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1.
Food Chem ; 455: 139873, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38850987

RESUMO

The kind of compounding emulsifier used and the amount of compounding have a significant impact on the emulsion's stability. In this study, the average particle size, Zeta potential, emulsification index, laser confocal microstructure, and rheological properties shows that the ratio of monoglyceride-xanthan gum and sucrose ester-xanthan gum could maintain the good stability of the emulsion in a certain range, and the monoglyceride and sucrose ester compounding could effectively improve the stability of the emulsion in a specific ratio (7:3). The results of fluorescence spectroscopy, Fourier transform infrared spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that the simultaneous complexation of three substances was more likely to produce hydrophobic interactions with walnut proteins than the simultaneous complexation of two substances. Also confirmed were the hydrogen bonding connections between the proteins and the monoglyceride, sucrose ester, and xanthan gum. Monoglyceride and xanthan gum complexes were also found to stabilize more proteins.


Assuntos
Emulsificantes , Emulsões , Juglans , Polissacarídeos Bacterianos , Polissacarídeos Bacterianos/química , Emulsificantes/química , Juglans/química , Emulsões/química , Tamanho da Partícula , Leite/química , Reologia , Interações Hidrofóbicas e Hidrofílicas , Animais
2.
Foods ; 13(10)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38790813

RESUMO

Walnuts are high in protein content and rich in nutrients and are susceptible to oxidation during production and processing, leading to a decrease in the stability of walnut protein emulsions. In this paper, the effect of alkyl peroxyl radical oxidation on the stability of walnut protein emulsions is investigated. With the increase of 2,2-azobis (2-methylpropionamidine) dihydrochloride (AAPH) concentration, both its protein and fat were oxidized to different degrees, and the droplets of the emulsion were first dispersed and then aggregated as seen from the laser confocal, and the stability of walnut protein emulsion was best at the AAPH concentration of 0.2 mmol/L. In addition to this, the adsorption rate of adsorbed proteins showed a decreasing and then an increasing trend with the increase in the oxidized concentration. The results showed that moderate oxidation (AAPH concentration: 0-0.2 mmol/L) promoted an increase in protein flexibility and a decrease in the protein interfacial tension, leading to the decrease in emulsion droplet size and the increase of walnut protein emulsion stability, and excessive oxidation (AAPH concentration: 1-25 mmmol/L) weakened protein flexibility and electrostatic repulsion, making the walnut protein emulsion less stable. The results of this study provide theoretical references for the quality control of walnut protein emulsions.

3.
Int J Biol Macromol ; 261(Pt 1): 129795, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38290641

RESUMO

The stability of food emulsions is the basis for other properties. During their production and processing, emulsions tend to become unstable due to their thermodynamic instability, and it is usually necessary to add emulsifiers and proteins to stabilize emulsions. It becomes crucial to study the intrinsic mechanisms of emulsifiers and proteins and their joint stabilization of food emulsions. This paper summarizes the research on intrinsic mechanisms of food emulsions stabilized by emulsifiers and proteins in recent years. The destabilization and stabilization of emulsions are related to the added surfactants. The properties, type, and concentration of emulsifiers determine the stability of emulsions, and the emulsifiers can be classified into different types (e.g., ionic or nonionic, solid or liquid) according to their properties and sources. The physicochemical properties of proteins (e.g., spatial conformation, hydrophobicity) and the composition of proteins can also determine the stability of emulsions, and emulsions stabilized by emulsifiers and proteins together not only depend on these factors but also have a great relationship with the mutual combination and competition between the two. The instability and stability of emulsions are related to factors such as interfacial interaction forces, the rheological nature of the interface, and the added surfactant.


Assuntos
Emulsificantes , Proteínas , Emulsões/química , Emulsificantes/química , Proteínas/química , Tensoativos , Alimentos
4.
J Sci Food Agric ; 104(4): 1909-1919, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-37884470

RESUMO

BACKGROUND: Single emulsifiers have an effect on the stability of plant protein drinks, giving some improvement. Emulsifiers are more effective in maintaining emulsion stability when combined with polysaccharides such as xanthan gum. In this paper, we studied the food-grade emulsifier sucrose ester and measured the average particle size, polydispersity value, zeta potential, microrheological properties, microstructure and creaming index related to walnut protein emulsion by constructing a walnut protein emulsion simulation system. SDS-PAGE and low-field NMR were used to analyze the relative molecular masses of emulsions and the water distribution of emulsions, respectively, to further investigate the synergistic effects of sucrose esters and xanthan gum on the ease of emulsification and intrinsic mechanisms of different molecular weight proteins of walnut protein emulsions. RESULTS: The results indicate that the synergistic effect of sucrose esters and xanthan gum was to stabilize emulsions better than single emulsifiers. Xanthan gum and protein may form protein-polysaccharide complexes, as well as the hydrophobic interaction between sucrose ester and xanthan gum. The properties of xanthan gum can improve the stability of the emulsion by affecting the mechanical properties of walnut protein emulsion, and the combination of sucrose ester and xanthan gum can better stabilize large protein molecules. CONCLUSION: The results not only provide a theoretical basis for the stability of plant protein emulsion systems, but also provide technical support for the production and processing of large-molecule plant proteins into emulsions in this field for improving their stability, and also provide more possibilities for other types of emulsions. © 2023 Society of Chemical Industry.


Assuntos
Juglans , Emulsificantes/química , Emulsões/química , Juglans/química , Proteínas de Plantas , Polissacarídeos Bacterianos/química , Reologia , Sacarose
5.
J Nanobiotechnology ; 21(1): 474, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072979

RESUMO

Copper-based antibacterial materials have emerged as a potential alternative for combating bacterial infections, which continue to pose significant health risks. Nevertheless, the use of copper-based nanoparticles as antibacterial agents has faced challenges due to their toxicity towards cells and tissues. To overcome this obstacle, we propose a new approach using a contact-active copper-based nanoparticles called polydopamine (PDA)-coated copper-amine (Cuf-TMB@PDA). The positively charged surface of Cuf-TMB@PDA enables efficient targeting of negatively charged bacteria, allowing controlled release of Cu(II) into the bacterial cell membrane. Moreover, Cuf-TMB@PDA exhibits similar ·OH signals as Cuf-TMB suspensions in previous work. In cytotoxicity assays conducted over 72 h, Cuf-TMB@PDA demonstrated an efficacy of 98.56%, while releasing lower levels of Cu(II) that were less harmful to cells, resulting in enhanced antimicrobial effects. These antimicrobial properties are attributed to the synergistic effects of charge-contact activity of PDA, controlled release of Cu(II), and free radicals. Subsequent in vivo experiments confirmed the strong antimicrobial potency of Cuf-TMB@PDA and its ability to promote wound healing.


Assuntos
Cobre , Nanopartículas , Cobre/farmacologia , Preparações de Ação Retardada/farmacologia , Antibacterianos/farmacologia , Cicatrização , Formiatos/farmacologia
6.
ACS Appl Mater Interfaces ; 15(37): 43431-43440, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37674322

RESUMO

Fenton-like radical processes are widely utilized to explain catalytic mechanisms of peroxidase-like nanozymes, which exhibit remarkable catalytic activity, cost-effectiveness, and stability. However, there is still a need for a comprehensive understanding of the formation, stabilization, and transformation of such radicals. Herein, a copper formate-based nanozyme (Cuf-TMB) was fabricated via a pre-catalytic strategy under ambient conditions. The as-prepared nanozyme shows comparable catalytic activity (Km, 1.02 × 10-5 mM-1; Kcat, 3.09 × 10-2 s-1) and kinetics to those of natural peroxidase toward H2O2 decomposition. This is attributed to the feasible oxidation by *OH species via the *O intermediate, as indicated by density functional theory calculations. The key ·OH radicals were detected to be stable for over 52 days and can be released in a controlled manner during the catalytic process via in situ electron spin-resonance spectroscopy measurements. Based on the understanding, an ultrasensitive biosensing platform was constructed for the sensitive monitoring of biochemical indicators in clinic settings.


Assuntos
Cobre , Peróxido de Hidrogênio , Preparações de Ação Retardada , Formiatos , Peroxidase , Peroxidases , Corantes
7.
J Sci Food Agric ; 103(14): 6995-7005, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37311725

RESUMO

BACKGROUND: Walnut kernels are high in polyphenols (PPs), which cause low protein solubility, limiting the use of walnut protein in the food industry. To obtain the best technical parameters of the dephenolization treatment, the defatted walnut powder was dephenolized using ultrasound-assisted ethanol extraction (UAE), and the response surface optimization was performed on the basis of single factor. On this basis, the effects of dephenolization on the solubility, emulsifying properties and foaming properties of walnut protein isolates (WPIs) were compared to those of defatted walnut powder without dephenolization. RESULTS: The results showed that PP extraction in the UAE could significantly increase PP yield. The optimal process parameters were as follows: 51% (v/v) ethanol concentration, 140 W ultrasound power, 10 min extraction time, 30 °C ultrasound temperature, and a material-liquid ratio of 1:30 (w/v). The results revealed that the UAE dephenolization treatment significantly improved the functionality of WPI and that the functionality of the dephenolized WPI by UAE was superior to that of the protein without dephenolization, and that the functionality of both walnut proteins was the worst at pH 5, with solubility of 5.31% and 4.86%, emulsifying activity index (EAI) of 24.95 and 19.91 m2 /g, and foaming capacity (FC) of 3.66% and 2.94%, respectively; and the best at pH 11, with solubility of 82.35% and 73.55%, EAI of 46.35 and 37.28 m2 /g, and FC of 35.85% and 18.87%, respectively. CONCLUSION: The study found that dephenolization by UAE can significantly improve the functionality of WPI, and this method should be promoted and used in walnut and walnut protein processing industries. © 2023 Society of Chemical Industry.


Assuntos
Juglans , Polifenóis , Polifenóis/química , Juglans/química , Pós/análise , Etanol/análise , Nozes/química
8.
Int J Biol Macromol ; 241: 124102, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-36958445

RESUMO

It is one of the most emergent challenges to prepare wound dressings for quickly and effectively controlling profuse bleeding in clinical surgery and emergent accident. In this work, a novel strategy has been developed to prepare methacrylated gelatin-dopamine (GelMA-DA)/quaternized chitosan (QCS)/glycerol (Gly) composite sponges with good biocompatibility, tissue self-adhesion, antibacterial activity, and hemostatic ability. Results show that the GelMA-DA/QCS/Gly sponges display good biocompatibility and water absorption capacity. The lap shear strength of the GelMA-DA/QCS/Gly sponge with the GelMA-DA content of 5 W/V% is approximately 128.36 ± 8.45, 125.17 ± 7.18, 138.29 ± 7.94, and 113.83 ± 9.28 kPa for skin, liver, muscle, and fat, respectively. The GelMA-DA/QCS/Gly sponge displays better antibacterial activity against Gram positive and negative bacteria than the commercial Gelatin hemostatic sponge and CS hemostatic sponge. Animal experiments using rat tail and liver bleeding model show that the hemostasis time and blood loss in the GelMA-DA/QCS/Gly sponge group is approximately 33.3 ± 6.7 s and 0.19 ± 0.05 g, respectively, which is also better than that of the commercial Gelatin hemostatic sponge and CS hemostatic sponge. These results demonstrate promising potential of the GelMA-DA/QCS/Gly sponges for applications as hemostatic wound dressings in clinical surgery and emergent treatment.


Assuntos
Quitosana , Hemostáticos , Ratos , Animais , Hemostáticos/farmacologia , Quitosana/farmacologia , Gelatina/farmacologia , Glicerol/farmacologia , Dopamina/farmacologia , Hemostasia , Hemorragia/tratamento farmacológico , Bandagens , Antibacterianos/farmacologia
9.
Foods ; 12(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36766154

RESUMO

Walnuts are rich in fat and proteins that become oxidized during the processing and storage conditions of their kernels. In this study, the effect of three packaging materials (e.g., polyethylene sealed packaging, polyamide/polyethylene vacuum packaging, and polyethylene terephthalate/aluminum foil/polyethylene vacuum packaging) were investigated on the oxidation, structural and digestive properties of walnut kernel proteins. Results showed that the amino acid content gradually decreased and carbonyl derivatives and dityrosine were formed during storage. The protein molecule structure became disordered as the α-helix decreased and the random coil increased. The endogenous fluorescence intensity decreased and the maximum fluorescence value was blue-shifted. After 15 days of storage, surface hydrophobicity decreased, while SDS-PAGE and HPLC indicated the formation of large protein aggregates, leading to a reduction in solubility. By simulating gastrointestinal digestion, we found that oxidation adversely affected the digestive properties of walnut protein isolate and protein digestibility was best for polyethylene terephthalate/aluminum foil/polyethylene vacuum packaging. The degree of protein oxidation in walnuts increased during storage, which showed that except for fat oxidation, the effect of protein oxidation on quality should be considered. The results of the study provided new ideas and methods for walnut quality control.

10.
Molecules ; 27(23)2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36500518

RESUMO

Walnut protein isolate (WPI) was hydrolyzed using Alcalase for 0, 30, 60, 90, 120 and 150 min to investigate the effect of different hydrolysis times on the structure and antioxidant properties of walnut proteins. The identified peptides HADMVFY, NHCQYYL, NLFHKRP and PSYQPTP were used to investigate the structure-activity relationship by using LC-MS/MS and molecular docking. The kinetic equations DH = 3.72ln [1 + (6.68 E0/S0 + 0.08) t] were developed and validated to explore the mechanism of WIP hydrolysis by Alcalase. Structural characteristics showed that the UV fluorescence intensity and endogenous fluorescence intensity of the hydrolysates were significantly higher than those of the control. FTIR results suggested that the secondary structure gradually shifted from an ordered to a disordered structure. Enzymatic hydrolysis containing much smaller molecule peptides than WPI was observed by molecular weight distribution. In vitro, an antioxidant test indicated that Alcalase protease hydrolysis at 120 min showed more potent antioxidant activity than hydrolysates at other hydrolysis times. In addition, four new antioxidant peptides were identified by LC-MS/MS. Molecular docking indicated that these peptides could interact with ABTS through interactions such as hydrogen bonding and hydrophobic interactions. Thus, WPI hydrolysates could be used as potential antioxidants in the food and pharmaceutical industries.


Assuntos
Juglans , Hidrolisados de Proteína , Hidrolisados de Proteína/química , Juglans/química , Antioxidantes/química , Simulação de Acoplamento Molecular , Cromatografia Líquida , Espectrometria de Massas em Tandem , Peptídeos/química , Hidrólise , Subtilisinas
11.
Foods ; 11(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36553844

RESUMO

Walnut protein is a key plant protein resource due to its high nutritional value, but walnuts are prone to oxidation during storage and processing. This article explored the oxidative modification and digestion mechanism of walnut protein isolates by peroxyl radical and obtained new findings. SDS-PAGE and spectral analysis were used to identify structural changes in the protein after oxidative modification, and LC-MS/MS was used to identify the digestion products. The findings demonstrated that as the AAPH concentration increased, protein carbonyl content increased from 2.36 to 5.12 nmol/mg, while free sulfhydryl content, free amino content, and surface hydrophobicity decreased from 4.30 nmol/mg, 1.47 µmol/mg, and 167.92 to 1.72 nmol/mg, 1.13 µmol/mg, and 40.93 nmol/mg, respectively. Furthermore, the result of Tricine-SDS-PAGE in vitro digestion revealed that protein oxidation could cause gastric digestion resistance and a tendency for intestinal digestion promotion. Carbonyl content increased dramatically during the early stages of gastric digestion and again after 90 min of intestine digestion, and LC-MS/MS identified the last digestive products of the stomach and intestine as essential seed storage proteins. Oxidation causes walnut proteins to form aggregates, which are then re-oxidized during digestion, and proper oxidative modification may benefit intestinal digestion.

12.
Macromol Biosci ; 22(12): e2200321, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36057971

RESUMO

Poly (ether-ether-ketone) (PEEK) displays promising potential application in bone tissue repair and orthopedic surgery due to its good biocompatibility and chemical stability. However, the bio-inertness and poor mechanical strength of PEEK greatly limit its application in load-bearing bones. In this study, calcium silicate whiskers (CSws) are synthesized and then compounded with PEEK to fabricate the PEEK/CSw composites with excellent mechanical properties, biological activity. Compared with PEEK, the PEEK/CSw composites exhibited higher hydrophilicity and ability to deposit hydroxyapatite on the surface. CSws are evenly dispersed in the PEEK matrix at 10 wt% content and the mechanical strength of the PEEK/CSw composite is ≈96.9 ± 2.4 MPa, 136.3 ± 2.4 MPa, and 266.0 ± 3.2 MPa, corresponding to tensile strength, compressive strength, and bending strength, respectively, which is 20%, 18%, and 52% higher than that of pure PEEK. The composites improve the adhesion, proliferation, and osteogenic differentiation of BMSCs. Furthermore, PEEK/CSw composite remarkably improves bone formation and osteointegration, which has higher bone repair capacity than PEEK. These results demonstrate that the PEEK/CSw scaffolds display superior abilities to integrate with the host bone and promising potential in the field of load bearing bone repair.


Assuntos
Cetonas , Osteogênese , Animais , Cetonas/farmacologia , Cetonas/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química , Éter , Polietilenoglicóis/farmacologia , Polietilenoglicóis/química , Vibrissas , Éteres
13.
RSC Adv ; 12(36): 23637-23643, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-36090414

RESUMO

A nature-inspired strategy has been developed to prepare polyvinyl alcohol (PVA)/catechol-modified quaternized chitosan (QCS-C)/MXene hydrogels with good self-adhesion, frost-resistance, and high ion-conductivity. The PVA/QCS-C/MXene hydrogel shows an ionic conductivity of 8.82 S m-1 and a gauge factor of 33.53 at low strain (0-10%), and remains flexible and conductive at -47 °C. The PVA/QCS-C15/MXene hydrogel displays promising potential as an ionically conductive hydrogel sensor for applications in flexible electronic devices.

14.
ACS Appl Mater Interfaces ; 14(31): 35309-35318, 2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-35913267

RESUMO

Systemic administration of immune checkpoint blockade agents can activate the anticancer activity of immune cells; however, the response varies from patient to patient and presents potential off-target toxicities. Local administration of immune checkpoint inhibitors (ICIs) can maximize therapeutic efficacies while reducing side effects. This study demonstrates a minimally invasive strategy to locally deliver anti-programmed cell death protein 1 (anti-PD-1) with shear-thinning biomaterials (STBs). ICI can be injected into tumors when loaded in STBs (STB-ICI) composed of gelatin and silicate nanoplatelets (Laponite). The release of ICI from STB was mainly affected by the Laponite percentage in STBs and pH of the local microenvironment. Low Laponite content and acidic pH can induce ICI release. In a murine melanoma model, the injection of STB-ICI significantly reduced tumor growth and increased CD8+ T cell level in peripheral blood. STB-ICI also induced increased levels of tumor-infiltrating CD4+ helper T cells, CD8+ cytotoxic T cells, and tumor death. The STB-based minimally invasive strategy provides a simple and efficient approach to deliver ICIs locally.


Assuntos
Inibidores de Checkpoint Imunológico , Melanoma , Animais , Materiais Biocompatíveis/farmacologia , Linfócitos T CD8-Positivos , Humanos , Camundongos , Linfócitos T Citotóxicos , Microambiente Tumoral
15.
Foods ; 11(16)2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36010432

RESUMO

(1) Background: The effects of protein oxidization induced by malondialdehyde (MDA), which was selected as a representative of lipid peroxidation products, on the structure and functional properties of walnut protein were investigated. (2) Methods: Walnut protein isolate was produced by alkali-soluble acid precipitation. The modification of walnut protein isolate was conducted by MDA solutions (0, 0.01, 0.1, 1, and 10 Mm), which were incubated in the dark for 24 h. (3) Results: Increased carbonyl content and the degradation of sulfhydryl groups indicated MDA-induced protein oxidization. The circular dichroism spectra revealed disruption of the ordered protein secondary structure. The change in the tertiary conformation of the MDA-treated protein was observed through intrinsic fluorescence. Small polypeptide chain scission was observed at low MDA concentrations (≤0.1 mM) and protein aggregation was observed at high MDA concentrations (>0.1 mM) using high-performance size exclusion chromatography. Oxidized protein solubility was reduced. Furthermore, the emulsification stability index, foam capacity, and foam stability of walnut proteins were increased after treatment with 0.1 mM of MDA. An excessive concentration of MDA (>0.1 mM) decreased emulsification and foaming properties. (4) Conclusions: These results show that MDA oxidation modified the structure of walnut protein and further affected its function, which should be taken into account in processing walnut protein products.

16.
J Appl Microbiol ; 133(2): 555-568, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35437874

RESUMO

AIMS: To evaluate changes in short-chain fatty acid levels and G protein-coupled receptor 43 expression and distribution in gut microbiota and explore their relationships in obese diabetic mice after sleeve gastrectomy. METHODS AND RESULTS: Diet-induced obese mice and obese diabetic ob/ob mice were established. Changes in glucose metabolism, lipid metabolism, gut microbiota, metabolite short-chain fatty acids, and G protein-coupled receptor 43 expressions were assessed in both models 10 weeks postoperatively. Mice that underwent sleeve gastrectomy exhibited sustained weight loss and reduced glucose, insulin, leptin, and cholesterol levels. Metagenomic sequencing revealed significant characteristic alterations in gut microbiota after sleeve gastrectomy, which were correlated with changes in faecal short-chain fatty acid levels. Postoperatively, G protein-coupled receptor 43 expression in the colon tissue was upregulated in both models, whereas its expression in the adipose tissue was downregulated in the diet-induced obese mouse model. CONCLUSIONS: Metabolic improvement in obese and diabetic mice after sleeve gastrectomy is associated with alterations in gut microbiota, short-chain fatty acid levels, and G protein-coupled receptor 43 expressions. SIGNIFICANCE AND IMPACT OF STUDY: Our findings reveal a possible mechanism through which sleeve gastrectomy improves obesity and diabetes via changes in bacteria producing short-chain fatty acids and G protein-coupled receptor 43.


Assuntos
Diabetes Mellitus Experimental , Ácidos Graxos Voláteis , Microbioma Gastrointestinal , Receptores Acoplados a Proteínas G , Animais , Diabetes Mellitus Experimental/cirurgia , Ácidos Graxos Voláteis/metabolismo , Gastrectomia/métodos , Camundongos , Camundongos Obesos , Obesidade/genética , Obesidade/cirurgia , Receptores Acoplados a Proteínas G/genética
17.
J Mech Behav Biomed Mater ; 124: 104811, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34500354

RESUMO

The control of interfacial interaction between polymers and fillers is essential for the fabrication of high-performance polymer composites. In this work, poly(ether-ether-ketone)/silica (PEEK/SiO2) and PEEK/SiO2/graphene oxide (GO) composite were prepared by ball milling-ultrasonic dispersion combined with melt extrusion injection molding. GO nanosheets were introduced as the interfacial enhancer to improve interfacial binding between SiO2 and PEEK. Mechanical tests showed that the incorporation of SiO2 and GO greatly optimized the modulus, strength, and fracture toughness of the composites. The tensile strength and Young's modulus of the PEEK/SiO2 composites increases with the increase of SiO2 content. The maximum tensile strength and Young's modulus of the PEEK/SiO2 composites are approximate 95.9 ± 0.6 MPa and 4.007 ± 0.005 GPa at 30 wt% of SiO2, an increase of 6.4% and 21.2% than that of pure PEEK. The maximum tensile strength and Young's modulus of the PEEK/SiO2/GO composite are further improved to approximate 101.5 ± 0.7 MPa and 4.62 ± 0.08 GPa at a GO content of 1.5% wt, which is 12.6% and 39.4% higher than that of pure PEEK. In addition, SEM images show that numerous HA formed on the surface of the PEEK/SiO2/GO composite after immersion in SBF for 7 days, and the HA layer becomes gradually thicker after 14 days, implying the good osteogenic activity of PEEK/SiO2/GO composites. Therefore, these results suggest that the use of GO as a novel filler surface modifier for the preparation of high-performance composites may become a novel interfacial design strategy for the development of high-performance composites.


Assuntos
Cetonas , Dióxido de Silício , Éter , Éteres , Grafite , Polietilenoglicóis
18.
J Food Sci ; 86(3): 824-833, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33586780

RESUMO

A chickpea protein isolate (CPI) was oxidized using peroxyl radicals derived from 2,2'-azobis (2-amidopropane) dihydrochloride (AAPH), and the structural and foaming properties of the oxidized CPI were evaluated. The oxidation degree of protein was determined by measuring carbonyl content, dimer tyrosine content, free thiol content, and total thiol content. The structural changes of oxidized protein were evaluated by surface hydrophobicity, endogenous fluorescence intensity, Fourier transform infrared spectroscopy, SDS-PAGE, and amino acid content changes. Compared with the control group (0 mmol/L AAPH), moderate oxidation (0.04 mmol/L AAPH) led to the formation of a soluble protein with flexibility, which could improve the foaming properties of the protein (foaming capacity and stability increased by 25.50% and 6.38%, respectively). Over-oxidized (25 mmol/L AAPH) protein exhibited improved foaming capability, but its foam stability was reduced owing to the formation of insoluble aggregates. The results indicate that oxidation can change protein conformation, and the protein structure can affect the foamability of the CPI. PRACTICAL APPLICATION: CPI is a protein supplement food. Protein oxidation can occur during processing and storage, thereby affecting protein function. In this study, we evaluated how peroxy free radicals affect the structure, solubility and foaming properties of CPI, and clarified the mechanism between them. It has been found that peroxy free radicals can accelerate the oxidation of proteins and have a significant effect on foaming. Therefore, the degree of oxidation should be controlled to improve the quality of CPI.


Assuntos
Cicer/química , Peróxidos/química , Proteínas de Plantas/química , Radicais Livres/química , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Oxirredução , Proteínas de Plantas/isolamento & purificação , Conformação Proteica , Solubilidade , Compostos de Sulfidrila/análise , Tirosina/análise
19.
J Neurooncol ; 151(2): 313-324, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33394265

RESUMO

PURPOSE: Acromegaly is a rare neuroendocrine condition that can lead to significant morbidity. Despite China's vast population size, studies on acromegaly remain sparse. This study aimed to investigate the clinical characteristics and predictors of biochemical remission after surgery for acromegaly using the China Acromegaly Patient Association (CAPA) database. METHODS: A retrospective nationwide study was conducted using patient-reported data from CAPA database between 1998 and 2018. The principal component analysis (PCA) and logistic regression analysis were employed to determine independent predictors of biochemical remission at 3 months in patients after surgery. RESULTS: Of the 546 surgical cases (mean age: 36.8 years; 59.5% females), macroadenomas and invasive tumors (Knosp score 3-4) were 83.9% and 64.1%, respectively. Ninety-five percent of patients were treated with endonasal surgery and 36.8% exhibited biochemical remission at 3-months postoperatively. The following independent predictors of biochemical remission were identified: preoperative growth hormone (GH) levels between 12 and 28 µg/L [odds ratio (OR) = 0.58; 95% confidence interval (CI), 0.37-0.92; p = 0.021], preoperative GH levels > 28 µg/L (OR = 0.55; 95% CI, 0.34-0.88; p = 0.013), macroadenoma (OR = 0.56; 95% CI, 0.32-0.96; p = 0.034), giant adenomas (OR = 0.14; 95% CI, 0.05-0.38; p < 0.001), Knosp score 3-4 (OR = 0.37; 95% CI, 0.24-0.57; p < 0.001), and preoperative medication usage (OR = 2.32; 95% CI, 1.46-3.70; p < 0.001). CONCLUSIONS: In this nationwide study spanning over two decades, we highlight that higher preoperative GH levels, large tumor size, and greater extent of tumor invasiveness are associated with a lower likelihood of biochemical remission at 3-months after surgery, while preoperative medical therapy increases the chance of remission.


Assuntos
Acromegalia/cirurgia , Procedimentos Neurocirúrgicos/métodos , Acromegalia/patologia , Adulto , Feminino , Seguimentos , Humanos , Masculino , Período Pós-Operatório , Prognóstico , Indução de Remissão , Estudos Retrospectivos
20.
Small ; 17(7): e2004282, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33502118

RESUMO

Cancer immunotherapies, including immune checkpoint inhibitor (ICI)-based therapies, have revolutionized cancer treatment. However, patient response to ICIs is highly variable, necessitating the development of methods to quickly assess efficacy. In this study, an array of miniaturized bioreactors has been developed to model tumor-immune interactions. This immunotherapeutic high-throughput observation chamber (iHOC) is designed to test the effect of anti-PD-1 antibodies on cancer spheroid (MDA-MB-231, PD-L1+) and T cell (Jurkat) interactions. This system facilitates facile monitoring of T cell inhibition and reactivation using metrics such as tumor infiltration and interleukin-2 (IL-2) secretion. Status of the tumor-immune interactions can be easily captured within the iHOC by measuring IL-2 concentration using a micropillar array where sensitive, quantitative detection is allowed after antibody coating on the surface of array. The iHOC is a platform that can be used to model and monitor cancer-immune interactions in response to immunotherapy in a high-throughput manner.


Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Humanos , Imunoterapia , Dispositivos Lab-On-A-Chip , Neoplasias/tratamento farmacológico
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