Introduction: The epidemiology of both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among drug users (DUs) is little known in West Africa. The study aimed to assess the prevalence of hepatitis B and ...Introduction: The epidemiology of both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among drug users (DUs) is little known in West Africa. The study aimed to assess the prevalence of hepatitis B and C viruses among drug users in Burkina Faso. Methodology: This was a cross-sectional biological and behavioral survey conducted between June and August 2022, among drug users in Ouagadougou and Bobo Dioulasso, the two main cities of Burkina Faso. A respondent-driven sampling (RDS) was used to recruit drug users. Hepatitis B surface antigen was determined using lateral flow rapid test kits and antibodies to hepatitis C virus in serum determined using an Enzyme-Linked Immunosorbent Assay. Data were entered and analyzed using Stata 17 software. Weighted binary logistic regression was used to identify the associated factors of hepatitis B and C infections and a p-value Results: A total of 323 drug users were recruited with 97.5% males. The mean age was 32.7 years old. The inhaled or smoked mode was the most used by drug users. The adjusted hepatitis B and hepatitis C prevalence among study participants were 11.1% and 2.3% respectively. The marital status (p = 0.001), and the nationality (p = 0.011) were significantly associated with hepatitis B infection. The type of drug used was not significantly associated with hepatitis B infection or hepatitis C infection. Conclusion: The prevalence of HBsAg and anti-HCV antibodies among DUs are comparable to those reported in the general population in Burkina Faso. This result suggests that the main routes of contamination by HBV and HCV among DUs are similar to those in the population, and could be explained by the low use of the injectable route by DUs in Burkina Faso.展开更多
Bovine tuberculosis (bTB) is an endemic zoonosis significantly affects animal health in Burkina Faso. The primary causative agent is Mycobacterium tuberculosis (M. tuberculosis) complex, mainly M. bovis. Cattle are co...Bovine tuberculosis (bTB) is an endemic zoonosis significantly affects animal health in Burkina Faso. The primary causative agent is Mycobacterium tuberculosis (M. tuberculosis) complex, mainly M. bovis. Cattle are considered as natural reservoir of M. bovis. However, in Burkina Faso, the circulation of these strains remains poorly understood and documented. This study aimed to identify and characterize Mycobacterium strains from suspected carcasses during routine meat inspection at Bobo-Dioulasso refrigerated slaughterhouse. A prospective cross-sectional study was conducted from January 2021 to December 2022 on cases of seizures linked to suspected bovine tuberculosis. Microbiological and molecular analyzes were used for mycobacterial strain isolation and characterization. Out of 50 samples, 24% tested positive by microscopy and 12% by culture. Molecular analysis identified 6 strains of Mycobacteria, exclusively Mycobacterium bovis specifically the subspecies bovis (Mycobacterium bovis subsp bovis). In conclusion, M. bovis subsp bovis is the primary agent responsible for bovine tuberculosis in Bobo-Dioulasso. Continuous monitoring of mycobacterial strains is therefore necessary for the effective control of this pathology in the local cattle population.展开更多
La0.7Sr0.3CoO3 (LSCO) thin films were epitaxially grown on (001)-single crystalline LaAlO3 substrates by metal organic deposition. The evolution of the crystallinity of the films having various thicknesses and obtaine...La0.7Sr0.3CoO3 (LSCO) thin films were epitaxially grown on (001)-single crystalline LaAlO3 substrates by metal organic deposition. The evolution of the crystallinity of the films having various thicknesses and obtained at various annealing temperatures is investigated using Raman spectroscopy. The Raman mode associated to the Jahn-Teller distortions in the LSCO films is found to be dependent on the annealing temperature and sensitive to the strain state evolution with film thickness. The microstructure and morphology of the obtained films were investigated using transmission electron microscopy observations on cross-sections and atomic force microscopy. The obtained films are characterized by nanocrystalline morphology, with an average roughness around 5 nm. By increasing the annealing temperature to 1000℃ and the film thickness to 100 nm, the electrical resistivity was decreased by several orders of magnitude. The film resistivity reaches approximately 2.7 × 10–4 Ω•cm in a wide interval of temperature of 77 - 320 K, making this material a promising candidate for a variety of applications.展开更多
Because the elderly account for 80% of deaths from COVID-19 and they may be more vulnerable to air pollution, in this retrospective study we aimed to explore individual and environmental risk factors for COVID-19 mort...Because the elderly account for 80% of deaths from COVID-19 and they may be more vulnerable to air pollution, in this retrospective study we aimed to explore individual and environmental risk factors for COVID-19 mortality in the geriatric departments of seven European University hospitals, between February and May 2020. Long-term exposure to air pollution was estimated through annual pollutant concentrations at the residential address over the last two years. Short-term variations in air pollutants and weather parameters were also examined through a 20-day period before the confirmed PCR diagnostic of COVID-19. We found positive associations for diabetes and COVID-19 mortality (OR 2.2 CI 95%: 1.1, 4.4). Regarding environmental factors, we found no association between COVID-19 mortality and air pollutants and weather parameters;however, our study suffers from strong disparities—such as patient characteristics—between fairly polluted and less polluted cities. In order to overcome those disparities between cities, we aimed to explore the relationship between air pollution and COVID-19 mortality within each city, but even with the high-efficiency modelisation systems, differences in air pollutants were too small to estimate the effect of air pollution at the city level. Thus, this study highlights the need to improve the estimation of individual exposure to air pollution. To address this issue, solutions exist such as the increase of the number of fixed air monitors, or even better, through the use of individual markers of air pollution exposure such as urinary black carbon or passive individual samplers. Furthermore, we underline that outdoor air pollutant concentrations may not be representative of individual exposure, especially in the elderly, thus, we suggest that further studies focus on indoor air pollution. Regarding meteorological conditions, we found no association between UV, temperature, wind speed and COVID-19 mortality. We found a positive association between an increase in relative humidity (RH) and COVID-19 mortality, however, the influence of RH on COVID-19 mortality remains unclear, and additional studies are needed to confirm this potential link.展开更多
Plants rely on a diverse set of small-molecule hormones to regu- late every aspect of their biological processes including develop- ment, growth, and adaptation. Since the discovery of the first plant hormone, auxin, ...Plants rely on a diverse set of small-molecule hormones to regu- late every aspect of their biological processes including develop- ment, growth, and adaptation. Since the discovery of the first plant hormone, auxin, hormones have always been at the frontier of plant biology.展开更多
文摘Introduction: The epidemiology of both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among drug users (DUs) is little known in West Africa. The study aimed to assess the prevalence of hepatitis B and C viruses among drug users in Burkina Faso. Methodology: This was a cross-sectional biological and behavioral survey conducted between June and August 2022, among drug users in Ouagadougou and Bobo Dioulasso, the two main cities of Burkina Faso. A respondent-driven sampling (RDS) was used to recruit drug users. Hepatitis B surface antigen was determined using lateral flow rapid test kits and antibodies to hepatitis C virus in serum determined using an Enzyme-Linked Immunosorbent Assay. Data were entered and analyzed using Stata 17 software. Weighted binary logistic regression was used to identify the associated factors of hepatitis B and C infections and a p-value Results: A total of 323 drug users were recruited with 97.5% males. The mean age was 32.7 years old. The inhaled or smoked mode was the most used by drug users. The adjusted hepatitis B and hepatitis C prevalence among study participants were 11.1% and 2.3% respectively. The marital status (p = 0.001), and the nationality (p = 0.011) were significantly associated with hepatitis B infection. The type of drug used was not significantly associated with hepatitis B infection or hepatitis C infection. Conclusion: The prevalence of HBsAg and anti-HCV antibodies among DUs are comparable to those reported in the general population in Burkina Faso. This result suggests that the main routes of contamination by HBV and HCV among DUs are similar to those in the population, and could be explained by the low use of the injectable route by DUs in Burkina Faso.
文摘Bovine tuberculosis (bTB) is an endemic zoonosis significantly affects animal health in Burkina Faso. The primary causative agent is Mycobacterium tuberculosis (M. tuberculosis) complex, mainly M. bovis. Cattle are considered as natural reservoir of M. bovis. However, in Burkina Faso, the circulation of these strains remains poorly understood and documented. This study aimed to identify and characterize Mycobacterium strains from suspected carcasses during routine meat inspection at Bobo-Dioulasso refrigerated slaughterhouse. A prospective cross-sectional study was conducted from January 2021 to December 2022 on cases of seizures linked to suspected bovine tuberculosis. Microbiological and molecular analyzes were used for mycobacterial strain isolation and characterization. Out of 50 samples, 24% tested positive by microscopy and 12% by culture. Molecular analysis identified 6 strains of Mycobacteria, exclusively Mycobacterium bovis specifically the subspecies bovis (Mycobacterium bovis subsp bovis). In conclusion, M. bovis subsp bovis is the primary agent responsible for bovine tuberculosis in Bobo-Dioulasso. Continuous monitoring of mycobacterial strains is therefore necessary for the effective control of this pathology in the local cattle population.
文摘La0.7Sr0.3CoO3 (LSCO) thin films were epitaxially grown on (001)-single crystalline LaAlO3 substrates by metal organic deposition. The evolution of the crystallinity of the films having various thicknesses and obtained at various annealing temperatures is investigated using Raman spectroscopy. The Raman mode associated to the Jahn-Teller distortions in the LSCO films is found to be dependent on the annealing temperature and sensitive to the strain state evolution with film thickness. The microstructure and morphology of the obtained films were investigated using transmission electron microscopy observations on cross-sections and atomic force microscopy. The obtained films are characterized by nanocrystalline morphology, with an average roughness around 5 nm. By increasing the annealing temperature to 1000℃ and the film thickness to 100 nm, the electrical resistivity was decreased by several orders of magnitude. The film resistivity reaches approximately 2.7 × 10–4 Ω•cm in a wide interval of temperature of 77 - 320 K, making this material a promising candidate for a variety of applications.
文摘Because the elderly account for 80% of deaths from COVID-19 and they may be more vulnerable to air pollution, in this retrospective study we aimed to explore individual and environmental risk factors for COVID-19 mortality in the geriatric departments of seven European University hospitals, between February and May 2020. Long-term exposure to air pollution was estimated through annual pollutant concentrations at the residential address over the last two years. Short-term variations in air pollutants and weather parameters were also examined through a 20-day period before the confirmed PCR diagnostic of COVID-19. We found positive associations for diabetes and COVID-19 mortality (OR 2.2 CI 95%: 1.1, 4.4). Regarding environmental factors, we found no association between COVID-19 mortality and air pollutants and weather parameters;however, our study suffers from strong disparities—such as patient characteristics—between fairly polluted and less polluted cities. In order to overcome those disparities between cities, we aimed to explore the relationship between air pollution and COVID-19 mortality within each city, but even with the high-efficiency modelisation systems, differences in air pollutants were too small to estimate the effect of air pollution at the city level. Thus, this study highlights the need to improve the estimation of individual exposure to air pollution. To address this issue, solutions exist such as the increase of the number of fixed air monitors, or even better, through the use of individual markers of air pollution exposure such as urinary black carbon or passive individual samplers. Furthermore, we underline that outdoor air pollutant concentrations may not be representative of individual exposure, especially in the elderly, thus, we suggest that further studies focus on indoor air pollution. Regarding meteorological conditions, we found no association between UV, temperature, wind speed and COVID-19 mortality. We found a positive association between an increase in relative humidity (RH) and COVID-19 mortality, however, the influence of RH on COVID-19 mortality remains unclear, and additional studies are needed to confirm this potential link.
文摘Plants rely on a diverse set of small-molecule hormones to regu- late every aspect of their biological processes including develop- ment, growth, and adaptation. Since the discovery of the first plant hormone, auxin, hormones have always been at the frontier of plant biology.
