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   279篇
  免费   20篇
  国内免费   6篇
儿科学   10篇
妇产科学   6篇
基础医学   25篇
口腔科学   5篇
临床医学   23篇
内科学   81篇
皮肤病学   1篇
神经病学   45篇
特种医学   35篇
外科学   8篇
综合类   5篇
预防医学   15篇
眼科学   22篇
药学   18篇
肿瘤学   6篇
  2023年   2篇
  2022年   2篇
  2019年   2篇
  2018年   5篇
  2017年   5篇
  2015年   6篇
  2014年   4篇
  2013年   11篇
  2012年   7篇
  2011年   13篇
  2010年   7篇
  2009年   7篇
  2008年   8篇
  2007年   7篇
  2006年   4篇
  2005年   15篇
  2004年   14篇
  2003年   11篇
  2002年   5篇
  2001年   15篇
  2000年   9篇
  1999年   10篇
  1998年   15篇
  1997年   12篇
  1996年   15篇
  1995年   8篇
  1994年   7篇
  1993年   8篇
  1992年   6篇
  1990年   6篇
  1989年   6篇
  1988年   6篇
  1987年   5篇
  1986年   4篇
  1985年   3篇
  1984年   4篇
  1983年   7篇
  1982年   2篇
  1981年   2篇
  1979年   1篇
  1978年   1篇
  1977年   3篇
  1976年   1篇
  1975年   2篇
  1974年   1篇
  1972年   3篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1965年   2篇
排序方式: 共有305条查询结果,搜索用时 15 毫秒
1.
Neuroendocrine effects in printing workers exposed to toluene.   总被引:3,自引:0,他引:3  
The effect of exposure to toluene on plasma concentrations of testosterone, prolactin, luteinising (LH) and follicle stimulating (FSH) hormones was investigated in 47 rotogravure printers (time weighted average air toluene below 80 ppm; blood toluene concentration post-shift 0.19-7.99 mumol/l) and compared with a reference group. Increasing exposure concentrations of toluene (concentrations less than 5 to greater than 45 ppm) were significantly associated with decreasing plasma concentrations of LH (tau = -0.21, p = 0.003) and testosterone (tau = -0.25, p = 0.02). No correlation was found between cumulative exposure (ppm x years) and plasma hormone concentrations. The associations with exposure were present even when nine printers with heavy alcohol consumption were excluded. The study indicates an effect of low toluene exposure on the hypothalamus-pituitary axis, with a secondary decrease in testosterone secretion.  相似文献   
2.
3.
Hay  CR; Laurian  Y; Verroust  F; Preston  FE; Kernoff  PB 《Blood》1990,76(5):882-886
Home therapy with porcine factor VIIIC was safe and effective when administered to five hemophilic patients over periods of 8 1/2, 6, 4, 3 1/2, and 2 years. No significant transfusion reactions occurred. Before treatment with porcine factor VIIIC, all five had high-level, high- responding anti-human VIIIC inhibitors initially lacking anti-porcine factor VIIIC activity. Although specific anti-porcine VIIIC inhibitors arose in all patients, these were generally transient, and only one patient became refractory to treatment. We believe that porcine factor VIIIC is the treatment of choice in patients whose inhibitors do not cross-react. All five patients lost their original anti-human VIIIC inhibitors after starting treatment with porcine VIIIC, permitting the reintroduction of human VIIIC in three of them. There has been no recurrence of anti-human VIIIC inhibitor activity during 2 to 3 years of regular treatment with human VIIIC in these patients. This suggests that tolerance to human VIIIC has arisen as a result of treatment with porcine VIIIC. Porcine VIIIC may have a role in the desensitization of some factor VIIIC inhibitor patients.  相似文献   
4.
OBJECTIVE: In childhood onset GH deficiency (GHD) a reduction in left ventricular mass (LV-mass) and impairment of systolic function as well an impairment in glomerular filtration rate (GFR) has been shown. The aim of the present study was to assess if a low GH dose resulted in an improvement in morphological and functional parameters of these organs. DESIGN AND PATIENTS: Eleven patients with childhood onset GHD were investigated before and after 10 months of GH treatment at a dose of 1.5 IU/day (range 1-2), corresponding to 0.02 IU/kg/day or 7 microg/ kg/day. The GH dose resulted in a serum IGF-I level in the normal range in all but one patient. MEASUREMENTS: Doppler echocardiography of the heart and ultrasound examination of the kidneys was performed. Glomerular filtration rate (GFR) was estimated with iohexol clearance and urinary proteinuria was measured with 24-h urinary samples collected for analyses of albumin, alpha-1-microglobulin, IgG and albumin/creatinine clearance ratio. Body composition was measured by bioelectric impedance analysis. RESULTS: L V-mass index increased significantly after GH treatment (P = 0.04), and there was a clear trend for a positive correlation between the increase in serum IGF-I and the increase in LV-mass index, although it did not reach significance (r= 0.57, P = 0.07). GH treatment did not increase cardiac fractional shortening. Kidney length increased significantly (P = 0.02) with an average increase of 1 cm (range - 0.5-1.5 cm). No significant changes in median GFR or serum creatinine were recorded. Three patients with subnormal GFR before GH treatment normalized after 10 months of treatment. Urine analysis showed no abnormalities before or after GH treatment. A significant decrease in percentage fat mass was recorded (P = 0.03). CONCLUSION: A low individualized GH dose to adults with childhood onset GHD resulted in an increase in LV-mass index and kidney length. Re-establishing GH treatment with a low dose in this patient group can lead to a further somatic maturation of these organs, probably not accomplished previously.  相似文献   
5.
Plasma homocysteine concentrations in a group of 80-year-old persons were related to symptoms and signs. Plasma homocysteine concentrations higher than 15 mumol/l were associated with lower total life satisfaction (P<0.01), mood (P<0.05), zest for life (P<0.05), lower scores for reasoning (P<0.05), spatial ability (P<0.05), memory recognition (P<0.05), and subjective health (P<0.01). In an instrument comprising of 30 symptoms, plasma homocysteine concentrations higher than 15 mumol/l were associated with impaired concentration (P<0.05), restlessness (P<0.05), feeling cold (P<0.05), loss of weight (P<0.05), and feeling depressed (P<0.01). The above data indicate that plasma homocysteine values over 15 mumol/l could be relevant markers for clinical intervention.  相似文献   
6.
Cash  FE; Monplaisir  N; Goossens  M; Liebhaber  SA 《Blood》1989,74(2):833-835
Two alpha-globin structural mutants were mapped to their encoding loci by in vitro translation of hybrid-selected alpha 1- and alpha 2-globin mRNA. The more highly expressed mutant, alpha Spanish Town (alpha 27Val), is encoded at the alpha 2 locus and the less expressed mutant, alpha Fort de France (alpha 45Arg), is encoded at the alpha 1 locus. These results further define the distribution of alpha-globin structural mutations within the alpha-globin gene cluster and substantiate the dominant role of the alpha 2-globin locus in alpha- globin expression.  相似文献   
7.
8.
Introduction and ObjectivesThe emergence of SARS-CoV-2, which causes the coronavirus disease (COVID-19) has caused a great impact on healthcare systems worldwide, including hepatitis B and C viruses screening and elimination programs. The high number of COVID-19 hospitalizations represent a great opportunity to screen patients for hepatitis B virus (HBV) and hepatitis C virus (HCV), which was the aim of this study.Material and MethodsCross-sectional, retrospective study performed between April 2020 and 20201 at a referral center in Mexico dedicated to the care of adults with severe/critical COVID-19. We retrieved clinical, demographic, and laboratory results from each patient´s medical records, including antibodies against HCV (anti-HCV), HBV surface antigen (HBsAg), antibodies against the HBV core antigen (anti-HBcAg), and antibodies against HBsAg (anti-HBsAg).ResultsOut of 3620 patients that were admitted to the hospital, 24 (0.66%), 4 (0.11%), and 72 (1.99%) tested positive for anti-HCV, HBsAg, and anti-HBcAg, respectively. Of all seronegative patients, 954 (27%) had undetectable anti-HBsAg and 401 (12%) had anti-HBsAg at protective levels. Blood transfusion was the most relevant risk factor. Only 9.7% of the anti-HBc positive, 25% of the HBsAg positive, and 52% of the anti-HCV positive were aware of their serological status.ConclusionsIn this study we found a prevalence of anti-HCV of 0.66%, HBsAg in 0.11%, and isolated anti-HBcAg in 1.99%. We also found that HBV vaccination coverage has been suboptimal and needs to be reinforced. This study gave us a trustworthy insight of the actual seroprevalence in Mexico, which can help provide feedback to the Hepatitis National Elimination Plan.  相似文献   
9.
Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, and until recently prophylactic cranial radiotherapy (CRT) was important for achieving long-term survival. Hypothalamic-pituitary hormone insufficiency is a well-recognized consequence of CRT for childhood cancer. Another problem is increased cardiovascular risk, which has been shown in long-term survivors of other childhood cancers. In the only previously reported study on cardiovascular risk after childhood ALL, obesity and dyslipidemia were recorded in a small subgroup treated with CRT, compared with patients treated with chemotherapy. The mechanisms behind the increase in cardiovascular risk in survivors of childhood cancer are not clarified.The aim of the present study was to elucidate mechanisms of increased cardiovascular risk in former childhood ALL patients. A group of 44 ALL survivors (23 males, median age 25 yr, range 19-32 yr at the time of study) treated with CRT (median 24 Gy, 18-30 Gy) at a median age of 5 yr (1-18 yr) and chemotherapy were investigated for prevalence of GH deficiency and cardiovascular risk factors. Comparison was made with controls randomly selected from the general population and individually matched for sex, age, smoking habits, and residence. All patients and controls underwent a GHRH-arginine test, and patients with a peak GH 3.9 microg/liter or greater were further investigated with an additional insulin tolerance test.Significantly higher plasma levels of insulin (P = 0.002), blood glucose (P = 0.01), and serum levels of low-density lipoprotein cholesterol, apolipoprotein (Apo) B, triglycerides, fibrinogen, and leptin (all P 相似文献   
10.
Erfurth A  Arolt V 《Der Nervenarzt》2003,74(1):55-70; quiz 70-1
On the basis of epidemiology, neurobiology and clinical observation, the classification of bipolar disorders has shown considerable development and expansion in recent years. In particular, the recognition of mixed states, the introduction of bipolar II disorders, increasing awareness of the diagnosis of hypomania, as well as the interest in cyclothymic disorders and temperament have led to a shift in diagnostic attitudes in the USA, as well as in European countries. In this article, the possible clinical and scientific benefits of such tendencies are discussed, as are the risks of broadening bipolar disorders beyond DSM-IV.Also demonstrated is how several "modern" concepts of bipolarity have deep roots in the history of German psychiatry; a mixity scale based on Kraepelin's classification of affective mixed states is presented.  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