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2. Resistance of Aedes albopictus to commonly used insecticides in Jinshan District, Shanghai.

Author

LI Jing, WANG Tang, CHEN Ruyan, XU Feng, DONG Zhaopeng, and LIU Hongxia

Abstract

Objective To investigate the resistance level of Aedes albopictus to commonly used insecticides in Jinshan District, Shanghai, to provide a reference for standardizing the use of insecticides. Methods The larval dipping test was used to detect the resistance of Ae. Albopictus larvae to five kinds of insecticides, the SPSS 18.0 software was utilized to calculate the toxic regression equation and the median lethal concentration (LC50) of insecticides on the larvae. The resistance level was determined by evaluating the 24-hour mortality of adult Ae. Albopictus exposed to diagnostic doses of commonly used insecticides with the adult mosquito contact tube method. Results In 2018 and 2019, Ae. Albopictus larvae in the Jinshan District of Shanghai displayed moderate and high resistance to beta-cypermethrin, with resistance ratios of 25.03 and 65.96 folds respectively; high resistance to deltamethrin, with resistance ratios of 57.25 and 211.75 folds respectively; high resistance to permethrin, with resistance ratios of 46.17 and 243.36 folds. In 2018, 2019, 2021, and 2023, they showed moderate to high resistance to temephos with resistance ratios of 19.55, 23.94, 53.48, and 22.12 folds respectively. In 2021 and 2023, moderate resistance to fenitrothion was observed, with resistance ratios of 30.04 and 12.54 folds respectively. Adult Ae. Albopictus adults exhibited resistance to 0.03% deltamethrin, 0.07% lambda-cyhalothrin, 0.4% permethrin, and 0.08% beta-cypermethrin, with mortality rates ranging from 17.20% to 49.67% in 2021 and 2023. Potential resistance was observed to 0.7% lambdacyhalothrin and 0.2% fenitrothion, with mortalities of 97.48% and 83.74% respectively. Sensitivity was noted to 0.05% propoxur with a mortality rate of 100.00%. Conclusions Ae. Albopictus in the Jinshan District, Shanghai, has developed varying resistance levels to different types of insecticides, including pyrethroids and organophosphates. It is recommended to strengthen the dynamic monitoring of the resistance of Ae. Albopictus and implement comprehensive prevention and control measures with a focus on environmental management, scientifically and rationally selecting hygienic insecticides to delay and mitigate the emergence of resistance. [ABSTRACT FROM AUTHOR]

Published
2024
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5. High-Precision Acquisition Method of Position Signal of Permanent Magnet Direct Drive Servo Motor at Low Speed.

Author

Zhang, Deli, Dong, Zhaopeng, Bu, Feifei, Gu, Zijie, and Guo, Zitao

Subjects
*SERVOMECHANISMS, *PERMANENT magnets, *PERMANENT magnet motors, *CLOSED loop systems, *SPEED
Abstract

This paper studies a method for high-precision acquisition of position signals for permanent magnet direct drive servo motors at low speed. First of all, the problem of poor position feedback accuracy and sensor feedback delay in the low-speed operation of the permanent magnet direct drive servo motor is analyzed. Secondly, through analysis and simulation, it is found that the interpolation method can play a certain role in compensating the rotor position signal. However, when the speed is close to 0, the output signal of the sensor will fluctuate in a short time, which will affect the speed control accuracy. Therefore, this paper uses the observer method to achieve high-precision acquisition of the position signal of the permanent magnet direct drive servo motor at low speed. The observer method adopts the idea of combining the system model and closed-loop control. Additionally, it makes full use of the parameter information of the motor system. The control performance of the motor can be better guaranteed through the design of the observer parameters and the accuracy of the rotor position estimation result has been greatly improved. Finally, an experimental platform for permanent magnet direct drive servo motors is built, and the rotor position signal acquisition method based on the observer method is verified to have good performance through simulation and experiments. Not only the accuracy of the rotor position estimation result is improved, but also the motor control performance is improved, realizing the stable operation of the permanent magnet direct drive servo motor at low speed. [ABSTRACT FROM AUTHOR]

Published
2023
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10. Characterization of an inactivated whole-virus bivalent vaccine that induces balanced protective immunity against coxsackievirus A6 and A10 in mice

Author

Dong Li, Dong Zhaopeng, Weifeng Shi, Tao Liu, Zhenjie Zhang, Michael J. Carr, Juan Li, and Qian Wang

Subjects
0301 basic medicine, Injections, Subcutaneous, Coxsackievirus, Active immunization, Antibodies, Viral, Herpangina, Virus, 03 medical and health sciences, Immune system, Antigen, Medicine, Animals, Enterovirus, Mice, Inbred ICR, General Veterinary, General Immunology and Microbiology, biology, business.industry, Immunogenicity, Public Health, Environmental and Occupational Health, Immunization, Passive, Viral Vaccines, medicine.disease, biology.organism_classification, Antibodies, Neutralizing, Disease Models, Animal, 030104 developmental biology, Infectious Diseases, Vaccines, Inactivated, Immunoglobulin G, Immunology, biology.protein, Molecular Medicine, Female, Antibody, business, Hand, Foot and Mouth Disease, Immunity, Maternally-Acquired
Abstract

Coxsackievirus A6 (CVA6) and CVA10 are two of the major pathogens associated with hand, foot and mouth disease (HFMD) in children. The majority of CVA6 and CVA10 infections result in mild, self-limiting episodes (fever and herpangina) in pediatric populations; however, in some cases, can proceed to severe neurological disease and death. Efforts to mitigate viral transmission to decrease the morbidity and mortality associated with infection would be greatly strengthened by the availability of an efficacious CVA6 and CVA10 bivalent vaccine. Here we report the immunogenicity and protective efficacy of a bivalent combination vaccine comprised of formaldehyde-inactivated, whole-virus CVA6 and CVA10. We demonstrate that subcutaneous delivery of the bivalent vaccine can induce antigen-specific systemic immune responses, particularly the induction of polyfunctional T cells, which elicit active immunization to achieve a protection rate of >80% in the infected neonatal mice. Furthermore, passive transfer of the antisera from vaccinated mice potently protected recipient mice against CVA6 and CVA10 challenge. Importantly, the bivalent vaccine could induce high levels of IgG and neutralizing antibodies in adult female mice and the maternal antibody transmitted to the recipient mice played an important role in controlling homotypic and heterotypic CVA6 and CVA10 infections and viral replication in vivo. Collectively, these findings indicate that there is no immunological interference between the two antigens with respect to their ability to induce virus-specific immune responses, and thus provides proof-of-concept for further development of multivalent vaccines for broad protection against HFMD.

Published
2017

12. A Neonatal Murine Model of Coxsackievirus A6 Infection for Evaluation of Antiviral and Vaccine Efficacy

Author

Qingjuan Wei, Juan Li, Dong Li, Shujun Ding, Weifeng Shi, Zhenjie Zhang, Dong Zhaopeng, Michael J. Carr, and Yigang Tong

Subjects
0301 basic medicine, Male, medicine.disease_cause, Antibodies, Viral, Pathogenesis, chemistry.chemical_compound, Mice, Child, Lung, Cells, Cultured, Mice, Inbred ICR, Vaccination, Viral Load, Viral pneumonia, Encephalitis, Female, Viral load, Immunology, Pneumonia, Viral, Biology, Coxsackievirus, Microbiology, Antiviral Agents, 03 medical and health sciences, Interferon-gamma, Virology, Ribavirin, medicine, Animals, Humans, Muscle, Skeletal, Interleukin-6, Immunization, Passive, Viral Vaccines, medicine.disease, Vaccine efficacy, biology.organism_classification, Antibodies, Neutralizing, Enterovirus A, Human, Disease Models, Animal, Viral Tropism, 030104 developmental biology, chemistry, Vaccines, Inactivated, Insect Science, Enterovirus, Pathogenesis and Immunity, Hand, Foot and Mouth Disease
Abstract

Hand, foot, and mouth disease (HFMD) is a global health concern. Family Picornaviridae members, particularly enterovirus A71 (EVA71) and coxsackievirus A16 (CVA16), are the primary etiological agents of HFMD; however, a third enterovirus A species, CVA6, has been recently associated with epidemic outbreaks. Study of the pathogenesis of CVA6 infection and development of antivirals and vaccines are hindered by a lack of appropriate animal models. We have developed and characterized a murine model of CVA6 infection that was employed to evaluate the antiviral activities of different drugs and the protective efficacies of CVA6-inactivated vaccines. Neonatal mice were susceptible to CVA6 infection via intramuscular inoculation, and the susceptibility of mice to CVA6 infection was age and dose dependent. Five-day-old mice infected with 10 5.5 50% tissue culture infective doses of the CVA6 WF057R strain consistently exhibited clinical signs, including reduced mobility, lower weight gain, and quadriplegia with significant pathology in the brain, hind limb skeletal muscles, and lungs of the infected mice in the moribund state. Immunohistochemical analysis and quantitative reverse transcription-PCR (qRT-PCR) analyses showed high viral loads (11 log 10 /mg) in skeletal muscle, and elevated levels of interleukin-6 (IL-6; >2,000 pg/ml) were associated with severe viral pneumonia and encephalitis. Ribavirin and gamma interferon administered prophylactically diminished CVA6-associated pathology in vivo , and treatment with IL-6 accelerated the death of neonatal mice. Both specific anti-CVA6 serum and maternal antibody play important roles in controlling CVA6 infection and viral replication. Collectively, these findings indicate that this neonatal murine model will be invaluable in future studies to develop CVA6-specific antivirals and vaccines. IMPORTANCE Although coxsackievirus A6 (CVA6) infections are commonly mild and self-limiting, a small proportion of children may have serious complications, such as encephalitis, acute flaccid paralysis, and neurorespiratory syndrome, leading to fatalities. We have established a mouse model of CVA6 infection by inoculation of neonatal mice with a CVA6 clinical isolate that produced consistent pathological outcomes. Here, using this model of CVA6 infection, we found that high levels of IL-6 were associated with severe viral pneumonia and encephalitis, as in an evaluation of antiviral efficacy in vivo , IL-6 had no protective effect and instead accelerated death in neonatal mice. We demonstrated that, as antiviral drugs, both gamma interferon and ribavirin played important protective roles in the early stages of infection, with increased survival in treated neonatal mice challenged with CVA6. Moreover, active and passive immunization with the inactivated vaccines and anti-CVA6 serum also protected mice against homologous challenge infections.

Published
2017

18. Protective Efficacies of Formaldehyde-Inactivated Whole-Virus Vaccine and Antivirals in a Murine Model of Coxsackievirus A10 Infection

Author

Shujun Ding, Jianxing Wang, Ya-Wei Zhang, Yigang Tong, Zhenjie Zhang, Juan Li, Dong Zhaopeng, Michael J. Carr, Weifeng Shi, Dongming Zhuang, and Dong Li

Subjects
0301 basic medicine, Immunology, Coxsackievirus Infections, Biology, Coxsackievirus, Antibodies, Viral, Virus Replication, Microbiology, Herpangina, Antiviral Agents, Injections, Intramuscular, Proinflammatory cytokine, 03 medical and health sciences, chemistry.chemical_compound, Interferon-gamma, Immune system, Virology, Ribavirin, medicine, Animals, Interleukin 6, Enterovirus, Mice, Inbred ICR, Immunization, Passive, Viral Vaccines, medicine.disease, biology.organism_classification, Antibodies, Neutralizing, Disease Models, Animal, 030104 developmental biology, Treatment Outcome, chemistry, Immunization, Vaccines, Inactivated, Insect Science, Viral pneumonia, biology.protein, Pathogenesis and Immunity, Immunity, Maternally-Acquired
Abstract

Coxsackievirus A10 (CVA10) is one of the major pathogens associated with hand, foot, and mouth disease (HFMD). CVA10 infection can cause herpangina and viral pneumonia, which can be complicated by severe neurological sequelae. The morbidity and mortality of CVA10-associated HFMD have been increasing in recent years, particularly in the pan-Pacific region. There are limited studies, however, on the pathogenesis and immunology of CVA10-associated HFMD infections, and few antiviral drugs or vaccines have been reported. In the present study, a cell-adapted CVA10 strain was employed to inoculate intramuscularly 5-day-old ICR mice, which developed significant clinical signs, including reduced mobility, lower weight gain, and quadriplegia, with significant pathology in the brain, hind limb skeletal muscles, and lungs of infected mice in the moribund state. The severity of illness was associated with abnormally high expression of the proinflammatory cytokine interleukin 6 (IL-6). Antiviral assays demonstrated that ribavirin and gamma interferon administration could significantly inhibit CVA10 replication both in vitro and in vivo . In addition, formaldehyde-inactivated CVA10 whole-virus vaccines induced immune responses in adult mice, and maternal neutralizing antibodies could be transmitted to neonatal mice, providing protection against CVA10 clinical strains. Furthermore, high-titer antisera were effective against CVA10 and could relieve early clinical symptoms and improve the survival rates of CVA10-challenged neonatal mice. In summary, we present a novel murine model to study CVA10 pathology that will be extremely useful in developing effective antivirals and vaccines to diminish the burden of HFMD-associated disease. IMPORTANCE Hand, foot, and mouth disease cases in infancy, arising from coxsackievirus A10 (CVA10) infections, are typically benign, resolving without any significant adverse events. Severe disease and fatalities, however, can occur in some children, necessitating the development of vaccines and antiviral therapies. The present study has established a newborn-mouse model of CVA10 that, importantly, recapitulates many aspects of human disease with respect to the neuropathology and skeletal muscle pathology. We found that high levels of the proinflammatory cytokine interleukin 6 correlated with disease severity and that ribavirin and gamma interferon could decrease viral titers in vitro and in vivo . Whole-virus vaccines produced immune responses in adult mice, and immunized mothers conferred protection on neonates against challenge from CVA10 clinical strains. Passive immunization with high-titer antisera could also improve survival rates in newborn animals.

Published
2017

22. Computational fluid dynamics analysis and PIV validation of a bionic vortex flow pulsatile LVAD.

Author

Liang Xu, Ming Yang, Lin Ye, Zhaopeng Dong, Xu, Liang, Yang, Ming, Ye, Lin, and Dong, Zhaopeng

Subjects
HEART assist devices, PARTICLE image velocimetry, COMPUTATIONAL fluid dynamics, BIOCOMPATIBILITY, FLUX flow, PULSATILE flow, AORTA physiology, AORTA, HEART ventricles, BIOLOGICAL models, BIONICS, BLOOD flow measurement, COMPUTER simulation, HEMODYNAMICS, ANATOMY, PHYSIOLOGY
Abstract

Background: Hemocompatibility is highly affected by the flow field in Left Ventricular Assistant Devices (LVAD).Objective: An asymmetric inflow and outflow channel arrangement with a 45° intersection angle with respect to the blood chamber is proposed to approximate the vascular structure of the aorta and left atrium on the left ventricle. The structure is expected to develop uninterruptible vortex flow state which is similar to the flow state in human left ventricle.Methods: The Computational Fluid Dynamics (CFD) asymmetric model is simulated using ANSYS workbench. To validate the velocity field calculated by CFD, a Particle Image Velocimetry (PIV) experiment is conducted.Results: The CFD results show that the proposed blood chamber could generate a shifting vortex flow that would be redirected to the aorta during ejection to form a persistent recirculating flow state, which is similar to the echocardiographic flow state in left ventricle. Both the PIV and the CFD results show the development of a persistent vortex during the pulsatile period. Comparison of the qualitative flow pattern and quantitative probed velocity histories in a pulsatile period shows a good agreement between the CFD and PIV data.Conclusion: The goal of developing persistent quasi intra-ventricle vortex flow state in LVAD is realized. [ABSTRACT FROM AUTHOR]

Published
2015
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23. [Establishment of a Model of Infection by Enterovirus 71 in ICR Mice].

Author

Dong Z, Zhang Z, Yang L, Li D, and Shi W

Subjects
Animals, Animals, Newborn virology, Brain pathology, Brain virology, Enterovirus A, Human genetics, Enterovirus Infections pathology, Female, Heart virology, Humans, Male, Mice, Mice, Inbred ICR, Muscles pathology, Muscles virology, Disease Models, Animal, Enterovirus A, Human physiology, Enterovirus Infections virology
Abstract

We aimed to study infections in neonatal ICR mice of different ages infected with Enterovirus 71(EV-A71)through three routes of infection, and to explore the dynamic distribution and infection mechanism of EV-A71 in vivo.Three-,5-and 9-day-old neonatal ICR mice were infected with an EV-A71 strain isolated from a child with severe hand, foot and mouth disease through intramuscular(IM), intraperitoneal (IP)and intracerebral (IC)injection, respectively. Consequently, blood, brain, hind-limb muscle, heart, and intestines of mice were collected at regular intervals. Changes in viral load in organs were measured using real-time polymerase chain reaction. Hematoxylin and eosin staining and immunohistochemical (IHC)analyses were undertaken to detect pathogenic and pathologic changes in infected mice.Five-day-old neonatal mice infected with EV-A71 through IM,IP or IC routes had obvious neurologic symptoms and a high mortality rate. Symptoms were alleviated slightly with increasing age of mice upon injection. However, the pathogenicity associated with IM and IP injections was more severe than that of IC injection. Also, the mortality rates of IM and IP injections were significantly higher than that of IC injection. Compared with the control group, the mean body weight(in g)of 3-day-old neonatal mice at 6days post-infection(dpi)injected by IM,IP and IC routes decreased by 1.54(31.43%),1.31(15.06%)and 2.52(44.28%),respectively. Similarly, the mean body weight(in g)of 5-day-old neonatal mice at 6dpi injected by IM and IP decreased by 0.605(8.95%),0.886(15.51%),whereas that of mice injected by IC increased by 0.904(14.70%).The body weight of all infection groups was significantly lower than that of the control group(P<0.05).All 3-day-old neonatal mice infected with EV-A71 through IM,IP and IC routes died at 9dpi.Survival rates of 5-day-old neonatal mice infected through IM,IP and IC routes at 9dpi and14 dpi were 42.8%,25%,and 87.5%,and 0%,0%,and 25%,respectively.Those of 9-day-old neonatal mice at 14 dpi were 70%,69.23% and 100%,respectively.Pathologic and IHC examination showed that EV-A71 had a strong preference for infecting nervous systems and skeletal muscle, and could also lead to: viremia; necrosis of brain neurons and skeletal muscle; myocardial interstitial edema; inflammatory response of multiple organs. These data suggest that 5-day-old ICR neonatal mice injected through IM or IP routes can establish an ideal model of infection by EV-A71 in mice.

Published
2016

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