Objective To contrastively study the effects of NERC-300 high frequency welding device and ultrasonic scalpel in rat partial hepatectomy.Methods Forty-eight rats were divided into the experimental group and control group(n=24).The experimental group applied NERC-300 high frequency welding instrument for conducting partial hepatectomy,while the control group used ultrasonic scalpel.The survival rate,operation time,bleeding volume,working temperature,extent of hepatic thermal damage and change of liver function on 1,3,7 d were compared between the two groups.Results The liver function recovery on 3 d in the experimental group was superior to the control group (P＜0.05).The intra-operative working temperature in the experimental group was lower than that in the control group(P＜0.05).The thermal damage range in the experimental group was lower than that in the control group(P＜0.05).The survival rate,operation time,bleeding volume and liver function change on 1,7 d had no statistical differences between the two groups(P＞0.05).Conclusion NERC-300 high frequency welding device is safe and effective for partial hepatectomy in rat.

ObjectiveTo investigate the population and chigger mite infection of rodents in Pudong District， Shanghai， so as to provide the scientific basis for the prevention and control of rodents and chigger transmitted diseases. MethodsThe monitoring work was conducted in four points including Xuanqiao， Hangtou， Laogang and Nanhui New Town with night trapping method from 2020 to 2022. Habitats as farmland， wasteland， rural residential areas， and parks were selected. The rodent species were identified and rodent density was calculated. All chigger mites were collected from the earlaps and auricular fossae of the rodents. The species of chigger mites were identified and the chigger mite index was calculated. ResultsA total of 222 rodents were captured. They belonged to 5 species， 4 genera， 2 families and 2 orders， including 4 species， 3 genera， and 1 family of Rodentia and 1 species of Insectivora. M. musculus was the dominant species， with a composition ratio of 54.05%. Total 80 chigger mites were captured， with a detection rate of 36.03%. The total chigger index was 0.36 and Rattus tanezumi held the highest （6.00）， followed by M. musculus （0.48）. There were 3 species of chigger mites， L.deliense， L.scutellare， and L.gaohuense. L.deliense was the dominant specie， accounting for 55.00%. ConclusionThere is a risk of chigger-borne disease transmission in Pudong New Area with M. musculus as the dominant host and L. deliense as the dominant species.

ObjectiveTo describe the differences in imported malaria cases before and after the COVID-19 pandemic in Pudong New Area， Shanghai， to explore the possible impact of isolation measures during the pandemic on malaria， and to provide a basis for formulation of malaria control strategies during the prevention and control of major infectious diseases in the future. MethodsInformation on malaria cases reported in Pudong New Area from 2017 to 2022 was collected and divided into two groups： cases before the COVID-19 pandemic （2017‒2019） and cases after the COVID-19 pandemic （2020‒2022）. Analysis was conducted on information such as gender， age， parasite species， country of infection， place of onset， time of onset， time of first diagnosis， time of confirmed diagnosis， hospitalization， and duration of treatment for both groups. ResultsThe pre-COVID group consisted of 21 cases， and post-COVID group consisted of 28 cases， with male and falciparum malaria predominating in both groups. There were statistically significant differences between the two groups in terms of Shanghai residency status， use of preventive measures， and adherence to standardized treatment （P<0.05）. The time interval from symptom onset to first diagnosis was longer in the pre-COVID group than that in the post-COVID group （Z=-2.617， P<0.05 ）. The interval from the first diagnosis to the confirmed diagnosis and duration of treatment were shorter in the pre-COVID group than that in the post-COVID group （Z=-3.381， P<0.05； Z=-4.148， P<0.05）. There was no significant difference in gender， age， malaria classification， source of infection， onset area， length of hospital stay， complications， severe cases， and interval between onset and diagnosis between the two groups （P>0.05）. ConclusionAfter the outbreak of COVID-19， the medical priority plan prolongs the treatment time of malaria patients， increasing the risk of severe illness and death.