Alpha-Hemolysin from Staphylococcus aureus Obstructs Yeast-Hyphae Switching and Diminishes Pathogenicity in Candida albicans

Yu Xiaoyu,Mao Yinhe,Li Guangbo,Wu Xianwei,Xuan Qiankun,Yang Simin,Chen Xiaoqing,Cao Qi,Guo Jian,Guo Jinhu,Wu Wenjuan 한국미생물학회 2023 The journal of microbiology Vol.61 No.2

The use of antibiotics can disrupt the body’s natural balance and increase the susteptibility of patients towards fungal infections. Candida albicans is a dimorphic opportunistic fungal pathogen with niches similar to those of bacteria. Our aim was to study the interaction between this pathogen and bacteria to facilitate the control of C. albicans infection. Alpha-hemolysin (Hla), a protein secreted from Staphylococcus aureus, causes cell wall damage and impedes the yeast–hyphae transition in C. albicans. Mechanistically, Hla stimulation triggered the formation of reactive oxygen species that damaged the cell wall and mitochondria of C. albicans. The cell cycle was arrested in the G0/G1 phase, CDC42 was downregulated, and Ywp1 was upregulated, disrupting yeast hyphae switching. Subsequently, hyphae development was inhibited. In mouse models, C. albicans pretreated with Hla reduced the C. albicans burden in skin and vaginal mucosal infections, suggesting that S. aureus Hla can inhibit hyphal development and reduce the pathogenicity of candidiasis in vivo.

The Nedd8‐activating enzyme inhibitor MLN 4924 ( TAK ‐924/Pevonedistat) induces apoptosis via c‐Myc‐Noxa axis in head and neck squamous cell carcinoma

Zhang, Wenjuan,Liang, Yupei,Li, Lihui,Wang, Xiaofang,Yan, Zi,Dong, Changsheng,Zeng, Mu‐,Sheng,Zhong, Qian,Liu, Xue‐,Kui,Yu, Jinha,Sun, Shuyang,Liu, Xiaojun,Kang, Jihui,Zhao, Hu,Jeong, Lak BLACKWELL SCIENTIFIC PUBLICATIONS 2019 CELL PROLIFERATION Vol.52 No.2

The inertial coefficient for fluctuating flow through a dominant opening in a building

Xu, Haiwei,Yu, Shice,Lou, Wenjuan Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.18 No.1

For a building with a dominant windward wall opening, the wind-induced internal pressure response can be described by a second-order non-linear differential equation. However, there are two ill-defined parameters in the governing equation: the inertial coefficient $C_I$ and the loss coefficient $C_L$. Lack of knowledge of these two parameters restricts the practical use of the governing equation. This study was primarily focused on finding an accurate reference value for $C_I$, and the paper presents a systematic investigation of the factors influencing the inertial coefficient for a wind-tunnel model building including: opening configuration and location, wind speed and direction, approaching flow turbulence, the model material, and the installation method. A numerical model was used to simulate the volume deformation under internal pressure, and to predict the bulk modulus of an experimental model. In considering the structural flexibility, an alternative approach was proposed to ensure accurate internal volume distortions, so that similarity of internal pressure responses between model-scale and full-scale building was maintained. The research showed 0.8 to be a reasonable standard value for the inertial coefficient.

The loss coefficient for fluctuating flow through a dominant opening in a building

Xu, Haiwei,Yu, Shice,Lou, Wenjuan Techno-Press 2017 Wind and Structures, An International Journal (WAS Vol.24 No.1

Wind-induced fluctuating internal pressures in a building with a dominant opening can be described by a second-order non-linear differential equation. However, the accuracy and efficiency of the governing equation in predicting internal pressure fluctuations depend upon two ill-defined parameters: inertial coefficient $C_I$ and loss coefficient $C_L$, since $C_I$ determines the un-damped oscillation frequency of an air slug at the opening, while $C_L$ controls the decay ratio of the fluctuating internal pressure. This study particularly focused on the value of loss coefficient and its influence factors including: opening configuration and location, internal volumes, as well as wind speed and approaching flow turbulence. A simplified formula was presented to predict loss coefficient, therefore an approximate relationship between the standard deviation of internal and external pressures can be estimated using Vickery's approach. The study shows that the loss coefficient governs the peak response of the internal pressure spectrum which, in turn, will directly influence the standard deviation of the fluctuating internal pressure. The approaching flow characteristic and opening location have a remarkable effect on the parameter $C_L$.

Optimum Air-Gap Flux Distribution with Third Harmonic Rotor Flux Orientation Adjustment for Five-Phase Induction Motor

Min Kang,Wenjuan Yu,Zhengyu Wang,Wubin Kong,Ye Xiao 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

This paper investigates optimum air-gap flux distribution with third harmonic rotor flux orientation adjustment for five-phase induction motor. The technique of objective is to generate a nearly rectangular air-gap flux, and it improves iron utilization under variation loading conditions. The proportional relations between third harmonic and fundamental plane currents is usually adopted in the conventional method. However, misalignment between fundamental and third harmonic component occurs with variation loading. The iron of stator teeth is saturated due to this misalignment. This problem is solved by third harmonic rotor flux orientation adjustment simultaneously, and direction and amplitude are changed with mechanical load variation. The proposed method ensures that the airgap flux density is near rectangular for a maximum value from no load to rated load. It is confirmed that the proposed method guarantees complete both planes decoupling with third harmonic flux orientation adjustment. The effectiveness of the proposed technique is validated experimentally.

Optimum Air-Gap Flux Distribution with Third Harmonic Rotor Flux Orientation Adjustment for Five-Phase Induction Motor

Kang, Min,Yu, Wenjuan,Wang, Zhengyu,Kong, Wubin,Xiao, Ye The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

This paper investigates optimum air-gap flux distribution with third harmonic rotor flux orientation adjustment for five-phase induction motor. The technique of objective is to generate a nearly rectangular air-gap flux, and it improves iron utilization under variation loading conditions. The proportional relations between third harmonic and fundamental plane currents is usually adopted in the conventional method. However, misalignment between fundamental and third harmonic component occurs with variation loading. The iron of stator teeth is saturated due to this misalignment. This problem is solved by third harmonic rotor flux orientation adjustment simultaneously, and direction and amplitude are changed with mechanical load variation. The proposed method ensures that the air-gap flux density is near rectangular for a maximum value from no load to rated load. It is confirmed that the proposed method guarantees complete both planes decoupling with third harmonic flux orientation adjustment. The effectiveness of the proposed technique is validated experimentally.

The inertial coefficient for fluctuating flow through a dominant opening in a building

Haiwei Xu,Shice Yu,Wenjuan Lou 한국풍공학회 2014 한국풍공학회지 Vol.18 No.1

For a building with a dominant windward wall opening, the wind-induced internal pressureresponse can be described by a second-order non-linear differential equation. However, there are twoill-defined parameters in the governing equation: the inertial coefficient CI and the loss coefficient CL. Lack of knowledge of these two parameters restricts the practical use of the governing equation. This studywas primarily focused on finding an accurate reference value for CI, and the paper presents a systematicinvestigation of the factors influencing the inertial coefficient for a wind-tunnel model building including:opening configuration and location, wind speed and direction, approaching flow turbulence, the modelmaterial, and the installation method. A numerical model was used to simulate the volume deformationunder internal pressure, and to predict the bulk modulus of an experimental model. In considering thestructural flexibility, an alternative approach was proposed to ensure accurate internal volume distortions, sothat similarity of internal pressure responses between model-scale and full-scale building was maintained. The research showed 0.8 to be a reasonable standard value for the inertial coefficient.

The loss coefficient for fluctuating flow through a dominant opening in a building

Haiwei Xu,Shice Yu,Wenjuan Lou 한국풍공학회 2017 Wind and Structures, An International Journal (WAS Vol.24 No.1

Wind-induced fluctuating internal pressures in a building with a dominant opening can be described by a second-order non-linear differential equation. However, the accuracy and efficiency of the governing equation in predicting internal pressure fluctuations depend upon two ill-defined parameters: inertial coefficient CI and loss coefficient CL, since CI determines the un-damped oscillation frequency of an air slug at the opening, while CL controls the decay ratio of the fluctuating internal pressure. This study particularly focused on the value of loss coefficient and its influence factors including: opening configuration and location, internal volumes, as well as wind speed and approaching flow turbulence. A simplified formula was presented to predict loss coefficient, therefore an approximate relationship between the standard deviation of internal and external pressures can be estimated using Vickery\'s approach. The study shows that the loss coefficient governs the peak response of the internal pressure spectrum which, in turn, will directly influence the standard deviation of the fluctuating internal pressure. The approaching flow characteristic and opening location have a remarkable effect on the parameter CL.

Hydrothermal pretreatment of oxytetracycline fermentation residue: Removal of oxytetracycline and increasing the potential for anaerobic digestion

Mohammed Awad,Zhe Tian,Yu Zhang,Min Yang,Wenjuan Yin,Liping Dong 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.4

The presence of high level of antibiotics in the antibiotic fermentation residue is one of the main reasons that prevent their direct disposal or further use as a resource. In this study, the feasibility of using the hydrothermal pretreatment for removing oxytetracycline (OTC) from its fermentation residue and enhancing anaerobic digestion was evaluated under different temperatures i.e. 110, 130, 150 and 170℃. The results showed that the removal rate of OTC increased as a function of temperature, and hydrothermal treatment at 130℃ for 5 min was found sufficient to reduce the concentration of OTC from 3.9 ㎎/g to less than the detection limit (i.e., 0.25 ng/g). Biochemical methane potential tests showed that the cumulative methane production over 23 d was 73.7, 215.9, 656.8, and 439.0NmL CH₄/gVS for the raw residue and the residue treated at 130, 150, and 170℃ for 5 min, respectively. At the same time, the abundances of tetracycline resistance genes were reduced by hydrothermal treatments followed by anaerobic digestion. Conclusively, it is suggested that hydrothermal treatment at 150℃ for 5 min was found beneficial for OTC fermentation residues ensuring the removal of OTC and further use of the residue for anaerobic digestion.

Effects of Phytosterol Ester on the Fatty Acid Profiles in Rats with Nonalcoholic Fatty Liver Disease

Lihua Song,Haiyue Zhou,Wenjuan Yu,Xinwen Ding,Li Yang,Jiayi Wu,Chenwei Song 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.2

Both serum and hepatic fatty acid (FA) compositions differ among nonalcoholic hepatic steatosis, nonalcoholic steatohepatitis, and healthy subjects. The severity of the above liver disease is closely associated with the concentration and composition of FAs. Our previous study found that phytosterol ester (PSE) could alleviate hepatic steatosis in nonalcoholic fatty liver disease rats. The aims of this work were to explore the effects of PSE (0.05/100 g·body weight) on FA profiles and the mRNA levels of FA metabolism-related genes. Compared with a high-fat diet alone group, PSE treatment significantly decreased hepatic saturated fatty acid levels (P < .05) and increased monounsaturated fatty acid (especially C16:1 n-7) levels in the liver, serum, and adipose tissue and polyunsaturated fatty acid levels in the serum and liver (P < .05) after 12 weeks of intervention. In particular, PSE treatment increased the level of C22:5 n-3, an FA that was negatively correlated with the degree of hepatic steatosis in the serum, liver, and adipose tissue. The increases in some unsaturated fatty acids are probably related to the upregulation of stearoyl-coenzyme A desaturase-1 and fatty acid desaturase-1.