Plastics have become an indispensable ingredient of human life. Their enormous use is a matter of great environmental and economic concern, which has motivated the researchers and the technologists ...to induce different degrees of degradations in the plastic. These degradations can be induced in a better way if their mechanistic implications are properly understood. A better understanding of the mechanism for these degradations is also advocated in order to facilitate the proper use of the alternative waste disposal strategies. In view of the facts concerning the plastic degradation, in this review article, we have discussed various types of polymeric degradations along with their mechanisms, which include photo-oxidative degradation, thermal degradation, ozone-induced degradation, mechanochemical degradation, catalytic degradation and biodegradation. This article also discusses the different methods used to study these degradations and the factors that affect these degradations.
Keeping in view the antioxidant property of the polysaccharide gums and antibiotic action of gentamicin, in the present work, an attempt has been made to design tragacanth gum/acacia gum based ...sterile hydrogel loaded with gentamicin for wound dressings applications. These polymers were prepared by the radiation induced crosslinking method and were characterized by AFM, SEM, cryo-SEM, XRD, TGA, DSC and swelling studies. These polymer dressings were found to be mucoadhesive, permeable to H2O/O2 and impermeable to the microorganisms. These dressings absorbed simulated wound fluid 4.62 ± 0.31 g/g gel and showed antioxidant activity 11.79 ± 0.09 μg in F-C assay and 55.66% in DPPH assay.
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Acute necrotizing pancreatitis (ANP) is a common gastrointestinal cause of emergency admissions in dogs and humans and can lead to a systemic inflammatory response syndrome resulting in multiple ...organ dysfunction syndrome. Among the various complications associated with ANP, acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is a major contributor leading to high mortality rates associated with severe acute pancreatitis (AP) in human patients. The incidence of ALI/ARDS in ANP dogs is not well-characterized in spontaneous AP and there are no models to study it in rodent models. Most of the data related to AP comes from rodent models of AP, which may not always represent the true mechanisms occurring in the lungs of dogs or humans with ANP. Therefore, this manuscript provides a review of current and potential models to study the role of pulmonary intravascular macrophages (PIMs) in acute pancreatitis. Recently, we characterized lung inflammation in clinical cases of AP in dogs and found significant recruitment of PIMs which have been credited as pro-inflammatory cells in species such as cattle, horse, pigs, and sheep that normally have them. Considering the pro-inflammatory roles of constitutive or induced PIMs, we investigated whether a well-established mouse model of ANP has induced PIMs. We found induced PIMs in L-arginine-induced ANP in mouse and that MCP-1 is important in PIM induction in this model. Taken together, now we summarize information on spontaneous ANP in dog and a mouse model of induced ANP to study mechanisms of lung dysfunction and the role of PIMs during ANP.
Keeping in view the antioxidant nature of the acacia gum and mucoadhesive nature of carbopol hydrogels, in the present studies, an attempt has been made to explore the potential of these materials in ...designing new hydrogel wound dressings meant for slow release of gentamicin, an antibiotic drug, and to enhance the wound healing potential. The hydrogel films were characterized by SEM, FTIR, XRD and swelling studies. Biomedical properties of hydrogel films like blood compatibility, antioxidant activity, mucoadhesion, antimicrobial activity, oxygen/water vapour permeability, microbial penetration and mechanical properties (tensile strength, burst strength, resilience, relaxation, and folding endurance) have been evaluated. The histological studies of wound healing were also carried out on swiss albino mice of strain Balb C and it has been observed that in case of wounds covered with hydrogel dressings shown faster wound healing, formation of well developed fibroblasts and blood capillaries as compared to open wounds. The results of biomedical properties indicated that hydrogel films are non-thrombogenic, non-haemolytic, antioxidant and mucoadhesive in nature, and are permeable to oxygen and moisture while impermeable to micro-organisms. The hydrogel wound dressings have absorbed (8.772±0.184g/g film) simulated wound fluid. Release of gentamicin drug from wound dressings occurred through Fickian diffusion mechanism in simulated wound fluid.
Image thresholding is one of the most important approaches for image segmentation. Among multilevel thresholding techniques, cross entropy has been widely used by researchers to find multilevel ...threshold values. In multilevel cross entropy thresholding techniques, main target is to find an optimal combination of threshold values at different levels for minimizing the cross entropy. In this paper, Teaching-Learning-based Optimization (TLBO) algorithm is used to find an optimal combination of threshold values at different levels for minimizing the cross entropy. TLBO algorithm is inspired by passing on knowledge within a classroom environment where students first gain knowledge from a teacher and then through mutual interaction. This new proposed approach is called the TLBO-based minimum cross entropy thresholding (TLBO-based MCET) algorithm. The performance of the proposed algorithm is tested on a number of standard test images. For comparative analysis, the results of TLBO-based MCET algorithm are compared with the results of Firefly-based minimum cross entropy thresholding (FF-based MCET), Honey Bee Mating Optimization-based minimum cross entropy thresholding (HBMO-based MCET) and Quantum Particle Swarm Optimization-based minimum cross entropy thresholding (Quantam PSO-based MCET). Comparative analysis is done based on two most popular objective performance measures, Peak Signal to Noise Ratio (PSNR) and Uniformity. From experimental results, it is observed that the proposed method is an efficient and feasible method to search an optimal combination of threshold values at 2nd, 3rd, 4th and 5th levels.
The present problem investigates the two-dimensional disturbances in a homogeneous, isotropic, micropolar thermoelastic saturated porous medium under the purview of Green-Lindsay (GL) theory of ...thermoelasticity. The medium is assumed to be unstrained and unstressed initially and has uniform temperature. The formulation is subjected to a moving thermal shock. Normal mode technique is employed to obtain the exact expressions for the displacement components, stresses, pore pressure and temperature. Numerical computations have been carried out with the help of MATLAB software and the results are illustrated graphically. Comparisons are made to show the effects of time, velocity of the load, micropolar and porous parameters on the resulting quantities. The outcomes point out a strong impact of these parameters on the physical quantities and agree with the boundary conditions. Some particular cases of interest have been deducted from the current investigation to validate the results. The present work is useful and valuable for analysis of problems involving thermal shock, micropolar and poroelastic deformations.
The current study explores two-dimensional disturbances in a nonlocal photothermoelastic semiconducting medium with two temperatures by implementing the Green Naghdi-II theory. The thermal ...conductivity of the medium is assumed to be varying with temperature changes. The formulation is subjected to an inclined mechanical load. A lot of research has been carried out in recent years on photothermoelastic medium, but not much attention has been given to study the dynamical interactions in a nonlocal photothermoelastic medium with two temperatures and variable thermal conductivity under the effect of inclined mechanical load. The analytical solutions of physical field variables such as temperatures, stresses, carrier density and displacement are obtained by using the normal mode analysis method. For a specific material, numerical computations are performed to illustrate the results. The results that were obtained through numerical analysis for the physical quantities are displayed graphically. The comparisons are made among the results obtained by taking into account the different values of time, inclination angle, two temperature parameter, nonlocal parameter, variable thermal conductivity and photothermal elastic constants. Some special cases of interest have been inferred from the present study for validation.
Arsenic, existing in various chemical forms such as arsenate (As(V)) and arsenite (As(III)), demands serious attention in water and environmental contexts due to its significant health risks. It is ...classified as “carcinogenic to humans” by the International Agency for Research on Cancer (IARC) and is listed by the World Health Organization (WHO) as one of the top 10 chemicals posing major public health concerns. This widespread contamination results in millions of people globally being exposed to dangerous levels of arsenic, making it a top priority for the WHO. Chronic arsenic toxicity, known as arsenicosis, presents with specific skin lesions like pigmentation and keratosis, along with systemic manifestations including chronic lung diseases, liver issues, vascular problems, hypertension, diabetes mellitus, and cancer, often leading to fatal outcomes. Therefore, it is crucial to explore novel, cost-effective, and reliable methods with rapid response and improved sensitivities (detection limits). Most of the traditional detection techniques often face limitations in terms of complexity, cost, and the need for sophisticated equipment requiring skilled analysts and procedures, which thereby impedes their practical use, particularly in resource-constrained settings. Colorimetric methods leverage colour changes which are observable and quantifiable using simple instrumentation or even visual inspection. This review explores the colorimetric techniques designed to detect arsenite and arsenate in water. It covers recent developments in colorimetric techniques, and advancements in the role of nanomaterials in colorimetric arsenic detection, followed by discussion on current challenges and future prospects. The review emphasizes efforts to improve sensitivity, selectivity, cost, and portability, as well as the role of advanced materials/nanomaterials to boost the performance of colorimetric assays/sensors towards combatting this pervasive global health concern.
Glioblastoma, an aggressive primary brain tumor, poses a significant challenge owing to its dynamic and intricate tumor microenvironment. This review investigates the innovative integration of ...biosensor-enhanced organ-on-a-chip (OOC) models as a novel strategy for an in-depth exploration of glioblastoma tumor microenvironment dynamics. In recent years, the transformative approach of incorporating biosensors into OOC platforms has enabled real-time monitoring and analysis of cellular behaviors within a controlled microenvironment. Conventional in vitro and in vivo models exhibit inherent limitations in accurately replicating the complex nature of glioblastoma progression. This review addresses the existing research gap by pioneering the integration of biosensor-enhanced OOC models, providing a comprehensive platform for investigating glioblastoma tumor microenvironment dynamics. The applications of this combined approach in studying glioblastoma dynamics are critically scrutinized, emphasizing its potential to bridge the gap between simplistic models and the intricate in vivo conditions. Furthermore, the article discusses the implications of biosensor-enhanced OOC models in elucidating the dynamic features of the tumor microenvironment, encompassing cell migration, proliferation, and interactions. By furnishing real-time insights, these models significantly contribute to unraveling the complex biology of glioblastoma, thereby influencing the development of more accurate diagnostic and therapeutic strategies.
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