Recent Development of Electrolytes for Aqueous Organic Redox Flow Batteries (Aorfbs): Current Status, Challenges, and Prospects.

In recent years, aqueous organic redox flow batteries (AORFBs) have attracted considerable attention due to advancements in grid-level energy storage capacity research. These batteries offer remarkable benefits, including outstanding capacity retention, excellent cell performance, high energy density, and cost-effectiveness. The organic electrolytes in AORFBs exhibit adjustable redox potentials and tunable solubilities in water. Previously, various types of organic electrolytes, such as quinones, organometallic complexes, viologens, redox-active polymers, and organic salts, were extensively investigated for their electrochemical performance and stability. This study presents an overview of recently published novel organic electrolytes for AORFBs in acidic, alkaline, and neutral environments. Furthermore, it delves into the current status, challenges, and prospects of AORFBs, highlighting different strategies to overcome these challenges, with special emphasis placed on their design, composition, functionalities, and cost. A brief techno-economic analysis of various aqueous RFBs is also outlined, considering their potential scalability and integration with renewable energy systems.

Structural Diversity, Spectral Data, and Pharmacological Effects of Genus Nigella.

Nigella is one of the most studied plants because of its pharmacological properties like anti-parasitic, anti-inflammatory, neuro-protective, hepatoprotective, and anti-cancerous. In this study, about 20 species of the genus Nigella were reviewed and among them, N. damascene, N. glandulifera, and N. sativa are widely studied for their phytochemical and pharmacological effects. This review describes the phytochemical composition of the genus Nigella, which constitutes many of the compounds including alkaloids, flavonoids, saponins, and terpenoids. The extracts produced by using different solvents and the isolated compounds displayed a wide range of biological activity. These compounds were identified by different spectral techniques. The spectral detail of some advanced techniques including EIS-MS, UV/VIS, IR, 13 C-NMR, and 1 H-NMR of some important phytoconstituents of Nigella spp. has been compiled for the first time in this review which will be helpful to explore and further investigate the chemical composition of this genus.

Evaluation of post-operative dry eye in upper and lower eyelid reconstruction: A cross-sectional study.

Purpose: In cases of eyelid malignancies requiring full thickness excisional biopsy followed by reconstruction of the created defect, the Meibomian glands are lost. Post-operative varying degrees of dry eye disease (DED) are expected in such patients. The aim was to evaluate the objective and subjective statuses of DED in cases of full thickness eyelid reconstruction following excisional biopsy because of malignancies. Methods: This was a cross-sectional pilot study. Objective and subjective dry eye parameters are assessed in cases of full thickness eyelid reconstruction following excisional biopsy because of malignancies in 37 eyes at 6 months post-operative follow-up. Analysis of variance and Chi square test were used for statistical analysis. Results: When compared with fellow eye, all the parameters were found to be statistically significant (P < 0.0). Subjective assessment of dry eye by ocular surface disease index (OSDI) scoring did not corroborate with the objective data (p 0.00). Lower eyelid reconstruction showed a minimum number of dry eye cases (P > 0.05). Conclusion: Prevalence of post-operative dry eye is more with increasing percentage of full thickness upper eyelid reconstruction. Disparity was found between objective and subjective parameters of dry eye in patients requiring varying percentages of upper eyelid reconstruction because of malignancies.

Central Retinal Artery Occlusion in COVID-Associated Mucormycosis.

Introduction: Significant surge of mucormycosis was reported in the Indian Subcontinent during the second wave of the COVID-19 pandemic. COVID-associated mucormycosis (CAM) was defined as the development of features of mucormycosis with prior or current history of COVID-19 infection. Rapid angioinvasion is an important characteristic of mucormycosis. Authors intended to find out the prevalence of retinal arterial occlusion and its association with vascular embolic occlusion elsewhere in the body among CAM patients in this study. Methods: This was an observational study. All consecutive-confirmed cases of mucormycosis (n = 89) and age-/gender-/risk factor-matched controls (n = 324) admitted in the designated COVID center were included in the study. All cases and controls underwent comprehensive ophthalmological, otorhinological, and neurological examinations. All necessary investigations to support the clinical diagnosis were done. Qualitative data were analyzed using the Chi-square test. Quantitative data for comparison of means between the cases and controls were done using unpaired t-test. Results: Twenty-one (23.59%) patients manifested the defined outcome of central retinal artery occlusion (CRAO). Among age-matched control, with similar diabetic status, none had developed the final outcome as defined (P < 0.05). About 90.47% of subjects with CRAO presented with no perception of light vision. Thirteen subjects (61.9%) with the final outcome developed clinical manifestations of stroke during the course of their illness with radiological evidence of watershed infarction (P = 0.001). Orbital debridement was performed in 9 (42.85%) subjects while orbital exenteration was done in 8 (38.09%) subjects. Conclusions: CRAO in CAM patients was found to have aggressive nature turning the eye blind in a very short period of time. CRAO can serve as a harbinger for subsequent development of more debilitating and life-threatening conditions such as stroke among CAM patients.

Facile synthesis and comparative study of the enhanced photocatalytic degradation of two selected dyes by TiO2-g-C3N4 composite.

Photocatalysis is considered a useful technique employed for the dye degradation through solar light, visible or UV light irradiation. In this study, TiO2, g-C3N4, and TiO2-g-C3N4 nanocomposites were successfully synthesized and studied for their ability to degrade Rhodamine B (RhB) and Reactive Orange 16 (RO-16), when exposed to visible light. The analytical techniques including XRD, TEM, SEM, DRS, BET, XPS, and fluorescence spectroscopy were used to explore the characteristics of all the prepared semiconductors. The photocatalytic performance of synthesized materials has been tested against both the selected dyes, and various experimental parameters were studied. The experimental results demonstrate that, in comparison to other fabricated composites, the TiO2-g-C3N4 composite with the optimal weight ratio of g-C3N4 (15 wt%) to TiO2 has shown outstanding degrading efficiency against RhB (89.62%) and RO-16 (97.20%). The degradation experiments were carried out at optimal conditions such as a catalyst load of 0.07 g, a dye concentration of 50 ppm, and a temperature of 50 ℃ at neutral pH in 90 min. In comparison to pure TiO2 and g-C3N4, the TiO2-g-C3N4, a semiconductor, has shown higher degradation efficiency due to its large surface area and decreased electron-hole recombination. The scavenger study gave an idea about the primary active species (-OH radicals), responsible for dye degradation. The reusability of TiO2-g-C3N4 was also examined in order to assess the composite sustainability.

Biosurfactants in the sustainable eradication of SARS COV-2 from the environmental surfaces.

The COVID-19 outbreak has brought the world, at least, to one consensus that cleanliness is unavoidable under all circumstances. Hands are the main body part to interact with the environment and thus are prone to receive, initiate and propagate the chain of infection. Hand hygiene has, therefore, been most emphasized by experts to interrupt the spread of infection. Various harsh chemicals like synthetic surfactants and alcoholic preparations have been in practice to eradicate and disinfect the germs. This choice may be unsafe and cause a subsequent chain of adversities. Thereby, biosurfactants have been proposed as sustainable, non-toxic and safe surface cleaners cum disinfectants under a wide range of physiological and environmental conditions. The amphiphilic micellar behavior of biosurfactants makes them promising candidates as hygienic surface cleaners and therapeutic carriers. We overview the possibilities of using biosurfactants in different ways against microbial pathogens, in general, and the SARS COV-2, in specific.

Arsenic in drinking water: overview of removal strategies and role of chitosan biosorbent for its remediation.

Accessibility to clean drinking water often remains a crucial task at times. Among other water pollutants, arsenic is considered a more lethal contaminant and has become a serious threat to human life globally. This review discussed the sources, chemistry, distribution, and toxicity of arsenic and various conventional technologies that are in option for its removal from the water system. Nowadays, biosorbents are considered the best option for arsenic-contaminated water treatment. We have mainly focused on the need and potential of biosorbents especially the role of chitosan-based composites for arsenic removal. The chitosan-based sorbents are economically more efficient in terms of their, low toxicity, cost-effectiveness, biodegradability, eco-friendly nature, and reusability. The role of various modification techniques, such as physical and chemical, has also been evaluated to improve the physicochemical properties of biosorbent. The importance of adsorption kinetic and isotherm models and the role of solution pH and pHPZC for arsenic uptake from the polluted water have also been investigated. Some other potential applications of chitosan-based biosorbents have also been discussed along with its sustainability aspect. Finally, some suggestions have been highlighted for further improvements in this field.

Clinical outcome of orbital apex syndrome in COVID associated mucormycosis patients in a tertiary care hospital.

AIM: To share clinical pattern of presentation, the modalities of surgical intervention and the one month post-surgical outcome of rhino-orbito-mucormycosis (ROCM) cases. METHODS: All COVID associated mucormycosis (CAM) patients underwent comprehensive multidisciplinary examination by ophthalmologist, otorhinolaryngologist and physician. Patients with clinical and radiological evidence of orbital apex involvement were included in the study. Appropriate medical and surgical intervention were done to each patient. Patients were followed up one-month post intervention. RESULTS: Out of 89 CAM patients, 31 (34.8%) had orbital apex syndrome. Sixty-six (74.2%) of such patients had pre-existing diabetes mellitus, 18 (58%) patients had prior documented use of steroid use, and 55 (61.8%) had no light perception (LP) presenting vision. Blepharoptosis, proptosis, complete ophthalmoplegia were common clinical findings. Seventeen (19.1%) of such patients had variable amount of cavernous sinus involvement. Endoscopic debridement of paranasal sinuses and orbit with or without eyelid sparing limited orbital exenteration was done in most cases, 34 (38.2%) patients could retain vision in the affected eye. CONCLUSION: Orbital apex involvement in CAM patients occur very fast. It not only leads to loss of vision but also sacrifice of the eyeball, orbital contents and eyelids. Early diagnosis and prompt intervention can preserve life, vision and spare mutilating surgeries.

Arsenic removal approaches: A focus on chitosan biosorption to conserve the water sources.

Globally, millions of people have no access to clean drinking water and are either striving for that or oppressed to intake polluted water. Arsenic is considered one of the most hazardous contaminants in water bodies that reaches there due to various natural and anthropogenic activities. Modified chitosan has gained much attention from researchers due to its potential for arsenic removal. This review focuses on the need and potential of chitosan-based biosorbents for arsenic removal from water systems. Chitosan is a low-cost, abundant, biodegradable biopolymer that possesses unique structural aspects and functional sites for the adsorption of contaminants like arsenic species from contaminated water. The chitosan-based biosorbents had also been modified using various techniques to enhance their arsenic removal efficiencies. This article reviews various forms of chitosan and parameters involved in chitosan modification which eventually affect the arsenic removal efficiency of the resultant sorbents. The literature revealed that the modified chitosan-based sorbents could express higher adsorption efficiency compared to those prepared from native chitosan. The sustainability of the chitosan-based sorbents has also been considered in terms of reusability. Finally, some recommendations have been underlined for further improvements in this domain.

Recent developments in polysaccharide-based electrospun nanofibers for environmental applications.

Electrospinning has become an inevitable approach to produce nanofibrous structures for diverse environmental applications. Polysaccharides, due to their variety of types, biobased origins, and eco-friendly, and renewable nature are wonderful materials for the said purpose. The present review discusses the electrospinning process, the parameters involved in the formation of electrospun nanofibers in general, and the polysaccharides in specific. The selection of materials to be electrospun depends on the processing conditions and properties deemed desirable for specific applications. Thereby, the conditions to electrospun polysaccharides-based nanofibers have been focused on for possible environmental applications including air filtration, water treatment, antimicrobial treatment, environmental sensing, and so forth. The polysaccharide-based electrospun membranes, for instance, due to their active adsorption sites could find significant potential for contaminants removal from the aqueous systems. The study also gives some recommendations to overcome any shortcomings faced during the electrospinning and environmental applications of polysaccharide-based matrices.

Effect of metal atom in zeolitic imidazolate frameworks (ZIF-8 & 67) for removal of Pb2+ & Hg2+ from water.

Heavy metals especially lead (Pb) and mercury (Hg) are recognized as most emerging pollutants in underground water and are major threat to public health around the world. Major challenge to mitigate water pollution is construction of effective materials containing a host of deceivingly accessible high-density and high-level efficiency. Herein, we have synthesized two metal-organic frameworks (MOFs) with efficient porosity showing the right combination of structures. Representatively, ZIF-8 and ZIF-67 were designed by reacting Zn, Co salts with 2-methyl imidazole showing superior efficacy in removing Pb and Hg (1978.63&1436.11 mg/g respectively) from water. These adsorbents displayed high distribution values permitting them to quickly reduce concentration level of Pb2+, Hg2+ below permissible limit (Pb = 0-15 µg/L, Hg = 1-10 µg/L). EDX, FTIR analysis revealed that Pb2+, Hg2+ bound through weak interactions. Results presented here have shown extraordinary potential with high environmental remediation performance having 99.5% and 98.1% removal efficiency for lead & mercury respectively. Results revealed that adsorbents have same organic linker that identifies same morphology required for adsorption. The difference in adsorption capacity and porosity (ZIF-8 = 937&1370 m2/g, ZIF-67 = 1289&1889 m2/g) are deliberately caused due to presence of metal atoms having different electronic distribution, as cobalt in ZIF-67 and in case of ZIF-8 zinc metal.

Recent developments in chitosan encapsulation of various active ingredients for multifunctional applications.

Microencapsulation being an emerging technique has provided effective solution to the challenges faced by pharmaceutical, cosmetic, food agriculture and textile industries to deliver ingredients in their active forms to the target sites. Chitosan is a non-toxic, biodegradable and biocompatible amino polysaccharide which makes it useful for the encapsulation of various active ingredients with potential applications. Chitosan coating on food products, for example, gives them protection from possible antimicrobial attacks, antioxidants and extended shelf life. Likewise, its coating on pharmaceutics has valuable applications in preserving drug and their targeted delivery. In this review, we discuss the formation of chitosan, its properties, microencapsulation process, micro-capsular morphologies, selection of core and shell materials in addition to the process of chitosan encapsulation of various active ingredients and their applications in various fields of science and technology.

Development of sustainable magnetic chitosan biosorbent beads for kinetic remediation of arsenic contaminated water.

We report the preparation of both control chitosan and magnetic chitosan beads as biosorbents using chitosan as matrix and magnetite (Fe3O4) nanoparticles as reinforcement followed by detailed advanced characterization. The batch trials were performed to study the adsorption kinetics of biosorbents by removing As(III) and As(V) species from water systems. The experimental data was inserted into Langmuir and Freundlich's isotherms to undertake the mechanism and adsorption capacity of the test biosorbents. Under Langmuir's isotherm, maximum monolayer adsorption capacity (qmax) of the biosorbent was observed to be 73.69 and 79.49 mg/g for As(III) and As(V) species, respectively, under specified conditions. The optimum doses of 1.5 and 2 g/L of MCBB at pH 6.7 showed 99.5 and 99% removal of As(V) and As(III), respectively. The analysis demonstrated that the biosorption process obeyed pseudo 2nd order kinetics with linear regression coefficient (R2) of >0.999. The regeneration and reusability of biosorbents were also assessed.