首页 | 官方网站   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   1233篇
  免费   74篇
  国内免费   3篇
医药卫生   1310篇
  2023年   15篇
  2022年   12篇
  2021年   74篇
  2020年   27篇
  2019年   29篇
  2018年   55篇
  2017年   45篇
  2016年   47篇
  2015年   35篇
  2014年   54篇
  2013年   69篇
  2012年   99篇
  2011年   111篇
  2010年   41篇
  2009年   50篇
  2008年   62篇
  2007年   74篇
  2006年   54篇
  2005年   50篇
  2004年   51篇
  2003年   35篇
  2002年   33篇
  2001年   15篇
  2000年   18篇
  1999年   25篇
  1998年   10篇
  1997年   5篇
  1996年   5篇
  1995年   9篇
  1994年   2篇
  1993年   2篇
  1992年   10篇
  1991年   5篇
  1990年   13篇
  1989年   4篇
  1988年   5篇
  1987年   9篇
  1986年   12篇
  1985年   8篇
  1984年   2篇
  1983年   2篇
  1980年   2篇
  1978年   5篇
  1976年   4篇
  1975年   2篇
  1974年   3篇
  1973年   4篇
  1970年   2篇
  1968年   2篇
  1963年   1篇
排序方式: 共有1310条查询结果,搜索用时 15 毫秒
51.
52.
A reliable and sensitive ultra-performance liquid chromatography-tandem mass spectrometry-based method has been developed for the estimation of 4-hydroxyisoleucine (4-HI), a potent insulinotropic and hypolipidemic agent. The extraction of 4-HI from plasma was accomplished by the protein precipitation technique using l-isoleucine as an internal standard. The separation of analytes was achieved with a mobile phase consisting of acetonitrile and 0.1% formic acid in an isocratic flow system on a BEH Shield RP-18 column (150 mm × 2.1 mm, 1.7 μm). 4-HI and l-isoleucine were detected using an electrospray ionization (ESI) ion source, using multiple reaction monitoring (MRM) in positive ion mode. The precursor to product ion transitions of 4-HI and l-isoleucine were found at m/z values of 148.19 > 74.02 and 132.17 > 69.04, respectively. As per the guidelines for bioanalytical methods, all validation parameter results were within the acceptable range. The method exhibited a robust and reproducible linearity range of 1–5000 ng mL−1 with a coefficient of regression of 0.9999. The method was successfully applied for the estimation of pharmacokinetic parameters after oral administration of 4-HI (10 mg kg−1) in Wistar rats, by using Thoth Pro (version: 4.3) software. Herein, the two-compartment model was statistically fitted based on AIC and SBC values for evaluation of the pharmacokinetic parameters of 4-HI. Pharmacodynamic studies were also performed by measuring the levels of triglyceride and total cholesterol, and showed that the pharmacokinetic and pharmacodynamic data of 4-HI correlated with each other.

A reliable and sensitive UPLC-MS/MS based method has been developed for the estimation of 4-hydroxyisoleucine, a potent insulinotropic and hypolipidemic agent.  相似文献   
53.
54.
PURPOSE: Ashwagandha is regarded as a wonder shrub of India and is commonly used in Ayurvedic medicine and health tonics that claim its variety of health-promoting effects. Surprisingly, these claims are not well supported by adequate studies, and the molecular mechanisms of its action remain largely unexplored to date. We undertook a study to identify and characterize the antitumor activity of the leaf extract of ashwagandha. EXPERIMENTAL DESIGN: Selective tumor-inhibitory activity of the leaf extract (i-Extract) was identified by in vivo tumor formation assays in nude mice and by in vitro growth assays of normal and human transformed cells. To investigate the cellular targets of i-Extract, we adopted a gene silencing approach using a selected small hairpin RNA library and found that p53 is required for the killing activity of i-Extract. RESULTS: By molecular analysis of p53 function in normal and a variety of tumor cells, we found that it is selectively activated in tumor cells, causing either their growth arrest or apoptosis. By fractionation, purification, and structural analysis of the i-Extract constituents, we have identified its p53-activating tumor-inhibiting factor as with a none. CONCLUSION: We provide the first molecular evidence that the leaf extract of ashwagandha selectively kills tumor cells and, thus, is a natural source for safe anticancer medicine.  相似文献   
55.
One hundred and forty four cases of febrile seizures, 95 simple (typical) and 49 complex (atypical); were studied and compared for clinical and epidemiological data and family history of febrile and afebrile seizures. Major results were: maximum age of onset below three years (75%) in both simple and complex groups, male preponderance, respiratory infection as the commonest etiology (69.4%) and maximum seizure onset within 24 hours of fever (73%). The familial prevalence of all seizures was 29.1%, 23.2% in the simple and 40.8% in the complex group (p < 0.01). The familial prevalence of febrile seizures was 20%; similar in both groups. The familial prevalence of afebrile seizures was 13.9%; 6.3% in simple and 28.6% in complex group (p < 0.01). The commonest relative was a sibling (13.2%). The prevalence in parents was 4%. Families with two additional members with history of seizures revealed complex seizure patterns in two-thirds of index cases. There was no correlation between family history of seizures and age at onset or sex. No clear inheritance pattern emerged and polygenic inheritance is likely. One third of eighteen families had siblings with identical segregation of parental HLA-A and B haplotypes. Five families showed the presence of HLA All. This small though adequate sample size did not reveal an HLA marker for febrile seizures.  相似文献   
56.
Five thousand children under 6 years of age from 69 villages in Haryana were followed up for 2 years to assess the extent and severity of acute diarrheal disease. Almost 70–75 per cent of children suffered from diarrhea every year. The annual attack rate was 1·92/child during the first year and 2·16/child in the second year. Thirty four per cent suffered from 3 or more episodes. Maximum attack rate of 2·69/child/year was seen in children 1–2 years of age. No severe dehydration was seen and one or more signs of dehydration were reported in 3013 (12·2%) cases. Diarrhea accounted for 23·1 per cent (27) of total deaths (117) during the study period. The case fatality rate in 7424 episodes of diarrhea was 3·63/1000 episodes. The findings of this prospective study have operational and logistic implications in national diarrheal disease control programme and may strengthen the monitoring of the desease.  相似文献   
57.
Diabetes disease management in a community-based setting   总被引:1,自引:0,他引:1  
PURPOSE: The medical cost of diabetes in the United States in 1997 was at least $98 billion. This study illustrates the behavioral change and medical-care utilization impact that occurs in a community-based setting of a diabetes disease-management program that is applied to program participants in a health insurance plan's health maintenance organization and preferred provider organization. DESIGN: A historical control comparison of diabetes-management participants. METHODOLOGY: One hundred twenty-seven identified diabetes patients are followed from baseline through 1 year. Differences in behavior are compared at program intake and at a 6-month reassessment. Differences in medical-service utilization are compared in the baseline year and the year subsequent to program enrollment. Poisson multivariate-regression models are estimated for counts of inpatient, emergency department, physician evaluation and management, and facility visits, while also controlling for potential confounders. PRINCIPAL FINDINGS: Behaviors improved between program intake and the 6-month reassessment. From patient reports, the number of participants having a hemoglobin A1c test increased by 44.9 percent (p < .001), and there was a 53.2-percent decrease in symptoms of hyperglycemia (p = .002). From medical claims after program enrollment, a drop occurred during the program year in every dimension of medical-service utilization. Regression results show that in-patient admissions decreased by 391 (p < .001) per 1,000 for each group, while controlling for age, length of membership, and the number of comorbid claims for congestive heart failure. In the analysis of costs that were pre- and post-enrollment, which included disease-management program costs, a 4.34:1 return on investment was calculated. CONCLUSION: The diabetes program provides patients with comprehensive information and counseling relative to practicing self-management of diabetes through a number of integrated program components. This study strongly suggests that the implementation of such a program is associated with positive behavioral change and, thus, with substantial reduction in medical-service utilization. In addition, the intervention resulted in a net decrease in direct medical costs.  相似文献   
58.
59.
It is recognized that training methods differ among the various medical colleges; however, trained specialists should be competent to discharge their duties independently in any part of the country. Therefore, to maintain uniform standards of education, there is a need to harmonize postgraduate training in anatomy. It is proposed that a structured training programme should be drawn up and monitored regularly at specified intervals, spelling out some clearly defined targets that need to be achieved. The ultimate goal of the postgraduate training programme should be to produce anatomists with sufficient knowledge and practical skills to undertake undergraduate teaching and evaluation in all branches of anatomy, as well as to pursue research independently.  相似文献   
60.
In patients with multiple myeloma, a good complete response rate and disease-free survival may be achieved with sequential chemotherapy using VAD and VMCP, which is an alternative effective and less expensive treatment regimen. This regimen thus assumes particular significance in developing nations like India, where the majority of patients with myeloma cannot afford the cost of high-dose chemotherapy with stem cell rescue.  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-23

京公网安备 11010802026262号