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1.
ACS Appl Mater Interfaces ; 16(37): 49030-49040, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39226320

RESUMEN

Foodborne illnesses caused by Salmonella bacteria pose a significant threat to public health. It is still challenging to detect them effectively. Herein, biotemplated Janus disk-shaped magnetic microrobots (BJDMs) based on diatomite are developed for the highly efficient detection of Salmonella in milk. The BJDMs were loaded with aptamer, which can be magnetically actuated in the swarm to capture Salmonella in a linear range of 5.8 × 102 to 5.8 × 105 CFU/mL in 30 min, with a detection limit as low as 58 CFU/mL. In addition, the silica surface of BJDMs exhibited a large specific surface area to adsorb DNA from captured Salmonella, and the specificity was also confirmed via tests of a mixture of diverse foodborne bacteria. These diatomite-based microrobots hold the advantages of mass production and low cost and could also be extended toward the detection of other types of bacterial toxins via loading different probes. Therefore, this work offers a reliable strategy to construct robust platforms for rapid biological detection in practical applications of food safety.


Asunto(s)
Tierra de Diatomeas , Salmonella , Tierra de Diatomeas/química , Salmonella/aislamiento & purificación , Animales , Leche/microbiología , Microbiología de Alimentos , Límite de Detección , Aptámeros de Nucleótidos/química , Dióxido de Silicio/química , Técnicas Biosensibles/métodos
2.
Bioresour Technol ; 410: 131268, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39142416

RESUMEN

This study uncovered the response of novel micro-granule wastewater treatment technology to different powder carrier materials. Characteristics and distinctions among different systems were assessed based on process performance, sludge aggregation capacity, and microbial metabolism. Zeolite carrier system exhibited remarkable nitrogen removal efficiency of 89.6 ± 0.9 %, while diatomite carriers, in conjunction with intermittent aeration, enhanced simultaneous nitrification and denitrification from 2.6 % to 27.1 %. Iron-based carriers demonstrated efficient phosphorus removal (94.7 ± 1.2 %) through both chemical and microbial pathways. Specific surface area, pore structure and biocompatibility of powder carriers determined the formation and size of micro-granules. Tryptophan-like substances, C-(C/H), and Npr in extracellular polymeric substances strongly correlated with sludge hydrophobicity and granulation. Significant enrichment in norank_Comamonadaceae and Nitrosomonas in zeolite powder carrier system promoted partial nitrification and endogenous denitrification. Differences in metabolic pathways elucidated the up-regulation of amino acid synthesis, energy metabolism, and membrane transport as potential mechanisms driving micro-granule formation and efficient treatment performance.


Asunto(s)
Polvos , Aguas del Alcantarillado , Aguas Residuales , Purificación del Agua , Zeolitas , Aguas del Alcantarillado/microbiología , Zeolitas/química , Purificación del Agua/métodos , Aguas Residuales/química , Nitrógeno , Tierra de Diatomeas/química , Fósforo , Nitrificación , Desnitrificación , Eliminación de Residuos Líquidos/métodos , Bacterias/metabolismo
3.
Environ Pollut ; 359: 124758, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39154881

RESUMEN

Due to the extensive use of plastic products and unreasonable disposal, nanoplastics contamination has become one of the important environmental problems that mankind must face. The composition and structure of porous media can determine the complexity and diversity of the transport behavior of nanoplastics. In this study, the influence of diatomite (DIA) on the nanoplastics transport in porous media is investigated by column experiments combined with XDLVO interaction energy and transport model. Results suggest that the recovery rates of unmodified polystyrene nanoparticles (PSNPs) and carboxyl-modified polystyrene nanoparticles (PSNPs-COOH) in the porous media containing DIA decreases compared with that in the pure quartz sand (QS), and the BTCs showed a "blocking" pattern. The presence of DIA inhibits the transport of both PSNPs and PSNPs-COOH, but the inhibition is not significant. This may be because the presence of DIA provides more favorable deposition sites for PSNPs and PSNPs-COOH to some extent. However, since DIA itself carries a certain negative charge, this can only play a role in compressing the double electric layer for PSNPs and PSNPs-COOH with the same negative charge, and cannot destabilize them. The migration capacity of PSNPs and PSNPs-COOH is strongest in the DIA-QS porous media at pH = 7, and is weak at pH = 9 and pH = 5. The inhibition of migration at pH = 9 can be attributed to the dissolution of the DIA surface under alkaline conditions and the formation of pore and defect structures, which provide more deposition sites for PSNPs and PSNPs-COOH. The presence of humic acid (HA) leads to an increase in the mobility of PSNPs and PSNPs-COOH, and the mobility is enhanced with HA concentration. The mobility of PSNPs and PSNPs-COOH in DIA-QS decreases with ionic valence and ionic strength, and PSNPs-COOH is more significantly inhibited compared to PSNPs.


Asunto(s)
Nanopartículas , Poliestirenos , Porosidad , Nanopartículas/química , Poliestirenos/química , Tierra de Diatomeas/química , Microplásticos/química , Contaminantes Químicos del Agua/química
4.
J Environ Manage ; 366: 121891, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39047432

RESUMEN

Dual functional materials can be beneficial for simultaneous application in different fields. Herein, tubular graphitic carbon nitride (TCN) was anchored on natural diatomite (DT) by performing a simple hydrothermal-calcination method and the as-obtained composite (TCN/DT) was utilized in both photocatalytic remediation and thermal energy storage. The optimal sample, TCN/DT/3, could degrade 88.9 % of tetracycline, which was about 2.87 times than that of the pristine TCN. This could be due to extended light absorption ability, altered band structure and enhanced separation rate of photoinduced carrier. The photocatalytic efficiency remained 78.0% after fifth cycle, indicating its reusability feature. The reaction was mainly driven by superoxide radicals as well as holes and hydroxyl radicals mediated the reaction. The TCN/DT/3/Vis system showed good performance at near-neutral pH, also the system could be efficiently performed under tap water and drinking water. On the other hand, the usage of TCN/DT/3 catalyst as a framework for shape-stabilized stearic acid (SA) based composite phase change materials (PCMs) was explored. The composite PCM exhibited higher thermal energy storage capacity accompanied with improved thermal conductivity in comparison with DT/PCM composite. This study presented a novel composite materials which exhibited a synergistic effect between TCN and DT, resulting in high photocatalytic activity and effective thermal energy storage capacity.


Asunto(s)
Tierra de Diatomeas , Grafito , Energía Solar , Tierra de Diatomeas/química , Catálisis , Grafito/química , Porosidad , Compuestos Inorgánicos de Carbono/química , Compuestos de Nitrógeno/química , Contaminantes Químicos del Agua/química
5.
J Mater Chem B ; 12(24): 5974-5981, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38809058

RESUMEN

Rapid and sensitive detection of food-borne bacteria has remained challenging over the past few decades. We propose a surface-enhanced Raman scattering sensing strategy based on a novel bioinspired surface-enhanced Raman scattering substrate, which can directly detect dye molecular residues and food-borne pathogen microorganisms in the environment. The surface-enhanced Raman scattering platform consists of a natural diatomite microporous array decorated with a metal-phenolic network that enables the in situ reduction of gold nanoparticles. The as-prepared nanocomposites display excellent surface-enhanced Raman scattering activity with the lowest limit of detection and the maximum Raman enhancement factor of dye molecules up to 10-11 M and 1.18 × 107, respectively. For food-borne bacterial detection, a diatomite microporous array decorated with a metal polyphenol network and gold nanoparticle-based surface-enhanced Raman scattering analysis is capable of distinguishing the biochemical fingerprint information of Staphylococcus aureus and Escherichia coli, indicating the great potential for strain identification.


Asunto(s)
Tierra de Diatomeas , Escherichia coli , Oro , Espectrometría Raman , Staphylococcus aureus , Espectrometría Raman/métodos , Staphylococcus aureus/aislamiento & purificación , Tierra de Diatomeas/química , Escherichia coli/aislamiento & purificación , Oro/química , Nanopartículas del Metal/química , Microbiología de Alimentos , Propiedades de Superficie , Tamaño de la Partícula
6.
Biomater Adv ; 161: 213894, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38796956

RESUMEN

Engineering of scaffolds for bone regeneration is often inspired by the native extracellular matrix mimicking its composite fibrous structure. In the present study, we used low loadings of diatomite earth (DE) biosilica to improve the bone regeneration potential of gelatin electrospun fibrillar microenvironments. We explored the effect of increasing the DE content from 1 % to 3 % and 5 %, respectively, on the physico-chemical properties of the fibrous scaffolds denoted FG_DE1, FG_DE3, FG_DE5, regarding the aqueous media affinity, stability under simulated physiological conditions, morphology characteristics, and local mechanical properties at the surface. The presence of biosilica generated composite structures with lower swelling degrees and higher stiffness when compared to gelatin fibers. Increasing DE content led to higher Young modulus, while the stability of the protein matrix in PBS, at 37 °C, over 21 was significantly decreased by the presence of diatomite loadings. The best preosteoblast response was obtained for FG_DE3, with enhanced mineralization during the osteogenic differentiation when compared to the control sample without diatomite. 5 % DE in FG_DE5 proved to negatively influence cells' metabolic activity and morphology. Hence, the obtained composite microfibrillar scaffolds might find application as osteoblast-responsive materials for bone tissue engineering.


Asunto(s)
Gelatina , Osteoblastos , Ingeniería de Tejidos , Andamios del Tejido , Gelatina/química , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Andamios del Tejido/química , Ingeniería de Tejidos/métodos , Animales , Tierra de Diatomeas/química , Osteogénesis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Ratones , Regeneración Ósea/efectos de los fármacos , Línea Celular , Microambiente Celular/efectos de los fármacos , Microfibrillas/química , Microfibrillas/metabolismo , Matriz Extracelular/metabolismo , Matriz Extracelular/química , Matriz Extracelular/efectos de los fármacos
7.
Int J Biol Macromol ; 267(Pt 1): 131447, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38588843

RESUMEN

The drug encapsulation efficiency, release rate and time, sustained release, and stimulus-response of carriers are very important for drug delivery. However, these always cannot obtained for the carrier with a single component. To improve the comprehensive performance of chitosan-based carriers for 5-Fu delivery, diatomite-incorporated hydroxypropyl cellulose/chitosan (DE/HPC/CS) composite aerogel microspheres were fabricated for the release of 5-fluorouracil (5-Fu), and the release performance was regulated with the content of diatomite, pH value, and external coating material. Firstly, the 5-Fu loaded DE/HPC/CS composite aerogel microspheres and Eudragit L100 coated microspheres were prepared with cross-linking followed by freeze-drying, and characterized by SEM, EDS, FTIR, XRD, DSC, TG, and swelling. The obtained aerogel microspheres have a diameter of about 0.5 mm, the weight percentage of F and Si elements on the surface are 0.55 % and 0.78 % respectively. The glass transition temperature increased from 179 °C to 181 °C and 185 °C with the incorporation of DE and coating of Eudragit, and the equilibrium swelling percentage of DE/HPC/CS (1.5:3:2) carriers are 101.52 %, 45.27 %, 67.32 % at pH 1.2, 5.0, 7.4, respectively. Then, the effect of DE content on the drug loading efficiency of DE/HPC/CS@5-Fu was investigated, with the increase of DE content, the highest encapsulation efficiency was 82.6 %. Finally, the release behavior of DE incorporated and Eudragit L100 Coated microspheres were investigated under different pH values, and evaluated with four kinetic models. The results revealed that the release rate of 5-Fu decreased with the increase of DE content, sustained release with extending time and pH-responsive were observed for the Eudragit-coated aerogel microspheres.


Asunto(s)
Celulosa , Celulosa/análogos & derivados , Quitosano , Preparaciones de Acción Retardada , Tierra de Diatomeas , Portadores de Fármacos , Liberación de Fármacos , Fluorouracilo , Microesferas , Ácidos Polimetacrílicos , Quitosano/química , Celulosa/química , Fluorouracilo/química , Fluorouracilo/administración & dosificación , Tierra de Diatomeas/química , Ácidos Polimetacrílicos/química , Portadores de Fármacos/química , Concentración de Iones de Hidrógeno , Geles/química
8.
Int J Biol Macromol ; 266(Pt 2): 131313, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38569997

RESUMEN

In recent years, considerable attention has been given to the utilization of biomass for producing bio-based foams, such as starch-based foams. Despite their renewability and widespread availability, these foams still present certain drawbacks regarding their poor mechanical properties and flammability. To tackle these concerns, a metal ion cross-linking strategy was employed by incorporating calcium ions (Ca2+) solution into foamed starch/cellulose slurry. Followed by ambient drying, starch/cellulose composite foam was successfully fabricated with a remarkable enhancement in various properties. Specifically, compared to the control sample, the compressive strength and modulus increased by 26.2 % and 123.0 %, respectively. Additionally, the Ca2+ cross-linked starch/cellulose composite foam exhibited excellent heat resistance, water stability, and flame retardancy. The limiting oxygen index (LOI) reached 52 %, with a vertical combustion rating of V-0. Along with the addition of 2 phr diatomite, it demonstrated a significant enhancement on flame retardancy with a LOI of 65 %, although the apparent density of the composite foam was not low enough. This study indicated a green and simple method to obtain starch-based composite foams with enhanced comprehensive properties including thermal, water stability, mechanical, and flame retardancy, expanding their potential applications in areas such as building materials and rigid packaging.


Asunto(s)
Celulosa , Tierra de Diatomeas , Retardadores de Llama , Almidón , Celulosa/química , Almidón/química , Tierra de Diatomeas/química , Fuerza Compresiva , Agua/química , Calcio/química
9.
Environ Sci Pollut Res Int ; 31(22): 32003-32015, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38642231

RESUMEN

The Li4SiO4 seems to be an excellent sorbent for CO2 capture at post-combustion. Our work contributes to understanding the effect of the natural Algerian diatomite as a source of SiO2 in the synthesis of Li4SiO4 for CO2 capture at high temperature. For this purpose, we use various molar % (stoichiometric and excess) of calcined natural diatomite and pure SiO2. To select the best composition, CO2 sorption isotherms at 500 °C on the prepared Li4SiO4 are obtained using TGA measurements under various flows of CO2 in N2. The sorbent having 10% molar SiO2 in diatomite (10%ND-LS) exhibits the best CO2 uptake, probably due to various factors such as the content of the different secondary phases. A comparative study was performed at 400 to 500 °C on this selected 10%ND-LS and those with stoichiometric composition obtained with diatomite and pure SiO2. The obtained isotherms show the endothermic character of CO2 sorption. In addition, the evolution of isosteric heat highlights the nature of the involved CO2/Li4SiO4 interactions, by considering the double-shell mechanism. Finally, the experimental sorption isotherms are confronted with some well-known adsorption models to explain the phenomenon occurring over our prepared sorbents. Freundlich and Jensen-Seaton models present a better correlation with the experimental results.


Asunto(s)
Dióxido de Carbono , Tierra de Diatomeas , Tierra de Diatomeas/química , Adsorción , Dióxido de Carbono/química , Calor , Dióxido de Silicio/química
10.
Int J Biol Macromol ; 266(Pt 1): 131142, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38537846

RESUMEN

This study addresses the challenge of platinum-group metal scarcity by exploring the adsorption of these metals from industrial wastewater. An inexpensive adsorbent with selective platinum-group metal adsorption capacity, named chitosan/citric acid@diatomaceous earth-sugarcane bagasse (CTS/CA@DE-SBS), was newly synthesized. The material features a double coating of chitosan and diatomite on bagasse biochar, and it exhibits an excellent adsorption performance for platinum-group metals due to the synergistic effects of the biochar and chitosan-diatomaceous earth intercross-linked coatings. CTS/CA@DE-SBS achieved an 81 % adsorption efficiency and a static saturated adsorption capacity of 217 mg/g for Pt (IV) in water. Notably, the material exhibited selective adsorption properties for platinum-group metals dissolved in diverse aqueous solutions. The potential for the secondary recovery of platinum-group metals in complex aqueous bodies further underscores the significance of this adsorbent. In conclusion, this research introduces a promising solution for platinum-group metal shortages, offering a cost-effective and selective adsorbent with potential applications in the secondary recovery of these metals from industrial wastewater.


Asunto(s)
Celulosa , Carbón Orgánico , Quitosano , Platino (Metal) , Aguas Residuales , Contaminantes Químicos del Agua , Purificación del Agua , Quitosano/química , Adsorción , Aguas Residuales/química , Celulosa/química , Carbón Orgánico/química , Contaminantes Químicos del Agua/aislamiento & purificación , Contaminantes Químicos del Agua/química , Platino (Metal)/química , Purificación del Agua/métodos , Tierra de Diatomeas/química , Metales/química
11.
J Sci Food Agric ; 104(11): 6563-6572, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-38520271

RESUMEN

BACKGROUND: Fructo-oligosaccharide (FOS) belongs to the group of short inulin-type fructans and is one of the most important non-digestible bifid-oligosaccharides capable of biotransforming sucrose using fructosyltransferase (FTase). However, there are no immobilized FTase products that can be successfully used industrially. In this study, diatomite was subjected to extrusion, sintering and granulation to form diatomaceous earth particles that were further modified via chitosan aminomethylation for modification. FTase derived from Aspergillus oryzae was successfully immobilized on the modified support via covalent binding. RESULTS: The immobilized enzyme activity was 503 IU g-1 at an enzyme concentration of 0.6 mg mL-1, immobilization pH of 7.0 and contact time of 3 h. Additionally, the immobilization yield was 56.91%. Notably, the immobilized enzyme was more stable under acidic conditions. Moreover, the half-life of the immobilized enzyme was 20.80 and 10.96 times as long as that of the free enzyme at 45 and 60 °C, respectively. The results show good reusability, as evidenced by the 84.77% retention of original enzyme activity after eight cycles. Additionally, the column transit time of the substrate was 35.56 min when the immobilized enzyme was applied in a packed-bed reactor. Furthermore, a consistently high FOS production yield of 60.68% was achieved and maintained over the 15-day monitoring period. CONCLUSIONS: Our results suggest that immobilized FTase is a viable candidate for continuous FOS production on an industrial scale. © 2024 Society of Chemical Industry.


Asunto(s)
Quitosano , Tierra de Diatomeas , Estabilidad de Enzimas , Enzimas Inmovilizadas , Hexosiltransferasas , Oligosacáridos , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Hexosiltransferasas/metabolismo , Hexosiltransferasas/química , Quitosano/química , Quitosano/metabolismo , Oligosacáridos/química , Oligosacáridos/metabolismo , Tierra de Diatomeas/química , Concentración de Iones de Hidrógeno , Aspergillus oryzae/enzimología , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Cinética , Proteínas Bacterianas
12.
Molecules ; 28(24)2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38138471

RESUMEN

Heparin, a highly sulfated glycosaminoglycan, is a naturally occurring anticoagulant that plays a vital role in various physiological processes. The remarkable structural complexity of heparin, consisting of repeating disaccharide units, makes it a crucial molecule for the development of commercial drugs in the pharmaceutical industry. Over the past few decades, significant progress has been made in the development of cost-effective adsorbents specifically designed for the adsorption of heparin from porcine intestinal mucosa. This advancement has been driven by the need for efficient and scalable methods to extract heparin from natural sources. In this study, we investigated the use of cationic ammonium-functionalized diatomaceous earth, featuring enhanced porosity, larger surface area, and higher thermal stability, to maximize the isolated heparin recovery. Our results showed that the higher cationic density and less bulky quaternary modified diatomaceous earth (QDADE) could adsorb up to 16.3 mg·g-1 (31%) of heparin from the real mucosa samples. Additionally, we explored the conditions of the adsorbent surface for recovery of the heparin molecule and optimized various factors, such as temperature and pH, to optimize the heparin uptake. This is the introductory account of the implementation of modified diatomaceous earth with quaternary amines for heparin capture.


Asunto(s)
Tierra de Diatomeas , Heparina , Animales , Porcinos , Tierra de Diatomeas/química , Anticoagulantes , Temperatura , Mucosa Intestinal
13.
Chemosphere ; 330: 138725, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37084900

RESUMEN

A novel nanofiltration membrane was developed by entrapping a layer of modified diatomaceous earth between two layers of electrospun polysulfone (E-PSf) nanofibers. The diatomaceous earth particles and the fabricated membrane were characterized using FTIR, SEM, EDS, zeta potential, and water contact angle techniques. The static adsorption and dynamic separation of pristine E-PSF and sandwich-like membranes for methylene blue (MB) with/without salt were investigated under different operating conditions. The Langmuir model suited the MB adsorption isotherm data with a linear regression correlation coefficient (R2) >0.9955. As pH increased, both flux and MB rejection of the sandwich-like membrane improved by up to 183.8 LMH and 99.7%, respectively, when operated under gravity. The water flux of the sandwich-like membrane was sharply increased by increasing the pressure up to 19,518.2 LMH at 4.0 bar. However, this came at the expense of MB rejection (10.93%) and reduced its practical impact. At a high salt concentration, the sandwich-like membrane also indicated remarkable dye/salt separation with a higher permeation of salt (<0.2% NaCl rejection) and MB rejection (>99%). The performance of the regenerated diatomaceous material and membrane was maintained during five cycles of operation compared to that of the original ones.


Asunto(s)
Tierra de Diatomeas , Cloruro de Sodio , Cloruro de Sodio/química , Tierra de Diatomeas/química , Agua , Adsorción , Azul de Metileno
14.
Biotechnol Bioeng ; 120(7): 1882-1890, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36929487

RESUMEN

A number of studies have demonstrated that depth filtration can provide significant adsorptive removal of host cell proteins (HCP), but there is still considerable uncertainty regarding the underlying factors controlling HCP binding. This study compared the binding characteristics of two fine grade depth filters, the X0SP (polyacrylic fiber with a synthetic silica filter aid) and X0HC (cellulose fibers with diatomaceous earth (DE) as a filter aid), using a series of model proteins with well-defined physical characteristics. Protein binding to the X0SP filter was dominated by electrostatic interactions with greatest capacity for positively-charged proteins. In contrast, the X0HC filter showed greater binding of more hydrophobic proteins although electrostatic interactions also played a role. In addition, ovotransferrin showed unusually high binding capacity to the X0HC, likely due to interactions with metals in the DE. Scanning Electron Microscopy with Energy Dispersive Spectroscopy was used to obtain additional understanding of the binding behavior. These results provide important insights into the physical phenomena governing HCP binding to both fully synthetic and natural (cellulose + DE) depth filters.


Asunto(s)
Tierra de Diatomeas , Dióxido de Silicio , Tierra de Diatomeas/química , Filtración/métodos , Adsorción , Proteínas/química
15.
J Environ Manage ; 317: 115380, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35636115

RESUMEN

The oxidization of As(III) to As(V) is necessary for both the detoxification of arsenic and the removal of arsenic by solidification. In order to achieve high efficiency and low cost As(III) oxidation, a novel process of catalytic aerial oxidation of As(III) is proposed, using air as oxidant and Mn-loaded diatomite as a catalyst. Through systematic characterization of the reaction products, the catalytic oxidation reaction law of Mn-loaded diatomite for As(III) was found out, and its reaction mechanism was revealed. Results show that Mn-loaded diatomite achieved a good catalytic effect for aerial oxidation of As(III) and maintained high performance over multiple cycles of reuse, which was directly related to the structure of diatomite and the behavior of manganese. Under the conditions of a catalyst concentration of 20 g/L, an air flow rate of 0.3 m3/h, a reaction temperature of 50 °C and an initial pH of 12.6, 96.04% As(III) oxidation was achieved after 3 h. Furthermore, the efficiency of As(III) oxidation did not change significantly after ten cycles of reuse. XPS analysis of the reaction products confirmed that the surface of the catalyst was rich in Mn(III), Mn(IV) and adsorbed oxygen(O-H), which was the fundamental reason for the excellent performance of Mn-loaded diatomite in the catalytic oxidation of As(III).


Asunto(s)
Arsénico , Compuestos de Manganeso , Arsénico/química , Tierra de Diatomeas/química , Compuestos de Manganeso/química , Oxidación-Reducción , Óxidos/química
16.
Molecules ; 26(24)2021 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-34946567

RESUMEN

Nowadays, we are tackling various issues related to the overuse of synthetic insecticides. Growing concerns about biodiversity, animal and human welfare, and food security are pushing agriculture toward a more sustainable approach, and research is moving in this direction, looking for environmentally friendly alternatives to be adopted in Integrated Pest Management (IPM) protocols. In this regard, inert dusts, especially diatomaceous earths (DEs), hold a significant promise to prevent and control a wide range of arthropod pests. DEs are a type of naturally occurring soft siliceous sedimentary rock, consisting of the fossilized exoskeleton of unicellular algae, which are called diatoms. Mainly adopted for the control of stored product pests, DEs have found also their use against some household insects living in a dry environment, such as bed bugs, or insects of agricultural interest. In this article, we reported a comprehensive review of the use of DEs against different arthropod pest taxa, such as Acarina, Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, Ixodida, Lepidoptera, when applied either alone or in combination with other techniques. The mechanisms of action of DEs, their real-world applications, and challenges related to their adoption in IPM programs are critically reported.


Asunto(s)
Artrópodos/efectos de los fármacos , Tierra de Diatomeas/farmacología , Control de Insectos , Insecticidas/farmacología , Animales , Tierra de Diatomeas/química , Insecticidas/química
17.
Int J Mol Sci ; 22(19)2021 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-34639096

RESUMEN

Inorganic diatomite nanoparticles (DNPs) have gained increasing interest as drug delivery systems due to their porous structure, long half-life, thermal and chemical stability. Gold nanoparticles (AuNPs) provide DNPs with intriguing optical features that can be engineered and optimized for sensing and drug delivery applications. In this work, we combine DNPs with gelatin stabilized AuNPs for the development of an optical platform for Galunisertib delivery. To improve the DNP loading capacity, the hybrid platform is capped with gelatin shells of increasing thicknesses. Here, for the first time, full optical modeling of the hybrid system is proposed to monitor both the gelatin generation, degradation, and consequent Galunisertib release by simple spectroscopic measurements. Indeed, the shell thickness is optically estimated as a function of the polymer concentration by exploiting the localized surface plasmon resonance shifts of AuNPs. We simultaneously prove the enhancement of the drug loading capacity of DNPs and that the theoretical modeling represents an efficient predictive tool to design polymer-coated nanocarriers.


Asunto(s)
Tierra de Diatomeas/química , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Gelatina/química , Oro/química , Nanopartículas del Metal/química , Pirazoles/metabolismo , Quinolinas/metabolismo , Porosidad
18.
Molecules ; 26(17)2021 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-34500641

RESUMEN

A novel diatomite-supported zeolitic imidazolate framework-8 sorbent (ZIF-8@Dt-COOH) was in situ fabricated and developed for solid-phase extraction of three benzodiazepines (triazolam, midazolam and diazepam) in urine followed by high-performance liquid chromatography. ZIF-8@Dt-COOH was easily prepared by coating ZIF-8 on the surface of Dt-COOH and characterized by Fourier transform infrared spectra, X-ray powder diffractometry and scanning electron microscopy. Compared with bare Dt-COOH, the extraction efficiency of ZIF-8@Dt-COOH for the target was significantly increased from 20.1-39.0% to 100%. Main extraction parameters, including ionic strength and pH of solution, loading volume, washing solution, elution solvent and elution volume, were optimized in detail. Under optimum conditions, the developed method gave linearity of three BZDs in 2-500 ng/mL (r ≥ 0.9995). Limits of detection (S/N = 3), and limits of quantification (S/N = 10) were 0.3-0.4 ng/mL and 1.0-1.3 ng/mL, respectively. In addition, the average recoveries at three spiked levels (5, 10 and 20 ng/mL) varied from 80.0% to 98.7%, with the intra-day and inter-day precisions of 1.4-5.2% and 1.5-8.2%, respectively. The proposed method provided an effective purification performance and gave the enrichment factors of 24.0-29.6. The proposed method was successfully employed for the accurate and sensitive determination of benzodiazepines in urine.


Asunto(s)
Benzodiazepinas/orina , Tierra de Diatomeas/química , Orina/química , Zeolitas/química , Cromatografía Líquida de Alta Presión/métodos , Humanos , Límite de Detección , Extracción en Fase Sólida/métodos , Soluciones/química , Solventes/química
19.
Carbohydr Polym ; 271: 118424, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34364565

RESUMEN

Chitosan films lack various important physicochemical properties and need to be supplemented with reinforcing agents to bridge the gap. Herein, we have produced chitosan composite films supplemented with copolymerized (with polyacrylonitrile monomers) cellulose nanofibers and diatomite nanocomposite at different concentrations. The incorporation of CNFs and diatomite enhanced the physicochemical properties of the films. The mechanical characteristics and hydrophobicity of the films were observed to be improved after incorporating the copolymerized CNFs/diatomite composite at different concentrations (CNFs: 1%, 2% and 5%; diatomite: 10% and 30%). The antioxidant activity gradually increased with an increasing concentration (1-5% and 10-30%) of copolymerized CNFs/diatomite composite in the chitosan matrix. Moreover, the water solubility decreased from 30% for chitosan control film (CH-0) to 21.06% for films containing 30% diatomite and 5% CNFs (CNFs-D30-5). The scanning electron micrographs showed an overall uniform distribution of copolymerized CNFs/diatomite composite in the chitosan matrix with punctual agglomerations.


Asunto(s)
Celulosa/química , Quitosano/química , Tierra de Diatomeas/química , Membranas Artificiales , Nanocompuestos/química , Nanofibras/química , Antioxidantes/química , Embalaje de Alimentos , Ensayo de Materiales , Óptica y Fotónica , Solubilidad , Resistencia a la Tracción , Temperatura de Transición
20.
Bioprocess Biosyst Eng ; 44(8): 1781-1792, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33830378

RESUMEN

To improve the operational stability of glucose isomerase in E. coli TEGI-W139F/V186T, the immobilized cells were prepared with modified diatomite as a carrier and 74.1% activity of free cells was recovered after immobilization. Results showed that the immobilized cells still retained 86.2% of the initial transformational activity after intermittent reused 40 cycles and the yield of D-fructose reached above 42% yield at 60 °C. Moreover, the immobilized cells were employed in the continuous production of High Fructose Corn Syrup (HFCS) in a recirculating packed bed reactor for 603 h at a constant flow rate. It showed that the immobilized cells exhibited good operational stability and the yield of D-fructose retained above 42% within 603 h. The space-time yield of high fructose corn syrup reached 3.84 kg L-1 day-1. The investigation provided an efficient immobilization method for recombinant cells expressing glucose isomerase with higher stability, and the immobilized cells are a promising biocatalyst for HFCS production.


Asunto(s)
Isomerasas Aldosa-Cetosa/química , Tierra de Diatomeas/química , Escherichia coli/metabolismo , Jarabe de Maíz Alto en Fructosa/química , Proteínas Recombinantes/química , Proteínas Bacterianas , Reactores Biológicos , Cobalto/química , Enzimas Inmovilizadas , Fructosa/química , Glucosa , Concentración de Iones de Hidrógeno , Iones , Magnesio/química , Microscopía Electrónica de Rastreo , Temperatura
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