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1.
Sci Rep ; 14(1): 14848, 2024 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937539

RESUMO

This study aimed to assess the safety and efficacy of interventional embolization in cirrhotic patients with refractory hepatic encephalopathy (HE) associated with large spontaneous portosystemic shunts (SPSS). Inverse probability of treatment weighting (IPTW) was employed to minimize potential bias. A total of 123 patients were included in this study (34 in the embolization group and 89 in the control group). In the unadjusted cohort, the embolization group demonstrated significantly better liver function, a larger total area of SPSS, and a higher percentage of patients with serum ammonia levels > 60 µmol/L and the presence of hepatocellular carcinoma (HCC) (all P < 0.05). In the IPTW cohort, baseline characteristics were comparable between the two groups (all P > 0.05). Patients in the embolization group exhibited significantly longer HE-free survival compared to the control group in both the unadjusted and IPTW cohorts (both P < 0.05). Subsequent subgroup analyses indicated that patients with serum ammonia level > 60 µmol/L, hepatopetal flow within the portal trunk, the presence of solitary SPSS, a baseline HE grade of II, and the absence of HCC at baseline showed statistically significant benefit from embolization treatment (all P < 0.05). No early procedural complications were observed in the embolization group. The incidence of long-term postoperative complications was comparable to that in the control group (all P > 0.05). Hence, interventional embolization appears to be a safe and effective treatment modality for cirrhotic patients with refractory HE associated with large SPSS. However, the benefits of embolization were discernible only in a specific subset of patients.


Assuntos
Embolização Terapêutica , Encefalopatia Hepática , Cirrose Hepática , Humanos , Encefalopatia Hepática/terapia , Encefalopatia Hepática/etiologia , Masculino , Feminino , Embolização Terapêutica/métodos , Pessoa de Meia-Idade , Cirrose Hepática/complicações , Cirrose Hepática/terapia , Idoso , Resultado do Tratamento , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/complicações , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/complicações , Estudos Retrospectivos , Amônia/sangue
2.
Food Chem ; 452: 139564, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38718455

RESUMO

High internal phase Pickering emulsions (HIPPEs) prepared from natural polymers have attracted much attention in the food manufactures. However, single zein-stabilized HIPPEs are poorly stable and prone to flocculation near the isoelectric point. To address this issue, in this study, zein and whey protein nanofibrils (WPN) complex nanoparticles (ZWNPs) were successfully prepared using a pH-driven method, and ZWNPs were further used as HIPPEs stabilizers. The results showed that zein and WPN were combined together through hydrogen bonding and hydrophobic interaction to form ZWNPs, and the HIPPEs stabilized by ZWNPs had excellent stability, which could effectively protect the internally encapsulated lycopene and improve the bioaccessibility of lycopene. In conclusion, this study provides a new strategy for the preparation of stable hydrophobic protein-based HIPPEs, represented by zein.


Assuntos
Emulsões , Interações Hidrofóbicas e Hidrofílicas , Licopeno , Proteínas do Soro do Leite , Zeína , Zeína/química , Emulsões/química , Licopeno/química , Proteínas do Soro do Leite/química , Nanofibras/química , Nanopartículas/química
3.
BMJ Open ; 14(2): e081194, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38346880

RESUMO

INTRODUCTION: The presence of spontaneous portosystemic shunts (SPSS) has been identified to be associated with hepatic encephalopathy (HE) in patients with cirrhosis. Nevertheless, the role of interventional embolisation in managing such patients remains poorly defined. Consequently, this prospective controlled study aims to assess the efficacy and safety of interventional embolisation as a therapeutic approach for patients with cirrhosis and recurrent or persistent HE related to SPSS. METHODS AND ANALYSIS: Cirrhotic patients diagnosed with recurrent or persistent HE associated with SPSS will be recruited for this study, and assigned to either the interventional embolisation group or the standard medical treatment group. The efficacy endpoints encompass the evaluation of postoperative alleviation of HE symptoms and the incidence of overt HE recurrence during the follow-up period, as well as the duration and frequency of hospitalisations for HE, alterations in liver function and volume, and overall survival. The safety endpoints encompass both immediate and long-term postoperative complications. ETHICS AND DISSEMINATION: This study will be conducted in strict adherence to the principles of good clinical practice and the guidelines outlined in the Declaration of Helsinki. Ethical approval for the trial has been obtained from the Ethics Committee of Mengchao Hepatobiliary Hospital of Fujian Medical University (2023_013_02). Written informed consent will be obtained from all the participants by the treating physician for each patient prior to their enrolment. The documented informed consent forms will be retained as part of the clinical trial records for future reference. The study findings will be disseminated through publication in peer-reviewed journals and will be presented at international conferences. TRIAL REGISTRATION NUMBER: ChiCTR2300072189.


Assuntos
Encefalopatia Hepática , Derivação Portossistêmica Transjugular Intra-Hepática , Humanos , Encefalopatia Hepática/terapia , Encefalopatia Hepática/complicações , Cirrose Hepática/complicações , Cirrose Hepática/terapia , Derivação Portossistêmica Transjugular Intra-Hepática/efeitos adversos , Estudos Prospectivos , Projetos de Pesquisa , Resultado do Tratamento , Ensaios Clínicos Controlados não Aleatórios como Assunto
4.
Int J Biol Macromol ; 259(Pt 1): 129257, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38191111

RESUMO

This study evaluated the influence of chestnut powder, produced using ball mill superfine grinding (BMSG), jet superfine grinding (JSG), and ordinary grinding (OG), on wheat flour properties. Blending wheat flour with chestnut powder resulted in a darker flour blend (3 % decline of L*), with decreased the tap density and increased water holding capacity. Adding appropriate proportion of superfine chestnut powder can bolster the mixed flour's thermal stability (15 % BMSG/JSG) and freeze-thaw stability (10 % BMSG/JSG), while significantly enhancing the anti-aging properties of flour products. The proposition of 5 % superfine BMSG/JSG did not significantly affect the tensile resistance of the dough, and even improve the dough's tensile strength. In addition, the hardness, adhesiveness, springiness and pH of fermentation increased due to the addition of chestnut powder, as supported by the dough texture analyses and fermentation characteristics findings. However, the excessive addition of chestnut powder affected the dough network's structural integrity to some extent. Further study can focus on the influencing mechanism of chestnut powder on gluten formation and related nutritional properties. Overall, this research underscores the potential of utilizing chestnut powder to enhance the nutritional and functional qualities of wheat-based products.


Assuntos
Farinha , Triticum , Triticum/química , Pós/química , Farinha/análise , Glutens/química , Dureza
5.
Int J Biol Macromol ; 256(Pt 1): 128307, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992941

RESUMO

Films with simultaneously excellent mechanical and anti-fog properties are of great importance for food packaging. A novel strategy is described here to prepare long-lasting anti-fog film with antibacterial and antioxidant capabilities via a simple, green approach. The CMC (carboxymethyl chitosan) gel was integrated with CNF/TA (cellulose nanofibers/tannic acid) composite solution based on layer-by-layer assembly to form a membrane with a bilayer structure. The anti-fog performance of the bilayer film could be adjusted by regulating the CNF/TA layer thickness. On the whole, the developed anti-fog film had high mechanical strength and excellent UV shielding properties, as well as good antibacterial and antioxidant properties, and could be non-fogging for a long time under water vapor (40 °C). The effect of double layer anti-fog film (3%CmFT-3) on the fresh-keeping effect of white Hypsizygus marmoreus was compared at room temperature (28 °C) with commercially available anti-fog PVC film. The results showed that the bilayer anti-fog film could effectively prevent the generation of fog, delay the Browning, inhibit mildew, improve the overall acceptability, and effectively extend the shelf life of white Hypsizygus marmoreus. This biomass-based anti-fog film offers great potential for the development of multifunctional green food packaging.


Assuntos
Agaricales , Quitosana , Nanofibras , Polifenóis , Quitosana/farmacologia , Quitosana/química , Celulose/farmacologia , Celulose/química , Nanofibras/química , Antioxidantes/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Embalagem de Alimentos
6.
Small ; 19(42): e2303368, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37328446

RESUMO

Unpredictable and extreme weather conditions, along with increasing electromagnetic pollution, have resulted in a significant threat to human health and productivity, causing irreversible damage to society's well-being and economy. However, existing personal temperature management and electromagnetic protection materials lack adaptability to dynamic environmental changes. To address this, a unique asymmetric bilayer leather/a-MWCNTs/CA fabric is developed by vacuum-infiltrating interconnected a-MWCNTs networks into natural leather's microfiber backbone and spraying porous acetic acid (CA) on the reverse side. Such fabric achieves simultaneous passive radiation cooling, heating, and anti-electromagnetic interference functions without external energy input. The fabric's cooling layer has high solar reflectance (92.0%) and high infrared emissivity (90.2%), providing an average subambient radiation cooling effect of 10 °C, while the heating layer has high solar absorption (98.0%), enabling excellent passive radiative heating and effective compensation for warming via Joule heating. Additionally, the fabric's 3D conductive a-MWCNTs network provides electromagnetic interference shielding effectiveness of 35.0 dB mainly through electromagnetic wave absorption. This multimode electromagnetic shielding fabric can switch between cooling and heating modes to adapt to dynamic cooling and heating scenarios, providing a new avenue for sustainable temperature management and electromagnetic protection applications.

7.
Adv Sci (Weinh) ; 10(11): e2206925, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36793107

RESUMO

High indoor humidity/temperature pose serious public health threat and hinder industrial productivity, thus adversely impairing the wellness and economy of the entire society. Traditional air conditioning systems for dehumidification and cooling involve significant energy consumption and have accelerated the greenhouse effect. Here, this work demonstrates an asymmetric bilayer cellulose-based fabric that enables solar-driven continuous indoor dehumidification, transpiration-driven power generation, and passive radiative cooling using the same textile without any energy input. The multimode fabric (ABMTF) consists of a cellulose moisture absorption-evaporation layer (ADF) and a cellulose acetate (CA) radiation layer. The ABMTF exhibits a high moisture absorption capacity and water evaporation rate, which quickly reduces the indoor relative humidity (RH) to a comfortable level (40-60% RH) under 1 sun illumination. The evaporation-driven continuous capillary flow generates a maximum open-circuit voltage (Voc ) of 0.82 V, and a power density (P) up to 1.13 µW cm-3 . When a CA layer with high solar reflection and mid-infrared (mid-IR) emissivity faces outward, it realizes subambient cooling of ≈12 °C with average cooling power of ≈106 W m-2 at midday under radiation of 900 W m-2 . This work brings a new perspective to develop the next-generation, high performance environmentally friendly materials for sustainable moisture/thermal management and self-powered applications.

8.
Int J Biol Macromol ; 231: 123362, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36690235

RESUMO

The utilization of microcarriers is an effective technique to protect and slow down the release of active ingredients, while the combination of microcarriers and film materials is an important way to expand the application scenario of active ingredients. The aim of this study was to develop a simple and facile strategy for designing a multifunctional bilayer bioactive film that combines stable mechanical properties, sustained-release characteristics for active ingredients with good antioxidant and antibacterial properties. The EGCG-loaded chitosan active microspheres were prepared by sol-gel method, and then the carboxymethyl cellulose solution containing the active microspheres was assembled onto the carboxymethyl chitosan gel substrate based on intermolecular hydrogen bonding to construct a film with a stable bilayer structure. The results indicated that the bilayer film had dense microstructure and excellent mechanical strength (37.05 MPa), and exhibited UV-blocking properties and excellent gas barrier performance. Meanwhile, the loading of active ingredients (EGCG) in the microspheres enabled the bilayer film to exhibit excellent antioxidant and antibacterial properties, and the controlled release of EGCG by the film was sustainable and showed pH responsiveness. The results of this work provide a new perspective for the design and development of bio-based active packaging film with tunable functional characteristics.


Assuntos
Quitosana , Quitosana/química , Antioxidantes/química , Microesferas , Antibacterianos/química , Embalagem de Alimentos
9.
J Food Sci ; 87(8): 3459-3471, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35838074

RESUMO

The Maillard reaction (MR) has been known to modify proteins and optimize their physicochemical properties by conjugating with reducing sugars. The structure and physicochemical properties of wheat gliadin and maize amylopectin conjugates induced by MR were investigated under different gliadin-amylopectin ratios (2:1, 1:1, 1:2, 1:4, and 1:8). The formation of conjugates was indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, degree of conjugation, and browning development analyses. The Fourier transform infrared and fluorescence spectroscopy analyses suggested changes in the structures of conjugates and the microenvironment of amino acids. A remarkable decrease in the ß-turn structure content and an increase in the free sulfhydryl group content were observed at a ratio of 1:8, leading to decreased allergenicity. The reaction process was commendably controlled at a ratio of 1:1 with a 59.7% degree of conjugation in this group, contributing to the amelioration of solubility and foaming properties. Meanwhile, improvements in the oil holding capacity, surface hydrophobicity, and emulsifying properties were observed at a ratio of 1:4. PRACTICAL APPLICATION: The study revealed that the conjugates produced by MR might have various degrees of improved functional properties and reduced allergenicity at different ratios of substrates. Our study might be helpful for conjugates to assist in improving the texture of products and its potential in expanding the industrial application of products with gliadin.


Assuntos
Amilopectina , Zea mays , Emulsões/química , Gliadina , Calefação , Triticum
10.
Int J Biol Macromol ; 215: 12-22, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35718142

RESUMO

Excessive exposure to ultraviolet B (UVB) irradiation is one of the major risk factors for skin photoaging. The aim of this study was to investigate the protective effect of Premna microphylla Turcz pectin (PMTP) against UVB-induced skin aging in BALB/c-nu mice. PMTP was characteristic of a low methoxyl RG-I pectin with Mw was 26.60 kDa, mainly composed of galacturonic acid. PMTP-containing cream efficiently inhibited the water loss, epidermal hyperplasia, matrix metalloproteinases-1 (MMP-1), and collagen destruction in UVB-induced skin injury mice. Additionally, topical administration of PMTP-containing cream significantly increased protein levels of the nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), macrophage-activating factor (Maf), and heme oxygenase 1 (HO-1), and the expression of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). In contrast, application of PMTP-containing cream on mice skin decreased the protein levels of nuclear factor-kappa B (NF-κB), inhibitor kappa B kinase ß (IKKß), and cyclooxygenase-2 (COX-2), and pro-inflammatory cytokines. Taken togethmier, these findings suggest that PMTP might protect UVB-induced skin aging via activating Nrf2 pathway and suppressing NF-κB pathway.


Assuntos
Lamiaceae , Fator 2 Relacionado a NF-E2 , Pectinas , Envelhecimento da Pele , Animais , Camundongos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Lamiaceae/química , Camundongos Endogâmicos BALB C , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Pectinas/farmacologia , Pele , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/genética , Envelhecimento da Pele/fisiologia , Raios Ultravioleta/efeitos adversos , Preparações de Plantas/farmacologia
11.
Food Chem ; 378: 132091, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35032808

RESUMO

The biological activity and absorption of curcumin (Cur) is limited in application due to its low water solubility, poorstabilityand rapid metabolism. In this work, Cur loaded (-)-epigallocatechin-3-gallate (EGCG)/poly(N-vinylpyrrolidone) (PVP) nanoparticles (CEP-NPs) was successfully fabricated via self-assembly driven by hydrogen bonding, providing with desirable Cur-loading efficiency, high stability, strong antioxidant capacity, and pH-triggered intestinal targeted release properties. Molecular dynamics simulations further indicated the Cur was coated with EGCG and PVP in CEP-NPs and high acid prolonged release property was attribute to low ionization degree of EGCG. Besides, the enhanced intestinal absorption of Cur was related to inhibition of Cur metabolism by EGCG, enhancement of cellular uptake and higher Caco-2 monolayer permeation. Pharmacokinetic study showed that the oral bioavailability presented nearly 12-fold increment. Therefore, this study provides a new horizon for improving the Cur utilization in food and pharmaceutical fields.


Assuntos
Curcumina , Nanopartículas , Disponibilidade Biológica , Células CACO-2 , Catequina/análogos & derivados , Portadores de Fármacos , Humanos , Ligação de Hidrogênio , Tamanho da Partícula , Pirrolidinonas
12.
Food Chem ; 373(Pt B): 131489, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-34749091

RESUMO

Zein is potential in encapsulating and delivering polyphenols in food industry. Our study investigated the interaction mechanisms and structural changes of the interaction between ferulic acid (FA) and zein under different CaCl2 concentrations. Addition of CaCl2 resulted in amino acids micro-environment and structural changes of zein and zein/FA complex, which was dependent on different CaCl2 concentrations. At 0.5 mol/L CaCl2 concentration, zein/FA exhibited spherical particles with rough surfaces. Fourier transform infrared analysis showed the decrease of α-helix and ß-sheets contents accompanied by the increase of ß-turns and unordered coil contents. Molecular dynamics simulation demonstrated FA interacted with zein mainly through hydrogen bonds and hydrophobic force. These observations might contribute to the decreased surface hydrophobicity and digestibility of zein. Results provided a better understanding of the interaction between zein and other molecules, which might be helpful for the development of zein particles as functional materials to encapsulate and deliver bioactive compounds.


Assuntos
Zeína , Cloreto de Cálcio , Ácidos Cumáricos , Interações Hidrofóbicas e Hidrofílicas
13.
J Food Sci ; 87(1): 80-93, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34935129

RESUMO

Proteins, one of the vital nutritional compounds sensitive to the environment, can be modified by interaction with polyphenols. Ultrasonication has been applied for enhancing the functional properties of proteins. In this study, the interactions of gliadin (G) and rutin (R) in the absence and presence of ultrasonication (0, 150, 300, 450, and 600 W) for 20 min were investigated, with a focus on the properties of emulsions prepared by G-R complexes. Ultrasonication improved the interaction, which increased the content of ß-type secondary structure. Ultrasonication at 450 W increased the particle size of the conjugates. For Pickering emulsions, treating the covering of R on G with ultrasonication improves the stability of the G-based emulsion significantly, owing to the strong films formed on the oil-water interfaces. The G-R complexes treated at 450 W ultrasonication formed emulsions that showed higher potential and storage modulus (G') and denser microstructures than those of the untreated emulsions. Nevertheless, ultrasound treatment at 600 W weakened the emulsion properties that were stabilized by the conjugates. Ultrasound combined R was shown to be a potential processing technology for changing the protein structure and producing stable emulsions. PRACTICAL APPLICATION: The interactions between proteins and polyphenols are able to preserve the stability of the functional compounds, allow targeted and controlled release, and improve the texture of these complexes employed in the food industry. Improvements in the functional characteristics of the protein-polyphenol complexes so that they possess high emulsifying stability during food processing is a crucial factor for employing them in the food industry. Therefore, the aim of this research is using a soluble complex of gliadin-rutin for the development of its functional characteristics.


Assuntos
Gliadina , Nanopartículas , Emulsões , Tamanho da Partícula , Rutina , Água
14.
Food Funct ; 12(24): 12647-12658, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34821891

RESUMO

Anthocyanins have anti-inflammatory, anticarcinogenic and antioxidant properties and anti-aging effects as well as potential application as pigments. The metabolism of anthocyanins in fermented food has attracted increasing attention. However, the effect of lactic acid bacteria (LAB) fermentation on its anti-aging activity remains mostly unknown. The current study aimed to investigate the compositions, antioxidant activities and anti-aging effect of fermented purple sweet potato anthocyanins (FSPA) on aging Caenorhabditis elegans compared to raw purple sweet potato anthocyanins (PSPA). Results showed that anthocyanins were degraded into more bioavailable phenolic acids by Weissella confusa fermentation. PSPA and FSPA can extend the lifespan of C. elegans by 26.7% and 37.5%, respectively, through improving the activity of antioxidant enzymes as well as decreasing MDA content, ROS levels and lipofuscin accumulation. Pretreatment of the worms with PSPA and FSPA induced their potential to resist to thermal tolerance and oxidative stress, and FSPA exerted a higher anti-stress effect than PSPA. Moreover, FSPA supplementation upregulated the mRNA expressions of genes daf-16, hsp-16.2, sir-2.1, skn-1 and sod-3 and downregulated the expression of daf-2 in the nematodes, whereas PSPA only induced the increase in the expressions of sir-2.1, skn-1 and sod-3. Overall, FSPA can improve stress resistance and extend the lifespan of C. elegans by both insulin/IGF-1 signaling pathway and dietary restriction pathway, providing a theoretical basis for the application of PSPA in fermented food as functional pigments.


Assuntos
Envelhecimento/efeitos dos fármacos , Antocianinas/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Ipomoea batatas/metabolismo , Extratos Vegetais/farmacologia , Animais , Fermentação
15.
Int J Pharm ; 602: 120650, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33957265

RESUMO

Curcumin (Cur), a hydrophobic active pharmaceutical ingredient with high anticancer activity, has poor water solubility and low bioavailability. Although many delivery systems have been developed to improve their bioavailability, some limitation such as low drug loading efficiency and poor stability are still remained. The metal-polyphenol networks (MPNs) delivery system designed in this subject solved above problems and effectively improved the anticancer activity of Cur. The synthesized Cur@EGCG-Fe(III) is consisting of epigallocatechin gallate (EGCG), iron chloride (FeCl3) and Cur, and the well-designed structure endow Cur@EGCG-Fe(III) high loading efficiency, good water solubility and stability. After the Cur@EGCG-Fe(III) nanoparticles were internalized by MCF-7 cells, the Cur could be released in endo/lysosomal microenvironment (pH = 5.0), and the Cur delivery in the deep tumor could be realized. The distribution of Cur@EGCG-Fe(III) in MCF-7 cells was analyzed by laser confocal, and Cur@EGCG-Fe(III) could effectively deliver more Cur into MCF-7 cells in comparison with free Cur. In addition, the results of flow cytometry and western blot further indicated that Cur@EGCG-Fe(III) had a stronger ability to induce apoptosis than free Cur. Transwell cell migration and invasion experiments showed that Cur and EGCG-Fe(III) had a synergistic effect in inhibiting MCF-7 cell migration and invasion. In vitro hemolysis and in vivo experiments showed that the Cur@EGCG-Fe(III) had negligible effect on the blood environment and a great tumor-inhibition efficacy, indicating that the MPNs delivery system had a good blood compatibility and antitumor activity. Our results indicated that MPNs-coated Cur nanoparticle could be a new form of Cur delivery system for anticancer application.


Assuntos
Antineoplásicos , Curcumina , Nanopartículas , Sistemas de Liberação de Medicamentos , Compostos Férricos , Humanos , Células MCF-7 , Polifenóis , Solubilidade
16.
Chem Commun (Camb) ; 57(15): 1895-1898, 2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33491703

RESUMO

Herein, we report a general strategy based on host-guest interactions to fabricate atomically dispersed biomimetic catalysts, which were evaluated by diboration of phenylacetylene. The structure and function of these mimics are quite similar to those of enzymes, namely, the atomically dispersed metal serves as an active site, the external macromolecular structure plays a role as an enzyme catalytic pocket to stabilize the reaction intermediates and the interactions between the intermediates and functional groups near to the active site can reduce the reaction activation energy.


Assuntos
Materiais Biomiméticos/química , Catálise , Domínio Catalítico , Metais/química , Modelos Moleculares , Estrutura Molecular , Polímeros/química , beta-Ciclodextrinas/química
17.
Foods ; 11(1)2021 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-35010176

RESUMO

Ulcerative colitis (UC) is a chronic and nonspecific inflammatory disease of the colon and rectum, and its etiology remains obscure. Cherry polyphenols showed potential health-promoting effects. However, both the protective effect and mechanism of cherry polyphenols on UC are still unclear. This study aimed to investigate the potential role of the free polyphenol extract of cherry in alleviating UC and its possible mechanism of action. Our study revealed that the free polyphenol extract of cherry management significantly alleviated UC symptoms, such as weight loss, colon shortening, the thickening of colonic mucous layer, etc. The free polyphenol extract of cherry treatment also introduced a significant reduction in levels of malondialdehyde (MDA), myeloperoxidase (MPO) and nitric oxide (NO), while causing a significant elevation in levels of catalase (CAT), glutathione (GSH-Px), superoxide dismutase (SOD), as well as the downregulation of pro-inflammatory cytokines. This indicated that such positive effects were performed through reducing oxidative damage or in a cytokine-specific manner. The immunofluorescence analysis of ZO-1 and occludin proteins declared that the free polyphenol extract of cherry had the potential to prompt intestinal barrier function. The reduced expression levels of ß-catenin, c-myc, cyclin D1 and GSK-3ß suggested that the cherry extract performed its positive effect on UC by suppressing the Wnt/ß-ctenin pathway. This finding may pave the way into further understanding the mechanism of cherry polyphenols ameliorating ulcerative colitis.

18.
Int J Biol Macromol ; 142: 404-411, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31626821

RESUMO

In this work, the coagulation mechanism of the cellulose/metal nanohybrids and the binding mode with Cr (VI) are deeply described. Nanohybrids with 3D porous networks were prepared from cellulose/Fe2O3-SO3H solutions through a simple one-step coagulation process in NaCl aqueous solutions. The structure and properties of nanohybrids were characterized by SEM, EDS, XRD, FTIR, and XPS. The cellulose/metal nanohybrids have a langmuir maximum adsorption capacity of 11.46 mg/g. The dissolved metal nanoparticles could form strong hydrogen bonding with cellulose by breaking the intermolecular hydrogen bonds between the polymer molecules. The porous networks of cellulose/metal nanohybrids provided multiple adsorption sites for Cr2O72- anion through FeO…Cr interactions. The cooperation between cellulose and Fe2O3-SO3H nanoparticles makes the hybrids exhibiting a satisfactory selectivity and affinity for Cr (VI). The cellulose/metal nanohybrids selectively interacted with Cr2O72- via Fe atom from Fe2O3 and oxygen atom from SO3- groups. The Cr (VI) adsorption occurred via a two-step process, the first of them was the initial adsorption of Cr2O72- on cellulose/metal nanohybrids surface, followed by the rearrangement of Cr2O72- molecules and the consecutive growth of Cr2O72- aggregate layers.


Assuntos
Celulose/química , Cromo/química , Nanopartículas Metálicas/química , Metais/química , Adsorção , Coagulação Sanguínea , Compostos de Cromo/química , Concentração de Íons de Hidrogênio , Cinética , Nanopartículas Metálicas/ultraestrutura , Concentração Osmolar , Análise Espectral/métodos
19.
Adv Mater ; 31(46): e1904762, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31566289

RESUMO

Wrinkled hydrogels from biomass sources are potential structural biomaterials. However, for biorelated applications, engineering scalable, structure-customized, robust, and biocompatible wrinkled hydrogels with highly oriented nanostructures and controllable intervals is still a challenge. A scalable biomass material, namely cellulose, is reported for customizing anisotropic, all-cellulose, wrinkle-patterned hydrogels (AWHs) through an ultrafast, auxiliary force, acid-induced gradient dual-crosslinking strategy. Direct immersion of a prestretched cellulose alkaline gel in acid and relaxation within seconds allow quick buildup of a consecutive through-thickness modulus gradient with acid-penetration-directed dual-crosslinking, confirmed by visual 3D Raman microscopy imaging, which drives the formation of self-wrinkling structures. Moreover, guided by quantitative mechanics simulations, the structure of AWHs is found to exhibit programmable intervals and aligned nanostructures that differ between ridge and valley regions and can be controlled by tuning the prestretching strain and acid treatment time, and these AWHs successfully induce cell alignment. Thus, a new avenue is opened to fabricate polysaccharide-derived, programmable, anisotropic, wrinkled hydrogels for use as biomedical materials via a bottom-up method.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Celulose/química , Química Verde , Hidrogéis/química , Hidrogéis/farmacologia , Fenômenos Mecânicos , Células 3T3 , Animais , Anisotropia , Adesão Celular/efeitos dos fármacos , Camundongos
20.
Angew Chem Int Ed Engl ; 58(49): 17834-17842, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31549478

RESUMO

Metal halide perovskites have emerged as a new generation of X-ray detector materials. However, large-sized MAPbI3 single crystals (SCs) still exhibit lower performance than MAPbBr3 SCs in X-ray detection. DFT (density functional theory) simulations suggest the problem could be overcome by alloying large-sized cations at the A site. The alloyed process could notably decrease the electron-phonon coupling strength and increase the material defect formation energy. Accordingly, centimeter-sized alloyed DMAMAPbI3 (DMA=dimethylammonium) and GAMAPbI3 (GA=guanidinium) SCs are obtained. Electrical characterizations confirm the GAMAPbI3 SCs display improved charge collection efficiency. It also exhibits a remarkable reduction of dark current, an important figure of merit for X-ray detectors. With a judiciously designed device architecture, the overall detector performance confirms GAMAPbI3 SCs as one of the most sensitive perovskite X-ray detectors to date.

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