The Local Alternative Ti-6Al-4V Alloy Coating of Surgery Steel Instruments for Laser Deposition Forming / 中国医疗器械杂志

Aiming at the medical practice problems of the surgical steel medical instruments, such as the crevice corrosion, the poor mechanical compatibility and the Ni, Cr plasma exudation, the laser deposition of Ti-6Al-4V alloy cladding layer at the local functional area as alternative coating was proposed and realized as a new process method. The accurate element content and good formability Ti-6Al-4V cladding powder was chosen, the low power and high duty cycle optimized laser process was adopt, the alternative coating of good fusion and low dilution was prepared. Through the elemental line scanning, the interface microstructure analysis and the experiments of basic mechanical properties, the basic properties of the cladding were characterized and verified. The experiments results showed that, the Ti, Al and V contents of the top coating were respectively about 88%, 4.9% and 3.9%, no sensitizing ions such as Cr and Ni were detected. Initial equiaxed α phase, flake β phase dist were distributed in the coating and interface, the α' martensite was precipitated at the boundary of the flake β phase, some refined granular β phase dispersion pinned to the grain boundary of basket structure. The microhardness of cladding layer was 352.08~312.76 HV0.1. The friction coefficient of the cladding layer was about 0.22~0.65. A new technology and method reference for improving and upgrading the performance of surgical medical devices is provided by this research.

Epidemiological characteristics of outpatients exposed to rabies in Weinan City in 2017 / 中华微生物学和免疫学杂志

Objective To investigate the epidemiological characteristics of outpatients exposed to rabies and to analyze the post-exposure prophylaxis in Weinan City in 2017 in order to provide a scientific basis for the prevention of rabies. Methods Clinical data of all outpatients with exposure to rabies in Wei-nan were collected. Ecxcel 2007 was used for data entry and SPSS13. 0 for Chi-square test. Results A total of 32 094 cases were reported with an annual exposure rate of 625. 64/100 000 in Weinan in 2017. Animal bites mainly occurred in spring and summer,accounting for 47. 47% of the total cases in 2017. There were statistically differences in exposure rate among different age groups (χ2=15. 858,P=0. 003). Farmers ac-counted for the largest proportion of the outpatients exposed to rabies (52. 34% ). Among 31 435 outpatients, 28 181(89. 65% ) received wound care and rabies vaccination. The vaccination rate of rabies immunoglobu-lin for patients with gradeⅢ exposure was 46. 93%. Conclusion Comprehensive measures with focuses on compulsory vaccination for domestic dogs and adoption of stray dogs should be implemented to prevent human rabies. Meanwhile,health education rabieson prevention and control should also be strengthened.