Morning exercise improves sleep quality in university students

Background: Although sleep is influenced by exercise, a proper management of physical activity’s time promotes the quality of sleep. The objective of this study was to evaluate, in university students, the effect of morning or evening physical exercise on sleep pattern, along with the dynamics of hormones controlling sleep quality.Methods: We recruited 92 healthy sedentary adolescents, 18-20 year-old, poor sleepers, with normal anthropometric characteristics and no musculoskeletal or neurological problems. They were randomly distributed into 3 groups:  34 subjects practicing morning physical activity, 28 subjects practicing evening physical activity, and 30 subjects remained sedentary. The quality of their sleep was assessed using the Spiegel validated questionnaire. Body temperature was recorded in the morning and evening, and saliva samples were collected. Saliva cortisol and melatonin levels were evaluated by ELISA.Results: The group practicing exercise in the morning experienced a better quality of sleep (71.4%) versus the one exercising in the evening (44.1%, p<0.05). In parallel, the levels of melatonin and cortisol significantly increased, at night and morning simultaneously, in participants exercising in the morning. Moreover, body temperature significantly decreased in participants that exercised in the morning compared to those who practiced evening exercise, or maintained a sedentary lifestyle (p<0.05).Conclusions: Our data indicate that morning physical activity exerts a positive impact on the sleep quality, probably by decreasing cortisol and increasing melatonin levels in the evening. We presume that morning activity may efficiently reduce the burden of sleep disorders, particularly those caused by COVID-19 lockdown

Structure of a Plane Shock Layer

The structure of a plane shock wave is discussed and the expected range of applicability of the Navier‐Stokes equations within the shock layer is outlined. The shock profiles are computed using the Bhatnagar‐Gross‐Krook model of the Boltzmann equation and a uniformly converging iteration scheme starting from the Navier‐Stokes solution. It is shown that the Navier‐Stokes solution remains a good approximation in the high‐pressure region of the shock layer up to approximately the point of maximum stress for all shock strengths. In the low‐pressure region, the correct profiles deviate with increasing shock strength from the Navier‐Stokes solution. The physical significance of the kinetic model used and the relation of the present study to previous theoretical and experimental work is discussed

Theoretical and Experimental Aspects of the Shock Structure Problem

Flow of rarefied gases - Shock wave structure proble

Effects of dishwashing detergents residues on redox status and cell proliferation in mice liver and kidney

Background: Commonly known for their cleaning and disinfecting properties, dishwashing detergents containing anionic surfactants can be potentially toxic due to misuse. This study aims to investigate the possible harmful effects of detergents residues persisting on utensils after dishwashing.Methods: Residues were collected after cleaning the utensils in 100 mL of water from 100 households in Beirut, Lebanon. After anionic surfactant determination, water with detergent residues (WDR) was added to drinking water of white mice versus tap water as control: G1 (TW for 2 months), G2 (WDR for 2 months), G3 (TW for 3 months) and G4 (WDR for 3 months), N=6 for each group. Animals were then sacrificed. Biopsies from liver and kidneys were taken for histological examination or preserved at -80°C for biochemical analysis of lipid peroxidation, superoxide dismutase activity, and expression of PI3K/AKT/mTOR pathway proteins by western blotting.Results: Our results showed no significant difference in body weight or histological alteration in groups given WDR versus TW groups. An increase of LP (30%) and a decrease of SOD activity (25%) were noted in the liver tissue of G2 and G4 versus G1 and G3 respectively (p<0.05). In addition, p-AKT and p-mTOR proteins expression regulating cell proliferation were significantly increased in the liver of G4 versus G3 (p<0.05).Conclusions: We concluded that traces of detergents on utensils do not cause an acute pathology, but they could cause oxidative stress to the liver and an over-expression of cancer pathway over a relative long period of time

Optimal Design of a Golf Club using Functionally Graded Porosity

The current work portrays a new concept of designing and manufacturing golf club heads with functionally graded porosity (FGP) by means of electron beam melting® (EBM®). In light of the advancement of additive manufacturing (AM) technologies and the consequent wide spread applications in the aerospace, automotive, and biomedical industries, the current work discusses a new application in sport technologies; for example, in the golf industry. EBM® makes it possible to print the designed porosity within a golf club head, to reduce the weight and optimize performance. The focus is to design the golf club head with FGP to improve performance and reduce weight. The dynamic properties of porous materials are investigated theoretically. The porosity in the club head was analyzed numerically by simulating the impact between the club head and a steel ball in order to determine the coefficient of restitution (COR) of the club head. The simulation’s parameters are in compliance with the U.S Golf Association’s (USGA) test procedure for measuring COR.Mechanical Engineerin

Determination of antioxidant activity of saffron taken from the flower of Crocus sativus grown in Lebanon

Since oxidative stress has been implicated in most common cause of death, especially in case of cancer and cardiovascular disease, natural substances and spices that show antioxidant effects merit a closer examination. Saffron is the yellow natural spice derived from the flower of Crocus sativus and used as a coloring agent in many foods worldwide. In this study, we determined the total polyphenols content in the Lebanese saffron and the antioxidant effects of different extracts from this saffron in vitro using electrolysis of physiological solution for generation of free radicals (FR) in the presence of colorimetric indicator N,N-di-ethyl-P-phenylenedialanine; the absorbance was measured spectrophotometrically at 515 nm. Histophathological studies allowed us to observe the damages caused by FR in the isolated organs of hamsters (kidney, liver, lungs, and heart) and on the other hand the protection that saffron provided to these vital organs. By using assay kits, we evaluated the levels of lipid peroxidation and superoxide dismutase activity, the important free radical scavenging enzyme. The results showed that both boiled and soaked saffron at 0.45 mg/ml are highly effective against FR generated by electrolysis and against the damages caused to the organs tested as observed by light microscopy. Moreover, saffron significantly (p &lt; 0.05) decreased lipid peroxidation and increased superoxide dismutase activity in all tissues used as compared to control. We concluded that Lebanese saffron strongly protects vital organs against oxidative stress.Key words: Crocus sativus, oxidative stress, free radicals, Lebanese saffron, antioxidant activity, free radicals scavengers

The critical Ising lines of the d=2 Ashkin-Teller model

The universal critical point ratio $Q$ is exploited to determine positions of the critical Ising transition lines on the phase diagram of the Ashkin-Teller (AT) model on the square lattice. A leading-order expansion of the ratio $Q$ in the presence of a non-vanishing thermal field is found from finite-size scaling and the corresponding expression is fitted to the accurate perturbative transfer-matrix data calculations for the $L\times L$ square clusters with $L\leq 9$.Comment: RevTex, 4 pages, two figure

Capture and inception of bubbles near line vortices

Motivated by the need to predict vortex cavitation inception, a study has been conducted to investigate bubble capture by a concentrated line vortex of core size rcrc and circulation Γ0Γ0 under noncavitating and cavitating conditions. Direct numerical simulations that solve simultaneously for the two phase flow field, as well as a simpler one-way coupled point-particle-tracking model (PTM) were used to investigate the capture process. The capture times were compared to experimental observations. It was found that the point-particle-tracking model can successfully predict the capture of noncavitating small nuclei by a line vortex released far from the vortex axis. The nucleus grows very slowly during capture until the late stages of the process, where bubble/vortex interaction and bubble deformation become important. Consequently, PTM can be used to study the capture of cavitating nuclei by dividing the process into the noncavitating capture of the nucleus, and then the growth of the nucleus in the low-pressure core region. Bubble growth and deformation act to speed up the capture process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87832/2/022105_1.pd

Evaluation of renal drug dosing adjustment in chronic kidney disease patients at two university hospitals in Lebanon

Background: Inappropriate medication dosing in patients with chronic kidney disease can cause toxicity or ineffective therapy. Patients are at a high risk of developing related adverse events caused by the altered effect of drugs in conjunction with the use of polypharmacy to treat comorbid conditions. This necessitates adequate renal dosing adjustments. Objective: The current study aims at assessing whether appropriate dosing adjustments were made in hospitalized patients with chronic kidney disease. Methods: A retrospective descriptive study was conducted at two university hospitals in Beirut between January and December 2016. All adult CKD patients with creatinine clearance less than 60 ml/min and receiving at least one medication that require renal dosing adjustment were included. Kidney function was estimated from serum creatinine using Cockcroft-Gault equation, and dose appropriateness was determined by comparing practice with specific guidelines. The rates of renal drug dosing adjustment were investigated, in addition to the influence of possible determinants, such as the severity of renal impairment, reason of hospital admission, and other patient characteristics. Results: 2138 patients admitted in 2016 were screened. 223 adults receiving 578 drug orders that require adjustment were included. Among the 578 orders, 215 (37%) were adjusted adequately, 284 (49%) were adjusted inadequately, and 79 (14%) were not adjusted at all. Beta-blockers were the most inadequately dosed (83.6%) class of medication, whereas lipid-lowering agents had the highest percentage of adequate dosing (65.1%). As per patient, 84.3% of patients appeared to be receiving at least one inappropriate drug dose. Conclusions: Our study confirms that physicians are not prescribing appropriate dosing adjustments in chronic kidney disease inpatients, which may have deleterious effects. This highlights the need for more nephrology consultation and the implementation of physician education programs