Synthesis, structural and morphological characterizations of nano-Ru-based perovskites/RGO composites

Highly-dispersed Ru-based perovskites supported on reduced graphene oxide (A-RG) nanocomposites are prepared using different A-metal salts (Sr(NO₃)₂, Ba(NO₃)₂ and Ca(NO₃)₂). The procedure is based on a redox reaction between the metal precursors and graphene oxide (GO) using two different routes of reaction initiation: through thermal heating or by microwave-assisted heating. The resulting nanocomposites do not require further calcination, making this method less energy-demanding. In addition, no additional chemical reagents are required for either the GO reduction or the metal precursor oxidation, leading to an overall simple and direct synthesis method. The structure and morphology of the as-prepared A-RG (non-calcined) nanocomposites are characterized using various structural analyses including XRD, XPS, SEM/EDX and HR-TEM. Changing metal A in the perovskite as well as the “activation method” resulted in significant structural and morphological changes of the formed composites. SrRuO₃ and BaRuO₃ in combination with RuO₂ are obtained using a conventional combustion method, while SrRuO₃ (~1 nm size) in combination with Ru nanoparticles are successfully prepared using microwave irradiation. For the first time, a microwave-assisted synthesis method (without calcination) was used to form crystalline nano-CaRuO₃

Serum selenoprotein P in lean and obese Egyptian individuals and its relation to insulin resistance

Background: Obesity is a major health problem with increasing prevalence and directly contributes to the development of cardiovascular disease (CVD). Selenoprotein P (Se P) is a novel hepatokine that affects glucose metabolism, lipid metabolism, and correlating with insulin resistance, inflammation, and atherosclerosis. Plasma Se P level is one of the promising biomarkers for predictions or diagnoses/prognoses of the diseases.Objective: Evaluating the serum level of Selenoprotein P in overweight, obese, and lean individuals and its relation to insulin resistance and cardiometabolic parameters.Subjects and Methods: A cross-sectional study was conducted in the Outpatient Endocrinology Clinics, Internal Medicine Department, Menoufia University Hospitals on 90 individuals that were divided into two groups: (group I) 50 overweight and obese individuals (with body mass index (BMI) in the range 25.0–29.9 kg/m2 and ≥30.0 kg/m2, respectively) and (group II) 40 lean individuals with BMI in the range (18.5–24.9) kg/m2. All subjects were subjected to detailed history taking, clinical examination, and laboratory investigations including fasting and 2 hours postprandial blood sugar, lipid profile, fasting serum insulin level, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and serum Se P.Results: Se P concentrations were significantly increased in overweight and obese group than lean group (p < 0.001). Se P concentration was related to various cardio-metabolic parameters. In overweight and obese group there was a significant positive correlation between serum Selenoprotein p level and waist circumference (WC) (r −0.453, p <0.001), hip circumference (HC) (r = 0.464, p < 0.001), waist-hip ratio (WHR) (r −0.506, p < 0.001), visceral adiposity index (VAI) (r = 0.323, p = 0.022), fasting serum insulin (r = 0.585, p < 0.001), and HOMA-IR (r = 0.570, p < 0.001).Conclusion: Circulating Se P concentrations is elevated in obesity and related to insulin resistance, visceral adiposity, and atherogenic index of plasma

Breast lesions and cancer: histopathology and molecular classification in a referral hospital in Ghana

Background: Histological diagnosis is crucial to the management of breast diseases. It determines the kind of disease, the treatment modalities, and the outcome of management. Our department receives breast biopsies from the northern sector of Ghana constituting over 50% of the Ghanaian population. This study aimed at elucidating the pattern of disease and associated traditional prognostic indices of breast cases in our department over a period of 9 years.Methods: Information on the demographic characteristics and the histological diagnoses made on all breast cases received and processed in the department were accessed and entered into an Excel spreadsheet. Slides were reviewed and IHC was done on suitable cases. Descriptive statistics were generated using IMB-SPSS version 23.Results: A total of 4276 breast cases were received by the department within the study period, with 97.6% being female. Age ranged (female/male) from 10 to 98/13 to 102 years, with mean ages of 38.2 years (SD ± 16.7) and 41.15 years (SD ± 21.6), respectively. Cases were evenly distributed in both left and right breasts and 4.3% were bilateral. Inflammatory conditions were seen in 7.5% of cases. The most diagnosed benign tumor was fibroadenoma (54%), followed by fibrocystic change (8.1%). Gynecomastia was diagnosed in 66.3% of males. Malignant cases were 38.6%, with invasive carcinoma NST being the most frequent (87.5%). Histological grades were I = 9.4%, II = 41.6%, and III = 49%. Molecular subtypes were luminal A (19.8%), luminal B (9.9%), Her2 (16%), and TNBC (54.3%).Conclusion: Our findings show an increase in breast cancer cases compared to previous studies in our center, suggesting increased awareness and improved diagnosis. However, this increase is consistent with most studies in sub-Saharan Africa

A guide to best practice in faculty development for health professions schools: a qualitative analysis

BACKGROUND: This is a practice guide for the evaluation tool specifically created to objectively evaluate longitudinal faculty development programs (FDP) using the “5×2 -D backward planning faculty development model”. It was necessary to create this tool as existing evaluation methods are designed to evaluate linear faculty development models with a specific endpoint. This backward planning approach is a cyclical model without an endpoint, consisting of 5 dynamic steps that are flexible and interchangeable, therefore can be a base for an evaluation tool that is objective and takes into account all the domains of the FDP in contrast to the existing, traditional, linear evaluation tools which focus on individual aspects of the program. The developed tool will target evaluation of longitudinal faculty development programs regardless of how they were planned. METHODOLOGY: Deductive qualitative grounded theory approach was used. Evaluation questions were generated and tailored based on the 5 × 2-D model followed by 2 Delphi rounds to finalize them. Based on the finalized evaluation questions from the results of the Delphi rounds, two online focus group discussions (FGDs) were conducted to deduce the indicators, data sources and data collection method. RESULTS: Based on the suggested additions, the authors added 1 new question to domains B, with a total of 42 modifications, such as wording changes or discarding or merging questions. Some domains received no comments, therefore, were not included in round 2. For each evaluation question, authors generated indicators, data sources and data collection methods during the FGD. CONCLUSION: The methodology used to develop this tool takes into account expert opinions. Comprehensiveness of this tool makes it an ideal evaluation tool during self-evaluation or external quality assurance for longitudinal FDP. After its validation and testing, this practice guide can be used worldwide, along with the provided indicators which can be quantified and used to suit the local context. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12909-022-03208-x

Atomistic modeling of amorphous silicon carbide: An approximate first-principles study in constrained solution space

Localized basis ab initio molecular dynamics simulation within the density functional framework has been used to generate realistic configurations of amorphous silicon carbide (a-SiC). Our approach consists of constructing a set of smart initial configurations that conform essential geometrical and structural aspects of the materials obtained from experimental data, which is subsequently driven via first-principles force-field to obtain the best solution in a reduced solution space. A combination of a priori information (primarily structural and topological) along with the ab-initio optimization of the total energy makes it possible to model large system size (1000 atoms) without compromising the quantum mechanical accuracy of the force-field to describe the complex bonding chemistry of Si and C. The structural, electronic and the vibrational properties of the models have been studied and compared to existing theoretical models and available data from experiments. We demonstrate that the approach is capable of producing large, realistic configurations of a-SiC from first-principles simulation that display excellent structural and electronic properties of a-SiC. Our study reveals the presence of predominant short-range order in the material originating from heteronuclear Si-C bonds with coordination defect concentration as small as 5% and the chemical disorder parameter of about 8%.Comment: 16 pages, 7 figure

To what extent can dynamical models describe statistical features of turbulent flows?

Statistical features of "bursty" behaviour in charged and neutral fluid turbulence, are compared to statistics of intermittent events in a GOY shell model, and avalanches in different models of Self Organized Criticality (SOC). It is found that inter-burst times show a power law distribution for turbulent samples and for the shell model, a property which is shared only in a particular case of the running sandpile model. The breakdown of self-similarity generated by isolated events observed in the turbulent samples, is well reproduced by the shell model, while it is absent in all SOC models considered. On this base, we conclude that SOC models are not adequate to mimic fluid turbulence, while the GOY shell model constitutes a better candidate to describe the gross features of turbulence.Comment: 14 pages, 4 figures, in press on Europhys. Lett. (may 2002

Transitions and Probes in Turbulent Helium

Previous analysis of a Paris turbulence experiment \cite{zoc94,tab95} shows a transition at the Taylor Reynolds number \rel \approx 700. Here correlation function data is analyzed which gives further evidence for this transition. It is seen in both the power spectrum and in structure function measurements. Two possible explanations may be offered for this observed transition: that it is intrinsic to the turbulence flow in this closed box experiment or that it is an effect of a change in the flow around the anemometer. We particularly examine a pair of ``probe effects''. The first is a thermal boundary layer which does exist about the probe and does limit the probe response, particularly at high frequencies. Arguments based on simulations of the response and upon observations of dissipation suggests that this effect is only crucial beyond \rel\approx 2000. The second effect is produced by vortex shedding behind the probe. This has been seen to produce a large modification in some of the power spectra for large \rel. It might also complicate the interpretation of the experimental results. However, there seems to be a remaining range of data for \rel < 1300 uncomplicated by these effects, and which are thus suggestive of an intrinsic transition.Comment: uuencoded .ps files. submitted to PRE. 12 figures are sent upon request to jane wang ([email protected]

Systematic Study of Electron Localization in an Amorphous Semiconductor

We investigate the electronic structure of gap and band tail states in amorphous silicon. Starting with two 216-atom models of amorphous silicon with defect concentration close to the experiments, we systematically study the dependence of electron localization on basis set, density functional and spin polarization using the first principles density functional code Siesta. We briefly compare three different schemes for characterizing localization: information entropy, inverse participation ratio and spatial variance. Our results show that to accurately describe defect structures within self consistent density functional theory, a rich basis set is necessary. Our study revealed that the localization of the wave function associated with the defect states decreases with larger basis sets and there is some enhancement of localization from GGA relative to LDA. Spin localization results obtained via LSDA calculations, are in reasonable agreement with experiment and with previous LSDA calculations on a-Si:H models.Comment: 16 pages, 11 Postscript figures, To appear in Phys. Rev.

Variable pulmonary manifestations in Chitayat syndrome: Six additional affected individuals

Hand hyperphalangism leading to shortened index fingers with ulnar deviation, hallux valgus, mild facial dysmorphism and respiratory compromise requiring assisted ventilation are the key features of Chitayat syndrome. This condition results from the recurrent heterozygous missense variant NM_006494.2:c.266A>G; p.(Tyr89Cys) in ERF on chromosome 19q13.2, encoding the ETS2 repressor factor (ERF) protein. The pathomechanism of Chitayat syndrome is unknown. To date, seven individuals with Chitayat syndrome and the recurrent pathogenic ERF variant have been reported in the literature. Here, we describe six additional individuals, among them only one presenting with a history of assisted ventilation, and the remaining presenting with variable pulmonary phenotypes, including one individual without any obvious pulmonary manifestations. Our findings widen the phenotype spectrum caused by the recurrent pathogenic variant in ERF, underline Chitayat syndrome as a cause of isolated skeletal malformations and therefore contribute to the improvement of diagnostic strategies in individuals with hand hyperphalangism