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1.
Sci Total Environ ; 900: 165823, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37517719

RESUMEN

The method of soil improvement by calcium phosphate precipitation is a novel, environmentally friendly, and non-toxic technique. Such technology provides advantages over ureolytic induced calcite precipitation (UICP), the most popular and widely used method in the field of geotechnical engineering. In this paper, an investigation of the consolidation of fine and coarse sand samples by enzyme induced calcium phosphate precipitation (EICPP) was carried out. Tuna bones were used as an alternative source of calcium and phosphorus ions, as one of the most popular fish species in Japan and the main source of food industry waste. Unconfined compressive strength (UCS) of the samples after 21 days of daily injection of the solution showed an increase in strength up to 6,05 MPa in fine and up to 4,3 MPa in coarse sand samples. X-ray powder diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (SEM-EDS) analysis were performed to investigate the nature and type of deposition. Analyses confirmed that deposition is composed of brushite with needle-like crystals in the case of Toyoura sand and flower-like crystals in the case of Mikawa sand. SEM-EDS showed a presence of both, calcium, and phosphorus in the precipitate, indicating the presence of calcium phosphate compounds (CPCs). This study reveals that tuna bones are a rich source of calcium and phosphorus for EICPP, which results in a strengthening of silicate soil up to 3.4-6.05 MPa and is able to reduce ammonia emissions by 85.7 % - 97.5 % compared to UICP.


Asunto(s)
Calcio , Suelo , Calcio/análisis , Arena , Microscopía Electrónica de Rastreo , Fosfatos de Calcio/química , Compuestos de Calcio/química , Carbonato de Calcio/química , Fósforo/análisis
2.
J Sci Food Agric ; 102(2): 740-749, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34173233

RESUMEN

BACKGROUND: The pH adjustment of acidic red soils with lime materials is beneficial for the reduction of phosphorus (P) fixation. However, the reasons for varying levels of P activation after adding different lime materials have not been fully investigated. Therefore, this study examined changes in soil labile P and P forms after phosphate application to calcium carbonate (CaCO3 ) and dolomite amended red soil during a 120-day incubation period. Also change of P sorption properties in the amended soil samples from day 120 were examined through a sorption-desorption experiment. RESULTS: The increase of soil H2 O-P and NaHCO3 -P in the CaCO3 and dolomite amended soil treatments was mainly ascribed to the decline of the NaOH-P. However, when compared with the control treatment after 120 days, soil Olsen-P significantly increased by 34% and 66% in the CaCO3 and dolomite treatments. The Hedley P fractionation results demonstrated that the CaCO3 application caused a notable increase of HCl-P (stable Ca-P), which was 88.4% higher than that in the dolomite treatment. However, the formation of stable P was strongly suppressed in the dolomite treatment due to the presence of magnesium (Mg), which was identified by the negative relationship between M3-Mg and HCl-P. In line with these findings, P sorption-desorption work showed weaker P binding energy in the dolomite treatment relative to the CaCO3 treatment. CONCLUSION: In terms of increasing P availability in red soil, this study suggests that dolomite should be used to substitute CaCO3 in order to reduce the soil P fixation. © 2021 Society of Chemical Industry.


Asunto(s)
Carbonato de Calcio/química , Magnesio/química , Fósforo/química , Suelo/química , Adsorción , Compuestos de Calcio/química , Fertilizantes/análisis , Concentración de Iones de Hidrógeno , Óxidos/química , Fosfatos/química
3.
J Microsc ; 286(2): 120-125, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34664277

RESUMEN

Carbonated wollastonite clinker (CS) may be suitable as supplementary cementitious material (SCM) for mortar and concrete. The microstructure of unground CS clinker, carbonated CS slurry and a mortar blended with carbonated CS are investigated by scanning electron microscopy. Additionally, a reference mortar with pure Portland cement and one with a cement replacement level of 30 mass-% by carbonated CS are produced to assess its contribution to compressive strength development. The calcium silicates are decalcified during carbonation resulting in CaCO3 and amorphous SiO2 . The latter reacts when used as SCM in mortar influencing the Ca/Si ratio of calcium-silicate-hydrate and contributing to compressive strength development.


Asunto(s)
Calcio , Dióxido de Silicio , Compuestos de Calcio/química , Silicatos/química
4.
Molecules ; 26(22)2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34833924

RESUMEN

Dental caries results from the bacterial pathogen Streptococcus mutans (S. mutans) and is the maximum critical reason for caries formation. Consequently, the present study aims to evaluate the antibacterial activity of a newly synthesized nanoantibiotic-Biodentine formulation. The silver nanoparticles (ROE-AgNPs) were biosynthesized from the usage of Rosmarinus officinalis L. extract (ROE) and conjugated with cefuroxime to form Cefuroxime-ROE-AgNPs. Using Biodentine™ (BIOD), five groups of dental materials were prepared, in which Group A included conventional BIOD, Group B included BIOD with ROE-AgNPs, Groups C and D included BIOD with Cefuroxime-ROE-AgNPs at concentrations of 0.5% and 1.5% cefuroxime, respectively, and Group E included BIOD with 1.5% cefuroxime. The synthesized ROE-AgNPs or Cefuroxime-ROE-AgNPs were characterized for conjugating efficiency, morphology, particle size, and in vitro release. Minimum inhibitory concentration (MIC) of the cefuroxime, ROE-AgNPs, and Cefuroxime-ROE-AgNPs were additionally evaluated against cefuroxime resistant S. mutans, which furthered antibacterial efficacy of the five groups of dental materials. The UV-Visible spectrum showed the ROE-AgNPs or Cefuroxime-ROE-AgNPs peaks and their formation displayed through transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern, and Fourier transforms infrared (FTIR) analysis. The end result of Cefuroxime-ROE-AgNPs showed conjugating efficiency up to 79%. Cefuroxime-ROE-AgNPs displayed the highest antibacterial efficacy against S. mutans as compared to cefuroxime or ROE-AgNPs alone. Moreover, the MIC of ROE-AgNPs and Cefuroxime-ROE-AgNPs was detected against S. mutans to be 25 and 8.5 µg/mL, respectively. Consequently, Cefuroxime-ROE-AgNPs displayed that a decrease in the MIC reached to more than three-fold less than MIC of ROE-AgNPs on the tested strain. Moreover, Cefuroxime-ROE-AgNPs/BIOD was employed as a novel dental material that showed maximum antimicrobial activity. Groups C and D of novel materials showed inhibitory zones of 19 and 26 mm, respectively, against S. mutans and showed high antimicrobial rates of 85.78% and 91.17%, respectively. These data reinforce the utility of conjugating cefuroxime with ROE-AgNPs to retrieve its efficiency against resistant S. mutant. Moreover, the nanoantibiotic delivered an advantageous antibacterial effect to BIOD, and this may open the door for future conjugation therapy of dental materials against bacteria that cause dental caries.


Asunto(s)
Compuestos de Calcio/química , Compuestos de Calcio/farmacología , Cefuroxima/química , Cefuroxima/farmacología , Nanopartículas del Metal/química , Silicatos/química , Silicatos/farmacología , Plata/química , Streptococcus mutans/efectos de los fármacos , Antibacterianos/química , Antibacterianos/farmacología , Caries Dental/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana/métodos , Tamaño de la Partícula , Extractos Vegetales/química , Extractos Vegetales/farmacología
5.
Pak J Biol Sci ; 24(8): 847-857, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34486352

RESUMEN

<b>Background and Objective:</b> Adequate yield improvement in groundnut may not be achieved in acid sand Ultisol through the application of mineral phosphorus alone, however, a combined application of lime and phosphorus fertilizer may be a better management option in such soils. Hence, this study evaluated the effects of four levels of lime (0, 2.0, 4.0 and 8.0 t ha<sup>1</sup>) and four phosphorus (P) levels (0, 25, 50 and 75 kg ha<sup>1</sup>) on the performance of groundnut (<i>Arachis hypogaea </i>L.) in the humid rainforest of South Eastern Nigeria. <b>Materials and Methods:</b> The study was a factorial experiment laid out in a Randomized Complete Block Design (RCBD) and consisted of sixteen treatment combinations replicated three times each. <b>Results:</b> The result obtained showed that the application of phosphorus fertilizer and lime had a significant (p<0.05) effect on plant height, number of leaves per plant, number of branches per plant, 75 kg ha<sup>1</sup> P and 8.0 t ha<sup>1</sup> lime resulted in the highest growth parameter. Similarly, 75 kg ha<sup>1</sup> P and 8.0 t ha<sup>1</sup> lime significantly improved the number of pods per plant 30.67, pod yield 3.58 t ha<sup>1</sup>, biomass yield of 4.68 t ha<sup>1</sup>, seed yield of 2.1 t ha<sup>1</sup> and 100 seed weight of 44.58 g, seed yield of groundnut while curtailing the number of unfilled pods 2.33. <b>Conclusion:</b> Application of phosphorus and lime at 75 kg ha<sup>1</sup> P and 8.0 t ha<sup>1</sup> lime is a beneficial agronomic practice that could enhance the productivity of groundnut in the Calabar rainforest zone of Cross River State.


Asunto(s)
Arachis/química , Compuestos de Calcio/química , Óxidos/química , Fósforo/química , Biomasa , Calcio/química , Cationes , Productos Agrícolas/crecimiento & desarrollo , Fertilizantes , Concentración de Iones de Hidrógeno , Magnesio/química , Nigeria , Hojas de la Planta/crecimiento & desarrollo , Potasio/química , Arena , Sodio/química , Suelo
6.
J Oleo Sci ; 70(9): 1335-1341, 2021 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-34373402

RESUMEN

To overcome the key challenges associated with cement dust, such as inhalable size, toxic ions, and the existence of large quantities of useless materials, researchers investigated an innovative and unusual conversion of toxic cement dust into Mayenite nanoparticles. Mayenite is a natural structure that can be used as a filler in a variety of industrial applications. The formation of Mayenite nanoparticles was achieved through a thermal reaction at 1000°C for 2 h between cement dust and aluminum oxide. Different techniques were used to characterize the synthesized Mayenite nanoparticles, revealing the formation of the target phase as well as the reduction of toxic ions present in cement dust. According to Scherrer's equation, the crystallite size of bypass and synthesized Mayenite nanoparticles is 45 and 30 nm, respectively. Also, with the aid of TEM analysis, the particle size distribution of the produced Mayenite nanoparticles was found to be 27±7 nm. The toxic ions, especially chlorides and sulphates, were reduced by 86% and 50%, respectively, according to X-ray fluorescence results. These findings are important for the future use of Mayenite, 12CaO.7Al2O3 (C12A7), nanoparticles formed from toxic cement dust recycling.


Asunto(s)
Compuestos de Aluminio/química , Óxido de Aluminio/síntesis química , Compuestos de Calcio/química , Polvo , Minerales/síntesis química , Óxido de Aluminio/química , Cloruros , Calor , Minerales/química , Nanopartículas , Tamaño de la Partícula , Reciclaje , Sulfatos
7.
J Oleo Sci ; 70(6): 769-775, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33967170

RESUMEN

We previously reported that fluid soybean lecithin (SL) undergoes heat deterioration by the newly reported pseudo-Maillard rearrangement reaction. To inhibit heat deterioration, SLs were treated with metal silicates, such as magnesium silicate and calcium silicate. When soybean fatty acid was added to SL before treatment with calcium silicate, the color index after heating improved significantly as the acid value increased from 10 to 35 mg KOH/g. To elucidate the role of soybean fatty acid, calcium silicate treatment was carried out by adding several fatty acids to SL. Although saturated fatty acids had no effect on the heat deterioration of SL, unsaturated fatty acids were significantly more effective at inhibiting heat deterioration. Furthermore, for unsaturated fatty acids, it was confirmed that the calcium concentration increased in SL. Based on these results, several fatty acid metal salts were added to confirm whether heat deterioration while heating SL could be inhibited. It was observed that the heat deterioration of SL could be inhibited with fatty acid metal salts, regardless of whether the fatty acids were saturated or unsaturated and whether the metal was monovalent, divalent, or trivalent. Therefore, in this study, we clarified that the heat deterioration of SL could be inhibited by adding fatty acid metal salts to SL. Among sodium stearate, calcium stearate, magnesium stearate, barium stearate, and aluminum tristearate, the divalent fatty acid metal salts had a stronger inhibitory effect on heat deterioration than the monovalent and trivalent salts.


Asunto(s)
Ácidos Grasos/química , Lecitinas/química , Reacción de Maillard/efectos de los fármacos , Compuestos de Calcio/química , Calor , Metales/química , Silicatos/química , Glycine max/química
8.
Carbohydr Polym ; 259: 117710, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33673989

RESUMEN

Harmful algal blooms induce severe environmental problems. It is challenging to remove algae by the current available treatments involving complicate process and costly instruments. Here, we developed a CaO2@PEG-loaded water-soluble self-branched chitosan (CP-SBC) system, which can remove algae from water in one-step without additional instrumentation. This approach utilizes a novel flocculant (self-branched chitosan) integrated with flotation function (induced by CaO2@PEG). CP-SBC exhibited better flocculation performance than commercial flocculants, which is attributed to the enhanced bridging and sweeping effect of branched chitosan. CP-SBC demonstrated outstanding biocompatibility, which was verified by zebrafish test and algae activity test. CaO2@PEG-loaded self-branched chitosan can serve as an "Air flotation system" to spontaneous float the flocs after flocculation by sustainably released O2. Furthermore, CP-SBC can improve water quality through minimizing dissolved oxygen depletion and reducing total phosphorus concentrations.


Asunto(s)
Quitosano/química , Floraciones de Algas Nocivas/fisiología , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Compuestos de Calcio/química , Floculación/efectos de los fármacos , Floraciones de Algas Nocivas/efectos de los fármacos , Cinética , Larva/efectos de los fármacos , Óxidos/química , Oxígeno/química , Fósforo/química , Polietilenglicoles/química , Porosidad , Pez Cebra/crecimiento & desarrollo , Pez Cebra/fisiología
9.
Sci Rep ; 11(1): 99, 2021 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-33420110

RESUMEN

Calotropis gigantea (C. gigantea) extract with an ecofriendly nanotechnology approach could provide promising antimicrobial activity against skin pathogens. This study investigates the antimicrobial capability of green synthesized binary ZnO-CuO nanocomposites from C. gigantea against non-MDR (Staphylococcus aureus and Escherichia coli) and MDR (Klebsiella pneumoniae, Pseudomonas aeruginosa and methicillin-resistant S. aureus) skin pathogens. Scanning electron microscopy and transmission electron microscopy revealed the size and shape of B3Z1C sample. Results of X-ray powder diffraction, energy-dispersive spectroscopy, FTIR and UV-Vis spectroscopy analyses confirmed the presence of mixed nanoparticles (i.e., zinc oxide, copper oxide, carbon and calcium) and the stabilising phytochemical agents of plant (i.e., phenol and carbonyl). Antimicrobial results showed that carbon and calcium decorated binary ZnO-CuO nanocomposites with compositions of 75 wt% of ZnO and 25 wt% CuO (B3Z1C) was a strong bactericidal agent with the MBC/MIC ratio of ≤ 4 and ≤ 2 for non-MDR and MDR pathogens, respectively. A significant non-MDR zone of inhibitions were observed for BZC by Kirby-Bauer disc-diffusion test. Further time-kill observation revealed significant fourfold reduction in non-MDR pathogen viable count after 12 h study period. Further molecular studies are needed to explain the biocidal mechanism underlying B3Z1C potential.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Compuestos de Calcio/química , Compuestos de Calcio/farmacología , Calotropis/química , Óxidos/química , Óxidos/farmacología , Extractos Vegetales/farmacología , Óxido de Zinc/química , Óxido de Zinc/farmacología , Composición de Medicamentos , Evaluación Preclínica de Medicamentos , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Tecnología Química Verde , Humanos , Nanocompuestos/química , Extractos Vegetales/química , Enfermedades de la Piel/tratamiento farmacológico , Enfermedades de la Piel/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo
10.
Environ Geochem Health ; 43(7): 2679-2697, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32918158

RESUMEN

To evaluate the potential of sepiolite-based materials to resolve environmental pollution problems, a study is needed which looks at the whole life cycle of material application, including the residual value of material classified as waste from the exploitation of sepiolite deposits in the region or from its processing and purification. This would also maximize value from the exploitation process and provide new potential for local waste management. We review the geographical distribution of sepiolite, its application in the treatment of potentially toxic elements in soil and across the wider landscape, an assessment of modification and compositional variation of sepiolite-based applications within site remediation and wastewater treatment. The potential of sepiolite-based technologies is widespread and a number of processes utilize sepiolite-derived materials. Along with its intrinsic characteristics, both the long-term durability and the cost-effectiveness of the application need to be considered, making it possible to design ready-to-use products with good market acceptance. From a critical analysis of the literature, the most frequently associated terms associated with sepiolite powder are the use of lime and bentonite, while fly ash ranked in the top ten of the most frequently used material with sepiolite. These add improved performance for the inclusion as a soil or wastewater treatment options, alone or applied in combination with other treatment methods. This approach needs an integrated assessment to establish economic viability and environmental performance. Applications are not commonly evaluated from a cost-benefit perspective, in particular in relation to case studies within geographical regions hosting primary sepiolite deposits and wastes that have the potential for beneficial reuse.


Asunto(s)
Contaminación Ambiental/análisis , Restauración y Remediación Ambiental/métodos , Silicatos de Magnesio/química , Contaminantes del Suelo/análisis , Bentonita/química , Compuestos de Calcio/química , Ceniza del Carbón/química , Óxidos/química , Suelo/química , Administración de Residuos , Purificación del Agua
11.
Sci Rep ; 10(1): 17873, 2020 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-33087729

RESUMEN

Concrete can be harmful to the environment due to its high energy consumption and CO2 emission and also has a potential crack formation, which can promote a drop in its strength. Therefore, concrete is considered as a non-sustainable material. The mechanisms by which bacterial oxidation of organic carbon can precipitate calcite that may fill the voids and cracks on cement-based materials have been extensively investigated to prevent and heal the micro-cracks formation. Hence, this study focused on utilizing a new alkaliphilic bacterial strain indigenous to an Indonesian site, Lysinibacillus sphaericus strain SKC/VA-1, incorporated with calcium lactate pentahydrate, as a low-cost calcium source, with various bacterial inoculum concentrations. The bacterium was employed in this study due to its ability to adapt to basic pH, thus improving the physical properties and rejuvenating the micro-cracks. Experimentally, the addition of calcium lactate pentahydrate slightly affected the mortar properties. Likewise, bacteria-incorporated mortar exhibited an enhancement in the physical properties of mortar. The highest improvement of mechanical properties (an increase of 45% and 36% for compressive and indirect tensile strength, respectively) was achieved by the addition of calcium lactate pentahydrate incorporated with 10% v/v bacterial inoculum [about 7 × 107 CFU/ml (colony-forming unit/ml)]. The self-healing took place more rapidly on bacterial mortar supplemented with calcium lactate pentahydrate than on the control specimen. XRD analysis demonstrated that the mineralogical composition of self-healing precipitates was primarily dominated by calcite (CaCO3), indicating the capacity of L. sphaericus strain SKC/VA-1 to precipitate calcite through organic carbon oxidation for self-healing the artificial crack on the mortar. To our knowledge, this is the first report on the potential utilization of the bacterium L. sphaericus incorporated with calcium lactate pentahydrate to increase the mortar properties, including its self-healing ability. However, further study with the water-cement ratio variation is required to investigate the possibility of using L. sphaericus and calcium lactate pentahydrate as an alternative method rather than reducing the water-cement ratio to enhance the mortar properties.


Asunto(s)
Bacillaceae/metabolismo , Carbonato de Calcio/química , Materiales de Construcción/microbiología , Fenómenos Biomecánicos/fisiología , Calcio/metabolismo , Compuestos de Calcio/química , Fuerza Compresiva , Indonesia , Lactatos/química , Resistencia a la Tracción
12.
Molecules ; 25(20)2020 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-33081238

RESUMEN

Temperature-dependent Raman scattering and differential scanning calorimetry were applied to the study of the hybrid organic-inorganic azide-perovskite [(CH3)4N][Cd(N3)3], a compound with multiple structural phase transitions as a function of temperature. A significant entropy variation was observed associated to such phase transitions, |∆S| ~ 62.09 J·kg-1 K-1, together with both a positive high barocaloric (BC) coefficient |δTt/δP| ~ 12.39 K kbar-1 and an inverse barocaloric (BC) coefficient |δTt/δP| ~ -6.52 kbar-1, features that render this compound interesting for barocaloric applications. As for the obtained Raman spectra, they revealed that molecular vibrations associated to the NC4, N3- and CH3 molecular groups exhibit clear anomalies during the phase transitions, which include splits and discontinuity in the phonon wavenumber and lifetime. Furthermore, variation of the TMA+ and N3- modes with temperature revealed that while some modes follow the conventional red shift upon heating, others exhibit an unconventional blue shift, a result which was related to the weakening of the intermolecular interactions between the TMA (tetramethylammonium) cations and the azide ligands and the concomitant strengthening of the intramolecular bondings. Therefore, these studies show that Raman spectroscopy is a powerful tool to gain information about phase transitions, structures and intermolecular interactions between the A-cation and the framework, even in complex hybrid organic-inorganic perovskites with highly disordered phases.


Asunto(s)
Azidas/química , Compuestos de Calcio/química , Rastreo Diferencial de Calorimetría/métodos , Óxidos/química , Espectrometría Raman/métodos , Titanio/química , Cadmio/química , Cationes/química , Transición de Fase , Temperatura , Vibración
13.
ACS Appl Mater Interfaces ; 12(42): 47820-47830, 2020 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-32990423

RESUMEN

The past few decades have seen the development of new bone cancer therapies, triggered by the discovery of new biomaterials. When the tumoral area is small and accessible, the common clinical treatment implies the tumor mass removal followed by bone reconstruction or consolidation with a bioceramic or a metallic scaffold. Even though the treatment also involves chemotherapy or radiotherapy, resurgence of cancer cells remains possible. We have thus designed a new kind of heterostructured nanobiomaterial, composed of SiO2-CaO bioactive glass as the shell and superparamagnetic γ-Fe2O3 iron oxide as the core in order to combine the benefits of bone repair thanks to the glass bioactivity and cancer cell destruction through magnetic hyperthermia. These multifunctional core-shell nanoparticles (NPs) have been obtained using a two-stage procedure, involving the coprecipitation of 11 nm sized iron oxide NPs followed by their encapsulation inside a bioactive glass shell by sol-gel chemistry. The as-produced spherical multicore-shell NPs show a narrow size distribution of 73 ± 7 nm. Magnetothermal loss measurements by calorimetry under an alternating magnetic field and in vitro bioactivity assessment performed in simulated body fluid showed that these heterostructures exhibit a good heating capacity and a fast mineralization process (hydroxyapatite forming ability). In addition, their in vitro cytocompatibility, evaluated in the presence of human mesenchymal stem cells during 3 and 7 days, has been demonstrated. These first findings suggest that γ-Fe2O3@SiO2-CaO heterostructures are a promising biomaterial to fill bone defects resulting from bone tumor resection, as they have the ability to both repair bone tissue and act as thermoseeds for cancer therapy.


Asunto(s)
Antineoplásicos/uso terapéutico , Materiales Biocompatibles/uso terapéutico , Neoplasias Óseas/tratamiento farmacológico , Células Madre Mesenquimatosas/efectos de los fármacos , Nanopartículas/química , Antineoplásicos/química , Materiales Biocompatibles/química , Compuestos de Calcio/química , Células Cultivadas , Óxido Ferrosoférrico/química , Humanos , Óxidos/química , Tamaño de la Partícula , Dióxido de Silicio/química , Propiedades de Superficie
14.
Molecules ; 25(18)2020 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-32906576

RESUMEN

Essential oils of sweet lime peel, a waste by-product in the juice industry, were extracted using the vacuum assisted solvent free microwave extraction (VASFME) method. The effects of microwave output power (500-1000 W) and extraction time (20-30 min) on the essential oils yield and antimicrobial property were investigated. Optimal conditions were observed at 797.844 W microwave output power and 30 min extraction time. The essential oils yield and antimicrobial property under these conditions were 0.792 ± 0.03% and 18.25 ± 1.45 mm, respectively, which agrees with the predicted values of 0.757% and 16.50 mm. The essential oils were extracted at optimized conditions and analyzed through GCMS for compound identification. A total of 49 compounds were identified, with limonene content (43.47%) being the highest among all sweet lime peel oil compounds. Moreover, the sweet lime peels were subjected to ultrasound pre-treatment before microwave extraction. The ultrasound pre-treatment helped to increase the essential oils yield from 0.84 to 1.06% as the treatment time increased from 30 to 90 min. The increase in yield was 37.66% more compared to VASFME at 90 min treatment time.


Asunto(s)
Compuestos de Calcio/química , Microondas , Aceites Volátiles/farmacología , Óxidos/química , Extractos Vegetales/química , Ondas Ultrasónicas , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Fraccionamiento Químico/métodos , Fenómenos Químicos , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/química , Aceites Volátiles/aislamiento & purificación , Solventes
15.
PLoS One ; 15(8): e0237612, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32790731

RESUMEN

Seventeen glass vessels and twenty glass beads recovered from the excavations at the ancient city of Malindi and the archaeological site of Mambrui in Kenya, east Africa were analysed using electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results show that all of the glass samples are soda-lime-silica glass. They belong to the high alumina -plant ash glass type, characterised by high alumina and relatively low calcium contents, widely distributed in eastern (10th- 16th centuries AD) and southern Africa (13th - 15th centuries AD), Central Asia (9th- 14th centuries AD) and southeast Asia (12th- 13th centuries AD), made with plant ashes and sands. This is an understudied glass type for which previous research has indicated there were three types. When compared with published research on such glasses using Zr, Ti, Ba, Cr, La, Li, Cs, Na2O, MgO and CaO we have identified at least four different compositional groups of v-Na-Al glass: Types A, B, C and D. By comparing the results with contemporary v-Na-Al glass vessels and beads from Central Asia, Africa, and southeast Asia we show that most of the Malindi and Mambrui glass share similar characteristics to the compositions of Mapungubwe Oblate and some of the Madagascar glass beads from southern Africa. They belong to Type A v-Na-Al glass which is characterised by an elevated level of Ti and Ba and a relatively high ratios of Cr/La, relatively low Zr concentrations and low ratios of Zr/Ti. Differences in Zr, Li, MgO and Na2O concentrations in Type A glass indicates that there are subgroups which might derive from different glass workshop(s) specialising in Type A v-Na-Al glass production. Comparison with the chemical compositions of glass from Ghazni, Afghanistan and Termez, Uzbekistan, and by using lead isotope analysis, we suggest v-Na-Al glass was manufactured in Central Asia and possibly worked into vessels and beads there.


Asunto(s)
Compuestos de Calcio/química , Vidrio/química , Óxidos/química , Plantas/química , Dióxido de Silicio/química , Hidróxido de Sodio/química , Oligoelementos/análisis , Oligoelementos/historia , África Oriental , Óxido de Aluminio , Arqueología , Historia del Siglo XV , Historia del Siglo XVI , Océano Índico , Marcaje Isotópico/métodos , Kenia , Espectrometría de Masas
16.
ACS Appl Mater Interfaces ; 12(27): 30449-30456, 2020 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-32558536

RESUMEN

Microbial electrosynthesis (MES) is an electricity-driven technology for the microbial reduction of CO2 to organic commodities. However, the limited solubility of CO2 in a solution and the inefficient electron transfer make it impossible for microorganisms to obtain an efficient surface for catalytic interaction, thus resulting in the low efficiency of MES. To address this, we introduce a multifunctional perovskite-based cathode material Pr0.5(Ba0.5Sr0.5)0.5Co0.8Fe0.2O3-δ-carbon felt (Pr0.5BSCF-CF), which provides a simultaneously significant increase in CO2 absorption and hydrogen production. As a result, the volumetric acetate production rate of MES obtained by Pr0.5BSCF-CF is 0.24 ± 0.01 g L-1 day-1, and it achieves a maximum acetate titer of 13.74 ± 0.20 g L-1 within 70 days. An adequate supply of CO2 and H2 also provides a sufficient amount of substrates and energy for the self-replication of the biocatalysts in the MES reactor. This effect not only increases the amount of biocatalysts but also optimizes the functions of the biocatalysts; the above benefits further improve the production efficiency of the MES system. This strategy demonstrates that the development of perovskite-based multifunctional cathodes with a simultaneous supplementation of substrates and electrons is a promising approach toward improving the MES efficiency.


Asunto(s)
Compuestos de Calcio/química , Óxidos/química , Titanio/química , Dióxido de Carbono/química , Catálisis , Técnicas Electroquímicas/métodos , Electrodos
17.
Anal Chem ; 92(10): 6822-6826, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32378879

RESUMEN

Exploring efficient luminophores in the electrochemiluminescence (ECL) system is highly desired to pursue a sensitive ECL sensing platform. Herein, the black phosphorus nanosheets (BP NSs) with excellent ECL properties are investigated and serve as the luminophore with the coreactant of peroxydisulfate (S2O82-) solution. Moreover, owing to the overlapping of emission and absorbance spectra, effective resonance energy transfer (RET) is realized between the BP NSs and the introduced Au nanoparticles. In order to achieve the portable and miniaturized developing trends for the paper-based ECL sensing platform, a paper-based perovskite solar cell (PSC) device is designed to act as the power source to replace the commonly utilized expensive and cumbersome electrochemical workstation. Benefiting from that, a PSC driven paper-based constant potential ECL-RET sensing platform is constructed, thereby realizing sensitive microRNAs (miRNAs) detection. What's more, to attain the preferable analytical performance, the duplex-specific nuclease (DSN) is also introduced to assist the target recycling signal amplification strategy. Based on this, highly sensitive detection of miRNA-107 with a range from 0.1 pM to 15 nM is achieved by this designed sensing platform. Most importantly, this work not only pioneers a precedent for developing a high-sensitivity PSC triggered ECL sensing platform but also explores the application prospect of BP nanomaterial in the field of bioanalysis.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Mediciones Luminiscentes , Papel , Fósforo/análisis , Energía Solar , Compuestos de Calcio/química , Óxidos/química , Titanio/química
18.
Nat Commun ; 11(1): 1735, 2020 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-32269223

RESUMEN

The therapeutic effect of reactive oxygen species (ROS)-involved cancer therapies is significantly limited by shortage of oxy-substrates, such as hypoxia in photodynamic therapy (PDT) and insufficient hydrogen peroxide (H2O2) in chemodynamic therapy (CDT). Here, we report a H2O2/O2 self-supplying nanoagent, (MSNs@CaO2-ICG)@LA, which consists of manganese silicate (MSN)-supported calcium peroxide (CaO2) and indocyanine green (ICG) with further surface modification of phase-change material lauric acid (LA). Under laser irradiation, ICG simultaneously generates singlet oxygen and emits heat to melt the LA. The exposed CaO2 reacts with water to produce O2 and H2O2 for hypoxia-relieved ICG-mediated PDT and H2O2-supplying MSN-based CDT, acting as an open source strategy for ROS production. Additionally, the MSNs-induced glutathione depletion protects ROS from scavenging, termed reduce expenditure. This open source and reduce expenditure strategy is effective in inhibiting tumor growth both in vitro and in vivo, and significantly improves ROS generation efficiency from multi-level for ROS-involved cancer therapies.


Asunto(s)
Quimioterapia , Fotoquimioterapia , Especies Reactivas de Oxígeno/metabolismo , Animales , Circulación Sanguínea , Compuestos de Calcio/química , Línea Celular Tumoral , Supervivencia Celular , Sinergismo Farmacológico , Femenino , Humanos , Peróxido de Hidrógeno/metabolismo , Verde de Indocianina/química , Ácidos Láuricos/sangre , Ácidos Láuricos/química , Imagen por Resonancia Magnética , Manganeso/química , Ratones Endogámicos BALB C , Nanopartículas/química , Nanopartículas/ultraestructura , Óxidos/química , Silicatos/química , Superóxidos/metabolismo , Distribución Tisular
19.
Ecotoxicol Environ Saf ; 196: 110539, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32247959

RESUMEN

Contamination of arable land with trace metals is a global environmental issue which has serious consequences on human health and food security. Present study evaluates the adsorption of cadmium (Cd) and lead (Pb) by using different quantities of composite of sepiolite, organic manure and lime (SOL) at field and laboratory scale (batch experiments). Characterization of SOL by SEM, EDS and FTIR spectroscopy revealed the presence of elemental and functional groups (hydroxyl, C⋯H and -COOH groups) on its surface. The field experiment was performed in a paddy field of gleysol having moderate contamination of Cd and Pb (0.64 mg kg-1 and 53.44 mg kg-1). Here, different rates of SOL (0.25, 0.5, 1, 1.5 and 2% w/w) were applied by growing low and high Cd accumulator rice cultivars. Application of SOL at 2% w/w showed considerable efficiency to increase soil pH (up to 19%) and to reduce available Cd (42-66%) and Pb (22-55%) as compared to the control. Moreover, its application reduced metal contents in roots, shoots and grains of rice by 31%, 36% and 72% (for Cd) and 41%, 81% and 84% (for Pb), respectively in low accumulator cultivar. Further, the batch sorption experiment was performed to evaluate the adsorption capacity of SOL in a wide range of contamination. Obtained sorption data was better fitted to the Langmuir equation. Our results highlight the strong efficiency of composite treatment for an enhanced in-situ metal immobilization under field and lab conditions. Further, applied treatments greatly reduced the metal contents in rice grains. In a nut shell, application of SOL in a contaminated gleysol should be considered for soil remediation and safe food production.


Asunto(s)
Cadmio/química , Compuestos de Calcio/química , Plomo/química , Silicatos de Magnesio/química , Estiércol , Óxidos/química , Adsorción , Disponibilidad Biológica , Cadmio/farmacocinética , Plomo/farmacocinética , Oryza/metabolismo , Raíces de Plantas/metabolismo , Contaminantes del Suelo/química , Contaminantes del Suelo/farmacocinética
20.
Ecotoxicol Environ Saf ; 194: 110384, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32126412

RESUMEN

Electrolytic manganese residue (EMR) contains a large amount of NH4+-N and Mn2+ and can negatively impact the environment. A stabilization treatment of soluble contaminants in the EMR is necessary for its reuse and safe stacking. This study presents experimental results for the stabilization of NH4+-N and Mn2+ in the EMR using phosphogypsum leachate as a low-cost phosphate source and MgO/CaO (PLMC) process. The results demonstrated that the stabilization efficiency of NH4+-N and Mn2+ was 93.65% and 99.99%, respectively, under the following conditions: a phosphogypsum leachate dose of 1.5 mL g-1, an added MgO dose of 0.036 g g-1, an added CaO dose of 0.1 g g-1 and a reaction time of 2 h. The stabilization effect of the PLMC process was higher and more cost effective than that of using Na3PO4·12H2O and MgO/CaO. The concentration of NH4+-N and Mn2+ in the leaching liquor decreased to 80 mg L-1 and 0.5 mg L-1, respectively, after the stabilization under the optimum conditions. The stabilization characteristics indicated that NH4+-N was stabilized to form NH4MgPO4·6H2O (struvite) and that Mn2+ was stabilized to form Mn5(PO4)2(OH)4, Mn3(PO4)2·3H2O and Mn(OH)2. PO43--P, F-, and heavy metal ions of the phosphogypsum leachate were removed from the leaching liquor and stabilized in the treated EMR.


Asunto(s)
Compuestos de Calcio/química , Sulfato de Calcio/química , Óxido de Magnesio/química , Manganeso/análisis , Óxidos/química , Fósforo/química , Amoníaco/análisis , Amoníaco/química , Electrólisis , Electrólitos , Contaminantes Ambientales/análisis , Contaminantes Ambientales/química , Residuos Industriales/análisis , Manganeso/química , Solubilidad , Estruvita/análisis , Estruvita/química
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