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Peculiar chemical, mechanical, and magnetic properties make cobalt a key metal for a variety of “hot” applications like the cathode production of Li-ion batteries. Cobalt is also the preferred metallic binder for tungsten carbide tool manufacturing. The recent increasing criticality of cobalt and tungsten is driving the interest of manufacturers and researchers toward high-rate recycling of hard-metal (HM) waste for limiting the demand for raw materials. A simple and environmentally friendly hydrometallurgical route for Co-selective dissolution from HM wastes was developed by using weak, bio-derived, and biodegradable organic acids (OAs). In this study, OAs, namely, acetic (HAc), citric (H3Cit), maleic (H2Mal), lactic (HLac), succinic (H2Suc), lactobionic (HLB), and itaconic (H2It) acids, were selected for their pKa1 values spanning from 1.8 to 4.7 and systematically tested as selective cobalt leaching agents from WC-Co-based wastes in water, isolating the formed complexes in the solid state. Thereby, all of them seemed to be efficient in selective Co leaching, achieving almost quantitative Co dissolution from HM by-products still at low concentration levels and room conditions in a short time, leaving the residual WC unreacted and ready to be re-employed for industrial purposes. Nevertheless, two main categories of organic acids were distinguished depending on their oxidizing/complexing behavior: class 1 OAs, where the metal oxidation is carried out by H+, and class 2 OAs, where oxidation is carried out by an external oxidant like O2. A combined experimental/theoretical investigation is described here to show the reasons behind this peculiar behavior and lay the foundation for a wider discussion on the leaching capabilities of OAs toward elemental metals. Due to the demonstrated effectiveness, low cost, eco-friendliness, and large availability through biotechnological fermentative processes, particular attention is devoted here to the use of HLac in hydrometallurgy as an example of class 2 OA. WC-Co materials recovered by HLac mild hydrometallurgy demonstrated a metallurgical quality suitable for re-employment in the HM manufacturing process.

The purpose of this paper is to analyze the effects of repeated floods in the city of Niamey and the strategies developed by the state in terms of prevention, rehabilitation, and care for victims. Although numerous framework documents have been drafted in the last decade and urbanization in flood zones has been limited, the reality in Niamey shows that urban sprawl is increasing along the riverbank and the population facing vulnerable situations is growing. The inefficiency of state action determines that, on the one hand, it is non-governmental institutions that need to develop improvement plans—with the recovery of the city being dependent on the arrival of their funds and their distribution in those areas that donor countries consider most suitable—and on the other hand, it is the citizens—already vulnerable—who must find their own resilience mechanisms to try to survive the next flood. This study reveals that this diversity of players is involved in flood management through emergency relief, solidarity in rehousing, and providing support for living and non-living flood victims. Despite this mobilization, the actions undertaken are hampered by a number of constraints. Insufficient financial and human resources, a lack of foresight on the part of the authorities, and poorly coordinated actions are the main difficulties limiting the success of public action in the face of flooding. Through a qualitative approach, combining documentary research, direct observation and semi-structured interviews, we analyze the mobilization of actors around the management of the effects of floods in Niamey.

Background: To end the COVID-19 pandemic, a large part of the world must be immune to the virus by vaccination. Therefore, this study aimed to gauge intent to be vaccinated against COVID-19 among ordinary people and to identify attitudes towards vaccines and barriers for vaccine acceptance. Methods: The study population comprises 1880 people residing in different countries that answer a prepared questionnaire. The questionnaire topics are demographics, historical issues, participants’ attitudes and beliefs regarding vaccines, concerns, and vaccine hesitancy. Results: Attitudes and beliefs relating to vaccines in general, and the COVID-19 vaccine, were ascertained. Overall, 66.81% of the contributors would like to be vaccinated against COVID-19, while %33.19 did not intend to be vaccinated. Reasons for COVID-19 vaccine hesitancy included concern regarding vaccine side effects, fear of getting sick from the uptake of the vaccine, and the absence of accurate vaccine promotion news. Individuals with higher education believe that India (68.6%) produces the best vaccine (P

Coronavirus disease 2019 (COVID-19) dissemination occurred from December 2019 and quickly spread to all countries. Infected patients with COVID-19 have had a wide range of symptoms, ranging from mild to severe illness. The most mortality was observed in patients with underlying disease and over 45 years. World statistics have shown that the COVID-19 outbreak is most expanded in Middle Eastern, West Asian, European, North, and South American countries, and is least expanded in African countries. Therefore, the aim of the paper was the evaluation of six African countries including Mali, Mauritania, Niger, Guinea, Togo, and Djibouti to find why this disease is least expanded in African countries. Study was conducted by Questioner for countries health organizers to define their different aspect exposure and fight with COVID-19 including epidemiology, clinical aspects of the disease, case definitions, diagnosis laboratory confirmation, and referral of cases by the portal of entry, case management, and disease prevention in these countries. According to this opinion review, due to the low international flights and low domestic travel, the spread, and prevalence of COVID-19 was low and the return of the immigrants of these countries has caused the spread of COVID-19 among these countries. Experience, preparation, and impact of previous infections epidemic such as the Ebola virus epidemic would have beneficial, which have promoted certain reflexes among people that cause low dissemination in these countries.

Copyright of Mali Médical is the property of Mali Medical, Faculte de Medecine, de Pharmacie et d'Odonto-stomatologie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pan African Medical Journal is the property of Pan African Medical Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Médecine et Santé Tropicales is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This manuscript is about the electric output of the silicon (Si) photovoltaic (PV) cell versus the electromagnetic field of a radio wave and a monochromatic illumination in three-dimensional (3D) assumptions. The polarisation direction of the electromagnetic wave and power density are fixed. The electromagnetic wave is provided by electromagnetic emission sources such as the telecommunication, radio, or TV antennas. A PV system is installed in the vicinity of an electromagnetic emission source. The current produced by the PV cell is sensitive to electromagnetic field increase more than the electric voltage. The electromagnetic field causes the decomposition of the current into two components which are a transferred current and a leakage current. The transferred component provides the transmitted current to the external load while the leakage component gives the loss of the carrier charge into the junction. Consequently, this decomposition of the current shares the electric power in transferred electric power and leakage electric power. The transferred electric power is obtained only in the intermediate circuit, and the maximum power point (MPP) shifts to the short circuit situation as the junction dynamic velocity becomes the greatest. However, the leakage electric power corresponds to a loss of the minority carrier’s charge in the junction during the crossing of the junction. This loss causes a Joule heating effect of the junction. The heating of the junction causes the quality degradation of the PV cell mainly due to the electric component. The solar illumination wavelength is presenting the inversion phenomenon with the maximum of the electrical outputs of the silicon PV cell of around 0.70 μm which provides the greatest conversion efficiency. This value has been chosen for the modelling of the radio wave influence. Hence, the conversion efficiency increases when the PV system is far away from the electromagnetic emission source. PV system installation in the vicinity of an electromagnetic emission source is not advised.

Aim of Study: To describe the clinical, therapeutic and evolutionary profile of patients followed for rifampicin-resistant pulmonary tuberculosis (RR-TB) at the Regional Hospital Centre (RHC) of Maradi (Niger) from 2014 to 2018., Methods: We conducted a retrospective and descriptive study based on the records of patients followed for Multidrug-resistant tuberculosis (MDR-TB) between January 1, 2014 and June 30, 2018 at the resistant tuberculosis management unit in Maradi (Niger). This unit is located within the RHC of Maradi and has a capacity of 20 beds in 4 wards. It receives patients with tuberculosis resistant to first-line anti-tuberculosis drugs. In this study, patients diagnosed with RR-TB by genotypic (GeneXpert MTB/RIF) or phenotypic (culture) testing were included. We excluded from this study: patients previously treated for more than 1 month with second-line anti-TB drugs; patients with resistance to second-line injectables (SLI) and/or fluoroquinolones (FQ); patients with an electrocardiogram QTc greater than 500 ms (the corrected QT (QTc) estimates the QT interval at a rate of 60 beats per second); cases of atypical mycobacteriosis detected by phenotypic testing.Patients were previously on 2RHZE/4RH prior to the discovery of resistance. The treatment protocol for resistant TB was as follows: 4KmMfxPtoCfzHZE/5MfxCfzZE (The second-line injectable was replaced by Lzd in case of initial or treatment-emergent deafness). HIV co-infected patients received, in addition to anti-tuberculosis drugs, antiretrovirals and cotrimoxazole in preventive doses., Results: A total of 80 patients were included in the present study (70 males and 10 females, mean age 34.4 years with extremes ranging from 18 to 71 years). Patients aged 18-35 years accounted for more than half. Patients with primary treatment failure were the most frequent type (36%) followed by patients with retreatment failure (24%) and patients with retreatment relapse (17%). It should be noted that 77 patients (96%) were previously treated for TB and only 3 patients (4%) were new cases. The majority of patients (70%) had a Body mass index of less than 18 kg/m 2 . 7.5% of patients were HIV positive, one was diabetic, 52% of the patients had grade 2 radiological lesions. Grade 1 deafness was noted at the beginning of treatment in 3%. A third of patients (36%) were primary treatment failures. The treatment protocol was as follows: 4KmMfxPtoCfzHZE/5MfxCfzZE. Only 1 patient had a positive culture at the end of the 4th month of treatment. Most of the patients had experienced adverse events, mainly digestive, with vomiting being the most common. The therapeutic success rate was 88%. We noted 10% of deaths, 1% of therapeutic failure and 1% of lost to follow-up.Six months after treatment, 48 patients (60%) were smear negative and 43 (54%) were culture negative. In 32 patients (40%), the smear was not performed and culture was not performed in 37., Conclusion: The short treatment regime gives satisfactory results in the absence of resistance to fluoroquinolones, with rare adverse effects. In Niger, further efforts should be made to minimize the delay in diagnosis which is responsible for most deaths during treatment. A centre could usefully be designated to organize "TB consiliums" allowing any practitioner to submit difficult cases of MDR-TB., (Copyright © 2023 SFMTSI.)

Objective: Objective of this study was to determine the frequency of tuberculosis (TB) and the impact of immunosuppression in patients living with HIV (PvVIH) monitored at the Regional Hospital Center (CHR) of Maradi., Methods: That was a retrospective study based on the medical records of PvVIH followed in the infectious diseases department of the CHR of Maradi. All HIV-positive adults were included in regular consultations between January 2013 and September 2018., Results: A total of 872 patients were included. The average age of the cohort was 36.10 years ± 11,53. Of these patients, 15 had tuberculosis infection with a frequency of 1.72% (95% CI: 1.05 - 2.82) and 429 a CD4 T cell count of less than 200 / mm3. Of the 15 co-infected HIV / TB patients, 60% had a CD4 T cell count of less than 200 / mm3 (p = 0.78). HIV1 was tested in 98.73% of cases, HIV2 in 0.69% and both types of virus in 0.58% of cases. All patients who had a TB infection were HIV1 +., Conclusion: Knowledge about the prevalence and impact of TB in people living with HIV is needed to establish a mechanism for controlling this disease. It is more than necessary to prevent TB among PLWHIV when CD4 counts begin to decline., (Le comité de rédaction se réserve le droit de renvoyer aux auteurs avant toute soumission à l'avis des lecteurs les manuscrits qui ne seraient pas conformes à ces modalités de présentation. En outre il leur conseille de conserver un exemplaire du manuscrit, des figures et des tableaux.)

Introduction: This study aimed to describe the epidemiological, clinical and evolutionary profile of patients treated for tuberculosis at the Regional Hospital of Maradi., Methods: We conducted a retrospective, descriptive and analytical study of data from the medical records of patients treated for tuberculosis from 1 st January 2015 to 31 st December 2017., Results: A total of 595 patients were followed (406 men, 68.24%, and 189 women, 31.76%) with a prevalence of 27,71%. The average age of patients was 42.3 ranging from 13 months to 85 years; 70.5% of these patients were from urban areas. Merchants represented 36.9% of the cases. Bacterial test was positive in 64.7% of cases. Functional signs included: coughing (99.5%), fever (79.5%), and chest pain. Pulmonary tuberculosis represented 78.7% of cases. Therapy was effective in 81.28% of cases. HIV prevalence was 13.6%, lethality 10.42% (40.4% of patients died from TB/HIV co-infection)., Conclusion: Tuberculosis is a scourge in low-income countries, with 10.42% of deaths. HIV/AIDS infection has negatively contributed to these deaths during the study period. The search for comorbidities in any patient with tuberculosis should be systematic in order to improve their global management., Competing Interests: Les auteurs ne déclarent aucun conflit d'intérêts.

Objective: The present study aimed to determine the seroprevalence of HBs Ag in HIV-infected patients followed at the Maradi CHR., Methods: This is a retrospective study based on the records of the infectious diseases department of the CHR of Maradi. Included were all HIV-positive adults seen in consultation who received HBs Ag research between 2006 and 2018. The data was collected from patients' medical records., Results: In total, 2770 patients included in our study. The average age of the cohort was 38 years old. Of these patients, 159 had HBs Ag or a prevalence of 5.74% (95% CI: 4.93 - 6.67). HIV-HBV coinfections were higher in men (52.20%). HIV1 subtype was involved in 96.86% of cases. Two patients co-infected with HIV-HBV had HIV1 and HIV2 dual profile. Which represents 1.26% (95% CI: 0.15 - 4.47)., Conclusion: This study confirms the high prevalence rate of HBV coinfection in HIV-infected patients. It is therefore necessary to screen all HIV-infected patients for better management., (Le comitée de rédaction se réserve le droit de revoyer aux auteurs avant toute soumission à l'avis des lecteurs les manuscrits qui ne seraient pas conformes à ces modalités de présentation. En outre il leur conseille de sonserver un examplaire du manuscrit, des figures et des tableaux.)