144 research outputs found
Thin films of unsubstituted and fluorinated palladium phthalocyanines: structure and sensor response toward ammonia and hydrogen
In the present work, we study and compare the structure and sensing properties of thin films of unsubstituted palladium phthalocyanine (PdPc) and hexadecafluorosubstituted palladium phthalocyanine (PdPcF16). Thin films of PdPc and PdPcF16 were obtained by the method of organic molecular beam deposition and their structure was studied using UV-visible spectroscopy, X-ray diffraction and atomic force microscopy techniques. The electrical sensor response of PdPc films toward ammonia and hydrogen was investigated and compared with that of PdPcF16 films. The nature of interaction between the phthalocyanines films and some gaseous analyte molecules has been clarified using Quantum chemical (DFT) calculations
О МЕТОДЕ ОПРЕДЕЛЕНИЯ ПАРАМЕТРОВ ОЦЕНИВАНИЯ ПРОМЕЖУТОЧНЫХ УЗЛОВ ПЕРЕДАЧИ ДАННЫХ ПРИ МАРШРУТИЗАЦИИ В ИЕРАРХИЧЕСКИХ СЕТЯХ РАЗНОЙ ТОПОЛОГИИ
The method for estimating an intermediate node in networks with different topologies for routing problem and the method of estimation used communication channel are proposed in the article. The solution is based on the use of methods to assess the conditions of non-standard network protocols. Applies a number of criteria, covering the parameters describing the network in a limited presence of the administrator, as well as the history of use segment. In a decentralized network management estimation problem is to separate the control node in real time, and, ultimately, in the sequencing work network segment. This allows you to create a stable adapted route, taking into account the characteristics of each of its constituent units. Properties nodes may be adapted in numerical terms, responsible for load assembly, stability, bandwidth. This applies both to computer networks, and for managing networks. The results of the method are comprehensive assessment, which results in the treatment of accumulated statistics for making assessment of the route based on the task at hand. The concept of «problem» takes into account the type of data, and the conditions needed to make the best use of the channel for the problem of transmission of each data type.Предложен метод оценивания промежуточного узла в сетях с разной топологией для задачи маршрутизации и способ оценивания используемого канала связи. Решение основано на использовании методов оценки не относящихся к условиям стандартных сетевых протоколов. Применяется ряд критериев, охватывающих параметры, описывающие работу сети в условиях ограниченного присутствия администратора, а также историю использования узла (сегмента). В условиях децентрализации управления сетью задача оценивания состоит в выделении управляющего узла в реальном времени, а, в конечном счёте, в упорядочивании работы сегмента сети. Это позволяет создать стабильный адаптированный маршрут, учитывающий особенности каждого из составляющих его узлов. Свойства узлов могут быть адаптированы в численных показателях, отвечающие за загруженность узла, стабильность, пропускную способность. Это применимо как для компьютерных вычислительных сетей, так и для сетевых структур управления. Результаты работы метода проходят комплексную оценку, в результате которой происходит обработка накопленной статистики для вынесения оценки маршрута с учетом выполняемой задачи. Понятие «задачи» учитывает тип передаваемых данных, и условия необходимые для наиболее оптимального использования канала для задачи передачи каждого типа данных
О МЕТОДЕ ВЫБОРА ПРОМЕЖУТОЧНЫХ УЗЛОВ ПЕРЕДАЧИ ДАННЫХ ДЛЯ МАРШРУТИЗАЦИИ В ИЕРАРХИЧЕСКИХ СЕТЯХ РАЗНОЙ ТОПОЛОГИИ
The method for determining the intermediate node in networkswith different topologies for the routing problem and the estimation method of the used communication channel are proposedin article. Uses a variety of criteria covering the parametersdescribing the network in a limited presence administrator, as well as a history of using node (segment).Предложен метод определения промежуточного узла в сетях с разной топологией для задачи маршрутизации и способоцениванияиспользуемогоканаласвязи. Применяется ряд критериев, охватывающих параметры, описывающие работу сети в условиях ограниченного присутствия администратора, а также историю использования узла (сегмента)
Effect of fluorosubstitution on the structure of single crystals, Effect of fluorosubstitution on the structure of single crystals,thin films and spectral properties of palladium phthalocyanines
In this work, the crystalline structure of single crystals grown by vacuum sublimation of unsubstituted palladium phthalocyanines (PdPc), its tetrafluorinated (PdPcF4) and hexadecafluorinated (PdPcF16) derivatives have been investigated using X-ray diffraction measurements. Two crystalline phases have been identified for PdPc; the molecules in both phases crystallize in stacks with herringbone arrangement in the monoclinic space groups (C2/c for -PdPc; P21/n for -PdPc). Both PdPcF4 and PdPcF16 crystallize in the triclinic P-1 space group, forming stacks of molecules in columnar arrangement with molecules in adjacent columns are aligned parallel to one another. X-ray diffraction measurements have also been used to elucidate the structural features and molecular orientation of thin films of PdPc, PdPcF4 and PdPcF16, grown by organic molecular beam deposition at different substrate temperatures. The effect of fluorosubstitution on UV-visible optical absorption and vibrational spectra of palladium phthalocyanine derivatives is also discussed
Serological Profiling of a Candida albicans Protein Microarray Reveals Permanent Host-Pathogen Interplay and Stage-Specific Responses during Candidemia
Candida albicans in the immunocompetent host is a benign member of the human microbiota. Though, when host physiology is disrupted, this commensal-host interaction can degenerate and lead to an opportunistic infection. Relatively little is known regarding the dynamics of C. albicans colonization and pathogenesis. We developed a C. albicans cell surface protein microarray to profile the immunoglobulin G response during commensal colonization and candidemia. The antibody response from the sera of patients with candidemia and our negative control groups indicate that the immunocompetent host exists in permanent host-pathogen interplay with commensal C. albicans. This report also identifies cell surface antigens that are specific to different phases (i.e. acute, early and mid convalescence) of candidemia. We identified a set of thirteen cell surface antigens capable of distinguishing acute candidemia from healthy individuals and uninfected hospital patients with commensal colonization. Interestingly, a large proportion of these cell surface antigens are involved in either oxidative stress or drug resistance. In addition, we identified 33 antigenic proteins that are enriched in convalescent sera of the candidemia patients. Intriguingly, we found within this subset an increase in antigens associated with heme-associated iron acquisition. These findings have important implications for the mechanisms of C. albicans colonization as well as the development of systemic infection
One size doesn’t fit all: cross-sectional associations between neighborhood walkability, crime and physical activity depends on age and sex of residents
Abstract
Background
Low-income African American adults are disproportionately affected by obesity and are also least likely to engage in recommended levels of physical activity (Flegal et al. JAMA 303(3):235-41, 2010; Tucker et al. Am J Prev Med 40(4):454-61, 2011). Moderate-to-vigorous physical activity (MVPA) is an important factor for weight management and control, as well as for reducing disease risk (Andersen et al. Lancet 368(9532):299-304, 2006; Boreham and Riddoch J Sports Sci 19(12):915-29, 2001; Carson et al. PLoS One 8(8):e71417, 2013). While neighborhood greenspace and walkability have been associated with increased MVPA, evidence also suggests that living in areas with high rates of crime limits MVPA. Few studies have examined to what extent the confluence of neighborhood greenspace, walkability and crime might impact MVPA in low-income African American adults nor how associations may vary by age and sex.
Methods
In 2013 we collected self-reported data on demographics, functional limitations, objective measures of MVPA (accelerometry), neighborhood greenspace (geographic information system), and walkability (street audit) in 791 predominantly African-American adults (mean age 56 years) living in two United States (U.S.) low-income neighborhoods. We also acquired data from the City of Pittsburgh on all crime events within both neighborhoods. Exposure: To examine cross-sectional associations of neighborhood-related variables (i.e., neighborhood greenspace, walkability and crime) with MVPA, we used zero-inflated negative binomial regression models. Additionally, we examined potential interactions by age (over 65 years) and sex on relationships between neighborhood variables and MVPA.
Results
Overall, residents engaged in very little to no MVPA regardless of where they lived. However, for women, but not men, under the age of 65 years, living in more walkable neighborhoods was associated with more time engaged in MVPA in (β = 0.55, p = 0.007) as compared to their counterparts living in less walkable areas. Women and men age 65 years and over spent very little time participating in MVPA regardless of neighborhood walkability. Neither greenspace nor crime was associated with MVPA in age-sex subgroups.
Conclusions
Neighborhood walkability may play a stronger role on MVPA than accessible greenspace or crime in low-income urban communities. Walkability may differentially impact residents depending on their age and sex, which suggests tailoring public health policy design and implementation according to neighborhood demographics to improve activity for all.http://deepblue.lib.umich.edu/bitstream/2027.42/135725/1/12889_2016_Article_3959.pd
Multiple Hepatic Regulatory Variants at the GALNT2 GWAS Locus Associated with High-Density Lipoprotein Cholesterol
Genome-wide association studies (GWASs) have identified more than 150 loci associated with blood lipid and cholesterol levels; however, the functional and molecular mechanisms for many associations are unknown. We examined the functional regulatory effects of candidate variants at the GALNT2 locus associated with high-density lipoprotein cholesterol (HDL-C). Fine-mapping and conditional analyses in the METSIM study identified a single locus harboring 25 noncoding variants (r2 > 0.7 with the lead GWAS variants) strongly associated with total cholesterol in medium-sized HDL (e.g., rs17315646, p = 3.5 × 10−12). We used luciferase reporter assays in HepG2 cells to test all 25 variants for allelic differences in regulatory enhancer activity. rs2281721 showed allelic differences in transcriptional activity (75-fold [T] versus 27-fold [C] more than the empty-vector control), as did a separate 780-bp segment containing rs4846913, rs2144300, and rs6143660 (49-fold [AT– haplotype] versus 16-fold [CC+ haplotype] more). Using electrophoretic mobility shift assays, we observed differential CEBPB binding to rs4846913, and we confirmed this binding in a native chromatin context by performing chromatin-immunoprecipitation (ChIP) assays in HepG2 and Huh-7 cell lines of differing genotypes. Additionally, sequence reads in HepG2 DNase-I-hypersensitivity and CEBPB ChIP-seq signals spanning rs4846913 showed significant allelic imbalance. Allelic-expression-imbalance assays performed with RNA from primary human hepatocyte samples and expression-quantitative-trait-locus (eQTL) data in human subcutaneous adipose tissue samples confirmed that alleles associated with increased HDL-C are associated with a modest increase in GALNT2 expression. Together, these data suggest that at least rs4846913 and rs2281721 play key roles in influencing GALNT2 expression at this HDL-C locus
Association analyses of East Asian individuals and trans-ancestry analyses with European individuals reveal new loci associated with cholesterol and triglyceride levels
Large-scale meta-analyses of genome-wide association studies (GWAS) have identified >175 loci associated with fasting cholesterol levels, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). With differences in linkage disequilibrium (LD) structure and allele frequencies between ancestry groups, studies in additional large samples may detect new associations. We conducted staged GWAS meta-analyses in up to 69,414 East Asian individuals from 24 studies with participants from Japan, the Philippines, Korea, China, Singapore, and Taiwan. These meta-analyses identified (P < 5 × 10-8) three novel loci associated with HDL-C near CD163-APOBEC1 (P = 7.4 × 10-9), NCOA2 (P = 1.6 × 10-8), and NID2-PTGDR (P = 4.2 × 10-8), and one novel locus associated with TG near WDR11-FGFR2 (P = 2.7 × 10-10). Conditional analyses identified a second signal near CD163-APOBEC1. We then combined results from the East Asian meta-analysis with association results from up to 187,365 European individuals from the Global Lipids Genetics Consortium in a trans-ancestry meta-analysis. This analysis identified (log10Bayes Factor ≥6.1) eight additional novel lipid loci. Among the twelve total loci identified, the index variants at eight loci have demonstrated at least nominal significance with other metabolic traits in prior studies, and two loci exhibited coincident eQTLs (P < 1 × 10-5) in subcutaneous adipose tissue for BPTF and PDGFC. Taken together, these analyses identified multiple novel lipid loci, providing new potential therapeutic targets
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