obtained at specified times after drug administration were assayed for cibenzoline by HPLC, and pharmacokinetic parameters were estimated from the resulting plasma concentration-time profiles. Comparisons were made between the tablet and capsule to assess bioequivalency, between the solid dosage forms and a solution to assess relative bioavailability, and between the oral forms and an intravenous infusion to assess absolute bioavailability. The pharmacokinetic parameters for each oral dosage form were similar and ratios of mean parameters indicated that the solid dosage forms were bioequivalent and completely bioavailable relative to an oral solution. The ratios of the area under the plasma concentration-time profiles (AUC) for the capsule, tablet, and oral solution to that of the intravenous infusion were 0.85, 0.83, and 0.86, respectively, indicating that orally administered cibenzoline has an absolute bioavailability of approximately 85%.  相似文献   
84.
Metastatic septic endophthalmitis in pyogenic liver abscess   总被引:4,自引:0,他引:4  
In a consecutive series of 180 patients with pyogenic liver abscess, three patients (two men and one woman, between 46 and 75 years of age) had metastatic Klebsiella endophthalmitis. The incidence of metastatic endophthalmitis was 1.7% in patients with pyogenic liver abscess, 5.2% in patients with Klebsiella liver abscess, and 7.8% in patients with Klebsiella liver abscess having Klebsiella bacteremia. Despite aggressive therapeutic measures, the men permanently lost their vision and the woman eventually required an evisceration of her right eye. Delayed recognition and/or treatment as well as the nature of bacteria probably contributed to the tragic outcome. The findings suggest that a high index of suspicion is critical and a combined effort of the internist and ophthalmologist is mandatory.  相似文献   
85.
BACKGROUND AND PURPOSE: Birth certificates are a major source of population-based data often used in maternal and child health research, but their value depends upon the level of accuracy of the data. The purpose of this study was to assess the validity of the birth registry data in Taiwan. METHODS: Obstetric records of a total of 2779 infants born at a municipal hospital in Taipei between 1995 and 1997 were abstracted and linked to the Taiwan Birth Registry (TBR). Concordance was presented by agreement percentages for various birth characteristics including gender, birth order, birth weight, and gestational age. Concordance was further assessed using Cohen's k and sensitivity/specificity for both birth weight and gestational age, with both variables categorized according to their customary definitions. RESULTS: Missing data for specific items in the TBR ranged from 0% (gender) to 1.6% (birth order). The birth registry accurately reported all 4 selected items, with the highest and lowest concordance percentage noted for gender (99.0%) and gestational age (88.3%), respectively. The level of agreement indicated by the Cohen's k statistic ranged from 0.92 to 0.96 for birth weight and gestational age when both variables were treated as categorical variables. CONCLUSIONS: The TBR showed a low rate of missing information and high levels of validity for the elements frequently used in maternal and child health research in Taiwan.  相似文献   
86.
This study analyzed the feasibility of fitting keratoconus-affected corneas with nonkeratoconus rigid gas-permeable (RGP) contact lenses. We retrospectively studied patients with a diagnosis of keratoconus in the past 10 years who were fitted successfully with nonkeratoconus RGP lenses by the same physician. Results confirmed nonkeratoconus RGP lenses as the first-line correction tool. Additionally, we found a simple equation to speed the choice of the base curves of the lenses. The authors have stated that they do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.  相似文献   
87.
88.
Within the Huntington's disease (HD) candidate region of 4p16.3, the D4S127 locus displays strong linkage disequilibrium with the defect and anchors a conserved haplotype found on many HD chromosomes. To isolate genes from this region we have applied the exon amplification technique to overlapping cosmids spanning D4S127. Here, we report the discovery of a new gene encoding a novel member of a family of protein kinases that specifically phosphorylate the activated forms of G protein-coupled receptors. Such kinases are thought to participate in desensitization of specific receptors, thereby blocking further signal transduction. This gene must now be carefully scrutinized to determine whether it might be involved in HD.  相似文献   
89.
90.
L M Chuang  H P Wu  T S Jou  T Y Tai  B J Lin 《Pancreas》1992,7(4):472-476
Islet amyloid polypeptide (IAPP) has been recently identified as the principal constituent of amyloid deposits in pancreatic islets of patients with type 2 (non-insulin-dependent) diabetes mellitus and causes insulin resistance in some target cells. In addition, glucose-induced insulin secretion is inhibited by IAPP. We studied the effect of IAPP on proinsulin biosynthesis in rat insulinoma (RINr) cells. Glucose at concentrations of 0, 15, 30, 60, 100, and 300 mg/dl stimulated proinsulin biosynthesis in a dose-responsive and and actino-mycin D-inhibitable manner after 6 h of incubation. At a glucose concentration of 300 mg/dl, IAPP decreased the mean responses of proinsulin biosynthesis to 61.2 and 29% at concentrations of 0.1 and 1 microM, respectively, compared with the IAPP-free control. In conclusion, IAPP inhibits glucose-induced proinsulin biosynthesis in RINr cells. IAPP might play an important role in the pathogenesis of type 2 diabetes mellitus.  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