Tuning the electronic structure of graphene by ion irradiation

Mechanically exfoliated graphene layers deposited on SiO2 substrate were irradiated with Ar+ ions in order to experimentally study the effect of atomic scale defects and disorder on the low-energy electronic structure of graphene. The irradiated samples were investigated by scanning tunneling microscopy and spectroscopy measurements, which reveal that defect sites, besides acting as scattering centers for electrons through local modification of the on-site potential, also induce disorder in the hopping amplitudes. The most important consequence of the induced disorder is the substantial reduction in the Fermi velocity, revealed by bias-dependent imaging of electron-density oscillations observed near defect sites

Savoirs techniques locaux, sources d'innovations ? Production de savoirs actionnables dans une démarche de recherche action en partenariat

International audienceFace aux défis auxquels l'Afrique de l'Ouest est confrontée pour son développement, les savoirs techniques locaux peuvent-ils être des sources de connaissance pour l'innovation ? Traditionnellement, les pratiques d'un groupe social sont réglées sur un long terme par les savoirs locaux jusqu'à l'avènement de problèmes inhabituels. Dans chaque nouvelle situation problématique, le retour à la maîtrise technique passe par l'acquisition de nouveaux savoirs et l'apprentissage de nouvelles pratiques, le tout s'inscrivant dans un processus d'innovation. Les démarches de recherche action en partenariat, visant à résoudre les problèmes vécus par les acteurs de terrain, requièrent la production de références actionnable. Dans ce cadre, les savoirs techniques locaux peuvent favoriser l'innovation s'ils sont réellement pris en compte. Nous proposons que dans les diagnostics, ils soient intégrés dans l'analyse des pratiques et de leurs fondements, et que dans la mise en œuvre des solutions et la conception des innovations, ils soient coalisés aux savoirs exogènes mobilisés. Cette thèse sera illustrée par des travaux de recherche en partenariat conduits, dans les villages de Koumbia et de Waly (ouest du Burkina Faso) visant la conception et la mise en œuvre d'innovations sur les pratiques de conduite des troupeaux au pâturage (élaboration de nouvelles règles) et de gestion de la fertilité des sols avec des fumures organiques (diversification et amélioration de la production)

Setting-up nurse-led pilot clinics for the management of non-communicable diseases at primary health care level in resource-limited settings of Africa

Background: This article describes the setting-up process for nurse-led pilot clinics for the management of four chronic diseases: asthma, type 2 diabetes mellitus, epilepsy and hypertension at the primary health care level in urban and rural Cameroon. Methods: The Biyem-Assi urban and the Bafut rural health districts in Cameroon served as settings for this study. International and local guidelines were identified and adapted to the country’s circumstances. Training and follow-up tools were developed and nurses trained by experienced physicians in the management of the four conditions. Basic diagnostic and follow-up materials were provided and relevant essential drugs made available. Results: Forty six nurses attended six training courses. By the second year of activity, three and four clinics were operational in the urban and the rural areas respectively. By then, 925 patients had been registered in the clinics. This represented a 68.5% increase from the first year. While the rural clinics relied mainly on essential drugs for their prescriptions, a prescription pattern combining generic and proprietary drugs was observed in the urban clinics. Conclusion: In the quest for cost-effective health care for NCD in sub-Saharan Africa, rethinking health workforce and service delivery has relevance. Nurse-led clinics, algorithm driven service delivery stands as alternatives to overcome the shortage of trained physicians and other issues relating to access to care

Зональные фораминиферовые схемы нижнего карбона западных регионов Украины

Запропоновано зональні форамініферові схеми нижнього карбону Придобруджинського прогину та Львівсько-Волинського басейну. У Придобруджинському прогині нараховується вісім зон і дві підзони, з них одна зона і дві підзони виділені вперше. У п'яти зон змінено види-індекси, У Львівсько-Волинському басейні є п’ять зон і дві підзони, з них одна зона нова. Дві колишні зони об'єднано в одну — з двома підзонами. Змінено види-індекси трьох зон. В обох регіонах уточнено обсяг зон та їх межі. Границі зон і підзон проведено за першою появою видів-індексів. Проведено зіставлення цих зональних схем із форамініферовими зонами Доно-Дніпровського регіону і Східно-Європейської платформи.Foraminiferal zonal schemes of the Lower Carboniferous of the Dobrudja Foredeep and Lvov-Volynian basin are proposed in the paper. The first scheme includes eight zones and two subzones; among them one zone and two subzones are specified for the first time. In five zones species-index is changed. The second scheme includes five zones and two subzones; one zone is specified for the first time. Two preceding zones are united into one with two subzones. In three zones species-index is changed. The boundaries of zones and subzones are determined according to the first occurrence of species-index. Correlation of these zones with foraminiferal zones of Dono-Dnieper region and East-European platform is performed

Antifungal potential of essential oils, aqueous and ethanol extracts of thirteen plants against Fusarium oxysporum f . sp Lycopersici and Phytophtora infestans (Mont.) de Bary as major tomato pathogens

Antifungal activity of essential oils (EO), ethanol extracts (ETE) and cold water extracts (CWE) of thirteen plants was evaluated against Fusarium oxysporum and Phytophtora infestans causal agents of tomato Fusarium wilt and late blight diseases respectively. The supplemented media and slide germination techniques were carried out to determine the effect of extracts on the mycelial growth and conidia germination of pathogens. The results showed that essential oils exhibited the highest antifungal activity followed by ETE and CWE. Callistemon citrinus, Cymbopogon citratus and Ocimum gratissimum essential oils were the most active inhibiting completely radial growth and conidia germination of Phytophtora infestans at 312.5 and 625 µg/ml. Essential oils of Ocimum gratissimum and Cymbopogon citratus inhibited totally the radial growth and conidia germination of Fusarium oxysporum at 625 and 312.5 µg/ml respectively. ETE of Ageratum conyzoides and Callistemon citrinus were the most active inhibiting radial growth of Phytophtora infestans. Cymbopogon citratus and Ocimum gratissimum were the most active against radial growth and conidia germination of Fusarium oxysporum at 6250 µg/ml. The fungi toxic potential of some extracts was comparable to synthetic fungicides used as positive controls. Preliminary phytochemical analysis of ETE and CWE revealed that stronger inhibiting effects were recorded with extracts rich in phenols, flavonoids, tannins, and coumarins. These findings may contribute to develop new green fungicides to protect tomato from Fusarium wilt and late blight diseases

The Floor Stiffness Effect on Vulnerability Assessments and Intervention Designs of Historic Buildings: the Case Study of the “Procuratie Vecchie” in Venice, Italy

In the Italian seismic scenario, and beyond, interventions on existing buildings focused on the evaluation and reduction of seismic risk of cultural heritage have gained more and more importance in the engineering field. Therefore, for the designer it becomes increasingly useful to have a methodology that allows to carry out, in the study of an existing structure behavior, the vulnerability assessment of both the actual state and the design state, evaluating the adequacy of potential intervention of seismic improvement. In this paper some phases of this methodology are presented in the context of the restoration work started in November 2017, and currently in progress, of the historical building of Procuratie Vecchie in Piazza San Marco in Venice, with particular focus on the consolidation intervention of the timber floors which satisfy the conservation requirements imposed by the Superintendence of Venice. Actually, the influence of floor diaphragms on structural behavior of existing masonry building subjected to seismic action is critically discussed with particular reference to the effects of in-plane stiffness of floors on the seismic distribution of forces on lateral walls and on the out–of–plane mechanism of the walls

Neural Stem Cell-Derived Small Extracellular Vesicles: key Players in Ischemic Stroke Therapy – A Comprehensive Literature Review

Zhihan Zhu,1,* Qiankun Zhang,1,* Jia Feng,1 Sonia Zebaze Dongmo,1 Qianqian Zhang,1 Songze Huang,1 Xiaowen Liu,1 Guilong Zhang,2 Lukui Chen1 1Department of Neurosurgery, Southern Medical University Hospital of Integrated Traditional Chinese and Western Medicine, Southern Medical University, Guangzhou, Guangdong Province, People’s Republic of China; 2Department of Neurosurgery, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Lukui Chen, Department of Neurosurgery, Southern Medical University Hospital of Integrated Traditional Chinese and Western Medicine, Southern Medical University, Guangzhou, People’s Republic of China, Email [email protected] Guilong Zhang, Department of Neurosurgery, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China, Email [email protected]: Ischemic stroke, being a prominent contributor to global disability and mortality, lacks an efficacious therapeutic approach in current clinical settings. Neural stem cells (NSCs) are a type of stem cell that are only found inside the nervous system. These cells can differentiate into various kinds of cells, potentially regenerating or restoring neural networks within areas of the brain that have been destroyed. This review begins by providing an introduction to the existing therapeutic approaches for ischemic stroke, followed by an examination of the promise and limits associated with the utilization of NSCs for the treatment of ischemic stroke. Subsequently, a comprehensive overview was conducted to synthesize the existing literature on the underlying processes of neural stem cell-derived small extracellular vesicles (NSC-sEVs) transplantation therapy in the context of ischemic stroke. These mechanisms encompass neuroprotection, inflammatory response suppression, and endogenous nerve and vascular regeneration facilitation. Nevertheless, the clinical translation of NSC-sEVs is hindered by challenges such as inadequate targeting efficacy and insufficient content loading. In light of these limitations, we have compiled an overview of the advancements in utilizing modified NSC-sEVs for treating ischemic stroke based on current methods of extracellular vesicle modification. In conclusion, examining NSC-sEVs-based therapeutic approaches is anticipated to be prominent in both fundamental and applied investigations about ischemic stroke.Keywords: neural stem cells, small extracellular vesicles, ischemic stroke, neuroprotection, neural regeneratio

Macrofilaricidal Activity after Doxycycline Only Treatment of Onchocerca volvulus in an Area of Loa loa Co-Endemicity: A Randomized Controlled Trial

The control of onchocerciasis in Africa relies on the sustained delivery of ivermectin. In certain areas, annual treatments delivered with high population coverage for at least 15–17 years can break transmission. In other endemic settings this strategy alone is thought to be insufficient to eradicate the disease. One of the major limitations occurs in areas that are co-endemic with another filarial infection caused by Loa loa, due to the risk of a rare severe adverse event associated with the rapid killing of L. loa microfilariae in heavily parasitized individuals. There are also concerns over recent evidence of reduced efficacy of ivermectin and the possible development of resistance. An alternative approach is to target the Wolbachia bacterial endosymbionts of Onchocerca volvulus with the antibiotic, doxycycline. In an area of Cameroon co-endemic for onchocerciasis and loiasis we conducted a trial comparing doxycycline with or without ivermectin treatment to ivermectin treatment alone. A six-week course of doxycycline delivers macrofilaricidal and sterilizing activities, which is not dependent upon co-administration of ivermectin. Doxycycline is well tolerated in patients co-infected with moderate intensities of L. loa microfilariae. The trial indicates that anti-wolbachial therapy is a feasible alternative to ivermectin in communities co-endemic for onchocerciasis and loiasis

The Disease Burden of Taenia solium Cysticercosis in Cameroon

Taenia solium cysticercosis is a zoonotic disease occurring in many developing countries. A relatively high prevalence in humans and pigs has been reported in several parts of the world, but insufficient data are available on the disease burden. Disease impact assessment needs detailed information on well-defined epidemiological and economic parameters. Our work conducted in West Cameroon over several years allowed us to collect the necessary information to estimate the impact of the parasite on the human and animal populations in this area using both cost and Disability Adjusted Life Year (DALY) estimations. This study identified the professional inactivity caused by the disease as the major loss factor in comparison to the cost of health care and losses due to infected pigs. These findings should allow a simpler estimation of the global disease burden based on information on salary levels and human cysticercosis prevalence in endemic areas of the world. In addition, the number of DALYs lost was higher than estimates already available for some other neglected tropical diseases in sub-Saharan Africa

Mapping of Schistosomiasis and Soil-Transmitted Helminthiasis in the Regions of Centre, East and West Cameroon

Schistosomiasis and soil-transmitted helminthiasis (STH) are a major public health problem in Cameroon. The national control strategy of these diseases was based on historical data collected 25 years ago, which might be outdated in some situations due to several factors including control activities, improved or degraded sanitation and hygiene, socio-economic improvement and disease transmission dynamics. To help planning, improving control strategies and evaluation of control activities, there was a need to update the distribution of schistosomiasis and STH. We conducted parasitological surveys in three regions of Cameroon, i.e. Centre, East and West. Our results showed a significant decrease of STH infection prevalence and intensities in all these three regions, in comparison to previous mapping data, with an overall decline of prevalence from 81.1–93% to 10.5–46.6%. These results show the positive impact of annual deworming campaigns, and illustrate the progressive success of the national programme for the control of schistosomiasis and STH in Cameroon. Furthermore, our results showed an increase of the number of high transmission foci of schistosomiasis, and allowed identifying new health districts requiring mass treatment with praziquantel, and those where deworming should be reinforced