The influence of nanoclay on the impact damage resistance of carbon fibre–epoxy composites has been investigated using the low-velocity impact and compression after impact (CAI) tests. The ...load–energy vs. time relations were analyzed to gain insight into the damage behaviours of the materials. The CFRPs containing organoclay brought about significant improvement in impact damage resistance and damage tolerance in the form of smaller damage area, higher residual strength and higher threshold energy level. The presence of nanoclay in the epoxy matrix induced the transition of failure mechanisms of CFRP laminates during the CAI test, from the brittle buckling mode to more ductile, multi-layer delamination mode. Addition of 3
wt% clay was shown to be an optimal content for the highest damage resistance.
Epilepsy is a prevalent neurological disorder with considerable risks, including physical impairment and irreversible brain damage from seizures. Given these challenges, the urgency for prompt and ...accurate seizure detection cannot be overstated. Traditionally, experts have relied on manual EEG signal analyses for seizure detection, which is labor-intensive and prone to human error. Recognizing this limitation, the rise in deep learning methods has been heralded as a promising avenue, offering more refined diagnostic precision. On the other hand, the prevailing challenge in many models is their constrained emphasis on specific domains, potentially diminishing their robustness and precision in complex real-world environments. This paper presents a novel model that seamlessly integrates the salient features from the time-frequency domain along with pivotal statistical attributes derived from EEG signals. This fusion process involves the integration of essential statistics, including the mean, median, and variance, combined with the rich data from compressed time-frequency (CWT) images processed using autoencoders. This multidimensional feature set provides a robust foundation for subsequent analytic steps. A long short-term memory (LSTM) network, meticulously optimized for the renowned Bonn Epilepsy dataset, was used to enhance the capability of the proposed model. Preliminary evaluations underscore the prowess of the proposed model: a remarkable 100% accuracy in most of the binary classifications, exceeding 95% accuracy in three-class and four-class challenges, and a commendable rate, exceeding 93.5% for the five-class classification.
Anthocleista vogelii Planch is a medicinal plant traditionally used in West Africa for the management and treatment of diabetes mellitus.
To determine the antidiabetic activities of chloroform ...fraction (CF) of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes.
Inhibitory activities of CF against α-amylase and α-glucosidase activities were determined in vitro. Three weeks old rats were fed with high-fat diet for 9 weeks to induce obesity prior to further induction of diabetes using alloxan (150 mg/kg body weight, i.p.). Blood glucose levels and body weight were measured every 7 days throughout the experiment. Glucose tolerance was assessed in normal and CF-treated rats on day 21. Terminal blood samples were collected from sacrificed animals for the measurement of serum insulin levels. Pancreases were excised from treated and untreated animals for histopathological examination.
LCMS/MS chromatographic profile of CF via positive and negative modes revealed 13 and 23 compounds respectively. Further analysis revealed quebrachitol (QCT), loganin, sweroside, oleoside 11-methyl ester and ferulic acid, which have been previously reported for their antidiabetic activities, as constituents of CF. CF inhibited activities of α-amylase (IC50 = 51.60 ± 0.92 µg/ml) and α-glucosidase (IC50 = 5.86 ± 0.97 µg/ml) in a dose-dependent manner. Treatment of animals with obesity-diabetes with 100 and 200 mg/kg CF significantly improved glucose tolerance (P < 0.001) and enhanced serum insulin levels (P < 0.05) compared to diabetic control rats.
Antidiabetic activities of CF might be mediated via inhibition of α-amylase and α-glucosidase activities, elevation of serum insulin concentration, and enhancement of insulin and leptin sensitivity in obesity-diabetes rats. This study further substantiates the traditional use of A. vogelii in the management and treatment of diabetes in Africa and encourages further studies to investigate its mechanism of action.
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The aim of this work is to contribute to the research in finding lead compounds for clinical use, to identify new drugs that target the SARS-CoV-2 virus main protease (Mpro). In this ...study, we used molecular docking strategies to analyze 2.5-diaminobenzophenone compounds against Malaria and to compare results with the Nelfinavir as a FDA-approved HIV-1 protease inhibitor recommended for the treatment of COVID-19. These efforts identified the potential compounds against SAR-COV-2 Mpro with the docking scores ranges from −6.1 to −7.75 kcal/mol, which exhibited better interactions than the Nelfinavir. Among thirty-six studied, compounds 20c, 24c, 30c, 34c, 35c and 36c showed the highest affinity and involved in forming hydrophobic interactions with Glu166, Thr24, Thr25, and Thr26 residues and forming H-bonding interactions with Gln189, Cys145, and His41residues. Pharmacokinetic properties and toxicity (ADMET) were also determined for identified compounds. This study result in the identification of two compounds 35 and 36 having high binding affinity, good pharmacokinetics properties and lowest toxicity. The structural stability and dynamics of lead compounds within the active site of 3CLpro was also examined using molecular dynamics (MD) simulation. Essential dynamics demonstrated that the two complexes remain stable during the entire duration of simulation. We have shown that these two lead molecules would have the potential to act as promising drug-candidates and would be of interest as starting point for designing compounds against the SARS-CoV-2.
This paper reports the alignment of multi-walled carbon nanotubes (MWCNTs) in an epoxy matrix as a result of DC electric fields applied during composite curing. Optical microscopy and polarized Raman ...spectroscopy are used to confirm the CNT alignment. The alignment of CNTs gives rise to much improved electrical conductivity, elastic modulus and quasi-static fracture toughness compared to those with CNTs of random orientation. An extraordinarily low electrical percolation threshold of about 0.0031vol% is achieved when measured along the alignment, which is more than one order of magnitude lower than 0.034vol% with random orientation or that measured perpendicular to the aligned CNTs. The examination of the fracture surfaces identifies pertinent toughening mechanisms in aligned CNT composites, namely crack tip deflection and CNT pullout. The significance of this paper is that the technique employed here can tailor the physical, mechanical and fracture properties of bulk nanocomposites even at a very low CNT concentration.
The biological, chemical, and in silico properties of methanol and dichloromethane (DCM) extracts of Alhagi maurorum roots with respect to the antioxidant, enzyme inhibition, and phytochemical ...composition were evaluated. Total bioactive contents were determined spectrophotometrically, and the individual secondary metabolites composition was assessed via ultra-high-performance liquid chromatography mass spectrometry (UHPLC-MS) analysis. Antioxidant capacities were evaluated using a panoply of assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging, ferric reducing antioxidant power (FRAP), cupric reducing antioxidant power (CUPRAC), phosphomolybdenum total antioxidant capacity (TAC), and metal chelating activity (MCA)). The enzyme inhibition potential was studied against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, α-glucosidase, tyrosinase, urease and lipoxygenase (LOX) enzymes. The methanol extract was found to contain higher total phenolic (105.91 mg GAE/g extract) and flavonoid (2.27 mg RE/g extract) contents which can be correlated to its more substantial antioxidant potential as well as AChE, BChE, tyrosinase and α-glucosidase inhibition. However, the DCM extract was the most effective against α-amylase (1.86 mmol ACAE/g extract) enzyme inhibition. The UHPLC-MS analysis of methanol extract identified the tentative presence of a total of 18 secondary metabolites, including flavonoids, saponins, phenolic and terpenoid derivatives. Three compounds named emmotin A, luteolin 5,3'-dimethyl ether, and preferrugone were further investigated for their in silico molecular docking studies against the tested enzymes. The selected compounds were found to have higher binding interaction with AChE followed by BChE, α-glucosidase, α-amylase, and tyrosinase. The results of the present study have demonstrated A. mauroram to be considered as a lead source of natural antioxidant and enzyme inhibitor compounds.
Hypertension is defined as the persistence of elevated blood pressure in the circulation system. The renin-angiotensin-aldosterone system is a major modulator of blood pressure. Among the risk ...factors of cardiovascular disease, hypertension is the most preventable and treatable, with drugs such as ACE inhibitors. Many ACE inhibitors are known to have undesirable side effects and hence, natural alternatives are being sought. Dietary polyphenols, particularly ellagitannins, are derived from plant products and are known to exhibit a variety of bioactivities. Geraniin, an ellagitannin has been shown to have antihypertensive activity in animal experiments. It is speculated that the metabolites of geraniin are responsible for its ACE inhibitory activity. We have performed in vitro ACE inhibition and in silico studies with geraniin and its metabolites (ellagic acid, urolithins). Our studies confirm that ellagic acid exhibited similar inhibitory potential to ACE as the positive control captopril.
The mechanical and thermo-mechanical properties of polybenzoxazine nanocomposites containing multi-walled carbon nanotubes (MWCNTs) functionalized with surfactant are studied. The results are ...specifically compared with the corresponding properties of epoxy-based nanocomposites. The CNTs bring about significant improvements in flexural strength, flexural modulus, storage modulus and glass transition temperature, Tg, of CNT/polybenzoxazine nanocomposites at the expense of impact fracture toughness. The surfactant treatment has a beneficial effect on the improvement of these properties, except the impact toughness, through enhanced CNT dispersion and interfacial interaction. The former four properties are in general higher for the CNT/polybenzoxazine nanocomposites than the epoxy counterparts, and vice versa for the impact toughness. The addition of CNTs has an ameliorating effect of lowering the coefficient of thermal expansion (CTE) of polybenzoxazine nanocomposites in both the regions below and above Tg, whereas the reverse is true for the epoxy nanocomposites. This observation has a particular implication of exploiting the CNT/polybenzoxazine nanocomposites in applications requiring low shrinkage and accurate dimensional control.
Fruit drop is a key issue with date palm cultivars that can be addressed with a variety of methods and strategies. Foliar application of macronutrients can be more effective in inhibiting fruit drop ...and improving the quality of date fruits. The current study was carried out to investigate the possible role of potassium (K) and urea to reduce fruit drop and improve the fruit quality of “Dhakki” date palm. It was conducted in a complete randomised block design with seven treatments and three replications at Pakistan's Agricultural Research Institute, Dera Ismail Khan. The treatments used were: (i) Control (distilled water spray); (ii) Potassium sulphate (K2SO4) at 1 %; (iii) K2SO4 at 1 % + Urea at 2 %; (iv) K2SO4 at 2 %; (v) K2SO4 at 2 % + Urea at 2 %; (vi) K2SO4 at 3 % and; (vii) K2SO4 at 3 % + Urea at 2 %. All the concentrations were sprayed at Kimri stage of fruit development during two consecutive growing seasons. Twenty-one date palms of equal size and age were chosen for the assessments to measure percent fruit drop and other physicochemical variables, including fruit length, fruit diameter, fruit weight, pulp percentage, yield/bundle, pH, total soluble solids (TSS), K content in fruit, and all sugars (percent) of harvested date fruit. The results revealed that bunch spray of K significantly affected all the parameters during both seasons. Application of K2SO4 alone and in combination with urea not only effectively reduced the fruit drop but also improved fruit quality in date where, K2SO4 applied at 2 % combined with urea was the best concentration in reducing fruit drop, enhancing other physicochemical attributes, and improving fruit quality of “Dhakki” date palm. This study may effectively contribute to reduce the fruit drop and enhance the fruit quality by using K and urea, enabling farmers to improve the date yield and increase economic growth.
Particle swarm optimizer is one of the searched based stochastic technique that has a weakness of being trapped into local optima. Thus, to tradeoff between the local and global searches and to avoid ...premature convergence in PSO, a new dynamic quantum-based particle swarm optimization (DQPSO) method is proposed in this work. In the proposed method a beta probability distribution technique is used to mutate the particle with the global best position of the swarm. The proposed method can ensure the particles to escape from local optima and will achieve the global optimum solution more easily. Also, to enhance the global searching capability of the proposed method, a dynamic updated formula is proposed that will keep a good balance between the local and global searches. To evaluate the merit and efficiency of the proposed DQPSO method, it has been tested on some well-known mathematical test functions and a standard benchmark
problem known as Loney’s solenoid design.
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