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排序方式: 共有136条查询结果,搜索用时 15 毫秒
21.
Neil Caporaso Fangyi Gu Nilanjan Chatterjee Jin Sheng-Chih Kai Yu Meredith Yeager Constance Chen Kevin Jacobs William Wheeler Maria Teresa Landi Regina G. Ziegler David J. Hunter Stephen Chanock Susan Hankinson Peter Kraft Andrew W. Bergen 《PloS one》2009,4(2)
The contribution of common genetic variation to one or more established smoking behaviors was investigated in a joint analysis of two genome wide association studies (GWAS) performed as part of the Cancer Genetic Markers of Susceptibility (CGEMS) project in 2,329 men from the Prostate, Lung, Colon and Ovarian (PLCO) Trial, and 2,282 women from the Nurses'' Health Study (NHS). We analyzed seven measures of smoking behavior, four continuous (cigarettes per day [CPD], age at initiation of smoking, duration of smoking, and pack years), and three binary (ever versus never smoking, ≤10 versus >10 cigarettes per day [CPDBI], and current versus former smoking). Association testing for each single nucleotide polymorphism (SNP) was conducted by study and adjusted for age, cohabitation/marital status, education, site, and principal components of population substructure. None of the SNPs achieved genome-wide significance (p<10−7) in any combined analysis pooling evidence for association across the two studies; we observed between two and seven SNPs with p<10−5 for each of the seven measures. In the chr15q25.1 region spanning the nicotinic receptors CHRNA3 and CHRNA5, we identified multiple SNPs associated with CPD (p<10−3), including rs1051730, which has been associated with nicotine dependence, smoking intensity and lung cancer risk. In parallel, we selected 11,199 SNPs drawn from 359 a priori candidate genes and performed individual-gene and gene-group analyses. After adjusting for multiple tests conducted within each gene, we identified between two and five genes associated with each measure of smoking behavior. Besides CHRNA3 and CHRNA5, MAOA was associated with CPDBI (gene-level p<5.4×10−5), our analysis provides independent replication of the association between the chr15q25.1 region and smoking intensity and data for multiple other loci associated with smoking behavior that merit further follow-up. 相似文献
22.
Martina K Caporaso M Tagliapietra S Heropoulos G Rosati O Cravotto G 《Carbohydrate research》2011,346(17):2677-2682
New highly soluble β-aminoalcohol β-cyclodextrin (β-CD) derivatives have been synthesized via nucleophilic epoxide opening reactions with mono-6-amino mono-6-deoxy-permethyl-β-CD and mono-6-amino mono-6-deoxy-β-CD. The binding properties of the β-CD were enhanced by linking aminoalcohol subunits which caused its solubility to improve markedly. The reaction conditions were optimised using microwave irradiation giving moderate-to-good yields with a series of epoxides. A regioselective epoxide opening reaction was observed in the reaction with styrene oxide while the stereoselectivity was strictly dependent on substrate structure. 相似文献
23.
The use of the photochemical reflectance index (PRI) as a promising proxy of light use efficiency (LUE) has been extensively studied, and some issues have been identified, notably the sensitivity of PRI to leaf pigment composition and the variability in PRI response to LUE because of stress. In this study, we introduce a method that enables us to track the short‐term PRI response to LUE changes because of photosynthetically active radiation (PAR) changes. The analysis of these short‐term relationships between PRI and LUE throughout the growing season in two species (Quercus robur L. and Fagus sylvatica L.) under two different soil water statuses showed a clear change in PRI response to LUE, which is related to leaf pigment content. The use of an estimated or approximated PRI0, defined as the PRI of perfectly dark‐adapted leaves, allowed us to separate the PRI variability due to leaf pigment content changes and the physiologically related PRI variability over both daily (PAR‐related) and seasonal (soil water content‐related) scales. The corrected PRI obtained by subtracting PRI0 from the PRI measurements showed a good correlation with the LUE over both of the species, soil water statuses and over the entire growing season. 相似文献
24.
Michael J. Rothrock Jr. Kelli L. Hiett John Gamble Andrew C. Caudill Kellie M. Cicconi-Hogan J. Gregory Caporaso 《Journal of visualized experiments : JoVE》2014,(94)
The efficacy of DNA extraction protocols can be highly dependent upon both the type of sample being investigated and the types of downstream analyses performed. Considering that the use of new bacterial community analysis techniques (e.g., microbiomics, metagenomics) is becoming more prevalent in the agricultural and environmental sciences and many environmental samples within these disciplines can be physiochemically and microbiologically unique (e.g., fecal and litter/bedding samples from the poultry production spectrum), appropriate and effective DNA extraction methods need to be carefully chosen. Therefore, a novel semi-automated hybrid DNA extraction method was developed specifically for use with environmental poultry production samples. This method is a combination of the two major types of DNA extraction: mechanical and enzymatic. A two-step intense mechanical homogenization step (using bead-beating specifically formulated for environmental samples) was added to the beginning of the “gold standard” enzymatic DNA extraction method for fecal samples to enhance the removal of bacteria and DNA from the sample matrix and improve the recovery of Gram-positive bacterial community members. Once the enzymatic extraction portion of the hybrid method was initiated, the remaining purification process was automated using a robotic workstation to increase sample throughput and decrease sample processing error. In comparison to the strict mechanical and enzymatic DNA extraction methods, this novel hybrid method provided the best overall combined performance when considering quantitative (using 16S rRNA qPCR) and qualitative (using microbiomics) estimates of the total bacterial communities when processing poultry feces and litter samples. 相似文献
25.
Dawn Field Peter Sterk Renzo Kottmann J. Wim De Smet Linda Amaral-Zettler Guy Cochrane James R. Cole Neil Davies Peter Dawyndt George M. Garrity Jack A. Gilbert Frank Oliver Gl?ckner Lynette Hirschman Hans-Peter Klenk Rob Knight Nikos Kyrpides Folker Meyer Ilene Karsch-Mizrachi Norman Morrison Robert Robbins Inigo San Gil Susanna Sansone Lynn Schriml Tatiana Tatusova Dave Ussery Pelin Yilmaz Owen White John Wooley Gregory Caporaso 《Standards in genomic sciences》2014,9(3):599-601
26.
ARMAND J. de RICQLÈS KEVIN PADIAN JOHN R. HORNER HÉLÈNE FRANCILLON-VIEILLOT 《Zoological Journal of the Linnean Society》2000,129(3):349-385
Thin sections from long bones of specimens representing pterosaurs ranging from the Early Jurassic to the latest Cretaceous provide a profile of bone histology across a range of sizes, skeletal elements, growth stages, and phylogenetic positions. Most pterosaur bone is fibro-lamellar, organized in an unusual way that suggests high growth rates through ontogeny. Fibro-lamellar deposits are finished by a relatively abrupt deceleration or cessation of growth represented by lamellar, poorly vascularized subperiosteal bone in what appear to be adults. Pterosaurs had the thinnest bone walls of any tetrapods; they complemented high rates of periosteal deposition with almost equally high rates of endosteal erosion. Pterosaurs show a great variety of histologic features that include articular calcified cartilage, sub-chondral bone plates, trabecular bone struts and related internal supports, and secondary deposition and remodeling of bone. They remodeled their bones internally by (1) depositing endosteal bone coatings on the inner cortex and over struts of pre-existing internal bone, (2) secondarily filling bone spaces, and (3) Haversian reworking. The construction of these struts reflects both developmental patterns of bone construction and biomechanical function. Alternating plywood-like layers of bone, heretofore undescribed in tetrapods, provided strength, as did the obliquely oriented system of reticular blood vessels in the bones. The distribution and ontogenetic features of pterosaur bone tissues, when combined with other evidence, suggest generally high growth rates, high metabolic levels, altricial birth, and extended parental care. 相似文献
27.
A stable deletion derivative pNH602 was obtained when the recently described higher-copy-number point mutant pNH601 of plasmid R6K was introduced to a minicells-producing strain of Escherichia coli. The size of plasmid pNH602 is 18.8 Mg/mol as determined by electron microscopy. The 7.2 Mg/mol fragment of R6K genome missing in pNH602 carries the Smr-determinant and the region finO and, according to the results of restriction analysis, it includes one EcoRI site. With its radioisotopically determined 33 copies of pNH602 per E. coli K-12 chromosome (npc), representing a 23% increase of the point mutant pNH601 and 150% enhancement of R6K npc, plasmid pNH602 differs from another closely related R6K deletion derivative pAS3 of the same size which exhibits only 20 npc. Both pNH602 and pAS3 plasmids are conjugative. 相似文献
28.
中国幽灵蛛属一新种(蜘蛛目:幽灵蛛科) 总被引:1,自引:0,他引:1
本文记述了中国幽灵蛛科Pholcidae幽灵蛛属Pholcus蜘蛛一新种;太白幽灵蛛,新种Pholcus taibaiensis sp. nov,采自陕西省太白山自然保护区。模式标本分别保存在西安师范学院生物系和河北教育学院生物系。 相似文献
29.
NONO ubiquitination is mediated by FBW7 and GSK3 β via a degron lost upon chromosomal rearrangement in cancer 下载免费PDF全文
30.
Pornchai Sithisarankul Paolo Vineis Daehee Kang Nathaniel Rothman Neil Caporaso Paul Strickland 《Biomarkers》1997,2(4):217-221
Humans are exposed to polycyclic aromatic hydrocarbons PAHs from various occupational, dietary, environmental and medicinal sources. We measured 1 hydroxypyrene glucuronide 1 OHP gluc concentration in urines from male non smokers n = 50 , smokers of blond tobacco n = 31 , smokers of black tobacco n = 16 , and pipe smokers n = 3 . Immunoaffinity chromatography was used as a preparative step and synchronous fluorescence spectroscopy as the quantitation method. The concentration of 1 OHP gluc in urine from smokers mean SE: 1.04 0.13 pmol ml-1 urine was significantly higher than in urine from non smokers 0.55 0.05 pmol ml-1 urine by the Wilcoxon rank sum test non smokers versus all smokers, p = 0.001; vs black tobacco smokers, p = 0.001; vs blond tobacco smokers, p = 0.007 . Urinary 1 OHP gluc concentration among subjects who had consumed roasted, grilled or broiled meat within the past 24 h was elevated compared with those who had not p = 0.025 . Multiple linear regression showed significant associations of urinary 1 OHP gluc with number of cigarettes smoked p = 0.002 and consumption of roasted, grilled or broiled meat p = 0.028 . Systemic CYP1A2 activity estimated by caffeine metabolism was significantly correlated with urinary 1 OHP gluc concentration. However, this association was probably due to cigarette smoking, since adjusting for cigarette smoking by multiple linear regression made the association between urinary 1 OHP gluc and CYP1A2 phenotype non significant. These results further support the use of urinary 1 OHP gluc as a biomarker of recent pyrene exposure through inhalation or diet. 相似文献