A total of 240 1-day-old broiler chicks (Cobb500) were purchased from a local hatchery and randomly distributed into four dietary treatments. Each treatment comprised 5 replicates with 12 chicks each. Garlic powder (Allium sativum) was supplemented as follows: 0.0%, 0.1%, 0.2%, and 0.3%. The diets were formulated to be approximately isocaloric and cover all nutrient requirements for broilers throughout two stages of growth periods: starter diets (1–21 days) and finisher diets (22–42 days). At the end of the experiment, one bird was chosen from each replicate to measure the carcass characteristics and blood was collected.

Background: Medical students have been shown through multiple studies to be more susceptible to stress and depression than the rest of the population. Libyan students specifically have to undergo the challenges of becoming a doctor while living in the terrifying and stressful outcomes of the Libyan civil war. And the spread of COVID-19 has added to these stressors.

Objective: This study aimed to determine prevalence of depression and anxiety among Libyan medical students and analyze the causing factors.

Methods: A cross sectional study was conducted using an online survey. The survey used the K-10 Kessler psychological distress scale which is a self administered questionnaire used to measure the level of distress. 

Results: A total of 1348 students from 16 Libyan medical schools across the 5 years of study completed the survey. 992 (73.6%) were female students and 356 (26.4%) were male. The mean age (SD) was 22.09 (2.56).

Out of the 1348 participants, 638 (47.3%) scored for severe mental disorder. 213 (15.8%) scored for moderate mental disorder and 200 (14.8%) presented with mild mental disorder. 297 (22%) of the students are likely to be well according to the K-10 psychological distress scale. Out of the students who have had their houses displaced due to the war, 66.3% have presented with moderate to severe mental disorder.

 235 students (17.4%) have reported having suicidal thoughts throughout their time in medical school.

Conclusion: In comparison to similar studies done in other countries, Libyan students scored a higher prevalence of depression. The stress of the current political state of the country and the COVID-19 pandemic were shown to be contributing factors.

Abstract

Diabetes mellitus with hyperglycaemia is a major risk factor for malignant cardiac dysrhythmias. However, the underlying mechanisms remain unclear, especially during the embryonic developmental phase of the heart. This study investigated the effect of hyperglycaemia on the pulsatile activity of stem cell-derived cardiomyocytes. Mouse embryonic stem cells (mESCs) were differentiated into cardiac-like cells through embryoid body (EB) formation, in either baseline glucose or high glucose conditions. Action potentials (APs) were recorded using a voltage-sensitive fluorescent dye and gap junction activity was evaluated using scrape-loading lucifer yellow dye transfer assay. Molecular components were detected using immunocytochemistry and immunoblot analyses. High glucose decreased the spontaneous beating rate of EBs and shortened the duration of onset of quinidine-induced asystole. Furthermore, it altered AP amplitude, but not AP duration, and had no impact on neither the expression of the hyperpolarisation-activated cyclic nucleotide-gated isoform 4 (HCN4) channel nor on the EB beating rate response to ivabradine nor isoprenaline. High glucose also decreased both the intercellular spread of lucifer yellow within an EB and the expression of the cardiac gap junction protein connexin 43 as well as upregulated the expression of transforming growth factor beta 1 (TGF-β1) and phosphorylated Smad3. High glucose suppressed the autorhythmicity and gap junction conduction of mESC-derived cardiomyocytes, via mechanisms probably involving TGF-β1/ Smad3 signalling. The results allude to glucotoxicity related proarrhythmic effects, with potential clinical implications in foetal diabetic cardiac disease.

Ab s t rac t

Aim: The aim of this study was to evaluate the efficacy of grape seed extract (GSE) on remineralization of surface and subsurface enamel lesions 

compared to that of sodium fluoride (NaF).

Materials and methods: A total of 20 intact bovine incisor crowns were separated from their roots and immersed in a demineralizing solution 

for 96 hours at 37°C to create artificial enamel lesions. The specimens were randomly divided into two groups (n = 10): 6.5% GSE solution 

and 1000 ppm NaF solution. The specimens were subjected to six daily pH cycles for 8 days. The microhardness test was carried out at three 

different stages: baseline, after artificial caries formation, and after pH cycling. Raman spectroscopy was used to evaluate the depth of enamel 

remineralization. Surface morphology and elemental analysis were assessed using a scanning electron microscope (SEM) and an energy dispersive 

X-ray (EDX) spectroscope, respectively. Statistical analysis was performed using SPSS 22.0 at a significance level of p ≤ 0.05.

Results: There was a significant increase in the mean values of enamel surface microhardness after pH cycles in the two groups compared to 

after artificial caries formation, but there was no significant difference between both groups. The B-type carbonate/phosphate (Ca/P) ratio at 

10 and 40 µm depth revealed no significant difference between the two groups. Scanning electron microscope micrograph revealed occlusion 

of porosities and particle precipitation on the enamel surface of the two groups, while EDX results for the Ca/P ratio of the GSE and NaF groups 

were 1.59 and 1.60, respectively.

Conclusion: Grape seed extract and NaF are equally effective in remineralizing surface and subsurface artificial enamel lesions.

Clinical significance: Grape seed extract can be considered a promising herbal material and a safe alternative to traditional NaF for the 

noninvasive treatment of enamel lesions.

Keywords: Enamel remineralization, Grape seed extract, Microhardness, pH cycling model, Raman spectroscopy, Sodium fluoride.