Blade-Coating of High Crystallinity Cesium-Formamidinium Perovskite Formulations.

Up-scalable coating processes need to be developed to manufacture efficient and stable perovskite-based solar modules. In this work, we combine two Lewis base additives (N,N'-dimethylpropyleneurea and thiourea) to fabricate high-quality Cs0.15FA0.85PbI3 perovskite films by blade-coating on large areas. Selected-area electron diffraction patterns reveal a minimization of stacking faults in the α-FAPbI3 phase for this specific cesium-formamidinium composition in both spin-coated and blade-coated perovskite films, demonstrating its scaling potential. The underlying mechanism of the crystallization process and the specific role of thiourea are characterized by Fourier transform infrared spectroscopy and in situ optical absorption, showing clear interaction between thiourea and perovskite precursors and halved film-formation activation energy (from 114 to 49 kJ/mol), which contribute to the obtained specific morphology with the formation of large domain sizes on a short time scale. The blade-coated perovskite solar cells demonstrate a maximum efficiency of approximately 16.9% on an aperture area of 1 cm2.

Alleviating nanostructural phase impurities enhances the optoelectronic properties, device performance and stability of cesium-formamidinium metal-halide perovskites.

The technique of alloying FA+ with Cs+ is often used to promote structural stabilization of the desirable α-FAPbI3 phase in halide perovskite devices. However, the precise mechanisms by which these alloying approaches improve the optoelectronic quality and enhance the stability have remained elusive. In this study, we advance that understanding by investigating the effect of cationic alloying in CsxFA1-xPbI3 perovskite thin-films and solar-cell devices. Selected-area electron diffraction patterns combined with microwave conductivity measurements reveal that fine Cs+ tuning (Cs0.15FA0.85PbI3) leads to a minimization of stacking faults and an increase in the photoconductivity of the perovskite films. Ultra-sensitive external quantum efficiency, kelvin-probe force microscopy and photoluminescence quantum yield measurements demonstrate similar Urbach energy values, comparable surface potential fluctuations and marginal impact on radiative emission yields, respectively, irrespective of Cs content. Despite this, these nanoscopic defects appear to have a detrimental impact on inter-grains'/domains' carrier transport, as evidenced by conductive-atomic force microscopy and corroborated by drastically reduced solar cell performance. Importantly, encapsulated Cs0.15FA0.85PbI3 devices show robust operational stability retaining 85% of the initial steady-state power conversion efficiency for 1400 hours under continuous 1 sun illumination at 35 °C, in open-circuit conditions. Our findings provide nuance to the famous defect tolerance of halide perovskites while providing solid evidence about the detrimental impact of these subtle structural imperfections on the long-term operational stability.

A Universal Perovskite/C60 Interface Modification via Atomic Layer Deposited Aluminum Oxide for Perovskite Solar Cells and Perovskite-Silicon Tandems.

The primary performance limitation in inverted perovskite-based solar cells is the interface between the fullerene-based electron transport layers and the perovskite. Atomic layer deposited thin aluminum oxide (AlOX) interlayers that reduce nonradiative recombination at the perovskite/C60 interface are developed, resulting in >60 millivolts improvement in open-circuit voltage and 1% absolute improvement in power conversion efficiency. Surface-sensitive characterizations indicate the presence of a thin, conformally deposited AlOx layer, functioning as a passivating contact. These interlayers work universally using different lead-halide-based absorbers with different compositions where the 1.55 electron volts bandgap single junction devices reach >23% power conversion efficiency. A reduction of metallic Pb0 is found and the compact layer prevents in- and egress of volatile species, synergistically improving the stability. AlOX-modified wide-bandgap perovskite absorbers as a top cell in a monolithic perovskite-silicon tandem enable a certified power conversion efficiency of 29.9% and open-circuit voltages above 1.92 volts for 1.17 square centimeters device area.

Medical Oxygen as a Life-Saving Medicine: A rapid review of the oxygen landscape and innovative efforts in the World Health Organization Eastern Mediterranean Region in Response to COVID-19 and Beyond.

Background: Medical oxygen is an essential treatment for life-threatening hypoxemic conditions and is commonly indicated for the clinical management of many leading causes of mortality. Many countries of the World Health Organization (WHO) Eastern Mediterranean Region (EMR) lacked robust medical oxygen systems prior to the COVID-19 (corona virus disease) pandemic and this situation was exacerbated by increased needs, particularly in remote and rural health facilities, resulting in many unfortunate deaths. The aim of this article is to describe the oxygen landscape in the region and the regional initiatives undertaken by countries and WHO. Methodology: We conducted a rapid review to synthesize the available literature on the needs and availability of oxygen and its related resources and the regional initiatives undertaken. We conducted search in PubMed, relevant WHO and World Bank websites, and in general using google to understand the health of conditions that could benefit from the availability of medical oxygen, oxygen related resources including health workforce available for support and usage of medical oxygen, and the initiatives by WHO, countries and partners to improve the situation. We used a snowballing technique and reviewed all available databases for reports, surveys, assessments, and studies related to medical oxygen, besides WHO internal records, assessments, and consultation reports. Results: The data on oxygen availability, supply demand gap, infrastructure facilities, and human resources were sparse. The regional initiatives have led to increase in resources, including human resources and oxygen production infrastructure. The Live Oxygen Platform (LOP), contributed to improved availability of quality data needed for supply demand assessments. Conclusion: A regional enterprise strategy to promote sustainable, decentralized, and contextualized production, supply, and monitoring of oxygen together with human resource support including training and placement by WHO, partners, and governments contributed to improved availability of oxygen in the region. Additionally, with the LOP, governments, WHO, and partners have access to better data availability for policy decision making and timely resource allocation.

Grading of Ultrasonography in Rheumatoid Arthritis of Wrist and Hand Joints.

RATIONALE AND OBJECTIVES: To evaluate the role of musculoskeletal ultrasound (MSUS) in the grading of rheumatoid arthritis (RA) wrist and hand joints and correlate it with clinical, laboratory, and radiological data. MATERIALS AND METHODS: A cross-sectional study recruited 50 patients in a tertiary care hospital. RA activity was assessed by DAS28. MSUS dorsal longitudinal scan was performed on the wrists, MCPs, and PIPS joints using high frequency (18 MHZ) linear transducer. 100 wrists in three different views, 500 MCPs, 500 PIPs were evaluated using the grayscale ultrasound and power Doppler ultrasound semiquantitative scale and scores ranging from 0-3. The results were correlated with clinical, laboratory and radiological data. All patients' wrist and hand joints X-rays were evaluated using the Larsen score. RESULTS: The mean age of the patients (49 females and one male) was 44.58 ± 10.07 years, and their mean disease duration was 16.26 ± 1.07 years. The mean DAS28 was 5.19 ± 0.95. 97.5% of joints had grade I Larsen score, 11.07% of the joints had erosions, 9.2% of the joints had effusions, 23.8% of the joints had synovial thickening, 11.9% of the joints showed PD signals and 3.5% of the joints were accompanied with tenosynovitis. Significant relations (p < 0.05) found among DAS28 and (PD signals, synovial thickening, tenosynovitis, effusion, and Larsen score). A nonsignificant relation (p > 0.05) among DAS28 and erosions detected by MSUS and X-ray. CONCLUSION: MSUS is powerful in the detection of early RA regarding synovitis, joint effusion, tenosynovitis, and bone erosions, which were correlated with clinical and laboratory parameters.

Circulating hematopoietic stem cells, endothelial progenitor cells and cancer stem cells in hepatocellular carcinoma patients: contribution to diagnosis and prognosis.

Background and aim: Circulating hematopoietic stem cells (HSCs), circulating endothelial progenitor cells (EPCs) and cancer stem cells (CSCs) contribute to tumor development and progression and can predict patient outcome. The aim of this study was to investigate the frequency of circulating HSCs, EPCs and CSCs in the peripheral blood of patients with hepatocellular carcinoma (HCC) and to explore their potential prognostic significance for HCC patients.Methods: The study included 30 HCC patients and 20 healthy controls. The HSCs and EPCs were enumerated with CD45, CD34, CD133, CD144 markers, while CSCs were enumerated with CD45, CD44, CD133 markers using flow cytometry.Results: The mean percentages of circulating HSCs were significantly lower in HCC patients than the controls (p = .001), whereas the mean percentages of EPCs within the HSCs subpopulation were significantly higher in the HCC patients than the controls (p = .002). The absolute count of CSCs within 100,000 peripheral blood mononuclear cells was 23.5 ± 3.4 in the HCC patients. Also, the mean percentages of circulating HSCs, EPCs and the number of CSCs were significantly increased in patients with multiple hepatic focal lesions than in patients with a single hepatic focal lesion. Both circulating HSCs and EPCs showed significant positive correlation with the level of AFP and with the numbers of CSCs. In the meantime, the numbers of CSCs revealed significant direct correlation with ALT, AST and AFP levels. The one-year overall survival (OS) of the patients was 77.5%. High levels of CSCs, HSCs and EPCs at diagnosis were all associated with worse outcome for the HCC patients.Conclusions: Significant changes in the levels of the circulating HSCs, EPCs and CSCs occur in HCC. These changes help the diagnosis and the prediction of HCC outcome, as higher levels of these cells are associated with worse OS.

Preoperative Grading of Glioma Using Dynamic Susceptibility Contrast MRI: Relative Cerebral Blood Volume Analysis of Intra-tumoural and Peri-tumoural Tissue.

OBJECTIVES: To assess the usefulness of intra-tumor and peri-tumoral relative cerebral blood volume (rCBV) in preoperative glioma grading. PATIENTS AND METHODS: 21 patients with histopathologically confirmed glioma were included. Imaging was achieved on a 1.5T MRI scanner. Dynamic susceptibility contrast (DSC) MRI was performed using T2* weighted gradient echo-planner imaging (EPI). Multiple regions of interest (ROIs) have been drawn in the hotspots regions, the highest ROI has been selected to represent the rCBV of each intra-tumoral and peri-tumoral regions. Based on histopathology, tumors were subdivided into low grade and high grade. Receiver operating characteristic analysis (ROC) of rCBV, of both intra-tumoral and peri-tumoral regions, was performed to find cut-off values between high and low-grade tumors. The resulting sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. RESULTS: Based on the histopathology, high-grade glioma (HGG) represented 76.2% whereas low-grade glioma (LGG) represented 23.8%. Both intra-tumoral and peri-tumoral rCBV of HGG were significantly higher than those of LGG. A cut-off value >2.9 for intra-tumoral rCBV provided sensitivity, specificity, and accuracy of 80%, 100%, and 85.7% respectively to differentiate between HGG and LGG. Additionally, the cut-off value >0.7 for peri-tumoral rCBV provided sensitivity, specificity, and accuracy of 100%, 66.6%, and 90.5% respectively to differentiate between HGG and LGG. CONCLUSION: rCBV of each of intra-tumoral and peri-tumoral rCBV are significantly reliable for the preoperative distinction between HGG and LGG. Combined intra-tumoral and peri-tumoral rCBV provides overall better diagnostic accuracy and helps to decrease the invasive intervention for non-surgical candidates.

Vitamin D status and viral response to therapy in hepatitis C infected children.

AIM: To study the frequency of vitamin D deficiency in patients with hepatitis C virus (HCV) infection and to evaluate the role of vitamin D supplementation in improving antiviral therapy. METHODS: Sixty-six children aged from 7-14 years (mean ± SD, 11.17±2.293) diagnosed with HCV infection were matched to 28 healthy controls. Serum levels of 25 (OH) D3, calcium, phosphorus, alkaline phosphatase and plasma level of parathormone were measured. Quantitative PCR for HCV was performed Bone density was determined by dual energy X-ray absorptiometry. All cases received conventional therapy, and only 33 patients received vitamin D supplementation. RESULTS: Children with HCV showed significantly increased levels of HCV RNA (P<0.001), parathormone (P<0.01) and decreased vitamin D levels (P<0.05) (33.3% deficient and 43.3% insufficient) compared with controls. Abnormal bone status (Z score -1.98±0.75) was found in ribs, L-spine, pelvis and total body. Cases treated with vitamin D showed significant higher early (P<0.04) and sustained (P<0.05) virological response. There was a high frequency of vitamin D deficiency among the Egyptian HCV children, with significant decrease in bone density. The vitamin D level should be assessed before the start of antiviral treatment with the correction of any detected deficiency. CONCLUSION: Adding vitamin D to conventional Peg/RBV therapy significantly improved the virological response and helped to prevent the risk of emerging bone fragility.