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Enzyme immobilization has emerged as a prodigious strategy in the enzymatic hydrolysis of lignocellulosic biomass (LCB) promising enhanced efficacy and stability of the enzymes. Further, enzyme immobilization on magnetic nanoparticles (MNPs) facilitates the easy recovery and reuse of biocatalysts. This results in the development of a nanobiocatalytic system, that serves as an eco-friendly and inexpensive LCB deconstruction approach. This review provides an overview of nanomaterials used for immobilization with special emphasis on the nanomaterial-enzyme interactions and strategies of immobilization. After the succinct outline of the immobilization procedures and supporting materials, a comprehensive assessment of the catalysis enabled by nanomaterial-immobilized biocatalysts for the conversion and degradation of lignocellulosic biomasses is provided by gathering state-of-the-art examples. The challenges and future directions associated with this technique providing a potential solution in the present article. Insight on the recent advancements in the process of nanomaterial-based immobilization for the hydrolysis of lignocellulosic biomass has also been highlighted in the article.
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Biomassa , Enzimas Imobilizadas , Lignina , Nanoestruturas , Lignina/química , Lignina/metabolismo , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Hidrólise , Nanoestruturas/química , BiocatáliseRESUMO
Industrialization and urbanization increased the use of chemicals in agriculture, vehicular emissions, etc., and spoiled all environmental sectors. It causes various problems among living beings at multiple levels and concentrations. Phytoremediation and microbial association are emerging as a potential method for removing heavy metals and other contaminants from soil. The treatment uses plant physiology and metabolism to remove or clean up various soil contaminants efficiently. In recent years, omics and artificial intelligence have been seen as powerful techniques for phytobial remediation. Recently, AI and modeling are used to analyze large data generated by omics technologies. Machine learning algorithms can be used to develop predictive models that can help guide the selection of the most appropriate plant and plant growth-promoting rhizobacteria combination that is most effective at remediation. In this review, emphasis is given to the phytoremediation techniques being explored worldwide in soil contamination.
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Inteligência Artificial , Biodegradação Ambiental , Poluentes do Solo , Metais Pesados , Plantas , Recuperação e Remediação Ambiental/métodosRESUMO
The present investigation focuses on assessing the water quality of groundwater surrounding brick kilns in the Jammu district of Jammu and Kashmir (J&K). At 43 different brick kiln sites in both north and south regions of Jammu, concentrations of heavy metals were measured using established techniques. The elements zinc, copper, iron, lead, cadmium, nickel, and manganese were analyzed utilizing an Atomic Absorption Spectrophotometer (AAS). The pollution load index value was consistently below unity across all sites, suggesting an absence of pollution and making the water suitable for consumption. The average concentrations, listed in ascending order, were found to be 0.38 mg/L for copper, 0.31 mg/L for zinc, 0.01 mg/L for iron, and 0.09 mg/L for manganese. Notably, concentrations of lead, cadmium, and nickel were found below the detectable levels. Evaluation of contamination factors revealed the sequence Cu > Fe > Zn > Mn, while the geo accumulation index followed the sequence Cu > Fe > Mn > Zn. Comparison of these findings with the established standards of World Health Organization and Bureau of Indian Standards indicated that the recorded ranges were within permissible limits. The study's outcomes suggest that heavy metal emissions from brick kilns may not significantly impact the quality of groundwater. Elevated copper levels found near brick kilns were likely to result from plumbing materials in the study area. Iron and manganese in groundwater seems to have geo-genic origin and not emission-related. This research represents a foundational step in examining groundwater contamination by heavy metals specifically in the neighborhood of brick kilns in Jammu district. It contributes to the establishment of a comprehensive database and serves as a reference point for future studies. Additionally, the study recommends regular monitoring of groundwater to ensure the maintenance of drinking water quality.
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In the present work, an investigation was performed based on the genera and species stated in Palmer pollution index to show the extent of organic pollution in the surface water of the Tawi watershed in the Jammu province of the Union Territory of Jammu and Kashmir using algal pollution indices. Sampling was carried out for two seasons, pre-monsoon (PRM) and post-monsoon (POM), at 16 locations distributed over the entire Tawi watershed. The physico-chemical variables like water temperature, pH, electrical conductivity, TDS, total alkalinity, total hardness, DO, BOD, COD, nitrate, and phosphate were analyzed. The seasonal distribution of the pollution-tolerant algal genera and species was recorded and the algal pollution index for both genus (AGP index) and species (ASP index) was also calculated. The concentration of BOD, COD, and nitrate in the sampled river water was found to be higher during the PRM season as compared to the POM season. The lower stretch of the watershed (Jammu Sub-Watershed) falls in class IV-V as per the polluted river stretch priority ranking based on BOD levels as BOD levels are >3 mg/L in the downstream locations during both seasons. A total of 23 algal taxa belonging to 8 families, Chlorophyceae (4 algal genera), Cyanophyceae (2 algal genera), Bacillariophyceae (7 algal genera), Zygnematophyceae (3 algal genera), Trebouxiophyceae (2 algal genera), Ulvophyceae (1 algal genus), Mediophyceae (1 algal genus), and Euglenophyceae (3 algal genera), have been reported in the Tawi watershed. The results of the Palmer indices showed a lack of organic pollution in the upstream, varying pollution levels in the midstream, and partially high to very high organic pollution levels in the downstream of the watershed. Comparative temporal analysis of the distribution of pollution-tolerant algal genera and species showed more organic pollution during PRM. Navicula and Cymbella were found to be the most abundant genera in almost all the stations, whereas Ulothrix, Cocconeis, Anacystis, and Crucigenia were the least recorded genera in the entire watershed. The results will enhance the understanding of the health status of the watershed, and provide database for watershed vulnerability assessment for sustainability and watershed management with spatio-temporal improvement.
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Clorófitas , Diatomáceas , Humanos , Qualidade da Água , Monitoramento Ambiental/métodos , Nitratos , Rios , Água Doce , Compostos Orgânicos , Estações do AnoRESUMO
Depleting fossil fuels and net carbon emissions associated with their burning have driven the need to find alternative energy sources. Biofuels are near-perfect candidates for alternative energy sources as they are renewable and account for no net CO2 emissions. However, biofuel production must overcome various challenges to compete with conventional fuels. Conventional methods for bioconversion of biomass to biofuel include chemical, thermochemical, and biological processes. Substrate selection and processing, low yield, and total cost of production are some of the main issues associated with biofuel generation. Recently, the uses of nanotechnology and nanoparticles have been explored to improve the biofuel production processes because of their high adsorption, high reactivity, and catalytic properties. The role of these nanoscale particles and nanocatalysts in biomass conversion and their effect on biofuel production processes and yield are discussed in the present article. The applicability of nanotechnology in production processes of biobutanol, bioethanol, biodiesel, biohydrogen, and biogas under biorefinery approach are presented. Different types of nanoparticles, and their function in the bioprocess, such as electron transfer, pretreatment, hydrolysis, microalgae cultivation, lipid extraction, dark and photo fermentation, immobilization, and suppression of inhibitory compounds, are also highlighted. Finally, the current and potential applications of nanotechnology in biorefineries are also discussed.
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Biological macromolecules have been significantly used in the medicine due to their certain therapeutic values. Macromolecules have been employed in medical filed in order to enhance, support, and substitute damaged tissues or any other biological function. In the past decade, the biomaterial field has developed considerably because of vast innovations in regenerative medicine, tissue engineering, etc. Different types of biological macromolecules such as natural protein and polysaccharide etc. and synthetic molecules such as metal based, polymer based, and ceramic based etc. have been discussed. These materials can be modified by coatings, fibres, machine parts, films, foams, and fabrics for utilization in biomedical products and other environmental applications. At present, the biological macromolecules can used in different areas like medicine, biology, physics, chemistry, tissue engineering, and materials science. These materials have been used to promote the healing of human tissues, medical implants, bio-sensors and drug delivery, etc. These materials also considered as environmentally sustainable as they are prepared in association with renewable natural resources and living organisms in contrast to non-renewable resources (petrochemicals). In addition, enhanced compatibility, durability and circular economy of biological materials make them highly attractive and innovative for current research.The present review paper summarizes a brief about biological macromolecules, their classification, methods of synthesis, and their role in biomedicine, dyes and herbal products.
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Materiais Biocompatíveis , Saúde Ambiental , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/classificação , Proteínas/química , Polissacarídeos/química , HumanosRESUMO
To address the challenge of heavy-metal ions in wastewater, boron nitride quantum dots (BNQDs) were synthesized in-situ on rice straw derived cellulose nanofibers (CNFs) as substrate. The composite system exhibited strong hydrophilic-hydrophobic interactions, as corroborated by FTIR, integrated the extraordinary fluorescence properties of BNQDs with fibrous-network of CNFs (BNQD@CNFs) yielding a surface of 35.147 m2 g-1 of luminescent fibers. Morphological studies revealed uniform distribution of BNQDs on CNFs due to hydrogen bonding, according high thermal stability with peak degradation occurring at 347.7 °C and quantum yield of 0.45. The nitrogen-rich surface of BNQD@CNFs exhibited strong affinity for Hg(II), quenching the fluorescence intensity due to combined inner-filter effect and photo-induced electron transfer. The limit of detection (LOD) and limit of quantification (LOQ) were 4.889 nM and 11.1 5 nM, respectively. BNQD@CNFs concomitantly exhibited adsorption of Hg(II) owing to strong electrostatic interactions, confirmed by X-ray photon spectroscopy. Presence of polar BN bonds favoured 96 % removal of Hg(II) at 10 mg L-1 with maximum adsorption capacity of 314.5 mg/ g. Parametric studies corresponded to pseudo-second order kinetics and Langmuir isotherm with R2 ≈ 0.99. BNQD@CNFs exhibited recovery rate between 101.3 %-111 % for real water samples and recyclability upto 5 cycles, demonstrating high potential in wastewater remediation.
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Mercúrio , Nanofibras , Pontos Quânticos , Poluentes Químicos da Água , Celulose/química , Águas Residuárias , Nanofibras/química , Pontos Quânticos/química , Mercúrio/análise , Íons , Adsorção , Poluentes Químicos da Água/química , CinéticaRESUMO
An easily recyclable biocatalyst (Lac@CDI-MCNFs) was synthesized by immobilizing laccase on rice straw-derived carbonyldiimidazole mediated magnetized cellulose nanofibers (MCNFs). Lac@CDI-MCNFs were utilized for bioremediation of cefixime antibiotic (CT), carbofuran pesticide (CF) and safranin O dye (SO) via oxidation-reduction reactions in wastewater. MCNFs provided enhanced pH, temperature and storage stability to laccase and allowed reusability for up to 25 cycles with mere 20 % decline in efficacy. The Lac@CDI-MCNFs effectively degraded 98.2 % CT and 96.8 % CF into benign metabolites within 20 h and completely degraded SO in just 7 h. Response surface modelling (RSM) was employed based on the Box Behnken Design to evaluate the effect of various parameters i.e. pH, catalyst dosage and the pollutants concentration which was further validated with experimental studies. The degradation products were identified using LCMS, which allowed the degradation pathway of the pollutants to be determined. The degradation of all pollutants followed first- order kinetics with rate constants of 0.1775, 0.0832 and 0.958 h-1 and half-life of 3.9, 5.0 and 0.723 h for CT, CF and SO, respectively. Lac@CDI-MCNFs was demonstrated to be an effective catalyst for the degradation of multifarious pollutants.
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Poluentes Ambientais , Nanofibras , Biodegradação Ambiental , Celulose , Enzimas Imobilizadas/metabolismo , Lacase/metabolismoRESUMO
In the present laboratory scale experiment, we report the fabrication of chlorophyll sensitized (BiO)2CO3/CdWO4/rGO (BCR) photo-catalyst. The green approach has been adopted for boosting the optical activity by chlorophyll as a sensitizer. The functionality, nature and surface compositions of synthesized photo-catalyst have been identified by FTIR, XRD and XPS instrumentation. The internal and surface morphology has been studied using FE-SEM and HR-TEM. The optical activity has been investigated by UV-vis and photoluminescence spectroscopy. The catalytic activity of chlorophyll sensitized BCR have been tested for the photo degradation of Chlorzoxazone (CZX) under simulated visible light for 90 min. The detailed comparison has been studied for the different loading amount of chlorophyll and RGO onto BCR photo-catalyst. The potential of BCR for the photo-degradation of CZX was investigated under various operational parameters such as catalysts dosage, pollutant concentration, effect of pH and ions etc. Approximately, 96.2% of CZX has been degraded over 90 min with the optimum catalyst amount 250 mgL-1 at pH 7. The âOH radical has been identified as major reactive species using radical scavenging experiment. The mineralization of CZX has been evaluated in terms of HR-MS and TOC-COD analysis.
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Clorzoxazona , Grafite , Catálise , Clorofila , Grafite/químicaRESUMO
Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particularly in the Jammu city is experiencing pollution load and the quality is degraded. The present study highlights the impact of COVID-19 lockdown on the water quality of Tawi river in Jammu, J&K Union Territory. Water quality data based upon the real-time water monitoring for four locations (Below Tawi Bridge, Bhagwati Nagar, Belicharana and Surajpur) have been obtained from the web link of Jammu and Kashmir Pollution Control Board. The important parameters used in the present study include pH, alkalinity, hardness, conductivity, BOD and COD. The river was designated fit for bathing in all the monitoring locations except Bhagwati Nagar which recorded a BOD value >5 mg/L because of domestic sewage and municipal waste dumping. The overall water quality in the river during lockdown was good and falls in Class B with pH (7.0-8.5), alkalinity (23.25-185.0 mg/L), hardness (84.25-177.5 mg/L), conductivity (117-268 ms/cm). The improved water quality obtained during lockdown is never long-lasting as evident from the BOD and COD values observed during Unlock 1.0 due to accelerated anthropogenic activities in response to overcoming the economic loss, bringing the river water quality back to the degraded state. The statistical analysis known as cluster analysis has also been performed to evaluate the homogeneity of various monitoring sites based on the physicochemical variables. The need of the hour is to address the gaps of rejuvenation strategies and work over them for effective river resiliency and for sustainable river basin management.
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The outbreak of COVID-19 pandemic has created havoc all across the globe causing exponential casualties and tremendous health and economic loss. With increasing COVID-19 cases, the amount of biomedical waste has increased manifolds making more people vulnerable to the pandemic. The developing and underdeveloped countries are already facing the challenges of waste management, and the waste generated during the pandemic scenario has added to the already existing challenges. The improper waste management practices need to be corrected; otherwise, the world will be facing a new disaster that could be termed as 'waste disaster'. The increase in COVID-19-associated waste (CAW) quantity and their availability in the environment will result in their easy approach to other organisms, which will possibly increase the potential risk of food chain contamination. Some of the countries have already started to make backup plans and are struggling to overcome the 'waste disaster'. In light of the limited knowledge available on the mutational properties and possible hosts of this newly emerged COVID-19, there is a great demand to have an efficient strategy to prevent the environment from further contamination in India. The necessity of the prevailing time is to create a more efficient, automatic, mechanized, and well-modified waste management system for handling the present situation and delaying the projected waste disaster in the near future in the era of COVID-19. The article aims to address the issues that originated from waste discharges, their potential sources along with possible sustainable solutions.
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COVID-19 , Gerenciamento de Resíduos , Países em Desenvolvimento , Humanos , Pandemias , SARS-CoV-2RESUMO
In present study, a simple, effective and rapid green method using leaf extract of Melia azedarach was explored for the synthesis of Cu-ZnO nano heterojunction particles. The leaf extract of Melia azedarach acts as a reducing agent and prevents the agglomeration of nanoparticles. Different standard analytical techniques were used to study the morphology and size of synthesized nanocomposite. The efficiency of the synthesized material was tested as a photocatalyst for the degradation of simulated wastewater having chlorpyriphos pesticide. The different factors have been investigated such as pH of the solution, catalyst dosage and conact time. Approximately, 81% of chlorpyrifos was degraded after 240 min of solar illumination. The generation of hydroxyl radicals at the catalysts surface owing to photo-irradiation contributed to the chlorpyrifos degradation. The maximum photo-degradation (91%) of pesticides was observed at 6.0 pH. The pathway for the degradation of chlorpyriphos has been checked by LC-MS and this hinting the absence of any harmfull side product. The COD removal and TOC was found to be 32.4% and 28.5%, respectively. The photodegradation of chlorpyriphos using Cu-ZnO nanocomposite was followed the pseudo-first-order kinetic with higher value of regressiuon coefficient (0.99).
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Clorpirifos , Nanocompostos , Óxido de Zinco , Catálise , IluminaçãoRESUMO
In the current scenario, alternative energy sources are the need of the hour. Organic wastes having a larger fraction of biodegradable constituents present a sustainable bioenergy source. It has been reported that the calorific value of biogas generated by anaerobic digestion (AD) is 21-25 MJ/m3 with the treatment which makes it an excellent replacement of natural gas and fossil fuels and can reduce more than 80% greenhouse gas emission to the surroundings. However, there are some limitations associated with the AD process for instance ammonia build-up at the first stage reduces the rate of hydrolysis of biomass, whereas, in the last stage it interferes with methane formation. Owing to special physicochemical properties such as high activity, high reactive surface area, and high specificity, tailor-made conductive nanoparticles can improve the performance of the AD process. In the AD process, H2 is used as an electron carrier, referred as mediated interspecies electron transfer (MIET). Due to the diffusion limitation of these electron carriers, the MIET efficiency is relatively low that limits the methanogenesis. Direct interspecies electron transfer (DIET), which enables direct cell-to-cell electron transport between bacteria and methanogen, has been considered an alternative efficient approach to MIET that creates metabolically favorable conditions and results in faster conversion of organic acids and alcohols into methane. This paper discusses in detail the application of conductive nanoparticles to enhance the AD process efficiency. Interaction between microbes in anaerobic conditions for electron transfer with the help of CNPs is discussed. Application of a variety of conductive nanomaterials as an additive is discussed with their potential biogas production and treatment enhancement in the anaerobic digestion process.
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Reatores Biológicos , Nanopartículas , Anaerobiose , Transporte de Elétrons , MetanoRESUMO
While the wound healing activity of thymoquinone (TQ) is well known, its clinical effectiveness remains limited due to the inherently low aqueous solubility, resulting in suboptimal TQ exposure in the wound sites. To address these problems, TQ loaded chitosan-lecithin micelles for wound healing were prepared and its efficacy was determined in vivo in the excision wound model. Firstly, the co-block polymer of chitosan and soya lecithin was synthesized which has low critical micelle concentration (CMC). Its employment in the development of TQ loaded polymeric micelles by Self-assembly method resulted in the stable polymeric micelle composition having requisite small particle size (<100â¯nm), narrow size distribution (close to zero) and high entrapment efficiency (98.77 %) of TQ. The designed nano-carriers not only substantially entrapped the drug but also controlled the release rate of TQ. The TQ-polymeric micelle hydrogel exhibited superior wound healing efficacy to the native TQ and Silver Sulphadiazine.
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Benzoquinonas/administração & dosagem , Quitosana/farmacologia , Portadores de Fármacos/uso terapêutico , Descoberta de Drogas , Lecitinas/farmacologia , Nanofibras/uso terapêutico , Animais , Quitosana/química , Liberação Controlada de Fármacos , Lecitinas/química , Camundongos Endogâmicos BALB C , Micelas , Tamanho da Partícula , Cicatrização/efeitos dos fármacosRESUMO
Nanohydrogel of tragacanth gum using microwave radiations is used for the controlled release of ampicillin. Tragacanth gum was grafted with itaconic acid, employing graft copolymerization in the presence of N, N1-methylene-bis-acrylamide (MBA) as cross linker, and potassium persulphate as initiator. The prepared nanohydrogel was characterized using FTIR, XRD, SEM, and TEM. Besides, the hydrogel was evaluated for in vitro drug release in distilled water and different pH values, and antimicrobial efficacy against E. Coli by well diffusion assay. In vitro drug release studies, at different pH values (2.2, 5.4 and 9.4), and distilled water, pH 2.2 was considered as the optimized pH for maximum drug release. Finally, through antimicrobial efficacy studies against E. Coli, it was observed that ampicillin loaded nanohydrogel, was more efficient in comparison to that of plain ampicillin drug.
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Ampicilina/química , Portadores de Fármacos/química , Hidrogéis/química , Nanoestruturas/química , Gomas Vegetais/química , Succinatos/química , Tragacanto/química , Ampicilina/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Preparações de Ação Retardada , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Cinética , Micro-Ondas , TemperaturaRESUMO
The present study was attempted to ascertain the possible application of activated carbon as a cost-effective and eco-friendly adsorbent prepared via microwave-assisted chemical activation. The activated carbon was characterized using different techniques. The various adsorption parameters have been optimized to examine the viability of activated carbon as a plausible sorbent for the remediation of Congo red (CR) dye from the aquatic system. The equilibrium data adequately fitted to the Langmuir isotherm with better R2 (0.994). The maximum adsorption capacity (qm) of activated carbon was recorded to be 68.96â mg/g. Additionally, sorptional kinetic data were examined by reaction-based and diffusion-based models such as pseudo-first-order and pseudo-second-order equations, and Elovich, intra-particle diffusion, and Dumwald-Wagner models, respectively. The computed values of thermodynamic parameters such as free energy change (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were recorded as -3.63, 42.47 and 152.07â J/mol K, respectively, at 30°C, which accounted for a favorable, spontaneous and endothermic process. The regeneration study emphasized that the percentage uptake declined from 90.35% to 83.45% after six cycles of testing. So, our findings implied that activated carbon produced from biomass must be cost-effectively used as an adsorbent for detoxifying the CR dye from industrial effluents.
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Carvão Vegetal , Micro-Ondas , Adsorção , Difusão , Concentração de Íons de Hidrogênio , Cinética , Termodinâmica , Poluentes Químicos da Água , Purificação da ÁguaRESUMO
Tragacanth gum-cl-poly (lactic acid-co-itaconic acid) (TG-cl-p(LA-co-IA)) hydrogel is synthesized through graft copolymerization reaction using microwave assisted technique. The synthesized hydrogel was characterised using various analytical and characterization techniques such as FTIR, FESEM, XRD, TGA, TEM and SEM. It was observed that, the maximum percentage swelling (Ps) of the hydrogel was 311.61% after 6h at room temperature and 298.06% after 3h at 60°C and TG-cl-p(LA-co-IA) exhibited highest Amoxicillin loading (73%) in double distilled waterafter 24h. From the controlled release studies, it was evident that maximum drug release of about 96% took place at pH 2.2=after 6h. The synthesized hydrogel also showed mild antioxidant properties and 43.85% of free radical scavenging was occurred at a concentration of 640µg/mL and hence it can be effectively used to reduce the oxidative stresses. In addition to this, the antibacterial studies also showed that it is more effective against S. aureus.
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Antioxidantes/farmacologia , Sistemas de Liberação de Medicamentos , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Ácido Láctico/farmacologia , Gomas Vegetais/farmacologia , Succinatos/farmacologia , Tragacanto/química , Antibacterianos/farmacologia , Reagentes de Ligações Cruzadas/química , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Micro-Ondas , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Fatores de Tempo , Difração de Raios XRESUMO
In the present study, gelatin-Zr(IV) phosphate nanocomposite (GT/ZPNC) was synthesized by sol-gel method by mixing the gelatin gel into the inorganic part Zr (IV) phosphate (ZP). The GT/ZPNC was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM), transmission electron micron scope (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The photodegradation activity of GT/ZPNC was explored for the removal of methylene blue (MB) and fast green (FG) dyes from aqueous solution. It was found that 87.81% MB and 89.91% FG were degraded within five hours. Also, the kinetics of photocatalytic degradation for MB and FG was investigated via pseudo first-order kinetic model with higher regression coefficient values (R2). The antimicrobial efficiency of GT/ZPNC was investigated against E. coli.
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Anti-Infecciosos/química , Gelatina/química , Nanocompostos/química , Nanotecnologia/métodos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Fotólise , TermogravimetriaRESUMO
In this paper, microwave assisted preparation of carboxymethyl cellulose-cl-poly(lactic acid-co-itaconic acid) (CMC-cl-P(LA-co-IA)) hydrogel was reported via facile graft copolymerization using N,N1-methylene-bis-acrylamide (MBA) and potassium persulphate as cross linker and initiator. Different reaction parameters were optimized to achieve good yield. The formation of hydrogel was confirmed by characterization techniques such as Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, thermo gravimetric analysis, transmission electron microscopy etc. The antimicrobial activities of the hydrogel were studied against Staphylococcus aureus and Escherichia coli. About 95% killing of bacteria was recorded after 24h. The controlled release of amoxicillin drug from hydrogel was evaluated as a function of pH and time. Maximum drug release of 98% was recorded at 2.2 pH after 7h. The kinetic studies showed non-Fickian diffusion of the drug.
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Amoxicilina/química , Antibacterianos/química , Carboximetilcelulose Sódica/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Ácido Láctico/química , Polímeros/química , Succinatos/química , Amoxicilina/farmacologia , Preparações de Ação Retardada , Portadores de Fármacos/química , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Polimerização , Staphylococcus aureus/efeitos dos fármacos , TemperaturaRESUMO
Trimetallic nanoparticles are mainly formed by the combination of three different metals. The trimetallic catalysts were considerably more professional than bimetallic one. The trimetallic and bimetallic nanoparticles are of enormous attention than that of monometallic in both technological and scientific view as in these nanoparticles the catalytic properties can be tailored better than that of in the single monometallic catalyst. The trimetallic nanoparticles have been synthesized by different methods such as microwave, selective catalytic reduction, micro-emulsion, co-precipitation and hydrothermal etc. The surfaces area of trimetallic nanoparticles is comparatively unstable and thus gets simply precipitated away from their solution and ultimately resulted in their reduced catalytic activity. By using stabilizers like block copolymers, organic ligands, surfactants and dendrimers the trimetallic nanoparticles can be stabilized. The nanocomposites of trimetallics have been synthesized with inorganic and organic compounds such as: carbon, graphene, gelatin, cellulose, starch, chitosan, alginate, collagen and Al2O3 etc. Trimetallic nanoparticles are used as a catalyst due to their outstanding electrochemical catalytic activity in comparison with the monometallic or bimetallic nanoparticles.