Publications by authors named "Junkun Ma"

2 Publications

  • Page 1 of 1

Development of a Novel Finger-Trigger Interface for Trigger Pull Measurement.

J Forensic Sci 2020 Nov 13;65(6):1954-1960. Epub 2020 Aug 13.

Department of Forensic Science, College of Criminal Justice, Sam Houston State University, Huntsville, TX, 77340.

Trigger pull is the force that needs to be exerted on the trigger to discharge a firearm. The measurement of trigger pull can assist in the evaluation of the safety, function, and manufacturing characteristics associated with a firearm during the forensic firearm examination process. Nonetheless, the accuracy and uncertainty of trigger pull measurements may be affected by the measuring device, test procedure, and environmental conditions. In this work, an innovative finger-trigger interface device was developed to facilitate accurate trigger pull measurements. The idea was to reduce the variation related to the position of the measurement device on the trigger in existing measuring methods and devices. Three force sensors based on different technologies were initially evaluated. While two of the three sensors failed to produce data, the miniature capacitive plate sensor exhibited high precision and a linear response over the range of typical trigger pulls. To examine the effects of the finger-trigger interface on trigger pull measurement, different sensor housing prototypes were designed in silico and 3D printed for the construction of three finger-trigger interface devices. The performance of each finger-trigger interface device was evaluated by measuring the trigger pulls of several selected firearms and comparing the data to a previously published study. Our preliminary results demonstrated the novel finger-trigger interface device offered a new way to measure trigger pull in situ with acceptable accuracy and precision.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/1556-4029.14538DOI Listing
November 2020

Selenium Attenuates Staphylococcus aureus Mastitis in Mice by Inhibiting the Activation of the NALP3 Inflammasome and NF-κB/MAPK Pathway.

Biol Trace Elem Res 2019 Sep 7;191(1):159-166. Epub 2018 Dec 7.

Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.

Mastitis is one of the most important diseases affecting the dairy industry in the world, and it also poses a great threat to human food safety. In this study, we explored whether selenium can inhibit the activation of the NALP3 inflammasome and NF-κB/MAPK pathway to achieve anti-inflammatory effects. Sixty BALB/c female mice were randomly divided into three groups according to diets of different selenium concentrations (high, normal, and low). After 90 days, mice fed the same selenium concentration were randomly divided into two smaller groups, one of which was inoculated with Staphylococcus aureus and the other injected with saline as a control. Through histopathologic examination staining, western blot, qPCR, and ELISA, the results showed that with increasing selenium concentrations, the expression levels of IL-1β, TNF-α, NALP3, caspase-1, and ASC were decreased in mouse mammary tissue. Therefore, this study revealed that selenium can attenuate S. aureus mastitis by inhibiting the activation of the NALP3 inflammasome and NF-κB/MAPK pathway.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12011-018-1591-8DOI Listing
September 2019