98 research outputs found
Study on the Modified triphenyl tetrazolium chloride – dehydrogenase activity (TTC-DHA) Method in Determination of bioactivity in the up-flow aerated bio-activated carbon filter
The study applied triphenyl tetrazolium chloride-dehydrogenase activity (TTC-DHA) method to detect the activities of attached biofilm on bio-activated carbon (BAC) samples in the up-flow aerated biological activated carbon filter (UABACF) treating textile secondary effluent. Modification to the conventional TTC-DHA determination method was proposed. In the modification, BAC samples were used directly to measure TTC-DHA without pre-separating the attached biofilm from carbon samples. After modification, the mean values of biofilm TTC-DHA activities for the BAC samples at different heights of the biofilter were 25 to 193 times higher than those measured in conventional way. In addition, the microbial activity distribution related more closely to substrate removal along the height of the reactor after modification. The results indicated that high activity of the bacteria that are firmly fixed on the porous surface of the media would be ignored during pre-separation of the attached biofilm from media surface. The study also indicated the influence of granular activated carbon (GAC) adsorption on the bio-activity of attached biofilm. GAC adsorption was favorable in the improvement of the activities within the biofilter, especially when the attached films were destroyed. The modification of TTC-DHA determination method made this technique more convenient and accurate in activity measurement of biofilm fixed on porous surface structured activated carbon.Keywords: Up-flow, aerated bio-filter, BAC, TTC-DHA, bioactivit
Predicting Cloud Performance Using Real-time VM-level Metrics
The vast range of cloud service offerings can easily overwhelm users and cause them to select ones that are unsuitable for their needs. As such, the literature has a number of proposals to predict application performance based on a history of executing a certain application or benchmark. However, this requires significant cost to pre-run the application on different service levels before identifying the most suitable one. We propose a machine learning model that enables a cloud user to select the optimal cloud service based on real-time execution without the need to do an exhaustive search. We develop and test this model using a popular benchmark suite on Microsoft Azure, a leading cloud provider. The key insight of this work is that fluctuations in rather than the absolute amount of utilization levels of CPU and memory can be strongly indicative of how well an application is executing
Citrinin Derivatives From Penicillium Citrinum Y34 That Inhibit α-Glucosidase and ATP-Citrate Lyase
Two new citrinin dimers bearing a 6,6-spiroketal moiety (1 and 2) and four known analogues (3–6), together with 18 known citrinin monomers (7–24), were isolated from the culture of hydrothermal vent-associated fungus Penicillium citrinum Y34. Their structures were identified by extensive spectroscopic analyses, 13C NMR calculation in combination with DP4+, linear correlation coefficient (R2), and mean absolute error (MAE) values analyses, and electronic circular dichroism (ECD) calculation. The α-glucosidase and ATP-citrate lyase (ACL) inhibitory activities of isolated compounds were evaluated. Compounds 1, 3, and 12 displayed moderate α-glucosidase inhibitory activities with IC50 values of 239.8, 176.2, and 424.4 μM, respectively. Enzyme kinetics investigations of 1 and 3 suggested their non-competitive inhibition of α-glucosidase with Ki values of 204.3 and 212.7 μM, respectively. Meanwhile, compound 4 showed significant ACL inhibitory potential with an IC50 value of 17.4 μM. Furthermore, the interactions of 1, 3, and 12 with α-glucosidase and 4 with ACL were investigated by molecular docking assay. This study demonstrates that citrinins, especially for their dimers, could be potential lead compounds for the development of new agents for the treatment of metabolic diseases
Household air pollution and epigenetic aging in Xuanwei, China
BACKGROUND: Household air pollution (HAP) from indoor combustion of solid fuel is a global health burden linked to lung cancer. In Xuanwei, China, lung cancer rate for nonsmoking women is among the highest in the world and largely attributed to high levels of polycyclic aromatic hydrocarbons (PAHs) that are produced from combustion of smoky (bituminous) coal used for cooking and heating. Epigenetic age acceleration (EAA), a DNA methylation-based biomarker of aging, has been shown to be highly correlated with biological processes underlying the susceptibility of age-related diseases. We aim to assess the association between HAP exposure and EAA. METHODS: We analyzed data from 106 never-smoking women from Xuanwei, China. Information on fuel type was collected using a questionnaire, and validated exposure models were used to predict levels of 43 HAP constituents. Exposure clusters were identified using hierarchical clustering. EAA was derived for five epigenetic clocks defined as the residuals resulting from regressing each clock on chronological age. We used generalized estimating equations to test associations between exposure clusters derived from predicted levels of HAP exposure, ambient 5-methylchrysene (5-MC), a PAH previously found to be associated with risk of lung cancer, and EAA, while accounting for repeated-measurements and confounders. RESULTS: We observed an increase in GrimAge EAA for clusters with 31 and 33 PAHs reflecting current (β = 0.77 y per standard deviation (SD) increase, 95 % CI:0.36,1.19) and childhood (β = 0.92 y per SD, 95 % CI:0.40,1.45) exposure, respectively. 5-MC (ng/m 3-year) was found to be associated with GrimAge EAA for current (β = 0.15 y, 95 % CI:0.05,0.25) and childhood (β = 0.30 y, 95 % CI:0.13,0.47) exposure. CONCLUSIONS: Our findings suggest that exposure to PAHs from indoor smoky coal combustion, particularly 5-MC, is associated with GrimAge EAA, a biomarker of mortality
The DNA Methylome of Human Peripheral Blood Mononuclear Cells
Analysis across the genome of patterns of DNA methylation reveals a rich landscape of allele-specific epigenetic modification and consequent effects on allele-specific gene expression
Long-term trends of chemical characteristics and sources of fine particle in Foshan City, Pearl River Delta: 2008–2014
Вихретоковый анизотропный термоэлектрический первичный преобразователь лучистого потока
Представлена оригинальная конструкция первичного преобразователя лучистого потока, который может служить основой для создания приемника неселективного излучения с повышенной чувствительностью
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