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1.
Chemosphere ; 361: 142569, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38852627

RESUMEN

Chemical oxo-precipitation (COP) is an enhanced precipitation method for boron removal with the conversion of boric acid to perborate anions. When using barium-based precipitant, the boron can be effectively precipitated as barium perborates (BaPBs). The phase transformation of BaPBs from amorphous (A-BaPB, Ba(B(OH)3OOH)2) to crystalline (C-BaPB, BaB2(OO)2(OH)4) form is crucial for effective boron removal. However, scaling up this phase transformation of BaPBs is hindered by poor diffusion. This study aims to promote the growth of C-BaPB through seed-induced crystal growth, eliminating the need for phase transformation. By examining the relationship between crystal growth rate and supersaturation, surface spiral growth was identified as the rate-limiting step of the growth of micron-sized seeds near pHpzc. To enable continuous crystal growth, granular seeds of C-BaPB were prepared and employed as the medium for fluidized-bed crystallization (FBC). The system reached steady state 3 hydraulic retention times, achieving 90% boron removal. The effect of surface loading, ionic strength, and dosages on steady-state crystal growth rate was studied, revealing a shift of the rate-limiting step in FBC to diffusion. Lastly, the system that constituted of two FBCs in-series for sequential crystallization of A-BaPB and C-BaPB was demonstrated. The integrated system provided 97.8% of boron removal from synthetic wastewater containing 500 mg-B/L, with 92.3% of boron crystallized on the granular seeds of BaPBs.


Asunto(s)
Bario , Boro , Cristalización , Boro/química , Bario/química , Boratos/química , Precipitación Química , Contaminantes Químicos del Agua/química
2.
Chemosphere ; 361: 142548, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38852637

RESUMEN

This study evaluated the effectiveness of using nanocomposite (NCs) of xanthan gum grafted polyacrylamide crosslinked Borax - iron oxide nanoparticle (XG-g-pAAm-CL-Borax-IONP) to remove the amoxicillin antibiotic (AMX) from an aquatic environment. To confirm the structural characteristics of the prepared XG-g-pAAm-CL-Borax-IONP NCs, unique characterization methods (XRD, FT-IR, FE-SEM, EDX, BET, TGA, Zeta, and VSM) were used. Adsorption experimental setups were performed with the influence of solution pH (4-9), the effect of adsorbent dose (0.003-0.02 g), the effect of contact time (5-45 min), and the effect of initial AMX concentration (50-400 mg/L) to achieve the most efficient adsorption conditions. Based on the Freundlich isotherm model, XG-g-pAAm-CL-Borax-IONP NCs provided the maximum AMX adsorption capacity of 1183.639 mg/g. This research on adsorption kinetics also established that the pseudo-second-order model (R2 = 0.991) is outstanding compatibility with the experimental results. AMX adsorption on the NCs may occur through intermolecular hydrogen bonding, diffusion, and trapping into the polymer network. Even after five cycles, these NCs still displayed the best performance. Based on these results, XG-g-pAAm-CL-Borax-IONP NCs may be a viable material for the purification of AMX from contaminated water.


Asunto(s)
Resinas Acrílicas , Amoxicilina , Boratos , Nanocompuestos , Polisacáridos Bacterianos , Contaminantes Químicos del Agua , Nanocompuestos/química , Contaminantes Químicos del Agua/química , Resinas Acrílicas/química , Amoxicilina/química , Polisacáridos Bacterianos/química , Adsorción , Boratos/química , Cinética , Antibacterianos/química , Purificación del Agua/métodos , Concentración de Iones de Hidrógeno
3.
J Nanobiotechnology ; 22(1): 229, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38720321

RESUMEN

Efficiently removing excess reactive oxygen species (ROS) generated by various factors on the ocular surface is a promising strategy for preventing the development of dry eye disease (DED). The currently available eye drops for DED treatment are palliative, short-lived and frequently administered due to the short precorneal residence time. Here, we developed nanozyme-based eye drops for DED by exploiting borate-mediated dynamic covalent complexation between n-FeZIF-8 nanozymes (n-Z(Fe)) and poly(vinyl alcohol) (PVA) to overcome these problems. The resultant formulation (PBnZ), which has dual-ROS scavenging abilities and prolonged corneal retention can effectively reduce oxidative stress, thereby providing an excellent preventive effect to alleviate DED. In vitro and in vivo experiments revealed that PBnZ could eliminate excess ROS through both its multienzyme-like activity and the ROS-scavenging activity of borate bonds. The positively charged nanozyme-based eye drops displayed a longer precorneal residence time due to physical adhesion and the dynamic borate bonds between phenyboronic acid and PVA or o-diol with mucin. The in vivo results showed that eye drops could effectively alleviate DED. These dual-function PBnZ nanozyme-based eye drops can provide insights into the development of novel treatment strategies for DED and other ROS-mediated inflammatory diseases and a rationale for the application of nanomaterials in clinical settings.


Asunto(s)
Síndromes de Ojo Seco , Soluciones Oftálmicas , Especies Reactivas de Oxígeno , Soluciones Oftálmicas/química , Soluciones Oftálmicas/farmacología , Síndromes de Ojo Seco/tratamiento farmacológico , Animales , Especies Reactivas de Oxígeno/metabolismo , Ratones , Estrés Oxidativo/efectos de los fármacos , Córnea/efectos de los fármacos , Córnea/metabolismo , Alcohol Polivinílico/química , Humanos , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Boratos/química , Nanopartículas/química , Masculino
4.
ACS Appl Bio Mater ; 7(6): 3828-3840, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38750624

RESUMEN

Borate glass transforms into hydroxycarbonate apatite more rapidly than silicate glass. This research aims to evaluate strontium's structural and biological effects on borate bioactive glass (BBG) and the influence of strontium concentrations (0%, 5%, 10%, and 15% Sr) prepared via the sol-gel method. The study reveals significant findings related to the physicochemical properties of the glass. Immersion of the glass powders in a simulated body fluid (SBF) led to the development of a hydroxyapatite (HAP) layer on the glass surfaces. This transformation was verified through X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) analyses. In particular, 5% strontium exhibited gradual degradation, resulting in particle sizes below 100 nm. The BBG-15%Sr demonstrates heightened pathogenic activity as it shows a significant inhibition zone of 14 mm at 250 µg/mL, surpassing other substituted BBGs. It effectively combats Gram-positive bacteria, completely inhibiting MRSA growth at 50 µg/mL. This underscores its robust biofilm disruption capabilities, eradicating biofilms, even at minimal concentrations after prolonged exposure. C. elegans when subjected to BBG-15%Sr shows less ROS production when compared with the others. Moreover, the results suggest that the modified glass could be a potential material for the treatment of osteomyelitis-affected bone repair.


Asunto(s)
Antibacterianos , Materiales Biocompatibles , Boratos , Vidrio , Ensayo de Materiales , Staphylococcus aureus Resistente a Meticilina , Osteomielitis , Estroncio , Estroncio/química , Estroncio/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Boratos/química , Boratos/farmacología , Vidrio/química , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/síntesis química , Osteomielitis/tratamiento farmacológico , Osteomielitis/microbiología , Tamaño de la Partícula , Pruebas de Sensibilidad Microbiana , Animales , Propiedades de Superficie
5.
Angew Chem Int Ed Engl ; 63(29): e202404286, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38712936

RESUMEN

Perhalogenated closo-borates represent a new class of membrane carriers. They owe this activity to their chaotropicity, which enables the transport of hydrophilic molecules across model membranes and into living cells. The transport efficiency of this new class of cluster carriers depends on a careful balance between their affinity to membranes and cargo, which varies with chaotropicity. However, the structure-activity parameters that define chaotropic transport remain to be elucidated. Here, we have studied the modulation of chaotropic transport by decoupling the halogen composition from the boron core size. The binding affinity between perhalogenated decaborate and dodecaborate clusters carriers was quantified with different hydrophilic model cargos, namely a neutral and a cationic peptide, phalloidin and (KLAKLAK)2. The transport efficiency, membrane-lytic properties, and cellular toxicity, as obtained from different vesicle and cell assays, increased with the size and polarizability of the clusters. These results validate the chaotropic effect as the driving force behind the membrane transport propensity of boron clusters. This work advances our understanding of the structural features of boron cluster carriers and establishes the first set of rational design principles for chaotropic membrane transporters.


Asunto(s)
Boro , Boro/química , Boro/metabolismo , Humanos , Transporte Biológico , Compuestos de Boro/química , Compuestos de Boro/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Boratos/química , Boratos/metabolismo
6.
Talanta ; 276: 126244, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38754185

RESUMEN

The detections of H2O2 and catalase play an important role in daily life. This study introduces a paper-based flow sensor that is specifically designed to detect H2O2 and catalase. The sensor utilizes a hydrogel composed of cross-linked 4-carboxyphenylboronic acid and polyvinyl alcohol. When H2O2 is in contact with the hydrogel, the B-C bonds of the hydrogel undergo a reactive process, causing decomposition of the hydrogel. The pH indicator strip enables the visual monitoring of the viscosity change that occurs during the gel-sol transition. The quantification of H2O2 is accomplished by assessing the proportion of water coverage on the pH indicator strip. The sensor shows a detection limit of 0.077 wt% and is applicable for the quantitative measurement of H2O2 in routinely used disinfectants. Furthermore, the presence of catalase is effectively identified and the detection of catalase in milk is successfully fulfilled. In summary, this work proposes a simple, user-friendly, label-free, and cost-effective method for constructing a paper-based flow sensor using borate cross-linked polyvinyl alcohol hydrogel, showing great potential for detecting H2O2 and catalase in various practical scenarios.


Asunto(s)
Boratos , Catalasa , Peróxido de Hidrógeno , Papel , Alcohol Polivinílico , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Alcohol Polivinílico/química , Catalasa/química , Boratos/química , Hidrogeles/química , Animales , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentación , Leche/química , Límite de Detección , Reactivos de Enlaces Cruzados/química , Concentración de Iones de Hidrógeno
7.
Int J Biol Macromol ; 269(Pt 2): 132133, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38719004

RESUMEN

In this study, sodium pentaborate pentahydrate (NaB) and Hypericum perforatum (HP) oil were incorporated into polyvinyl alcohol (PVA) and chitosan (CH) polymer blend to obtain membranes by solution casting method. In order to see the synergistic effects of NaB and HP oil on the biological and physical properties of the membranes NaB and HP oil were incorporated into membrane matrix in different ratios. Fourier-transform infrared spectroscopy (FTIR) results showed that no significant bond formation between the bioactive components and the PVA:CH matrix. According to mechanical test results, Young's Modulus and elongation at break decreased from 426 MPa to 346 MPa and 52.23 % to 15.11 % for neat PVA:CH membranes and NaB and HP oil incorporated PVA:CH (PVA:CH@35NaB:HP) membranes, respectively. Antimicrobial activity tests have shown the membranes were over 99 % effective against Escherichia coli, Staphylococcus aureus, and Candida albicans, underlining their potential for infection control. Cytocompatibility assay performed with Human Dermal Fibroblast (HDFa) cells highlight the biocompatibility of the membranes, revealing 74.84 % cell viability after 72 h. The properties of NaB and HP oil doped PVA:CH based membranes obtained from these experiments reveal the promise of a versatile membrane for applications in wound healing, tissue engineering and other biomedical fields.


Asunto(s)
Quitosano , Hypericum , Membranas Artificiales , Alcohol Polivinílico , Quitosano/química , Quitosano/farmacología , Hypericum/química , Alcohol Polivinílico/química , Humanos , Boratos/química , Boratos/farmacología , Aceites de Plantas/química , Aceites de Plantas/farmacología , Antiinfecciosos/farmacología , Antiinfecciosos/química , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Candida albicans/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Escherichia coli/efectos de los fármacos , Fibroblastos/efectos de los fármacos
8.
ACS Sens ; 9(5): 2634-2644, 2024 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-38669562

RESUMEN

Gestational diabetes mellitus (GDM) is one of the most common metabolic disorders during pregnancy, leading to serious complications for pregnant women and a threat to life safety of infants. Therefore, it is particularly important to establish a multipurpose monitoring pathway to important physiological indicators of pregnant women. In this work, three kinds of double network hydrogels are prepared with poly(vinyl alcohol) (PVA), borax, and cellulose ethers with varying substituents of methyl (methyl cellulose, MC), hydroxypropyl (hydroxypropyl cellulose, HPC), or both (hydroxypropyl methyl cellulose, HPMC), respectively. The corresponding toughness (143.9, 102.3, and 135.9 kJ cm-3) and conductivity (0.69, 0.45, and 0.51 S m-1) of the hydrogels demonstrate that PB-MC was endowed with the prominent performance. Molecular dynamics simulations further revealed the essence that hydrogen bond interactions between PVA and cellulose ethers play a critical role in regulating the structure and properties of hydrogels. Thermochromic capsule powders (TCPs) were subsequently doped in to achieve a composite hydrogel (TCPs@PB-MC) to indicate the change in human body temperature. Furthermore, the process of the TCPs@PB-MC response to glucose, pH, and temperature was tracked in-depth through the electrochemical window. This work provides a novel strategy for all-in-one health management of GDM.


Asunto(s)
Celulosa , Diabetes Gestacional , Hidrogeles , Alcohol Polivinílico , Femenino , Embarazo , Humanos , Hidrogeles/química , Celulosa/química , Celulosa/análogos & derivados , Alcohol Polivinílico/química , Boratos/química , Dispositivos Electrónicos Vestibles , Glucosa/química , Simulación de Dinámica Molecular , Temperatura , Concentración de Iones de Hidrógeno , Enlace de Hidrógeno
9.
Talanta ; 274: 126053, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38599121

RESUMEN

Borax is strictly regulated in the food processing and pharmaceutical industry due to its physiological toxicity, and the development of a direct analytical method is essential for effectively monitoring the borax abuse. In this work, the fluorescence properties of flavonoids, including flavones, isoflavones and flavonols, were systematically investigated from aqueous to borax solutions, and it was found that the weak intrinsic fluorescence of flavonols could be pervasively sensitized by borax. A natural flavonol, morin, was subsequently chosen as a representative probe to develop a turn-on fluorescence sensing method for borax analysis, which achieved a linear response spanning four orders of magnitude with a detection limit of 1.07 µM (0.22 µg mL-1 in terms of Na2B4O7 content). Furthermore, a smartphone-assisted paper-based test device was designed and constructed by 3D printing technology. Using morin-impregnated test strips as the carrier, the borax could be visually detected by the RGB signals of the captured images, with a detection limit of 0.13 mM (27.05 µg mL-1 for Na2B4O7). Combining ion exchange treatment for food samples and sodium periodate oxidation for drug samples, the developed methods were successfully applied for the direct analysis of borax in various products with the recoveries of 86.9-106.3% for traditional fluorescence analysis and 82.7-108.8% for smartphone-assisted fluorescence sensing. The fluorescence property of the morin-borax system was studied using time-dependent density functional theory, and the sensing mechanism was discussed in conjunction with experimental research.


Asunto(s)
Flavonas , Flavonoides , Flavonoles , Papel , Teléfono Inteligente , Espectrometría de Fluorescencia , Flavonoles/análisis , Espectrometría de Fluorescencia/métodos , Flavonoides/análisis , Boratos/química , Límite de Detección , Colorantes Fluorescentes/química , Fluorescencia
10.
Luminescence ; 39(4): e4732, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38556715

RESUMEN

In the present work, glass samples in the (100 - x)B2O3-xLi2O binary system, with x varying from 30 to 50 mol%, were prepared using the conventional melting and moulding method, with the main objective of evaluating the thermoluminescence response when exposing these materials to ultraviolet (UV) radiation. Complementary analysis based on density, optical absorption on the UV-visible region (UV-vis absorbance), Fourier transform infrared spectroscopy on the medium region, X-ray diffraction, and differential thermal analysis measurements were performed. Thermoluminescence measurements of vitreous samples showed glow curves with at least one peak with a maximum temperature of ~170°C after exposure to UV radiation in the temperature range 50-250°C. Samples were also exposed to beta radiation in the temperature range 25-275°C, also showing single peaks with a maximum temperature of ~150°C.


Asunto(s)
Partículas beta , Boratos , Boratos/química , Compuestos de Litio , Temperatura
11.
Chemistry ; 30(31): e202304375, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38563634

RESUMEN

The clinical translation of polysarcosine (pSar) as polyethylene glycol (PEG) replacement in the development of novel nanomedicines creates a broad demand of polymeric material in high-quality making high-purity sarcosine N-carboxyanhydride (Sar-NCA) as monomer for its production inevitable. Within this report, we present the use of triethyloxonium tetrafluoroborate in Sar-NCA synthesis with focus on amino acid and chloride impurities to avoid the sublimation of Sar-NCAs. With a view towards upscaling into kilogram or ton scale, a new methodology of monomer purification is introduced by utilizing the Meerwein's Salt triethyloxonium tetrafluoroborate to remove chloride impurities by covalent binding and converting chloride ions into volatile products within a single step. The novel straightforward technique enables access to monomers with significantly reduced chloride content (<100 ppm) compared to Sar-NCA derived by synthesis or sublimation. The derived monomers enable the controlled-living polymerization in DMF and provide access to pSar polymers with Poisson-like molecular weight distribution within a high range of chain lengths (Xn 25-200). In conclusion, the reported method can be easily applied to Sar-NCA synthesis or purification of commercially available pSar-NCAs and eases access to well-defined hetero-telechelic pSar polymers.


Asunto(s)
Cloruros , Polimerizacion , Sarcosina , Sarcosina/química , Sarcosina/análogos & derivados , Cloruros/química , Polietilenglicoles/química , Polímeros/química , Boratos/química , Anhídridos/química , Péptidos
12.
Luminescence ; 39(3): e4714, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38506395

RESUMEN

In this study, the melt quenching approach is used to synthesize a lead borate-strontium-based glass system doped with samarium ions. Modifications in the glass network structure arising from the addition of various concentrations of Sm3+ ions were investigated via Fourier transform infrared (FTIR) spectroscopy. FTIR analysis revealed B-O-B bridges, BO3 , and BO4 units are present. UV-vis-NIR spectroscopic measurement was performed to study the optical absorption spectra. Optical constants such as optical bandgap energies, refractive indices, and other related parameters were evaluated. The lifetime fluorescence decay was measured and ranged between 1.04 and 1.88 ns. The photoluminescence spectra in the range 500-750 nm revealed four transitions from the ground state 6 G5/2 to the excited states 6 H5/2 , 6 H7/2 , 6 H9/2 and 6 H11/2 and J-O theory was utilized to study these optical transitions for Sm3+ ions. Calculations of the oscillator strengths and J-O intensity parameters were performed and the obtained J-O parameters followed the sequence Ω4 > Ω6 > Ω2 . The ratio O/R indicated a high lattice asymmetry around the samarium ions. The values of lifetimes and branching ratios for the fabricated samples emphasized their suitability to be used in laser applications. The current glass samples are good candidates for orange and red emission devices.


Asunto(s)
Boratos , Tungsteno , Boratos/química , Samario/química , Iones , Vidrio/química
13.
Daru ; 32(1): 197-206, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38366078

RESUMEN

BACKGROUND: Recent research indicates a prevalence of typical lung infections, such as pneumonia, in lung cancer patients. Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii stand out as antibiotic-resistant pathogens. Given this, there is a growing interest in alternative therapeutic avenues. Boron and zinc derivatives exhibit antimicrobial, antiviral, and antifungal properties. OBJECTIVES: This research aimed to establish the effectiveness of ZnO and ZB NPs in combating bacterial infections in lung cancer cell lines. METHODS: Initially, this study determined the minimal inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) of zinc oxide nanoparticles (ZnO NPs) and zinc borate (ZB) on chosen benchmark strains. Subsequent steps involved gauging treatment success through a lung cancer-bacteria combined culture and immunohistochemical analysis. RESULTS: The inhibitory impact of ZnO NPs on bacteria was charted as follows: 0.97 µg/mL for K. pneumoniae 700603, 1.95 µg/mL for P. aeruginosa 27853, and 7.81 µg/mL for Acinetobacter baumannii 19,606. In comparison, the antibacterial influence of zinc borate was measured as 7.81 µg/mL for Klebsiella pneumoniae 700603 and 500 µg/mL for both P. aeruginosa 27853 and A.baumannii 19606. After 24 h, the cytotoxicity of ZnO NPs and ZB was analyzed using the MTT technique. The lowest cell viability was marked in the 500 µg/mL ZB NPs group, with a viability rate of 48.83% (P < 0.001). However, marked deviations appeared at ZB concentrations of 61.5 µg/mL (P < 0.05) and ZnO NPs at 125 µg/mL. CONCLUSION: A synergistic microbial inhibitory effect was observed when ZnO NP and ZB were combined against the bacteria under investigation.


Asunto(s)
Acinetobacter baumannii , Antibacterianos , Boratos , Klebsiella pneumoniae , Neoplasias Pulmonares , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa , Óxido de Zinc , Óxido de Zinc/farmacología , Óxido de Zinc/química , Óxido de Zinc/administración & dosificación , Klebsiella pneumoniae/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Boratos/farmacología , Boratos/química , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Acinetobacter baumannii/efectos de los fármacos , Nanopartículas/química , Nanopartículas del Metal/química , Nanopartículas del Metal/administración & dosificación , Línea Celular Tumoral , Farmacorresistencia Bacteriana/efectos de los fármacos , Células A549 , Compuestos de Zinc/farmacología
14.
Int J Mol Sci ; 24(18)2023 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-37762043

RESUMEN

New organic nanostructures were synthesized by introducing 2-methylbenzimidazole (MBI) molecules from a melt, gas phase, or alcoholic solution into nanosized voids of borate porous glasses (PG), nanotubes of chrysotile asbestos (ChA), and mesoporous silica (MS). The incorporation of MBI into borate glasses with different pore sizes is accompanied by the appearance of several phases formed by nanocrystallites which have a MBI crystal structure, but somewhat differ in lattice parameters. The size of some crystallites significantly exceeds the size of nanopores, which indicates the presence of long-scale correlations of the crystal structure. The size of MBI nanocrystallites in ChA was close to the diameter of nanotubes (D ~10 nm), which shows the absence of crystal structure correlations. The XRD pattern of mesoporous silica filled by MBI does not exhibit reflections caused by MBI and a presence of MBI was confirmed only by the analysis of correlation function. The incorporation of MBI molecules into matrices is observed through optical IR absorption spectroscopy (FTIR) and photoluminescence. Introducing MBI in ChA and MS is followed by the appearance of bright green photoluminescence, the spectral structure of which is analogous to MBI crystals but slightly shifted in the blue region, probably due to a quantum-size effect. The influence of MBI inclusion in PG and ChA on the permittivity, dielectric losses, conductivity, and parameters of their hopping conductivity is analyzed.


Asunto(s)
Nanoporos , Nanotubos , Dióxido de Silicio/química , Boratos/química , Asbestos Serpentinas , Nanotubos/química
15.
J Mater Sci Mater Med ; 34(8): 42, 2023 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-37530851

RESUMEN

Impaired angiogenesis is one of the predominant reasons for non-healing diabetic wounds. Cobalt is well known for its capacity to induce angiogenesis by stabilizing hypoxia-inducible factor-1α (HIF-1α) and subsequently inducing the production of vascular endothelial growth factor (VEGF). In this study, Co-containing borate bioactive glasses and their derived fibers were fabricated by partially replacing CaO in 1393B3 borate glass with CoO. Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) analyses were performed to characterize the effect of Co incorporation on the glass structure, and the results showed that the substitution promoted the transformation of [BO3] into [BO4] units, which endow the glass with higher chemical durability and lower reaction rate with the simulated body fluid (SBF), thereby achieving sustained and controlled Co2+ ion release. In vitro biological assays were performed to assess the angiogenic potential of the Co-containing borate glass fibers. It was found that the released Co2+ ion significantly enhanced the proliferation, migration and tube formation of the Human Umbilical Vein Endothelial Cells (HUVECs) by upregulating the expression of angiogenesis-related proteins such as HIF-1α and VEGF. Finally. In vivo results demonstrated that the Co-containing fibers accelerated full-thickness skin wound healing in streptozotocin (STZ)-induced diabetic rat model by promoting angiogenesis and re-epithelialization.


Asunto(s)
Diabetes Mellitus , Cicatrización de Heridas , Ratas , Humanos , Animales , Factor A de Crecimiento Endotelial Vascular/metabolismo , Boratos/química , Cobalto , Neovascularización Fisiológica , Vidrio/química , Células Endoteliales de la Vena Umbilical Humana
16.
J Chem Phys ; 158(22)2023 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-37290074

RESUMEN

High-energy x-ray diffraction from molten and glassy BaB2O4 and BaB4O7 has been performed using aerodynamic levitation and laser heating over a wide range of temperatures. Remarkably, even in the presence of a heavy metal modifier dominating x-ray scattering, it was possible to extract accurate values for the tetrahedral, sp3, boron fraction, N4, which declines with increasing temperature, using bond valence-based mapping from the measured mean B-O bond lengths while accounting for vibrational thermal expansion. These are used within a boron-coordination-change model to extract enthalpies, ΔH, and entropies, ΔS, of isomerization between sp2 and sp3 boron. The results for BaB4O7, ΔH = 22(3) kJ mol-1 boron, ΔS = 19(2) J mol-1 boron K-1, agree quantitatively with those found previously for Na2B4O7. Analytical expressions for N4(J, T) and associated configurational heat capacity, CPconf(J, T), and entropy, Sconf(J, T), contributions are extended to cover a wide composition range 0 ≤ J = BaO/B2O3 ≤ 3 using a model for ΔH(J) and ΔS(J) derived empirically for lithium borates. Maxima in the CPconf(J, Tg) and fragility index contributions are thereby predicted for J ≲ 1, higher than the maximum observed and predicted in N4(J, Tg) at J ≃ 0.6. We discuss the utility of the boron-coordination-change isomerization model in the context of borate liquids containing other modifiers and the prospect of neutron diffraction to aid in empirical determinations of modifier-dependent effects, illustrated by new neutron diffraction data on Ba11B4O7 glass, its well-known α-polymorph, and lesser-known δ-phase.


Asunto(s)
Boratos , Boro , Entropía , Boratos/química , Bario , Calor
17.
Astrobiology ; 23(5): 605-615, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36862128

RESUMEN

Boron, as borate (or boric acid), is known as a mediator of the synthesis of ribose, ribonucleosides, and ribonucleotides (precursors of RNA) under plausible prebiotic conditions. With regard to these phenomena, the potential participation of this chemical element (as a constituent of minerals or hydrogels) for the emergence of prebiological homochirality is considered. This hypothesis is based on characteristics of crystalline surfaces as well as solubility of some minerals of boron in water or specific features of hydrogels with ester bonds from reaction of ribonucleosides and borate.


Asunto(s)
Boro , Ribonucleósidos , Humanos , Boro/química , Boratos/química , Minerales/química , Ribonucleósidos/química , Hidrogeles
18.
Molecules ; 28(4)2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36838745

RESUMEN

A comprehensive study focused on the preparation of disubstituted carboxonium derivatives of closo-decaborate anion [2,6-B10H8O2CC6H5]- was carried out. The proposed synthesis of the target product was based on the interaction between the anion [B10H11]- and benzoic acid C6H5COOH. It was shown that the formation of this product proceeds stepwise through the formation of a mono-substituted product [B10H9OC(OH)C6H5]-. In addition, an alternative one-step approach for obtaining the target derivative is postulated. The structure of tetrabutylammonium salts of carboxonium derivative ((C4H9)4N)[2,6-B10H8O2CC6H5] was established with the help of X-ray structure analysis. The reaction pathway for the formation of [2,6-B10H8O2CC6H5]- was investigated with the help of density functional theory (DFT) calculations. This process has an electrophile induced nucleophilic substitution (EINS) mechanism, and intermediate anionic species play a key role. Such intermediates have a structure in which one boron atom coordinates two hydrogen atoms. The regioselectivity for the process of formation for the 2,6-isomer was also proved by theoretical calculations. Generally, in the experimental part, the simple and available approach for producing disubstituted carboxonium derivative was introduced, and the mechanism of this process was investigated with the help of theoretical calculations. The proposed approach can be applicable for the preparation of a wide range of disubstituted derivatives of closo-borate anions.


Asunto(s)
Boratos , Boro , Boratos/química , Aniones/química , Boro/química , Isomerismo
19.
J Mater Chem B ; 11(5): 955-973, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36633185

RESUMEN

Because of their excellent biologically active qualities, bioactive glasses (BGs) have been extensively used in the biomedical domain, leading to better tissue-implant interactions and promoting bone regeneration and wound healing. Aside from having attractive characteristics, BGs are appealing as a porous scaffold material. On the other hand, such porous scaffolds should enable tissue proliferation and integration with the natural bone and neighboring soft tissues and degrade at a rate that allows for new bone development while preventing bacterial colonization. Therefore, researchers have recently become interested in a different BG composition based on borate (B2O3) rather than silicate (SiO2). Furthermore, apatite synthesis in the borate-based bioactive glass (BBG) is faster than in the silicate-based bioactive glass, which slowly transforms to hydroxyapatite. This low chemical durability of BBG indicates a fast degradation process, which has become a concern for their utilization in biological and biomedical applications. To address these shortcomings, glass network modifiers, active ions, and other materials can be combined with BBG to improve the bioactivity, mechanical, and regenerative properties, including its degradation potential. To this end, this review article will highlight the details of BBGs, including their structure, properties, and medical applications, such as bone regeneration, wound care, and dental/bone implant coatings. Furthermore, the mechanism of BBG surface reaction kinetics and the role of doping ions in controlling the low chemical durability of BBG and its effects on osteogenesis and angiogenesis will be outlined.


Asunto(s)
Boratos , Dióxido de Silicio , Boratos/química , Vidrio/química , Silicatos/química , Andamios del Tejido/química
20.
Int J Biol Macromol ; 231: 123284, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36657538

RESUMEN

Borate crosslinked guar gum gels have played a vital role in stimulating oil and gas wells for many years; however, the high dosage of guar gum in the existing fracturing fluid will increase the cost and cause more damage to the reservoir and ultimately affect the effect of stimulation. In this study, borate esters are modified onto polyethyleneimine (PEI) of different molecular weights, affording organic borate crosslinkers of different sizes. By analyzing the effect of crosslinker size on gel rheology, sand-carrying properties, and microstructure, it is observed that the crosslinking efficiency is most significantly enhanced when the crosslinker size is similar to the diameter of the guar gum molecules. This makes it possible for the gel to maintain good performance at low polymer concentrations and meet the performance requirements of fracturing, which provides new ideas for developing the next generation of economical, clean, and green fracturing fluids.


Asunto(s)
Boratos , Galactanos , Boratos/química , Galactanos/química , Mananos/química , Gomas de Plantas/química , Geles , Reología
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