The Successful Construction of a High Gravity Dam on Complex Rock Formation

This paper presents an analysis of the stability against sliding of a gravity dam built on a layered rock formation. During the design of this dam, detailed studies of the dam foundation were carried out from a viewpoint of rock mechanics, including laboratory and in-situ tests of the mechanical properties of rocks, calculations by the theory of limit equilibrium and FEM, as well as model tests. Based on these studies, the dam type was selected

First-Principles Study of the Band Gap Structure of Oxygen-Passivated Silicon Nanonets

A net-like nanostructure of silicon named silicon nanonet was designed and oxygen atoms were used to passivate the dangling bonds. First-principles calculation based on density functional theory with the generalized gradient approximation (GGA) were carried out to investigate the energy band gap structure of this special structure. The calculation results show that the indirect–direct band gap transition occurs when the nanonets are properly designed. This band gap transition is dominated by the passivation bonds, porosities as well as pore array distributions. It is also proved that Si–O–Si is an effective passivation bond which can change the band gap structure of the nanonets. These results provide another way to achieve a practical silicon-based light source

Quantitative Imaging of Gd Nanoparticles in Mice Using Benchtop Cone-Beam X-ray Fluorescence Computed Tomography System

Nanoparticles (NPs) are currently under intensive research for their application in tumor diagnosis and therapy. X-ray fluorescence computed tomography (XFCT) is considered a promising non-invasive imaging technique to obtain the bio-distribution of nanoparticles which include high-Z elements (e.g., gadolinium (Gd) or gold (Au)). In the present work, a set of experiments with quantitative imaging of GdNPs in mice were performed using our benchtop XFCT device. GdNPs solution which consists of 20 mg/mL NaGdF4 was injected into a nude mouse and two tumor-bearing mice. Each mouse was then irradiated by a cone-beam X-ray source produced by a conventional X-ray tube and a linear-array photon counting detector with a single pinhole collimator was placed on one side of the beamline to record the intensity and spatial information of the X-ray fluorescent photons. The maximum likelihood iterative algorithm with scatter correction and attenuation correction method was applied for quantitative reconstruction of the XFCT images. The results show that the distribution of GdNPs in each target slice (containing liver, kidney or tumor) was well reconstructed and the concentration of GdNPs deposited in each organ was quantitatively estimated, which indicates that this benchtop XFCT system provides convenient tools for obtaining accurate concentration distribution of NPs injected into animals and has potential for imaging of nanoparticles in vivo

Preparation Process of Straw-based Activated Carbon for Uranium Wastewater Treatment

A process and equipment for preparing activated carbon from straw and its application in treating uranium wastewater are proposed. The ZnCl2-microwave carbonization method is adopted, which flexibly applies the wave absorbing ability of zinc element and greatly reduces the carbonization time. At the same time, the dehydrogenation of ZnCl2 limits the formation of coal tar and improves the carbon formation rate. Through citric acid modification, a functional group with specific adsorbability to uranyl ions is formed, which can produce high-efficiency complexation effect with uranyl ions and improve the adsorption capacity of uranyl ions. When the wastewater is mixed with other heavy metal elements, uranyl ions occupy the main adsorption sites, which can still maintain excellent targeted adsorption effect and can be targeted to treat uranyl ions in radioactive uranium wastewater. The key equipment in the process consists of cleaning and impurity removal components, raw material crushing components and carbonization components. The whole production process is completed in the same equipment. The optimum adsorption capacity (Ac) of 4.98 mg/g and uranium adsorption rate (Ar) of 99% were obtained by using soybean straw as raw material under the preparation conditions of 20% ZnCl2 solution and 15% citric acid solution

Genetic evidence of tri-genealogy hypothesis on the origin of ethnic minorities in Yunnan

Abstract Background Yunnan is located in Southwest China and consists of great cultural, linguistic, and genetic diversity. However, the genomic diversity of ethnic minorities in Yunnan is largely under-investigated. To gain insights into population history and local adaptation of Yunnan minorities, we analyzed 242 whole-exome sequencing data with high coverage (~ 100–150 ×) of Yunnan minorities representing Achang, Jingpo, Dai, and Deang, who were linguistically assumed to be derived from three ancient lineages (the tri-genealogy hypothesis), i.e., Di-Qiang, Bai-Yue, and Bai-Pu. Results Yunnan minorities show considerable genetic differences. Di-Qiang populations likely migrated from the Tibetan area about 6700 years ago. Genetic divergence between Bai-Yue and Di-Qiang was estimated to be 7000 years, and that between Bai-Yue and Bai-Pu was estimated to be 5500 years. Bai-Pu is relatively isolated, but gene flow from surrounding Di-Qiang and Bai-Yue populations was also found. Furthermore, we identified genetic variants that are differentiated within Yunnan minorities possibly due to the living circumstances and habits. Notably, we found that adaptive variants related to malaria and glucose metabolism suggest the adaptation to thalassemia and G6PD deficiency resulting from malaria resistance in the Dai population. Conclusions We provided genetic evidence of the tri-genealogy hypothesis as well as new insights into the genetic history and local adaptation of the Yunnan minorities

Numerical study on the performance of a two-nozzle spray cooling system under different conditions

The cooling performance of natural draft dry cooling towers (NDDCTs) would significantly be reduced when the ambient air is hot. To address this problem, the spray pre-cooling technology has been introduced to cool the inlet air of the tower. The effect of two-nozzle distance on the evaporative cooling performance will instruct the arrangement of multi-nozzle for industrial applications. This paper is therefore to study two nozzles vertically arranged in a wind tunnel by the numerical simulation. A 3-D model was developed and validated for simulation studies. The effects of two-nozzle distance, inlet air speed, inlet air dry-bulb temperature and humidity on the evaporative cooling performance were investigated. Besides, a modified cooling efficiency was proposed to effectively evaluate the cooling performance with considering both the cooling affected region and the air temperature drop. The simulation results indicate that the modified cooling efficiency is more or less affected by the two cooling affected regions generated by two nozzles at the wind tunnel exit. The modified cooling efficiency of the tangent region is similar to that of the separating region, and it is 2.5% higher than the partially overlapping region. Generally, the high modified cooling efficiency is accompanied with the high air dry-bulb temperature and the low humidity. The modified cooling efficiency increases with the decreasing inlet air speed

Irisin attenuates myocardial ischemia/reperfusion‐induced cardiac dysfunction by regulating ER‐mitochondria interaction through a mitochondrial ubiquitin ligase‐dependent mechanism

Abstract Background Myocardial ischemia/reperfusion (MI/R) injury imposes devastating cardiovascular sequelae in particular cardiac dysfunction as a result of restored blood flow. However, the mechanism behind MI/R injury remains elusive. Mitochondrial ubiquitin ligase (MITOL/MARCH5) is localized at the mitochondria‐ER contact site and may be activated in response to a variety of pathophysiological processes, such as apoptosis, mitochondrial injury, ER stress, hypoxia, and reactive oxygen species (ROS) generation. Irisin as a cleaved product of fibronectin type III domain‐containing protein 5 (FNDC5) displays cardioprotection in diverse cardiac diseases. Methods This study was designed to examine the role of irisin and MITOL in MI/R injury. Male C57BL/6J mice (8‐10‐week‐old) were administered adenovirus MITOL shRNA through intracardiac injection followed by MI/R surgery through ligation and release the slipknot of cardiac left anterior descending coronary artery. Results Our results showed that irisin improved myocardial function in the face of MI/R injury as evidenced by reduced myocardial infarct size, apoptotic rate, serum lactate dehydrogenase (LDH), ROS generation, and malondialdehyde (MDA) levels as well as lessened ER stress injury. Moreover, our results indicated that protective role of irisin was mediated by upregulation of MITOL. Irisin also protected H9c2 cells against simulated I/R through negating ER stress, apoptosis, ROS and MDA levels, as well as facilitating superoxide dismutase (SOD) by way of elevated MITOL expression. Conclusions To this end, our data favored that irisin pretreatment protects against MI/R injury, ER stress, ROS production, and mitochondrial homeostasis through upregulation of MITOL. These findings depicted the therapeutic potential of irisin and MITOL in the management of MI/R injury in patients with ST‐segment elevation

Distribution of Two HIV-1–Resistant Polymorphisms (SDF1-30A and CCR2-64I) in East Asian and World Populations and Its Implication in AIDS Epidemiology

Chemokine receptor CCR2 and stromal-derived factor (SDF-1) are involved in HIV infection and AIDS symptom onset. Recent cohort studies showed that point mutations in these two genes, CCR2-64I and SDF1-3′A, can delay AIDS onset ⩾16 years after seroconversions. The protective effect of CCR2-64I is dominant, whereas that of SDF1-3′A is recessive. SDF1-3′A homozygotes also showed possible protection against HIV-1 infection. In this study, we surveyed the frequency distributions of the two alleles at both loci in world populations, with emphasis on those in east Asia. The CCR2-64I frequencies do not vary significantly in the different continents, having a range of 0.1–0.2 in most populations. A decreasing cline of the CCR2-64I frequency from north to south was observed in east Asia. In contrast, the distribution of SDF1-3′A in world populations varies substantially, and the highest frequency was observed in Oceanian populations. Moreover, an increasing cline of the SDF1-3′A frequency from north to south was observed in east Asia. The relative hazard values were computed to evaluate the risk of AIDS onset on the basis of two-locus genotypes in the east Asian and world populations