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1.
Int J Biol Macromol ; 278(Pt 3): 135007, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39181355

RESUMEN

Present research work reports the synthesis of Gellan gum (Gg) and methacrylic acid (MA) based grafted hydrogels (Gg-cl-poly(MA)) crosslinked using N, N'- methylene-bis-acrylamide (MBA) and the evaluation of their efficiency to be used as a sustained drug delivery carrier for anticancer drug i.e., etoposide. Various characterization techniques like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) confirmed the grafting of Gg with MA and the formation of crosslinked Gg-cl-poly(MA) hydrogel polymer. The synthesized hydrogel showed pH-dependent swelling properties and exhibited a maximum swelling capacity of 867 % under optimized environmental conditions. The Gg-cl-poly(MA) was biocompatible and non-cytotoxic, which was confirmed by the hemolytic and cytotoxic tests. The release dynamics of etoposide from the Gg-cl-poly(MA) polymer matrix was checked under specific physiological conditions. Drug release was found to be significantly higher in the acidic medium, followed by the neutral and alkaline medium. This clearly indicated that etoposide drug release through synthesized hydrogel was stomach-specific and it is effective for the treatment of stomach cancer. The release mechanism of the etoposide drug was a Fickian-type diffusion mechanism in the acidic medium and a non-Fickian-type diffusion mechanism in the neutral and alkaline medium. The release profile of the etoposide was best fitted to the first-order rate model. The results showed that the synthesized hydrogel (i.e., Gg-cl-poly(MA)) was biocompatible, non-toxic, and could be used for the treatment of stomach cancer.


Asunto(s)
Antineoplásicos , Portadores de Fármacos , Liberación de Fármacos , Etopósido , Hidrogeles , Polisacáridos Bacterianos , Etopósido/química , Hidrogeles/química , Hidrogeles/síntesis química , Polisacáridos Bacterianos/química , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/administración & dosificación , Portadores de Fármacos/química , Portadores de Fármacos/síntesis química , Humanos , Concentración de Iones de Hidrógeno , Sistemas de Liberación de Medicamentos , Espectroscopía Infrarroja por Transformada de Fourier
2.
PLoS One ; 19(6): e0303313, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38857300

RESUMEN

Cloud data centers present a challenge to environmental sustainability because of their significant energy consumption. Additionally, performance degradation resulting from energy management solutions, such as virtual machine (VM) consolidation, impacts service level agreements (SLAs) between cloud service providers and users. Thus, to achieve a balance between efficient energy consumption and avoiding SLA violations, we propose a novel VM consolidation algorithm. Conventional algorithms result in unnecessary migrations when improperly selecting VMs. Therefore, our proposed E2SVM algorithm addresses this issue by selecting VMs with high load fluctuations and minimal resource usage from overloaded servers. These selected VMs are then placed on normally loaded servers, considering their stability index. Moreover, our approach prevents server underutilization by either applying all or no VM migrations. Simulation results demonstrate a 12.9% decrease in maximum energy consumption compared with the minimum migration time VM selection policy. In addition, a 47% reduction in SLA violations was observed when using the medium absolute deviation as the overload detection policy. Therefore, this approach holds promise for real-world data centers because it minimizes energy waste and maintains low SLA violations.


Asunto(s)
Algoritmos , Nube Computacional , Electricidad
3.
RSC Adv ; 13(12): 8409-8419, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36926004

RESUMEN

The present work describes the synthesis of a cellulose and gelatin based hydrogel by the grafting of poly(acrylic acid) using ammonium persulphate (APS)-glutaraldehyde as the initiator-crosslinker system. The structure of the hydrogel was studied through scanning electron microscopy (SEM) and FTIR. The maximum swelling rate of C-G-g-poly(AA) was found to be 92 g g-1 at pH 10. The size and structure of the prepared silver nanoparticles (AgNPs) were studied through TEM and zeta potential, and it was found that the synthesized AgNPs were spherical and the size range was 11-30 nm. The reduction process followed pseudo 1st order kinetics. EtBr and eosin dye degradation were more than 4 times faster, when AgNPs were used with sodium borohydride. Thus, it can be concluded that the synthesized C-G-g-poly(AA) AgNPs hybrid hydrogel is effective for the reduction and degradation of carcinogenic dyes in wastewater.

4.
Biosensors (Basel) ; 13(2)2023 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-36831968

RESUMEN

With the move of molecular tests from diagnostic labs to on-site testing becoming more common, there is a sudden rise in demand for nucleic acid-based diagnostic tools that are selective, sensitive, flexible to terrain changes, and cost-effective to assist in point-of-care systems for large-scale screening and to be used in remote locations in cases of outbreaks and pandemics. CRISPR-based biosensors comprise a promising new approach to nucleic acid detection, which uses Cas effector proteins (Cas9, Cas12, and Cas13) as extremely specialized identification components that may be used in conjunction with a variety of readout approaches (such as fluorescence, colorimetry, potentiometry, lateral flow assay, etc.) for onsite analysis. In this review, we cover some technical aspects of integrating the CRISPR Cas system with traditional biosensing readout methods and amplification technologies such as polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and recombinase polymerase amplification (RPA) and continue to elaborate on the prospects of the developed biosensor in the detection of some major viral and bacterial diseases. Within the scope of this article, we also discuss the recent COVID pandemic and the numerous CRISPR biosensors that have undergone development since its advent. Finally, we discuss some challenges and future prospects of CRISPR Cas systems in point-of-care testing.


Asunto(s)
Técnicas Biosensibles , COVID-19 , Ácidos Nucleicos , Humanos , Sistemas de Atención de Punto , Pruebas en el Punto de Atención , Bioensayo , Técnicas de Amplificación de Ácido Nucleico , Prueba de COVID-19
5.
Luminescence ; 38(7): 1011-1025, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36042553

RESUMEN

Due to their capacity to immobilize more bioreceptor parts at reduced volumes, nanomaterials have emerged as potential tools for increasing the sensitivity to specific molecules. Furthermore, carbon nanotubes, gold nanoparticles, polymer nanoparticles, semiconductor quantum dots, nanodiamonds, and graphene are among the nanomaterials that are under investigation. Due to the fast development of this field of research, this review summarizes the classification of biosensors using the main receptors and design of biosensors. Numerous studies have concentrated on the manipulation of persistent luminescence nanoparticles (PLNPs) in biosensing, cell tracking, bioimaging, and cancer therapy due to the effective removal of autofluorescence interference from tissues and the ultra-long near-infrared afterglow emission. As luminescence has a unique optical property, it can be detected without constant external illumination, preventing autofluorescence and light dispersion through tissues. These successes have sparked an increasing interest in creating novel PLNP types with the desired superior properties and multiple applications. In this review, we emphasize the most recent developments in biosensing, imaging, and image-guided therapy whilst summarizing the research on synthesis methods, bioapplications, biomembrane modification, and the biosafety of PLNPs. Finally, the remaining issues and difficulties are examined together with prospective future developments in the biomedical application field.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Nanopartículas , Nanoestructuras , Nanotubos de Carbono , Luminiscencia , Oro , Técnicas Biosensibles/métodos
6.
Heliyon ; 8(8): e10363, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36082336

RESUMEN

The interfacial along with bulk characteristics of the aqueous solutions of ILs with dissimilar cationic head group viz. 1-dodecyl-3-methylimidazolium bromide ([C12mim][Br]), and N-dodecyl-N-methylmorpholinium bromide ([Mor1,12][Br]) in the absence and the presence of an amino acid L-Methionine as an external additive have been examined by electrical conductivity, UV-Visible, surface tension, and DLS measurements. The CMC values, and the lowest maximum surface excess concentration (Гmax) achieved from all three techniques, and surface tension measurements respectively displayed more surface activity of the [C12mim][Br] than the [Mor1,12][Br]. Also, the morpholinium head group is less hazardous than imidazolium, it can be utilised to design ILs that are greener, mainly in combination with polar, small, and non-toxic side chains and anions.

7.
Polymers (Basel) ; 14(9)2022 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-35567081

RESUMEN

The present research work intended to demonstrate the green synthesis of silver nanoparticles (AgNPs) using the plant extract Saccharum officinarum, and then the development of chitosan-silver (CH-Ag) bionanocomposite. The synthesized AgNPs were characterized using UV spectroscopy, Fourier transform infrared (FTIR), and transmission electron microscopy (TEM). The maximum absorption spectrum peak was observed at 420 nm, revealing the formation of AgNPs by the stem extract of S. officinarum. The AgNPs sizes were in the range of 10-50 nm. Itraconazole is an antifungal that is used as a novel drug to study its release through synthesized bionanocomposite. Different kinetic models, such as zero order, first order, Korsmeyer-Peppas, Hixson-Crowell and Higuchi, were used to study the drug release profile from the synthesized CH-Ag bionanocomposite. The first-order kinetic model showed the best fit for the drug release with the maximum regression coefficient value. The antibacterial activity of the synthesized CH-Ag bionanocomposite was examined against Bacillus cereus, Staphylococcus, and Escherichia coli, and it was shown to be efficient against these strains.

8.
Front Chem ; 10: 959104, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36688053

RESUMEN

The present study aimed to synthesize gum katira-silver nanoparticle-based bionanocomposite. Different characterization techniques were used to analyze the synthesized bionanocomposite, such as Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), thermo-gravimetric analysis (TGA), and transmission electronic microscopy (TEM). AgNPs were formed and were 6-20 nm in size. Thermo-gravimetric analysis showed that synthesized nanocomposites are more thermally stable than gum katira. All the reaction conditions, such as time, temperature, pH, solvent, amount of nanoparticles, the concentration of the initiator, crosslinker, and monomer were optimized with respect to swelling. The results showed that the highest percentage swelling (Ps) of Gk-cl-poly(AA) was 796%, and 867% of AgNPs were imbibed by Gk-cl-poly(acrylic acid)-AgNPs. Synthesized bionanocomposite was used as an adsorbent material for the adsorption of methyl red (MR) dye. The effects of different reaction conditions were also optimized to attain maximum adsorption of MR dye. The maximum dye adsorption through Gk-cl-poly(AA)-AgNPs bionanocomposite was 95.7%. Diverse kinetic and isotherm models were used to study the adsorption data. The R 2 value was established as 0.987 and k2 was .02671. The greater R 2 value of second-order kinetics over first-order kinetics suggested that MR adsorption by nanocomposite is best explained by pseudo-second-order kinetics, indicating that dye adsorption occurred through chemisorption. The R 2 value was determined to be .9954. The correlation coefficient values of Gk-cl-poly(AA)-AgNPs were best fitted by the Freundlich adsorption isotherm. Overall, synthesized bionanocomposite is a proficient material for removing of MR dye from wastewater.

9.
Arch Environ Contam Toxicol ; 81(2): 272-284, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34272567

RESUMEN

Soil, a connecting link between biotic and abiotic components of terrestrial ecosystem, receives different kinds of pollutants through various point and nonpoint sources. Among different sources of soil pollution, contaminated irrigation water is one of the most prominent sources affecting soils throughout the globe. The irrigation water (both surface and groundwater) is increasingly getting polluted with contaminants such as metal(loid)s due to various anthropogenic activities. The present study was conducted to analyze metal(loid) contents in agricultural soil samples (N = 24) collected from fields along the banks of rivers Beas and Sutlej flowing through Punjab state of India, using wavelength-dispersive X-ray fluorescence (WDXRF) spectroscopy. The soil samples were also analyzed for their genotoxic potential using Allium cepa root chromosomal aberration assay. The rivers Beas and Sutlej are contaminated with municipal and industrial effluents in different parts of Punjab. The soil samples analyzed were found to have higher contents of arsenic, cobalt and chromium in comparison with the reference values given by various international agencies. Pollution assessment using different indices like index of geo-accumulation, enrichment factor and contamination factor revealed that the soil samples were highly polluted with cobalt and arsenic. The Allium cepa assay revealed that maximum genotoxicity was found in soil samples having higher contents of As and Co. Pearson's correlation analysis revealed strong positive correlation between the different metal(loid)s which indicated common sources of these metal(loid)s. Therefore, efforts must be taken to reduce the levels of these metal(loid)s in these agricultural soils.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Daño del ADN , Ecosistema , Monitoreo del Ambiente , Metales Pesados/análisis , Metales Pesados/toxicidad , Suelo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad
10.
J Environ Health Sci Eng ; 18(2): 1175-1187, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33312633

RESUMEN

The present work seeks to investigate the kinetics and thermodynamic studies of ethidium bromide (EtBr) and eosin adsorption onto the synthesized Manganese (II) doped Zinc (II) Sulphide nanoparticles. A convenient scheme of co-precipitation was used for the synthesis of Manganese (II) doped Zinc (II) Sulphide nanoparticles. The Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and X-ray diffractogram (XRD) techniques were used for the characterization of synthesized nanoparticles. The adsorption study was undertaken in a systematic manner. Effects of different experimental parameters were studied using batch adsorption method. It was evident from the results that EtBr and eosin removal was inversely proportional to the concentration of initial dye and directly proportional to contact time and adsorbent used. To study the adsorption equilibrium three different isotherm models like Langmuir, Freundlich and Flory-Huggins were used. It was observed that adsorption data synced most successfully with Langmuir isotherm model as compared to Freundlich and Flory-Huggins isotherm model. To fit the investigational statistics, the kinetic models pseudo 1st order, pseudo 2nd order and intra particle diffusion were taken onto consideration. The maximum dye removal of 98.19% and 97.16% for EtBr and eosin, was observed during the synthesis of nanoparticles.

11.
Environ Sci Pollut Res Int ; 27(14): 17032-17042, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32146668

RESUMEN

Metal(loid) contamination of vital food grains such as wheat and rice is a very serious problem throughout the world because consumption of such contaminated food can lead to severe health effects in humans. Metal(loid) contamination of food crops can occur from different sources such as contaminated soil, irrigation water, and aerial deposition. Therefore, the present study was conducted to analyze potential non-carcinogenic and carcinogenic health impacts posed by different metal(loid)s (As Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, and Zn) via consumption of wheat and rice grown on metal(loid)-contaminated soils in areas around rivers (Beas and Sutlej) of Punjab, India. Among the metal(loid)s analyzed in wheat and rice samples, contents of As, Cd, Cr, Ni, and Pb were found to be above the international (FAO/WHO and EU) maximum permissible limits. The non-carcinogenic and carcinogenic health risk assessment of individual metal(loid)s revealed that As posed highest risk followed by Cd, Cu, Fe, Mn, and Pb. The values of indices calculated for analysis of combined non-carcinogenic, i.e., (hazard index; range 3.49-15.94) and carcinogenic (total carcinogenic risk index; range 8.30 × 10-4-131.62 × 10-4) risks for both crops were found to be many fold higher than the prescribed limits of 1.0 and 1.0 × 10-4, respectively. Thus, the analysis of combined risks posed by metal(loid)s indicated that human population consuming wheat and rice from the study area faced both non-carcinogenic and carcinogenic health risks. Therefore, immediate steps must be taken to reduce the levels of metal(loid)s in wheat and rice from the study area.


Asunto(s)
Metales Pesados/análisis , Contaminantes del Suelo/análisis , China , Monitoreo del Ambiente , Contaminación Ambiental/análisis , Humanos , India , Medición de Riesgo , Suelo
12.
J Environ Health Sci Eng ; 17(1): 367-376, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31322630

RESUMEN

The present study deals with the green approach for the biosynthesis of copper oxide-Aloe vera (CuO-A) based nanoparticles using leaf extract of Aloe barbadensis miller. Synthesized nanoparticles were characterized through different techniques like TEM and FTIR. As the size decreases and surface area increases, these are prominently used as a very good adsorbent. The effects of different parameters like adsorbent dosage, pH, contact time, initial dye concentration and temperature are optimised to get the maximum removal of methylene blue dye from the solution. The maximum dye removal was found to be 98.89% with initial concentration of 100 mg/L at alkaline pH in 210 min., with shaking speed of 150 rpm. The Langmuir result reveals a better consistency than the Freundlich model with 95.5 mg/g. Lagergren's model was used to study the kinetics of the system. Mechanistic behaviour was study through intra-particle diffusion study and Boyd plot. Thermodynamic study showed spontaneous and endothermic nature of the adsorption. Furthermore, synthesized CuO-A nanoparticles showed good antibacterial activity against different strains of bacteria. The zone of inhibition was found to be 11 mm, 12 mm, 8 mm and 9 mm in Pseudomonas, Klebsiella, Staphylococcus and E.coli, respectively.

13.
Int J Biol Macromol ; 132: 1252-1261, 2019 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-30954596

RESUMEN

This work reports the synthesis of lipase enzyme catalyzed biodegradable hydrogel interpenetrating polymer network (hydrogel-IPN) of natural gum polysaccharide i.e. gum tragacanth (GT) with acrylamide (AAm) and methacrylic acid (MAA) and their potential application in the delivery of agrochemicals. Biodegradation experiments were performed using composting and soil burial methods of biodegradation. Complete degradation of synthesized hydrogel-IPN occurred within 77 days using composting method, while using soil burial method 81.26% degradation occurred after 77 days. Furthermore, effect hydrogel-IPN degradation on the fertility of soil was also studied through macro-analysis of soil. Water retention capacity of clay soil and sandy loam soil was improved after mixing swelled sample of hydrogel-IPN with these soil samples. The potential of hydrogel-IPN was also tested for sustained and slow release of two agrochemicals i.e. urea and calcium nitrate. Kinetics of agrochemicals release revealed that the release rate of both the fertilizers was initially higher which kept on decreasing with time. Diffusion mechanism of agrochemicals followed Case-II diffusion type behavior. Therefore, synthesized hydrogel-IPN is important from agriculture view point and can be used for sustained and controlled release of agrochemicals.


Asunto(s)
Agroquímicos/química , Hidrogeles/química , Gomas de Plantas/química , Polisacáridos/química , Suelo/química , Tragacanto/química , Agua/química , Liberación de Fármacos , Tecnología Química Verde , Polisacáridos/metabolismo
14.
Ecotoxicol Environ Saf ; 164: 722-731, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-30176561

RESUMEN

The quality of soils under different land uses is getting deteriorated throughout the world due to various anthropogenic activities. This deterioration is highly complex in riverine floodplain areas due to contamination by multiple point and non-point sources and change in seasons. Therefore, a study was conducted to analyze seasonal (pre and post-monsoon) variations in physico-chemical characteristics, contents of metal(loid)s (Al, As, Cd, Cr, Co, Cu, Fe, Mn, Mo, Ni, Pb, Sb and Zn) in riverine floodplain soils under three land uses (agricultural, riverbank and roadside) from areas around the rivers Beas and Sutlej in Punjab, India. Further, analysis was done to assess the ecological and genotoxic risks (Allium cepa genotoxicity assay) posed by metal(loid)s in these soils. It was observed that soil samples under the three land uses were slightly alkaline (pre-monsoon) to acidic (post-monsoon) in nature with sandy texture and low soil organic matter. The levels of most metal(loid)s increased in post-monsoon soil samples under the three land uses, which was attributed to increase in soil organic matter, silt and clay contents in post-monsoon samples due to precipitation, flooding and sedimentation. The ecological Risk Index (58.3-104.5) and Modified Risk Index (145.2-178.9) calculated to analyze the level of ecological risks of metal(loid)s revealed that As, Cd and Sb posed moderate to considerable ecological risks in the agricultural and roadside soils in both seasons. Allium cepa genotoxicity assay indicated that the metal(loid)s in studied soils can cause genotoxic effects in biological systems. Therefore, various steps such as reduction in use of agrochemicals, promotion of organic agricultural methods and decontamination of soils using techniques such as phytoremediation etc must be taken to ensure reduction and containment of metal(loid)s in such riverine floodplain areas.


Asunto(s)
Metales Pesados/análisis , Contaminantes del Suelo/análisis , Suelo/química , Fenómenos Químicos , Daño del ADN , Ecología , Monitoreo del Ambiente , Concentración de Iones de Hidrógeno , India , Medición de Riesgo , Estaciones del Año
15.
Int J Biol Macromol ; 114: 283-294, 2018 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-29580994

RESUMEN

In this work, an environmentally friendly gum ghatti-crosslinked-polyacrylamide (Gg-cl-PAAM) hydrogel was synthesized from gum ghatti (Gg) and acrylamide (AAM) using a microwave-assisted grafting technique, and tested for use in water purification applications as an adsorbent and flocculent. The Gg-cl-PAAM was characterized using SEM, FTIR, and TGA, and displayed pH responsive swelling behavior, with maximum swelling (2117%) observed in solution with neutral pH. The flocculation characteristics of Gg-cl-PAAM were tested in clay solutions as a function of pH, temperature, and the polymer mass loading, showing that the best performance is obtained at neutral pH at 40°C. The adsorption capacities of Gg-cl-PAAM for the removal different dyes such as brilliant green (BG), rhodamine B (RhB), congo red (CR), and methyl orange (MO) were tested, revealing that the adsorption of all dyes followed the Langmuir isotherm model, with qm values of 523.62mgg-1 for BG, 421.60mgg-1 for RhB, 179.09mgg-1 for CR, and 173.69mgg-1 for MO. Finally, the environmentally friendly nature of Gg-cl-PAAM was examined using the soil-burial composting method, which demonstrated 93% degradation of the Gg-cl-PAAM hydrogel within 60days.


Asunto(s)
Acrilamida/química , Colorantes Fluorescentes/química , Gomas de Plantas/química , Purificación del Agua/métodos , Adsorción , Floculación , Concentración de Iones de Hidrógeno
16.
RSC Adv ; 8(73): 41920-41937, 2018 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-35558783

RESUMEN

This paper deals with the synthesis of a biodegradable interpenetrating polymer network (IPN) from the natural polysaccharide aloe vera (Av), acrylamide (AAm) and acrylic acid (AA), and its evaluation as a dye removal device. In the synthesis of Av-cl-poly(AA-ipn-AAm), ammonium persulfate (APS) was used as an initiator, N,N'-methylene bisacrylamide (MBA) as a cross-linker, AA and AAm as primary and secondary monomers, respectively. Soil burial and composting methods were used to study the biodegradability of the synthesized IPN and the results showed 94% degradation within 70 days using the composting method and 86% degradation within 77 days using the soil burial method. Biodegradation was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The synthesized IPN was used as a device for the removal of malachite green (MG) dye from aqueous solution. The maximum MG removal capacity of the synthesized IPN was found to be 97.3% under the optimal conditions (i.e. time = 180 min., pH = 4.5, adsorbent dose = 5 g L-1). The adsorption kinetics of malachite green molecules onto synthesized IPN was studied and compared using pseudo-first-order and pseudo-second-order models and we found that the adsorption process is better represented by the pseudo-second-order model. The different adsorption isotherm models like Langmuir, Freundlich, Dubinin-Radushkevich, Temkin, Redlich-Peterson and Sips isotherms were studied. The best-fitting isotherm model for the present experiment is the Langmuir model.

17.
Int J Biol Macromol ; 89: 1-11, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27106587

RESUMEN

This research paper reports the utilization of gum xanthan-grafted-polyacrylic acid and Fe3O4 magnetic nanoparticles based nanocomposite hydrogel (NCH) for the highly effective adsorption of methyl violet (MV) from aqueous solution. Synthesized NCH was characterized using various techniques, such as FTIR, XRD, SEM-EDS, TEM and BET. Adsorption behavior of NCH was studied for the adsorption of MV and it was found to remove 99% dye from the solution. Adsorption process followed Langmuir isotherm model (qe=642mg/g) and pseudo-second-order kinetics model. Thermodynamic studies suggested that the adsorption process was endothermic and spontaneous. Moreover, the adsorbent was successfully utilized for successive five cycles of adsorption-desorption.


Asunto(s)
Compuestos Férricos/química , Violeta de Genciana/aislamiento & purificación , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Polisacáridos Bacterianos/química , Adsorción , Difusión , Hidrogel de Polietilenoglicol-Dimetacrilato/síntesis química , Concentración de Iones de Hidrógeno , Cinética , Modelos Teóricos , Nanocompuestos/química , Nanocompuestos/ultraestructura , Soluciones , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Difracción de Rayos X
18.
Biotechnol Rep (Amst) ; 9: 74-81, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28352595

RESUMEN

A novel interpenetrating polymer network (IPN) has been synthesized through enzymatic initiation using lipase as initiator, glutaraldehyde as cross-linker, acrylic acid as primary monomer and acrylamide as secondary monomer. Biodegradability of synthesized interpenetrating polymer network was studied through soil burial and composting methods. Synthesized hydrogel was completely degraded within 70 days using composting method, while it was 86.03% degraded within 77 days using soil burial method. This was confirmed by Fourier transform Infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) techniques. Synthesized interpenetrating polymer network hydrogel was used as a device for controlled release of urea and also act as water releasing device. Their impact on soil fertility and plant growth was also studied. The initial diffusion coefficient has a greater value than the later diffusion coefficient indicating a higher fertilizer release rate during the early stage. Fertilizer release kinetic was also studied which showed Non-Fickian diffusion behavior, as the rate of fertilizer release was comparable to the relaxation time of the synthesized matrix. Synthesized IPN enhance the water uptake capacity up to 6.2% and 7.2% in sandy loam and clay soil, respectively.

19.
J Environ Sci Eng ; 54(1): 55-63, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23741858

RESUMEN

The objective of the study was to ascertain contamination levels of soil with Polycyclic Aromatic Hydrocarbons (PAHs), their distribution behavior and human exposure during summer, winter and rainy seasons in one of the developing city of Jalandhar in the state of Punjab, India. PAHs concentration was measured at 10 different locations (within 3 m) in roadside soil, covering all major traffic intercepts of the city. Recovery range was between 30% and 70% with the lower value corresponds to the lower molecular weight PAHs compound. Identification and quantification of PAHs were done by GC-FID. Average PAHs concentrations (city average) were found to be 16.53, 4.04 and 7.82 microg g(-1), during summer, winter and rainy seasons respectively. Average concentrations of low and high carcinogenic PAHs during summer, winter and rainy seasons were found 5.1 and 31.29, 2.1 and 6.4, & 3.97 and 12.77 microg g(-1) respectively. The average ratios of low and high carcinogenic PAHs were found to be 1:6, 1:3 and 1:7.6 during summer, winter and rainy seasons at most intercepts. Dibenzo (ah) Anthracene and Benzo (a) Pyrene were the two individual PAH found in highest concentration during summer, winter and rainy seasons. It was worth also observed that high carcinogenic PAHs concentration was quite higher (around 85%) in comparison to low carcinogenic PAHs (around 15%) at most intercepts round the year. Five ringed PAHs were in highest concentration at all intercepts and seasons.


Asunto(s)
Carcinógenos Ambientales/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Suelo/análisis , Emisiones de Vehículos/análisis , Ciudades , Humanos , India , Estaciones del Año
20.
Environ Monit Assess ; 184(10): 6239-52, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22068316

RESUMEN

A study of polycyclic aromatic hydrocarbons (PAHs) pollution in roadside soil was conducted at a developing city locations of Jalandhar (Punjab), India in winter season to ascertain the contamination levels and their distribution behavior in roadside soil. PAHs concentration level of ten locations was measured at 1, 2, and 3 m distances from roadside soil covering all the major traffic intercepts within a city. Samples were extracted in acetone and dichloromethane (1:1) using soxhlet extraction. The extracts were filtered on a silica gel micro column to remove impurities and eluate was subjected to GC-FID. The total average PAHs concentration (city average) was found to be 4.04 µg g(-1), whereas the concentration of 16 individual PAHs was found to vary between 0.008 and 28.4 µg g(-1). The average concentration of noncarcinogenic and carcinogenic PAHs in all the samples was 2.17 and 6.41 µg g(-1) (ratio 1:2.95). The concentration of five ringed PAHs was found to be 45% to 60%, whereas two ringed PAHs were found to be in the range from 0.28% to 0.56% in all most all locations. The average highest PAHs concentration for any individual location was found as 12.23 µg g(-1) at DAV Chowk at 1 m distance and minimum concentration was 0.98 µg g(-1) at Maqsuda Chowk at 1 m distance from roadside. DiB (ah) A was the individual PAHs found in highest concentration in all the intercepts ranging between 1.26 and 28 µg g(-1). At most of the city intercepts, total carcinogenic PAHs concentration was found to range from 60% to 80% in comparison to noncarcinogenic PAHs (20%-40%) at most of the intercepts. The pollution level our study was compared with other cities of India/worldwide.


Asunto(s)
Automóviles/estadística & datos numéricos , Ciudades/estadística & datos numéricos , Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes del Suelo/análisis , India , Suelo/química
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