F-2 toxin is an estrogenic mycotoxin that causes reproductive disorders in animals.Betulinic acid(BA)is a natural pentacyclic lupane-structure triterpenoid that has diverse pharmacological activities.In this study,the...F-2 toxin is an estrogenic mycotoxin that causes reproductive disorders in animals.Betulinic acid(BA)is a natural pentacyclic lupane-structure triterpenoid that has diverse pharmacological activities.In this study,the antioxidative and anti-inflammatory effects of BA and its underlying mechanism are explored in F-2 toxin-triggered mouse ovarian damage.We found that BA alleviated the F-2 toxin-induced ovarian impairment by stimulating follicle growth,reducing inflammatory cell infiltration,repairing damaged mitochondria and endoplasmic reticulum.Simultaneously,BA not only reversed F-2 toxin-induced reduction of follicle stimulating hormone(FSH)and luteinizing hormone(LH)levels in the serum,but also restrained the protein expression of the estrogen receptors a(ERa)and ERβ.Moreover,BA restored the balance of F-2 toxin-induced ovarian redox system disorders.Subsequently,we found that 0.25 mg/kg BA played an anti-inflammatory role in the F-2 toxin-induced ovarian impairment by decreasing interleukin-1β(IL-1β).IL-6,and tumor necrosis factor-α(TNF-α)mRNA expression,as well as inhibiting p38 protein expression.These data demonstrated that BA exerts its protective effect on F-2 toxin-induced ovarian oxidative impairment and inflammation by inhibiting p38 expression,which implies a natural product-based medicine to ameliorate F-2 toxin-caused female reproductive toxicity and provides a detoxifying method for food contaminated by mycotoxin.展开更多
In this work,a force measurement system is proposed to measure the thrust of plasma microthruster with thrust magnitude ranging from sub-micro-Newtons to hundreds micro-Newtons.The thrust measurement system uses an el...In this work,a force measurement system is proposed to measure the thrust of plasma microthruster with thrust magnitude ranging from sub-micro-Newtons to hundreds micro-Newtons.The thrust measurement system uses an elastic torsional pendulum structure with a capacitance sensor to measure the displacement,which can reflect the position change caused by the applied force perpendicular to the pendulum axis.In the open-loop mode,the steady-state thrust or the impulse of the plasma micro-thruster can be obtained from the swing of the pendulum,and in the closed-loop mode the steady-state thrust can be obtained from the feedback force that keeps the pendulum at a specific position.The thrust respond of the system was calibrated using an electrostatic weak force generation device.Experimental results show that the system can measure a thrust range from 0 to 200μN in both open-loop mode and closed-loop mode with a thrust resolution of 0.1μN,and the system can response to a pulse bit at the magnitude of 0.1 m N s generated by a micro cathode arc thruster.The background noise of the closed-loop mode is lower than that of the open-loop mode,both less than 0.1 m N/Hz in the range of 10 mHz to 5 Hz.展开更多
A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS ...A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.展开更多
B7 family molecules are members of the imm unoglobulin superfamily.Their co-stimulatory and co-inhibitory molecules play a key role in the regulation of immune responses.In this study,the molecule BTN2A2 was selected ...B7 family molecules are members of the imm unoglobulin superfamily.Their co-stimulatory and co-inhibitory molecules play a key role in the regulation of immune responses.In this study,the molecule BTN2A2 was selected to predict crystal structure,analyze function,and detect expression.Bioinformatics was used to predict the structure of BTN2A2,and its identity and similarity with B7 family members and other BTN family members were analyzed.Real-time qPCR was used to detect the expression of BTN2A2 at the mRNA level in various tissues and organs of mice.BTN2A2 shares sequence and structural homology with the B7 family molecules,and BTN2A2 is a member of the BTN family with an Ig-like domain.At the mRNA level,BTN2A2 is highly expressed in immune organs.Compared with the non-onset NOD mice,the diseased NOD mice have higher expression of BTN2A2 in the pancreas of mRNA level,and have statistical significance(P<0.001).展开更多
基金supported by the National Natural Science Foundation of China (32273084)the Special Funds for Construction of Innovative Provinces in Hunan Province,China (2020NK2032)+2 种基金the Natural Science Foundation of Hunan Province,China (2020JJ4368)Innovation Foundation for Postgraduate of Hunan Province,China (CX20220670)Innovation Foundation for Postgraduate of Hunan Agricultural University,China (2022XC010)。
文摘F-2 toxin is an estrogenic mycotoxin that causes reproductive disorders in animals.Betulinic acid(BA)is a natural pentacyclic lupane-structure triterpenoid that has diverse pharmacological activities.In this study,the antioxidative and anti-inflammatory effects of BA and its underlying mechanism are explored in F-2 toxin-triggered mouse ovarian damage.We found that BA alleviated the F-2 toxin-induced ovarian impairment by stimulating follicle growth,reducing inflammatory cell infiltration,repairing damaged mitochondria and endoplasmic reticulum.Simultaneously,BA not only reversed F-2 toxin-induced reduction of follicle stimulating hormone(FSH)and luteinizing hormone(LH)levels in the serum,but also restrained the protein expression of the estrogen receptors a(ERa)and ERβ.Moreover,BA restored the balance of F-2 toxin-induced ovarian redox system disorders.Subsequently,we found that 0.25 mg/kg BA played an anti-inflammatory role in the F-2 toxin-induced ovarian impairment by decreasing interleukin-1β(IL-1β).IL-6,and tumor necrosis factor-α(TNF-α)mRNA expression,as well as inhibiting p38 protein expression.These data demonstrated that BA exerts its protective effect on F-2 toxin-induced ovarian oxidative impairment and inflammation by inhibiting p38 expression,which implies a natural product-based medicine to ameliorate F-2 toxin-caused female reproductive toxicity and provides a detoxifying method for food contaminated by mycotoxin.
基金supported by the Shanghai Engineering Research Center of Space Engine(No.17DZ2280800)。
文摘In this work,a force measurement system is proposed to measure the thrust of plasma microthruster with thrust magnitude ranging from sub-micro-Newtons to hundreds micro-Newtons.The thrust measurement system uses an elastic torsional pendulum structure with a capacitance sensor to measure the displacement,which can reflect the position change caused by the applied force perpendicular to the pendulum axis.In the open-loop mode,the steady-state thrust or the impulse of the plasma micro-thruster can be obtained from the swing of the pendulum,and in the closed-loop mode the steady-state thrust can be obtained from the feedback force that keeps the pendulum at a specific position.The thrust respond of the system was calibrated using an electrostatic weak force generation device.Experimental results show that the system can measure a thrust range from 0 to 200μN in both open-loop mode and closed-loop mode with a thrust resolution of 0.1μN,and the system can response to a pulse bit at the magnitude of 0.1 m N s generated by a micro cathode arc thruster.The background noise of the closed-loop mode is lower than that of the open-loop mode,both less than 0.1 m N/Hz in the range of 10 mHz to 5 Hz.
文摘A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.
文摘B7 family molecules are members of the imm unoglobulin superfamily.Their co-stimulatory and co-inhibitory molecules play a key role in the regulation of immune responses.In this study,the molecule BTN2A2 was selected to predict crystal structure,analyze function,and detect expression.Bioinformatics was used to predict the structure of BTN2A2,and its identity and similarity with B7 family members and other BTN family members were analyzed.Real-time qPCR was used to detect the expression of BTN2A2 at the mRNA level in various tissues and organs of mice.BTN2A2 shares sequence and structural homology with the B7 family molecules,and BTN2A2 is a member of the BTN family with an Ig-like domain.At the mRNA level,BTN2A2 is highly expressed in immune organs.Compared with the non-onset NOD mice,the diseased NOD mice have higher expression of BTN2A2 in the pancreas of mRNA level,and have statistical significance(P<0.001).
