It is widely recognized that the development of ZABs is impeded by the kinetic bottleneck of oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).The application of conformational entropy strategy to oxide...It is widely recognized that the development of ZABs is impeded by the kinetic bottleneck of oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).The application of conformational entropy strategy to oxides often involves introducing multiple elements with different properties,thereby providing outstanding bifunctional catalytic activity for OER/ORR.Nevertheless,the possible underlying catalytic pathways and potential interactions between various components are still poorly understood.This paper presents an excellent medium-entropy perovskite oxide,Sr(FeCoNiMo)_(1/4)O_(3−δ)(lower overpotential of 301 mV at 10 mA cm^(−2)).Zinc-air batteries employing it as a cathode catalyst demonstrate excellent round-trip efficiency(62%).By combining theoretical calculation with experiments,we aim to establish the link between the electronic structure of perovskite oxides with different elemental compositions and their OER mechanism.Research reveals that the conformational entropy strategy can simultaneously shift the O 2p-band center and metal d-band center of perovskite oxide towards the vicinity of the Fermi energy level,thereby triggering a more favorable lattice oxygen-participated mechanism(LOM)during the OER process.The outcomes of this work provide crucial insights into the role of conformational entropy strategies in oxygen catalysis and offer potential avenues for constructing efficient and stable electrocatalysts.展开更多
Introduction: Despite the rise of direct oral anticoagulants (DOACs), vitamin K antagonists (VKA) remain the most widely used oral anticoagulants in developing countries. The aim of this study was to estimate the prev...Introduction: Despite the rise of direct oral anticoagulants (DOACs), vitamin K antagonists (VKA) remain the most widely used oral anticoagulants in developing countries. The aim of this study was to estimate the prevalence of good anticoagulation in patients treated with VKA in Lomé and describe associated factors. Methods: This was a cross-sectional study conducted from November 2019 to October 2020 in the cardiology departments of two University teaching hospitals in Lomé (CHU Sylvanus Olympio and CHU Campus), involving patients on VKA for ≥3 months, with a target international normalized ratio (INR) of 2.5 and a therapeutic margin between 2 and 3. The quality of anticoagulation was assessed by the time in therapeutic range (TTR) which was assessed by the Rosendaal method. Good anticoagulation was defined by a TTR > 70%. Results: A total of 344 patients were included (mean age = 58 ± 13.8 years, women = 56.1%). Indications for VKA treatment were represented by venous thromboembolic disease (43.3%), supraventricular arrhythmia (28.2%), severe left ventricular systolic dysfunction (19.8%) and pulmonary hypertension (8.7%). The average TTR was 47.6 ± 20.8%. The rate of good anticoagulation was 17.7%. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol (OR = 11.17;95% CI: 3.2 - 39.6;p = 0.0002), concomitant low-dose aspirin (OR 4.44;95% CI: 1.4 - 13.9;p = 0.01) and INR monitoring exclusively by the patient himself (OR = 4.92;95% CI: 1.5 - 16.3;p = 0.008). The rate of thromboembolic and hemorrhagic complications was each 2.6% and was not correlated with the quality of anticoagulation. Quality of anticoagulation by VKAs was poor in our practice. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol, concomitant low-dose aspirin and monitoring of INR exclusively by the patient himself. Conclusion: The quality of oral anticoagulation by VKAs could be improved in our practice by the creation of anticoagulation clinics for better therapeutic education of patients and efficient management of VKA dose, and the use of prescription assistance software.展开更多
Aim: To describe the two-dimensional elastographic profile according to the Shearwave (2D-SWE) technique in patients with chronic liver disease in Lom. Materials and method: Cross-sectional, descriptive study conducte...Aim: To describe the two-dimensional elastographic profile according to the Shearwave (2D-SWE) technique in patients with chronic liver disease in Lom. Materials and method: Cross-sectional, descriptive study conducted over seven month at the Autel dElie Clinic in Lom, from January to August 2022, on adult patients with chronic liver disease who underwent abdominal ultrasound coupled with two-dimensional elastography. Results: The sample size was 54 patients. The mean age of the patients was 33 12 years, with extremes of 18 and 66 years. Patients aged 30 years or less accounted for 48.1% (n = 26). All patients (n = 54) had at least one transaminase assay with a mean of 69.3 78.3 IU/l (AST) and 59.3 82.8 IU/l (ALT). There was no statistically significant association between the biological parameters and the presence of fibrosis. Viral liver disease was the main cause, accounting for 81.5% (n = 44) of cases, with no significant association with the degree of fibrosis. Ultrasound revealed a dysmorphic liver (57.4%;n = 31) and portal hypertension (18.5%, n = 10). Fibrosis stages F1, F2 and F4 accounted for (48.1%, n = 26), (24.1%, n = 13) and (13%, n = 7) of cases respectively. Liver dysmorphia was significantly associated with the presence of fibrosis (p = 0.012) and portal hypertension was significantly associated with the degree of fibrosis (p = 0.0063). Conclusion: Assessment of liver fibrosis in patients with chronic liver disease using 2D-SWE elastography is essential for patient follow-up.展开更多
Background: Hemopathies were rarely observed in major sickle cell disease patients some thirty years ago, probably due to the high mortality rate among the latter as a result of progressive complications. Thanks to ad...Background: Hemopathies were rarely observed in major sickle cell disease patients some thirty years ago, probably due to the high mortality rate among the latter as a result of progressive complications. Thanks to advances in the management of sickle cell disease, patients' life expectancy has increased considerably, exposing them more frequently to neoplasia, including hematological malignancies. The increased risk of leukemogenesis is multifactorial and linked to the pathophysiological mechanisms of the clinical manifestations of sickle cell disease. Study Setting: The clinical haematology department of campus teaching hospital and the paediatric onco-haematology unit of Sylvanus Olympio teaching hospital in Lomé were used as study settings. Observations: Four hematologic malignancies were collected in a cohort of 5847 major sickle cell syndromes. The median age of the patients was 31.25 years (extremes: 14 and 58 years) and they were predominantly female (sex ratio M/F = 0.25). Two were on background therapy with hydroxyurea. Among the four patients, there were two cases of acute lymphocytic leukemia, including ALL3 in a 58-year-old SS woman and T-ALL2 in a 12-year-old SC. Then, a case of lymphocytic lymphoma in a 20-year-old SS man was reported and finally a case of chronic myelocytic leukemia in a 33-year-old woman of Sβ+ thalassaemia phenotype. Conclusion: To further report this coexistence, it is therefore essential to systematically consider hematological malignancies during major sickle cell syndromes even if there are similarities in the symptomatology of these two serious pathological situations.展开更多
The Lom Pangar dam, the largest reservoir in Cameroon with a storage capacity of 6 km3 and a 30 MW hydropower plant, primarily regulates the hydrologic regime of the Sanaga River to maintain hydropower efficiency duri...The Lom Pangar dam, the largest reservoir in Cameroon with a storage capacity of 6 km3 and a 30 MW hydropower plant, primarily regulates the hydrologic regime of the Sanaga River to maintain hydropower efficiency during dry seasons and enhance downstream hydropower plant performance. Understanding and managing sediments are crucial for the sustainability of dams, as indicated by numerous studies. This study assessed the granulometry of the sediments transported across the reservoir. For that purpose, 6 samples of fresh sediments were collected in the lacustrine and transitional sections of the reservoir using the standard method. Particles size was assessed using the laser diffusion technic after a 3 mm sieving. Various granulometric parameters were derived from the literature to analyze and characterize those sediments. Results show that silts are more than 70% of particles size and range between 2.19 - 60.26 µm. Size distribution also shows the same trend with D75 less than 51 µm. This is confirmed by the low values of Inman Skewness SkΦ (−0.168 to 0.303). The Sorting index S0 ranges from 0.31 to 0.53 µm, showing a very well-sorted sediments, aligning with low values of Krumbein index (0.906 - 1.683) that express the low heterometry of the particles. The consequence on the dam will be a quick clogging of the bottom of the reservoir. Their pH varies from 7.0 to 7.5. It also appears that the sandy fraction trend is higher in the right bank of the dam and reaches 22% on the right bank of Pangar River due to crystalline geology. Fraction greater than 3000 µm is negligible. The management of the dam has to keep attention to these results as siltation may close the safety outlet of the dam, damage turbines, and provoke recurrent technical and safety issues. Further, the clogging of the bottom of the reservoir may lead to an ecological problem with the limitation of hyporheic flow. Thus, water exchange with the underground water table and the natural purification of water reduce, while increasing sediments deposits change the biogeochemistry processes.展开更多
基金the financial support from the National Natural Science Foundation of China (51872067 and 21773048)
文摘It is widely recognized that the development of ZABs is impeded by the kinetic bottleneck of oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).The application of conformational entropy strategy to oxides often involves introducing multiple elements with different properties,thereby providing outstanding bifunctional catalytic activity for OER/ORR.Nevertheless,the possible underlying catalytic pathways and potential interactions between various components are still poorly understood.This paper presents an excellent medium-entropy perovskite oxide,Sr(FeCoNiMo)_(1/4)O_(3−δ)(lower overpotential of 301 mV at 10 mA cm^(−2)).Zinc-air batteries employing it as a cathode catalyst demonstrate excellent round-trip efficiency(62%).By combining theoretical calculation with experiments,we aim to establish the link between the electronic structure of perovskite oxides with different elemental compositions and their OER mechanism.Research reveals that the conformational entropy strategy can simultaneously shift the O 2p-band center and metal d-band center of perovskite oxide towards the vicinity of the Fermi energy level,thereby triggering a more favorable lattice oxygen-participated mechanism(LOM)during the OER process.The outcomes of this work provide crucial insights into the role of conformational entropy strategies in oxygen catalysis and offer potential avenues for constructing efficient and stable electrocatalysts.
文摘Introduction: Despite the rise of direct oral anticoagulants (DOACs), vitamin K antagonists (VKA) remain the most widely used oral anticoagulants in developing countries. The aim of this study was to estimate the prevalence of good anticoagulation in patients treated with VKA in Lomé and describe associated factors. Methods: This was a cross-sectional study conducted from November 2019 to October 2020 in the cardiology departments of two University teaching hospitals in Lomé (CHU Sylvanus Olympio and CHU Campus), involving patients on VKA for ≥3 months, with a target international normalized ratio (INR) of 2.5 and a therapeutic margin between 2 and 3. The quality of anticoagulation was assessed by the time in therapeutic range (TTR) which was assessed by the Rosendaal method. Good anticoagulation was defined by a TTR > 70%. Results: A total of 344 patients were included (mean age = 58 ± 13.8 years, women = 56.1%). Indications for VKA treatment were represented by venous thromboembolic disease (43.3%), supraventricular arrhythmia (28.2%), severe left ventricular systolic dysfunction (19.8%) and pulmonary hypertension (8.7%). The average TTR was 47.6 ± 20.8%. The rate of good anticoagulation was 17.7%. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol (OR = 11.17;95% CI: 3.2 - 39.6;p = 0.0002), concomitant low-dose aspirin (OR 4.44;95% CI: 1.4 - 13.9;p = 0.01) and INR monitoring exclusively by the patient himself (OR = 4.92;95% CI: 1.5 - 16.3;p = 0.008). The rate of thromboembolic and hemorrhagic complications was each 2.6% and was not correlated with the quality of anticoagulation. Quality of anticoagulation by VKAs was poor in our practice. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol, concomitant low-dose aspirin and monitoring of INR exclusively by the patient himself. Conclusion: The quality of oral anticoagulation by VKAs could be improved in our practice by the creation of anticoagulation clinics for better therapeutic education of patients and efficient management of VKA dose, and the use of prescription assistance software.
文摘Aim: To describe the two-dimensional elastographic profile according to the Shearwave (2D-SWE) technique in patients with chronic liver disease in Lom. Materials and method: Cross-sectional, descriptive study conducted over seven month at the Autel dElie Clinic in Lom, from January to August 2022, on adult patients with chronic liver disease who underwent abdominal ultrasound coupled with two-dimensional elastography. Results: The sample size was 54 patients. The mean age of the patients was 33 12 years, with extremes of 18 and 66 years. Patients aged 30 years or less accounted for 48.1% (n = 26). All patients (n = 54) had at least one transaminase assay with a mean of 69.3 78.3 IU/l (AST) and 59.3 82.8 IU/l (ALT). There was no statistically significant association between the biological parameters and the presence of fibrosis. Viral liver disease was the main cause, accounting for 81.5% (n = 44) of cases, with no significant association with the degree of fibrosis. Ultrasound revealed a dysmorphic liver (57.4%;n = 31) and portal hypertension (18.5%, n = 10). Fibrosis stages F1, F2 and F4 accounted for (48.1%, n = 26), (24.1%, n = 13) and (13%, n = 7) of cases respectively. Liver dysmorphia was significantly associated with the presence of fibrosis (p = 0.012) and portal hypertension was significantly associated with the degree of fibrosis (p = 0.0063). Conclusion: Assessment of liver fibrosis in patients with chronic liver disease using 2D-SWE elastography is essential for patient follow-up.
文摘Background: Hemopathies were rarely observed in major sickle cell disease patients some thirty years ago, probably due to the high mortality rate among the latter as a result of progressive complications. Thanks to advances in the management of sickle cell disease, patients' life expectancy has increased considerably, exposing them more frequently to neoplasia, including hematological malignancies. The increased risk of leukemogenesis is multifactorial and linked to the pathophysiological mechanisms of the clinical manifestations of sickle cell disease. Study Setting: The clinical haematology department of campus teaching hospital and the paediatric onco-haematology unit of Sylvanus Olympio teaching hospital in Lomé were used as study settings. Observations: Four hematologic malignancies were collected in a cohort of 5847 major sickle cell syndromes. The median age of the patients was 31.25 years (extremes: 14 and 58 years) and they were predominantly female (sex ratio M/F = 0.25). Two were on background therapy with hydroxyurea. Among the four patients, there were two cases of acute lymphocytic leukemia, including ALL3 in a 58-year-old SS woman and T-ALL2 in a 12-year-old SC. Then, a case of lymphocytic lymphoma in a 20-year-old SS man was reported and finally a case of chronic myelocytic leukemia in a 33-year-old woman of Sβ+ thalassaemia phenotype. Conclusion: To further report this coexistence, it is therefore essential to systematically consider hematological malignancies during major sickle cell syndromes even if there are similarities in the symptomatology of these two serious pathological situations.
文摘The Lom Pangar dam, the largest reservoir in Cameroon with a storage capacity of 6 km3 and a 30 MW hydropower plant, primarily regulates the hydrologic regime of the Sanaga River to maintain hydropower efficiency during dry seasons and enhance downstream hydropower plant performance. Understanding and managing sediments are crucial for the sustainability of dams, as indicated by numerous studies. This study assessed the granulometry of the sediments transported across the reservoir. For that purpose, 6 samples of fresh sediments were collected in the lacustrine and transitional sections of the reservoir using the standard method. Particles size was assessed using the laser diffusion technic after a 3 mm sieving. Various granulometric parameters were derived from the literature to analyze and characterize those sediments. Results show that silts are more than 70% of particles size and range between 2.19 - 60.26 µm. Size distribution also shows the same trend with D75 less than 51 µm. This is confirmed by the low values of Inman Skewness SkΦ (−0.168 to 0.303). The Sorting index S0 ranges from 0.31 to 0.53 µm, showing a very well-sorted sediments, aligning with low values of Krumbein index (0.906 - 1.683) that express the low heterometry of the particles. The consequence on the dam will be a quick clogging of the bottom of the reservoir. Their pH varies from 7.0 to 7.5. It also appears that the sandy fraction trend is higher in the right bank of the dam and reaches 22% on the right bank of Pangar River due to crystalline geology. Fraction greater than 3000 µm is negligible. The management of the dam has to keep attention to these results as siltation may close the safety outlet of the dam, damage turbines, and provoke recurrent technical and safety issues. Further, the clogging of the bottom of the reservoir may lead to an ecological problem with the limitation of hyporheic flow. Thus, water exchange with the underground water table and the natural purification of water reduce, while increasing sediments deposits change the biogeochemistry processes.
