Abstract

Hyperglycaemia, a key metabolic abnormality in diabetes mellitus, is implicated in pathological cardiogenesis during embryological development. However, the underlying mechanisms and potential therapeutic targets remain unknown. We, therefore, studied the effect of hyperglycaemia on mouse embryonic stem cell (mESC) cardiac differentiation. The mESCs were differentiated via embryoid body (EB) formation and cultured under conditions with baseline (25 mM) or high (50 mM) glucose. Time-lapse microscopy images of pulsatile mESCs and Ca2+ntransients were recorded. Biomarkers of cellular changes were detected using immunocytochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay, and Western blot analyses. Differentiated, spontaneously beating mESCs stained positive for cardiac troponin T, α-actinin 2,nmyosin heavy chain, and connexin 43. Hyperglycaemia decreased the EB diameter and number of beating EBs as well asnthe cellular amplitude of contraction, the Ca2+ transient, and the contractile response to caffeine (1 mM), but had no effect. on the expression of the sarco-endoplasmic reticulum calcium transport ATPase 2 (SERCA 2). Furthermore, hyperglycaemia decreased the expression of B cell lymphoma 2 (Bcl-2) and increased the expression of cytoplasmic cytochrome c and the number of TUNEL-positive cells, but had no effect on the expression of one of the mitochondrial fusion regulatory proteins, optic atrophy protein 1 (OPA1). Overall, hyperglycaemia suppressed the mESC cardiomyocyte-like differentiation and induced contractile dysfunction. The results are consistent with mechanisms involving abnormal Ca2+ handling and mitochondrial-dependent apoptosis, factors which represent potential therapeutic targets in developmental diabetic cardiac disease.

Small molecule, (2-(2-(2-nitrophenyl)diazenyl)malononitrile) (NPDAM), is synthesized and its chemical structure is characterized by different analyses. NPDAM powder is identified as polycrystalline monoclinic structure, whereas the thermally deposited films have nanostructure character with average particle size of 39 nm. NPDAM films are utilized for manufacturing hybrid solar cells in the structure of Au/NPDAM/p-Si/Al. The dark current-voltage (I-V) curves of the diode are measured in the temperature range 303-383 K and the thermionic emission theory is employed to extract the ideality factor, n, and potential barrier height, ∅ at forward applied voltages of V≤0.20 volt. The n value increases, whereas the ∅ value decreases with decreasing temperature. This behavior is analyzed in terms of the lateral inhomogeneous barrier following Gaussian distribution at the NPDAM/p-Si interface. Cheung and Cheung functions are used for extracting the values of series resistance, Rs, n and ∅. The behavior of these parameters as a function of temperature is discussed. At forward applied voltages 0.20<V≤2, the I-V relation reveals crossover from thermionic emission to square power law. This behavior is discussed by means of the space charge limited current. Under illumination, the device exhibits a response to light exposure with a photoelectrical conversion efficiency of 2.91 %.

The groundwater aquifers in Azintan, northwestern Libya suffer from an acute shortage of water. The groundwater was evaluated to determine its suitability for drinking and irrigation purposes from major two aquifers in north and south of Azintan area. This study carried out to assess the groundwater quality and to identify major affecting variables. Twelve samples from the two aquifers were collected. The two aquifers were collected and analyzed for total dissolved solid (TDS), electrical conductivity (EC), pH, Ca2+, Mg2+, Na+, K+, Cl-, SO42-, CO32- and HCO3-. The results show that, the groundwater in many places is dominated by higher concentrations of Cl-, SO42- and HCO3-. Two water types were recognized in this region are Cl-SO4-Na-Ca and Cl-SO4-Na. Gibbs and Piper method, as well as the hardness, soluble sodium percentage and the permeability index all have been used to assess the diagram quality of the groundwater of aquifers. Further, the multiple correlations and Cluster Analysis of groundwater quality parameters were carried out for further classification and interpretation of the groundwater quality. Finally, water qualities in the study area are compared with Libyan standards and WHO guidelines of drinking water and irrigation purposes.

The term of earnings management is sometimes used in literature as a synonym for accounting reporting fraud. Thereby, this paper aims to review the existing literature to offer a better clarification to the primary characteristics and differentiation between earnings management and accounting reporting fraud. The results of other previous studies have been reviewed to demonstrate the results of this study using a number of alternatives available resources to the collection of the relevant literature. The findings demonstrate that the activities of manipulating financial information continue to prevail in the business environment worldwide, despite the fact that there are strict laws and regulations to prevent earnings management and fraud behaviour. Therefore, defining the motivation of managers manipulative behaviour can enable academics and regulators to establish a framework to distance between earnings management and fraud and to recognize fraudulent actions through attempting to pursue how managers act to achieve their objectives.

Group work is believed to be one of the possible solutions to the problem of dealing with large number of students within one speaking class. However, how students perceive group work in their EFL speaking classes is an area that needs to be researched. This study looks at how students perceive group work in their speaking classes and their preference of being given a specific role in a given speaking task that involves working in a group. A questionnaire has been distributed to 42 students to highlight their perceptions towards group work. Results from this study revealed that EFL students seem to like the idea of working in groups in their speaking classes as they reported a number of benefits that they gain when they work in groups, for example, they feel more independent, they have a chance to share ideas, and they speak English in most of the time in the class. However, a number of drawbacks have been also reported by the students, for example, the domination of one student in the group, some students find it difficult to work in a group of mixed gender, and low level students sometimes feel frustrated to work in group.