Piperonyl butoxide synergizes the larvicidal activity of Origanum vulgare essential oil and its major constituents against the larvae of Aedes albopictus and Culex pipiens quinquefasciatus

Chen Junhui,Liu Yangqing,Ma Guangqiang,Yang Feiying,Zhan Zhigao,Guan Limei,Kuang Wendong,Wang Jinchang,Li Jianghuai,Han Fei,Jin Liang 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.1

Mosquitoes bite human beings and transmit many diseases, such as malaria, dengue fever, and Zika virus. Vector control of mosquitoes is an effective strategy for reducing the spread of disease. However, extensive use of in secticides (e.g. pyrethroids and organophosphorus) has caused resistance in mosquitoes, which weakens the effectiveness of mosquito control. Phytochemicals have been considered an alternative approach to mosquito control. Essential oil (EO) was obtained from the leaves and flowers of Origanum vulgare, and its synergistic activity with piperonyl butoxide (PBO) was tested against Aedes albopictus and Culex pipiens quinquefasciatus larvae. Thirty-seven compounds were identified, among which carvacrol and thymol were two major constitu ents (30.73 % and 18.81 %, respectively). O. vulgare EO had a significant toxic effect against fourth-stage larvae of Cx. p. quinquefasciatus and Ae. albopictus, with LC 50 values of 17.51 and 75.90 mg/L. Carvacrol and thymol also each appeared to be more effective against Cx. p. quinquefasciatus (LC 50 = 19.30 and 11.56 mg/L, respectively) than Ae. albopictus (LC 50 = 26.62 and 26.66 mg/L, respectively). PBO interacted synergistically with O. vulgare EO, carvacrol and thymol with 2.60–6.26 times as much of the active compound needed without PBO as against Cx. p. quinquefasciatus and Ae. albopictus larvae. Overall, our results contribute to the development of new natural mosquito insecticides.

Gut-derived lipopolysaccharide promotes alcoholic hepatosteatosis and subsequent hepatocellular carcinoma by stimulating neutrophil extracellular traps through toll-like receptor 4

Yang Liu,Xin Zhang,Shuo Chen,Jiazhong Wang,Shuo Yu,Yiming Li,Meng Xu,Harouna Aboubacar,Junhui Li,Tao Shan,Jixin Wang,Gang Cao 대한간학회 2022 Clinical and Molecular Hepatology(대한간학회지) Vol.28 No.3

Background/Aims: Binge drinking leads to many disorders, including alcoholic hepatosteatosis, which is characterized by intrahepatic neutrophil infiltration and increases the risk of hepatocellular carcinoma (HCC). Molecular mechanisms may involve the migration of bacterial metabolites from the gut to the liver and the activation of neutrophil extracellular traps (NETs). Methods: Serum samples from both binge drinking and alcohol-avoiding patients were analyzed. Mouse models of chronic plus binge alcohol-induced hepatosteatosis and HCC models were used. Results: A marker of NETs formation, lipopolysaccharide (LPS), was significantly higher in alcoholic hepatosteatosis and HCC patients and mice than in controls. Intrahepatic inflammation markers and HCC-related cytokines were decreased in mice with reduced NET formation due to neutrophil elastase (NE) deletion, and liver-related symptoms of alcohol were also alleviated in NE knockout mice. Removal of intestinal bacteria with antibiotics led to decreases in markers of NETs formation and inflammatory cytokines upon chronic alcohol consumption, and development of alcoholic hepatosteatosis and HCC was also attenuated. These functions were restored upon supplementation with the bacterial product LPS. When mice lacking toll-like receptor 4 (TLR4) received chronic alcohol feeding, intrahepatic markers of NETs formation decreased, and hepatosteatosis and HCC were alleviated. Conclusions: Formation of NETs following LPS stimulation of TLR4 upon chronic alcohol use leads to increased alcoholic steatosis and subsequent HCC.

Application of Teaching Data Mining Based on Cloud Computing in the Prediction of Learning Achievement

Jianfen Liu,Junhui Zheng 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.6

Under the highly development of the information society, only by carrying out education reform can be cultivate more innovative talents. Because the traditional education idea has already taken root in the hearts of people, education informatization is a necessary way to change this kind of thought. The generation of cloud computing technology leads to the revolution of data processing technology. It can make use of a small amount of resources to effectively deal with the big data in the information system of educational institutions. Neural network is one of the important technologies of educational data mining in cloud computing environment. BP neural network is a typical multi-layer forward network, which is composed of input layer, hidden layer and output layer. It can be used to predict the data through the training model. In this paper, based on the characteristics of the distribution of education resources, we put forward the method to analyze big data of education by using Hadoop technology. This method uses the MapReduce programming model to manage the data, so as to improve the speed and efficiency of data analysis. Secondly, in Hadoop platform, this paper puts forward the method of parallel BP neural network in education data processing. The method consists of the following main steps: firstly, input data and set up a three layer parallel neural network. Secondly, according to the location of each node to block the data, and transfer M separate blocks to the Map function for processing. Thirdly, through the gradient descent method, the Map function finds the weight distribution of each block by iterative algorithm. Fourthly, we transfer the key-vlaue to the Reduce function, and update the statistics. Finally, repeat the update the calculation process of weight. After several iterations, the optimal solution of the objective function is found, and the weight distribution of the network is obtained. Finally, we simulate the parallel BP neural network algorithm based on education cloud platform, in order to prove that it is suitable for the prediction of learning achievement of the network teaching system.

An Iterative Computing Method for Load Effect of Bidirectional Reinforced Embankment

Weizheng Liu,Kang Sun,Weihua Lu,Junhui Zhang,Yongxing Zhang,Bo Yang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.5

Bidirectional reinforced embankment (BRE) technology, pile supporting in vertical and geosynthetic reinforcement in horizontal, has been widely adopted in engineering practice to control total and/or differential settlement. In design, the load distribution of BRE is essential for determining pile size (i.e., diameter and length), pile spacing, pile cap details (if any), and properties of geosynthetic reinforcement, et al. Several methods have been proposed in previous studies to investigate the load bearing mechanism in the BRE platform. However, resistance of foundation soil is typically neglected, which implies that the load on piles would be overestimated if the resistance of foundation soil is neglected or over weakened. The reason for this overestimation is that larger geosynthetic deflection would be expected without the reaction of foundation soil, which would cause a more significant soil arching and thus more load would be transferred to piles. To minimize this overestimation, a method for analyzing load transfer mechanism in the BRE was proposed, considering the subsoil resistance as well as the existence of neutral plane (i.e., zero skin friction). An equal settlement was assumed for soils at the embankment bottom and the foundation top. The iteration process was adopted to solve equations to determine the load shared by piles and soils. In derivation, the soil arch height in the embankment was calculated instead of being assumed in existing methods. A flow chart was developed to solve equations of the proposed method and two case histories from literatures were used to compose the rationality verification. Compared with the field measurement and numerical calculation, this study can be more effective in calculating loads shared by piles and soils in the BRE for the working condition with better pile end bearing stratum.

Expression of Cdc25B mRNA in Duodenal Mucosa of Chicken

Qin, Junhui,Zhang, Hui,Bao, Huijun,Zhou, Qiang,Liu, Yi,Xu, Chunsheng,Chu, Xiaohong,Chen, Qiusheng Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.4

Cdc25B is a mitotic regulator that might act as a starter phosphatase to initiate the positive feedback loop at the entry into mitotic (M) phase. In the present study, distribution of Cdc25B mRNA in duodenal mucosa of the chicken was demonstrated by means of in situ hybridization histochemistry (ISHH) using sense and antisense digoxigenin (DIG)-labeled RNA probes. The results showed that there were many labeled cells distributing in the duodenal mucosa of the adult chicken. Of these labeled cells, 81.60${\pm}$9.63% of Cdc25B mRNA positive cells was distributed in the basilar part and mid-portion of the intestinal gland and 36.21${\pm}$8.81% in the middle and basilar portion of villi of the small intestine of the chicken, respectively. Most of these labeled cells were positive in the regions of the stem cell and proliferation. The signals of ISHH decreased from basilar to upper part in the crypt of Lieberkuhn and weakened in the inferior villi of the duodenum. Moreover, the positive signals were both in the cytoplasm and cell nucleus. However, the labeled cells were negative in both the lamina muscularis mucosae and muscular layer. The results of ISHH suggested the existence of Cdc25B mRNA and vigorous proliferation activities in the duodenal mucosa of adult chicken, replenishing the cells which had sloughed off from the superior part of the villus. Our results provide some molecular evidence for a regular pattern of avian intestinal epitheliosis and functional partition and provide an approach to further study of the locations of Cdc25B in the chicken.

The Expression Patterns of Cdc25A, Cdc25B, Sox2 and Mnb in Central Nervous System in Early Chicken Embryos

Zhang, Hui,Qin, Junhui,Cao, Jingjing,Hei, Nainan,Xu, Chunsheng,Yang, Ping,Liu, Haili,Chu, Xiaohong,Bao, Huijun,Chen, Qiusheng Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.6

The sense and antisense digoxigenin-labeled RNA probes of four genes, Cdc25A, Cdc25B, Sox2 and Mnb, were produced by using SP6 and T7 RNA polymerases, respectively, and in vitro transcription. Expression patterns of the four genes were detected by in situ hybridization in HH (Hamburger and Hamilton) stage 10 chick embryos. In general, expression patterns of the four genes were similar. mRNA of the four genes was mostly restricted to the entire CNS (central nervous system). All were confined to an identical region, neural tube, neural groove and caudal neural plate, corresponding to the notochord or spinal cord, but there was some distinction in specific region or in concentration, for example in somites. The overlap in expression at the same developmental stage in the CNS suggests that the four genes may be functional similar or related in CNS development. Expression patterns of the four genes support specific roles of these regulators in the developing CNS.

Mechanical Properties and VOC Emission of Hemp Fibre Reinforced Polypropylene Composites: Natural Freezingmechanical Treatment and Interface Modification

Zhigang Li,Xinpei Wei,Junhui Liu,Hongjiang Han,Hongjie Jia,Jiawang Song 한국섬유공학회 2021 Fibers and polymers Vol.22 No.4

In this study, the effects of natural freezing-mechanical treatment and interface modification on the mechanicalproperties and VOC emissions of hemp fibre-reinforced polypropylene composites were investigated. To evaluate theinfluence of natural freezing-mechanical treatment on fibres and composites, several tests were performed. Natural freezingmechanicaltreatment of HF enhanced the mechanical properties and reduced the VOC emissions of HF/PP compositescompared with untreated composites. After the degumming treatment, HF was treated with urea and KH-550, and themechanical properties of the modified composites were better than those of the unmodified composites. Compared with thetensile strength, flexural strength and impact strength of the unmodified composites, the mechanical properties of the ureamodifiedcomposites were enhanced by 16.45 %, 17.32 % and 13.23 %, respectively; the mechanical properties of thecomposites modified by the coupling agent KH-550 were increased by 19.53 %, 20.40 % and 11.19 %, respectively. The totalVOC emissions of modified HF/PP composites were lower than those of the unmodified composites. The obtained resultsdemonstrated that natural freezing-mechanical treatment is an effective fibre degumming method. Combined with interfacemodification, the composite has the characteristics of low VOC emissions, high strength, and good interface bonding.

Effect of Cu on Pore Structure of Al–Si Foam

Fan Deng,Jianzhong Fan,Yanqiang Liu,Xuehan Lu,Shaohua Wei,Junhui Nie 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

The alloy composition is an important factor effecting the pore structure of aluminum foam. In this paper, the powder compactfoaming method was used, and different content of Cu element powders were added to the alloy Al–9Si, for investigatingthe effect of alloying element on foaming process. With the Cu content of Al–Si–Cu alloy increasing, the expansion ratio isincreased, the time required to reach maximum expansion is shortened, and the number of fissure-like pores at early foamingstage is decreased. This improving action is related to the higher volume fraction of liquid phase in same melting temperaturecaused by increasing Cu content in alloy. Comparing different Al–Si–Cu alloys with different Cu content at same expansionratio, the higher Cu content, the smaller pore size and the thinner cell wall. This beneficial effect on pore structure is attributedto the addition of Cu that is benefit to increasing the viscosity of Al–Si–Cu alloy during foaming. And at same expansionrate, the more content of Cu in Al–Si–Cu alloy, the higher compressive strength of aluminum foam.

Numerical investigation on the dynamic behaviors of turbine valve disc–seat impact at low velocity

Jianfeng Mao,Wei Zhe Wang,Junhui Zhang,Ying Zheng Liu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2

In this study, the dynamic behaviors on a valve seat subjected to the impact of the valve disc at low velocities were investigated by usingnumerical analysis with finite element method. The impact damage of the valve disc against seat was evaluated through a threedimensionaldynamic explicit calculation. The parameters considered in the simulations were impact velocity, disc obliquity, aspect ratio,and contact area ratio. The model for impact calculation was implemented in the code ABAQUS, which is based on the constitutiveequation and fracture strain equation of Johnson and Cook, as well as on continuum damage mechanics. The distribution of damagecaused by the impact was computed and discussed. The impact damage of the valve disc was minimized when the disc obliquity wasapproximately 40°. The effects of variation of selected design parameters on dynamic behaviors were discussed. The best design parameterswere proposed, which served as a guide for future valve design.

Numerical investigation on life improvement of low-cycle fatigue for an ultra-supercritical steam turbine rotor

Nai-long Zhao,Wei Zhe Wang,Junhui Zhang,Ying Zheng Liu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

In this paper, an axisymmetric rotor of a 1000-MW ultra-supercritical steam turbine was modeled with the commercial finite-element software ABAQUS with inlet parameters of 35 Mpa and 600°C. The temperature and Mises stress distributions of the rotor during the start-up procedure were then analyzed. The fatigue damage was predicted by the strain-life–based Manson-Coffin equation and the Miner rule. The results demonstrated that the fatigue damage was mainly generated at the rotor surface. For the requirement of the half life time, the cyclic number almost reached 4000. Furthermore, optimization by extending the warm-up phase is proposed to eliminate strain fluctuations and further decrease fatigue damage. The results showed that the fatigue damage significantly decreased at four key locations. The fatigue life during the start-up phase was improved.