A review on fluoride contamination in groundwater and human health implications and its remediation: A sustainable approaches.

Contamination of drinking water due to fluoride (F-) is a major concern worldwide. Although fluoride is an essential trace element required for humans, it has severe human health implications if levels exceed 1.5 mg. L-1 in groundwater. Several treatment technologies have been adopted to remove fluoride and reduce the exposure risk. The present article highlights the source, geochemistry, spatial distribution, and health implications of high fluoride in groundwater. Also, it discusses the underlying mechanisms and controlling factors of fluoride contamination. The problem of fluoride-contaminated water is more severe in India's arid and semiarid regions than in other Asian countries. Treatment technologies like adsorption, ion exchange, precipitation, electrolysis, electrocoagulation, nanofiltration, coagulation-precipitation, and bioremediation have been summarized along with case studies to look for suitable technology for fluoride exposure reduction. Although present technologies are efficient enough to remove fluoride, they have specific limitations regarding cost, labour intensity, and regeneration requirements.

Microbial synthesis of titanium dioxide nanoparticles and their importance in wastewater treatment and antimicrobial activities: a review.

Nanotechnology (NT) and nanoparticles (NPs) have left a huge impact on every field of science today, but they have shown tremendous importance in the fields of cosmetics and environmental cleanup. NPs with photocatalytic effects have shown positive responses in wastewater treatment, cosmetics, and the biomedical field. The chemically synthesized TiO2 nanoparticles (TiO2 NPs) utilize hazardous chemicals to obtain the desired-shaped TiO2. So, microbial-based synthesis of TiO2 NPs has gained popularity due to its eco-friendly nature, biocompatibility, etc. Being NPs, TiO2 NPs have a high surface area-to-volume ratio in addition to their photocatalytic degradation nature. In the present review, the authors have emphasized the microbial (algae, bacterial, fungi, and virus-mediated) synthesis of TiO2 NPs. Furthermore, authors have exhibited the importance of TiO2 NPs in the food sector, automobile, aerospace, medical, and environmental cleanup.

Deeper insight into ferroptosis: association with Alzheimer's, Parkinson's disease, and brain tumors and their possible treatment by nanomaterials induced ferroptosis.

Ferroptosis is an emerging and novel type of iron-dependent programmed cell death which is mainly caused by the excessive deposition of free intracellular iron in the brain cells. This deposited free iron exerts a ferroptosis pathway, resulting in lipid peroxidation (LiPr). There are mainly three ferroptosis pathways viz. iron metabolism-mediated cysteine/glutamate, and LiPr-mediated. Iron is required by the brain as a redox metal for several physiological activities. Due to the iron homeostasis balance disruption, the brain gets adversely affected which further causes neurodegenerative diseases (NDDs) like Parkinson's and Alzheimer's disease, strokes, and brain tumors like glioblastoma (GBS), and glioma. Nanotechnology has played an important role in the prevention and treatment of these NDDs. A synergistic effect of nanomaterials and ferroptosis could prove to be an effective and efficient approach in the field of nanomedicine. In the current review, the authors have highlighted all the latest research in the field of ferroptosis, specifically emphasizing on the role of major molecular key players and various mechanisms involved in the ferroptosis pathway. Moreover, here the authors have also addressed the correlation of ferroptosis with the pathophysiology of NDDs and theragnostic effect of ferroptosis and nanomaterials for the prevention and treatment of NDDs.

Use of biogenic silver nanoparticles on the cathode to improve bioelectricity production in microbial fuel cells.

To date, research on microbial fuel cells (MFCs) has. focused on the production of cost-effective, high-performance electrodes and catalysts. The present study focuses on the synthesis of silver nanoparticles (AgNPs) by Pseudomonas sp. and evaluates their role as an oxygen reduction reaction (ORR) catalyst in an MFC. Biogenic AgNPs were synthesized from Pseudomonas aeruginosa via facile hydrothermal synthesis. The physiochemical characterization of the biogenic AgNPs was conducted via scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-visible spectrum analysis. SEM micrographs showed a spherical cluster of AgNPs of 20-100 nm in size. The oxygen reduction reaction (ORR) ability of the biogenic AgNPs was studied using cyclic voltammetry (CV). The oxygen reduction peaks were observed at 0.43 V, 0.42 V, 0.410 V, and 0.39 V. Different concentrations of biogenic AgNPs (0.25-1.0 mg/cm2) were used as ORR catalysts at the cathode in the MFC. A steady increase in the power production was observed with increasing concentrations of biogenic AgNPs. Biogenic AgNPs loaded with 1.0 mg/cm2 exhibited the highest power density (PDmax) of 4.70 W/m3, which was approximately 26.30% higher than the PDmax of the sample loaded with 0.25 mg/cm2. The highest COD removal and Coulombic efficiency (CE) were also observed in biogenic AgNPs loaded with 1.0 mg/cm2 (83.8% and 11.7%, respectively). However, the opposite trend was observed in the internal resistance of the MFC. The lowest internal resistance was observed in a 1.0 mg/cm2 loading (87 Ω), which is attributed to the high oxygen reduction kinetics at the surface of the cathode by the biogenic AgNPs. The results of this study conclude that biogenic AgNPs are a cost-effective, high-performance ORR catalyst in MFCs.

Insight into the environmental fate, hazard, detection, and sustainable degradation technologies of chlorpyrifos-an organophosphorus pesticide.

Pesticides play a critical role in terms of agricultural output nowadays. On top of that, pesticides provide economic support to our farmers. However, the usage of pesticides has created a public health issue and environmental hazard. Chlorpyrifos (CPY), an organophosphate pesticide, is extensively applied as an insecticide, acaricide, and termiticide against pests in various applications. Environmental pollution has occurred because of the widespread usage of CPY, harming several ecosystems, including soil, sediment, water, air, and biogeochemical cycles. While residual levels in soil, water, vegetables, foodstuffs, and human fluids have been discovered, CPY has also been found in the sediment, soil, and water. The irrefutable pieces of evidence indicate that CPY exposure inhibits the choline esterase enzyme, which impairs the ability of the body to use choline. As a result, neurological, immunological, and psychological consequences are seen in people and the natural environment. Several research studies have been conducted worldwide to identify and develop CPY remediation approaches and its derivatives from the environment. Currently, many detoxification methods are available for pesticides, such as CPY. However, recent research has shown that the breakdown of CPY using bacteria is the most proficient, cost-effective, and sustainable. This current article aims to outline relevant research events, summarize the possible breakdown of CPY into various compounds, and discuss analytical summaries of current research findings on bacterial degradation of CPY and the potential degradation mechanism.

A comprehensive appraisal of mechanism of anti-CRISPR proteins: an advanced genome editor to amend the CRISPR gene editing.

The development of precise and controlled CRISPR-Cas tools has been made possible by the discovery of protein inhibitors of CRISPR-Cas systems, called anti-CRISPRs (Acrs). The Acr protein has the ability to control off-targeted mutations and impede Cas protein-editing operations. Acr can help with selective breeding, which could help plants and animals improve their valuable features. In this review, the Acr protein-based inhibitory mechanisms that have been adopted by several Acrs, such as (a) the interruption of CRISPR-Cas complex assembly, (b) interference with target DNA binding, (c) blocking of target DNA/RNA cleavage, and (d) enzymatic modification or degradation of signalling molecules, were discussed. In addition, this review emphasizes the applications of Acr proteins in the plant research.

A Review of Approaches to the Metallic and Non-Metallic Synthesis of Benzimidazole (BnZ) and Their Derivatives for Biological Efficacy.

Heterocyclic compounds are significant lead drug candidates based on their various structure-activity relationships (SAR), and their use in pharmaceutics is constantly developing. Benzimidazole (BnZ) is synthesized by a condensation reaction between benzene and imidazole. The BnZ structure consists of two nitrogen atoms embedded in a five-membered imide ring which is fused with a benzene ring. This review examines the conventional and green synthesis of metallic and non-metallic BnZ and their derivatives, which have several potential SARs, along with a wide range of pharmacological properties, including anti-cancer, anti-inflammatory, anti-microbial, anti-tubercular, and anti-protozoal properties. These compounds have been proven by pharmacological investigations to be efficient against different strains of microbes. Therefore, in this review, the structural variations of BnZ are listed along with various applications, predominantly related to their biological activities.

Towards further understanding the applications of endophytes: enriched source of bioactive compounds and bio factories for nanoparticles.

The most significant issues that humans face today include a growing population, an altering climate, an growing reliance on pesticides, the appearance of novel infectious agents, and an accumulation of industrial waste. The production of agricultural goods has also been subject to a great number of significant shifts, often known as agricultural revolutions, which have been influenced by the progression of civilization, technology, and general human advancement. Sustainable measures that can be applied in agriculture, the environment, medicine, and industry are needed to lessen the harmful effects of the aforementioned problems. Endophytes, which might be bacterial or fungal, could be a successful solution. They protect plants and promote growth by producing phytohormones and by providing biotic and abiotic stress tolerance. Endophytes produce the diverse type of bioactive compounds such as alkaloids, saponins, flavonoids, tannins, terpenoids, quinones, chinones, phenolic acids etc. and are known for various therapeutic advantages such as anticancer, antitumor, antidiabetic, antifungal, antiviral, antimicrobial, antimalarial, antioxidant activity. Proteases, pectinases, amylases, cellulases, xylanases, laccases, lipases, and other types of enzymes that are vital for many different industries can also be produced by endophytes. Due to the presence of all these bioactive compounds in endophytes, they have preferred sources for the green synthesis of nanoparticles. This review aims to comprehend the contributions and uses of endophytes in agriculture, medicinal, industrial sectors and bio-nanotechnology with their mechanism of action.

Molecular characterization of azoreductase and its potential for the decolorization of Remazol Red R and Acid Blue 29.

Azoreductase is a reductive enzyme that efficiently biotransformed textile azo dyes. This study demonstrated the heterologous overexpression of the azoreductase gene in Escherichia coli for the effective degradation of Remazol Red-R and Acid-Blue 29 dyes. The AzK gene of Klebsiella pneumoniae encoding a ≈22 kDa azoreductase enzyme was cloned into the pET21+C expression vector. The inoculum size of 1.5%, IPTG concentration of 0.5 mM, and incubation time of 6 h were optimized by response surface methodology a statistical tool. The crude extract showed 76% and 74%, while the purified enzyme achieved 94% and 93% decolorization of RRR and AB-29, respectively in 0.3 h. The reaction kinetics showed that RRR had a Km and Vmax value of 0.058 mM and 1416 U mg-1, respectively at an NADH concentration of 10 mM. HPLC and GC-MS analyses showed that RRR was effectively bio-transformed by azoreductase to 2-[3-(hydroxy-amino) benzene-1-sulfonyl and AB-29 to aniline and 3-nitrosoaniline. This study explored the potential of recombinant azoreductase isolated from K. pneumoniae in the degradation of toxic textile azo dyes into less toxic metabolites.

Magnetic sporopollenin supported magnesium nanoparticles for removal of tetracycline as an emerging contaminant from water.

Since the release of antibiotics as emerging contaminants into the environmental water can cause severe difficulties for human health, their removal from the water is necessary. In this regard, a novel environmentally friendly adsorbent was developed based on green sporopollenin, which was magnetized and modified with magnesium oxide nanoparticles to produce MSP@MgO nanocomposite. The newly developed adsorbent was applied to remove tetracycline antibiotic (TC) from aqueous media. The surface morphology of the MSP@MgO nanocomposite was characterized using FTIR, XRD, EDX, and SEM techniques. The effective parameters of the removal process were studied, and it was confirmed that the chemical structure of TC was highly affected by changes in pH solution due to different pKa; therefore, the results showed that pH 5 was the optimum. Also, the maximum sorption capacity of MSP@MgO for TC for adsorption was obtained at 109.89 mg.g-1. In addition, the adsorption models were investigated, and the process was fitted with the Langmuir model. Thermodynamic parameters showed that the process was spontaneous (ΔG < 0), endothermic (ΔH > 0) and the adsorption mechanism was following the physisorption mechanism at room temperature.

An inclusive outlook on the fate and persistence of pesticides in the environment and integrated eco-technologies for their degradation.

Intensive and inefficient exploitation of pesticides through modernized agricultural practices has caused severe pesticide contamination problems to the environment and become a crucial problem over a few decades. Due to their highly toxic and persistent properties, they affect and get accumulated in non-target organisms, including microbes, algae, invertebrates, plants as well as humans, and cause severe issues. Considering pesticide problems as a significant issue, researchers have investigated several approaches to rectify the pesticide contamination problems. Several analyses have provided an extensive discussion on pesticide degradation but using specific technology for specific pesticides. However, in the middle of this time, cleaner techniques are essential for reducing pesticide contamination problems safely and environmentally friendly. As per the research findings, no single research finding provides concrete discussion on cleaner tactics for the remediation of contaminated sites. Therefore, in this review paper, we have critically discussed cleaner options for dealing with pesticide contamination problems as well as their advantages and disadvantages have also been reviewed. As evident from the literature, microbial remediation, phytoremediation, composting, and photocatalytic degradation methods are efficient and sustainable and can be used for treatment at a large scale in engineered systems and in situ. However, more study on the bio-integrated system is required which may be more effective than existing technologies.

Multiple Site Dissimilarities of Herbaceous Species Due to Coal Fly Ash Dumping Based Soil Heavy Metal Toxication.

The present study analyzes the determinants and patterns of the regional, local, and differential plant diversity of two different sites with similar climatic but varied edaphic factors. This research was undertaken to study the plant diversity and population structure as a consequence of variation in the soil quality between two biotopes: Guru Ghasidas Vishwavidyalaya in Koni (site-I) and National Thermal Power Corporation in Sipat (site-II). The soil of site-I was found to be fertile and showed rich vegetation. On the other hand, the soil of site II was found to be contaminated with heavy metals, which impacts the flora of the region. The ecology of both sites was studied, and their quantitative and qualitative aspects were compared and contrasted. The abundance, density, and richness of the plants in site II were fairly lower than in site-I, which was confirmed by utilizing Simpson's and Shannon's diversity indices. Many of the species collected from site II were heavy metal accumulators and could also serve as indicators of heavy metal toxicity.

An eco-sustainable approach towards heavy metals remediation by mangroves from the coastal environment: A critical review.

Mangroves provide various ecosystem services, carbon sequestration, biodiversity depository, and livelihoods. They are most abundant in marine and coastal ecosystems and are threatened by toxic contaminants like heavy metals released from various anthropogenic activities. However, they have significant potential to survive in salt-driven environments and accumulate various pollutants. The adverse effects of heavy metals have been extensively studied and recognized as toxic to mangrove species. This study sheds light on the dynamics of heavy metal levels, their absorption, accumulation and transport in the soil environment in a mangrove ecosystem. The article also focuses on the potential of mangrove species to remove heavy metals from marine and coastal environments. This review concludes that mangroves are potential candidates to clean up contaminated water, soil, and sediments through their phytoremediation ability. The accumulation of toxic heavy metals by mangroves is mainly through roots with limited upward translocation. Therefore, promoting the maintenance of biodiversity and stability in the coastal environment is recommended as an environmentally friendly and potentially cost-effective approach.

Deleterious Effect of Air Pollution on Human Microbial Community and Bacterial Flora: A Short Review.

A balanced microbiota composition is requisite for normal physiological functions of the human body. However, several environmental factors such as air pollutants may perturb the human microbiota composition. It is noticeable that currently around 99% of the world's population is breathing polluted air. Air pollution's debilitating health impacts have been studied scrupulously, including in the human gut microbiota. Nevertheless, air pollution's impact on other microbiotas of the human body is less understood so far. In the present review, the authors have summarized and discussed recent studies' outcomes related to air pollution-driven microbiotas' dysbiosis (including oral, nasal, respiratory, gut, skin, and thyroid microbiotas) and its potential multi-organ health risks.

Green synthesis of metalloid nanoparticles and its biological applications: A review.

Synthesis of metalloid nanoparticles using biological-based fabrication has become an efficient alternative surpassing the existing physical and chemical approaches because there is a need for developing safer, more reliable, cleaner, and more eco-friendly methods for their preparation. Over the last few years, the biosynthesis of metalloid nanoparticles using biological materials has received increased attention due to its pharmaceutical, biomedical, and environmental applications. Biosynthesis using bacterial, fungal, and plant agents has appeared as a faster developing domain in bio-based nanotechnology globally along with other biological entities, thus posing as an option for conventional physical as well as chemical methods. These agents can efficiently produce environment-friendly nanoparticles with the desired composition, morphology (shape as well as size), and stability, along with homogeneity. Besides this, metalloid nanoparticles possess various applications like antibacterial by damaging bacterial cell membranes, anticancer due to damaging tumour sites, targeted drug delivery, drug testing, and diagnostic roles. This review summarizes the various studies associated with the biosynthesis of metalloid particles, namely, tellurium, arsenic, silicon, boron, and antimony, along with their therapeutic, pharmaceutical and environmental applications.

Central Composite Designed Fast Dissolving Tablets for Improved Solubility of the Loaded Drug Ondansetron Hydrochloride.

Ondansetron tablets that are directly compressed using crospovidone and croscarmellose as a synthetic super disintegrant are the subject of this investigation. A central composite, response surface, randomly quadratic, nonblock (version 13.0.9.0) 32 factorial design is used to optimize the formulation (two-factor three-level). To make things even more complicated, nine different formulation batches (designated as F1-F9) were created. There were three levels of crospovidone and croscarmellose (+1, 0, -1). In addition to that, pre- and postcompressional parameters were evaluated, and all evaluated parameters were found to be within acceptable range. Among all postcompressional parameter dispersion and disintegration time, in vitro drug release experiments (to quantify the amount of medication released from the tablet) and their percentage prediction error were shown to have a significant influence on three dependent variables. Various pre- and postcompression characteristics of each active component were tested in vitro. Bulk density, tap density, angle of repose, Carr's index, and the Hausner ratio were all included in this analysis, as were many others. This tablet's hardness and friability were also assessed along with its dimension and weight variations. Additional stability studies may be conducted using the best batch of the product. For this study, we utilised the Design-Expert software to select the formulation F6, which had dispersion times of 17.67 ± 0.03 seconds, disintegration times of 120.12 ± 0.55 seconds, and percentage drug release measurements of 99.25 ± 0.36 within 30 minutes. Predicted values and experimental data had a strong correlation. Fast dissolving pills of ondansetron hydrochloride may be created by compressing the tablets directly.

Marine Alga Ulva fasciata-Derived Molecules for the Potential Treatment of SARS-CoV-2: An In Silico Approach.

SARS-CoV-2 is the causative agent of the COVID-19 pandemic. This in silico study aimed to elucidate therapeutic efficacies against SARS-CoV-2 of phyco-compounds from the seaweed, Ulva fasciata. Twelve phyco-compounds were isolated and toxicity was analyzed by VEGA QSAR. Five compounds were found to be nonmutagenic, noncarcinogenic and nontoxic. Moreover, antiviral activity was evaluated by PASS. Binding affinities of five of these therapeutic compounds were predicted to possess probable biological activity. Fifteen SARS-CoV-2 target proteins were analyzed by the AutoDock Vina program for molecular docking binding energy analysis and the 6Y84 protein was determined to possess optimal binding affinities. The Desmond program from Schrödinger's suite was used to study high performance molecular dynamic simulation properties for 3,7,11,15-Tetramethyl-2-hexadecen-1-ol-6Y84 for better drug evaluation. The ligand with 6Y84 had stronger binding affinities (-5.9 kcal/mol) over two standard drugs, Chloroquine (-5.6 kcal/mol) and Interferon α-2b (-3.8 kcal/mol). Swiss ADME calculated physicochemical/lipophilicity/water solubility/pharmacokinetic properties for 3,7,11,15-Tetramethyl-2-hexadecen-1-ol, showing that this therapeutic agent may be effective against SARS-CoV-2.

Effect of Fuel Preheating on Engine Characteristics of Waste Animal Fat-Oil Biodiesel in Compression Ignition Engine.

The present study aims at understanding the effects of fuel preheating on engine characteristics of waste animal fat-oil (WAF-O) biodiesel in a single-cylinder CI engine, with the preheating technique proposed as an effective means for enhancing the fuel properties. To understand the effects of the preheated fuel, the WAF-O biodiesel was preheated at 60, 80, 100 and 120 °C and tested along with neat diesel and unheated WAF-O biodiesel. For this purpose, biodiesel was produced from different animal wastes by means of KOH-assisted ethanol-based transesterification, reporting its maximum yield as 96.37 ± 1.8%, with significant distribution of unsaturated oleic acid, saturated palmitic acid and stearic acid. Upon evaluating its fuel characteristics as per ASTM D6751 standards, a rise in preheating temperature by 1 °C reduced the density and kinematic viscosity of WAF-O biodiesel by 0.383 kg/m3 and 0.025 mm2/s, respectively, and was explained by the weakening of intermolecular forces between its fatty acid ester molecules. Preheated samples reported superior combustion characteristics by exhibiting increased in-cylinder pressure (2.24%, on average) and heat release rates in addition to their shortened ignition delay (1−4 °CA). Furthermore, preheating of WAF-O biodiesel reduced its specific fuel consumption and increased its brake thermal efficiency by 7.86% (on average) and 9.23% (on average), respectively. However, higher preheating temperatures (>120 °C) resulted in increased fuel consumption owing to its varied flow characteristics. In addition to the changes in combustion characteristics, preheating WAF-O bio-diesel also resulted in reduced carbon monoxide, nitrous oxide and hydrocarbon emission by 13.88%, 7.21% and 26.94%, respectively, and increased carbon dioxide emission by 7.58%. Summing up, the enhancements in overall engine characteristics of preheated samples were accounted for by their improvised fuel injection characteristics due to their reduced density and viscosity, which ensured for their effective combustion.

Biologically Derived Gold Nanoparticles and Their Applications.

Nanotechnology is a rapidly evolving discipline as it has a wide variety of applications in several fields. They have been synthesized in a variety of ways. Traditional processes such as chemical and physical synthesis have limits, whether in the form of chemical contamination during synthesis operations or in subsequent applications and usage of more energy. Over the last decade, research has focused on establishing easy, nontoxic, clean, cost-effective, and environmentally friendly techniques for nanoparticle production. To achieve this goal, biological synthesis was created to close this gap. Biosynthesis of nanoparticles is a one-step process, and it is ecofriendly in nature. The metabolic activities of biological agents convert dissolved metal ions into nanometals. For biosynthesis of metal nanoparticles, various biological agents like plants, fungus, and bacteria are utilized. In this review paper, the aim is to provide a summary of contemporary research on the biosynthesis of gold nanoparticles and their applications in various domains have been discussed.

Emerging Trends in the Remediation of Persistent Organic Pollutants Using Nanomaterials and Related Processes: A Review.

Persistent organic pollutants (POPs) have become a major global concern due to their large amount of utilization every year and their calcitrant nature. Due to their continuous utilization and calcitrant nature, it has led to several environmental hazards. The conventional approaches are expensive, less efficient, laborious, time-consuming, and expensive. Therefore, here in this review the authors suggest the shortcomings of conventional techniques by using nanoparticles and nanotechnology. Nanotechnology has shown immense potential for the remediation of such POPs within a short period of time with high efficiency. The present review highlights the use of nanoremediation technologies for the removal of POPs with a special focus on nanocatalysis, nanofiltration, and nanoadsorption processes. Nanoparticles such as clays, zinc oxide, iron oxide, aluminum oxide, and their composites have been used widely for the efficient remediation of POPs. Moreover, filtrations such as nanofiltration and ultrafiltration have also shown interest in the remediation of POPs from wastewater. From several pieces of literature, it has been found that nano-based techniques have shown complete removal of POPs from wastewater in comparison to conventional methods, but the cost is one of the major issues when it comes to nano- and ultrafiltration. Future research in nano-based techniques for POP remediation will solve the cost issue and will make it one of the most widely accepted and available techniques. Nano-based processes provide a sustainable solution to the problem of POPs.