AIM: To determine whether weight-loss diets varying in macronutrients modulate the genetic effect of hepatocyte nuclear factor 1alpha (HNF1A) rs7957197 on weight loss and improvement of insulin resistance. MATERIALS AND METHODS: We analysed the interaction between HNF1A rs7957197 and weight-loss diets with regard to weight loss and insulin resistance improvement among 722 overweight/obese adults from a 2-year randomized weight-loss trial, the POUNDS Lost trial. The findings were replicated in another independent 2-year weight-loss trial, the Dietary Intervention Randomized Controlled Trial (DIRECT), in 280 overweight/obese adults. RESULTS: In the POUNDS Lost trial, we found that a high-fat diet significantly modified the genetic effect of HNF1A on weight loss and reduction in waist circumference (P for interaction = .006 and .005, respectively). Borderline significant interactions for fasting insulin and insulin resistance (P for interaction = .07 and .06, respectively) were observed. We replicated the results in DIRECT. Pooled results showed similar significant interactions with weight loss, waist circumference reduction, and improvement in fasting insulin and insulin resistance (P values for interaction = .001, .005, .02 and .03, respectively). Greater decreases in weight, waist circumference, fasting insulin level and insulin resistance were observed in participants with the T allele compared to those without the T allele in the high-fat diet group (P = .04, .03 and .01, respectively). CONCLUSIONS: Our replicable findings provide strong evidence that individuals with the HNF1A rs7957197 T allele might obtain more benefits in weight loss and improvement of insulin resistance by choosing a hypocaloric and high-fat diet.
This paper for the first time prototypes and compares the homodyne and heterodyne terahertz dielectric sensors for lab-on-chip applications. The homodyne sensor consists of a multiplier chain, a balun-based power divider, an on-chip transducer, and IQ mixers. Differently, the heterodyne sensor requires an additional multiplier chain; however, it waives one mixer and a power divider, leading to reduced losses and alleviated power consumption. Fabricated using 0.13 µm SiGe BiCMOS technology, the homodyne and heterodyne sensors take 4 mm 2 and 5.2 mm 2 , and consume 400 mW and 499 mW, respectively. By experiments, both designed homodyne and heterodyne sensors can effectively sense the dielectric parameters of the samples. Moreover, the heterodyne sensor can address the DC offset issues with merely 99 mW additional power.
In this study, mineral oil–water fluid miscibility without and with the addition of surfactant-decorated nanoparticles is experimentally and theoretically studied. First, three series of interfacial tension (IFT) tests are conducted using a spinning drop tensiometer (SDT) with the addition of hexadecyltrimethylammonium bromide (CTAB) surfactant-decorated SiO2 nanoparticles at different concentrations. Second, a new comprehensive thermodynamic model is developed to describe the fluid miscibility without and with the addition of these surfactant-decorated nanoparticles, which is also applied theoretically to reveal how the surfactant-decorated nanoparticles contribute to the thermodynamic miscibility state. The thermodynamic model developed is proven to be accurate and physically meaningful by comparing its calculated free energy of mixing with the experimental results and examples from the literature. A series of optimum conditions for the improvement of fluid miscibility by the addition of such surfactant-decorated nanoparticles are determined: a lower temperature, a higher pressure, more wetting conditions, a smaller nanoparticle radius (rNP < 40 nm), a larger surfactant concentration, and a nanoparticle concentration in the range of 0.5–0.6 wt.%. It should be noted that a higher nanoparticle concentration is required with the addition of more CTAB surfactants in order to reach the most miscible state. Moreover, the effect of surfactant concentration on the miscibility development is found to be independent of the nanoparticle radius, whereas the optimum nanoparticle concentration is reduced with increasing particle size.
Digital Elevation Model (DEM) is one of the most important controlling factors determining the simulation accuracy of hydraulic models. However, the currently available global topographic data is confronted with limitations for application in 2-D hydraulic modeling, mainly due to the existence of vegetation bias, random errors and insufficient spatial resolution. A hydraulic correction method (HCM) for the SRTM DEM is proposed in this study to improve modeling accuracy. Firstly, we employ the global vegetation corrected DEM (i.e. Bare-Earth DEM), developed from the SRTM DEM to include both vegetation height and SRTM vegetation signal. Then, a newly released DEM, removing both vegetation bias and random errors (i.e. Multi-Error Removed DEM), is employed to overcome the limitation of height errors. Last, an approach to correct the Multi-Error Removed DEM is presented to account for the insufficiency of spatial resolution, ensuring flow connectivity of the river networks. The approach involves: (a) extracting river networks from the Multi-Error Removed DEM using an automated algorithm in ArcGIS; (b) correcting the location and layout of extracted streams with the aid of Google Earth platform and Remote Sensing imagery; and (c) removing the positive biases of the raised segment in the river networks based on bed slope to generate the hydraulically corrected DEM. The proposed HCM utilizes easily available data and tools to improve the flow connectivity of river networks without manual adjustment. To demonstrate the advantages of HCM, an extreme flood event in Huifa River Basin (China) is simulated on the original DEM, Bare-Earth DEM, Multi-Error removed DEM, and hydraulically corrected DEM using an integrated hydrologic-hydraulic model. A comparative analysis is subsequently performed to assess the simulation accuracy and performance of four different DEMs and favorable results have been obtained on the corrected DEM. (C) 2018 Elsevier B.V. All rights reserved.
We perform computational studies of static packings of a variety of nonspherical particles including circulo-lines, circulo-polygons, ellipses, asymmetric dimers, dumbbells, and others to determine which shapes form packings with fewer contacts than degrees of freedom (hypostatic packings) and which have equal numbers of contacts and degrees of freedom (isostatic packings), and to understand why hypostatic packings of nonspherical particles can be mechanically stable despite having fewer contacts than that predicted from naive constraint counting. To generate highly accurate force- and torque-balanced packings of circulo-lines and cir-polygons, we developed an interparticle potential that gives continuous forces and torques as a function of the particle coordinates. We show that the packing fraction and coordination number at jamming onset obey a masterlike form for all of the nonspherical particle packings we studied when plotted versus the particle asphericity A, which is proportional to the ratio of the squared perimeter to the area of the particle. Further, the eigenvalue spectra of the dynamical matrix for packings of different particle shapes collapse when plotted at the same A. For hypostatic packings of nonspherical particles, we verify that the number of “quartic” modes along which the potential energy increases as the fourth power of the perturbation amplitude matches the number of missing contacts relative to the isostatic value. We show that the fourth derivatives of the total potential energy in the directions of the quartic modes remain nonzero as the pressure of the packings is decreased to zero. In addition, we calculate the principal curvatures of the inequality constraints for each contact in circulo-line packings and identify specific types of contacts with inequality constraints that possess convex curvature. These contacts can constrain multiple degrees of freedom and allow hypostatic packings of nonspherical particles to be mechanically stable.
Exceedingly high levels of PM2.5 with complex chemical composition occur frequently in China. It has been speculated whether anthropogenic PM2.5 may significantly contribute to ice-nucleating particles (INP). However, few studies have focused on the ice-nucleating properties of urban particles. In this work, two ice-nucleating droplet arrays have been used to determine the atmospheric number concentration of INP (N-INP) in the range from 6 to 25 degrees C in Beijing. No correlations between N-INP and either PM2.5 or black carbon mass concentrations were found, although both varied by more than a factor of 30 during the sampling period. Similarly, there were no correlations between N-INP and either total particle number concentration or number concentrations for particles with diameters > 500 nm. Furthermore, there was no clear difference between day and night samples. All these results indicate that Beijing air pollution did not increase or decrease INP concentrations in the examined temperature range above values observed in nonurban areas; hence, the background INP concentrations might not be anthropogenically influenced as far as urban air pollution is concerned, at least in the examined temperature range.
Strain HG-7 was identified as Pseudomonas sp.through 16s rRNA gene sequence analysis.The aerobic denitrification ability of strain HG-7 was further proved by the existence of the napA and nirK genes.Further studies showed that the optimal carbon resources for strain HG-7 were sodium acetate and sodium succinate,the optimal C/N ratio was 6-10,and the suitable temperature was 26-30℃.At this condition,with an initial nitrate nitrogen of 100 mg/L,98% of nitrate could be removed in 48 hours and the amount of nitrite accumulation was very small.Moreover,with nitrite as the sole nitrogen source,100% of nitrite could be removed at lower nitrite concentration.But the nitrite nitrogen removal rate was about 40% when the nitrite concentration increased to 91.4 mg/L,indicating that high nitrite concentration was harmful for aerobic denitrification by strain HG-7.The strain HG-7 has great potential to be used for biological nitrogen removal,which was particularly significant for actual wastewater treatment processes.以筛选分离得到的好氧反硝化菌HG-7为研究对象,经过16S rRNA同源性分析,初步鉴定该菌株为假单胞菌属(Pseudomonas sp.)。对菌株HG-7反硝化功能基因的扩增结果表明,菌体HG-7内存在好氧反硝化功能基因napA和nirK,证实该细菌为好氧反硝化细菌。对菌株 的脱氮特性和影响因素的研究表明,以硝酸盐氮为氮源时,菌株的最适碳源为乙酸钠和丁二酸钠,最佳C/N比为6~10,最适宜的温度范围为26~30℃。在 上述条件下,菌株HG-7的好氧反硝化活性较高,48小时内对100 mg/L硝酸盐氮的去除率可达98%,且在反应过程中亚硝酸盐氮积累量较低。以亚硝酸氮为唯一氮源时,低浓度条件下可实现100%的氮素去除率;高浓度条 件下,脱氮速率则受到明显的抑制,对91.4 mg/L的亚硝酸盐氮氮去除率约为40%。因此,将该菌株应用于废水的脱氮处理,可实现氮素的有效去除,具有潜在的应用价值。
