Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 240
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Chem Mater ; 36(19): 9784-9792, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39398373

RESUMEN

Reorientational dynamics in solid electrolytes can significantly enhance the ionic conductivity, and understanding these dynamics can facilitate the rational design of improved solid electrolytes. Additionally, recent investigations on metal hydridoborate-based solid electrolytes have shown that the addition of a neutral ligand can also have a positive effect on the ionic conductivity. In this study, we investigate the dynamics in monomethylamine magnesium borohydride (Mg(BH4)2·CH3NH2) with quasielastic and inelastic neutron scattering, density functional theory calculations, and molecular dynamics simulations. The results suggest that the addition of methylamine significantly speeds up the reorientational frequency of the BH4 - anion compared to Mg(BH4)2. This is likely part of the explanation for the high Mg-ion transport observed for Mg(BH4)2·CH3NH2. Furthermore, while the dynamics of both the BH4 - anion and the CH3 group of the methylamine ligand is rapid, the NH2 group of the methylamine ligand exhibits much slower reorientations, as confirmed by both experimental and computational investigations. Notably, molecular dynamics calculations reveal mean square displacements of 0.387 Å2 for NH2, 1.503 Å2 for CH3, and 1.856 Å2 for BH4 - using a trajectory of 10 ps. This study confirms the simultaneous presence of fast dynamics and high ionic conductivity in a metal borohydride-based system and can function as an experimental foundation for future studies on dynamics in hydrogen-rich solid electrolytes.

2.
J Agric Food Chem ; 72(42): 23246-23257, 2024 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-39391963

RESUMEN

The aim of this study was to determine the osteogenic activity and mechanism of soybean peptide VVELLKAFEEKF (SOP) and the potential relationship between SOP and transforming growth factor-ß1 (TGF-ß1). The results show that SOP promotes MC3T3-E1 cell proliferation by altering cell progression. SOP induced cell differentiation and mineralization in a dose-dependent manner at 0.7-7 µM. Moreover, SOP stimulates osteoblast differentiation, which may be achieved through the activation of p38-MAPK and Smad2/3 signaling pathways. Furthermore, treatment with a TßRI inhibitor (SB525334) inhibited the phosphorylation levels of p38 and Smad2/3, which indicates the involvement of TßRI in the process of osteoblast differentiation caused by SOP. Besides, in non-FBS-cultured MC3T3-E1 cells, SOP and TGF-ß1 promoted the phosphorylation of Smad2/3 and alkaline phosphatase (ALP) activity, but the effect was lost when SOP was incubated separately, indicating that SOP stimulated osteoblast differentiation by promoting TGF-ß1 activity. In vivo, SOP significantly restores bone mineral density loss and behavioral deficits in a model of glucocorticoid-induced osteoporosis (GIOP) in zebrafish. These results suggest that SOP may have the function of promoting bone remodeling and may be used as a potential active factor for functional food development to prevent osteoporosis.


Asunto(s)
Diferenciación Celular , Glycine max , Osteoblastos , Osteogénesis , Proteínas de Soja , Factor de Crecimiento Transformador beta1 , Osteoblastos/efectos de los fármacos , Osteoblastos/citología , Osteoblastos/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Ratones , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Crecimiento Transformador beta1/genética , Proteínas de Soja/química , Proteínas de Soja/farmacología , Glycine max/química , Osteogénesis/efectos de los fármacos , Pez Cebra , Humanos , Transducción de Señal/efectos de los fármacos , Péptidos/farmacología , Péptidos/química , Proteína Smad2/metabolismo , Proteína Smad2/genética , Fosforilación/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Proteína smad3/metabolismo , Proteína smad3/genética , Proteínas Smad/metabolismo , Proteínas Smad/genética , Osteoporosis/tratamiento farmacológico , Osteoporosis/metabolismo
3.
Phys Chem Chem Phys ; 26(40): 25969-25976, 2024 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-39365254

RESUMEN

While a range of in situ characterisation techniques are available to probe CO2 adsorption processes, inelastic neutron scattering is scarcely used, primarily due to the reliance on hydrogeneous modes. Materials capable of adsorbing CO2, such as solid supported-amines contain a range of C-H and N-H species, which can be probed to explore the adsorption of CO2. Here we show the benefits of using inelastic neutron spectroscopy to probe CO2 adsorption with solid supported-amines, and the complementarity that can be achieved using different world-leading spectrometers.

4.
Nat Commun ; 15(1): 8697, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39379386

RESUMEN

Safe storage and utilisation of hydrogen is an ongoing area of research, showing potential to enable hydrogen becoming an effective fuel, substituting current carbon-based sources. Hydrogen storage is associated with a high energy cost due to its low density and boiling point, which drives a high price. Clathrates (gas hydrates) are water-based (ice-like) structures incorporating small non-polar compounds such as H2 in cages formed by hydrogen bonded water molecules. Since only water is required to construct the cages, clathrates have been identified as a potential solution for safe storage of hydrogen. In bulk, pure hydrogen clathrate (H2O-H2) only forms in harsh conditions, but confined in nanospaces the properties of water are altered and hydrogen storage at mild pressure and temperature could become possible. Here, specifically a hydrophobic mesoporous silica is proposed as a host material, providing a suitable nano-confinement for ice-like clathrate hydrate. The hybrid silica material shows an important decrease of the pressure required for clathrate formation (approx. 20%) compared to the pure H2O-H2 system. In-situ inelastic neutron scattering (INS) and neutron diffraction (ND) provided unique insights into the interaction of hydrogen with the complex surface of the hybrid material and demonstrated the stability of nano-confined hydrogen clathrate hydrate.

5.
J Am Chem Soc ; 2024 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-39365881

RESUMEN

The functionalization of metal-organic frameworks (MOFs) to enhance the adsorption of benzene at trace levels remains a significant challenge. Here, we report the exceptional adsorption of trace benzene in a series of zirconium-based MOFs functionalized with chloro groups. Notably, MFM-68-Cl2, constructed from an anthracene linker incorporating chloro groups, exhibits a remarkable benzene uptake of 4.62 mmol g-1 at 298 K and 0.12 mbar, superior to benchmark materials. In situ synchrotron X-ray diffraction, Fourier transform infrared microspectroscopy, and inelastic neutron scattering, coupled with density functional theory modeling, reveal the mechanism of binding of benzene in these materials. Overall, the excellent adsorption performance is promoted by an unprecedented cooperation between chloro-groups, the optimized pore size, aromatic functionality, and the flexibility of the linkers in response to benzene uptake in MFM-68-Cl2. This study represents the first example of enhanced adsorption of trace benzene promoted by -CH···Cl and Cl···π interactions in porous materials.

6.
Food Res Int ; 195: 114995, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39277255

RESUMEN

Common vetch protein, similar to pea protein, offers valuable qualities like being non-GMO, hypoallergenic, and nutritious. However, its strong beany flavor hinders consumer acceptance. This study explores enzymatic deamidation using glutaminase to address this issue. GC-MS analysis identified 54 volatile compounds in the raw material protein, with 2-pentylfuran, hexanal, and several nonenals contributing the most to the undesirable aroma. Principal component analysis (PCA) confirmed the effectiveness of glutaminase deamidation in removing these off-flavors. The study further reveals that deamidation alters the protein's secondary structure, with an increase in α - helix structure and a decrease in ß - sheet structure. The surface hydrophobicity increased from 587.33 ± 2.63 to 1855.63 ± 3.91 exposing hydrophobic clusters that bind flavor compounds. This disruption weakens the interactions that trap these undesirable flavors, ultimately leading to their release and a more pleasant aroma. These findings provide valuable insights for enzymatic deodorization of not only common vetch protein but also pea protein.


Asunto(s)
Glutaminasa , Glutaminasa/metabolismo , Glutaminasa/química , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/metabolismo , Gusto , Cromatografía de Gases y Espectrometría de Masas , Aromatizantes/química , Odorantes/análisis , Interacciones Hidrofóbicas e Hidrofílicas , Humanos , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Análisis de Componente Principal , Estructura Secundaria de Proteína
7.
Anal Methods ; 16(40): 6872-6876, 2024 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-39268762

RESUMEN

In this assay, based on the terminal protection of small-molecule-linked DNA, a new ultrasensitive real-time fluorescence strategy combined with an isothermal exponential amplification reaction (IEXPAR) has been established for protein assay. By the clever design of DNA, terminal protection is combined with efficient IEXPAR. The target protein explicitly binds to small molecules attached to the template DNA, protecting the template DNA from exonuclease I (Exo I) degradation. The added DNA primer hybridizes with the protected template DNA and triggers the following IEXPAR. IEXPAR has a super amplification efficiency of 106-109 times. The IEXPAR yields numerous double-stranded DNA (dsDNA) molecules. The fluorescence dye SYBR Green I (SG), which is sensitive to dsDNA, is used to determine the real-time fluorescence of the IEXPAR. Conversely, without the target protein, the template DNA is hydrolyzed by Exo I, failing to trigger the IEXPAR. The intriguing combination of IEXPAR and terminal protection realizes the ultrasensitive detection of protein. As low as 100 fmol L-1 SA and 200 pg mL-1 folic acid (FR) are accurately detected.


Asunto(s)
Técnicas de Amplificación de Ácido Nucleico , Técnicas de Amplificación de Ácido Nucleico/métodos , ADN/química , Colorantes Fluorescentes/química , Límite de Detección , Espectrometría de Fluorescencia/métodos , Humanos , Benzotiazoles/química , Quinolinas/química , Diaminas , Fluorescencia , Compuestos Orgánicos/química , Exodesoxirribonucleasas/química , Exodesoxirribonucleasas/metabolismo , Proteínas/química , Proteínas/análisis , Técnicas Biosensibles/métodos
8.
J Am Chem Soc ; 146(32): 22759-22776, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39092909

RESUMEN

Porous solids can accommodate and release molecular hydrogen readily, making them attractive for minimizing the energy requirements for hydrogen storage relative to physical storage systems. However, H2 adsorption enthalpies in such materials are generally weak (-3 to -7 kJ/mol), lowering capacities at ambient temperature. Metal-organic frameworks with well-defined structures and synthetic modularity could allow for tuning adsorbent-H2 interactions for ambient-temperature storage. Recently, Cu2.2Zn2.8Cl1.8(btdd)3 (H2btdd = bis(1H-1,2,3-triazolo-[4,5-b],[4',5'-i])dibenzo[1,4]dioxin; CuI-MFU-4l) was reported to show a large H2 adsorption enthalpy of -32 kJ/mol owing to π-backbonding from CuI to H2, exceeding the optimal binding strength for ambient-temperature storage (-15 to -25 kJ/mol). Toward realizing optimal H2 binding, we sought to modulate the π-backbonding interactions by tuning the pyramidal geometry of the trigonal CuI sites. A series of isostructural frameworks, Cu2.7M2.3X1.3(btdd)3 (M = Mn, Cd; X = Cl, I; CuIM-MFU-4l), was synthesized through postsynthetic modification of the corresponding materials M5X4(btdd)3 (M = Mn, Cd; X = CH3CO2, I). This strategy adjusts the H2 adsorption enthalpy at the CuI sites according to the ionic radius of the central metal ion of the pentanuclear cluster node, leading to -33 kJ/mol for M = ZnII (0.74 Å), -27 kJ/mol for M = MnII (0.83 Å), and -23 kJ/mol for M = CdII (0.95 Å). Thus, CuICd-MFU-4l provides a second, more stable example of optimal H2 binding energy for ambient-temperature storage among reported metal-organic frameworks. Structural, computational, and spectroscopic studies indicate that a larger central metal planarizes trigonal CuI sites, weakening the π-backbonding to H2.

9.
Int J Biol Macromol ; 276(Pt 1): 133640, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38969047

RESUMEN

The potential of using emulsion gels stabilized by binary plant protein nanoparticle mixtures for the encapsulation and delivery of lipophilic nutraceuticals was evaluated. The particle characteristics, physical stability, water diffusivity, microrheology, large amplitude oscillating shear (LAOS) properties, and in vitro digestion of emulsion gels prepared by different ratios of hydrolyzed rice glutelin fibrils (HRGFs) and pea protein nanoparticle (PNP) were characterized. The emulsion gel with P/H = 2:1 (0.84 µm) exhibited the best storage stability and freeze-thaw stability, as seen by the smaller oil droplet size (1.02 and 1.42 µm, respectively). Low-field pulsed NMR indicated that the majority of water in samples was highly mobile. All the samples were predominantly elastic-like materials. The P/H 2:1 emulsion gel had the lowest FI value (6.21 × 10-4 Hz), the highest MVI value (5.57 s/nm2), G'/ G″ values and enclosed area, showing that it had denser 3D network structures, higher stiffness values, and a high sensitivity to changes in strain. Additionally, P/H 2:1 emulsion gel had a relatively high lipid digestibility (96.1 %), curcumin bioaccessibility (58.9 %), and curcumin stability (94.2 %). This study showed that emulsion gels stabilized by binary protein nanoparticle mixtures (PNP/HRGF) have potential as edible delivery systems for lipophilic nutraceuticals.


Asunto(s)
Curcumina , Emulsiones , Geles , Glútenes , Nanopartículas , Oryza , Proteínas de Guisantes , Curcumina/química , Curcumina/farmacología , Emulsiones/química , Nanopartículas/química , Proteínas de Guisantes/química , Oryza/química , Glútenes/química , Geles/química , Hidrólisis , Tamaño de la Partícula , Reología , Composición de Medicamentos
10.
Sci Adv ; 10(30): eadm9963, 2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-39047094

RESUMEN

Polyvinyl chloride (PVC) is ubiquitous in everyday life; however, it is not recycled because it degrades uncontrollably into toxic products above 250°C. Therefore, it is of interest to controllably dechlorinate PVC at mild temperatures to generate narrowly distributed carbon materials. We present a catalytic route to dechlorinate PVC (~90% reduction of Cl content) at mild temperature (200°C) to produce gas H2 (with negligible coproduction of corrosive gas HCl) and carbon materials using Ga as a liquid metal (LM) catalyst. A LM was used to promote intimate contact between PVC and the catalytic sites. During dechlorination of PVC, Cl is sequestrated in the carbonaceous solid product. Later, chlorine is easily removed with an acetone wash at room temperature. The Ga LM catalyst is reusable, outperforms a traditional supported metal catalyst, and successfully converts (untreated) discarded PVC pipe.

11.
Nat Comput Sci ; 4(7): 522-531, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38997585

RESUMEN

Understanding the structure-property relationship is crucial for designing materials with desired properties. The past few years have witnessed remarkable progress in machine-learning methods for this connection. However, substantial challenges remain, including the generalizability of models and prediction of properties with materials-dependent output dimensions. Here we present the virtual node graph neural network to address the challenges. By developing three virtual node approaches, we achieve Γ-phonon spectra and full phonon dispersion prediction from atomic coordinates. We show that, compared with the machine-learning interatomic potentials, our approach achieves orders-of-magnitude-higher efficiency with comparable to better accuracy. This allows us to generate databases for Γ-phonon containing over 146,000 materials and phonon band structures of zeolites. Our work provides an avenue for rapid and high-quality prediction of phonon band structures enabling materials design with desired phonon properties. The virtual node method also provides a generic method for machine-learning design with a high level of flexibility.

12.
Food Chem ; 460(Pt 1): 140402, 2024 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-39059330

RESUMEN

Pea protein isolate (PPI)-hyaluronic acid (HA)-tannic acid (TA) ternary complexes were assembled using non-covalent interactions, their potential application in 3D printing and delivery of curcumin were investigated. As the HA-to-TA ratio in the complexes changed from 1:0 to 0:1, the oil-water interfacial tension first decreased and then increased, and the secondary structure of the proteins changed. The composition of the complexes (HA-to-TA ratio) was optimized to produce high internal phase emulsions (HIPEs) containing small uniform oil droplets with good storage and thermal stability. When the HA to TA ratio is 7:1 (P-H7-T1), HIPEs exhibited better viscosity, viscoelasticity, and thixotropy, which contributed to its preferable 3D printing. Moreover, curcumin-loaded HIPEs stabilized by P-H7-T1 showed a high lipid digestibility (≈101%) and curcumin bioaccessibility (≈79%). In summary, the PPI-HA-TA-stabilized HIPEs have good potential to be 3D-printable materials that could be loaded with bioactive components.


Asunto(s)
Curcumina , Emulsiones , Ácido Hialurónico , Proteínas de Guisantes , Impresión Tridimensional , Curcumina/química , Emulsiones/química , Proteínas de Guisantes/química , Ácido Hialurónico/química , Viscosidad , Tamaño de la Partícula , Polifenoles
13.
J Phys Chem A ; 128(28): 5676-5683, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-38968334

RESUMEN

The surface of Titan, Saturn's icy moon, is believed to be composed of various molecular minerals with a great diversity in structure and composition. Under the surface conditions, 93 K and 1.45 atm, most small molecules solidify and form minerals, including acetylene and ammonia. These two compounds can not only form single-component solids but also a 1:1 binary cocrystal that exhibits intriguing rotor phase behavior. This cocrystal is a putative mineral on Titan and other planetary bodies such as comets. In addition, the structure of the cocrystal is relevant to fundamental science as it can help better understand the emergence of rotor phases. Here, we present a detailed vibrational neutron spectroscopic study supported by a neutron powder diffraction study on the cocrystal and the single-phase solids. The experimentally observed spectral bands were assigned based on theoretical calculations. The established spectra-properties correlations for the cocrystal corroborate the observed properties. To the best of our knowledge, this study presents the first example of the application of neutron vibrational spectroscopy in studying Titan-relevant organic minerals.

14.
Anal Chim Acta ; 1314: 342781, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-38876519

RESUMEN

BACKGROUND: Okadaic acid (OA), as a diarrhetic shellfish poisoning, can increase the risk of acute carcinogenic or teratogenic effects for the ingestion of OA contaminated shellfish. At present, much effort has been made to graft immunoassay onto a paper substrate to make paper-based sensors for rapid and simple detection of shellfish toxin. However, the complicated washing steps and low protein fixation efficiency on the paper substrate need to be further addressed. RESULTS: A novel paper-tip immunosensor for detecting OA was developed combined with smartphone and naked eye readout. The trapezoid paper tip was consisted of quantitative and qualitative detection zones. To improve the OA antigen immobilization efficiency on the paper substrate, graphene oxide (GO)-assisted protein immobilization method was introduced. Meanwhile, Au nanoparticles composite probe combined with the lateral flow washing was developed to simplify the washing step. The OA antigen-immobilized zone, as the detection zone Ⅰ, was used for quantitative assay by smartphone imaging. The paper-tip front, as the detection zone Ⅱ, which could qualitatively differentiate OA pollution level within 45 min using the naked eye. The competitive immunoassay on the paper tip exhibited a wide linear range for detecting OA (0.02-50 ng∙mL-1) with low detection limit of 0.02 ng∙mL-1. The recovery of OA in spiked shellfish samples was in the range of 90.3 %-113.%. SIGNIFICANCE: These results demonstrated that the proposed paper-tip immunosensor could provide a simple, low-cost and high-sensitivity test for OA detection without the need for additional large-scale equipment or expertise. We anticipate that this paper-tip immunosensor will be a flexible and versatile tool for on-site detecting the pollution of marine products.


Asunto(s)
Técnicas Biosensibles , Oro , Grafito , Ácido Ocadaico , Papel , Teléfono Inteligente , Grafito/química , Ácido Ocadaico/análisis , Inmunoensayo/métodos , Oro/química , Nanopartículas del Metal/química , Proteínas Inmovilizadas/química , Límite de Detección , Animales , Anticuerpos Inmovilizados/inmunología , Anticuerpos Inmovilizados/química
15.
Chem Sci ; 15(21): 8197-8203, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38817566

RESUMEN

The functionalisation of organic linkers in metal-organic frameworks (MOFs) to improve gas uptake is well-documented. Although the positive role of free carboxylic acid sites in MOFs for binding gas molecules has been proposed in computational studies, relatively little experimental evidence has been reported in support of this. Primarily this is because of the inherent synthetic difficulty to prepare MOF materials bearing free, accessible -COOH moieties which would normally bind to metal ions within the framework structure. Here, we describe the direct binding of CO2 and C2H2 molecules to the free -COOH sites within the pores of MFM-303(Al). MFM-303(Al) exhibits highly selective adsorption of CO2 and C2H2 with a high selectivity for C2H2 over C2H4. In situ synchrotron X-ray diffraction and inelastic neutron scattering, coupled with modelling, highlight the cooperative interactions of adsorbed CO2 and C2H2 molecules with free -COOH and -OH sites within MFM-303(Al), thus rationalising the observed high selectivity for gas separation.

16.
Chem Commun (Camb) ; 60(46): 5912-5915, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38712387

RESUMEN

We report the high adsorption of NH3 in a titanium-based metal-organic framework, MFM-300(Ti), comprising extended [TiO6]∞ chains linked by biphenyl-3,3',5,5'-tetracarboxylate ligands. At 273 K and 1 bar, MFM-300(Ti) shows an exceptional NH3 uptake of 23.4 mmol g-1 with a record-high packing density of 0.84 g cm-3. Dynamic breakthrough experiments confirm the excellent uptake and separation of NH3 at low concentration (1000 ppm). The combination of in situ neutron powder diffraction and spectroscopic studies reveal strong, yet reversible binding interactions of NH3 to the framework oxygen sites.

17.
Nat Chem ; 16(6): 871-880, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38594366

RESUMEN

Conversion of plastic wastes to valuable carbon resources without using noble metal catalysts or external hydrogen remains a challenging task. Here we report a layered self-pillared zeolite that enables the conversion of polyethylene to gasoline with a remarkable selectivity of 99% and yields of >80% in 4 h at 240 °C. The liquid product is primarily composed of branched alkanes (selectivity of 72%), affording a high research octane number of 88.0 that is comparable to commercial gasoline (86.6). In situ inelastic neutron scattering, small-angle neutron scattering, solid-state nuclear magnetic resonance, X-ray absorption spectroscopy and isotope-labelling experiments reveal that the activation of polyethylene is promoted by the open framework tri-coordinated Al sites of the zeolite, followed by ß-scission and isomerization on Brönsted acids sites, accompanied by hydride transfer over open framework tri-coordinated Al sites through a self-supplied hydrogen pathway to yield selectivity to branched alkanes. This study shows the potential of layered zeolite materials in enabling the upcycling of plastic wastes.

18.
Nat Commun ; 15(1): 3247, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622169

RESUMEN

Photo-crosslinking polymerization stands as a fundamental pillar in the domains of chemistry, biology, and medicine. Yet, prevailing strategies heavily rely on ultraviolet/visible (UV/Vis) light to elicit in situ crosslinking. The inherent perils associated with UV radiation, namely the potential for DNA damage, coupled with the limited depth of tissue penetration exhibited by UV/Vis light, severely restrict the scope of photo-crosslinking within living organisms. Although near-infrared light has been explored as an external excitation source, enabling partial mitigation of these constraints, its penetration depth remains insufficient, particularly within bone tissues. In this study, we introduce an approach employing X-ray activation for deep-tissue hydrogel formation, surpassing all previous boundaries. Our approach harnesses a low-dose X-ray-activated persistent luminescent phosphor, triggering on demand in situ photo-crosslinking reactions and enabling the formation of hydrogels in male rats. A breakthrough of our method lies in its capability to penetrate deep even within thick bovine bone, demonstrating unmatched potential for bone penetration. By extending the reach of hydrogel formation within such formidable depths, our study represents an advancement in the field. This application of X-ray-activated polymerization enables precise and safe deep-tissue photo-crosslinking hydrogel formation, with profound implications for a multitude of disciplines.


Asunto(s)
Hidrogeles , Rayos Ultravioleta , Masculino , Animales , Bovinos , Ratas , Hidrogeles/química , Rayos X , Polimerizacion , Rayos Infrarrojos
19.
Anal Chim Acta ; 1302: 342474, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38580403

RESUMEN

BACKGROUND: N6-methyladenosine (m6A) is a common modification in RNA, crucial for various cellular functions and associated with human diseases. Quantification of m6A at single-base resolution is of great significance for exploring its biological roles and related disease research. However, existing analysis techniques, such as polymerase chain reaction (PCR) or loop-mediated isothermal amplification (LAMP), face challenges like the requirement for thermal cycling or intricate primer design. Therefore, it is urgent to establish a simple, non-thermal cycling and highly sensitive assay for m6A. RESULTS: Leveraging the inhibitory effect of m6A on primer elongation and uncomplicated feature of the isothermal exponential amplification reaction (IEXPAR), we have developed an extension-based IEXPAR (E-IEXPAR). This approach requires just a single extension primer and one template, simplifying the design process in comparison to the more complex primer requirements of the LAMP methods. The reactions are conducted at constant temperatures, therby elimiating the use of thermal cycling that needed in PCR methods. By combining IEXPAR with an extension reaction, E-IEXPAR can identify m6A in RNA concentrations as low as 4 fM. We have also introduced a new analytical model to process E-IEXPAR results, which can aid to minimize the impact of unmodified adenine (A) on m6A measurements, enabling accurate m6A quantification in small mixed samples and cellular RNA specimens. SIGNIFICANCE AND NOVELTY: E-IEXPAR streamlines m6A detection by eliminating the need for intricate primer design and thermal cycling, which are common in current analytical methods. Its utilization of an extension reaction for the initial identification of m6A, coupled with a novel calculation model tailored to E-IEXPAR outcomes, ensures accurate m6A selectivity in mixed samples. As a result, E-IEXPAR offers a reliable, straightforward, and potentially economical approach for specifically assaying m6A in both biological function studies and clinical research.


Asunto(s)
Adenosina/análogos & derivados , Técnicas de Amplificación de Ácido Nucleico , ARN , Humanos , Cartilla de ADN/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Temperatura , Sensibilidad y Especificidad
20.
Int J Biol Macromol ; 266(Pt 1): 130992, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38521318

RESUMEN

The multiscale structure, gel strength and digestibility of rice starch modified by the two-step modification of pullulanase (PUL) pretreatment and transglucosidase (TG) treatment for 6, 12, 18 and 24 h were investigated. The debranching hydrolysis of PUL produced some linear chains, which rearranged to form stable crystalline structures, reducing the digestible starch content, but weakening the gel strength. TG treatment connected some short chains to longer linear chains via α-1,6-glycosidic bonds, generating the structures of linear chain with fewer branches. The short branches promoted the interaction between starch molecules to form a more compact three-dimensional gel network structure, showing higher hardness and springiness. Moreover, these chains could form more stable crystals, reducing the digestible starch content, and the increase of branching degree inhibited digestive enzyme hydrolysis, reducing the digestion rate. The multiscale structure of starch tended to stabilize after TG treatment for 18 h, which could form a gel with stronger strength and lower digestibility than native starch gel. Therefore, the two-step modification of PUL and TG was an effective way to change the structure of rice starch to improve the gel strength and reduce the digestibility.


Asunto(s)
Geles , Glicósido Hidrolasas , Oryza , Almidón , Oryza/química , Almidón/química , Almidón/metabolismo , Glicósido Hidrolasas/metabolismo , Glicósido Hidrolasas/química , Geles/química , Hidrólisis , Digestión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...