A Study of the Turbulent Flows in Sloping and Adversely Sloping Rectangular Culverts

In this paper, an experimental investigation was carried out to study the turbulent flows and flow characteristics through sloping and adversely sloping rectangular culverts in a rectangular channel of constant width using Laser Doppler Velocimetry (LDV). Also, experimental study was carried out to investigate the characteristics of the hydraulic jump occurring in a sloping and adversely sloping rectangular culvert with pressurized flow downstream from the jump and a submerged culvert outlet. Experiments were conducted on a culvert with relatively small slopes to study the variation of the relative tailwater depth with the main parameters affecting the jump in sloping and adversely sloping culverts. These parameters include the channel bottom slope, the initial Froude number and the ratio of the initial depth to culvert height. To study the turbulence characteristics, precise and accurate measurements of the mean fluctuating flow quantities such as streamwise and vertical mean velocity components, and streamwise and vertical turbulence intensity components and turbulence shear stress were carried out. Also, this paper presents the results of a Laser Doppler Velocimetry study of hydraulic jumps in a culvert with different relative tailwater depths and different initial Froude numbers. The characteristics of hydraulic jumps were discussed and analyzed. Non– dimensional design curves were provided to relate the jump characteristics. The maximum vertical velocity in the recirculating zone for all jumps is about 6% of the initial velocity. The results show that the maximum streamwise velocity near the center plane was smaller than that near the side wall. The turbulence shear stress near the center was about (35-45)% higher than that near the side wall. After the jump, the flow will recover into a two-dimensional flow

Creating movable interfaces by micro-powder injection moulding

This paper presents a novel in situ technique to produce articulated components with high-precision, micro-scale movable interfaces by micro-powder injection moulding (μPIM). The presented process route is based on the use of micro-scale sacrificial layer between the movable subcomponents which is eliminated during the debinding step, creating a dimensionally-controlled, micro-scale mobile interface. The fabrication technique combines the advantages of micro-powder overmoulding, catalytic debinding and sintering. The demonstrated example was a finger bone prosthesis joint consisting of two sub-components with an interface between components of 200 μm in size. The geometries of the sub-components were designed such that they are inseparable throughout the process whilst allowing them to move relative to each other after the debinding stage. The components produced showed the feasibility of the process route to produce readily-assembled meso-, and potentially micro-, scale articulated system

Risks of Environmental Genotoxicants

Humans have throughout their development been exposed to various environmental genotoxicants through food, air, water, and soil. Environmental exposure to genotoxic compounds may induce damage to human health and thereby increase risks of human cancers and other diseases. Environmental genotoxic chemicals have the ability to induce mutations. Such mutations can give rise to cancer in somatic cells. However, when germ cells are affected, the damage can also have an effect on the next and successive generations. Because of the potential health hazard represented by exposure to genotoxic chemicals, it is important that all chemicals for which there is possible human exposure be screened for genotoxic activity. If genotoxic hazard is detected, then the risks of exposure can be assessed and the use of the chemical controlled and when appropriate eliminated from the market and the environment. In this chapter, a general overview of the genotoxicity and the genotoxicity of some environmental genotoxicants are discussed. This is followed by a description of the genotoxic properties of some environmental genotoxicants such as bisphenols and mycotoxins, which are prominent environmental contaminates, and is believed to be genotoxic agents that contribute to the high incidence of carcinogenicity among populations

Water status and yield response to deficit irrigation and fertilization of three olive oil cultivars under the semi-arid conditions of Tunisia

Sustainability of olive production is possible by adopting the modern techniques of irrigation and fertilization. In Tunisia, olive trees are usually cultivated in poor soils, under semi-arid conditions characterized by water scarcity. This study investigated the effects of different water supply and fertilization on leaf water status and crop yield of three different olive oil varieties cultivated in central Tunisia, during four experimental seasons (2014-2017). Three treatments were examined: trees conducted under rainfed conditions (TRF), which represented the control treatment, trees irrigated with 50% ETc (T50) and, finally, trees irrigated with 50% ETc and with additional fertilization (T50F). Leaf water content and potential, yield and water use efficiency have been monitored on three different varieties, Chetoui, Chemlali, and Koroneiki, which are quite typical in the considered region. For all the growing seasons, midday leaf water potentials were measured from April to September. Midday leaf water potentials (MLWP) were generally higher for the two irrigated treatments (T50 and T50F) than for non-irrigated trees (TRF). As the season proceeded, MLWPs tended to decrease during summer for all the treatments and varieties. The lowest values were observed for the non-irrigated trees, varying between -3.25 MPa to -4.75 MPa. Relative leaf water content followed the same trends of midday leaf water potentials. Chetoui showed the lowest yield, which did not exceed 1530 Kg/(ha year), even for irrigated and fertilized trees. On the other hand, the yields of Chemlali and Koroneiki, cumulated in the four years, reached the maximum value of about 20 tons/ha. For these two varieties, the cumulated yield obtained in the control treatment (TRF) resulted significantly lower than the corresponding of the other two treatments (T50 and T50F). The highest irrigation water use efficiency (WUE) was estimated for Chemlali (T50) and (TRF). WUE was equal to 1.22 Kg/m3 for Koroneiki under fertigated treatment (T50F). Application of the only water supply (50% ETc) or associated with fertilizer improved the tree water status and increased the productivity of Chemlali and Koroneiki varieties

Natural Cholesterol Busters

Hypercholesterolemia, a risk factor for cardiovascular and cerebrovascular diseases, is a silent health problem. It occurs due to buildup of large amount of cholesterol in blood vessels resulting in narrowed blood vessels or blockage of the flow of blood and causes cellular dysfunction. The predisposing factors for hypercholesterolemia are carbohydrates‐enriched diet, unhealthy fats, and red meat. Moreover, family history, obesity, hypokinetic lifestyle, aging, and oxidative stress are associated with hypercholesterolemia. Therapeutic interventions of hypercholesterolemia involve cessation of bad habits, regular exercise, consumption of cholesterol buster diets, and cholesterol‐lowering drugs. However, cholesterol‐lowering drugs have low efficacy, and some patients cannot tolerate the adverse effects of hypocholesterolemic drugs. In light of this, there has been great interest to address natural cholesterol busters as first choice as cholesterol‐lowering option. Healthy diet, regular exercise and natural cholesterol‐lowering agents are documented to decrease blood cholesterol level. Natural cholesterol busters include dietary fibers, plant sterols, healthy fats, smart proteins, antinutrients, antioxidants, and L‐arginine. These busters not only decrease cholesterol oxidation and absorption but also increase cholesterol catabolism and elimination. Most of these busters are found in cereals, oatmeal, fruits, vegetables, legumes, and fermented foods. The natural cholesterol busters are recommended strategies for treatment of hypercholesterolemia alone or in combination with cholesterol‐lowering drugs

Perceived health and quality of life: the effect of exposure to atmospheric pollution

International audienc

Phenotypic and Genotypic Identification of Vancomycin Resistant Enterococci from Different Sources

Enterococci are reservoirs for transmission of the most clinically important antimicrobial resistances such as vancomycin resistance. Therefore, this work aimed to determine the occurrence of enterococci and their respective vancomycine resistance genes (vanA and vanB) from different sources. Two hundred and twenty-four samples from chickens, turkey, fish and human urine, as well as, two types of human food including milk (raw and milk from mastitic animals) and sausage were tested for isolation of Enterococcus species. The isolates were identified morphologically and biochemically using catalase test, sodium chloride tolerance and growth at pH 9.6 and 10- 45˚C. The vancomycin resistance profile of the isolates was verified by both disc diffusion and agar dilution methods. The genotypic enterococcal identification at both genus and species levels and their vancomycine resistance genes were also ascertained using PCR amplification of the respective genes for 28 isolates. Enterococci isolation rate was 70% of the examined samples with a higher percentage of vancomycine resistance (53.5%) and the minimum inhibitory concentrations (MICs) ranged from 16 to 512 µg/mL. Molecular identification of 28 enterococcal isolates revealed the dominance of E. faecalis (42.8%) and clarified a higher proportion of vanA (78.5%) and vanB (67.8%) genes. In conclusion, administration of the antimicrobials mainly vancomycin may be considered as a pronounced stress factor in the veterinary and human practices. In addition, VRE can act as a reservoir for vancomycin resistance

Influence of pravastatin chitosan nanoparticles on erythrocytes cholesterol and redox homeostasis: An in vitro study

AbstractThe objective of this study was to develop and characterize chitosan nanoparticles (CSNPs) to increase efficacy of pravastatin (PR) on erythrocytes redox status. CSNPs and PR loaded CSNPs (PRCSNPs) were prepared by ionic gelation method. The particle size, zeta potential, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) were used to investigate physicochemical characters of the prepared nanoparticles. The present results revealed that CSNPs and PRCSNPs have nanosize about 90nm with spherical shape, positive zeta potential and prolonged PR release. Moreover, DSC and FTIR indicated no chemical interactions between PR and CS. In vitro studies revealed that, erythrocyte uptake of PR from PRCSNPs was higher than free PR solution. Incubation of erythrocytes in high cholesterol plasma, hypercholesterolemia (HC), increases membrane cholesterol, erythrocyte hemolysis, oxidized glutathione (GSH), protein carbonyl (PCC), and malondialdeyhe (MDA). However, HC significantly decreases PR uptake by erythrocytes, superoxide dismutase (SOD), glutathione peroxidase (GPx) catalase (CAT) activities, reduced GSH and nitrite levels compared to control. By contrast, treatment of HC with PR plus CS as free drug or nanostructure formula keeps the measured parameters at values near that of control. The effect of CSNPs and PRCSNPs on redox status of erythrocytes was more prominent than free drugs. In conclusion, PRCSNPs are promising drug carrier to deliver PR into erythrocytes, moreover, PRCSNPs possess promising characteristics with high biological safety for treatment of HC induced disruption of redox homeostasis

BCR-ABL Tyrosine Kinase Inhibitors as Candidates for the Treatment of COVID-19: Molecular Docking, Pharmacophore Modeling, ADMET Studies

The novel coronavirus pandemic (COVID-19) caused by SARS-CoV-2 has affected more than 53 million individuals worldwide. Currently, there is a dire need to develop or find potential drugs that can treat SARS-CoV-2 infection. One of the standard methods to accelerate drug discovery and development in pandemics is to screen currently available medications against the critical therapeutic targets to find potential therapeutic agents. The literature has pointed out to the 3CLpro and RdRp proteins as the most important proteins involved in viral replications. In the present study, we used an in-silico modeling approach to examine the affinity of six tyrosine kinases inhibitors (TKIs), Imatinib, Ponatinib, Nilotinib, Gefitinib, Erlotinib, and Dasatinibagainst the 3CLpro and RdRp by calculating the energy balance. The six tested TKIs had energy balance values of more than -7 Kcal/mol for both viral target proteins. Nilotinib and Ponatinib showed the highest affinity for 3CLpro (-8.32, -8.16, respectively) while Dasatinib, Ponatinib, and Imatinib presented the strongest binding toRdRp(-14.50, -10.57, -9.46, respectively). Based on these findings, we recommend future evaluations of TKIs for SARs-CoV-2 infection in-vitro and further testing in clinical trials

Composición bioquímica y potencial antioxidante del pepino del mar Mediterráneo comestible Holothuria tubulosa

The sea cucumber or holothurian is a marine species which has been prized in some Asian coun­tries for its nutritional qualities. The purpose of this work was to study the biochemical composition and free radical scavenging and antioxidant activities of Holothuria tubulosa tegument from the Bizerta lagoon in north­ern Tunisia. The obtained data demonstrated that the extract of sea cucumber teguments exhibited high bio­chemical levels (such as moisture 80.77%, protein 7.07%, lipids 10.21%, energy value 13.64 Kcal/g ww), and an important nutritional value (including n-3/n-6: 2.11, EPA+DHA: 20.96, AI: 1.38 and TI: 0.54). High anti­oxidant activities were recorded in the integument by the radical scavenging tests of ABTS and DPPH as well as by the total antioxidant capacity and the FRAP in comparison with the BHT standard. Our results showed that H. Tubulosa tegument has high nutritional value with high antioxidant activities and could be considered a nutraceutical product.El pepino de mar o la holoturia es una especie marina apreciada en algunos países asiáti­cos por sus cualidades nutricionales. El propósito de este trabajo fue estudiar la composición bioquímica y las actividades antioxidantes y de eliminación de radicales libres del tegumento de Holothuria tubulosa de la laguna de Bizerta, en el norte de Túnez. Los datos obtenidos demuestran que el extracto de tegumentos de pepino de mar mostró altos niveles bioquímicos (como humedad 80,77%, proteína 7,07%, lípidos 10,21%, valor energético 13,64 Kcal/gww) y un valor nutricional importante (incluyendo n-3/ n-6: 2,11, EPA+DHA: 20,96, AI: 1,38 y TI: 0,54). Se registraron altas actividades antioxidantes en el tegumento mediante las pruebas de eliminación de radicales de ABTS y DPPH, así como por la capacidad antioxidante total y el FRAP, y esto, en comparación con el estándar BHT. Nuestros resultados mostraron que el tegumento de H. Tubulosa tiene un valor nutricional importante con una alta actividad antioxidante y podría considerarse un producto nutracéutico