Fabrication and characterization of NiCu/GO and NiCu/rGO nanocomposites for fuel cell application.

This study investigated the electrochemical behavior of NiCu, NiCu/GO, and NiCu/rGO nanocomposites designed by combining a modified Hummers' method and hydrothermal technique. The prepared nanocomposites are tested as electrocatalysts in direct alcohol oxidation fuel cells (DAFCs) to identify the role of GO and rGO as catalyst supports for the enhancement of the NiCu composite performance. The production of the NiCu/GO and NiCu/rGO composites was demonstrated by FTIR spectroscopy, EDX, and SEM analyses. In DAFCs experiments, NiCu/rGO has better catalytic activity than pure NiCu and NiCu/GO composites, whereas the use of rGO and GO as supports enhances the performance of NiCu by 468.2% and 377.7% in methanol and 255.6% and 105.9% in ethanol, respectively. The higher performance was caused by the increased density of active dots and the combined electronic effects in the designed catalysts. The stabilities of the catalysts and charge carriers' dynamics are studied using chronoamperometry and electrochemical impedance spectroscopy.

Detection of low-concentration heavy metal exploiting Tamm resonance in a porous TiO2 photonic crystal.

The detection of heavy metal ions, particularly Hg2+, has gained significant attention due to their severe adverse effects on human health and ecosystems. Conventional methods for monitoring these metals in freshwater often suffer from limitations in sensitivity, accuracy, and cost-effectiveness. This work introduces a novel heavy metal sensor based on Tamm resonance within a one-dimensional (1D) porous TiO2 photonic crystal structure. The sensor design includes a prism, a silver (Ag) layer, a cavity, and a ternary multilayer porous TiO2 layer. Reflectance spectra are analyzed using the transfer matrix method. A key aspect of this study is the optimization of sensor performance, which involves adjusting the thicknesses of all layers and the porosity of the multilayer porous TiO2. This optimization strategy is critical for achieving high sensitivity. The results demonstrate that the optimized sensor exhibits a high sensitivity of 0.045 nm ppm-1 for Hg2+ solutions. This sensitivity arises from the effective integration of Tamm resonance with the properties of the porous TiO2 photonic crystal. The proposed structure shows great potential for applications in heavy metal sensing, especially for detecting Hg2+ ion contamination in drinking water with high sensitivity and accuracy. In addition to its high performance, the photonic crystal sensor offers extended lifetime, rapid measurement capabilities, cost-effectiveness, and potential for integration into compact devices, making it a promising solution for environmental monitoring and water quality assessment.

Sensing of heavy metal Pb2+ ions in water utilizing the photonic structure of highly controlled hexagonal TiON/TiO2 nanotubes.

The detection of heavy metals in water, especially Pb2+ ions, is important due to their severe hazardous effects. To address this issue, a highly controlled hexagonal TiON/TiO2 heterostructure has been synthesized in this study. The fabrication process involved the utilization of atomic layer deposition and direct current sputtering techniques to deposit TiO2 and TiON layers onto a porous Al2O3 membrane used as a template. The resulting heterostructure exhibits a well-ordered hollow tube structure with a diameter of 345 nm and a length of 1.2 µm. The electrochemical sensing of Pb2+ ions in water is carried out using a cyclic voltammetry technique under both light and dark conditions. The concentration range for the Pb2+ ions ranges from 10-5 to 10-1 M. The sensitivity values obtained for the sensor are 1.0 × 10-6 in dark conditions and 1.0 × 10-4 in light conditions. The remarkable enhancement in sensitivity under light illumination can be attributed to the increased activity and electron transfer facilitated by the presence of light. The sensor demonstrates excellent reproducibility, highlighting its reliability and consistency. These findings suggest that the proposed sensor holds great promise for the detection of Pb2+ ions in water, thereby facilitating environmental monitoring, water quality assessment, and safety regulation across various industries. Furthermore, the eco-friendly and straightforward preparation techniques employed in its fabrication provide a significant advantage for practical and scalable implementation.

The impact of environmentally friendly supramolecular coordination polymers as carbon steel corrosion inhibitors in HCl solution: synthesis and characterization.

Two 3D-supramolecular coordination polymers (SCP1 & SCP2) have been synthesized and characterized by physicochemical and spectroscopic methods. In a solution of 1.0 M HCl, SCPs were used to prevent corrosion of carbon steel (CS). The inhibition productivity (%η) rises as the synthetic inhibitor dose rises, and the opposite is true as the temperature rises. The study was carried out using chemical (mass loss, ML) and electrochemical ( potentiodynamic polarization, PDP and electrochemical impedance microscopy, EIS) techniques, which showed %η reached to 93.1% and 92.5% for SCP1 & SCP2, respectively at 21 × 10-6 M, 25 °C. For the polarization results, SCPs behave as mixed-type inhibitors. With increasing doses of SCPs, the charge transfer resistance grew and the double layer's capacitance lowered. The creation of a monolayer on the surface of CS was demonstrated by the finding that the adsorption of SCPs on its surface followed the Henry adsorption isotherm. The parameters of thermodynamics were computed and explained. The physical adsorption of SCPs on the surface of CS is shown by the lowering values of free energy (∆Goads < - 20 kJ mol-1) and increasing the activation energy (E*a) values in presence of SCP1 & SCP2 than in their absence. Atomic force microscope (AFM) and scanning electron microscopy (SEM) demonstrated the development of a protective thin film of SCPs precipitated on the surface of CS. There is a strong matching between results obtained from experimental and theoretical studies. Results from each approach that was used were consistent.

A normalization model for repeated letters in social media hate speech text based on rules and spelling correction.

As social media booms, abusive online practices such as hate speech have unfortunately increased as well. As letters are often repeated in words used to construct social media messages, these types of words should be eliminated or reduced in number to enhance the efficacy of hate speech detection. Although multiple models have attempted to normalize out-of-vocabulary (OOV) words with repeated letters, they often fail to determine whether the in-vocabulary (IV) replacement words are correct or incorrect. Therefore, this study developed an improved model for normalizing OOV words with repeated letters by replacing them with correct in-vocabulary (IV) replacement words. The improved normalization model is an unsupervised method that does not require the use of a special dictionary or annotated data. It combines rule-based patterns of words with repeated letters and the SymSpell spelling correction algorithm to remove repeated letters within the words by multiple rules regarding the position of repeated letters in a word, be it at the beginning, middle, or end of the word and the repetition pattern. Two hate speech datasets were then used to assess performance. The proposed normalization model was able to decrease the percentage of OOV words to 8%. Its F1 score was also 9% and 13% higher than the models proposed by two extant studies. Therefore, the proposed normalization model performed better than the benchmark studies in replacing OOV words with the correct IV replacement and improved the performance of the detection model. As such, suitable rule-based patterns can be combined with spelling correction to develop a text normalization model to correctly replace words with repeated letters, which would, in turn, improve hate speech detection in texts.

Role of school teachers in identifying attention deficit hyperactivity disorder among primary school children in Mansoura, Egypt

There is a knowledge gap in primary school teachers that affects their ability to detect attention deficit hyperactivity disorder [ADHD]. This study measured primary school teachers' knowledge about ADHD, and implemented a training programme to improve early detection of ADHD. The prevalence and risk factors of ADHD were also studied. The training programme was implemented through a 2-day workshop for 39 primary school teachers who completed a validated Arabic version of the ADHD Rating Scale for 873 primary school children. The children's parents completed the questionnaire to explore ADHD risk factors. The teachers' pre-training knowledge scores of ADHD ranged from 17.9 to 46.2%. Post-training, their scores improved significantly to 69.2-94.9%. Prevalence rate of ADHD was 12.60%. On logistic regression, independent predictors of ADHD were female gender, unemployed fathers and rural residence. In conclusion, ADHD is a significant health problem among primary school children in Mansoura, Egypt. Efforts should be made to improve teachers' knowledge about ADHD and control modifiable risk factors

Il existe certaines lacunes en matière de connaissances des enseignants du primaire qui affecte leur capacité à détecter le trouble de déficit de l'attention avec hyperactivité [TDHA]. La présente étude a permis de mesurer les connaissances de ces enseignants à cet égard et de mettre en place un programme de formation visant à améliorer le dépistage précoce du TDAH. La prévalence et les facteurs de risque de ce trouble ont par ailleurs été examinés. Le programme de formation a été mis en place sous la forme d'un atelier de deux jours destiné à 39 enseignants du primaire qui ont réalisé une évaluation du TDAH pour 873 élèves du primaire en utilisant une version arabe validée de l'échelle. Les parents des élèves ont rempli un questionnaire visant à déterminer les facteurs de risque du TDAH. Les scores à l'échelle d'évaluation du TDAH portant sur la connaissance des enseignants avant la formation allaient de 17,9% à 46,2%, et affichaient une nette amélioration après formation [69,2% à 94,9%]. Le taux de prévalence du TDAH était de 12,60%. La régression logistique a révélé que les variables indépendantes étaient l'appartenance au sexe féminin, le chômage du père et la résidence en milieu rural. En conclusion, le TDAH représente un problème de santé important parmi les élèves du primaire à Mansoura, en Egypte. Des efforts doivent être déployés pour améliorer les connaissances des enseignants sur le TDAH et contrôler les facteurs de risque modifiables

Effect of Gestation and Season on the Haematological and Biochemical Parameters in Domestic Rabbit (Oryctolagus cuniculus).

The aim of this study was to investigate the effect of gestation and season on the haematological and biochemical parameters in domestic rabbit (Oryctolagus cuniculus) to improve the conditions of breeding and conservation in Saudi Arbia. For this study. 30 nonpregnant and 30 pregnant rabbits on day 24 to 26 of gestation were examined. The animals weighed between 2.6 and 3.6 kg and were 1.8-2.6 years old. Blood samples were collected from pregnant and non–pregnant rabbits in January (winter season), April (spring season), July (summer season) and October (autumn season) for analyzing hematological and biochemical parameters. It was revealed for the study that the value of hematological parameters i.e., erythrocyte, leukocyte, lymphocyte numbers and haemoglobin concentrations of pregnant rabbits were significantly (p<0.05) decreased compared with non-pregnant rabbit. Whereas, mean corpuscular volume was significantly (p<0.05) increased in pregnant rabbits compared with non-pregnant ones. The value of biochemical parameters i.e., total protein, albumin, triglyceride, cholesterol, calcium, and phosphorus were significantly (p<0.05) decreased in pregnant rabbits compared with non-pregnant. Whereas, glucose level was significantly (p<0.05) increased in pregnant rabbits compared with non-pregnant rabbits. Most of hematological parameters significantly (p<0.05) decreased in July. In contrast only few significant changes recorded in biochemical parameters. In conclusion, the rabbits suffer of heat stress during summer season and this causes deterioration in some, hematological constituents and biochemical parameters. These changes can be reflected on the activities, performance and fetus of pregnant rabbits under hot environmental conditions of Saudi Arabia. Hence, it can be concluded that winter is the best season for breeding and conservation of domestic rabbits.

Parasitological, pathological and functional studies on the effects of IFN alpha 2b in murine hepatic schistosomiasis.

The effects of different doses of Interferon alpha 2b (IFN alpha 2b), alone and in combination with praziquantel (PZQ), on hepatic schistosomiasis were tested. An experimental murine model of hepatic schistosomiasis was used. Four parameters were assessed; hepatic fibrosis by estimation of OH-proline content/g dry weight liver, hepatocyte proliferative activity by the PCNA/LI, schistosomal egg load by digesting parts of the liver by KOH and hepatocyte function by measuring parenchymal liver enzyme levels. IFN alpha 2b was found to increase hepatic fibrosis in a dose dependent manner both alone and in combination with PZQ. An augmentation of the regenerative activity of the liver was observed. A reduction in the number of the granulomas and egg counts was observed only when PZQ was added. However, no effect on the size of the granulomas was observed apart from the normal process of modulation. Caution should be exercised when treating patients with concomitant hepatic schistosomiasis and hepatitis with IFN alpha 2b as it increases both hepatocyte regenerative activity and hepatic fibrosis; two main components of cirrhosis.

Autoclaved cercarial vaccine against schistosomiasis: ultrastructural and biochemical studies.

Autoclaved cercarial vaccine (ACV) was found to be highly effective in eliciting protective immunity against experimental Schistosomal mansoni. So, the aim of this study was to analyse ACV biochemically and to study ultrastructural changes inflicted on the cercariae as a result of autoclaving, thus rendering it highly protective. Results of this study showed that approximately 100 microg protein and 44 microg carbohydrate were obtained from 10(3) cercariae. The predominant sugar was fucose. Galactose, glucose, manose, galactosamine and glucosamine were also detected. Threonine, glycine, serine and glutamic acid comprised approximately 53.7% of the amino acid residues of the protein. Ultrastructural study revealed preserved architecture of the cercariae. The tails were still attached to the posterior ends of the bodies. However, in others the tails were separated from the bodies and appear schistosomula like. There were also some morphological changes such as thinning of the pericortical envelop with appearance of surface pores.

Gall bladder sludge and stones in multitransfused Egyptian thalassaemic patients

One hundred Egyptian beta-thalassaemic patients on a long-term transfusion/chelation programme were evaluated for the prevalence of all bladder sludge and stones and the associated risk factors. Fifty healthy individuals served as controls. Abdominal ultrasonography revealed that 14% of the thalassaemic patients had gall bladder sludge or stones [6% stones and 8% sludge]. The thalassaemic patients with this complication were older, had a higher prevalence of gall bladder symptoms, higher levels of pretransfusion haemoglobin, larger amounts of transfused red cells, and more were regularly transfused. Multiple logistic regression analysis revealed that the presence that gall bladder symptoms and the amount of transfused red cells were the only significant predictors of the occurrence of gall bladder sludge or stones

diagnostic value of fine needle aspiration cytology in thyroid swellings in a University Hospital, Yemen

To evaluate the correlation between the fine needle aspiration [FNA] cytology and the histopathological findings in cases of the thyroid swellings and to assess the accuracy of cytological examination of thyroid nodules. This study was carried out at Kuwait University Hospital, Sana'a, Yemen. There were 243 thyroid FNAs of which 199 had subsequent excisional histopathological examination in the period 1997 to 2001. All the records of cytology and histology were reviewed. Cases were classified into 6 subsets: benign follicular lesion, thyroiditis, follicular neoplasm, suspicious for papillary carcinoma, malignant, and non-diagnostic aspirate. For statistical analysis, we excluded cases, which had not had subsequent histopathological examination [n=44], and cases with non-diagnostic aspirate [n=3], so only the histology and medical records of 196 cases were reviewed and correlated with the cytology results. There were 156 [78.4%] cases of benign aspirate, 31 [15.6%] cases of follicular neoplasm, 4 [2%] cases that were suspicious for papillary carcinoma, 4 [2%] cases of papillary carcinoma, and 3 [1.5%] cases of non-diagnostic aspirates. The 196 cases, which underwent cytological and histopathological examinations, were classified as non-neoplastic and neoplastic [including follicular neoplasm and malignancy] according to postoperative histopathology and correlation which, was carried out with preoperative cytology. There were 115 true negatives, 26 true positives, 42 false negatives, and 13 false positives. This gives a sensitivity of 38%, specificity of 89.9%, positive predictive value of 66.7%, negative predictive value of 73.2%, and accuracy of 72%. The sensitivity of FNA cytology in this study is very low compared to published studies, which had adversely affected the surgical decision making as well as the outcome. We should realise that negative FNA cytology does not exclude malignancy and we have to seriously evaluate the situation and to rethink on how to raise the scale of sensitivity in FNA cytology in the diagnosis of thyroid nodules, and to improve the level of expertise in cytology