18 research outputs found
Acceleration compensation of a novel piezoelectric balance for the short duration impulse measurement: a time series analysis approach
A novel piezoelectric balance was developed to measure the six-component forces for the complex aircraft scaled model in the impulse combustion wind tunnel at a short duration airloads Mach number of 5. The piezoelectric balance using four triaxial piezoelectric load cells yields the high stiffness, sensitive and good dynamic response characteristics. The dynamic model-balance system was built to analyze the vibration characteristic. The time series analysis approach was developed on the basis of the system transfer function and the natural frequency, and the accelerated forces which induce the airloads overshooting oscillations had been obtained by the second order derivatives function. The experimental results have shown that the problem of overshooting oscillations effect of the impulse can be effectively solved by the acceleration compensation technology for the complex test model with the novel piezoelectric balance
Macrophage inhibits the osteogenesis of fibroblasts in ultrahigh molecular weight polyethylene (UHMWPE) wear particle-induced osteolysis
Background
In the ultrahigh molecular weight polyethylene (UHMWPE) prosthetic environment, fibroblasts affected by wear particles have the capacity of osteogenesis to reduce osteolysis. We aimed to assess the effects of macrophages on the osteogenic capability of fibroblasts treated with UHMWPE wear particles.
Methods
The effect of different concentrations of UHMWPE (0, 0.01, 0.1, and 1 mg/ml, respectively) on macrophage proliferation were validated by MTT assay to determine the optimum one. The fibroblasts viability was further determined in the co-culture system of UHMWPE particles and macrophage supernatants. The experiment was designed as seven groups: (A) fibroblasts only; (B) fibroblasts + 1 mg/ml UHMWPE particles; and (C1–C5) fibroblasts + 1/16, 1/8, 1/4, 1/2, and 1/1 supernatants of macrophage cultures stimulated by 1 mg/ml UHMWPE particles vs. fibroblast complete media, respectively. Alizarin red staining was used to detect calcium accumulation. The expression levels of osteogenic proteins were detected by Western blot and ELISA, including alkaline phosphatase (ALP) and osteocalcin (OCN).
Results
The concentration of 0.1 mg/ml was considered as the optimum concentration for macrophage proliferation due to the survival rate and was highest among the four concentrations. Fibroblast viability was better in the group of fibroblasts + 1/16 ratio of macrophage supernatants stimulated by 1 mg/ml of UHMWPE particles than the other groups (1:8, 1:4, 1:2, 1:1). ALP and OCN expressions were significantly decreased in the group of fibroblasts + 1/4, 1/2, and 1/1 supernatants stimulated by 1 mg/ml of UHMWPE particles compared with other groups (1/8, 1/16) and the group of fibroblasts + 1 mg/ml UHMWPE (p < 0.5).
Conclusions
Macrophages are potentially involved in the periprosthetic osteolysis by reducing the osteogenic capability of fibroblasts treated with wear particles generated from UHMWPE materials in total hip arthroplasty.China Sholarship Council (Grant 201506370173)China. National Natural Science Foundation (Grant 31200739)China. National Natural Science Foundation (Grant 31470948
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GWAS Identifies Novel Susceptibility Loci on 6p21.32 and 21q21.3 for Hepatocellular Carcinoma in Chronic Hepatitis B Virus Carriers
Genome-wide association studies (GWAS) have recently identified KIF1B as susceptibility locus for hepatitis B virus (HBV)–related hepatocellular carcinoma (HCC). To further identify novel susceptibility loci associated with HBV–related HCC and replicate the previously reported association, we performed a large three-stage GWAS in the Han Chinese population. 523,663 autosomal SNPs in 1,538 HBV–positive HCC patients and 1,465 chronic HBV carriers were genotyped for the discovery stage. Top candidate SNPs were genotyped in the initial validation samples of 2,112 HBV–positive HCC cases and 2,208 HBV carriers and then in the second validation samples of 1,021 cases and 1,491 HBV carriers. We discovered two novel associations at rs9272105 (HLA-DQA1/DRB1) on 6p21.32 (OR = 1.30, P = 1.13×) and rs455804 (GRIK1) on 21q21.3 (OR = 0.84, P = 1.86×), which were further replicated in the fourth independent sample of 1,298 cases and 1,026 controls (rs9272105: OR = 1.25, P = 1.71×; rs455804: OR = 0.84, P = 6.92×). We also revealed the associations of HLA-DRB1*0405 and 0901*0602, which could partially account for the association at rs9272105. The association at rs455804 implicates GRIK1 as a novel susceptibility gene for HBV–related HCC, suggesting the involvement of glutamate signaling in the development of HBV–related HCC
A Metal Ion and Thermal-Responsive Bilayer Hydrogel Actuator Achieved by the Asymmetric Osmotic Flow of Water between Two Layers under Stimuli
Shape-morphing hydrogels have drawn great attention due to their wide applications as soft actuators, while asymmetric responsive shape-morphing behavior upon encountering external stimuli is fundamental for the development of hydrogel actuators. Therefore, in this work, bilayer hydrogels were prepared and the shrinkage ratios (LA/LN) of the AAm/AAc layer to the NIPAM layer immersed in different metal ion solutions, leading to bending in different directions, were investigated. The difference in the shrinkage ratio was attributed to the synergistic effect of the osmolarity difference between the inside and outside of the hydrogels and the interaction difference between the ion and hydrogel polymer chains. Additionally, under thermal stimuli, the hydrogel actuator would bend toward the NIPAM layer due to the shrinkage of the hydrogel networks caused by the hydrophilic–hydrophobic phase transition of NIPAM blocks above the LCST. This indicates that metal ion and thermal-responsive shape-morphing hydrogel actuators with good mechanical properties could be used as metal ion or temperature-controllable switches or other smart devices
Reliability Evaluation of Smart Substation Based on Time-Varying Probabilistic Hybrid Attack Graph
A substation is the portion of a power grid that forms a link between the cyber system and the physical system. Reliability evaluation of smart substations based on a time-varying probabilistic hybrid attack graph (TVPHAG) is studied in this paper. First, the topology network of the smart substation is established, whose attributes are represented by probability. Then, in order to solve the problem of asynchrony in the cyber-physical system and the hybrid caused by heterogeneity, time-varying state equation in topology and cuts in algebra are introduced to TVPHAG. Based on TVPHAG, the evaluation of the reliability of cyber-physical systems with multiple equipment and multiple timescales is established. On this basis, the influences of physical conditions, cyberattacks, physical attacks, and cyber-physical attacks on substations are analyzed, respectively. Finally, the simulation shows that the method is effective in evaluating the reliability of smart substations, providing a new method for the evaluation of reliability
Energy Efficient Deployment of a Service Function Chain for Sustainable Cloud Applications
With the increasing popularity of the Internet, user requests for cloud applications have dramatically increased. The traditional model of relying on dedicated hardware to implement cloud applications has not kept pace with the rapid growth in demand. Network function virtualization (NFV) architecture emerged at a historic moment. By moving the implementation of functions to software, a separation of functions and hardware was achieved. Therefore, when user demand increases, cloud application providers only need to update the software; the underlying hardware does not change, which can improve network scalability. Although NFV solves the problem of network expansion, deploying service function chains into the underlying network to optimize indicators remains an important research problem that requires consideration of delay, reliability, and power consumption. In this paper, we consider the optimization of power consumption with the premise of guaranteeing a certain virtual function link yield. We propose an efficient algorithm that is based on first-fit and greedy algorithms to solve the problem. The simulation results show that the proposed algorithm substantially improves the path-finding efficiency, achieves a higher request acceptance ratio and reduces power consumption while provisioning the cloud applications. Compared with the baseline algorithm, the service function chain (SFC) acceptance ratio of our proposed algorithms improves by a maximum of approximately 15%, our proposed algorithm reduces the power consumption by a maximum of approximately 15%, the average link load ratio of our proposed algorithm reduces by a maximum of approximately 20%, and the average mapped path length of our proposed algorithm reduces by a maximum of approximately 1.5 hops
Evaluation and characterization of volatile air toxics indoors in a heavy polluted city of northwestern China in wintertime
Hazardous volatile organic compounds (VOCs) and carbonyls were evaluated in typical dwellings in Xi'an in northwestern China in wintertime. High indoor concentrations were observed for formaldehyde, acetone, naphthalene, methylene chloride and acetaldehyde, associated with characteristic pollution sources. In comparison, many of the target VOCs were higher in Chinese dwellings than those in other countries, suggesting the significances of indoor pollutions in China. Source apportionment with receptor model shows that furniture and building materials (44.5%), paints and adhesives (11.9%), household products (17.3%), smoking (14.5%), and cooking (9.8%) are the major contributors to the indoor VOCs and carbonyls. The health risk assessment shows that the cancer risks for formaldehyde (5.73 x 10(-5)), 1,3-butadiene (2.07 x 10(-5)) and 1,2-dichloroethane (1.44 x 10(-5)) were much higher than the acceptable level of 1 x 10(-6) recommended by International Register for Certified Auditors (IRCA). The hazard quotient (HQ) of target VOCs were far less than the threshold (HQ = 1). Moreover, the practical efficiency of household air purifier in removal of the VOCs and carbonyls was examined first time in dwellings in northern China. The results prove that most of the indoor organic pollutants and their cancer risk to humans can be efficiently reduced, particularly for formaldehyde and 1,3-butadiene. The findings of the study offer useful preliminary and updated information on current indoor air toxics levels, dominant pollution sources and their potential health risks to residents in northwest China. (C) 2019 Elsevier B.V. All rights reserved
Manganese Slag Amendment Reduces Greenhouse Gas Emissions from Paddy Soil
Increasing crop productivity and minimizing greenhouse gas emissions from paddy fields are increasingly receiving attention. Slag application not only can maximize the use of solid wastes as beneficial resources for agricultural production, but it also reduces greenhouse gas emissions. In order to determine the most effective slags as soil amendments for greenhouse gas emission reduction, three major slags, i.e., steel, titanium and manganese slags, were applied as soil amendments to paddy soils; correspondingly, the greenhouse gas emissions, cumulative emissions and global warming potential of the soils during one growing season were measured. It was found that applying all these three slags could reduce the methane emission rates and the cumulative methane emissions. Manganese slag significantly decreased methane emissions by 55% compared with the control. Carbon dioxide caused no significant changes among different slag treatments; however, the cumulative carbon dioxide emissions from fields treated with steel and manganese slags were lower than those from control fields. The global warming potential of paddy soil with manganese application was 63% lower than that of the control. Finally, manganese oxide was found to have a negative relation with greenhouse gas emissions. It was inferred that the electron acceptors and the photocatalysis of manganese oxide minerals might have been the main reasons for greenhouse gas reduction. This preliminary result could be further applied to utilizing solid wastes as beneficial resources and to developing carbon fixation and greenhouse gas reduction fertilizers
Associations of fruit, whole grain, and total energy intakes with gut microbiome diversity and composition
Background: The relationship between fruit, whole grain, and total energy consumption and the gut microbiome in the Chinese population remains unclear. Objective: We investigated the relationship between intakes of fruits, whole grains, and energy, and the diversity and composition of gut microbiota. Design: This cross-sectional study included 167 subjects aged 40-75 years who underwent colonoscopy at Nankai Hospital in Tianjin, China. Each of the participants completed a personal history questionnaire, a 7-day dietary record, and donated a fecal sample. The V3-V4 hypervariable region of the bacterial 16S rRNAgene was amplified and sequenced using Illumina Novaseq. The relationship between diet and gut microbiota was evaluated in terms of both the overall composition and the abundance of specific taxon. Results: Fruits intake was positively related to the abundance of Bacilli, Porphyromonadaceae, Streptococcaceae, Parabacteroides, Streptococcus, and Bilophila in fecal samples. Higher whole grains intake was associated with higher microbial diversity, as measured by Shannon, Simpson, and Chao1 indices. Specifically, there was a significant increase inthe relative abundance of Lachnospiraceae and a decrease in Actinobacteria with increased whole grains intake. Moreover, higher intake of total energy was associated with a lower abundance of Anaerostipes and a higher abundance of Lactobacillales and Acidaminococcus. Conclusion: Whole grains intake was positively associated with gut microbial diversity. Fruits and total energy intake were related to the abundance of specifictaxon (e.g., Bacilli and Acidaminococcus). These findings highlight the potential importance of dietary interventions for modulating gut microbiota composition and promoting overall health
Evaluation and characterization of volatile air toxics indoors in a heavy polluted city of northwestern China in wintertime
Hazardous volatile organic compounds (VOCs) and carbonyls were evaluated in typical dwellings in Xi'an in northwestern China in wintertime. High indoor concentrations were observed for formaldehyde, acetone, naphthalene, methylene chloride and acetaldehyde, associated with characteristic pollution sources. In comparison, many of the target VOCs were higher in Chinese dwellings than those in other countries, suggesting the significances of indoor pollutions in China. Source apportionment with receptor model shows that furniture and building materials (44.5%), paints and adhesives (11.9%), household products (17.3%), smoking (14.5%), and cooking (9.8%) are the major contributors to the indoor VOCs and carbonyls. The health risk assessment shows that the cancer risks for formaldehyde (5.73 x 10(-5)), 1,3-butadiene (2.07 x 10(-5)) and 1,2-dichloroethane (1.44 x 10(-5)) were much higher than the acceptable level of 1 x 10(-6) recommended by International Register for Certified Auditors (IRCA). The hazard quotient (HQ) of target VOCs were far less than the threshold (HQ = 1). Moreover, the practical efficiency of household air purifier in removal of the VOCs and carbonyls was examined first time in dwellings in northern China. The results prove that most of the indoor organic pollutants and their cancer risk to humans can be efficiently reduced, particularly for formaldehyde and 1,3-butadiene. The findings of the study offer useful preliminary and updated information on current indoor air toxics levels, dominant pollution sources and their potential health risks to residents in northwest China