A Stable Integrated Photoelectrochemical Reactor for H₂ Production from Water Attains a Solar‐to‐Hydrogen Efficiency of 18 % at 15 Suns and 13 % at 207 Suns

The major challenge in solar water splitting to H_{2} and O_{2} is in making a stable and affordable system for large‐scale applications. We have designed, fabricated, and tested a photoelectrochemical reactor characterized as follows: 1) it comprises an integrated device to reduce the balance of the system cost, 2) it utilizes concentrated sunlight to reduce the photoabsorber cost, and 3) it employs and alkaline electrolyte to reduce catalyst cost and eliminate external thermal management needs. The system consists of an III‐V‐based photovoltaic cell integrated with Ni foil as an O_{2} evolution catalyst that also protects the cell from corrosion. At low light concentration, without the use of optical lenses, the solar‐to‐hydrogen (STH) efficiency was 18.3 %, while at high light concentration (up to 207 suns) with the use of optical lenses, the STH efficiency was 13 %. Catalytic tests conducted for over 100 hours at 100–200 suns showed no sign of degradation nor deviation from product stoichiometry (H_{2}/O_{2}=2). Further tests projected a system stability of years

Failure of woven fiber glass epoxy composite under charpy impact loading

Woven glass fiber reinforced epoxy composite at 55 vol% fiber content was fabricated using conventional hand lay-up method. The impact strength of the prepared samples were measured under Charpy impact test at +50oC and - 50oC temperature. The fractured surface of composite samples were investigated using scanning electron microscope. The impact energy for samples fractured at +50oC was at 380 KJm-2 whereas the low temperature of - 50oC showed impact energy of 178 KJm-2. The high plastic deformation from the sample tested at +50oC is the evidence from the high amount of absorbed energy compared to -50oC which revealed lower deformation. At this subzero temperature, the increased brittleness produced extensive matrix cracking and fiber splitting. However, scanning electron fractograph at +50oC showed mixed failure mode of large delaminations, fiber splitting and matrix cracking. The impact values of 380 KJm-2 and 178 KJm-2 tested at +50oC and -50oC respectively would suggest that this composite is suitable to replace steel for impact applications and is safe to be used at both high and low environmental temperatures

The effect of working distances on the formation of TiC composite surface hardening using TIG melting technique

Hardening surface layer with and without adding reinforcing material can be achieved by rapid solidification on the top substrate area via high energy input fusion. In this work, the TIG torch heat input at 1344 J/mm is fused at 0.5 mm and 1.5 mm of working distances to incorporate the preplaced TiC particulates on the surface of AISI 4340 low alloy steel. Results pertaining to the microstructural features, melt pool sizes, defects, topographies and microhardness were investigated using the optical microscope, scanning electron microscope and Vickers microhardness tester. The results showed that the heat loss through the arc column at 1.5 mm of working distance resulted small melt pool geometry and poor dissolution of TiC particulates. Narrowing this gap to 0.5 mm increases heating that made more precipitation of TiC whilst minimizing those the undissolved particulates. The surface engulfed with TiC of 0.5 mm near the arc source produced microhardness ranging from 800 HV to 1500 HV. The work suggested that heat fusion can be enhanced by marginal working distance whilst saving the energy to melt instead of increasing the used voltage, current, decreasing scanning speed or by preheating, post heating or adding fluxes shielding with special shielding gasses

Clinico-pathological features of erythema nodosum leprosum: A case-control study at ALERT hospital, Ethiopia.

BACKGROUND: Leprosy reactions are a significant cause of morbidity in leprosy population. Erythema nodosum leprosum (ENL) is an immunological complication affecting approximately 50% of patients with lepromatous leprosy (LL) and 10% of borderline lepromatous (BL) leprosy. ENL is associated with clinical features such as skin lesions, neuritis, arthritis, dactylitis, eye inflammation, osteitis, orchitis, lymphadenitis and nephritis. ENL is treated mainly with corticosteroids and corticosteroids are often required for extended periods of time which may lead to serious adverse effects. High mortality rate and increased morbidity associated with corticosteroid treatment of ENL has been reported. For improved and evidence-based treatment of ENL, documenting the systems affected by ENL is important. We report here the clinical features of ENL in a cohort of patients with acute ENL who were recruited for a clinico-pathological study before and after prednisolone treatment. MATERIALS AND METHODS: A case-control study was performed at ALERT hospital, Ethiopia. Forty-six LL patients with ENL and 31 non-reactional LL matched controls were enrolled to the study and followed for 28 weeks. Clinical features were systematically documented at three visits (before, during and after predinsolone treatment of ENL cases) using a specifically designed form. Skin biopsy samples were obtained from each patient before and after treatment and used for histopathological investigations to supplement the clinical data. RESULTS: Pain was the most common symptom reported (98%) by patients with ENL. Eighty percent of them had reported skin pain and more than 70% had nerve and joint pain at enrolment. About 40% of the patients developed chronic ENL. Most individuals 95.7% had nodular skin lesions. Over half of patients with ENL had old nerve function impairment (NFI) while 13% had new NFI at enrolment. Facial and limb oedema were present in 60% patients. Regarding pathological findings before treatment, dermal neutrophilic infiltration was noted in 58.8% of patients with ENL compared to 14.3% in LL controls. Only 14.7% patients with ENL had evidence of vasculitis at enrolment. CONCLUSION: In our study, painful nodular skin lesions were present in all ENL patients. Only 58% patients had dermal polymorphonuclear cell infiltration showing that not all clinically confirmed ENL cases have neutrophilic infiltration in lesions. Very few patients had histological evidence of vasculitis. Many patients developed chronic ENL and these patients require inpatient corticosteroid treatment for extended periods which challenges the health service facility in resource poor settings, as well as the patient's quality of life

Le mélanome primitif de la muqueuse génitale féminine: à propos de trois observations et revue de littérature

Le mélanome malin primitif de l'appareil génital féminin est une tumeur extrêmement rare. Il est fréquemment observé au niveau de la vulve mais il est rare au niveau du col utérin et du vagin. Il est le plus souvent   diagnostiqué à un stade tardif à l'occasion de métrorragies ou de massetumorale. Son histogénèse a été longtemps débattue. Le diagnostic est anatomo-pathologique avec recours nécessaire à l'étude   immunohistochimique. Sa prise en charge n'est pas codifiée avec plusieurs thérapeutiques proposées notamment dans le mélanome métastatique.Son pronostic est désastreux, associé à un taux élevé de récidives et à une courte survie. Les auteurs présentent trois observations, de  mélanomes primitifs vaginal, vulvaire et cervical, chez trois patientes âgées  respectivement de 70, 65 et 40 ans. Et à travers ces observations, ils mettent en relief les principaux aspects cliniques, histologiques, thérapeutiques de cette entité avec une revue de la littérature

Wear behaviour at 600°C of surface engineered low-alloy steel containing TiC particles

The work aimed to develop surfaces that could resist wear at high temperatures, thus achieving a prolonged component life. Surface modification of a low-alloy steel by incorporating TiC particles has been undertaken by melting the surface using a tungsten inert gas torch. The dry sliding wear behaviour at 600°C of the original and modified surfaces was compared. Microscopic examination of both surfaces showed glazed layers across the wear tracks, with differing amounts of oxide and homogeneity. Extensive wear occurred on the steel surface, which showed deformation of the wear scar tracks and a steadily increased friction coefficient. The TiC addition reduced the wear loss, coinciding with a glazed layer 33% thinner than that on the low-alloy steel sample

COVID‐19, nationalism, and the politics of crisis: A scholarly exchange

In this article, several scholars of nationalism discuss the potential for the COVID‐19 pandemic to impact the development of nationalism and world politics. To structure the discussion, the contributors respond to three questions: (1) how should we understand the relationship between nationalism and COVID‐19; (2) will COVID‐19 fuel ethnic and nationalist conflict; and (3) will COVID‐19 reinforce or erode the nation‐state in the long run? The contributors formulated their responses to these questions near to the outset of the pandemic, amid intense uncertainty. This made it acutely difficult, if not impossible, to make predictions. Nevertheless, it was felt that a historically and theoretically informed discussion would shed light on the types of political processes that could be triggered by the COVID‐19 pandemic. In doing so, the aim is to help orient researchers and policy‐makers as they grapple with what has rapidly become the most urgent issue of our times

PET/CT Imaging of Zr-89-N-sucDf-Pembrolizumab in Healthy Cynomolgus Monkeys

PURPOSE: Programmed cell death-1 receptor (PD-1) and its ligand (PD-L1) are the targets for immunotherapy in many cancer types. Although PD-1 blockade has therapeutic effects, the efficacy differs between patients. Factors contributing to this variability are PD-L1 expression levels and immune cells present in tumors. However, it is not well understood how PD-1 expression in the tumor microenvironment impacts immunotherapy response. Thus, imaging of PD-1-expressing immune cells is of interest. This study aims to evaluate the biodistribution of Zirconium-89 (89Zr)-labeled pembrolizumab, a humanized IgG4 kappa monoclonal antibody targeting PD-1, in healthy cynomolgus monkeys as a translational model of tracking PD-1-positive immune cells. PROCEDURES: Pembrolizumab was conjugated with the tetrafluorophenol-N-succinyl desferal-Fe(III) ester (TFP-N-sucDf) and subsequently radiolabeled with 89Zr. Four cynomolgus monkeys with no previous exposure to humanized monoclonal antibodies received tracer only or tracer co-injected with pembrolizumab intravenously over 5 min. Thereafter, a static whole-body positron emission tomography (PET) scan was acquired with 10 min per bed position on days 0, 2, 5, and 7. Image-derived standardized uptake values (SUVmean) were quantified by region of interest (ROI) analysis. RESULTS: 89Zr-N-sucDf-pembrolizumab was synthesized with high radiochemical purity (> 99 %) and acceptable molar activity (> 7 MBq/nmol). In animals dosed with tracer only, 89Zr-N-sucDf-pembrolizumab distribution in lymphoid tissues such as mesenteric lymph nodes, spleen, and tonsils increased over time. Except for the liver, low radiotracer distribution was observed in all non-lymphoid tissue including the lung, muscle, brain, heart, and kidney. When a large excess of pembrolizumab was co-administered with a radiotracer, accumulation in the lymph nodes, spleen, and tonsils was reduced, suggestive of target-mediated accumulation. CONCLUSIONS: 89Zr-N-sucDf-pembrolizumab shows preferential uptake in the lymphoid tissues including the lymph nodes, spleen, and tonsils. 89Zr-N-sucDf-pembrolizumab may be useful in tracking the distribution of a subset of immune cells in non-human primates and humans. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02760225

Rasch analysis of the Patient and Observer Scar Assessment Scale (POSAS) in burn scars

The Patient and Observer Scar Assessment Scale (POSAS) is a questionnaire that was developed to assess scar quality. It consists of two separate six-item scales (Observer Scale and Patient Scale), both of which are scored on a 10-point rating scale. After many years of experience with this scale in burn scar assessment, it is appropriate to examine its psychometric properties using Rasch analysis. Cross-sectional data collection from seven clinical trials resulted in a data set of 1,629 observer scores and 1,427 patient scores of burn scars. We examined the person-item map, item fit statistics, reliability, response category ordering, and dimensionality of the POSAS. The POSAS showed an adequate fit to the Rasch model, except for the item surface area. Person reliability of the Observer Scale and Patient Scale was 0.82 and 0.77, respectively. Dimensionality analysis revealed that the unexplained variance by the first contrast of both scales was 1.7 units. Spearman correlation between the Observer Scale Rasch measure and the overall opinion of the clinician was 0.75. The Rasch model demonstrated that the POSAS is a reliable and valid scale that measures the single-construct scar qualit

Comparison of Efficacy and Safety of Ciclosporin to Prednisolone in the Treatment of Erythema Nodosum Leprosum: Two Randomised, Double Blind, Controlled Pilot Studies in Ethiopia.

BACKGROUND: Erythema Nodosum Leprosum (ENL) is a serious complication of leprosy. It is normally treated with high dose steroids, but its recurrent nature leads to prolonged steroid usage and associated side effects. There is little evidence on the efficacy of alternative treatments for ENL, especially for patients who have become steroid resistant or have steroid side effects. These two pilot studies compare the efficacy and side effect profile of ciclosporin plus prednisolone against prednisolone alone in the treatment of patients with either new ENL or chronic and recurrent ENL. METHODS AND RESULTS: Thirteen patients with new ENL and twenty patients with chronic ENL were recruited into two double-blinded randomised controlled trials. Patients were randomised to receive ciclosporin and prednisolone or prednisolone treatment only. Patients with acute ENL had a delay of 16 weeks in the occurrence of ENL flare-up episode, with less severe flare-ups and decreased requirements for additional prednisolone. Patients with chronic ENL on ciclosporin had the first episode of ENL flare-up 4 weeks earlier than those on prednisolone, as well as more severe ENL flare-ups requiring 2.5 times more additional prednisolone. Adverse events attributable to prednisolone were more common that those attributable to ciclosporin. CONCLUSIONS: This is the first clinical trial on ENL management set in the African context, and also the first trial in leprosy to use patients' assessment of outcomes. Patients on ciclosporin showed promising results in the management of acute ENL in this small pilot study. But ciclosporin, did not appear to have a significant steroid-sparing effects in patients with chronic ENL, which may have been due to the prolonged use of steroids in these patients in combination with a too rapid decrease of steroids in patients given ciclosporin. Further research is needed to determine whether the promising results of ciclosporin in acute ENL can be reproduced on a larger scale