Study of V2CTx-MXene Based Immunosensor for Sensitive Label-Free Impedimetric Detection of SARS-CoV-2 Spike Protein.

Rapid and reliable immunosensing is undoubtedly one of the priorities in the efficient management and combat against a pandemic, as society has experienced with the SARS-CoV-2 outbreak; simple and cost-effective sensing strategies are at the forefront of these efforts. In this regard, 2D-layered MXenes hold great potential for electrochemical biosensing due to their attractive physicochemical properties. Herein, we present a V2CTx MXene-based sensing layer as an integral part of a label-free immunosensor for sensitive and selective detection of the SARS-CoV-2 spike protein. The sensor was fabricated on a supporting screen-printed carbon electrode using Nafion as an immobilizing agent for MXene and glutaraldehyde, the latter enabling effective binding of protein A for further site-oriented immobilization of anti-SARS-CoV-2 antibodies. A thorough structural analysis of the sensor architecture was carried out, and several key parameters affecting the fabrication and analytical performance of the immunosensor were investigated and optimized. The immunosensor showed excellent electroanalytical performance in combination with an impedimetric approach and exhibited a low detection limit of only 45 fM SARS-CoV-2 spike protein. Its practical applicability was successfully demonstrated by measuring the spike protein in a spiked artificial nasopharyngeal fluid sample.

Reaction Mechanism and Performance of Innovative 2D Germanane-Silicane Alloys: SixGe1- xH Electrodes in Lithium-Ion Batteries.

The adjustable structures and remarkable physicochemical properties of 2D monoelemental materials, such as silicene and germanene, have attracted significant attention in recent years. They can be transformed into silicane (SiH) and germanane (GeH) through covalent functionalization via hydrogen atom termination. However, synthesizing these materials with a scalable and low-cost fabrication process to achieve high-quality 2D SiH and GeH poses challenges. Herein, groundbreaking 2D SiH and GeH materials with varying compositions, specifically Si0.25Ge0.75H, Si0.50Ge0.50H, and Si0.75Ge0.25H, are prepared through a simple and efficient chemical exfoliation of their Zintl phases. These 2D materials offer significant advantages, including their large surface area, high mechanical flexibility, rapid electron mobility, and defect-rich loose-layered structures. Among these compositions, the Si0.50Ge0.50H electrode demonstrates the highest discharge capacity, reaching up to 1059 mAh g-1 after 60 cycles at a current density of 75 mA g-1. A comprehensive ex-situ electrochemical analysis is conducted to investigate the reaction mechanisms of lithiation/delithiation in Si0.50Ge0.50H. Subsequently, an initial assessment of the c-Li15(SixGe1- x)4 phase after lithiation and the a-Si0.50Ge0.50 phase after delithiation is presented. Hence, this study contributes crucial insights into the (de)lithiation reaction mechanisms within germanane-silicane alloys. Such understanding is pivotal for mastering promising materials that amalgamate the finest properties of silicon and germanium.

Tuning Germanane Band Gaps via Cyanoethyl Functionalization for Cutting-Edge Photoactive Cathodes: Photoenhanced Hybrid Zinc-Ion Capacitor Evaluation.

Energy harvesting and storing by dual-functional photoenhanced (photo-E) energy storage devices are being developed to battle the current energy hassles. In this research work, our investigations on the photoinduced efficiency of germanane (Ge-H) and its functionalized analogue cyanoethyl (Ge-C2-CN) are assessed as photocathodes in photo-E hybrid zinc-ion capacitors (ZICs). The evaluated self-powered photodetector devices made by these germanene-based samples revealed effective performances in photogenerated electrons and holes. The photo-E ZICs findings provided a photoinduced capacitance enhancement of ∼52% (for Ge-H) and ∼26% (for Ge-C2-CN) at a scan rate of 10 mV s-1 under 100 mW cm-2 illumination with 435 nm wavelength. Further characterizations demonstrated that the photo-E ZIC with Ge-C2-CN supply higher specific capacitance (∼6000 mF g-1), energy density (∼550 mWh kg-1), and power density (∼31,000 mW kg-1), compared to the Ge-H. In addition, capacitance retention of photo-E ZIC with Ge-C2-CN is ∼91% after 3000 cycles which is almost 6% greater than Ge-H. Interestingly, the photocharging voltage response in photo-E ZIC made by Ge-C2-CN is 1000 mV, while the photocharging voltage response with Ge-H is approximately 970 mV. The observed performances in Ge-H-based photoactive cathodes highlight the pivotal role of such two-dimensional materials to be applied as single architecture in new unconventional energy storage systems. They are particularly noteworthy when compared to the other advanced photo-E supercapacitors and could even be enhanced greatly with other suitable inorganic and organic functional precursors.

Psychological well-being as a motive for and result of post-bariatric body contouring procedures.

Objective: This study investigates whether psychological well-being in post-bariatric patients seeking body contouring procedures differs from those who do not seek body contouring procedures, those who have already undergone body contouring procedures, and those who are unsure about body contouring procedures. Methods: An anonymous, nonrandomized, cross-sectional survey study was designed. Psychological well-being of four groups of post-bariatric-patients (undergone body contouring procedures, seeking body contouring procedures, not seeking body contouring procedures, unsure about body contouring procedures) were compared. Results: A total of 345 patients were included in this study. No significant difference between patients seeking body contouring procedures and those not seeking body contouring procedures was found with regard to depressive symptoms, self-esteem, and body image. Patients who had already undergone body contouring procedures scored lower on depressive symptoms (p = 0.035) and reported feeling more attractive (p < 0.001) and less insecure (p = 0.030) than patients who had not yet undergone body contouring procedures but sought it. Satisfaction with the result of the body contouring procedures was associated with lower depression levels (p < 0.001), higher self-esteem (p < 0.001) and a more positive body-image (p < 0.001). Conclusions: Depressive symptoms or low self-esteem are not motivational factors for post-bariatric patients to seek body contouring procedures. Body contouring procedures are associated with improvement in psychological well-being in post-bariatric patients. Patients' satisfaction with the result of the body contouring procedures is significantly associated with positive psychological well-being.

In Situ Vanadium-Deficient Engineering of V2 C MXene: A Pathway to Enhanced Zinc-Ion Batteries.

This research examines vanadium-deficient V2 C MXene, a two-dimensional (2D) vanadium carbide with exceptional electrochemical properties for rechargeable zinc-ion batteries. Through a meticulous etching process, a V-deficient, porous architecture with an expansive surface area is achieved, fostering three-dimensional (3D) diffusion channels and boosting zinc ion storage. Analytical techniques like scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller, and X-ray diffraction confirm the formation of V2 C MXene and its defective porous structure. X-ray photoelectron spectroscopy further verifies its transformation from the MAX phase to MXene, noting an increase in V3+ and V4+ states with etching. Cyclic voltammetry reveals superior de-zincation kinetics, evidenced by consistent V3+ /V4+ oxidation peaks at varied scanning rates. Overall, this V-deficient MXene outperforms raw MXenes in capacity and rate, although its capacity diminishes over extended cycling due to structural flaws. Theoretical analyses suggest conductivity rises with vacancies, enhancing 3D ionic diffusion as vacancy size grows. This work sheds light on enhancing V-based MXene structures for optimized zinc-ion storage.

Bilateral deep brain stimulation of the subthalamic nucleus: Targeting differences between the first and second side / Estimulación cerebral profunda bilateral del núcleo subtalámico: diferencias de posicionamiento entre el primer y el segundo lado

Introduction and objectives Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a recognized treatment for drug-refractory Parkinson's disease (PD). However, the therapeutic success depends on the accuracy of targeting. This study aimed to evaluate potential accuracy differences in the placement of the first and second electrodes implanted, by comparing chosen electrode trajectories, STN activity detected during microelectrode recording (MER), and the mismatch between the initially planned and final electrode positions on each side. Materials and methods In this retrospective cohort study, we analyzed data from 30 patients who underwent one-stage bilateral DBS. For most patients, three arrays of microelectrodes were used to determine the physiological location of the STN. Final target location depended also on the results of intraoperative stimulation. The choice of central versus non-central channels was compared. The Euclidean vector deviation was calculated using the initially planned coordinates and the final position of the tip of the electrode according to a CT scan taken at least a month after the surgery. Results The central channel was chosen in 70% of cases on the first side and 40% of cases on the second side. The mean length of high-quality STN activity recorded in the central channel was longer on the first side than the second (3.07±1.85mm vs. 2.75±1.94mm), while in the anterior channel there were better MER recordings on the second side (1.59±2.07mm on the first side vs. 2.78±2.14mm on the second). Regarding the mismatch between planned versus final electrode position, electrodes on the first side were placed on average 0.178±0.917mm lateral, 0.126±1.10mm posterior and 1.48±1.64mm inferior to the planned target (AU)

Introducción y objetivos La estimulación cerebral profunda (ECP) del núcleo subtalámico (NST) es reconocida como un tratamiento para la enfermedad de Parkinson (EP) refractaria al tratamiento farmacológico. Sin embargo, el éxito de esta intervención depende de la precisión de la colocación de los electrodos. Este estudio tuvo como objetivo evaluar las posibles diferencias de precisión entre la colocación del primer y segundo electrodo, comparando las trayectorias elegidas para cada lado, la actividad del NST detectada durante el microrregistro (MER) y la discrepancia entre las posiciones inicialmente planeadas y las finales. Materiales y métodos En este estudio retrospectivo analizamos datos de 30 pacientes sometidos a ECP bilateral. En la mayoría de los casos se usaron tres conjuntos de microelectrodos para determinar la ubicación fisiológica del NST. El posicionamiento final del electrodo estuvo asimismo condicionado por los resultados de la estimulación intraoperatoria. Se comparó la elección de canales centrales vs. no centrales. El vector euclidiano del desvío se calculó a partir de las coordenadas planeadas inicialmente y la posición final de la punta del electrodo, según una tomografía computarizada realizada al menos un mes después de la cirugía. Resultados La trayectoria central se eligió en 70% de los casos en el primer lado y en el 40% de los casos en el segundo lado. La duración media de la actividad de alta calidad del NST registrada en el canal central fue mayor en el primer lado que en el segundo (3,07±1,85mm vs. 2,75±1,94mm), mientras que en el canal anterior hubo mejores registros de MER en el segundo lado (1,59±2,07mm en el primer lado vs. 2,78±2,14mm en el segundo) (AU)

Study of Chitosan-Stabilized Ti3C2Tx MXene for Ultrasensitive and Interference-Free Detection of Gaseous H2O2.

The development of sensitive, selective, and reliable gaseous hydrogen peroxide (H2O2) sensors operating at room temperature still represents a remaining challenge. In this work, we have investigated and combined the advantageous properties of a two-dimensional Ti3C2Tx MXene material that exhibits a large specific surface area and high surface activity, with favorable conducting and stabilizing properties of chitosan. The MXene-chitosan membrane was deposited on the ferrocyanide-modified screen-printed working carbon electrode, followed by applying poly(acrylic acid) as an electrolyte and accumulation medium for gaseous H2O2. The sensor showed highly sensitive and selective electroanalytical performance for detecting trace concentrations of gaseous H2O2 with a very low detection limit of 4 µg m-3 (4 ppbv), linear response in the studied concentration range of 0.5-30.0 mg m-3, and good reproducibility with an RSD of 1.3%. The applicability of the sensor was demonstrated by point-of-interest detection of gaseous H2O2 during the real hair bleaching process with a 9 and 12% H2O2 solution.

Structure Design and Processing Strategies of MXene-Based Materials for Electromagnetic Interference Shielding.

The development of new materials for electromagnetic interference (EMI) shielding is an important area of research, as it allows for the creation of more effective and high-efficient shielding solutions. In this sense, MXenes, a class of 2D transition metal carbides and nitrides have exhibited promising performances as EMI shielding materials. Electric conductivity, low density, and flexibility are some of the properties given by MXene materials, which make them very attractive in the field. Different processing techniques have been employed to produce MXene-based materials with EMI shielding properties. This review summarizes processes and the role of key parameters like the content of fillers and thickness in the desired EMI shielding performance. It also discusses the determination of power coefficients in defining the EMI shielding mechanism and the concept of green shielding materials, as well as their influence on the real application of a produced material. The review concludes with a summary of current challenges and prospects in the production of MXene materials as EMI shields.

The Influence of Obesity on Melanoma and Sentinel Lymph Node Diagnosis: A Retrospective Monocentric Study in 1001 Patients.

(1) Background: While obesity is a known independent risk factor in the development of melanoma, there is no consensus on its influence on melanoma prognosis. (2) Methods: In a monocentric retrospective study, data was collected from patients who underwent sentinel lymph node (SLN) biopsy for stage IB-IIC melanoma between 2013 and 2018. Patients were divided into groups according to their body mass index (BMI). The association between BMI and melanoma features, as well as the risk factors for metastases in SLN were examined. (3) Results: Of the 1001 patients, 336 had normal weight (BMI < 25), 402 were overweight (BMI >= 25 and <30), 173 obese (BMI >= 30 and <35) and 90 extremely obese (BMI >= 35). Overweightness and obesity were associated with higher tumor thicknesses at time of diagnosis. Ulceration was not influenced by the patient's weight. Metastases in sentinel lymph node was almost twice more likely in extremely obese patients than in normal weight patients. Independent risk factors for metastases in SLN in our study were tumor thickness, ulceration, and BMI > 35. (4) Conclusions: This is the first study to show higher metastases rates in high-BMI patients with melanoma, raising important questions regarding the screening and treatment of this specific patient population.

Psychoeducational Intervention for Reducing Heart Failure Patients' Rehospitalizations and Promoting Their Quality of Life and Posttraumatic Growth at the 1-Year Follow-Up: A Randomized Clinical Trial.

OBJECTIVE: This study's aim was to verify whether a psychoeducational intervention, with a brief expressive posttraumatic growth (PTG) component, could reduce heart failure (HF) patients' hospital readmissions and promote their quality of life (QoL) and PTG. METHODS: It adopted a parallel randomized clinical trial design, and its participants comprised HF patients from a hospital in Southern Brazil. All the participants completed the World Health Organization Quality of Life Assessment and Posttraumatic Growth Inventory questionnaires at the pre (T1: baseline) and post (T2) assessments of the intervention. Although patients in the control group (CG) underwent only regular outpatient consultations, those in the intervention group (IG) supplemented their regular consultations, with two additional individual visits to promote health and psychological education. At the 1-year follow-up, hospital readmissions were assessed. RESULTS: Of the 142 patients recruited at baseline (72 and 70 in the CG and IG, respectively), as 19 dropped out at follow-up, only 123 (63 and 60 in the CG and IG, respectively) were reassessed after approximately 378 days. They included 65% men aged 64 (11) years, 58% had low incomes, and 67% had less than high school education. The IG participants' risk of readmission got reduced by 52% ( p = .023), and they also showed significant improvements in their total QoL and positive psychological growth at the 6-month follow-up assessment. CONCLUSIONS: The two-session psychoeducational intervention proved to be protective for Southern Brazilian HF patients in the IG, as it effectively reduced their hospital readmission rates by half compared with the CG, as well as improved their QoL and promoted their positive psychological growth. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04870918 .

Bilateral deep brain stimulation of the subthalamic nucleus: Targeting differences between the first and second side.

INTRODUCTION AND OBJECTIVES: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a recognized treatment for drug-refractory Parkinson's disease (PD). However, the therapeutic success depends on the accuracy of targeting. This study aimed to evaluate potential accuracy differences in the placement of the first and second electrodes implanted, by comparing chosen electrode trajectories, STN activity detected during microelectrode recording (MER), and the mismatch between the initially planned and final electrode positions on each side. MATERIALS AND METHODS: In this retrospective cohort study, we analyzed data from 30 patients who underwent one-stage bilateral DBS. For most patients, three arrays of microelectrodes were used to determine the physiological location of the STN. Final target location depended also on the results of intraoperative stimulation. The choice of central versus non-central channels was compared. The Euclidean vector deviation was calculated using the initially planned coordinates and the final position of the tip of the electrode according to a CT scan taken at least a month after the surgery. RESULTS: The central channel was chosen in 70% of cases on the first side and 40% of cases on the second side. The mean length of high-quality STN activity recorded in the central channel was longer on the first side than the second (3.07±1.85mm vs. 2.75±1.94mm), while in the anterior channel there were better MER recordings on the second side (1.59±2.07mm on the first side vs. 2.78±2.14mm on the second). Regarding the mismatch between planned versus final electrode position, electrodes on the first side were placed on average 0.178±0.917mm lateral, 0.126±1.10mm posterior and 1.48±1.64mm inferior to the planned target, while the electrodes placed on the second side were 0.251±1.08mm medial, 0.355±1.29mm anterior and 2.26±1.47mm inferior to the planned target. CONCLUSION: There was a tendency for the anterior trajectory to be chosen more frequently than the central on the second side. There was also a statistically significant deviation of the second electrodes in the anterior and inferior directions, when compared to the electrodes on the first side, suggesting that another cause other than brain shift may be responsible. We should therefore factor this during planning for the second implanted side. It might be useful to plan the second side more anteriorly, possibly reducing the number of MER trajectories tested and the duration of surgery.

MORBIDITY AND SURVIVAL AFTER PERIOPERATIVE CHEMOTHERAPY IN GASTRIC CANCER: A STUDY USING THE BECKER'S CLASSIFICATION AND REGRESSION.

BACKGROUND: Gastric cancer is an aggressive neoplasm with a poor prognosis. The multimodal approach with perioperative chemotherapy is currently the recommended treatment for patients with locally advanced gastric cancer. This treatment induces a histopathological response expressed either through the degree of regression of the primary tumor or of the lymph nodes or through yTNM staging. Despite its advantages, there are still doubts regarding the effects of chemotherapy on postoperative morbidity and mortality. AIMS: This study aims to evaluate the impact of perioperative chemotherapy and its effect on anatomopathological results and postoperative morbidity and on patient survival. METHODS: This is an observational retrospective study on 134 patients with advanced gastric cancer who underwent perioperative chemotherapy and curative radical surgery. The degree of histological regression of the primary tumor was evaluated according to Becker's criteria; the proportion of regressed lymph nodes was determined, and postoperative complications were evaluated according to the Clavien-Dindo classification. Survival times were compared between the groups using Kaplan-Meier curves and the Mantel-Cox log-rank test. RESULTS: In all, 22.3% of the patients were classified as good responders and 75.9% as poor responders. This variable was not correlated with operative morbidity (p=1.68); 64.2% of patients had invaded lymph nodes and 46.3% had regressed lymph nodes; and 49.4% had no lymphatic invasion and 61.9% had no signs of venous invasion. Postoperative complications occurred in 30.6% of the patients. The group of good responders had an average survival of 56.0 months and the group of poor responders had 34.0 months (p=0.17). CONCLUSION: Perioperative chemotherapy induces regression in both the primary tumor and lymph nodes. The results of the operative morbidity were similar to those described in the literature. However, although the group of good responders showed better survival, this value was not significant. Therefore, further studies are needed to evaluate the importance of the degree of lymph node regression and its impact on the survival of these patients.

2D Layered Bimetallic Phosphorous Trisulfides MI MIII P2 S6 (MI = Cu, Ag; MIII = Sc, V, Cr, In) for Electrochemical Energy Conversion.

Considerable improvements in the electrocatalytic activity of 2D metal phosphorous trichalcogenides (M2 P2 X6 ) have been achieved for water electrolysis, mostly with MII 2 [P2 X6 ]4- as catalysts for hydrogen evolution reaction (HER). Herein, MI MIII P2 S6 (MI  = Cu, Ag; MIII  = Sc, V, Cr, In) are synthesized and tested for the first time as electrocatalysts in alkaline media, towards oxygen reduction reaction (ORR) and HER. AgScP2 S6 follows a 4 e- pathway for the ORR at 0.74 V versus reversible hydrogen electrode; CuScP2 S6 is active for HER, exhibiting an overpotential of 407 mV and a Tafel slope of 90 mV dec-1 . Density functional theory models reveal that bulk AgScP2 S6 and CuScP2 S6 are both semiconductors with computed bandgaps of 2.42 and 2.23 eV, respectively and overall similar electronic properties. Besides composition, the largest difference in both materials is in their molecular structure, as Ag atoms sit at the midpoint of each layer alongside Sc atoms, while Cu atoms are raised to a similar height to S atoms, in the external segment of the 2D layers. This structural difference probably plays a fundamental role in the different catalytic performances of these materials. These findings show that MI (Cu, Ag) together with Sc(MIII ) leads to promising achievements in MI MIII P2 S6 materials as electrocatalysts.

Arthroscopic Treatment of Freiberg Disease - Case Report.

Freiberg disease is a rare condition whose diagnosis requires a high clinical suspicion. Avascular necrosis of the metatarsal head progresses with articular collapse, leading to forefoot pain and limitation of the daily activities. Several surgical techniques have been described to address the disease, and since it is usually diagnosed in later-stages, most of them include joint-destructive procedures. The use of arthroscopy on the small joint of the foot has arisen in the last few years, but its application in Freiberg disease is still scant. Joint-preserving procedures have been advocated for cases of early-stage disease, aiming to relieve symptoms while preventing the progression of the disease. In the present report, we describe a successful treatment of a 12-year-old patient with early-stage Freiberg disease using core decompression and bone marrow graft through a minimally-invasive approach assisted by arthroscopy.

Arthroscopic Treatment of Freiberg Disease - Case Report / Tratamento artroscópico da doença de Freiberg - Relato de caso

Abstract Freiberg disease is a rare condition whose diagnosis requires a high clinical suspicion. Avascular necrosis of the metatarsal head progresses with articular collapse, leading to forefoot pain and limitation of the daily activities. Several surgical techniques have been described to address the disease, and since it is usually diagnosed in later-stages, most of them include joint-destructive procedures. The use of arthroscopy on the small joint of the foot has arisen in the last few years, but its application in Freiberg disease is still scant. Joint-preserving procedures have been advocated for cases of early-stage disease, aiming to relieve symptoms while preventing the progression of the disease. In the present report, we describe a successful treatment of a 12-year-old patient with early-stage Freiberg disease using core decompression and bone marrow graft through a minimally-invasive approach assisted by arthroscopy.

Resumo A doença de Freiberg é rara, e seu diagnóstico requer alto grau de suspeita clínica. A necrose avascular da cabeça do metatarso progride com colapso articular, e causa dor no antepé e limitação da atividade. Há diversas técnicas cirúrgicas para o tratamento da doença; como o diagnóstico geralmente é feito em estágios posteriores, a maioria dessas técnicas inclui procedimentos de destruição articular. A artroscopia tem sido utilizada nas pequenas articulações do pé nos últimos anos, mas sua aplicação na doença de Freiberg ainda é escassa. Procedimentos de preservação articular têm sido preconizados na doença em estágio inicial, com o objetivo de aliviar os sintomas e impedir a progressão. Neste relato, descrevemos o tratamento bem-sucedido de uma paciente de 12 anos de idade com doença de Freiberg em estágio inicial por meio de descompressão central e enxerto de medula óssea, por meio de abordagem minimamente invasiva assistida por artroscopia.

Searching for an Endoscopic All-Inside Classic Broström-Gould Technique.

Ankle sprains represent one of the most common injuries sustained by professional and recreational athletes. For those who develop chronic instability requiring surgery, the Broström-Gould procedure has been advocated as the gold standard treatment. Many arthroscopic techniques have been developed in the attempt to replicate this procedure. However, since both calcaneofibular ligament and inferior extensor retinaculum are extra-capsular structures, some of these techniques include a stand-alone repair of the anterior talofibular ligament, while others add a mini-open or a percutaneous modification to perform the Gould augmentation. In our technique, lateral ankle endoscopy provides a clear view and access to these structures, allowing for an all-inside Broström-Gould using three portals. The procedure is safe and reproducible, resulting in a repair that mostly resembles the classical open technique.

Synthesis of Magnesium Phosphorous Trichalcogenides and Applications in Photoelectrochemical Water Splitting.

Promising applications of metal phosphorous trichalcogenides (M2 P2 X6 or MPX3 ) have been predicted in optoelectronics, photoelectrocatalysis, and water-splitting reactions, mainly due to its wide bandgap. Transition metals are widely used in the synthesis of MPX3 , however, divalent cations of alkaline earth metals can also be constituents in MPX3 2D layered structures. Herein, MgPX3 (X = S, Se) are synthesized and their photoelectrochemical (PEC) activity is tested in the hydrogen evolution and oxygen evolution reaction (OER) regions under a wide range of wavelengths. MgPSe3 photoelectrode shows the best PEC performance with a response of 1.6 ± 0.1 mA cm-2 under 420 nm. In the light-assisted OER, a 200 mV improvement is obtained in the overpotential at 10 mA cm-2 for MgPSe3 . The better performance of MgPSe3 is consistent with its lower optical bandgap (Eg  = 3.15 eV), as a result of the variation of electronegativity between selenide and sulfide.

Are the neglected tropical diseases under control in the tri-border region between Brazil, Argentina, and Paraguay?

INTRODUCTION: Implementation of prevention and control measures for communicable diseases in border regions can be challenging and lead to inefficient attempts to control them. We describe evidences on the strengths, weaknesses, opportunities and challenges regarding implementation of health interventions for control, prevention and treatment of selected neglected tropical diseases (NTD), a group of transmissible diseases typically prevalent in tropical countries and vulnerable populations, in the tri-border between Brazil, Argentina, and Paraguay. METHODOLOGY: A systematic literature review of observational and experimental studies was conducted, using PubMed and Bireme databases. Eligibility criteria were location (tri-border area) and subject (health interventions). RESULTS: Of a total of 595 references identified, 34 studies were included (18 pertaining to leishmaniasis, 11 to dengue, 2 to leprosy, 2 to soil-transmitted helminthiases and 1 to Chagas' disease), with an inclusion rate of 6.4%. The main strengths were the similarity of health interventions between countries and easiness of mobility and communication flows. The main weaknesses were access to rural areas and discrepancies in the number of studies between countries. As for opportunities, we identified increased tourism, economic development and recent increasing research in this field. The main challenges were the absence of studies regarding other prevalent NTD in the region and movement of goods, animals and people across borders. CONCLUSIONS: Although epidemiological studies are still needed to better understand and assess the prevalence of NTD in the area, mainly in Paraguay, these findings can inform decision-makers and health managers to plan a common strategy to address NTD.

InSe:Ge-doped InSe van der Waals heterostructure to enhance photogenerated carrier separation for self-powered photoelectrochemical-type photodetectors.

Two-dimensional (2D) van der Waals (vdW) materials with tunable heterostructures and superior optoelectronic properties have opened a new platform for various applications, e.g., field-effect transistors, ultrasensitive photodetectors and photocatalysts. In this work, an InSe/InSe(Ge) (germanium doped InSe) vdW heterostructure is designed to improve the photoresponse performance of sole InSe in a photoelectrochemical (PEC)-type photodetector. Photoelectrochemical measurements demonstrated that this heterostructure has excellent photoresponse characteristics, including a photocurrent density of 9.8 µA cm-2, a photo-responsivity of 64 µA W-1, and a response time/recovery time of 0.128 s/0.1 s. Moreover, the measurements also revealed the self-powering capability and long-term cycling stability of this heterostructure. The electronic properties of the prepared pure and Ge-doped single crystals unveiled a negative and temperature-independent thermoelectric power and temperature-activated resistivity. The negative character of dominating charge carriers was confirmed by Hall measurements, which corroborated by electrical resistivity revealed a carrier concentration below ∼1015 cm-3 and an electron mobility of ∼500 cm2 V-1 s-1 in Ge-doped crystals. Additionally, the Mott-Schottky model explored the mechanism of charge transfer and enhanced PEC performance. Band bending at the InSe/InSe(Ge)-electrolyte interface benefits the separation and transformation of photogenerated carriers from the heterostructure to electrolyte due to the tunable energy band alignment. These results indicate that the InSe/InSe(Ge) vdW heterostructure is promising for PEC-type photodetectors, which provide a novel way to utilize 2D vdW heterostructures in optoelectronics.