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1.
ACS Nano ; 18(34): 23812-23822, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39146501

RESUMO

As a host for exchange bias (EB), van der Waals (vdW) magnetic materials have exhibited intriguing and distinct functionalities from conventional magnetic materials. The EB in most vdW systems is far below room temperature, which poses a challenge for practical applications. Here, by using Kerr microscopy, we demonstrate a record-high blocking temperature that approaches room temperature and a huge positive EB field that nears 2 kOe at 100 K in naturally oxidized two-dimensional (2D) vdW ferromagnetic Fe3GaTe2 nanoflakes. Moreover, we realized a reversible manipulation of both the presence/absence and positive/negative signs of EB via a training magnetic field without multiple field cooling processes. Thus, our study clearly reveals the robust, sizable, and sign-tunable EB in vdW magnetic materials up to near room temperature, thereby establishing Fe3GaTe2 as an emerging room-temperature-operating vdW material and paving the way for designing practical 2D spintronic devices.

2.
ChemSusChem ; : e202400832, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38845094

RESUMO

The performance of zinc-air battery is constrained by the sluggish rate of oxygen electrode reaction, particularly under high current discharge conditions where the kinetic process of the oxygen reduction reaction (ORR) decelerates significantly. To address this challenge, we present a novel phase transition strategy that facilitates the creation of a heteroatom-doped heterointerface (CoN/CoS2). The meticulously engineered CoN/CoS2/NC electrocatalyst displays a superior ORR half-wave potential of 0.87 V and an OER overpotential of 320 mV at 10 mA cm-2. Experimental and computational analysis confirm that the CoN/CoS2 heterostructure optimizes local charge distribution, accelerates electron transfer, and tunes active sites for enhanced catalysis. Notably, this heterojunction improves stability by resisting corrosion and degradation under harsh alkaline conditions, thus demonstrating superior performance and longevity in a custom-made liquid zinc-air battery. This research provides valuable practical and theoretical foundations for designing efficient heterointerfaces in electrocatalysis applications.

3.
Food Chem ; 452: 139553, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38733687

RESUMO

This study presents novel methodologies and materials for selectively and sensitively determining gibberellin traces in licorice to address food safety concerns. A novel hydrophilic imprinted resin-graphene oxide composite (HMIR-GO) was developed with fast mass transfer, high adsorption capacity, and exceptional aqueous recognition performance for gibberellin. Leveraging the advantages of molecular imprinting, hydrophilic resin synthesis, and rapid mass transfer characteristics of GO, HMIR-GO was employed as an adsorbent, showing resistance to matrix interference. Coupled with HPLC, a rapid and selective method for determining gibberellin was established. Under optimal conditions, the method exhibited a wide linear range (0.02-5.00 µg g-1, r = 0.9999), low detection limits (3.3 ng g-1), and satisfactory recoveries (92.0-98.4%), enabling the accurate and rapid detection of gibberellin in licorice. This study introduces a pioneering strategy for the selective extraction and determination of trace gibberellin levels, offering insights for similar applications in functional foods.


Assuntos
Giberelinas , Glycyrrhiza , Grafite , Interações Hidrofóbicas e Hidrofílicas , Impressão Molecular , Grafite/química , Glycyrrhiza/química , Giberelinas/química , Giberelinas/análise , Giberelinas/isolamento & purificação , Adsorção , Extração em Fase Sólida/métodos , Extração em Fase Sólida/instrumentação , Cromatografia Líquida de Alta Pressão , Limite de Detecção
4.
J Agric Food Chem ; 72(22): 12822-12831, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38803050

RESUMO

The identification of dietary exposure biomarkers is crucial for advancing our understanding of the health benefits of specific foods. Broccoli, a vegetable with well-known anticancer properties, contains active ingredients, such as isothiocyanates with indole side chains. Hence, indole metabolites related to broccoli consumption have the potential to serve as biomarkers of dietary exposure. In this work, we developed a new analytical method for indole metabolites in urine using a poly(deep eutectic solvents)-molecularly imprinted polymer/vinyl-functionalized graphene oxide (PDESs-MIP/VGO) in miniaturized centrifugal pipet-tip solid-phase extraction (CPT-SPE) coupled with liquid chromatography. This method integrates the strengths of PDESs-MIP/VGO, including rich adsorption interactions, high adsorption capacity, and excellent selectivity, with the simplicity and cost-effectiveness of CPT-SPE. The proposed method demonstrated low limits of quantification (1.2-2.5 ng mL-1), high accuracy (91.7-104.8%), and good precision (relative standard deviation ≤4.4%). By applying this method to analyze indole metabolites in urine, our results suggested that indole-3-carbinol and indole-3-acetonitrile have the potential to emerge as reliable dietary exposure biomarkers for broccoli intake. Furthermore, highly selective analytical methods based on molecular imprinting technology are advantageous for precise screening and analysis of dietary exposure biomarkers associated with food consumption.


Assuntos
Biomarcadores , Brassica , Indóis , Extração em Fase Sólida , Humanos , Indóis/urina , Indóis/metabolismo , Biomarcadores/urina , Brassica/química , Brassica/metabolismo , Extração em Fase Sólida/métodos , Exposição Dietética , Cromatografia Líquida de Alta Pressão/métodos , Polímeros Molecularmente Impressos/química , Polímeros Molecularmente Impressos/metabolismo , Grafite
5.
Food Chem ; 450: 139341, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-38631206

RESUMO

The escalating use of pesticides on fruits and vegetables has raised concerns about potential health risks. Therefore, we developed a superhydrophilic resin/graphene oxide (SR/GO) with rich adsorption interactions using an eco-friendly synthetic approach. SR/GO demonstrated excellent hydrophilicity, ensuring optimal contact with aqueous sample matrices. The multiple adsorption interactions, including π-π conjugation, hydrogen bonding, and electrostatic adsorption, facilitated multi-pesticide residue co-extraction. The synthesized SR/GO was applied to a miniaturized centrifugation-accelerated pipette-tip extraction method, coupled with high-performance liquid chromatography. The optimized method exhibited low consumption (15.0 mg adsorbent), and high efficiency, with low detection limits (1.4-2.9 ng g-1) and high recoveries (75.3-113.0%). Water-compatible SR/GO, along with a miniaturized extraction process, showcases a potent analytical approach for pesticide residue analysis in fruits and vegetables. The significance of this method lies in its ability to ensure agricultural and food safety by using a low-cost and efficient multi-pesticide residue analytical strategy.


Assuntos
Frutas , Verduras , Interações Hidrofóbicas e Hidrofílicas , Grafite/química , Resíduos de Praguicidas/química , Frutas/química , Verduras/química , Pyrus/química , Citrullus/química , Solanum lycopersicum/química , Malus/química , Cucurbita/química , Cromatografia Líquida de Alta Pressão
6.
J Med Chem ; 67(9): 7033-7047, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38634331

RESUMO

A brand-new enhanced starvation is put forward to trigger sensitized chemotherapy: blocking tumor-relation blood vessel formation and accelerating nutrient degradation and efflux. Following this concept, two cisplatin-like gemfibrozil-derived Pt(IV) prodrugs, GP and GPG, are synthesized. GP and GPG had nanomolar IC50 against A2780 cells and higher selectivity against normal cells than cisplatin. Bioactivity results confirmed that GP and GPG highly accumulated in cells and induced DNA damage, G2-phase arrest, and p53 expression. Besides, they could increase ROS and MDA levels and reduce mitochondrial membrane potential and Bcl-2 expression to promote cell apoptosis. In vivo, GP showed superior antitumor activity in A2780 tumor-bearing mice with no observable tissue damage. Mechanistic studies suggested that highly selective chemotherapy could be due to the new enhanced starvation effect: blocking vasculature formation via inhibiting the CYP2C8/EETs pathway and VEGFR2, NF-κB, and COX-2 expression and cholesterol efflux and degradation acceleration via increasing ABCA1 and PPARα.


Assuntos
Antineoplásicos , Genfibrozila , Animais , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Genfibrozila/farmacologia , Camundongos Endogâmicos BALB C , Compostos Organoplatínicos/farmacologia , Compostos Organoplatínicos/química , Pró-Fármacos/farmacologia , Pró-Fármacos/química , Pró-Fármacos/síntese química
7.
J Food Sci ; 89(5): 2672-2683, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38602052

RESUMO

In this study, the polysaccharide (RHCP) extracted from Houttuynia cordata rhizome was acetylated through the acetic anhydride method. The physicochemical properties of RHCP and its acetylated derivatives (Ac-RHCP) were determined by infrared spectra, scanning electron microscopy, and Congo red test. Meanwhile, the α-glucosidase inhibition mechanism of RHCP and Ac-RHCP was analyzed by inhibition kinetics, and circular dichroism and fluorescence spectroscopy. Ac-RHCP resulted in a more porous surface structure and 1.83-fold higher solubility compared with RHCP. At a concentration of 6 mg/mL, the α-glucosidase inhibition rate of Ac-RHCP was 75.40%, while that of RHCP was 44.68%. RHCP and Ac-RHCP inhibited α-glucosidase in a mixed-type manner, reduced the endogenous fluorescence of α-glucosidase, affected the microenvironment of amino acid residues, and changed the conformation of α-glucosidase. The study indicates that Ac-RHCP exhibits a certain level of α-glucosidase inhibition, demonstrating its potential as a functional food for glycemic control.


Assuntos
Inibidores de Glicosídeo Hidrolases , Houttuynia , Polissacarídeos , Rizoma , alfa-Glucosidases , Inibidores de Glicosídeo Hidrolases/farmacologia , Rizoma/química , alfa-Glucosidases/metabolismo , Houttuynia/química , Acetilação , Polissacarídeos/química , Polissacarídeos/farmacologia , Cinética , Dicroísmo Circular , Solubilidade , Espectrometria de Fluorescência
8.
J Chromatogr A ; 1715: 464599, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38150874

RESUMO

Overweight and obesity are the causes of many diseases and have become global "epidemics". Research on natural active components with anti-adipogenesis effects in plants has aroused the interest of researchers. One of the most critical problems is establishing sample preparation and analytical techniques for quickly and selectively extracting and determining the active anti-adipogenesis components in complex plant matrices for developing new anti-adipogenic drugs. In this study, a new poly(deep eutectic solvents) surface imprinted graphene oxide composite (PDESs-MIP/GO) with high selectivity for phenolic acids was prepared using deep eutectic solvents as monomers and crosslinkers. A miniaturized centrifugation-accelerated pipette-tip matrix solid-phase dispersion method (CPT-MSPD) with PDESs-MIP/GO as adsorbent, coupled with high-performance liquid chromatography, was further developed for the rapid determination of anti-adipogenesis markers in Solidago decurrens Lour. (SDL). The established method was successfully used to determination anti-adipogenesis markers in SDL from different regions, with the advantages of accuracy (recoveries: 94.4 - 115.9 %, RSDs ≤ 9.8 %), speed (CPT-MSPD time: 11 min), selectivity (imprinting factor: ∼2.0), and economy (2 mg of adsorbent and 1 mL of solvents), which is in line with the current advanced principle of "3S+2A" in analytical chemistry.


Assuntos
Solventes Eutéticos Profundos , Grafite , Solidago , Extração em Fase Sólida/métodos , Solventes/química , Cromatografia Líquida de Alta Pressão
9.
Food Chem X ; 20: 100897, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38144783

RESUMO

Edible chrysanthemum is a common food resource for tea and functional foods with potential benefits for human health. Studies have indicated that chrysanthemum has the potential effect on inflammatory diseases, while the effects on gouty inflammation remain underexplored. The present study aimed to investigate the anti-gout activity and characterize the active ingredients of chrysanthemums by using metabolite profiles, in vitro experiments, and spectrum-effect analysis. Results showed that 'Boju' (BJ), 'Hangbaiju' (HBJ), and 'Huaiju' (HJ) exhibited regulatory effects on monosodium urate (MSU)-induced inflammation. At the dose of 50 µg/mL, the inhibitory rates of IL-1ß secretion were 24.53 %, 14.36 %, and 38.10 %, respectively. A total of 32 phenolic compounds were identified or preliminarily assigned in UPLC-Q/TOF-MS analysis. And seven phenolics related to anti-gout activity were identified by spectrum-effect relationships. According to ADME (absorption, distribution, metabolism, excretion) evaluation and experiments verification, luteolin, acacetin-7-O-glucoside, and apigenin-7-O-glucoside were critical constituents potentially associated with the reduction of inflammation in gout. Additionally, these phenolics might be suitable as quality control indicators. This study clarified the anti-gout properties of different cultivars of chrysanthemums and active compounds, providing a theoretical basis for its scientific utilization in functional foods.

10.
J Phys Chem Lett ; 14(43): 9624-9632, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37870322

RESUMO

The revelation of the underlying structure-property relationship of single-atom catalysts (SACs) is a fundamental issue in the oxygen reduction reaction (ORR). Here we present systematic theoretical and experimental investigations of various N-doped graphdiyne (NGDY) supported transition metals (TMs) to shed light on this relationship. Calculation results indicate that the TMs' comprehensive activities follow the order of Pd@NGDY > Ni@NGDY > Co@NGDY > Fe@NGDY, which fits well with our experimental conclusion. Moreover, detailed structure-property relationship (194 in total) analysis suggests that the key-species binding stability (ΔG*OH), the d-orbital center (εd/εd-a) and charge transfer (ΔQTM/ΔQTM-a) of the active metal before/after reactants adsorption and the bond length of TM-O (LTM-O) as descriptors can well reflect the intermediate binding stability or ORR activity on different TM-SACs. Specifically, the change trend of catalytic activity is opposite to that of intermediate binding stability, meaning that too strongly bonded *OOH, *O, and *OH intermediates are unfavorable for ORR.

11.
J Chromatogr A ; 1705: 464224, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37490816

RESUMO

Osimertinib (OSIM) is widely used as a mainstream drug for the treatment of non-small cell lung cancer (NSCLC). However, the lack of a rapid extraction and detection method for OSIM and its metabolite, AZ-5104, has limited clinical drug metabolism and drug resistance research because the drug is unstable. In this study, a new ionic liquid hybrid hierarchical porous material (IL-HHPM) was synthesized with hierarchical porous structures, including micropores (1.6-2.0 nm), mesopores (2.0-50.0 nm), macropores (50.0-148.7 nm), and multiple functional groups via a one-step hydrothermal method using silanized ionic liquids (IL) as functionalized hybrid monomer. The IL-HHPM has the advantages of a high specific surface area (437.4 ± 4.6 m2 g-1), sizable pore volume (0.74 cm3 g-1), and fast mass transfer, additionally, the IL-HHPM adsorbed OSIM and AZ-5104 via π-π interactions and hydrogen bonding. OSIM and AZ-5104 were rapidly extracted and measured in human urine using rapid and miniaturized centrifugal spin-column extraction (MCSCE), which was based on the IL-HHPM. The optimized factors for the extraction recoveries of OSIM and AZ-5104 were adsorbent dosage (8.0 mg), sample volume (0.5 mL), and operation time (9.0 min), and markedly reduced the adsorbent dosage and operation time. The IL-HHPM-MCSCE-HPLC method displayed good linearity (0.02-5.00 µg mL-1, r ≥ 0.9997), satisfying accuracy (spiked recoveries of 87.7%-100.0%), and good precision (RSDs ≤ 7.0%). The developed method is rapid, sensitive, and reproducible for the simultaneous determination of trace level of OSIM and AZ-5104 in human urine.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Líquidos Iônicos , Neoplasias Pulmonares , Humanos , Líquidos Iônicos/química , Porosidade , Cromatografia Líquida de Alta Pressão/métodos , Extração em Fase Sólida/métodos
12.
Nanomaterials (Basel) ; 13(13)2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37446461

RESUMO

As a key role in hindering the large-scale application of fuel cells, oxygen reduction reaction has always been a hot issue and nodus. Aiming to explore state-of-art electrocatalysts, this paper reviews the latest development of nonmetallic catalysts in oxygen reduction reactions, including single atoms doped with carbon materials such as N, B, P or S and multi-doped carbon materials. Afterward, the remaining challenges and research directions of carbon-based nonmetallic catalysts are prospected.

13.
Probiotics Antimicrob Proteins ; 15(6): 1529-1538, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36376613

RESUMO

Based on the adhesion and surface properties of Lactobacillus acidophilus NCFM, five common polyphenols in fruits and vegetables, including resveratrol, epicatechin, quercetin, hesperidin, and caffeic acid, were screened, and the reasons for resveratrol promoting adhesion were systematically explained. The results showed that resveratrol could significantly enhance NCFM adhesion to mucin (1.73 fold), followed by epicatechin (1.47 fold), caffeic acid (1.30 fold), and hesperidin (0.99 fold), while quercetin had a certain degree of inhibition (0.84 fold). The effects of these polyphenols on surface hydrophobicity and auto-aggregation of NCFM were consistent with adhesion results. Then, how resveratrol promotes NCFM adhesion was further explored. The results of the proteomic analysis showed that resveratrol changed the surface layer proteins of NCFM, involving 4 up-regulated proteins and 12 down-regulated proteins. In addition, resveratrol promoted the expression of mucin genes and the glycosylation of mucins on the HT-29 cell surface. Our results indicate that resveratrol changes the surface layer proteins of NCFM to modify surface properties and adhere to mucins. Meanwhile, resveratrol promotes expression and glycosylation of mucins in HT-29 cells. Our findings provide theoretical support for an in-depth explanation of the interaction among resveratrol, NCFM, and the HT-29 cells.


Assuntos
Catequina , Hesperidina , Humanos , Resveratrol/farmacologia , Resveratrol/metabolismo , Lactobacillus acidophilus/fisiologia , Aderência Bacteriana , Catequina/farmacologia , Hesperidina/metabolismo , Hesperidina/farmacologia , Proteômica , Quercetina/farmacologia , Quercetina/metabolismo , Polifenóis/metabolismo , Polifenóis/farmacologia , Mucinas/metabolismo
14.
Phys Chem Chem Phys ; 24(48): 29279-29297, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36268731

RESUMO

From the overall framework of battery development, the battery structures have not received enough attention compared to the chemical components in batteries. The mechanical-electrochemical coupling behavior is a starting point for investigation on battery structures and the subsequent battery design. This perspective systematically reviews the efforts on the mechanics-based design for lithium-ion batteries (LIBs). Two typical types of mechanics-based LIB designs, namely the design at the preparation stage and that at the cycling stage, have been discussed, respectively. The former systemizes the structure design of multiscale battery components from the particle level to the cell level. The latter focuses on the external mechanics-related control, including external pressures and charge-discharge protocols, of in-service LIBs. Moreover, the general problems currently being faced in the mechanics-based LIB design are summarized, followed by the outlook of possible solutions.

15.
J Pharm Anal ; 12(2): 301-307, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35582392

RESUMO

Indole-3-carbinol (I3C), an important anticancer compound found in broccoli, has attracted considerable attention. The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challenging as I3C is unstable at low pH and high temperature. In this study, a rapid, accurate, and low-cost ultrasound-assisted dispersive-filter extraction (UADFE) technique based on poly(deep eutectic solvent)-graphene oxide (PDES-GO) adsorbent was developed for the isolation and analysis of I3C in broccoli for the first time. PDES-GO with multiple adsorption interactions and a fast mass transfer rate was synthesized to accelerate adsorption and desorption. UADFE was developed by combining dispersive solid-phase extraction (DSPE) and filter solid-phase extraction (FSPE) to realize rapid extraction and separation. Based on the above two strategies, the proposed PDES-GO-UADFE method coupled with high-performance liquid chromatography (HPLC) allowed the rapid (15-16 min), accurate (84.3%-96.4%), and low-cost (adsorbent: 3.00 mg) analysis of I3C in broccoli and was superior to solid-phase extraction, DSPE, and FSPE methods. The proposed method showed remarkable linearity (r=0.9998; range: 0.0840-48.0 µg/g), low limit of quantification (0.0840 µg/g), and high precision (relative standard deviation ≤5.6%). Therefore, the PDES-GO-UADFE-HPLC method shows significant potential in the field of pharmaceutical analysis for the separation and analysis of anti-cancer compounds in complex plant samples.

16.
Front Nutr ; 9: 878725, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35479744

RESUMO

In this study, carboxymethyl cellulose (CMC) was added to soybean protein isolate (SPI)-stabilized rice bran oil (RBO) emulsion to improve its physicochemical stability and free fatty acid (FFA) release characteristics. RBO emulsions stabilized by SPI and various contents of CMC were prepared and assessed by measuring zeta potential, particle size, transmission, and microstructure, the rheological properties were analyzed by dynamic shear rheometer. In addition, its chemical stability was characterized by a storage experiment, and the FFA release was explored by a simulated gastrointestinal tract (GIT) model. It showed that the negative charge of the droplets of RBO emulsion was increased with increasing CMC content. The decrease in transmission of SPI-stabilized RBO emulsion with increasing CMC content was due to the droplets not being free to move by the special network interaction and an increase in the viscosity. According to the determination of the reactive substances of lipid hydroperoxide and thiobarbituric acid during 30 days storage at 37°C, the chemical stability of the emulsion added with CMC was enhanced compared with the SPI-stabilized RBO emulsion. In-vitro digestion studies not only evaluated the structural changes of RBO emulsions at different stages, but also found that RBO emulsion with CMC showed a higher level of free fatty acids release in comparison with that without CMC. It indicated that the utilization of CMC can improve the bioavailability of RBO emulsions.

17.
Molecules ; 27(7)2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35408645

RESUMO

The Fe(III)-S(IV) system used for advanced oxidation processes (AOPs) at acidic pH has just been proposed and demonstrated valid for very few contaminants in the last several years. In this work, we investigated the effect of ultraviolet A (UVA) radiation on the degradation efficiency of the Fe(III)/S(IV) system at near-neutral pH. Paracetamol (PARA) was selected as a model contaminant. The influencing factors, such as initial pH and Fe(III)/S(IV) molar ratio on chemical kinetics, and the mechanism of PARA degradation are investigated, with an emphasis on the determination of dominant oxidant species. Our results show that irradiation enhances the PARA degradation by accelerating the decrease of pH to acidic levels, and the optimal pH for the degradation of PARA in the Fe(III)/S(IV)/O2 system was around 4.0. At near-neutral pH, more than 60% of PARA was decomposed within 40 min under irradiation, whereas no significant degradation of PARA was observed using Fe(III)/S(IV) at pH 7.0 without irradiation. Mechanism investigation revealed that sulfate radical (SO4•‒) is the main oxidant species generated and responsible for the PARA degradation under these conditions. This finding may have promising implications in developing a new degradation process for dealing with wastewater at near-neutral pH by the Fe(III)/S(IV)/O2 system under UVA irradiation.


Assuntos
Acetaminofen , Poluentes Químicos da Água , Ferro , Oxidantes , Oxirredução , Sulfitos , Poluentes Químicos da Água/análise
18.
Biomech Model Mechanobiol ; 20(5): 2013-2030, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34309757

RESUMO

Osteoporosis (OP), a skeletal disease making bone mechanically deteriorate and easily fracture, is a global public health issue due to its high prevalence. It has been well recognized that besides bone loss, microarchitecture degradation plays a crucial role in the mechanical deterioration of OP bones, but the specific role of microarchitecture in OP has not been well clarified and quantified from mechanics perspective. Here, we successfully decoupled and identified the specific roles of microarchitecture, bone mass and tissue property in the failure properties of cancellous bones, through µCT-based digital modeling and finite element method simulations on bone samples from healthy and ovariectomy-induced osteoporotic mice. The results show that the microarchitecture of healthy bones exhibits longitudinal superiority in mechanical properties such as the effective stiffness, strength and toughness, which fits them well to bearing loads along their longitudinal direction. OP does not only reduce bone mass but also impair the microarchitecture topology. The former is mainly responsible for the mechanical degradation of bones in magnitude, wherever the latter accounts for the breakdown of their function-favorable anisotropy, the longitudinal superiority. Hence, we identified the microarchitecture-deterioration-induced directional mismatch between material and loading as a hazardous feature of OP and defined a longitudinal superiority index as measurement of the health status of bone microarchitecture. These findings provide useful insights and guidelines for OP diagnosis and treat assessment.


Assuntos
Osso Esponjoso/fisiopatologia , Vértebras Lombares/fisiopatologia , Osteoporose/fisiopatologia , Animais , Osso e Ossos , Feminino , Análise de Elementos Finitos , Imageamento Tridimensional , Camundongos , Camundongos Endogâmicos BALB C , Fraturas por Osteoporose/fisiopatologia , Porosidade , Pressão , Estresse Mecânico , Microtomografia por Raio-X/métodos
19.
Food Chem ; 349: 128982, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33561797

RESUMO

This paper reports a selective, sensitive, and miniaturized analytical method based on a molecularly imprinted graphene oxide (MIP-GO) composite as adsorbent for miniaturized tip solid-phase extraction (MTSPE) to determine naphthalene-derived plant growth regulators (PGRs) in apples. The proposed method combines the advantages of MIP-GOs (high selectivity), MTSPE (low consumption), and high-performance liquid chromatography-fluorescence detection (high sensitivity). Under optimized conditions, the method exhibited appreciable linearity (2.00-200 ng/g), low detection limits (0.21-0.53 ng/g), high accuracy (absolute recoveries: 87.6-99.5%), and high precision (relative standard deviations ≤ 3.0%), along with low consumption (0.5 mL sample solution and 2.0 mg adsorbent). In addition, the adsorption performance of the MIP-GO adsorbent did not decrease over ten months, highlighting the long storage and operational lifetime of the adsorbent. The proposed method was employed for the analysis of naphthalene-derived PGR residues in apples and exhibited promising potential for application in food safety analysis.


Assuntos
Análise de Alimentos/métodos , Grafite/química , Malus/química , Impressão Molecular , Naftalenos/química , Reguladores de Crescimento de Plantas/análise , Reguladores de Crescimento de Plantas/química , Adsorção , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Extração em Fase Sólida/métodos , Fatores de Tempo
20.
Food Chem ; 337: 127752, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32777573

RESUMO

The Chinese Yam (Dioscorea opposita) is cultivated widely in China. However, there are potential safety risks associated with herbicide residues in Chinese Yam because of its characteristics and unregulated use of pesticides. We developed an efficient sample preparation technique for simultaneous analysis of atrazine and its degradation products in Chinese Yam using accelerated solvent extraction and pipette tip solid-phase extraction followed by UPLC-DAD analysis. Molecularly imprinted polymer (MIP) were used as the adsorbent material. Method performance was evaluated and our results showed the limit of quantification was 1-3 µg/ kg, with recoveries in the range 79.2-103.8%. When compared with other methods, this method provided superior performance in terms of sensitivity, accuracy, and precision. This method is, therefore, expected to be useful in supervised residue analysis.


Assuntos
Atrazina/análise , Atrazina/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Dioscorea/química , Extração em Fase Sólida/métodos , Adsorção , Atrazina/química , Impressão Molecular , Polímeros/síntese química , Polímeros/química , Solventes/química
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