Male Grapholita molesta (Busck) adults responding to various component combinations of synthetic female sex pheromone

Guo Yongfu,Wang Yi,Chai Xiaohan,Xiang Huiming,Kong Weina,Ma Ruiyan 한국곤충학회 2022 Entomological Research Vol.52 No.9

Grapholita molesta (Busck) is a cosmopolitan fruit pest. The sex pheromones released by females have four components, namely (Z)-8-dodecenyl acetate (Z8–12:Ac), E8–12:Ac, (Z)-8-dodecen-1-ol (Z8–12:OH), and dodecanol (12:OH). This multichemical attractive system has been reported to induce various male behavioral responses, from arousal to directional flight, and enhance trapping. However, the specific male behaviors induced by individual component or component blend is unclear. This study investigated the effects of different combinations of these four components using electroantennogram, wind tunnel assays, and field tests on aspects of male behavioral performance. Our results showed that the (Z8–12:Ac + E8–12:Ac)- containing pheromones were mainly responsible for long-distance detection and close-distance location in males, including antennal detection of the stimulus, flight initiation, directional flight, and trapping. The addition of E8–12:Ac to Z8–12:Ac plays an important role in pheromone searching behavior of males in close range. The ternary component, Z8–12:Ac + E8–12: Ac + Z8–12:OH was crucial for capturing male moths, and 12:OH significantly increased the male catch. The addition of Z8–12:OH and 12:OH to Z8–12: Ac + E8–12:Ac plays an important role in completing the whole response sequence in field attraction. This study revealed that Z8–12:Ac + E8–12:Ac acts as a attractant to males, whereas Z8–12:OH, and 12:OH are the synergists that enhance male attraction in the sex pheromone blend.

Determination of Hg2+ Based on the Selective Enhancement of Peroxidase Mimetic Activity of Hollow Porous Gold Nanoparticles

Mingzhen Guo,Jiang He,Shuang Ma,Xiaohan Sun,Mingda Zheng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.4

In this paper, a novel colorimetric biosensor for Hg2+ is presented based on Hg2+ stimulated peroxidase-like activity of hollow porous gold nanoparticles (HPGNPs). Under mild conditions, HPGNPs show high catalytic activity toward the oxidation of 3, 3' , 5, 5' -tetramethylbenzidine (TMB) using H2O2 as an oxidant. The peroxidase-like activity of HPGNPs is "switched-on" selectively in the presence of Hg2+, which permitted a novel and facile colorimetric sensor for Hg2+. This method exhibits many merits like high selectivity and sensitivity. As low as 18.5 nM Hg2+ could be determined at a linear range from 0.5 x 10 -6 M to 50 x 10 -6 M. This method is successfully applied for the determination of total mercury content in tap water and Yellow River which indicates that the method has a great potential for the routine determination of Hg2+ in environmental samples.

Numerical simulation of ice loads on a ship in broken ice fields using an elastic ice model

Wang, Chao,Hu, Xiaohan,Tian, Taiping,Guo, Chunyu,Wang, Chunhui The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

The finite element method is used to simulate the navigation of an ice-area bulk carrier in broken ice fields. The ice material is defined as elastic, and the simulations are accomplished at four model speeds and three ice concentrations. The movements of ice floes in the simulation are consistent with those in the model test, and the percentage deviation of the numerical ice resistance from the ice resistance in the model test can be controlled to be less than 15 %. The key characteristics of ice loads, including the average ice loads, extreme ice loads, and characteristic frequency, are analyzed thoroughly in a comprehensive manner. Moreover, the effects of sailing speed and ice concentration on the ice loads are analyzed. In particular, the stress distribution of ice floes is presented to help understand how model speed and concentration affect the ice loads. The "ice pressure" phenomenon is observed at 90 % ice concentration, and it is realistically reflected both in the time―and frequency―domain ice force curves.

Molecular mechanisms involved in epidermal growth factor receptor-mediated inhibition of dopamine D₃ receptor signaling

Sun, Ningning,Zhang, Xiaowei,Guo, Shuohan,Le, Hang Thi,Zhang, Xiaohan,Kim, Kyeong-Man Elsevier 2018 Biochimica et biophysica acta, Molecular cell rese Vol.1865 No.9

<P><B>Abstract</B></P> <P>The phenomenon wherein the signaling by a given receptor is regulated by a different class of receptors is termed transactivation or crosstalk. Crosstalk between receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs) is highly diverse and has unique functional implications because of the distinct structural features of the receptors and the signaling pathways involved. The present study used the epidermal growth factor receptor (EGFR) and dopamine D<SUB>3</SUB> receptor (D<SUB>3</SUB>R), which are both associated with schizophrenia, as the model system to study crosstalk between RTKs and GPCRs. Loss-of-function approaches were used to identify the cellular components involved in the tyrosine phosphorylation of G protein-coupled receptor kinase 2 (GRK2), which is responsible for EGFR-induced regulation of the functions of D<SUB>3</SUB>R. <I>SRC</I> proto-oncogene (Src, non-receptor tyrosine kinase), heterotrimeric G protein Gβγ subunit, and endocytosis of EGFR were involved in the tyrosine phosphorylation of GRK2. In response to EGF treatment, Src interacted with EGFR in a Gβγ-dependent manner, resulting in the endocytosis of EGFR. Internalized EGFR in the cytosol mediated Src/Gβγ-dependent tyrosine phosphorylation of GRK2. The binding of tyrosine-phosphorylated GRK2 to the T142 residue of D<SUB>3</SUB>R resulted in uncoupling from G proteins, endocytosis, and lysosomal downregulation. This study identified the molecular mechanisms involved in the EGFR-mediated regulation of the functions of D<SUB>3</SUB>R, which can be extended to the crosstalk between other RTKs and GPCRs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Stimulation of EGFR results in the tyrosine phosphorylation of GRK2. </LI> <LI> Gβγ, Src, and endocytosis of EGFR are required for the tyrosine phosphorylation of GRK2. </LI> <LI> Tyrosine phosphorylated GRK2 binds to T142 of D<SUB>3</SUB>R. </LI> <LI> GRK2-bound D<SUB>3</SUB>R is uncoupled from G proteins to result in signaling inhibition. </LI> <LI> GRK2-bound D<SUB>3</SUB>R undergoes endocytosis and degradation through lysosomal pathway. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Investigating the Characteristics of Wet Shotcrete Pipeline Transportation

Lianjun Chen,Jiahao Sun,Xiaohan Guo,Nan Guo,Yanan Huang,Guoming Liu 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.12

In order to study the resistance characteristics of wet shotcrete pipeline transportation, a small pipe type rheology and resistance test device was developed. The device is used for straight pipe resistance test, pump stop test and dyed concrete test were carried out on concrete with different characteristics. The fluidity changes of concrete with different characteristics were obtained through experiments. The results show that the slump, pressure bleeding rate, water-cement ratio were all negatively related to pipeline transportation resistance. The influence of the three factors on resistance was in order: pressure bleeding rate, water-cement ratio, slump. The dyed concrete test confirmed the principle of the plunger flow in the pipeline when concrete is pumped. The thickness of the lubricating layer increased with the increase of the water-cement ratio. The concrete pipeline transportation resistance increased with the increase of the standing time. The fitting curve was obtained through the correlation analysis between resistance and lubricating layer thickness, and the two were negatively correlated. This provides a new research idea for the study of drag reduction measures for concrete pipeline transportation.

Numerical simulation of ice loads on a ship in broken ice fields using an elastic ice model

Wang, Chao,Hu, Xiaohan,Tian, Taiping,Guo, Chunyu,Wang, Chunhui The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

The finite element method is used to simulate the navigation of an ice-area bulk carrier in broken ice fields. The ice material is defined as elastic, and the simulations are accomplished at four model speeds and three ice concentrations. The movements of ice floes in the simulation are consistent with those in the model test, and the percentage deviation of the numerical ice resistance from the ice resistance in the model test can be controlled to be less than 15 %. The key characteristics of ice loads, including the average ice loads, extreme ice loads, and characteristic frequency, are analyzed thoroughly in a comprehensive manner. Moreover, the effects of sailing speed and ice concentration on the ice loads are analyzed. In particular, the stress distribution of ice floes is presented to help understand how model speed and concentration affect the ice loads. The "ice pressure" phenomenon is observed at 90 % ice concentration, and it is realistically reflected both in the time―and frequency―domain ice force curves.

N-linked Glycosylation on the N-terminus of the dopamine D₂ and D₃ receptors determines receptor association with specific microdomains in the plasma membrane

( Chengchun Min ),( Mei Zheng ),( Xiaohan Zhang ),( Shuohan Guo ),( Kyoung-ja Kwon ),( Chan Young Shin ),( Hyeong-suk Kim ),( Seung Hoon Cheon ),( Kyeong-man Kim ) 전남대학교 약품개발연구소 2015 약품개발연구지 Vol.24 No.-

Numerous G protein-coupled receptots (GPCRs) are glycosylated at extacellular regions. The regulatory roles of glycosylation on receptor function vary across receptor types. In this study. we used the dopamine D₂ and D₃ receptors as an experimental model to understand the underlying principles governing the functional roles of glycosylation. We used the pharmacological inhibitor. tunicamycin, to inhibit glycosylation. generated chimeric D₂ and D₃ receptors by swapping their respective N-termini. and produced the glycosylation site mutant D₂ and D₃ receptors to study the roles of glycosylation on receptor functions, induding cell surface expression, signaling, and internalization through specific microdomains. Our results demonstrate that glycosylation on the N-terminus of the D₃ receptor is involved in the development of desensitization and proper cell surface expression. In addition, glycosylation on the N-terminus mediates the internalization of D₂ and D₃, receptors within the caveolae and clathrin-coated pit microdomains of the plasma membrane, respectively, by regulating receptor interactions with caveolin-1 and c1athrin. In conclusion, this study shows for the first time that glycosylation on the N-terminus of GPCRs is involved in endocytic pathway selection through specific microdomains. These data suggest that changes in the cellular environment that influence posttranslational modification could be an important determinant of intracellular GPCR trafficking.