Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
BMC Microbiol ; 24(1): 269, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39030474

RESUMEN

Candida auris (C. auris) is a yeast that has caused several outbreaks in the last decade. Cell wall chitin plays a primary role in the antifungal resistance of C. auris. Herein, we investigated the potential of chitinase immobilized with UiO-66 to act as a potent antifungal agent against C. auris. Chitinase was produced from Talaromyces varians SSW3 in a yield of 8.97 U/g dry substrate (ds). The yield was statistically enhanced to 120.41 U/g ds by using Plackett-Burman and Box-Behnken design. We synthesized a UiO-66 framework that was characterized by SEM, TEM, XRD, FTIR, a particle size analyzer, and a zeta sizer. The produced framework had a size of 70.42 ± 8.43 nm with a uniform cubic shape and smooth surface. The produced chitinase was immobilized on UiO-66 with an immobilization yield of 65% achieved after a 6 h loading period. The immobilization of UiO-66 increased the enzyme activity and stability, as indicated by the obtained Kd and T1/2 values. Furthermore, the hydrolytic activity of chitinase was enhanced after immobilization on UiO-66, with an increase in the Vmax and a decrease in the Km of 2- and 38-fold, respectively. Interestingly, the antifungal activity of the produced chitinase was boosted against C. auris by loading the enzyme on UiO-66, with an MIC50 of 0.89 ± 0.056 U/mL, compared to 5.582 ± 0.57 U/mL for the free enzyme. This study offers a novel promising alternative approach to combat the new emerging pathogen C. auris.


Asunto(s)
Antifúngicos , Candida auris , Quitinasas , Pruebas de Sensibilidad Microbiana , Nanopartículas , Quitinasas/farmacología , Quitinasas/metabolismo , Quitinasas/química , Antifúngicos/farmacología , Antifúngicos/química , Nanopartículas/química , Candida auris/efectos de los fármacos , Candida auris/genética , Enzimas Inmovilizadas/química , Talaromyces/efectos de los fármacos , Talaromyces/química , Talaromyces/enzimología , Farmacorresistencia Fúngica Múltiple , Hidrólisis , Quitina/química , Quitina/farmacología
2.
BMC Plant Biol ; 22(1): 544, 2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36434510

RESUMEN

Calcareous soil contains many problems such as the lack of sources of major and minor elements that are useful for plant growth and development. Plant extracts and nanoparticles are very popular as biostimulants in plant production. Here, the effect of aqueous, non-aqueous and alcoholic oat extracts on the growth, biochemical response of oats leaves and grains grown in experimental fields under new reclamation lands were studied. Moreover, different oat extracts were a pathway through the copper-dependent metal-organic framework (MOFs) to separate bioactive molecules from extracts such as salicylic acid, anthraquinone, and triacylglycerol. Additionally, the separated molecules incorporated in Cu-BTC MOFs and oats extracts missed active molecules were spray applied on oat plants. The results showed that the treated plants showed stimulatory responses in growth and physiology. The treatments improved plant growth and biomass, enhanced total protein, water-soluble carbohydrates, free phenolic compounds content in oat leaves, photosynthesis, and chlorophyll contents. The treatments also improved the level of vitamins E and K, phenolic compounds, and avenanthramides C in the oat grains. Moreover, the treatments showed an improvement in the yield of oats (grain and straw) using water and alcoholic oat extracts in which the active molecules were missed. Our findings demonstrate that Cu-BTC and oats extracts can act as a biostimulant to enhance the biological and chemical properties of oats and increase the yield in calcareous soils. The cytotoxicity study of oats (produced from AE, c@Cu-BTC, and AE-c treatments) was conducted using Vero Cell lines. The anticancer activities of different oat grains were carried out using MCF 7cell lines. The results show that the grains produced from the AE, c@Cu-BTC, and AE-c treatments possessed 94.3, 72.3, and 100% activity towards the cancer cell line. Removal of growth inhibitors from spray solutions increases grain yield and anticancer activity.


Asunto(s)
Avena , Suelo , Avena/metabolismo , Suelo/química , Grano Comestible/química , Semillas , Fenoles/metabolismo
3.
J Mater Sci Mater Med ; 31(11): 90, 2020 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-33089411

RESUMEN

Toxoplasmosis is a zoonotic protozoal disease caused by Toxoplasma gondii, an intracellular opportunistic protozoan parasite that can infect any warm-blooded vertebrate cell. In this study, zirconium, and iron-based metal-organic framework was prepared according to the solvothermal method. New nanocomposite (Curcumin@MOFs) was prepared by reacting curcumin with amino-functionalized metal-organic frameworks (Fe-MOF and UiO-66-NH2). Besides characterizations of the composite by powder X-ray diffraction and scanning electron microscope, nano-Curcumin@MOFs was used as a new novel structure as atrial for treatment of chronic toxoplasmosis. Results showed a reduced number of brain cysts, high levels of serum Toxo IgG, and normal histo-morphology with preserved parenchymal, and stromal tissues in rats groups treated with curcumin and Curcumin@MOFs nanocomposite.


Asunto(s)
Curcumina/química , Estructuras Metalorgánicas/química , Nanocompuestos/química , Toxoplasmosis/tratamiento farmacológico , Animales , Productos Biológicos/química , Encéfalo/efectos de los fármacos , Encéfalo/parasitología , Enfermedad Crónica/terapia , Femenino , Inmunoglobulina G/química , Hígado/metabolismo , Microscopía Electrónica de Rastreo , Nanomedicina/métodos , Porosidad , Polvos , Ratas , Espiramicina/química , Bazo/metabolismo , Toxoplasma , Difracción de Rayos X , Circonio/química
4.
Chemistry ; 21(31): 11072-81, 2015 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-26095013

RESUMEN

NH2 -MIL-125, [Ti8 O8 (OH)4 (bdc-NH2 )6 ] (bdc(2-) =1,4-benzene dicarboxylate) is a highly porous metal-organic framework (MOF) that has a band gap lying within the ultraviolet region at about 2.6 eV. The band gap may be reduced by a suitable post-synthetic modification of the nanochannels using conventional organic chemistry methods. Here, it is shown that the photocatalytic activity of NH2 -MIL-125 in the degradation of methylene blue under visible light is remarkably augmented by post-synthetic modification with acetylacetone followed by Cr(III) complexation. The latter metal ion extends the absorption from the ultraviolet to the visible light region (band gap 2.21 eV). The photogenerated holes migrate from the MOF's valence band to the Cr(III) valence band, promoting the separation of holes and electrons and increasing the recombination time. Moreover, it is shown that the MOF's photocatalytic activity is also much improved by doping with Ag nanoparticles, formed in situ by the reduction of Ag(+) with the acetylacetonate pendant groups (the resulting MOF band gap is 2.09 eV). Presumably, the Ag nanoparticles are able to accept the MOF's photogenerated electrons, thus avoiding electron-hole recombination. Both, the Cr- and Ag-bearing materials are stable under photocatalytic conditions. These findings open new avenues for improving the photocatalytic activity of MOFs.

5.
Sci Rep ; 14(1): 15608, 2024 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-38971874

RESUMEN

Urea used in fertilization and feed supplement, as well as a starting material for the manufacture of plastics and drugs. Urea is most commonly produced by reacting carbon dioxide with ammonia at high temperature. Photocatalysis has gained attention as a sustainable pathway for performing urea. This work focus on designing very active photocatalysts based on cerium organic framework (Ce-BTC) doped with metal oxide nanoparticles (molybdenum permanganate, Mo(MnO4)5) for production of urea from coupling of ammonia with carbon dioxide. The prepared materials were characterized using different spectral analysis and the morphology was analysed using microscopic data. The effect of catalyst loading on the production rate of urea was investigated and the obtained results showed speed rate of urea production with high production yield at low temperature. The recyclability tests confirmed the sustainability of the prepared photocatlysts (Mo(MnO4)5@Ce-BTC) which supported the beneficial of the photocatalysis process in urea production.

6.
Int J Biol Macromol ; 256(Pt 1): 128419, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38013080

RESUMEN

Chitosan-based aerogels were fabricated through utilizing of nanofibrillated cellulose (NFC)/CaCO3 composites. Chitosan aerogel and extra three aerogels loaded different concentrations of NFC/CaCO3 were investigated to explore their release efficiency of Tebuconazole pesticides. Results obtained from ATR-FTIR showed a remarkable decline of the characterized chitosan hydroxyl group peak prolonging with appearance of new peaks assigned to the inclusion of inorganic calcium element. Also, SEM images showed chitosan aerogel with regular porous structure increased by incorporation with of NFC/CaCO3 nanocomposite, while EDS affirmed the presence of calcium element rather pristine chitosan aerogel. In addition to this, the physical characterizations showed significant improvement in swelling properties for aerogels incorporated NFC/CaCO3 nanocomposite at low ratios. Chitosan aerogel reinforced NFC/CaCO3 nanocomposite exhibited benefit on loading and release efficiency of Tebuconazole. All samples showed accessibility to column release method with fastest release at low slow rate 2 mL/min as giving chance for diffusion and solubility of ingredient, while release increase as heat increase as result of pore expansion. In conclusion, chitosan aerogels incorporated calcium carbonate showed better-sustained release of Tebuconazole pesticides than pristine chitosan aerogel. The produced aerogels loaded NFC/CaCO3 nanocomposite could be promising for controlled release of pesticides at water-streams in agriculture sector.


Asunto(s)
Quitosano , Nanocompuestos , Plaguicidas , Triazoles , Quitosano/química , Celulosa/química , Calcio , Preparaciones de Acción Retardada
7.
Plant Physiol Biochem ; 211: 108655, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38744086

RESUMEN

The challenge of desert farming with a high salt level has become an ecological task due to salt stress negatively affecting plant growth and reproduction. The current study deals with the cultivation of sorghum under salt stress conditions to counteract the effect of chitosan and gibberellic acid (GA3). Here, the effects of chitosan, GA3 and nano-composite (GA3@chitosan) on biochemical contents, growth and seed yield of sorghum under salinity stress conditions were studied. The results showed that spraying with GA3@chitosan increased sorghum grain yield by 2.07, 1.81 and 1.64 fold higher than salinity stressed plants, chitosan treatment and GA3 treatment, respectively. Additionally, compared to the control of the same variety, the GA3@chitosan spraying treatment improved the concentration of microelements in the grains of the Shandweel-1 and Dorado by 24.51% and 18.39%, respectively for each variety. Furthermore, spraying GA3@chitosan on sorghum varieties increased the accumulation of the macroelements N, P, and K by 34.03%, 47.61%, and 8.67% higher than salt-stressed plants, respectively. On the other hand, the proline and glycinebetaine content in sorghum leaves sprayed with nano-composite were drop by 51.04% and 11.98% less than stressed plants, respectively. The results showed that, in Ras Sudr, the Shandweel-1 variety produced more grain per feddan than the Dorado variety. These findings suggest that GA3@chitosan improves the chemical and biochemical components leading to a decrease in the negative effect of salt stress on the plant which reflects in the high-yield production of cultivated sorghum plants in salt conditions.


Asunto(s)
Quitosano , Giberelinas , Estrés Salino , Sorghum , Sorghum/efectos de los fármacos , Sorghum/metabolismo , Sorghum/crecimiento & desarrollo , Giberelinas/metabolismo , Giberelinas/farmacología , Estrés Salino/efectos de los fármacos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo
8.
Environ Sci Pollut Res Int ; 31(9): 13185-13206, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38240971

RESUMEN

To effectively remove pharmaceuticals, nitroaromatic compounds, and dyes from wastewater, an efficient multifunctional material was created based on silver nanoparticles (Ag) and MIL-125-NH2 (MOF) immobilized on viscose fibers (VF) as a support substrate. Firstly, silver nanoparticles (Ag) were immobilized on the surface of viscose fibers (VF) via in situ synthesis using trisodium citrate (TSC) as a reducing agent to create (VF-Ag). Then, VF and VF-Ag were decorated with the titanium metal-organic framework MIL-125-NH2 (MOF) to create VF-MOF and VF-Ag-MOF. The influence of VF-Ag, VF-MOF, and VF-Ag-MOF on the sonocatalytic or sonophotocatalytic degradation of sulfa drugs was investigated. The results show that VF-Ag-MOF showed excellent sonocatalytic and sonophotocatalytic activity towards the degradation of sulfa drugs compared to VF-Ag and VF-MOF. Furthermore, sonophotodegradation showed a dramatic enhancement in the efficiency of degradation of sulfa drugs compared to sonodegradation. The sonophotodegradation degradation percentage of sulfanilamide, sulfadiazine, and sulfamethazine drugs in the presence of VF-Ag-MOF was 65, 90, and 95 after 45 min of ultrasonic and visible light irradiation. The catalytic activity of VF-Ag, VF-MOF, and VF-Ag-MOF was evaluated through the conversion of p-nitrophenol (4-NP) to p-aminophenol (4-AP). The results demonstrate that VF-Ag-MOF had the highest catalytic activity, followed by VF-Ag and VF-MOF. The conversion percentage of 4-NP to 4-AP was 69%. The catalytic or photocatalytic effects of VF-Ag, VF-MOF, and VF-Ag-MOF on the elimination of methylene blue (MB) dye were investigated. The results demonstrate that VF-Ag-MOF showed high efficiency in removing the MB dye through the reduction (65%) or photodegradation (71%) after 60 min. VF-Ag-MOF composites structure-activity relationships represent that doping within silver NPs enhanced the photocatalytic activity of MIL-125-NH2, which could be explained as follows: (i) Due to the formation of a Schottky barrier at the junction between MIL-125-NH2 and Ag NPs, the photogenerated electrons in the conduction band of MIL-125-NH2 were supposed to be quickly transferred to the valence band of the Ag NPs, and subsequently, the electrons were transferred to the conduction band of Ag NPs. This considerable electron transferring process, which is reported as Z scheme heterojunction, can efficiently suppress the recombination of electron/hole pairs in VF-Ag-MIL-125-NH2 composites. (ii) Sufficient separation between the photogenerated charge carriers (holes and electrons) and avoiding their recombination enhanced the photocatalytic activity of composites.


Asunto(s)
Nanopartículas del Metal , Plata , Plata/química , Nanopartículas del Metal/química , Titanio/química , Luz , Fotólisis
9.
Int J Biol Macromol ; 279(Pt 1): 135148, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39214202

RESUMEN

The accumulation of uremic toxins in the human body poses a deadly risk because it causes chronic kidney disease. To increase the effectiveness of hemodialysis and raise the survival rate, these toxins must be effectively removed from the bloodstream. Developing effective materials for removing these dangerous substances requires a thorough understanding of the interactions between an adsorbent and the uremic toxins. Thankfully, metal-organic frameworks (MOFs) have shown considerable promise for the identification and treatment of kidney disorders. Herein, cotton gauze fabrics (CGF) were carboxylated using monochloroacetic acid to produce carboxymethylated cotton gauze fabrics (CM-CGF). CM-CGF was subsequently decorated in situ with zeolitic imidazolate framework-67, resulting in carboxymethylated cotton gauze fabrics-zeolitic imidazolate framework-67 (CM-CGF-ZIF). The CGF, CM-CGF, and CM-CGF-ZIF were evaluated for potential kidney applications by removing uric acid and creatinine from mimic blood. The results showed that CM-CGF-ZIF had the highest adsorption of uric acid and creatinine. The maximum adsorption capacity of uric acid and creatinine was 164 and 222 mg/g for CM-CGF-ZIF, respectively, compared to 45 and 67 mg/g for CGF. CM-CGF-ZIF showed excellent antibacterial activity, good antifungal activity, low cytotoxicity, and a satisfactory level of blood compatibility.

10.
J Chromatogr A ; 1732: 465192, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39079363

RESUMEN

Metal-organic frameworks (MOFs) are a fascinating family of crystalline porous materials made up of metal clusters and organic linkers. In comparison with other porous materials, MOFs have unique characteristics including high surface area, homogeneous open cavities, and permanent high porosity with variable shapes and sizes. For these reasons, MOFs have recently been explored as sorbents in sample preparation by solid-phase extraction (SPE). However, SPE requires large amounts of sorbents and suffers from limited contact surfaces with analytes, which compromises extraction recovery and efficiency. Dispersive SPE (D-SPE) overcomes these limitations by dispersing the sorbents into the sample, which in turn increases contact with the analytes. Miniaturization of the microextraction procedure, particularly the amount of sorbent reduces the amount consumed of the organic solvent and shorten the time required to attain the equilibrium state. This may explain the reported high efficiency and applicability of MOFs in dispersive micro SPE (D-µ-SPE). This method retains all the advantages of solid phase extraction while also being simpler, faster, cheaper, and, in some cases, more effective in comparison with D-SPE. Besides, D-µ-SPE requires smaller amounts of the sorbents which reduces the overall cost, and the amount of waste generated from the analytical process. In this review, we discuss the applications of MOFs in D-µ-SPE of various analytes including pharmaceuticals, pesticides, organic dyes from miscellaneous matrices including water samples, biological samples and food samples.


Asunto(s)
Estructuras Metalorgánicas , Microextracción en Fase Sólida , Estructuras Metalorgánicas/química , Microextracción en Fase Sólida/métodos , Extracción en Fase Sólida/métodos , Adsorción , Contaminantes Químicos del Agua/aislamiento & purificación , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Porosidad
11.
Plant Physiol Biochem ; 201: 107844, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37422946

RESUMEN

The behavior of multi-walled carbon nanotubes (MWCNTs) and titanium dioxide nanoparticles (TiO2 NPs) as plant growth enhancers was still unclear; however, in this study, the effects of MWCNTs, TiO2NPs, 5%TiO2@MWCNTs, 10%TiO2@MWCNTs and 15%TiO2@MWCNTs on physical and biochemical contents in Sesamum indicum L. under heat stress conditions were studied. The content of malondialdehyde (MDA) and hydrogen peroxide (H2O2) concentrations were reduced by the spraying MWCNTs and TiO2 NPs on plants. The hydrogen peroxide (H2O2) content was reduced by 49.02% in plants treated with 15%TiO2@MWCNTs while 42.14% reduction was found in plants treated with 10%TiO2@MWCNTs. The proportion of oil and the peroxidase enzyme activity in plants treated with 15%TiO2@MWCNTs were increased by 48.99%, for the oil content, and 2.39 times for POD activity respected to the stressed plants. The proportion of unsaturated fatty acids increased in plants treated with 15%TiO2@MWCNTs, 10%TiO2@MWCNTs and TiO2 NPs by 2.7, 2.52, and 2.09 times, respectively, greater than the control of the Shandweel-3 variety. Finally, plants treated with 15%TiO2@MWCNTs showed increases in seed yield and weight 1000-seeds by 4.42 and 1.67 times, respectively. These findings suggest that TiO2@MWCNTs more effective than separated MWCNTs and TiO2 NPs in improve plant growth. In addition, the cultivar Shandweel-3 showed an improvement in growth indicators more than the Giza-32 cultivar.


Asunto(s)
Nanopartículas , Nanotubos de Carbono , Sesamum , Peróxido de Hidrógeno , Antioxidantes , Titanio/farmacología , Respuesta al Choque Térmico
12.
Discov Nano ; 18(1): 75, 2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-37382711

RESUMEN

Microbial resistance is the first morbidity and mortality cause for patients as usually a secondary infection. Additionally, the MOF is a promising material that shows a nice activity in this field. However, these materials need a good formulation to enhance biocompatibility and sustainability. Cellulose and its derivatives are well as filers for this gap. In this presented work, a novel green active system based on carboxymethyl cellulose and Ti-MOF (MIL-125-NH2@CMC) modified with thiophene (Thio@MIL-125-NH2@CMC) was prepared by a post-synthetic modification (PSM) route based. FTIR, SEM and PXRD were utilized to characterize nanocomposites. In addition, transmission electron microscopy (TEM) was used to corroborate the nanocomposites' particle size and diffraction pattern as well as the DLS affirmed the size as 50 and 35 nm for MIL-125-NH2@CMC and Thio@MIL-125-NH2@CMC, respectively. The formulation of the nanocomposites was validated by physicochemical characterization techniques, while morphological analysis confirmed the nanoform of the prepared composites. The antimicrobial, antiviral and antitumor properties of MIL-125-NH2@CMC and Thio@MIL-125-NH2@CMC were assessed. Antimicrobial testing revealed that Thio@MIL-125-NH2@CMC possesses greater antimicrobial activity than MIL-125-NH2@CMC. Additionally, Thio@MIL-125-NH2@CMC demonstrated promising antifungal activity against C. albicans and A. niger where MICs were 31.25 and 0.97 µg/mL, respectively. Also, Thio@MIL-125-NH2@CMC exhibited antibacterial activity against E. coli and S. aureus where MICs were 1000 and 250 µg/mL, respectively. In addition, the results demonstrated that Thio@MIL-125-NH2@CMC displayed promising antiviral activity against both HSV1 and COX B4, with antiviral activities of 68.89% and 39.60%, respectively. Furthermore, Thio@MIL-125-NH2@CMC exhibited potential anticancer activity against MCF7 and PC3 cancerous cell lines, where IC50 was 93.16 and 88.45%, respectively. In conclusion, carboxymethyl cellulose/sulfur-functionalized Ti-based MOF composite was successfully synthesized which had antimicrobial, antiviral and anticancer activities.

13.
Environ Sci Pollut Res Int ; 30(49): 106860-106875, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36847947

RESUMEN

Green synthesis of metal-organic frameworks (MOFs) has attracted a lot of attention as a crucial step for practical industrial applications. In this work, green synthesis of zinc(II) metal-organic framework (Zn-MOF) has been carried out at room temperature. The Zn metal (node) was extracted from spent domestic batteries, and the linker was benzene di-carboxylic acid (BDC). The characterization of the as-prepared Zn-MOF was accomplished by PXRD, FT-IR spectroscopy, SEM, TEM, TGA, and nitrogen adsorption at 77 K. All the characterization techniques strongly supported that as-synthesized Zn-MOF using metallic solid waste Zn is similar to that was reported in the literature. The as-prepared Zn-MOF was stable in water for 24 h without any changes in its functional groups and framework. The prepared Zn-MOF was tested for the adsorption of three dyes, two anionic dyes, aniline blue (AB), and orange II (O(II)) as well as methylene blue (MB), an example of cationic dye from aqueous solution. AB has the highest equilibrium adsorbed amount, qe, of value 55.34 mg g-1 at pH = 7 and 25 °C within 40 min. Investigation of the adsorption kinetics indicated that these adsorption processes could be described as a pseudo-second-order kinetic model. Furthermore, the adsorption process of the three dyes was described well by the Freundlich isotherm model. According to the thermodynamic parameters, the adsorption of AB on the prepared Zn-MOF was an endothermic and spontaneous process. In contrast, it was non-spontaneous and exothermic for the uptake of O(II) and MB. This study complements the business case development model of "solid waste to value-added MOFs."


Asunto(s)
Colorantes , Contaminantes Químicos del Agua , Colorantes/química , Espectroscopía Infrarroja por Transformada de Fourier , Análisis Costo-Beneficio , Residuos Sólidos , Termodinámica , Agua/química , Cinética , Zinc/química , Adsorción , Contaminantes Químicos del Agua/análisis
14.
Int J Biol Macromol ; 240: 124498, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37076079

RESUMEN

The application of newly formulated beads from copper-benzenetricarboxylate (Cu-BTC), polyacrylonitrile (PAN), and chitosan (C), Cu-BTC@C-PAN, C-PAN, and PAN, for the removal of phenolic chemicals from water, is described in the current paper. Phenolic compounds (4-chlorophenol (4-CP) and 4-nitrophenol (4-NP)) were adsorbed using beads and the adsorption optimization looked at the effects of several experimental factors. The Langmuir and Freundlich models were used to explain the adsorption isotherms in the system. A pseudo-first and second-order equation is performed for describing the kinetics of adsorption. The obtained data fit (R2 = 0.999) supports the suitability of the Langmuir model and pseudo-second-order kinetic equation for the adsorption mechanism. Cu-BTC@C-PAN, C-PAN, and PAN beads' morphology and structure were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transforms infrared spectroscopy (FT-IR). According to the findings, Cu-BTC@C-PAN has very high adsorption capacities of 277.02, and 324.74 mg g-1, for 4-CP and 4-NP, respectively. The Cu-BTC@C-PAN beads showed 2.55 times higher adsorption capacity than PAN in the case of 4-NP, but in the case of 4-CP, it was higher by 2.64 times.


Asunto(s)
Quitosano , Estructuras Metalorgánicas , Contaminantes Químicos del Agua , Quitosano/química , Cobre/química , Adsorción , Espectroscopía Infrarroja por Transformada de Fourier , Concentración de Iones de Hidrógeno , Fenoles , Cinética , Contaminantes Químicos del Agua/química
15.
Sci Rep ; 13(1): 15208, 2023 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-37709829

RESUMEN

Chlorophyll-a as pigments, exist in the green organelles for plants that act in photosynthesis. Different studies were considered with demonstration of an effective separation technique of Chlorophyll-a without decomposition; however, the reported methods were disadvantageous with expensiveness and low quantum yield. The current work uniquely represents an investigative method for the separation of Chlorophyll-a from spinach extract using cellulosic hybrids based on ZIF-8 @cellulosic fibers (Zn-zeolitic imidazolate frameworks@cellulosic fibers) as a cost effective and recyclable absorbents. To obtain hybrids, ZIF-8 was in-situ prepared over the cellulosic fibers (bamboo, modal and cotton). The untreated and treated fibers were well characterized via FTIR, SEM, EDX, XRD, in order to approve the successive impregnation of ZIF-8. Whereas, the microscopic images showed that, microcrystalline ZIF-8 rods with length of 1.3-4.4 µm were grown over the cellulosic fibers. The obtained hybrids and the untreated fibers were exploited in the separation of Chlorophyll-a via the adsorption/desorption process. The chlorophyll-adsorption was followed Langmuir isotherm and pseudo-second order model. The Langmuir maximum capacities of Chlorophyll-a onto hybrids were followed the order of ZIF-8@cotton (583.6 mg/g) > ZIF-8@modal (561.3 mg/g) > ZIF-8@bamboo (528.7 mg/g). After incorporation of ZIF-8, the maximum adsorption capacities of cellulosic fibers were enhanced by 1.4-1.9 times. Adsorption of chlorophyll onto the applied hybrids was lowered by 27-28%, after five repetitive washing cycles. The data summarized that; chlorophyll was effectively separated by the synthesized ZIF-8@cellulosic fibers hybrids, whereas, the prepared hybrids showed good reusability for application on wider scaled purposes.


Asunto(s)
Clorofila , Fotosíntesis , Clorofila A , Adsorción , Gossypium , Zinc
16.
J Pharm Biomed Anal ; 235: 115609, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37557067

RESUMEN

Solid phase microextraction (SPME) is considered simple, ecofriendly, sustainable, cost-effective and timesaving sample preparation mode in comparison with other sample preparation procedures. The researchers always try to develop new sorbents with higher surface area in comparison with other conventional sorbents aiming to enhance the extraction efficiency. In this work for the first time, a comparative study was performed between Ca-BTC MOF (1,3,5-benzenetricarboxylic acid, BTC; metal-organic framework, MOF) and a hybrid Ca-BTC-MCC MOF (microcrystalline cellulose, MCC) by using as model compounds seven drugs with different physicochemical properties. The evaluation of the extraction efficiency of both sorbents were obtained by means of an HPLC/DAD instrument configuration in reversed phase mode under isocratic elution mode. The results indicate that Ca-BTC MOF showed superior extraction efficiency than Ca-BTC-MCC MOF in the case of all analytes except nirmatrelvir and ritonavir. The results highlight that not only the surface area of adsorbents controlled the adsorption capacity, but also other factors have a role in extraction efficiency including morphology of adsorbent and physico-chemical properties of the analytes. It is worth mentioning that this is the first time that a comparative study was performed between Ca-BTC MOF and Ca-BTC-MCC MOF hybrid material.


Asunto(s)
Estructuras Metalorgánicas , Microextracción en Fase Sólida , Microextracción en Fase Sólida/métodos , Estructuras Metalorgánicas/química , Celulosa/química , Preparaciones Farmacéuticas
17.
J Parasit Dis ; 47(3): 591-607, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37520202

RESUMEN

Toxoplasma gondii is an opportunistic intracellular protozoon which may cause severe disease in the immunocompromised patients. Unfortunately, the majority of treatments on the market work against tachyzoites in the acute infection but can't affect tissue cysts in the chronic phase. So, this study aimed to evaluate the effect of bee venom (BV) loaded metal organic frameworks (MOFs) nanoparticles (NPs) for the treatment of chronic murine toxoplasmosis. Ninety laboratory Swiss Albino mice were divided into 9 groups (10 mice each); GI (negative control), GII (infected control), GIII-GXI (infected with Me49 strain of Toxoplasma and treated); GIII (MOFs-NPs), GIV and GV (BV alone and loaded on MOFs-NPs), GVI and GVII (spiramycin alone and loaded on MOFs-NPs), GVIII and GIX (ciprofloxacin alone and loaded on MOFs-NPs). Parasitological examination of brain cyst count, histopathological study of brain, retina, liver, and kidney tissue sections and immunohistochemical (IHC) evaluation of liver was performed. Counting of Toxoplasma brain cysts showed high statistically significant difference between the infected treated groups and GII. GV showed the least count of brain cysts; mean ± SD (281 ± 29.5). Histopathological examination revealed a marked ameliorative effect of BV administration when used alone or loaded MOFs-NPs. It significantly reduced tissue inflammation, degeneration, and fibrosis. IHC examination of liver sections revealed high density CD8+ infiltration in GII, low density CD8+ infiltration in GIII, GVI, GVII, GVIII, and GIX while GIV and GV showed intermediate density CD8+ infiltration. BV is a promising Apitherapy against chronic toxoplasmosis. This effect is markedly enhanced by MOFs-NPs.

18.
Environ Sci Pollut Res Int ; 29(28): 43287-43299, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35091930

RESUMEN

Paracetamol is a ubiquitous drug used by animals and humans but is not fully metabolized within their bodies, and thus often finds its way into raw wastewater. This study represents a new class of adsorbent nanocomposite with high adsorption capacity towards paracetamol removal. Herein, both the kinetic study and the removal of paracetamol from aqueous solutions were investigated in terms of diverse CaCO3/nanocellulose composites with different surface charges and different particle sizes. To fine-tune these parameters, the latter was hydrothermally synthesized by manipulating of three nanocelluloses types. Precisely, micro-crystalline cellulose (MCC), nano-crystalline cellulose (CNC), and nano-fibrillated cellulose (NFC) were used as templates for precipitating CaCO3 particles from CaCl2 solution with the aid of Na2CO3. Results revealed the successful in situ deposition of calcite form of CaCO3 with size varied relying on the base of nanocellulose. For MCC, CNC, and NFC, the size of CaCO3 was disclosed in the range of 850-1200 nm, 350-600 nm, and 150-200 nm, respectively, regarding their surface charge. While the process of paracetamol adsorption was described by Freundlich and Langmuir isotherms, it was observed that, for MCC, the best fit of the experimental data was achieved with the Freundlich model, while the Langmuir model was the most appropriate for CNC and NFC. Also, the highest max adsorption capacities of paracetamol varied respectively to both size and surface charge of hybrid composite used. Among them, MCC/CaCO3 composite exhibited the highest max adsorption capacity at 428 mg g-1, clarifying that the low surface zeta potential of the latter hybrid nanocomposite is responsible for the accumulation of CaCO3 at a bigger size with a higher affinity to adsorb paracetamol with the highest capacity due to its weak repulsion. Results also demonstrated that the material is highly effective and economical for removal of paracetamol and reusability with marginal diminishing in adsorption capacity up to 10% after five reuse cycles.


Asunto(s)
Nanocompuestos , Contaminantes Químicos del Agua , Acetaminofén , Adsorción , Celulosa/química , Cinética , Nanocompuestos/química , Agua , Contaminantes Químicos del Agua/análisis
19.
J Colloid Interface Sci ; 607(Pt 1): 334-346, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34509108

RESUMEN

Water pollution by pharmaceuticals is currently a great concern due to their ecological risks. In this study, zirconium-based metal-organic frameworks (UiO-66-(COOH)2) were used for removal of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac sodium (DCF). They have been synthesized using a hydrothermal method. Copper and iron metal ions were incorporated in the framework using post-synthetic modification techniques to produce UiO-66-(COOCu)2 and UiO-66-(COOFe)2. The resulted MOFs were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning/transmission electron microscopy, and Brunauer-Emmett-Teller. The effects of the pH, initial concentration, and adsorption time on the adsorption process of diclofenac were studied. The maximum adsorption capacities obtained on UiO-66-(COOH)2, UiO-66-(COOCu)2, and UiO-66-(COOFe)2 were 480.5, 624.3, and 769.1 mg/g, respectively. The adsorption of diclofenac was found to be better fitted with Langmuir isotherm and pseudo-second-order kinetic models. The adsorption mechanism was investigated using XRD, FT-IR, density functional theory and Monte Carlo simulation, in which the latter method was used to calculate the adsorption energies and determine the possible interactions between diclofenac and the adsorbents. UiO-66-(COOH)2, UiO-66-(COOCu)2, and UiO-66-(COOFe)2 exhibited good recyclability for diclofenac removal, which confirms the sustainability of these materials.


Asunto(s)
Estructuras Metalorgánicas , Adsorción , Diclofenaco , Modelos Teóricos , Espectroscopía Infrarroja por Transformada de Fourier , Circonio
20.
Front Chem ; 10: 1102920, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36688034

RESUMEN

Photocatalysis is an eco-friendly promising approach to the degradation of textile dyes. The majority of reported studies involved remediation of dyes with an initial concentration ≤50 mg/L, which was away from the existing values in textile wastewater. Herein, a simple solvothermal route was utilized to synthesize CoFe2O4@UiO-66 core-shell heterojunction photocatalyst for the first time. The photocatalytic performance of the as-synthesized catalysts was assessed through the photodegradation of methylene blue (MB) and methyl orange (MO) dyes at an initial concentration (100 mg/L). Under simulated solar irradiation, improved photocatalytic performance was accomplished by as-obtained CoFe2O4@UiO-66 heterojunction compared to bare UiO-66 and CoFe2O4. The overall removal efficiency of dyes (100 mg/L) over CoFe2O4@UiO-66 (50 mg/L) reached >60% within 180 min. The optical and photoelectrochemical measurements showed an enhanced visible light absorption capacity as well as effective interfacial charge separation and transfer over CoFe2O4@UiO-66, emphasizing the successful construction of heterojunction. The degradation mechanism was further explored, which revealed the contribution of holes (h+), superoxide (•O2 -), and hydroxyl (•OH) radicals in the degradation process, however, h+ were the predominant reactive species. This work might open up new insights for designing MOF-based core-shell heterostructured photocatalysts for the remediation of industrial organic pollutants.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA