Effect of stabilizer on optical band gap of ZnO and their performance in dye-sensitized solar cells

ABSTRACT. In dye-sensitized solar cells, transparent metal oxide working electrodes play a vital role in defining the power conversion efficiency. It was found that the size of nanoparticles influences the electrical, optical properties of these electrodes. Herein, we describe the synthesis of ZnO with zinc acetate dihydrate and different stabilizers (diethylamine and triethylamine) by using a modified solvothermal process. The obtained materials were characterized by XRD, SEM, EDX, TEM, HRTEM, UV-visible, FTIR, and Raman methods. The crystallite sizes for ZnO-1 and ZnO-2 samples were indexed as 39.0 and 40.5 nm for the highest peak intensity with diethylamine and triethylamine stabilizer, respectively. We examine the effect of stabilizers on the morphology, optical band gap, and photovoltaic performance of the prepared ZnO. We found that ZnO prepared using diethylamine stabilizer exhibiting significant efficiency of 1.45%, open-circuit voltage 0.454 V, short-circuit current density 2.128 mA/cm2, and 0.66 fill factor were achieved under 44 mW/cm2 illumination powers with dye-3.                 KEY WORDS: Dye-sensitized solar cells, ZnO, Band gap, Photovoltaic performance   Bull. Chem. Soc. Ethiop. 2022, 36(1), 209-222.                                                        DOI: https://dx.doi.org/10.4314/bcse.v36i1.17                                                     &nbsp

BCG scar formation and test results in two generations

Introduction: Considering that BCG injection in newborns is part of TB control program in Iran many years ago, we aimed to compare prevalence of childhood BCG vaccination scar with previous study and asses influence of household crowding on TST result. Aims: Considering that over time there is likely to reduce the immune response, two groups of subjects were selected among young and middle aged. Methods and Material: This cross sectional study was conducted in Zia Abad of Qazvin (a province of Iran) during year 2008. 261 participants randomly were selected (139 asymptomatic children (12-16 y) and 122 adults (40-50 y)). A questionnaire was used to obtain prior histories of BCG vaccination, known exposure to tuberculosis, prior acquired of TB, symptoms of TB disease and household crowding. BCG vaccine scar was ascertained and all participants were tested with 5TU-PPD. Reactions of 10 mm or more were considered positive. Statistical analysis used: Using student t test, chi square and Fisher's exact test, the collected data was analyzed. Results: BCG scar was observed in 78.4 of participant (91.4 children vs. 78.6 adults) which the difference was significant. Twenty three (16.5) of children and 24 (19.7) of adults had tuberculin reactivity of �10 mm. In children and parent groups, positivity of TST had significant direct association with presence of BCG scar and crowding. Conclusions: Most vaccinated children had a scar. Our results demonstrate that a TST applied after BCG vaccination usually produces a reaction of <10 mm. In addition, there is a significant relationship between the tuberculin reactivity and both presence of BCG scar and crowding among children and adult groups. © 2011, Shiraz E Medical Journal. All right reserved

Associations of Epigenetic methylation with vitamin D receptor level in Iraqi Gestational diabetes mellitus patients

Background :GDM (gestational diabetes mellitus) is a hazardous pregnancy situation that occurs when a pregnant woman who that have never had diabetes progresses to cause systemic hyperglycemia during their pregnancy.DNA methylation is an epigenetic mechanism it occurs in the vertebrate genomes and generates 5-methylcytosine by transferring a methyl group to the C5 position of cytosine. DNA methylation modulates gene expression by either attracting or preventing transcription factor(s) from binding to DNA.  Objective: The purpose of this study is to figure out the connection between VDR-gene promoter methylation in Iraqi GDM and its consequence on vitamin D levels. Materials and Methods: This investigation comprised 50 patients with GDM (Group 1) and 30 healthy pregnant individuals as controls (Group 2). Methylation was analyzed by extracted DNA using Bisulfite conversion and detected by a specific primer.  Results: The results of methylation effect on vitamin D3 expressed there were significant differences between methylated (25.74 ± 2.00) a percentage of 32(64.00%) of GDM samples compared with concentration (14.00±1.41) of methylated sample control at the percentage of observed results of methylation (1 (3.3%) at p-value (0.00) while the Un-methylated and partial methylate GDM samples did not produce any significant effect comparing with healthy controls. Conclusions: Due to the increased metabolic activity associated with pregnancy, it's imperative to keep glucose levels in balance. It is suspected that both genetic and epigenetic factors play a role in the development of GDM and that the underlying mechanisms are complex and alter over time. To create efficient treatments and preventative plans, a greater understanding of these mechanisms and how they affect GDM is needed

Charnley low-friction arthroplasty of the hip. Five to 25 years survivorship in a general hospital

<p>Abstract</p> <p>Background</p> <p>Some studies have raised the question about whether the good results obtained with the Charnley prosthesis could be replicated at general hospitals when it comes to the frequency of early complications and failure rates, both of which would be higher than those published by centres devoted to hip arthroplasties.</p> <p>Methods</p> <p>We reviewed the results of 404 Low Friction Arthroplasties of the hip implanted between 1976 and 1993 in a general hospital by general orthopaedic surgeons. For the survival analysis, the end-point chosen would be the chirurgical revision of any of the prosthetic components for whatever reason.</p> <p>Results</p> <p>The complications were 16 dislocations (4%), 14 deep infections (3.5%), 2 neurological injuries (0,5%) and 5 clinical deep venous thromboses (1.2%) (2 pulmonary embolisms). The survival rate at 25 years, both for stem and cup, was 83%. Survival was higher in those arthroplasties implanted in patients older than 60 years, with statistical significance.</p> <p>Conclusion</p> <p>Low Friction Arthroplasty undertaken at general hospitals by general orthopaedic surgeons feature similar outcomes to those found in centres devoted to hip surgery.</p

Population-Based Rates of Revision of Primary Total Hip Arthroplasty: A Systematic Review

Background: Most research on failure leading to revision total hip arthroplasty (THA) is reported from single centers. We searched PubMed between January 2000 and August 2010 to identify population- or community-based studies evaluating ten-year revision risks. We report ten-year revision risk using the Kaplan-Meier method, stratifying by age and fixation technique. Results: Thirteen papers met the inclusion criteria. Cemented prostheses had Kaplan-Meier estimates of revision-free implant survival of ten years ranging from 88 % to 95%; uncemented prostheses had Kaplan-Meier estimates from 80 % to 85%. Estimates ranged from 72 % to 86 % in patients less than 60 years old and from 90 to 96 % in older patients. Conclusion: Data reported from national registries suggest revision risks of 5 to 20 % ten years following primary THA. Revision risks are lower in older THA recipients. Uncemented implants may have higher ten-year rates of revision, regardless of age

Best practice for motor imagery: a systematic literature review on motor imagery training elements in five different disciplines

<p>Abstract</p> <p>Background</p> <p>The literature suggests a beneficial effect of motor imagery (MI) if combined with physical practice, but detailed descriptions of MI training session (MITS) elements and temporal parameters are lacking. The aim of this review was to identify the characteristics of a successful MITS and compare these for different disciplines, MI session types, task focus, age, gender and MI modification during intervention.</p> <p>Methods</p> <p>An extended systematic literature search using 24 databases was performed for five disciplines: Education, Medicine, Music, Psychology and Sports. References that described an MI intervention that focused on motor skills, performance or strength improvement were included. Information describing 17 MITS elements was extracted based on the PETTLEP (physical, environment, timing, task, learning, emotion, perspective) approach. Seven elements describing the MITS temporal parameters were calculated: study duration, intervention duration, MITS duration, total MITS count, MITS per week, MI trials per MITS and total MI training time.</p> <p>Results</p> <p>Both independent reviewers found 96% congruity, which was tested on a random sample of 20% of all references. After selection, 133 studies reporting 141 MI interventions were included. The locations of the MITS and position of the participants during MI were task-specific. Participants received acoustic detailed MI instructions, which were mostly standardised and live. During MI practice, participants kept their eyes closed. MI training was performed from an internal perspective with a kinaesthetic mode. Changes in MI content, duration and dosage were reported in 31 MI interventions. Familiarisation sessions before the start of the MI intervention were mentioned in 17 reports. MI interventions focused with decreasing relevance on motor-, cognitive- and strength-focused tasks. Average study intervention lasted 34 days, with participants practicing MI on average three times per week for 17 minutes, with 34 MI trials. Average total MI time was 178 minutes including 13 MITS. Reporting rate varied between 25.5% and 95.5%.</p> <p>Conclusions</p> <p>MITS elements of successful interventions were individual, supervised and non-directed sessions, added after physical practice. Successful design characteristics were dominant in the Psychology literature, in interventions focusing on motor and strength-related tasks, in interventions with participants aged 20 to 29 years old, and in MI interventions including participants of both genders. Systematic searching of the MI literature was constrained by the lack of a defined MeSH term.</p