全文获取类型
收费全文 | 167篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
174篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 12篇 |
2012年 | 7篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 14篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2001年 | 9篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1976年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有174条查询结果,搜索用时 15 毫秒
81.
Syed Tasleem Raza Shania Abbas Faisal Ahmed Jalees Fatima Zeashan Haider Zaidi Farzana Mahdi 《Gene》2012
Background
Type 2 diabetes mellitus is a multifactorial and polygenic disease, which is considered as a major life threatening problem all over the world. There has been a worldwide effort in the identification of susceptibility genes for type 2 diabetes mellitus and its complications. At present, adequate data is not available dealing with MTHFR (rs1801133) and PPARγ2 (rs1801282) gene polymorphisms and its association with type 2 diabetes mellitus cases among north Indian populations. Thus, we conceived the need for further studies to investigate MTHFR and PPARγ2 gene polymorphisms and their susceptibility to type 2 diabetes mellitus in north Indian population.Materials and methods
In this study, a total 175 subjects including 87 type 2 diabetes mellitus cases and 88 controls were enrolled. MTHFR and PPARγ2 gene polymorphisms in the cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR–RFLP).Results
The MTHFR gene CC, CT, TT genotype frequencies obtained were 40%, 43%, and 17% in type 2 diabetes mellitus cases and 56%, 29%, and 15% in healthy controls respectively. The OR for CC was 0.54 (95%CI 0.29–0.98, P = 0.041, χ2 = 4.18, power = 0.98), for CT 1.76 (95%CI 0.94–3.30, P = 0.07, χ2 = 3.2, power = 0.96), and for TT 1.2 (95%CI 0.53–2.70, P = 0.66, χ2 = 0.198, power = 0.76). The PPARγ2 gene GG CG, CC genotype frequencies obtained were 28%, 41%, and 31% in cases and 40%, 39%, and 21% in healthy controls respectively. OR for GG was 0.58 (95%CI 0.30–1.09, P = 0.08, χ2 = 2.9, power = 0.96), for CG 1.12 (95%CI 0.61–2.05, P = 0.71, χ2 = 0.137, power = 0.778), and for CC 1.63 (95%CI 0.82–3.23, P = 0.156, χ2 = 2.01, power = 0.92).Conclusion
It might be recommended that MTHFR CC genotype seems to be a good marker for the early identification of population at risk of type 2 diabetes mellitus. While we have detected significant difference in allelic frequencies of PPARγ2 C (Proline) and G (Alanine), but at genotypic level significant difference was not detected in this case–control study. Further study with larger groups may be required to validate the study. 相似文献82.
83.
目的了解深圳市人民医院重症监护病房分离菌超广谱β-内酰胺酶(ESBLs)的检出率及其基因型分布情况。方法收集来自重症监护病房大肠埃希菌和肺炎克雷伯菌分离株48株,采用CLSI推荐的表型确证方法筛选出ESBLs株,并利用PCR及DNA测序法分析产酶菌株的ESBL基因型。结果(1)48分离株菌中共检出产ESBLs菌24株,阳性率为50.0%。(2)产酶菌中93.8%(15/16)的大肠埃希菌和87.5%(7/8)的肺炎克雷伯菌分别检出CTX-M基因;其中72.7%(16/22)为CTX-M-14。6株肺炎克雷伯菌检出SHV基因,其中3株为SHV-11型,另3株为SHV-12型,6株含SHV基因的肺炎克雷伯菌中5株合并CTX-M基因。而所有大肠埃希菌株均未检出SHV基因。所有产酶菌中,分别有10株大肠埃希菌和2株肺炎克雷伯菌检出TEM-1基因,其中1株大肠埃希菌只检出TEM-1基因,未检出SHV型或CTX-M型基因。结论重症监护病房分离菌ESBLs检出率高,以CTX-M-14为主要基因型。 相似文献
84.
目的了解武汉同济医院2004年至2010年临床分离多重耐药菌株的检出情况。方法对临床分离菌株,采用纸片扩散法按统一的方案进行药敏试验。按照CLSI 2009年标准进行判断。结果 2004年至2010年该院耐甲氧西林金葡菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRSCN)的检出率分别在35.6%~63.8%和21.5%~61.4%。2004年至2010年共检出36株耐万古霉素肠球菌(VRE)。大肠埃希菌产ESBLs株检出率在29.6%~81.7%,肺炎克雷伯菌产ESBLs株检出率在36.0%~56.6%,产酸克雷伯产ESBLs株检出率在35.3%~67.4%,奇异变形杆菌产ESBLs株检出率在0~26.2%。自2005年起每年均有泛耐药的铜绿假单胞菌和鲍曼不动杆菌的检出。结论该院2004年至2010年多重耐药菌株呈增多趋势,尤其是VRE和泛耐药的铜绿假单胞菌和鲍曼不动杆菌的出现,给临床治疗带来了严峻挑战。 相似文献
85.
The study of gene-based genetic associations has gained conceptual popularity recently. Biologic insight into the etiology of a complex disease can be gained by focusing on genes as testing units. Several gene-based methods (e.g., minimum p-value (or maximum test statistic) or entropy-based method) have been developed and have more power than a single nucleotide polymorphism (SNP)-based analysis. The objective of this study is to compare the performance of the entropy-based method with the minimum p-value and single SNP–based analysis and to explore their strengths and weaknesses. Simulation studies show that: 1) all three methods can reasonably control the false-positive rate; 2) the minimum p-value method outperforms the entropy-based and the single SNP–based method when only one disease-related SNP occurs within the gene; 3) the entropy-based method outperforms the other methods when there are more than two disease-related SNPs in the gene; and 4) the entropy-based method is computationally more efficient than the minimum p-value method. Application to a real data set shows that more significant genes were identified by the entropy-based method than by the other two methods. 相似文献
86.
Sverre Kobro Linda Søreide Endre Djønne Trond Rafoss Gunnhild Jaastad Peter Witzgall 《Population Ecology》2003,45(1):25-30
Masting of rowan Sorbus aucuparia L. has been studied in 45 sites in southern Norway for 22 years. We present data on the year-to-year variation in fruit setting
of rowan, and show that masting is spatially synchronous in Norway and probably all over Fennoscandia. The apple fruit moth
Argyresthia conjugella Zeller is an important seed predator on rowan. We present data on the abundance of apple fruit moth in rowanberries during
these years and discuss the consequences of masting and intermasting of rowan for apple fruit moth as a pest of apple. We
conclude that growth and climate have little impact on flowering intensity and suggest that masting of rowan is an adaptive
defense against seed predation and a new example of predator satiation: intermast years inhibit predators and prepare the
rowan for the subsequent mast.
Received: September 3, 2001 / Accepted: February 24, 2003 相似文献
87.
Gillian Barker 《Biology & philosophy》2008,23(1):1-25
Two critiques of simple adaptationism are distinguished: anti-adaptationism and extended adaptationism. Adaptationists and
anti-adaptationists share the presumption that an evolutionary explanation should identify the dominant simple cause of the
evolutionary outcome to be explained. A consideration of extended-adaptationist models such as coevolution, niche construction
and extended phenotypes reveals the inappropriateness of this presumption in explaining the evolution of certain important
kinds of features—those that play particular roles in the regulation of organic processes, especially behavior. These biological
or behavioral ‘levers’ are distinctively available for adaptation and exaptation by their possessors and for co-optation by
other organisms. As a result they are likely to result from a distinctive and complex type of evolutionary process that conforms
neither to simple adaptationist nor to anti-adaptationist styles of explanation. Many of the human features whose evolutionary
explanation is most controversial belong to this category, including the female orgasm.
相似文献
Gillian BarkerEmail: |
88.
89.
Freidlin B 《Biometrics》1999,55(1):264-267
By focusing on a confidence interval for a nuisance parameter, Berger and Boos (1994, Journal of the American Statistical Association 89, 1012-1016) proposed new unconditional tests. In particular, they showed that, for a 2 x 2 table, this procedure generally was more powerful than Fisher's exact test. This paper utilizes and extends their approach to obtain unconditional tests for combining several 2 x 2 tables and testing for trend and homogeneity in a 2 x K table. The unconditional procedures are compared to the conditional ones by reanalyzing some published biomedical data. 相似文献
90.