A study on nontuberculous mycobacteria （NTM） was carried out in wildlife-livestock interface of Katavi Rukwa ecosystem （KRE）. 328 livestock tissues and 178 wild animals were cultured, wild animals were sampled opp...A study on nontuberculous mycobacteria （NTM） was carried out in wildlife-livestock interface of Katavi Rukwa ecosystem （KRE）. 328 livestock tissues and 178 wild animals were cultured, wild animals were sampled opportunistically during professional hunting and game cropping operations in the KRE protected areas. The objective of the study was to generate data on epidemiology of NTM in the wildlife-livestock interface of the KRE. Methods used to identify the NTM were： culture and isolation, polymerase chain reaction, protein heat shock 65 kilodalton （hsp65） and sequencing. Mycobacteria were detected on 25.9% and 11.9% of livestock and wildlife tissue cultures, respectively. The most NTM isolated were M. kansasii （30%）, M. gastri （30%）, M. fortuitum （1%）, M. intracellulare （4%）, M. indicuspranii （4%）, M. nonchromogenicum （6%） and M. lentiflavum （6%）. Other NTM in smaller percentages were M. hibernae, M. engbaekii, M. septicum, M. arupense and 34.. godii. Due to rise of NTM infection in both human and animals, it is recommended that awareness and laboratory facilities be improved to curb the underreporting especially in TB-endemic countries. For species specific identification, a network of national and regional laboratories is promoted.展开更多
Post-bond heat treatment(PBHT) applied to a transient liquid phase(TLP) bonding joint is an effective approach to remove the brittle borides and improve its properties.Herein,we proposed two types of PBHT strategies t...Post-bond heat treatment(PBHT) applied to a transient liquid phase(TLP) bonding joint is an effective approach to remove the brittle borides and improve its properties.Herein,we proposed two types of PBHT strategies to obtain a TLP bonded γ'-strengthened Co-based single crystal superalloy,and the microstructural characteristics and tensile properties of the two heat treated joints were compared to identify the optimal PBHT strategy.The evolution of the brittle boride in the joint after the PBHT was studied by using in-situ microscopy.The experimental results allowed to provide a theoretic model to quantitatively evaluate the distribution of the brittle phase after the optimal PBHT and analyze the joint fractures to understand the failure mechanisms.The obtained results revealed that a post-bond solid solution treatment performed to the joint at a high temperature(over 1275℃) could decrease the area fraction of the boride from 7.2 % to 1.4 % and increase the elongation from 1.9 % to 7.8 %.This work emphasizes the relevance of solid solution temperature when a PBHT strategy is applied.展开更多
文摘A study on nontuberculous mycobacteria （NTM） was carried out in wildlife-livestock interface of Katavi Rukwa ecosystem （KRE）. 328 livestock tissues and 178 wild animals were cultured, wild animals were sampled opportunistically during professional hunting and game cropping operations in the KRE protected areas. The objective of the study was to generate data on epidemiology of NTM in the wildlife-livestock interface of the KRE. Methods used to identify the NTM were： culture and isolation, polymerase chain reaction, protein heat shock 65 kilodalton （hsp65） and sequencing. Mycobacteria were detected on 25.9% and 11.9% of livestock and wildlife tissue cultures, respectively. The most NTM isolated were M. kansasii （30%）, M. gastri （30%）, M. fortuitum （1%）, M. intracellulare （4%）, M. indicuspranii （4%）, M. nonchromogenicum （6%） and M. lentiflavum （6%）. Other NTM in smaller percentages were M. hibernae, M. engbaekii, M. septicum, M. arupense and 34.. godii. Due to rise of NTM infection in both human and animals, it is recommended that awareness and laboratory facilities be improved to curb the underreporting especially in TB-endemic countries. For species specific identification, a network of national and regional laboratories is promoted.
基金financially supported by the Project from the National Natural Science Foundation of China under Grant(No.51771191)the National Key Research and Development Program of China under Grant(No.2017YFA0700704)the Aerospace Power Foundation under Grant(DLJJ1825)。
文摘Post-bond heat treatment(PBHT) applied to a transient liquid phase(TLP) bonding joint is an effective approach to remove the brittle borides and improve its properties.Herein,we proposed two types of PBHT strategies to obtain a TLP bonded γ'-strengthened Co-based single crystal superalloy,and the microstructural characteristics and tensile properties of the two heat treated joints were compared to identify the optimal PBHT strategy.The evolution of the brittle boride in the joint after the PBHT was studied by using in-situ microscopy.The experimental results allowed to provide a theoretic model to quantitatively evaluate the distribution of the brittle phase after the optimal PBHT and analyze the joint fractures to understand the failure mechanisms.The obtained results revealed that a post-bond solid solution treatment performed to the joint at a high temperature(over 1275℃) could decrease the area fraction of the boride from 7.2 % to 1.4 % and increase the elongation from 1.9 % to 7.8 %.This work emphasizes the relevance of solid solution temperature when a PBHT strategy is applied.
