Effect of Chronic hypoxia on Carotid vascular responses to noradrenaline in rats

Aim: The aim of the present study was to examine whether chronic hypoxia would alter the noradrenaline (NA)-evoked vascular responses in carotid circulation in rats. Furthermore, whether the carotid autoregulatory response to NA-evoked rise in arterial blood pressure (ABP) is compromised by chronic hypoxia or not. Also, the role of tonically synthesised nitric oxide (NO) in these responses was investigated.Methods: the study was done using two comparable age groups of adult Wistar rats; the first were breathing normal 21% O2 (normoxic; N), whereas the second were made chronically hypoxic (CH) by breathing 12% O2 for 3 weeks, while they were growing from 7 to 10 weeks. In anaesthetised rats, the carotid blood flow (CBF) and carotid vascular conductance (CVC) were recorded during a 3 min infusion of NA at a dose 2.5 μg kg-1 to induce an acute rise in ABP to 150 mm Hg, the upper limit of autoregulatory range, before and after a bolus dose of the nitric oxide synthase inhibitor, L-NAME (10mg kg-1).Results: the NA-evoked rise in ABP was comparable in N and CH rats, but the increase in heart rate was more significant in CH rats. In CH rats, the NA-evoked rise in ABP was associated with a significant reduction in CVC but with no change in CBF, whereas in N rats the reduction in CVC was accompanied with a significant reduction in CBF (p<0.05). In both groups, L-NAME did not accentuate the rise in ABP induced by NA. However, in CH rats the reduction in CBF became more significant after L-NAME.Conclusion: the carotid vasculature in CH rats is less sensitive to vasopressor effect of NA, when compared to N rats. However, the carotid autoregulatory response to NA-induced rise in ABP was not compromised by chronic hypoxia. Further, it seems that NO does not play a role in the blunted carotid vasoconstrictor responses to NA in CH rats.Keywords: Chronic hypoxia, carotid circulation, noradrenalin, nitric oxid

Design of a seed extractor using the physical and mechanical properties of cucumber fruits

AbstractThe aim of this investigation is to study some physical and mechanical properties of cucumber fruits to help the design of handling machines for seed production. The physical and mechanical properties of cucumber fruits are used to develop of a seed-extractor.The main results in this study can be summarized as follows:Physical properties of cucumber fruits: fruit diameter = 50 -  68, 60 - 76 and 56  - 75 mm, fruit length = 169 – 291, 230 – 315 and 180 – 295 mm, fruit mass = 210 – 540, 235 – 595 and 290 – 585 g/ fruit, number of seeds per fruit in = 350 – 580, 410 – 590 and 355 – 560, bulk density = 1.37, 1.30 and 1.40 g/cm3  and real density =   0.49, 0.44 and 0.45 g/cm3 for  “Beta-alpha”, “Hayel” and “Bahi” varieties respectively, bulb mass per fruit = 250 – 550 g/fruit, seed mass per fruit= 15 – 40 g/fruit, rind thickness = 7 – 10 mm and fruit volume = 200 – 500 cm3 for all tested varieties, .Mechanical properties of cucumber fruits: penetration forces = 39.2 – 42.5, N, firmness = 90.1 99.1 100.9 N/cm2 and axial shear-force = 41.5 - 43 N for tested “Beta-alpha”, “Hayel” and “Bahi” varieties.The physical and mechanical properties are used to design of a seed-extractor is given also in this paper

Ligand-based design, synthesis, computational insights, and in vitro studies of novel N-(5-Nitrothiazol-2-yl)-carboxamido derivatives as potent inhibitors of SARS-CoV-2 main protease

The global outbreak of the COVID-19 pandemic provokes scientists to make a prompt development of new effective therapeutic interventions for the battle against SARS-CoV-2. A new series o

Physiological and Neurobehavioral Disturbances Induced by Al2O3 Nanoparticle Intoxication in Nile Tilapia Fish: Benefits of Dietary Chamomile Essential Oil

Despite the usage of nanoparticles (NPs) is rapidly increasing, several experts have noted the risk of their release into ecosystems and their potential negative impacts on biological systems. However, the available studies on the neurobehavioral impacts of aluminum oxide nanoparticles (Al2O3NPs) on aquatic organisms are little. Hence, this study targeted to ascertain the harmful effects of Al2O3NPs on behavioral characteristics and genotoxic and oxidative damages in Nile tilapia fish. In addition, the beneficial role of chamomile essential oil (CEO) supplementation in reducing these effects was also investigated. In the current study, fish were distributed into 4 equal groups (n = 60 fish per group). The control group was fed a plain diet only, the CEO group received a basic diet complemented with CEO at a level of 2 mg/kg diet, the ALNP group received a basic diet and was exposed to an approximate concentration of 1/10th LC50 of ALNPs nearly 5.08 mg/L, and the combination group (ALNPs/ CEO group) received a basal diet coadministered with ALNPs and CEO at the aforementioned percentages. The findings revealed that O. niloticus exhibit neurobehavioral changes along with changes in the level of GABA, monoamines in the brain tissue, and serum amino acid neurotransmitters, besides a reduction of AChE and Na+/K+-ATPase activities. In addition to brain tissue oxidative damage with upregulation of proinflammatory and stress genes, such as HSP70 and caspase-3, supplementation of CEO significantly reduced the negative impacts of ALNPs. These results showed that CEO has neuroprotective, antioxidant, genoprotective, anti-inflammatory, and antiapoptotic properties in fish that have been exposed to ALNPs. Therefore, we advise its usage as a valuable addition to fish diet

Medical prospects of cryptosporidiosis in vivo control using biofabricated nanoparticles loaded with Cinnamomum camphora extracts by Ulva fasciata

Background and Aim: Global efforts are continuing to develop preparations against cryptosporidiosis. This study aimed to investigate the efficacy of biosynthesized Ulva fasciata loading Cinnamomum camphora oil extract on new zinc oxide nanoparticles (ZnONPs shorten to ZnNPs) and silver nanoparticles (AgNPs) as alternative treatments for Cryptosporidium parvum experimental infection in rats. Materials and Methods: Oil extract was characterized by gas chromatography-mass spectrometry, loaded by U. fasciata on ionic-based ZnO and NPs, and then characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. Biosafety and toxicity were investigated by skin tests. A total of 105 C. parvum oocysts/rat were used (n = 81, 2–3 W, 80–120 g, 9 male rats/group). Oocysts shedding was counted for 21 d. Doses of each preparation in addition to reference drug were administered daily for 7 d, starting on post-infection (PI) day (3). Nitazoxanide (100 mg) was used as the reference drug. After 3 weeks, the rats were sacrificed for postmortem examination and histopathological examination. Two blood samples/rat/group were collected on the 21st day. Ethylenediaminetetraacetic acid blood samples were also used for analysis of biochemistry, hematology, immunology, micronucleus prevalence, and chromosomal abnormalities. Results: C. camphora leaves yielded 28.5 ± 0.3 g/kg oil and 20 phycocompounds were identified. Spherical and rod-shaped particles were detected at 10.47–30.98 nm and 18.83–38.39 nm, respectively. ZnNPs showed the earliest anti-cryptosporidiosis effect during 7–17 d PI. Other hematological, biochemical, immunological, histological, and genotoxicity parameters were significantly fruitful; hence, normalized pathological changes induced by infestation were observed in the NPs treatments groups against the infestation-free and Nitazoxanide treated group. Conclusion: C. camphora, U. fasciata, ZnNPs, and AgNPs have refluxed the pathological effects of infection as well as positively improved host physiological condition by its anticryptosporidial immunostimulant regenerative effects with sufficient ecofriendly properties to be proposed as an alternative to traditional drugs, especially in individuals with medical reactions against chemical commercial drugs

Intensification of heat exchanger performance utilizing nanofluids

Heat exchangers are widely utilized in different thermal systems for diverse industrial aspects. The selection of HEx depends on the thermal efficiency, operating load, size, flexibility in operation, compatibility with working fluids, better temperature and flow controls, and comparatively low capital and maintenance costs. Heat transfer intensification of heat exchangers can be fulfilled using passive, active, or combined approaches. Utilizing nanofluids as working fluids for heat exchangers have evolved recently. The performance of heat exchangers employed different nanofluids depends mainly on the characteristics and improvement of thermophysical properties. Regarding the unique behavior of different nanofluids, researchers have attended noteworthy progress. The current study reviews and summarizes the recent implementations carried out on utilizing nanofluids in different types of heat exchangers, including plate heat exchangers, double-pipe heat exchangers, shell and tube heat exchangers, and cross-flow heat exchangers. The results showed that nanofluids with enhanced thermal conductivity, although accompanied by a considerable decrease in the heat capacity and raising viscosity, has resulted in performance enhancement of different heat exchangers types. So, the performance evaluation criterion that combines the thermal enhancement and increases the pumping power for any type of heat exchangers is requisite to evaluate the overall performance properly. The challenges and opportunities for future work of heat transfer and fluid flow for different types of heat exchangers utilizing nanofluids are discussed and presented

Eco-Friendly Disperse Dyeing and Functional Finishing of Nylon 6 Using Supercritical Carbon Dioxide

In this work, a supercritical carbon dioxide assembly was successfully constructed for dyeing Nylon6 fabric. Primary experiments were carried out to confirm the possibility of bringing the dyeing up to factory scale. A series of disperse azo dyes with potential antibacterial activity were applied to dye the fabric under our study in supercritical carbon dioxide (scCO2). The factors affecting the dyeing conditions (i.e., dye concentration, time, temperature and pressure) and functional properties were discussed and compared with those in aqueous dyeing. The comparison revealed that elimination of auxiliary chemicals such as salt, carrier or dispersing agent has no diverse effect on dyeing. The color strength of the dyed fabric evaluated by using K/S measurements increased by increasing dye concentration from 2% to 6% owf. (on weight of fabric). The nylon6 fabrics dyed in supercritical carbon dioxide have good fastness properties, and especially light fastness compared with conventional exhaustion dyeing. Antibacterial activity of the dyed samples under supercritical conditions was evaluated and the results showed excellent antibacterial efficiency