Synthesis and Characterization of Zno Nanoparticles Using Hydrothermal and Sol-Gel Techniques for Dye-Sensitized Solar Cells

في هذا البحث تم تخليق جسيمات نانوية نقية من أكسيد الزنك باستخدام طريقتي الهيدروثيرمال وطريقة الصول جل. من فحوصات حيود الاشعة السينية تبين أن متوسط حجم الحبيبة تتراوح بين من 25 الي 28 نانومتر وتاخذ شكلا كرويا. فحوصات طيف الامتصاص بينت أن العينات جميعها لها اعلي امتصاص في منطقة الاشعة الفوق بنفسجية. وتم حساب فجوة الطاقة للعينات فوجد انها تساوي 3.13 eV و3.16 eV للعينة التي حضرت بطريقة الهيدروثيرمال والصول جل على الترتيب. تم تحضير عينات لخلايا شمسية صبغية وتم استخدام 3 انواع من الاصباغ الكيمياءية كمتحسسات ضوئية. فحوصات الاشعة الفوق بنفسجية بينت ان صبغة الايوزين الاصفر   Eosin Yتعطي اعلي امتصاص مقارنة بالاصباغ المستخدمة الاخري. تم رسم منحني الخواص لجميع العينات للخلايا الشمسية المحضرة وتم حساب جميع البارامترات اللازمة لتقييم اداء الخلية. العينة المصبوغة بصبغةEosin Y اعطت اعلي كفاءة Jsc = 4.25 (mA/cm2)، Voc = 0.51 V and η=1.08 %ZnO nanoparticles (ZnO NPs) were synthesized using hydrothermal and sol-gel techniques using zinc acetate dihydrate (Zn (CH3COO)2.2H2O) as a row material and methanol as a solvent. The structural properties of ZnO NPs were studied using EDX, XRD, TEM, and the optical properties were characterized using UV-VIS and PL spectroscopies. The synthesized ZnO NPs showed high purity and revealed a wurtzite (hexagonal) crystal structure with particle size (D) ranged from 25 nm to 28 nm. The UV-VIS absorption spectra of ZnO NPs samples and sensitizing dyes were performed. The obtained ZnO NPs exhibited the direct optical bandgap 3.15 eV. Dye-sensitized solar cells (DSSCs) were fabricated using synthesized ZnO NPs as a semiconducting layer, which was dyed with different low cost dyes such as Eosin B (EB), Eosin Y (EY) and Rhodamine B (RB) that was used to sensitize the photoanode (ZnO NPs). The experimental results showed a significant efficiency for the fabricated DSSCs of synthesized ZnO NPs via sol gel technique comparing to hydrothermal technique. The EY dye exhibited the best performance among others, where a conversion efficiency showed a noteworthy improvement from 0.12 to 1.08 %

Synthesis and characterization of ZnO nanoparticles using sol gel technique for dye sensitized solar cells applications

ZnO nanoparticles were synthesized using sol gel technique at differentcalcination temperature. The effect of calcination temperature on the structure and opticalproperties of ZnO NPs were studied in detail by using different techniques, X-raydiffraction, high-resolution transmission electron microscope, UV-VIS spectroscopy andphotoluminescence spectroscopy.X-ray diffractionanalysis revealed that the ZnO NPs werecrystalized in a wurtzite structure and the estimated average particle size increased from24.7 to40.4 nm with increasingcalcinationtemperature. In addition, the d spacingincreased from 0.28196 nm to 0.28213 nm.High-resolution transmission electronmicroscopy analysisimage showed spherical ZnONPs were formed. UV-VIS absorptionmeasurement was employed to evaluate the absorption edge and the optical band gapusingTauc plot. Energy gaprevealed a red shift from 3.15 to 2.96 eV when thecalcinationtemperaturewas increased. Dye sensitized solar cells were fabricated using synthesizedZnO NPs as a semiconducting layer that were dyed withdifferentXanthene(CH2[C6H4]2O)dyesseparately;(Eosin B, Eosin Y and Rhodamine B) which arelow costdyes. Thin layer of ZnO were deposited on transparentfluorine doped tin oxideconductiveglass using doctor blade method. Eosin Y exhibited the bestphotosensitizing. Theconversion efficiency showed a significant improvement from 0.1% to 1.08%.This research activity carried out between Gaza-Palestine and Cairo-Egypt, which was financially supported by Qatar Charity IBHATH Project grant funded by the Gulf Cooperation Council for the Reconstruction of Gaza through the Islamic Development Bank.ZnO nanoparticles were synthesized using sol gel technique at differentcalcination temperature. The effect of calcination temperature on the structure and opticalproperties of ZnO NPs were studied in detail by using different techniques, X-raydiffraction, high-resolution transmission electron microscope, UV-VIS spectroscopy andphotoluminescence spectroscopy.X-ray diffractionanalysis revealed that the ZnO NPs werecrystalized in a wurtzite structure and the estimated average particle size increased from24.7 to40.4 nm with increasingcalcinationtemperature. In addition, the d spacingincreased from 0.28196 nm to 0.28213 nm.High-resolution transmission electronmicroscopy analysisimage showed spherical ZnONPs were formed. UV-VIS absorptionmeasurement was employed to evaluate the absorption edge and the optical band gapusingTauc plot. Energy gaprevealed a red shift from 3.15 to 2.96 eV when thecalcinationtemperaturewas increased. Dye sensitized solar cells were fabricated using synthesizedZnO NPs as a semiconducting layer that were dyed withdifferentXanthene(CH2[C6H4]2O)dyesseparately;(Eosin B, Eosin Y and Rhodamine B) which arelow costdyes. Thin layer of ZnO were deposited on transparentfluorine doped tin oxideconductiveglass using doctor blade method. Eosin Y exhibited the bestphotosensitizing. Theconversion efficiency showed a significant improvement from 0.1% to 1.08%

Association of Six Single Nucleotide Polymorphisms with Gestational Diabetes Mellitus in a Chinese Population

To investigate whether the candidate genes that confer susceptibility to type 2 diabetes mellitus are also correlated with gestational diabetes mellitus (GDM) in pregnant Chinese women.In this study, 1764 unrelated pregnant women were recruited, of which 725 women had GDM and 1039 served as controls. Six single nucleotide polymorphisms (rs7754840 in CDKAL1, rs391300 in SRR, rs2383208 in CDKN2A/2B, rs4402960 in IGF2BP2, rs10830963 in MTNR1B, rs4607517 in GCK) were genotyped using TaqMan allelic discrimination assays. The genotype and allele distributions of each SNP between the GDM cases and controls and the combined effects of alleles for the risk of developing GDM were analyzed. We found that the rs4402960, rs2383208 and rs391300 were statistically associated with GDM (OR = 1.207, 95%CI = 1.029-1.417, p = 0.021; OR = 1.242, 95%CI = 1.077-1.432, p = 0.003; OR = 1.202, 95%CI = 1.020-1.416, P = 0.028, respectively). In addition, the effect was greater under a recessive model in rs391300 (OR = 1.820, 95%CI = 1.226-2.701, p = 0.003). Meanwhile, the joint effect of these three loci indicated an additive effect of multiple alleles on the risk of developing GDM with an OR of 1.196 per allele (p = 1.08×10(-4)). We also found that the risk alleles of rs2383208 (b = -0.085, p = 0.003), rs4402960 (b = -0.057, p = 0.046) and rs10830963 (b = -0.096, p = 0.001) were associated with HOMA-B, while rs7754840 was associated with decrease in insulin AUC during a 100 g OGTT given at the time of GDM diagnosis (b = -0.080, p = 0.007).Several risk alleles of type 2 diabetes were associated with GDM in pregnant Chinese women. The effects of these SNPs on GDM might be through the impairment of beta cell function and these risk loci contributed additively to the disease

Novel subgroups of adult-onset diabetes and their association with outcomes : a data-driven cluster analysis of six variables

Background Diabetes is presently classified into two main forms, type 1 and type 2 diabetes, but type 2 diabetes in particular is highly heterogeneous. A refined classification could provide a powerful tool to individualise treatment regimens and identify individuals with increased risk of complications at diagnosis. Methods We did data-driven cluster analysis (k-means and hierarchical clustering) in patients with newly diagnosed diabetes (n=8980) from the Swedish All New Diabetics in Scania cohort. Clusters were based on six variables (glutamate decarboxylase antibodies, age at diagnosis, BMI, HbA(1c), and homoeostatic model assessment 2 estimates of beta-cell function and insulin resistance), and were related to prospective data from patient records on development of complications and prescription of medication. Replication was done in three independent cohorts: the Scania Diabetes Registry (n=1466), All New Diabetics in Uppsala (n=844), and Diabetes Registry Vaasa (n=3485). Cox regression and logistic regression were used to compare time to medication, time to reaching the treatment goal, and risk of diabetic complications and genetic associations. Findings We identified five replicable clusters of patients with diabetes, which had significantly different patient characteristics and risk of diabetic complications. In particular, individuals in cluster 3 (most resistant to insulin) had significantly higher risk of diabetic kidney disease than individuals in clusters 4 and 5, but had been prescribed similar diabetes treatment. Cluster 2 (insulin deficient) had the highest risk of retinopathy. In support of the clustering, genetic associations in the clusters differed from those seen in traditional type 2 diabetes. Interpretation We stratified patients into five subgroups with differing disease progression and risk of diabetic complications. This new substratification might eventually help to tailor and target early treatment to patients who would benefit most, thereby representing a first step towards precision medicine in diabetes.Peer reviewe

Association of Genetic Variants of Melatonin Receptor 1B with Gestational Plasma Glucose Level and Risk of Glucose Intolerance in Pregnant Chinese Women

BACKGROUND: This study aimed to explore the association of MTNR1B genetic variants with gestational plasma glucose homeostasis in pregnant Chinese women. METHODS: A total of 1,985 pregnant Han Chinese women were recruited and evaluated for gestational glucose tolerance status with a two-step approach. The four MTNR1B variants rs10830963, rs1387153, rs1447352, and rs2166706 which had been reported to associate with glucose levels in general non-pregnant populations, were genotyped in these women. Using an additive model adjusted for age and body mass index (BMI), association of these variants with gestational fasting and postprandial plasma glucose (FPG and PPG) levels were analyzed by multiple linear regression; relative risk of developing gestational glucose intolerance was calculated by logistic regression. Hardy-Weinberg Equilibrium was tested by Chi-square and linkage disequilibrium (LD) between these variants was estimated by measures of D' and r(2). RESULTS: In the pregnant Chinese women, the MTNR1B variant rs10830963, rs1387153, rs2166706 and rs1447352 were shown to be associated with the increased 1 hour PPG level (p=8.04 × 10(-10), 5.49 × 10(-6), 1.89 × 10(-5) and 0.02, respectively). The alleles were also shown to be associated with gestational glucose intolerance with odds ratios (OR) of 1.64 (p=8.03 × 10(-11)), 1.43 (p=1.94 × 10(-6)), 1.38 (p=1.63 × 10(-5)) and 1.24 (p=0.007), respectively. MTNR1B rs1387153, rs2166706 were shown to be associated with gestational FPG levels (p=0.04). Our data also suggested that, the LD pattern of these variants in the studied women conformed to that in the general populations: rs1387153 and rs2166706 were in high LD, they linked moderately with rs10830963, but might not linked with rs1447352;rs10830963 might not link with rs1447352, either. In addition, the MTNR1B variants were not found to be associated with any other traits tested. CONCLUSIONS: The MTNR1B is likely to be involved in the regulation of glucose homeostasis during pregnancy

A thermosensitive electromechanical model for detecting biological particles

Miniature electromechanical systems form a class of bioMEMS that can provide appropriate sensitivity. In this research, a thermo-electro-mechanical model is presented to detect biological particles in the microscale. Identification in the model is based on analyzing pull-in instability parameters and frequency shifts. Here, governing equations are derived via the extended Hamilton’s principle. The coupled effects of system parameters such as surface layer energy, electric field correction, and material properties are incorporated in this thermosensitive model. Afterward, the accuracy of the present model and obtained results are validated with experimental, analytical, and numerical data for several cases. Performing a parametric study reveals that mechanical properties of biosensors can significantly affect the detection sensitivity of actuated ultra-small detectors and should be taken into account. Furthermore, it is shown that the number or dimension of deposited particles on the sensing zone can be estimated by investigating the changes in the threshold voltage, electrode deflection, and frequency shifts. The present analysis is likely to provide pertinent guidelines to design thermal switches and miniature detectors with the desired performance. The developed biosensor is more appropriate to detect and characterize viruses in samples with different temperatures

Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years