Motional Narrowing Effects in the Excited State Spin Populations of Mn-Doped Hybrid Perovskites.

Spin-orbit coupling in the electronic states of solution-processed hybrid metal halide perovskites forms complex spin-textures in the band structures and allows for optical manipulation of the excited state spin-polarizations. Here, we report that motional narrowing acts on the photoexcited spin-polarization in CH3NH3PbBr3 thin films, which are doped at percentage-level with Mn2+ ions. Using ultrafast circularly polarized broadband transient absorption spectroscopy at cryogenic temperatures, we investigate the spin population dynamics in these doped hybrid perovskites and find that spin relaxation lifetimes are increased by a factor of 3 compared to those of undoped materials. Using quantitative analysis of the photoexcitation cooling processes, we reveal increased carrier scattering rates in the doped perovskites as the fundamental mechanism driving spin-polarization-maintaining motional narrowing. Our work reports transition-metal doping as a concept to extend spin lifetimes of hybrid perovskites.

Field induced spin freezing and low temperature heat capacity of disordered pyrochlore oxide Ho2Zr2O7.

Spin ice materials are the model systems that have a zero-point entropy as T ! 0 K, owing to the frozen disordered states. Here, we chemically alter the well-known spin ice Ho2Ti2O7 by replacing Ti sites with isovalent but larger Zr ion. Unlike the Ho2Ti2O7 which is a pyrochlore material, Ho2Zr2O7 crystallizes in disordered pyrochlore structure. We have performed detailed structural, ac magnetic susceptibility and heat capacity studies on Ho2Zr2O7 to investigate the interplay of structural disorder and frustrated interactions. The zero-field ground state exhibits large magnetic susceptibility and remains dynamic down to 300 mK without showing Pauling's residual entropy. The dynamic state is suppressed continuously with the magnetic field and freezing transition evolves ( 10 K) at a field of 10 kOe. These results suggest that the alteration of chemical order and local strain in Ho2Ti2O7 prevents the development of spin ice state and provides a new material to study the geometrical frustration based on the structure.

Association of serum zinc level and clinical outcome in Egyptian COVID-19 patients.

Background: Zinc is an anti-inflammatory and antioxidant micronutrient found in food. Due to its well-established role in immunity, it is currently being used in some clinical trials against coronavirus disease-2019 (COVID-19). This study aimed to assess the association between the mean serum zinc level in COVID-19 Egyptian patients and its relationship with disease severity. This cross-sectional study was conducted on sixty patients with confirmed COVID-19 infection. These patients were divided into two groups according to clinical outcome, group 1 which included 30 intensive care unit (ICU) patients and group 2 which included 30 patients who were admitted to the ward. Mean serum levels of zinc were compared between the two groups. Results: There was a statistically significant difference noted among study groups regarding the serum zinc level (p < 0.039), where lower mean serum zinc levels were noted in ICU patients compared to ward patients (70.6 ± 5.7 vs 73.8 ± 6.1). Conclusion: Low serum zinc level is associated with the severe outcome of COVID-19 infection.

Assessment of fibroblast growth factor 19 as a non-invasive serum marker for hepatocellular carcinoma.

BACKGROUND: Fibroblast growth factor 19 (FGF-19) is one of the founding members of the endocrine FGF subfamily. Recently, it has been the subject of much interest owing to its role in various physiological processes affecting glucose and lipid metabolism and the regulation of bile acid secretion as well as cell proliferation, differentiation, and motility. Additionally, FGF-19 secretion in an autocrine style has reportedly contributed to cancer progression in various types of malignancies including hepatocellular carcinoma (HCC). AIM: To estimate the serum FGF-19 concentrations in HCC cases and assess its diagnostic performance for the detection of HCC. METHODS: We recruited 90 adult participants and divided them into three equal groups: Healthy controls, cirrhosis patients, and HCC patients. Serum FGF-19 concentrations were measured using the Human FGF-19 ELISA kit. RESULTS: We detected a high statistically significant difference in serum FGF-19 levels among the three groups. The highest level was observed in the HCC group, followed by the cirrhosis and control groups (236.44 ± 40.94 vs 125.63 ± 31.54 vs 69.60 ± 20.90 pg/mL, respectively, P ≤ 0.001). FGF-19 was positively correlated with alpha fetoprotein (AFP; r = 0.383, P = 0.003) and international normalised ratio (r = 0.357, P = 0.005), while it was negatively correlated with albumin (r = -0.500, P ≤ 0.001). For the detection of HCC, receiver operating characteristic curve analysis showed that the best cut-off point of AFP was > 8.2 ng/mL with an area under the curve (AUC) of 0.78, sensitivity of 63.33%, specificity of 83.33%, positive predictive value (PPV) of 79.2%, negative predictive value (NPV) of 69.4%, and total accuracy of 78%. However, FGF-19 at a cut-off point > 180 pg/mL had an AUC of 0.98, sensitivity of 100%, specificity of 90.0%, PPV of 90.0%, NPV of 100%, and total accuracy of 98%. CONCLUSION: FGF-19 represents a possible novel non-invasive marker for HCC. It may improve the prognosis of HCC patients due to its utility in several aspects of HCC detection and management.

Role of Thymosin Beta 4 in the diagnosis of Nonalcoholic Fatty Liver and its relation to Metabolic Syndrome in Egyptian patients.

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of hepatic diseases linked to metabolic and cardiovascular disorders that impair quality of life and increase morbidity and mortality. There has been significant interest in replacing conventional diagnostic tools such as liver biopsy with non-invasive biomarkers for the diagnosis of NAFLD. Thymosin Beta 4 (Tß4) is a G-actin sequestering peptide involved in many critical biological processes. This study aimed to evaluate the role of Tß4 in the diagnosis of NAFLD, and its relation to metabolic syndrome. Eighty patients were enrolled in this study, divided into two equal groups of NAFLD cases (n=40) and a control group (n=40). The two groups were subjected to history taking, physical examination, measurement of waist circumference and body mass index (BMI). Laboratory workup included serum Tß4, insulin resistance (HOMA-IR), fibrosis-4 score (FIB-4), fatty liver index (FLI) and NAFLD fibrosis score (NFL) were calculated for both groups. Serum Tß4 was significantly lower in NAFLD patients (P < 0.001) and there was a significant positive correlation between serum Tß4 and HDL (P = 0.034). On the other hand, there was a significant negative correlation between serum Tß4 and waist circumference (P < 0.001), total cholesterol level (P < 0.001), insulin level (P < 0.001), HOMA-IR (P < 0.001), serum triglycerides (P= 0.025) and FLI (P = 0.004). Serum Tß4 at a cut-off value of ≤900 ng/ml had 100 % sensitivity, 100 % specificity, 100% positive predictive value and 100% negative predictive value for the prediction of NAFLD. In conclusion, serum Tß4 could be used as a biomarker for the diagnosis of NAFLD.

Impact of different processing methods on the phenolics and neuroprotective activity of Fragaria ananassa Duch. extracts in a D-galactose and aluminum chloride-induced rat model of aging.

Age-related diseases, including dementia, are a major health concern affecting daily human life. Strawberry (Fragaria ananassa Duch.) is the most eaten fruit worldwide due to its exceptional aroma and flavor. However, it's rapid softening and decay limit its shelf-life. Freezing and boiling represent the well-known conservation methods to extend its shelf-life. Therefore, we aimed to discover the phytochemical content differences of fresh and processed strawberries associated with investigating and comparing their neuroprotective effects in a rat model of aging. Female Wistar rats were orally pretreated with fresh, boiled, and frozen F. ananassa methanolic extracts (250 mg kg-1) for 2 weeks, and then these extracts were concomitantly exposed to D-galactose [65 mg kg-1, subcutaneously (S/C)] and AlCl3 (200 mg kg-1, orally) for 6 weeks to develop aging-like symptoms. The results of UPLC/ESI-MS phytochemical profiling revealed 36 secondary metabolites, including phenolics, flavonoids, and their glycoside derivatives. Compared with boiled and frozen extracts, the fresh extract ameliorated the behavioral deficits including anxiety and cognitive dysfunction, upregulated brain HO-1 and Nrf2 levels, and markedly reduced caspase-3 and PPAR-γ levels. Moreover, LDH and miRNA-9, 124 and 132 protein expressions were reduced. The histological architecture of the brain hippocampus was restored and glial fibrillary acidic protein (GFAP) immunoexpression was downregulated. In conclusion, the fresh extract has neuroprotective activity that could have a promising role in ameliorating age-related neurodegeneration.

Talin-1; other than a potential marker for hepatocellular carcinoma diagnosis.

BACKGROUND AND STUDY AIMS: Hepatocellular carcinoma (HCC) is a major cause of cancer mortality worldwide. Talin-1 was previously proposed as a potential novel biomarker for HCC diagnosis but with limited and inconsistent data. We aimed to study the possible role of talin-1 in diagnosis and prognostic stratification of patients with hepatocellular carcinoma. PATIENTS AND METHODS: Ninety-six patients were recruited and classified into three groups; 1) cirrhosis group: 40 patients with liver cirrhosis, 2) HCC group: 40 patients with HCC, 3) control group: 16 healthy volunteers with matched age and sex. Serum talin-1 level was detected using enzyme-linked immunosorbent assay (ELISA). RESULTS: The highest levels of talin-1 were observed among the HCC group followed by cirrhosis then control groups (p = 0.000). In the HCC group, a significant correlation was found between talin-1 and each of multifocal HCC (p = 0.013), portal vein invasion (p = 0.022) and presence of ascites (p = 0.001), while no significant correlation was detected with tumour foci size (p = 0.605). For HCC detection, talin-1 had AUC = 0.858, 100% sensitivity and 65% specificity, while AFP had AUC = 1.000, 100% sensitivity and specificity. CONCLUSION: Talin-1 is a potential marker for diagnosis and prognostic assessment of HCC. Further studies are needed to investigate the ultimate diagnostic and prognostic utility of serum talin-1.

Adsorption of Cd2+ and Cr3+ ions from aqueous solutions by using residue of Padina gymnospora waste as promising low-cost adsorbent.

Recently, a great attention has been given for applying a low-cost and effective adsorbents instead of expensive and dangerous chemical materials as a promising approach to treat wastewater. In this work, residue powder of brown macroalga Padina gymnospora (RPG), after extracting most of its active components by 70% methanol, was used as an adsorbent material for wastewater treatment. This work also reduces the costs of residue disposal. The adsorption ability of RPG is studied for removing Cd2+ and Cr3+from wastewater. We investigated metal adsorption isotherms and kinetics, the effect of initial metal concentration, contact time, adsorbent dosage, temperature, pH and the RPG reusability on metal ions removal. The results showed that the removal % generally increases with decreasing concentration of metal ions. RPG has higher metal removal percentages reaching 96.2% and 78.8% for Cd2+ and Cr3+, respectively, with a maxiumum adsorption capacity of 96.46 and 31.52 mg/g for Cd 2+ and Cr3+,respectively at pH 6.2, 50 mg, 25 °C and initial metal concentration of 100 mg/L. The metal ions removal % increased by increasing the dosage of adsorbent and it decreased after a certain limit. The metal removal % slightly changes with increasing temperature for Cd2+ and decreased at high-temperature for Cr3+. The adsorption increased with increasing pH value from 3 to 5, and decreases at pH value of 6.2 then it increased again at pH 8. The removal % and adsorption capacity at pH 8 reaches 99.58%, 99.65%, 99.85 mg/g and 39.86 mg/g for Cd2+ and Cr3+, respectively. The results also showed that RPG can be reused several times for metal ions removal. In addition, Tempkin isotherms and pseudo-second-order kinetic fit the adsorption of Cd2+ and Cr3+ well.