Iranian Journal of Science and Technology, Transactions A: Science最新文献

Naturally derived biopolymers like alginate are widely used for tissue engineering as hydrogels, and their angiogenic properties have led to their use in clinical trials. Myocardial ischemia is a significant concern in the treatment of cardiovascular diseases. In this context, multi-target therapeutic strategies are gaining significant importance, and the present study is designed to prepare alginate nanogels (ANGs) entrapped with bioactive molecules epigallocatechin gallate (EGCG) and 5-azacytidine (5-A). The nanogels were characterized using various physiochemical techniques, including UV-visible spectroscopy, DLS and zeta, FTIR, XRD, HR-SEM, and AFM analysis, indicating the entrapment of both bioactive molecules in ANGs. The antioxidant ability of the nanogels was evaluated using DPPH and superoxide scavenging activity to evaluate their protective effect, and it was indicated that the nanogels have superior antioxidant activity due to the presence of EGCG. To understand the hemocompatibility of the nanogels with bioactive molecules, a hemolysis test was carried out, and the nanogels did not cause any significant hemolysis for the concentrations tested. An ex-vivo copper ascorbate system was used to induce cardiac injury in chicken hearts, and the antioxidant status of heart tissue revealed that nanogels ANGs/EGCG/5-A could maintain an antioxidant status comparable to that of the control group. Histopathological analysis further revealed that nanogels containing EGCG and 5-A could preserve the structural integrity via an antioxidant defence mechanism, thereby protecting the cardiac function. Further in-vivo studies can establish alginate-based nanogels as a therapeutic agent for myocardial injury.

In this study, the applications of the concept of piecewise differential equations, a powerful mathematical tool for addressing different processes occurring at different time intervals, on prey-predator models were discussed. Thanks to this new concept, we aimed to provide a new perspective for prey-predator models in which ecological processes that start with dyadic interactions can also include triadic interactions after a while. More specifically, two prey-predator models were proposed, one dealing with the different scenarios where a second predator was introduced into an environment with a prey and a predator, and the other where an infected prey was introduced into an environment with a prey and a predator. Numerical simulations were carried out in order to have a graphical representation of the different behavior of these two new models under different scenarios. We strongly believe that this study provides a comprehensive overview of piecewise differential equations and contributions to the field of mathematical biology, especially in modeling prey-predator dynamics.

In this paper, we define the new sequence spaces (Ces_p(tilde{mathcal {G}}_q)~ (1le p<infty )) and (Ces_infty (tilde{mathcal {G}}_q)) by using q-Fibonacci band matrix (tilde{mathcal {G}}_q) defined by

(text {where}~ (k,r in mathbb {N}).) We examine some topological properties and some inclusion relation for these spaces. We also make an effort to build a basis for the space (Ces_p(tilde{mathcal {G}}_q)), compute (alpha)-duals of the same space, characterize some matrix classes and study some geometric properties.

Aquaculture contributes to elevated levels of phosphates and nitrates in both water and sediment, leading to reduced biodiversity and a proliferation of pollution-resistant organisms. One significant challenge in developing effective management strategies is the lack of accurate predictions regarding the dispersion and distribution of pollutants. Consequently, modeling water quality and pollutant distribution is crucial for evaluating these impacts. This study aims to spatially model nutrient release from fish breeding cages in the Sisangan region and assess its impact on water quality using the CORMIX numerical model. Conducted in November 2019 in the Caspian Sea, Mazandaran province, the research involved nine sampling stations. Physicochemical parameters were measured using a Conductivity-Temperature-Depth (CTD) device. Nutrient samples, including nitrogen and phosphorus compounds, were collected with a Niskin bottle and analyzed in the laboratory. Field sampling revealed an average TRIX index of 2.3, indicating oligotrophic water conditions but an elevated trophic state. Modeling results demonstrated that nitrogen and phosphorus concentrations decrease with increasing distance from the fish cages. The findings suggest a potential shift from oligotrophic to mesotrophic conditions due to the increased nutrient load from fish farming activities. This underscores the importance of understanding and managing the environmental impacts of marine aquaculture on water quality and ecosystem health. Effective management strategies must be developed to mitigate these impacts and ensure sustainable aquaculture practices.

The Hankel and Toeplitz determinants (H_{2,1}(F_{f^{-1}}/2)) and (T_{2,1}(F_{f^{-1}}/2)) are defined as: (H_{2,1}(F_{f^{-1}}/2):=Gamma _{1}Gamma _{3} -Gamma ^2_{2}) and (T_{2,1}(F_{f^{-1}}/2):=Gamma ^2_{1}-Gamma ^2_{2}), where (Gamma _1, Gamma _2,) and (Gamma _3) are the first, second and third logarithmic coefficients of inverse functions belonging to the class (mathcal {S}) of normalized univalent functions. In this article, we establish sharp inequalities (|H_{2,1}(F_{f^{-1}}/2)|le 1/4), (|H_{2,1}(F_{f^{-1}}/2)| le 1/36), (|T_{2,1}(F_{f^{-1}}/2)|le 5/16) and (|T_{2,1}(F_{f^{-1}}/2)|le 145/2304) for the logarithmic coefficients of inverse functions for the classes of starlike functions and convex functions with respect to symmetric points. The results show an invariance property of the second Hankel determinants (H_{2,1}(F_{f}/2)) and (H_{2,1}(F_{f^{-1}}/2)) of logarithmic coefficients for the classes (mathcal {S}^*_S) and (mathcal {K}_S). Moreover, we exhibit examples showing that the strict inequality in the main results hold.

In this paper we study the existence of weak solutions for a fourth order variable exponent Kirchhoff type problem involving p(z)-biharmonic operator with indefinite weight and no flux boundary condition. The proof of the existence result relies on employing the concept of a Fredholm-type results for a pair of nonlinear operators ((mathfrak {O},mathfrak {S})), in conjunction with the theory of variable exponent Sobolev spaces.

The Chahfirouzeh porphyry copper deposit is situated within the Kerman Cenozoic magmatic arc and forms part of the Urumieh–Dokhtar magmatic belt in southern Iran. Copper mineralization in the deposit is associated to a Miocene diorite/granodiorite stock. The ore–forming process can be categorized into early, main, and late stages. Based on the microthermometry results, the salinities of the fluid system evolved from 5.86 to 16.15 wt% NaCl equivalent in the early stage, through bimodal ranges of 2.4–12.2 and 30.39–42.56 wt% NaCl equivalent in the main stage, and to 8.14–23 wt% NaCl equivalent in the late stage, strongly suggesting that fluid boiling and CO₂ escape occurred during the main stage of the Chahfirouzeh porphyry system. Furthermore, the total homogenization temperatures of fluid inclusions decrease from 327 to 492 °C during the early, to 313–458 °C during the main, and finally to 250–377 °C during the late events. Laser Raman results also show the presence of CO₂ and CH₄ in the main stage fluid inclusion, which may be due to an equilibrium between them linked to the transition from potassic to phyllic alteration. We propose that the phase separation and release of CO₂ could be crucial for enhancing the activities of NaCl and S²⁻ in the fluids, reducing the oxidation of the fluids, and leading to the deposition of metal sulfides and the entrapment of halite–bearing inclusions in the Chahfirouzeh hydrothermal system.

This paper has found a numerical solution of the space fractional bioheat equation during the hyperthermia treatment. The space fractional derivative is used in the Caputo sense of order ((1<mu le 2)). The finite difference method (FDM) and Chebyshev collocation method are implemented to find the numerical results. Shifted Chebyshev polynomials of the first kind and finite difference approximations with a particular choice of collocation points are used to reduce the given problem into a system of algebraic equations. The algorithm being used is stable and convergent. The results are explained by considering the different orders of space fractional derivatives. The numerical results are also described graphically in anomalous and standard form by taking different parameter values. The dimensionless values are used to find all the results. It is observed from the numerical results that the temperature increases as the fractional derivative decreases for the hyperthermia treatment.

The present study investigates the dynamics of natural enemy (predator)-pest (prey) interactions in an agroecosystem. It focuses on the impacts of providing additional food to natural enemies and harvesting intervention on pest populations. A thorough mathematical and numerical analysis is performed to explore various existing equilibria as trivial, natural enemy free and species coexistence. The assessments also explore the emergence of different bifurcations such as saddle-node, transcritical, and Hopf bifurcation. The effct of harvesting rate and additional food on pests and natural enemy populations are highlighted through numerical simulations. The findings indicate that the system’s multiple equilibria, their stability, and various bifurcations are outcomes of changes in harvesting rates and the availability of additional food. This work offers theoretical insights into biological control initiatives, highlighting specific critical values for imposed harvesting. It also suggests optimal strategies for supplying additional food to effectively manage pest populations. This work concludes that making an arbitrary choice of additional food and harvesting could yield entirely contrary outcomes, potentially resulting in an escalation of pest concentrations and the elimination of the natural enemy.

The Anarak Metallogenic Zone is located in the western part of the Central East Iranian Microcontinent. Paleozoic ultramafic ophiolite and metamorphic complexes are the most common rocks in the Anarak region. Sedimentary and volcanic rocks of the Cretaceous and Eocene age cover the Paleozoic rocks. The polymetallic mineralization of the Anarak is often in related to the listvenitization of ultramafic rocks. These hydrothermal deposits are structurally controlled by basement faults. Rose diagrams and Fry analysis of structural data show an E-W trend in the distribution of faults and mineralization in the region. Analysis of the aeromagnetic data characterizes a west-east and northwest-southeast trend for deep faults that control the boundary of the Paleozoic intrusive and ultramafic rocks. The fusion of the multifractal technique and the lineament factor map identified high-potential zones of hydrothermal polymetallic mineralization in the Anarak region. Fieldwork demonstrates a clear relation between the W-E fault zones and the occurrence of polymetallic deposits in the region. The major faults trending west-east, especially the basement faults, play an important role in the distribution of polymetallic deposits in the Anarak region. In addition to their role as conduits for hydrothermal fluids, these faults were crucial in the emplacement of various host rocks, such as ultramafic and intrusive rocks. This study indicates that the combination of multifractal techniques with lineament factor map processing is an inexpensive and effective method of locating high-potential hydrothermal polymetallic mineralization zones, particularly deposits associated with listvenitization.