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Author(s): Syed Shah Alam [sup.1] , Mohammad Masukujjaman [sup.1] , Mohammed Emad Al-Shaikh [sup.2] , Mohd Helmi Ali [sup.1] , Zafir Khan Mohamed Makhbul [sup.1] , Abdullah Sanusi Othman [sup.3] [...], After withdrawing the movement control order (MCO), new variant (Omicron) of COVID-19 returns as an outbreak again. Therefore, consumers are very much informed by various media to be more cautious in visiting shopping malls and spend less time in there. The purpose of this study was to identify the predictors influencing the desire to stay shorter at the shopping mall. This study was conducted in Malaysia, with the application of three psychological theories and one behavioural theory. This is quantitative research based on an online cross-sectional survey design. Data were collected from 296 respondents, by applying the online snowball sampling method through numerous media platforms i.e., Viber, WhatsApp, Messenger, and other apps in three severely affected cities in Malaysia i.e., Selangor state, Putrajaya, and Kuala Lumpur. SmartPLS was used to analyse the data. Using structural equation modelling, this study result shows risk, protection motivation, and fear have a significant effect on the desire to stay a shorter time at the shopping mall. Social norm moderates the association between fear and the desire to spend a shorter time at the shopping mall. These findings, highlight the need for a more empirical study to design more robust strategies, and a safer and risk-free shopping mall environment.

The research interest in nanomaterials preparation from natural products as a green method and their application in various fields applications, tremendous attention has been taken to the green composition of nanoparticles. ZnO can be considered one of the most widely used metal oxides for most requirements of daily used products. In this research ZnO NPs prepared by using Petroselinum crispum (parsley) extract and to make the first study of toxicological evaluation of ZnO NPs their effect aspects on Honey bees (Apis mellifera). ZnO NPs have been charactarized by using SEM, EDX, XRD, UV-Vis and FTIR Spectroscopy. The toxicological evaluation of ZnO NPs has been applied to a honey bee. The lethal ZnO concentration was obtained, and the LC50 range calculation values ​​were changed during 288 hours of feeding to ZnO nanoparticles at different concentrations (25, 50, 250, 500 mg per 100 ml) and the obtained LC50 values changed from 275, decreasing to 162.55 for the research range times after every 24 hours of exposure feeding calculations. In addition, for the group treated with 500 mg of ZnO per 100 ml, higher mortality was observed compared to other concentrations as it increased more than all other items indicating the above concentrations but not with the control group. The ergonomic design for creating a honey bee shelter was first introduced and no similar investigations were found in the literature.

BACKGROUND/AIMS: Performing pediatric lensectomy, anterior vitrectomy with intraocular lens implantation in one session, using a long sclerocorneal tunnel and covering the incision site with 8/0 Vicryl sutures. MATERIALS AND METHODS: This study includes 52 eyes of 30 patients with pediatric cataracts. At the temporal side, the conjunctival peritomy was performed, followed by two long sclerocorneal side ports and the main incision for intraocular lens (IOLs) implantation. At the end of the operation, the side port and the conjunctiva incisions were sutured with 8/0 Vicryl sutures. The IOLs were implanted in children older than 24 months, not in smaller ones. The operations and intraoperative complications were recorded. After the operation, the patients were examined on the 1st postoperative day, then six times for the first 6 months. During follow-ups, the impact of the suture on the anterior segment complications and astigmatism was evaluated. RESULTS: The age of the patients ranged between 2 months and 8 years. The average operation time was 28 ± 6 min. Due to the suture-related complication, neither re-suturing nor stitch removal was carried out; therefore, general anesthesia was not repeated. The average astigmatism value of the children in the postoperative 1st week was 1.5 ± 1.2 D (0.5–4.0). The mean astigmatism value was 0.8 ± 0.5 D (0.5–1.5) in the 3rd postoperative month. CONCLUSION: The long corneoscleral tunnel method has been found safe in pediatric cataract surgery.

This paper delves into a comprehensive analysis of a generalized impulsive discrete reaction–diffusion system under periodic boundary conditions. It investigates the behavior of reactant concentrations through a model governed by partial differential equations (PDEs) incorporating both diffusion mechanisms and nonlinear interactions. By employing finite difference methods for discretization, this study retains the core dynamics of the continuous model, extending into a discrete framework with impulse moments and time delays. This approach facilitates the exploration of finite-time stability (FTS) and dynamic convergence of the error system, offering robust insights into the conditions necessary for achieving equilibrium states. Numerical simulations are presented, focusing on the Lengyel–Epstein (LE) and Degn–Harrison (DH) models, which, respectively, represent the chlorite–iodide–malonic acid (CIMA) reaction and bacterial respiration in Klebsiella. Stability analysis is conducted using Matlab’s LMI toolbox, confirming FTS at equilibrium under specific conditions. The simulations showcase the capacity of the discrete model to emulate continuous dynamics, providing a validated computational approach to studying reaction-diffusion systems in chemical and biological contexts. This research underscores the utility of impulsive discrete reaction-diffusion models for capturing complex diffusion–reaction interactions and advancing applications in reaction kinetics and biological systems.

This work employs the Extended Direct Algebraic Method (EDAM) to solve quadratic and cubic nonlinear Klein–Gordon Equations (KGEs), which are standard models in particle and quantum physics that describe the dynamics of scaler particles with spin zero in the framework of Einstein’s theory of relativity. By applying variables-based wave transformations, the targeted KGEs are converted into Nonlinear Ordinary Differential Equations (NODEs). The resultant NODEs are subsequently reduced to a set of nonlinear algebraic equations through the assumption of series-based solutions for them. New families of soliton solutions are obtained in the form of hyperbolic, trigonometric, exponential and rational functions when these systems are solved using Maple. A few soliton solutions are considered for certain values of the given parameters with the help of contour and 3D plots, which indicate that the solitons exist in the form of dark kink, hump kink, lump-like kink, bright kink and cuspon kink solitons. These soliton solutions are relevant to actual physics, for instance, in the context of particle physics and theories of quantum fields. These solutions are useful also for the enhancement of our understanding of the basic particle interactions and wave dynamics at all levels of physics, including but not limited to cosmology, compact matter physics and nonlinear optics.

This paper introduces a modified Morris–Lecar neuron model that incorporates a memristor with a ReLU-based activation function. The impact of the memristor on the dynamics of the ML neuron model is analyzed using bifurcation diagrams and Lyapunov exponents. The findings reveal chaotic behavior within specific parameter ranges, while increased magnetic strength tends to maintain periodic dynamics. The emergence of various firing patterns, including periodic and chaotic spiking as well as square-wave and triangle-wave bursting is also evident. The modified model also demonstrates multistability across certain parameter ranges. Additionally, the dynamics of a network of these modified models are explored. This study shows that synchronization depends on the strength of the magnetic flux, with synchronization occurring at lower coupling strengths as the magnetic flux increases. The network patterns also reveal the formation of different chimera states, such as traveling and non-stationary chimera states.

We explore an oscillator with nonlinear functions and equilibrium lines that displays chaos. The equilibrium stability and complexity of the oscillator have been analysed and investigated. The presence of multiple equilibrium lines sets it apart from previously reported oscillators. The synchronization of the oscillator is considered as an application for secure communications. An observer is designed by considering a transmitted signal as a state, in other words, by injecting a linear function satisfying Lipschitz’s condition to the proposed oscillator. Moreover, the adaptive control of the new oscillator is obtained.

The aim of the current review is focused on compiling a comprehensive overview of the zirconia surface modification for implant interface osseointegration. Background: The importance of osseointegration for patients has notably gained importance and been accompanied by a dramatic increase in the number of relevant products and procedures over several decades, with a concomitant rise in publications on this topic. An electronic search was conducted across Ovid Medline, complemented by a manual search across individual databases, such as Cochrane, Web of Science databases, and Google Scholar for the purpose of literature analysis on the mentioned topic. The studies were reviewed and compared. This article summarizes the current scientific and clinical opinions through a brief review with regards to the preferred way of zirconia surface treatment and its impact on osseointegration. There are controversies in terms of performing zirconia surface treatment. Surface bio-inertness of zirconia implants result in limited osseointegration compared to titanium implants.

Sinomenine (SN) is a well-documented unique plant alkaloid extracted from many herbal medicines. The present study evaluates the wound healing potentials of SN on dorsal neck injury in rats. A uniform cut was created on Sprague Dawley rats (24) which were arbitrarily aligned into 4 groups receiving two daily topical treatments for 14 days as follows: A, rats had gum acacia; B, rats addressed with intrasite gel; C and D, rats had 30 and 60 mg/ml of SN, respectively. The acute toxicity trial revealed the absence of any toxic signs in rats after two weeks of ingestion of 30 and 300 mg/kg of SN. SN-treated rats showed smaller wound areas and higher wound closure percentages compared to vehicle rats after 5, 10, and 15 days of skin excision. Histological evaluation of recovered wound tissues showed increased collagen deposition, fibroblast content, and decreased inflammatory cells in granulated tissues in SN-addressed rats, which were statistically different from that of gum acacia-treated rats. SN treatment caused positive augmentation of Transforming Growth Factor Beta 1 (angiogenetic factor) in wound tissues, denoting a higher conversion rate of fibroblast into myofibroblast (angiogenesis) that results in faster wound healing action. Increased antioxidant enzymes (SOD and CAT), as well as decreased MDA contents in recovered wound tissues of SN-treated rats, suggest the antioxidant potentials of SN that aid in faster wound recovery. Wound tissue homogenates showed higher hydroxyproline amino acid (collagen content) values in SN-treated rats than in vehicle rats. SN treatment suppressed the production of pro-inflammatory cytokines and increased anti-inflammatory cytokines in the serum of wounded rats. The outcomes present SN as a viable pharmaceutical agent for wound healing evidenced by its positive modulation of the antioxidant, immunohistochemically proteins, hydroxyproline, and anti-inflammatory cytokines.

This paper introduces and explores the dynamics of a novel three-dimensional (3D) fractional map with hidden dynamics. The map is constructed through the integration of a discrete sinusoidal memristive into a discrete Duffing map. Moreover, a mathematical operator, namely, a fractional variable-order Caputo-like difference operator, is employed to establish the fractional form of the map with short memory. The numerical simulation results highlight its excellent dynamical behavior, revealing that the addition of the piecewise fractional order makes the memristive-based Duffing map even more chaotic. It is characterized by distinct features, including the absence of an equilibrium point and the presence of multiple hidden chaotic attractors.

This paper delves into a comprehensive analysis of a generalized impulsive discrete reaction–diffusion system under periodic boundary conditions. It investigates the behavior of reactant concentrations through a model governed by partial differential equations (PDEs) incorporating both diffusion mechanisms and nonlinear interactions. By employing finite difference methods for discretization, this study retains the core dynamics of the continuous model, extending into a discrete framework with impulse moments and time delays. This approach facilitates the exploration of finite-time stability (FTS) and dynamic convergence of the error system, offering robust insights into the conditions necessary for achieving equilibrium states. Numerical simulations are presented, focusing on the Lengyel–Epstein (LE) and Degn–Harrison (DH) models, which, respectively, represent the chlorite–iodide–malonic acid (CIMA) reaction and bacterial respiration in Klebsiella. Stability analysis is conducted using Matlab's LMI toolbox, confirming FTS at equilibrium under specific conditions. The simulations showcase the capacity of the discrete model to emulate continuous dynamics, providing a validated computational approach to studying reaction-diffusion systems in chemical and biological contexts. This research underscores the utility of impulsive discrete reaction-diffusion models for capturing complex diffusion–reaction interactions and advancing applications in reaction kinetics and biological systems. [ABSTRACT FROM AUTHOR]

In nonlinear dynamics, there is a continuous exploration of introducing systems with evidence of chaotic behavior. The presence of nonlinearity within system equations is crucial, as it allows for the emergence of chaotic dynamics. Given that quadratic terms represent the simplest form of nonlinearity, our study focuses on introducing a novel chaotic system characterized by only quadratic nonlinearities. We conducted an extensive analysis of this system’s dynamical properties, encompassing the examination of equilibrium stability, bifurcation phenomena, Lyapunov analysis, and the system’s basin of attraction. Our investigations revealed the presence of eight unstable equilibria, the coexistence of symmetrical strange repeller(s), and the potential for multistability in the system.

(1) Background: The objective of the current investigation was to determine how different dark chocolate concentrations impacted the enamel and dentine microhardness. (2) Methods: Twenty noncarious premolar teeth extracted for orthodontic reasons were used in this study. Each tooth was divided mesiodistally to obtain 40 specimens of enamel and dentine 4 × 4 mm. Initial and final assessments of the surface microhardness of the enamel and dentine were created using a Digital Micro Vickers Hardness Tester (Laryee, Beijing, China) under (0.24 N load for 15 s). Four random groups (n = 10) were created: G1 (control, immersed in artificial saliva), G2 (70%), G3 (85%), and G4 (100% dark chocolate). Each sample underwent four cycles of 60-s immersion in suggested concentrations, followed by 30 min in artificial saliva. The attained values underwent statistical analysis employing SPSS version 26, with the utilization of T-tests and ANOVA. (3) Results: The results revealed a significant, incremental increase in the average microhardness values for enamel, specifically 61.72 ± 22.729, 64.17 ± 23.397, and 109.15 ± 34.625, and for dentin from 57.91 ± 8.332 to 72.29 ± 2.752 and ultimately reaching 88.67 ± 8.602, corresponding to the escalating concentrations of dark chocolate (70%, 85%, and 100%) (p < 0.001). (4) Conclusions: Immersing the specimens in different concentrations of dark chocolate had a significant positive impact on the microhardness of both enamel and dentine.

Decision Support System (DSS) refers to computer systems designed to help with decision making process. DSS usage are now common in both personal and commercial decision making; including those related to the Islamic faith. Simple Applications (Apps) that help with simple decisions such as to ascertain halal statuses are prevalent. To what extent can DSS facilitate more complicated Islamic decision making such as fiqh ruling, hadith classification and zakat or faraid computations? This paper aims to review DSS initiatives (academic and commercial) intended for the more complicated Islamic or Shariah decision making process and to identify the potentials and challenges especially in the contemporary ijtihad of reviewing and certifying the Shariah compliant statuses of Islamic finance products and services. It is expected that the new digital mindset created by IR 4.0, accelerated by the Covid-19 pandemic; paved the way for the huge potential of Islamic DSS; especially in the Islamic Banking and Finance industry. Artificial Intelligence (AI) technology makes it possible to represent Islamic knowledge into computer processable format to enable complex Shariah decision making. The main challenge is to get a human Shariah expert that is capable of translating his/her knowledge into computable format which leads to lack of Islamic DSS(s) in the market that can be utilized to support Shariah related decision making.

The use of the advancements in memristor technology to construct chaotic maps has garnered significant research attention in recent years. The combination of memristors and nonlinear terms provides an effective approach to proposing novel maps. In this study, we have leveraged memristors and sine terms to develop three-dimensional maps, capable of processing special fixed points. Additionally, we have conducted an in depth study of a specific example (TDMM1 map) to demonstrate its dynamics, feasibility, and application for lightweight encryption. Notably, our general approach could be extended to develop higher-dimensional maps, including four- and five-dimensional ones, thereby opening up the possibility to create numerous higher-dimensional maps.

This work employs the Extended Direct Algebraic Method (EDAM) to solve quadratic and cubic nonlinear Klein–Gordon Equations (KGEs), which are standard models in particle and quantum physics that describe the dynamics of scaler particles with spin zero in the framework of Einstein's theory of relativity. By applying variables-based wave transformations, the targeted KGEs are converted into Nonlinear Ordinary Differential Equations (NODEs). The resultant NODEs are subsequently reduced to a set of nonlinear algebraic equations through the assumption of series-based solutions for them. New families of soliton solutions are obtained in the form of hyperbolic, trigonometric, exponential and rational functions when these systems are solved using Maple. A few soliton solutions are considered for certain values of the given parameters with the help of contour and 3D plots, which indicate that the solitons exist in the form of dark kink, hump kink, lump-like kink, bright kink and cuspon kink solitons. These soliton solutions are relevant to actual physics, for instance, in the context of particle physics and theories of quantum fields. These solutions are useful also for the enhancement of our understanding of the basic particle interactions and wave dynamics at all levels of physics, including but not limited to cosmology, compact matter physics and nonlinear optics. [ABSTRACT FROM AUTHOR]

This paper introduces a modified Morris–Lecar neuron model that incorporates a memristor with a ReLU-based activation function. The impact of the memristor on the dynamics of the ML neuron model is analyzed using bifurcation diagrams and Lyapunov exponents. The findings reveal chaotic behavior within specific parameter ranges, while increased magnetic strength tends to maintain periodic dynamics. The emergence of various firing patterns, including periodic and chaotic spiking as well as square-wave and triangle-wave bursting is also evident. The modified model also demonstrates multistability across certain parameter ranges. Additionally, the dynamics of a network of these modified models are explored. This study shows that synchronization depends on the strength of the magnetic flux, with synchronization occurring at lower coupling strengths as the magnetic flux increases. The network patterns also reveal the formation of different chimera states, such as traveling and non-stationary chimera states. [ABSTRACT FROM AUTHOR]

This study examined the heavy metal content in dust storm samples from Erbil, Iraq, along with four other locations. Using ICP-MS, Cd, Ni, Cr, Hg, Pb, Zn, Mn, Cu, Co, Fe and As were determined. The health risks due to exposure to these metals through ingestion, inhalation and dermal contact were assessed for both adults and children. Non-carcinogenic risks were evaluated using the hazard quotient (HQ) and hazard index (HI). Children faced a cumulative risk with HQ > 0.2 for As and Cr and HI > 1. The carcinogenic risk was measured using the carcinogenic risk factor (CRF), which fell below 10–6, indicating low cancer risk. However, children had a higher cancer risk (10−4 to 10−6) for As. The pollution indices revealed varying pollution levels from unpolluted to moderately polluted in the studied areas. Overall, this study highlights potential health risks associated with heavy metal exposure during dust storms, particularly for children, and emphasises the importance of addressing these concerns to safeguard public health. [ABSTRACT FROM AUTHOR]

Reaction–diffusion systems have a broad variety of applications, particularly in biology, and it is well known that fractional calculus has been successfully used with this type of system. However, analyzing these systems using discrete fractional calculus is novel and requires significant research in a diversity of disciplines. Thus, in this paper, we investigate the discrete-time fractional-order Lengyel–Epstein system as a model of the chlorite iodide malonic acid (CIMA) chemical reaction. With the help of the second order difference operator, we describe the fractional discrete model. Furthermore, using the linearization approach, we established acceptable requirements for the local asymptotic stability of the system’s unique equilibrium. Moreover, we employ a Lyapunov functional to show that when the iodide feeding rate is moderate, the constant equilibrium solution is globally asymptotically stable. Finally, numerical models are presented to validate the theoretical conclusions and demonstrate the impact of discretization and fractional-order on system dynamics. The continuous version of the fractional-order Lengyel–Epstein reaction–diffusion system is compared to the discrete-time system under consideration.

A memristor is a two-terminal passive electronic device that exhibits memory of resistance. It is essentially a resistor with memory, hence the name “memristor”. The unique property of memristors makes them useful in a wide range of applications, such as memory storage, neuromorphic computing, reconfigurable logic circuits, and especially chaotic systems. Fixed point-free maps or maps without fixed points, which are different from normal maps due to the absence of fixed points, have been explored recently. This work proposes an approach to build fixed point-free maps by connecting a cosine term and a memristor. Four new fixed point-free maps displaying chaos are reported to illustrate this approach. The dynamics of the proposed maps are verified by iterative plots, bifurcation diagram, and Lyapunov exponents. Because such chaotic maps are highly sensitive to the initial conditions and parameter variations, they are suitable for developing novel lightweight random number generators.

Given the recent advances regarding the studies of discrete fractional calculus, and the fact that the dynamics of discrete-time neural networks in fractional variable-order cases have not been sufficiently documented, herein, we consider a novel class of discrete-time fractional-order neural networks using discrete nabla operator of variable-order. An adequate criterion for the existence of the solution in addition to its uniqueness for such systems is provided with the use of Banach fixed point technique. Moreover, the uniform stability is investigated. We provide at the end two numerical simulations illustrating the relevance of the aforementioned results.

This paper presents a new third-order symmetric difference equation transformed into a 3D discrete symmetric map. The nonlinear dynamics and symmetry of the proposed map are analyzed with two initial conditions for exploring the sensitivity of the map and highlighting the influence of the map parameters on its behaviors, thus comparing the findings. Moreover, the stability of the zero fixed point and symmetry are examined by theoretical analysis, and it is proved that the map generates diverse nonlinear traits comprising multistability, chaos, and hyperchaos, which is confirmed by phase attractors in 2D and 3D space, Lyapunov exponents ( L E s ) analysis and bifurcation diagrams; also, 0-1 test and sample entropy (SampEn) are used to confirm the existence and measure the complexity of chaos. In addition, a nonlinear controller is introduced to stabilize the symmetry map and synchronize a duo of unified symmetry maps. Finally, numerical results are provided to illustrate the findings. [ABSTRACT FROM AUTHOR]

Objectives: Diagnostic reference levels (DRLs) are crucial tools for optimizing radiation exposure during different radiological examinations. This study aimed to establish preliminary DRLs for commonly performed computed tomographic angiography (CTA) examinations in Saudi Arabia. Methods: Data for three types of CTA examinations (cerebral, pulmonary, and lower-extremity) were collected from six medical cities across Saudi Arabia. Data sets related to 723 CTAs with a mean patient weight of 75 kg were analysed in detail. The DRL values were determined based on the 75th, median, and 25th CT dose index volume (CTDIvol) and dose length product (DLP) values. Results: The established DRLs were 1221 mGy cm for cerebral CTAs, 475 mGy cm for pulmonary CTAs, and 1040 mGy cm for lower-extremity CTAs. These values were comparable to those reported in other studies. Conclusions: This study provides preliminary DRLs for three common CTA procedures in Saudi Arabia. The widespread implementation of a low kVp and a high level of image reconstruction (IR) presents an opportunity for further dose reduction. These findings can serve as a foundation for future nationwide DRL surveys and the optimization of CTA imaging protocols in Saudi Arabia. [ABSTRACT FROM AUTHOR]

We explore an oscillator with nonlinear functions and equilibrium lines that displays chaos. The equilibrium stability and complexity of the oscillator have been analysed and investigated. The presence of multiple equilibrium lines sets it apart from previously reported oscillators. The synchronization of the oscillator is considered as an application for secure communications. An observer is designed by considering a transmitted signal as a state, in other words, by injecting a linear function satisfying Lipschitz's condition to the proposed oscillator. Moreover, the adaptive control of the new oscillator is obtained. [ABSTRACT FROM AUTHOR]