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   267篇
  免费   19篇
  国内免费   4篇
儿科学   21篇
妇产科学   4篇
基础医学   29篇
口腔科学   6篇
临床医学   27篇
内科学   66篇
皮肤病学   2篇
神经病学   13篇
特种医学   10篇
外科学   28篇
综合类   42篇
预防医学   17篇
眼科学   2篇
药学   3篇
中国医学   2篇
肿瘤学   18篇
  2021年   3篇
  2020年   3篇
  2019年   4篇
  2018年   7篇
  2017年   4篇
  2016年   3篇
  2015年   6篇
  2014年   5篇
  2013年   5篇
  2012年   8篇
  2011年   5篇
  2010年   9篇
  2009年   9篇
  2008年   5篇
  2007年   10篇
  2006年   9篇
  2005年   4篇
  2004年   5篇
  2003年   8篇
  2002年   3篇
  2001年   11篇
  2000年   4篇
  1999年   10篇
  1998年   12篇
  1997年   11篇
  1996年   17篇
  1995年   10篇
  1994年   5篇
  1993年   4篇
  1992年   10篇
  1991年   8篇
  1990年   9篇
  1989年   9篇
  1988年   7篇
  1987年   6篇
  1986年   5篇
  1985年   5篇
  1984年   6篇
  1982年   3篇
  1981年   5篇
  1980年   2篇
  1979年   1篇
  1977年   1篇
  1976年   2篇
  1975年   3篇
  1973年   2篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
  1967年   1篇
排序方式: 共有290条查询结果,搜索用时 15 毫秒
1.
(1) Liver cirrhosis was induced in male rats by treatment with carbon tetrachloride and phenobarbitone for 130-142 days. Detailed histological examination showed all livers from rats treated with carbon tetrachloride had annular fibrosis, necrosis, loss of normal hepatic architecture and other features that were consistent with an established micronodular cirrhosis. (2) Plasma biochemical analysis showed a significant reduction in total protein concentration (13%), which was due entirely to a reduction in plasma albumin (29%). There were also large increases in the plasma activities of alkaline phosphatase (110%) and aspartate aminotransferase (159%), when compared to phenobarbitone-treated controls. Plasma cholesterol was also increased (67%), but other plasma analytes were not significantly altered. (3) The soleus (Type I), plantaris (Type II) and gastrocnemius (Types I and II) muscles were dissected and examined for possible differential effects. There were minor reductions in all three muscle weights, but these changes did not reach statistical significance. The protein, RNA and DNA concentrations, total muscle content and content relative to body weight in cirrhotic rats were also not significantly altered in any of the muscles. Cirrhosis did not cause any perturbations in derived parameters, i.e. amount of synthetic apparatus per cell, RNA/DNA ratio, apparent cell size, protein/DNA ratio and the capacity for protein synthesis or RNA/protein ratio. (4) The gastrocnemius was fractionated into soluble, stromal and myofibrillar proteins. The concentrations and contents of all three proteins were unaltered in cirrhotic animals, compared to controls. (5) It is concluded that in this experimental model of cirrhosis there were no effects on those skeletal muscle variables which are strikingly altered by chronic alcohol feeding.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
2.
The acute effects of serum from patients with fulminant hepatic failure (FHF) on isolated hepatocytes from normal and regenerating rat livers were investigated. DNA and protein synthesis monitored by following the incorporation of [6-3H]-thymidine and [U-14C]-1-leucine into acid-precipitable material was accelerated in hepatocytes from regenerating livers. A specific inhibitory effect of FHF serum on DNA synthesis in hepatocytes from regenerating livers was found. DNA and protein synthesis was inhibited in normal rat hepatocytes by normal serum, the inhibition being less with FHF serum. Cell integrity assessed by leakage of lactate dehydrogenase was not affected by normal or FHF serum. These findings may explain the reduced rate of hepatic regrowth in patients with FHF. Identification of the substances involved will assist in the design of artificial liver support systems and may improve prognosis in this condition.  相似文献   
3.
Germline mutations of the CDKN2 gene in UK melanoma families   总被引:4,自引:1,他引:4  
Germline mutations in CDKN2 on chromosome 9p21, which codes for the cyclin D kinase inhibitor p16, and more rarely, mutations in the gene coding for CDK4, the protein to which p16 binds, underlie susceptibility in some melanoma families. We have sequenced all exons of CDKN2 and analysed the CDK4 gene for mutations in 27 UK families showing evidence of predisposition to melanoma. Five different germline mutations in CDKN2 were found in six families. Three of the mutations (Met53Ile, Arg24Pro and 23ins24) have been reported previously. We have identified two novel CDKN2 mutations (88delG and Ala118Thr) which are likely to be associated with the development of melanoma, because of their co-segregation with the disease and their likely functional effect on the CDKN2 protein. In binding assays the protein expressed from the previously described mutation, Met53Ile, did not bind to CDK4/CDK6, confirming its role as a causal mutation in the development of melanoma. Ala118Thr appeared to be functional in this assay. Arg24Pro appeared to bind to CDK6, but not to CDK4. No mutations were detected in exon 2 of CDK4, suggesting that causal mutations in this gene are uncommon. The penetrance of these mutant CDKN2 genes is not yet established, nor is the risk of non-melanoma cancer to gene carriers.   相似文献   
4.
Renal transplantation has become a treatment of choice for patients with end stage renal disease. A successful transplant is the result of a combination of several factors acting synergistically, such as the degree of HLA compatibility between donor and the recipient, pretransplant blood transfusions, the recipient''s state of immunoreactivity and sensitization, immunosuppressive therapy given in post operative period etc. Donor selection appears to be the most critical factor for the long term success of the organ graft. In this brief review, some of the important parameters of donor selection in renal transplantation are highlighted.KEY WORDS: Histocompatibility (HLA) matching, Cross match, Sensitization  相似文献   
5.
6.
Proteus syndrome     
Abstract: This female Asian (Malay) baby had clinical features of Proteus syndrome. She had a large right facial lipolymphangioma with hyperpigmentation of the overlying skin. There was a smaller lymphangioma over the left side of her neck with excess nuchal folds, macrodactyly and bilateral talipes equinovarus. Despite the extensive hemifacial swelling, there was no evidence of upper respiratory tract obstruction. Generalized seizures developed on the sixth day of life which were controlled with phenobarbital. The lymphangiomas were excised without recurrence.  相似文献   
7.
Two-hundred and eighty bacterial isolates from wound and soft tissue infections were studied for species identification and antibiotic resistance pattern. Amongst them 122 isolates were from community acquired infection and 158 were from nosocomial infections. The common community acquired pathogens were Staphylococcus aureus (67.8%) and Streptococcus pyogenes (10.7%), whereas Staphylococcus aureus (60.1%) and E. Coli (8.9%) were common in nosocomial infection. Only two anaerobes (Cl perfringens) were isolated. Penicillin resistance was found to be 87% and 92% for Staphylococccus aureus in community acquired and noscomial infections respectively. 85% of Proteus isolates were resistant to ampicillin. There was relatively lower level of resistance by all isolates to cefotaxime. Gentamicin showed higher rate of resistance than netilmicin and amikacin. Resistance of E. coli isolates to fluoroquinolones being 79% for norfloxacin, 81% for ciprofloxacin and 60% for ofloxacin. The study showed a higher resistance of methicillin resistant Staphylococcus aureus (MRSA) to other antibiotics. Amikacin and ofloxacin were the best recommended drugs for empirical therapy for all organisms, the susceptibility rate being 80.7% and 80.4%.KEY WORDS: Antibiotic resistance, Soft tissue infections, Wound infections  相似文献   
8.
BACKGROUND: Streptococcus pneumoniae is a leading cause of invasive bacterial disease and pneumonia among children. Antimicrobial resistance among pneumococci has increased in recent years and complicates treatment. The introduction of heptavalent pneumococcal conjugate vaccine (PCV7) could reduce acquisition of antimicrobial-resistant pneumococci. METHODS: We obtained 1350 nasopharyngeal swabs for culture from 1275 children aged 3-59 months presenting at 3 clinics in Anchorage, Alaska, during the winters of 2000, 2001, and 2002, as PCV7 was being introduced into the routine immunization schedule. We recorded the frequency of use of antibiotics as well as the dates of doses of PCV7 for enrolled children. We used multivariate logistic regression modeling to identify independent risk factors for overall carriage of pneumococci and carriage of PCV7-type pneumococci, cotrimoxazole-nonsusceptible (COT-NS) pneumococci, or penicillin-nonsusceptible (PCN-NS) pneumococci. RESULTS: The proportion of children who were up-to-date for age, with respect to PCV7 vaccination, increased from 0% in 2000 to 55% in 2002. Carriage of PCV7-type pneumococci decreased by 43% (P<.0001). Risk of carriage of PCV7-type pneumococci was lower in 2002 than in 2000, independent of vaccination status, suggesting an indirect effect of vaccination. Carriage of COT-NS, but not PCN-NS, pneumococci also decreased (38%; P=.02), not only among vaccinated children but also among unvaccinated children without recent use of antibiotics. CONCLUSIONS: Introduction of PCV7 into the routine infant immunization schedule in a community with a high prevalence of antimicrobial-resistant pneumococci appears to reduce transmission of PCV7 vaccine serotypes and COT-NS pneumococci but has no impact on overall carriage of pneumococci or carriage of PCN-NS pneumococci.  相似文献   
9.
Increased production of reactive oxygen species (ROS) is implicated in the development of left ventricular hypertrophy (LVH). Phagocyte-type NADPH oxidases are major cardiovascular sources of ROS, and recent data indicate a pivotal role of a gp91phox-containing NADPH oxidase in angiotensin II (Ang II)-induced LVH. We investigated the role of this oxidase in pressure-overload LVH. gp91phox-/- mice and matched controls underwent chronic Ang II infusion or aortic constriction. Ang II-induced increases in NADPH oxidase activity, atrial natriuretic factor (ANF) expression, and cardiac mass were inhibited in gp91phox-/- mice, whereas aortic constriction-induced increases in cardiac mass and ANF expression were not inhibited. However, aortic constriction increased cardiac NADPH oxidase activity in both gp91phox-/- and wild-type mice. Myocardial expression of an alternative gp91phox isoform, Nox4, was upregulated after aortic constriction in gp91phox-/- mice. The antioxidant, N-acetyl-cysteine, inhibited pressure-overload-induced LVH in both gp91phox-/- and wild-type mice. These data suggest a differential response of the cardiac Nox isoforms, gp91phox and Nox4, to Ang II versus pressure overload.  相似文献   
10.
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