Synthesis and characterization of dense, rare-earth based high entropy fluorite thin films

High entropy oxides (HEOs) with 5 or more cations in equimolar proportions that result in a phase-pure material, are a new class of materials attracting a lot of attention in recent years. HEOs exhibit interesting optical, electrochemical, magnetic and catalytic properties. To get a comprehensive understanding of the physics behind the complex interactions taking place in these materials, it is important to evaluate the material in (near-fully) dense forms, such as pellets or thin films. The fluorite structured high entropy oxide, (CeLaSmPrY)O2−x has been investigated only in the powder form and there are no studies on the dense form of fluorite (CeLaSmPrY)O2−x. One of the main reasons is that (CeLaSmPrY)O2−x undergoes a structural transition from fluorite to bixbyite (at 1000 °C) and typically temperatures above the transition (>1200 °C) are required for achieving high densities via conventional sintering. In this study, we synthesize dense films of fluorite structured (CeLaSmPrY)O2−x by sol-gel as well as pulsed laser deposition processes. The films synthesized via sol-gel process exhibit equiaxed grains and polycrystalline morphology, whereas columnar and epitaxial films are obtained using pulsed laser deposition. Thus, microstructural tuning of dense fluorite (CeLaSmPrY)O2−x films has been demonstrated while maintaining the basic characteristics of the HEO as observed in the powder form, therefore, paving the way towards more comprehensive studies for possible applications

Incidence of Hortaea werneckii in a tertiary care centre in Maharashtra

Background: Hortaea werneckii, a melanized yeast-like fungus is the cause of Tinea nigra, a superficial dermatomycosis. The lesions are differential diagnosis of melanocytic lesions. Tinea nigra mainly affects people in the temperate or subtropical climates with well-demarcated, expanding, hyperchromic plaques on the palms or soles. Methods: Skin scrapings from various lesions with suspected fungal aetiology were received after clinical assessment and were subjected to laboratory procedures, including direct KOH (10%) analysis, culture on Sabouraud dextrose agar (SDA), and incubation at 25°C and 37°C for 28 days which was further confirmed by lactophenol cotton blue preparation and slide culture. Results: Out of 295 samples examined, a total number of 15 samples were positive for Hortaea werneckii in the time period of 1st January 2023 to 31st December 2023. 7 patients had lesions on both palmar as well as plantar region (46.66%), 3 on palmar and plantar region each (20%), 1 (6.66%) on scalp and 1 (6.66%) on face and scalp. The skin scrapings were taken and examined in 10% KOH wet mount which showed positivity of 11 (73.33%) samples. The primary isolation of the fungus was done on SDA. Conclusions: Hortaea werneckii is the most common cause of Tinea nigra. Pigmented patches of Tinea nigra may be confused with other inflammatory or neoplastic aetiology. For Tinea nigra, skin scrapings are sufficient for diagnosis by KOH mount and culture on SDA. Generally, the lesions resolve within 2 weeks of adequate treatment. To conclude, a high suspicion should be maintained to timely diagnose the disease, avoid unnecessary invasive investigation and early administration of treatment

Facteurs Explicatifs de la Pratique Contraceptive Moderne des Femmes Fréquentant les Formations Sanitaires du District de Youwarou au Mali

Objectif : Mettre en exergue les déterminants de la pratique contraceptive moderne des femmes fréquentant les centres de santé du district de Youwarou au Mali. L’étude part du constat que la situation sanitaire est non satisfaisante avec un faible taux de fréquentation des centres de santé qui est de 15 %, exacerbée par la crise sécuritaire déclenchée en 2012. Ainsi, le taux d’utilisation des méthodes contraceptives modernes est également très faible soit 1,07%. En effet, l’utilisation de la contraception moderne selon la cinquième Enquête Démographique et de Santé du Mali (EDSM-5) est de 9,6% au niveau national et de 2,7% dans la région de Mopti. Méthode : Etude transversale quantitative dont l’enquête fut réalisée du 1er mai au 30 juin 2015, et a porté sur 200 femmes âgées de 15-49 ans fréquentant les 07 centres de santé dans le district de Youwarou. Les données collectées par un questionnaire ont été vérifiées, compilées à l’aide du logiciel le Sphinx Plus² version 4.5, puis transférées sur le logiciel stata 10 pour l’analyse statistique. Pour l’analyse des données, nous avons eu recours à deux méthodes dans ce travail : la méthode d’analyse descriptive (analyse bivariée) et la méthode d’analyse explicative (analyse multivariée). Résultats : L’étude montrent que la prévalence contraceptive moderne est de 8,8%. Les femmes de centre de Guidio-sare utilisent les contraceptives modernes plus que leurs consoeurs du district. Enfin les déterminants de la pratique contraceptive sont notamment l’ethnie, l’âge et le statut matrimonial de la femme. Conclusion : A la lumière de cette étude, nous suggérons qu’un accent particulier doit être mis sur les déterminants révélés afin de promouvoir les méthodes contraceptives modernes. Objective: Highlight the determinants of modern contraceptive practice among women attending health centers in the Youwarou health district of Mali. The study was carried out based on the observation that the health situation is unsatisfactory with a low utilization rate of health centers is 15%, exacerbated by the security crisis triggered in 2012. Thus, the rate of use of modern contraceptive methods is also very low is 1.07%. Indeed, the use of modern contraception according to the fifth Demographic and Health Survey of Mali (EDSM-5) is 9.6% at the national level and 2.7% in the Mopti region. Methods: A quantitative cross-sectional study was carried out from May 1th to June 30th 2015, and covered 200 women aged 15-49 attending the 07 health centers in the district of Youwarou. The data collected by a questionnaire was verified, compiled using the software Sphinx Plus² version 4.5, and then transferred to the Stata 10 software for statistical analysis. For data analysis, two methods were used in this work: the descriptive analysis method (bivariate analysis) and the explanatory analysis method (multivariate analysis). Results: The study shows that modern contraceptive prevalence is 8.8%. women of Guidio-sare Center use modern contraceptives more than their sisters of district. Finally, the determinants of contraceptive practice include the ethnicity, age and marital status of women. Conclusion: In the light of this study, we suggest that emphasis should be placed on the identified determinants in order to promote modern contraceptive methods

Phase–Property Diagrams for Multicomponent Oxide Systems toward Materials Libraries

Exploring the vast compositional space offered by multicomponent systems or high entropy materials using the traditional route of materials discovery, one experiment at a time, is prohibitive in terms of cost and required time. Consequently, the development of high-throughput experimental methods, aided by machine learning and theoretical predictions will facilitate the search for multicomponent materials in their compositional variety. In this study, high entropy oxides are fabricated and characterized using automated high-throughput techniques. For intuitive visualization, a graphical phase–property diagram correlating the crystal structure, the chemical composition, and the band gap are introduced. Interpretable machine learning models are trained for automated data analysis and to speed up data comprehension. The establishment of materials libraries of multicomponent systems correlated with their properties (as in the present work), together with machine learning-based data analysis and theoretical approaches are opening pathways toward virtual development of novel materials for both functional and structural applications

Elucidation of the Transport Properties of Calcium‐Doped High Entropy Rare Earth Aluminates for Solid Oxide Fuel Cell Applications

Solid oxide fuel cells (SOFCs) are paving the way to clean energy conversion,relying on efficient oxygen-ion conductors with high ionic conductivitycoupled with a negligible electronic contribution. Doped rare earth aluminatesare promising candidates for SOFC electrolytes due to their high ionicconductivity. However, they often suffer from p-type electronic conductivity atoperating temperatures above 500°C under oxidizing conditions caused bythe incorporation of oxygen into the lattice. High entropy materials are a newclass of materials conceptualized to be stable at higher temperatures due totheir high configurational entropy. Introducing this concept to rare earthaluminates can be a promising approach to stabilize the lattice by shifting thestoichiometric point of the oxides to higher oxygen activities, and thereby,reducing the p-type electronic conductivity in the relevant oxygen partialpressure range. In this study, the high entropy oxide (Gd,La,Nd,Pr,Sm)AlO3issynthesized and doped with Ca. The Ca-doped (Gd,La,Nd,Pr,Sm)AlO3compounds exhibit a higher ionic conductivity than most of thecorresponding Ca-doped rare earth aluminates accompanied by a reduction ofthe p-type electronic conductivity contribution typically observed underoxidizing conditions. In light of these findings, this study introduces highentropy aluminates as a promising candidate for SOFC electrolytes

High Entropy Approach to Engineer Strongly Correlated Functionalities in Manganites

Technologically relevant strongly correlated phenomena such as colossal magnetoresistance (CMR) and metal-insulator transitions (MIT) exhibited by perovskite manganites are driven and enhanced by the coexistence of multiple competing magneto-electronic phases. Such magneto-electronic inhomogeneity is governed by the intrinsic lattice-charge-spin-orbital correlations, which, in turn, are conventionally tailored in manganites via chemical substitution, charge doping, or strain engineering. Alternately, the recently discovered high entropy oxides (HEOs), owing to the presence of multiple-principal cations on a given sub-lattice, exhibit indications of an inherent magneto-electronic phase separation encapsulated in a single crystallographic phase. Here, the high entropy (HE) concept is combined with standard property control by hole doping in a series of single-phase orthorhombic HE-manganites (HE-Mn), (Gd$_{0.25}$La$_{0.25}$Nd$_{0.25}$Sm$_{0.25}$)$_{1-x}$Sr$_x$MnO$_3$ (x = 0–0.5). High-resolution transmission microscopy reveals hitherto-unknown lattice imperfections in HEOs: twins, stacking faults, and missing planes. Magnetometry and electrical measurements infer three distinct ground states—insulating antiferromagnetic, unpercolated metallic ferromagnetic, and long-range metallic ferromagnetic—coexisting or/and competing as a result of hole doping and multi-cation complexity. Consequently, CMR ≈1550% stemming from an MIT is observed in polycrystalline pellets, matching the best-known values for bulk conventional manganites. Hence, this initial case study highlights the potential for a synergetic development of strongly correlated oxides offered by the high entropy design approach

Plasmodium falciparum Choline Kinase Inhibition Leads to a Major Decrease in Phosphatidylethanolamine Causing Parasite Death

This work was supported by Agencia Aragonesa para la Investigación y Desarrollo (ARAID), Ministerio de Economía y Competitividad (CTQ2013-44367-C2-2-P to R.H.-G.) and Diputación General de Aragón (DGA; B89 to R.H.-G.) and the EU Seventh Framework Programme (2007–2013) under BioStruct-X (grant agreement 283570 and BIOSTRUCTX 5186, to R.H.-G.). T.K.S. was supported by the Wellcome Trust grant 093228 and European Community’s Seventh Framework Programme under grant agreement No. 602773 (Project KINDRED).Malaria is a life-threatening disease caused by different species of the protozoan parasite Plasmodium, with P. falciparum being the deadliest. Increasing parasitic resistance to existing antimalarials makes the necessity of novel avenues to treat this disease an urgent priority. The enzymes responsible for the synthesis of phosphatidylcholine and phosphatidylethanolamine are attractive drug targets to treat malaria as their selective inhibition leads to an arrest of the parasite’s growth and cures malaria in a mouse model. We present here a detailed study that reveals a mode of action for two P. falciparum choline kinase inhibitors both in vitro and in vivo. The compounds present distinct binding modes to the choline/ethanolamine-binding site of P. falciparum choline kinase, reflecting different types of inhibition. Strikingly, these compounds primarily inhibit the ethanolamine kinase activity of the P. falciparum choline kinase, leading to a severe decrease in the phosphatidylethanolamine levels within P. falciparum, which explains the resulting growth phenotype and the parasites death. These studies provide an understanding of the mode of action, and act as a springboard for continued antimalarial development efforts selectively targeting P. falciparum choline kinase.Publisher PDFPeer reviewe