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Nodule Rich Protein 2 modulates nodule number in Medicago truncatula
Junhui Yan,Xinwei Yang,Yawen Wang,Liangliang Yu,Li Luo 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.1
Symbiotic nitrogen fxation is beneft to sustainable agriculture and global nitrogen cycle. Many small peptides were identifed as regulators involving in the interaction between rhizobia and legume. Here we reported Nodule Rich Protein 2 (MtNRP2) encoding a small peptide in Medicago truncatula, belonged to a group of nodule rich protein restricted in legume species. MtNRP2 expressed highly in root nodule and its promoter was active during the initiation and development of root nodule and lateral root. To investigate the function of MtNRP2 in nodulation, we generated MtNRP2-overexpression and MtNRP2- knockdown transgenic Medicago. MtNRP2-overexpression transgenic lines performed normal nodulation phenotype compared with vector control. However, in the MtNRP2-RNAi transgenic plants, the decrease of MtNRP2 expression lead to the increase of infection threads number (7 day post inoculation) and nodules number (3 week post inoculation); meanwhile, the expression of MtRGF3 and MtPUB1 was inhibited. These results suggested that MtNRP2 negatively regulated nodulation in Medicago truncatula.
Junhui Zhang,Qun Chao,Bing Xu,Min Pan,Yuan Chen,Qiannan Wang,Ying Li 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.7
When manufacturing axial piston pumps, mass difference of piston-slipper assembly is inevitable because of manufacturing precision limits. Small mass difference may not cause problems when the pump operates at low speeds, while it cannot be ignored at high speeds. One problem related to high speed is the cylinder block tilt resulting from the inertial effect of piston-slipper assembly. Recently, the speed of electro-hydrostatic actuator (EHA) pump in aircraft can reach more than 10,000 rpm. Therefore, mass difference of pistonslipper assembly should be taken into account in future EHA pump design. The main purpose of this paper is to investigate the effect of the mass difference of piston-slipper assembly on the cylinder block tilt in a high-speed EHA pump. A detailed set of relevant equations is developed to establish the relationship between the mass difference of piston-slipper assembly and cylinder block tilting moment. It is found that a tighter control over the mass difference of piston-slipper assembly should be guaranteed when it comes to high-speed EHA pumps.
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.
Study of thermoacoustic oscillations in half-open tubes for saturated superfluid helium
Xianjin Wang,Xiaofei Niu,Feng Bai,Junhui Zhang,Shuping Chen 한국초전도저온학회 2022 한국초전도저온공학회논문지 Vol.24 No.3
Thermoacoustic oscillations (TAOs) are spontaneous pressure oscillations frequently seen in hydrogen or helium cryogenicsystems. Half-open tubes connected to cryogenic fluid with a closed room temperature end have a high potential for oscillationgeneration. Thermoacoustic oscillations will result in significant pressure fluctuations and additional heat load, endangering thesecurity and stability of the cryogenic system. The goal of this paper is to investigate TAOs in superfluid helium using boththeoretical and experimental methods. Five half-open tubes with varied typical inner diameters inserted into superfluid helium wereinstalled in a test cryostat. The onset characteristics of thermoacoustic oscillations were presented and studied. The effect oftemperature profile was discussed. Finally, a simple eliminating method was introduced.
Li Yunsen,Wang Junhui,Luo Liang 서울대학교 교육연구소 2020 Asia Pacific Education Review Vol.21 No.3
This study examines the effects of family migration on migrant children’s educational outcomes. We especially focus on the relative importance of family investment and school quality to children’s achievements. A unique and nationally representative sample from the National Children’s Study of China (NCSC) (2004 migrant children and 3923 rural children) is used. Estimates from the propensity score matching method suggest that conditional on basic personal and family characteristics, children’s academic performances are significantly improved by family migration. Further examination using the Oaxaca– Blinder decomposition approach reveals that over 40% of the differences in the children’s scores in Chinese and about 40% of those in mathematics can be explained by family investments (about 18.67–21.75% in different cases) and school quality (about 18–34.67% in different cases), including parental expectations, family material support, school expenditure, teacher quality, and student–teacher ratio. However, our results also reveal the potential for migrant children to be exposed to social exclusions in urban public schools.
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.
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.
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.