RESUMO
PURPOSE: Breast cancer survivors face dual challenges: long-term sequelae of treatment and the risk of recurrent disease. Furthermore, obesity and a sedentary lifestyle can complicate both challenges. We aimed to assess the effect of a 12-week exercise-based weight-management program in overweight/obese breast cancer survivors. METHODS: A two-arm, single-blinded, randomized controlled trial was conducted among 60 overweight/obese, stage 0-III breast cancer survivors. During the 12-week program, the intervention group received weekly information support, fortnightly exercise prescriptions, including aerobic and resistance exercises to perform at home, and one dietary instruction. The control group received information support about weight management and exercise. Weight, body composition, and physical fitness data were collected at baseline, postintervention, and the 3-month follow-up. RESULTS: The intervention group showed significant improvements in body weight and all adiposity indices, including body mass index, waist circumference, and %body fat, in comparison with baseline (P < 0.001) and the control group (P < 0.05). Both groups showed no significant changes in fat-free mass during the 6-month period (P > 0.05). International Physical Activity Questionnaire scores and left grip strength increased significantly in the intervention group in comparison with the baseline (P < 0.01) and the control group (P < 0.05). Right grip strength, lower-body strength, and aerobic endurance showed no significant intergroup differences (P > 0.05). CONCLUSIONS: A combination of exercise prescription and weight-loss interventions yielded clinically meaningful weight loss in overweight/obese breast cancer survivors. These findings may facilitate the incorporation of home-based exercise and weight management into breast cancer treatment and survivorship care.
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Carcinoma de Mama in situ , Neoplasias da Mama , Sobreviventes de Câncer , Humanos , Feminino , Neoplasias da Mama/complicações , Neoplasias da Mama/terapia , Sobrepeso/terapia , Mama , Obesidade/terapiaRESUMO
Here, we report that important regulators of cilia formation and ciliary compartment-directed protein transport function in secretion polarity. Mutations in cilia genes cep290 and bbs2, involved in human ciliopathies, affect apical secretion of Cochlin, a major otolith component and a determinant of calcium carbonate crystallization form. We show that Cochlin, defective in human auditory and vestibular disorder, DFNA9, is secreted from small specialized regions of vestibular system epithelia. Cells of these regions secrete Cochlin both apically into the ear lumen and basally into the basal lamina. Basally secreted Cochlin diffuses along the basal surface of vestibular epithelia, while apically secreted Cochlin is incorporated into the otolith. Mutations in a subset of ciliopathy genes lead to defects in Cochlin apical secretion, causing abnormal otolith crystallization and behavioral defects. This study reveals a class of ciliary proteins that are important for the polarity of secretion and delineate a secretory pathway that regulates biomineralization.
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Ciliopatias/genética , Membrana dos Otólitos/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Síndrome de Bardet-Biedl/genética , Sequência de Bases , Cílios/metabolismo , Cristalização , Epistasia Genética , Proteínas da Matriz Extracelular/genética , Regulação da Expressão Gênica no Desenvolvimento , Homozigoto , Mutação/genética , Fenótipo , Proteínas de Peixe-Zebra/genéticaRESUMO
In vertebrate photoreceptors, opsins are highly concentrated in a morphologically distinct ciliary compartment known as the outer segment (OS). Opsin is synthesized in the cell body and transported to the OS at a remarkable rate of 100 to 1000 molecules per second. Opsin transport defects contribute to photoreceptor loss and blindness in human ciliopathies. Previous studies revealed that the rhodopsin C-terminal tail, of 44 amino acids, is sufficient to mediate OS targeting in Xenopus photoreceptors. Here, we show that, although the Xenopus C-terminus retains this function in zebrafish, the homologous zebrafish sequence is not sufficient to target opsin to the OS. This functional difference is largely caused by a change of a single amino acid present in Xenopus but not in other vertebrates examined. Furthermore, we find that sequences in the third intracellular cytoplasmic loop (IC3) and adjacent regions of transmembrane helices 6 and 7 are also necessary for opsin transport in zebrafish. Combined with the cytoplasmic tail, these sequences are sufficient to target opsin to the ciliary compartment.
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Rodopsina , Peixe-Zebra , Animais , Humanos , Células Fotorreceptoras/metabolismo , Células Fotorreceptoras de Vertebrados/metabolismo , Transporte Proteico , Rodopsina/genética , Rodopsina/metabolismo , Segmento Externo da Célula Bastonete/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismoRESUMO
OBJECTIVES: To investigate superiority of a telerehabilitation programme for COVID-19 (TERECO) over no rehabilitation with regard to exercise capacity, lower limb muscle strength (LMS), pulmonary function, health-related quality of life (HRQOL) and dyspnoea. DESIGN: Parallel-group randomised controlled trial with 1:1 block randomisation. SETTING: Three major hospitals from Jiangsu and Hubei provinces, China. PARTICIPANTS: 120 formerly hospitalised COVID-19 survivors with remaining dyspnoea complaints were randomised with 61 allocated to control and 59 to TERECO. INTERVENTION: Unsupervised home-based 6-week exercise programme comprising breathing control and thoracic expansion, aerobic exercise and LMS exercise, delivered via smartphone, and remotely monitored with heart rate telemetry. OUTCOMES: Primary outcome was 6 min walking distance (6MWD) in metres. Secondary outcomes were squat time in seconds; pulmonary function assessed by spirometry; HRQOL measured with Short Form Health Survey-12 (SF-12) and mMRC-dyspnoea. Outcomes were assessed at 6 weeks (post-treatment) and 28 weeks (follow-up). RESULTS: Adjusted between-group difference in change in 6MWD was 65.45 m (95% CI 43.8 to 87.1; p<0.001) at post-treatment and 68.62 m (95% CI 46.39 to 90.85; p<0.001) at follow-up. Treatment effects for LMS were 20.12 s (95% CI 12.34 to 27.9; p<0.001) post-treatment and 22.23 s (95% CI 14.24 to 30.21; p<0.001) at follow-up. No group differences were found for lung function except post-treatment maximum voluntary ventilation. Increase in SF-12 physical component was greater in the TERECO group with treatment effects estimated as 3.79 (95% CI 1.24 to 6.35; p=0.004) at post-treatment and 2.69 (95% CI 0.06 to 5.32; p=0.045) at follow-up. CONCLUSIONS: This trial demonstrated superiority of TERECO over no rehabilitation for 6MWD, LMS, and physical HRQOL. TRIAL REGISTRATION NUMBER: ChiCTR2000031834.
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COVID-19 , Telerreabilitação , Assistência ao Convalescente , Dispneia/reabilitação , Humanos , Alta do Paciente , Qualidade de VidaRESUMO
BACKGROUND: This study aimed to explore the biological activities of miR-330-3p in dextan sulphate sodium (DSS)-induced ulcerative colitis and apoptosis and the direct target of miR-330-3p in this process. HT-29 cells and male C57BL/6 mice were used to examine the function of miR-330-3p in vitro and in vivo, respectively. Expression of miRNA and mRNA was measured using quantitative real time PCR (qRT-PCR). Western blotting was used to measure the change of protein expression. Flow cytometry was used to determine cell apoptosis and luciferase assay was used to confirm the direct target of miR-330-3p. RESULTS: miR-330-3p expression was increased by DSS in both HT-29 cells and mice. Upregulation miR-330-3p induced cell apoptosis, mice weight loss and ulcerative colitis in vivo, which could prevent by suppression of miR-330-3p. Cell apoptosis related protein expression, cleaved caspase-3 and cleaved PARP was also inhibited by miR-330-3p overexpression and elevated by miR-330-3p inhibition both in vitro and in vivo. Luciferase assay confirmed that 3' untranslated region (3'-UTR) of XBP1 is the directed target of miR-330-3p and Western blotting results have showed that protein expression of XBP1 was decreased by miR-330-3p mimics and increased by miR-330-3p inhibitor. CONCLUSION: miR-330-3p is upregulated by DSS in both HT-29 cells and mice and promoted ulcerative colitis and cell apoptosis by targeting of 3'-UTR of XBP1, which is a key component of ER stress. Inhibition of miR-330-3p prevent DSS-induced ulcerative colitis and cell apoptosis mediated by upregulation of XBP1 expression.
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Apoptose , Colite Ulcerativa/genética , Estresse do Retículo Endoplasmático , MicroRNAs/genética , Proteína 1 de Ligação a X-Box/genética , Regiões 3' não Traduzidas , Animais , Colite Ulcerativa/induzido quimicamente , Sulfato de Dextrana , Técnicas de Silenciamento de Genes , Células HT29 , Humanos , Masculino , Camundongos Endogâmicos C57BL , Regulação para CimaRESUMO
Developing phase change materials (PCMs) with suitable phase change temperatures and high latent heat is of great significance for accelerating the development of latent heat storage technology to be applied in solar water heating (SWH) systems. The phase change performances of two mixtures, NH4Al(SO4)2·12H2O-MgCl2·6H2O (mixture-A) and KAl(SO4)2·12H2O-MgCl2·6H2O (mixture-B), were investigated in this paper. Based on the DSC results, the optimum contents of MgCl2·6H2O in mixture-A and mixture-B were determined to be 30 wt%. It is found that the melting points of mixture-A (30 wt% MgCl2·6H2O) and mixture-B (30 wt% MgCl2·6H2O) are 64.15 °C and 60.15 °C, respectively, which are suitable for SWH systems. Moreover, two mixtures have high latent heat of up to 192.1 kJ/kg and 198.1 kJ/kg as well as exhibit little supercooling. After 200 cycles heating-cooling experiments, the deviations in melting point and melting enthalpy of mixture-A are only 1.51% and 1.20%, respectively. Furthermore, the XRD patterns before and after the cycling experiments show that mixture-A possesses good structure stability. These excellent thermal characteristics make mixture-A show great potential for SWH systems.
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Compostos de Alúmen/química , Compostos de Alumínio/química , Cloreto de Magnésio/química , Compostos de Potássio/química , Sulfatos/química , Varredura Diferencial de Calorimetria , Estrutura Molecular , Transição de Fase , Termogravimetria , Difração de Raios XRESUMO
Herein a novel multi-controlled drug release system for doxorubicin (DOX) was developed, in which monodisperse mesoporous Fe3O4 nanoparticles were combined with a phase change material (PCM) and polyethylene glycol 2000 (PEG2000). It is found that the PCM/PEG/DOX mixture containing 20% PEG could be dissolved into water at 42 °C. The mesoporous Fe3O4 nanoparticles prepared by the solvothermal method had sizes of around 25 nm and exhibited a mesoporous microstructure. A simple solvent evaporation process was employed to load the PCM/PEG/DOX mixture on the mesoporous Fe3O4 nanoparticles completely. In the Fe3O4@PCM/PEG/DOX system, the pores of the Fe3O4 nanoparticles were observed to be filled with the mixture of PCM/PEG/DOX. The Fe3O4@PCM/PEG/DOX system showed a saturation magnetization value of 50.0 emu g-1, lower than 71.1 emu g-1 of the mesoporous Fe3O4 nanoparticles, but it was still high enough for magnetic targeting and hyperthermia application. The evaluation on drug release performance indicated that the Fe3O4@PCM/PEG/DOX system achieved nearly zero release of DOX in vitro in body temperature, while around 80% of DOX could be released within 1.5 h at the therapeutic threshold of 42 °C or under the NIR laser irradiation for about 4 h. And a very rapid release of DOX was achieved by this system when applying an alternating magnetic field. By comparing the systems with and without PEG2000, it is revealed that the presence of PEG2000 makes DOX easy to be released from 1-tetradecanol to water, owing to its functions of increasing the solubility of DOX in 1-tetradecanol as well as decreasing the surface tension between water and 1-tetradecanol. The novel drug release system shows great potential for the development of thermo-chemotherapy of cancer treatment.
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Antibióticos Antineoplásicos/química , Preparações de Ação Retardada/química , Doxorrubicina/química , Portadores de Fármacos/química , Óxido Ferroso-Férrico/química , Nanopartículas de Magnetita/química , Preparações de Ação Retardada/síntese química , Portadores de Fármacos/síntese química , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Álcoois Graxos/química , Concentração de Íons de Hidrogênio , Hipertermia Induzida/métodos , Raios Infravermelhos , Cinética , Lasers , Nanopartículas de Magnetita/ultraestrutura , Tamanho da Partícula , Polietilenoglicóis/química , PorosidadeRESUMO
As well known, surface discharge cold plasma has efficient inactivation ability and a variety of RONS are main active particles for inactivation, but their synergistic mechanism is still not clear. Therefore, surface discharge cold plasma system was applied to treat Pseudomonas fluorescens to study bacterial inactivation mechanism and energy benefit. Results showed that energy efficiency was directly proportional to applied voltage and inversely proportional to initial concentration. Cold plasma treatment for 20 min was inactivated by approximately > 4-log10Pseudomonas fluorescens and application of â¢OH and 1O2 scavengers significantly improved survival rate. In addition, â¢OH and 1O2 destroyed cell membrane structure and membrane permeability, which promoted diffusion of RONS into cells and affecting energy metabolism and antioxidant capacity, leading to bacterial inactivation. Furthermore, accumulation of intracellular NO and ONOOH was related to infiltration of exogenous RNS, while accumulation of â¢OH, H2O2, 1O2, O2- was the result of joint action of endogenous and exogenous ROS. Transcriptome analysis revealed that different RONS of cold plasma were responsible for Pseudomonas fluorescens inactivation and related to activation of intracellular antioxidant defense system and regulation of genes expression related to amino acid metabolism and energy metabolism, which promoting cellular process, catalytic activity and other biochemical pathways.
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Gases em Plasma , Pseudomonas fluorescens , Espécies Reativas de Oxigênio , Pseudomonas fluorescens/metabolismo , Gases em Plasma/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Nitrogênio/metabolismo , Microbiologia da Água , Viabilidade Microbiana/efeitos dos fármacosRESUMO
High pressure processing is a safe and green novel non-thermal processing technique for modulating food protein aggregation behavior. However, the systematic relationship between high pressure processing conditions and protein deaggregation has not been sufficiently investigated. Major royal jelly proteins, which are naturally highly fibrillar aggregates, and it was found that the pressure level and exposure time could significantly promote protein deaggregation. The 100-200 MPa treatment favoured the deaggregation of proteins with a significant decrease in the sulfhydryl group content. Contrarily, at higher pressure levels (>400 MPa), the exposure time promoted the formation of disordered agglomerates. Notably, the inter-conversion of α-helix and ß-strands in major royal jelly proteins after high pressure processing eliminates the solvent-free cavities inside the aggregates, which exerts a 'collapsing' effect on the fibrillar aggregates. Furthermore, the first machine learning model of the high pressure processing conditions and the protein deaggregation behaviour was developed, which provided digital guidance for protein aggregation regulation.
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Ácidos Graxos , Proteínas de Insetos , Pressão , Agregados Proteicos , Proteínas de Insetos/química , Ácidos Graxos/química , Animais , Manipulação de Alimentos , Abelhas/químicaRESUMO
The application of novel insect proteins as future food resources in the food field has attracted more and more attention. In this study, a biodegradable antibacterial food packaging material with beneficial mechanical properties was developed using Tenebrio molitor larvae protein (TMP), chitosan (CS) and propolis ethanol extract (PEE) as raw materials. PEE was uniformly dispersed in the film matrix and the composite films showed excellent homogeneity and compatibility. There are strong intermolecular hydrogen bond interactions between CS, TMP, and PEE in the films, which exhibit the structure characteristics of amorphous materials. Compared with CS/TMP film, the addition of 3 % PEE significantly enhanced the elongation at break (34.23 %), water vapor barrier property (22.94 %), thermal stability (45.84 %), surface hydrophobicity (20.25 %), and biodegradability of the composite film. The composite film has strong antioxidant and antimicrobial properties, which were enhanced with the increase of PEE content. These biodegradable films offer an eco-friendly end-of-life option when buried in soil. Composite films can effectively delay the spoilage of strawberries and extend the shelf life of strawberries. Biodegradable active packaging film developed with insect protein and chitosan can be used as a substitute for petroleum-based packaging materials, and has broad application prospects in the field of fruits preservation.
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Quitosana , Embalagem de Alimentos , Proteínas de Insetos , Larva , Própole , Tenebrio , Quitosana/química , Quitosana/farmacologia , Embalagem de Alimentos/métodos , Animais , Tenebrio/química , Própole/química , Própole/farmacologia , Larva/efeitos dos fármacos , Proteínas de Insetos/química , Antibacterianos/farmacologia , Antibacterianos/química , Etanol/química , Antioxidantes/química , Antioxidantes/farmacologia , Interações Hidrofóbicas e HidrofílicasRESUMO
With growing concerns about postharvest spoilage of fruits, higher requirements have been placed on high-performance and sustainable active packaging materials. In this study, we prepared curcumin-based functional composite films using chitosan (CS) and Tenebrio molitor larvae protein (TMP) as the substrates. The effects of curcumin concentration on the structural and physicochemical properties of the composite films were determined. Curcumin was equally distributed in the polymer film through physical interactions. Furthermore, the curcumin composite film with 0.3 % addition exhibited a 27.39 % increase in elongation at break (EBA), a 37.04 % increase in the water vapor barrier, and strong UV-blocking properties and antioxidant activity compared with the control film (CS/TMP). The degradation experiment of the composite film on natural soil revealed that the composite film exhibited good biodegradability and environmental protection. Furthermore, the applicability of functional composite films for preserving blueberries was investigated. Compared with the control film and polyethylene (PE) films, the prepared composite films packaging treatment reduced the decay rate and weight loss rate of blueberries during storage, delayed softening and aging, and maintained the quality of blueberries. Using sustainable protein resources (TMP) and natural polysaccharides as packaging materials provides an economically, feasible and sustainable way to achieve the functional preservation of biomass materials.
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Antioxidantes , Mirtilos Azuis (Planta) , Quitosana , Curcumina , Embalagem de Alimentos , Conservação de Alimentos , Larva , Tenebrio , Animais , Quitosana/química , Quitosana/farmacologia , Curcumina/química , Curcumina/farmacologia , Tenebrio/química , Tenebrio/efeitos dos fármacos , Embalagem de Alimentos/métodos , Mirtilos Azuis (Planta)/química , Antioxidantes/farmacologia , Antioxidantes/química , Conservação de Alimentos/métodos , Larva/efeitos dos fármacos , Proteínas de Insetos/químicaRESUMO
Incorrect use of neonicotinoid pesticides poses a serious threat to human and pollinator health, as these substances are commonly present in bee products and even drinking water. To combat this threat, the study developed a new method of degrading the pesticide imidacloprid using surface discharge cold plasma oxidation technology. The study showed that this method achieved a very high efficiency of imidacloprid degradation of 91.4%. The main reactive oxygen species (H2O2, O3, ·OH, O2-, 1O2) effectively participated in the decomposition reaction of imidacloprid. Reactive oxygen species were more sensitive to the structure of the nitroimine group. Density functional theory (DFT) further explored the sites of reactive oxygen species attack on imidacloprid and revealed the process of energy change of attacking imidacloprid. In addition, a degradation pathway for imidacloprid was proposed, mainly involving reactive oxygen species chemisorption, a ring-opening intermediate, and complete cleavage of the nitroimine group structure. Model predictions indicated that acute oral and developmental toxicity were significantly reduced after cold plasma treatment, as confirmed by insect experiments. Animal experiments have shown that plasma treatment reduces imidacloprid damage to mice hippocampal tissue structure and inhibits the reduction of brain-derived neurotrophic factor content, thus revealing the detoxification mechanism of the body.
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Inseticidas , Praguicidas , Gases em Plasma , Humanos , Abelhas , Animais , Camundongos , Inseticidas/química , Espécies Reativas de Oxigênio , Estrutura Molecular , Peróxido de Hidrogênio , Neonicotinoides/química , Nitrocompostos/química , Nitrocompostos/farmacologiaRESUMO
A novel technique was proposed for processing silkworm pupae by combining plasma- activated water (PAW) with ultrasound (US). The microbial diversity and quality characteristics of the silkworm pupae were also evaluated. The results of the microbial diversity analysis indicated that PAW combined with US treatment significantly reduced the relative abundance of Streptococcaceae, Leuconostocaceae, and Acetobacteraceae from 32%, 18% and 16% to 27%, 11% and 11%, respectively. Microstructural analysis demonstrated that the collapse of the internal structure of chitin in silkworm pupae facilitated the release of nutrients and flavour compounds including fatty acids, water-soluble proteins (WSP), amino acids, phenolics, and volatile compounds. Furthermore, the increase in antioxidant capacity and the decrease in catalase activity and malondialdehyde content confirmed the mechanism of quality change. These findings provide new insights into the possible mechanism of PAW combined with US to improve the quality of edible insects.
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Bombyx , Pupa , Água , Animais , Pupa/microbiologia , Água/química , Bombyx/química , Ondas Ultrassônicas , Fenômenos Químicos , Antioxidantes/química , Antioxidantes/farmacologia , BiodiversidadeRESUMO
High reactive nitrogen (N) emissions due to anthropogenic activities in China have led to an increase in N deposition and ecosystem degradation. The Chinese government has strictly regulated reactive N emissions since 2010, however, determining whether N deposition has reduced requires long-term monitoring. Here, we report the patterns of N deposition at a rural forest site (Qingyuan) in northeastern China over the last decade. We collected 456 daily precipitation samples from 2014 to 2022 and analysed the temporal dynamics of N deposition. NH4+-N, NO3--N, and total inorganic N (TIN) deposition ranged from 10.5 ± 3.5 (mean ± SD), 6.1 ± 1.6, and 16.6 ± 4.7 kg N ha-1 year-1, respectively. Over the measurement period, TIN deposition at Qingyuan decreased by 55 %, whereas that in comparable sites in East Asia declined by 14-34 %. We used a random forest model to determine factors influencing the deposition of NH4+-N, NO3--N, and TIN during the study period. NH4+-N deposition decreased by 60 % because of decreased agricultural NH3 emissions. Furthermore, NO3--N deposition decreased by 42 %, due to reduced NOx emissions from agricultural soil and fossil fuel combustion. The steep decline in N deposition in northeastern China was attributed to reduced coal consumption, improved emission controls on automobiles, and shifts in agricultural practices. Long-term monitoring is needed to assess regional air quality and the impact of N emission control regulations.
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In this study, the cholesterol (CH)-lowering behavioral mechanisms and drivers of condensed tannins (CTs) were revealed using a molecular aggregation theoretical model combined with in vitro experiments, as well as the CH-lowering effects of CTs validated based on animal experiments. Theoretical model results indicated that CTs can spontaneously aggregate to form supramolecular systems, can break CH micelles and form larger aggregates, a behavior driven by van der Waals forces and hydrogen bonds; DLS and TEM results confirmed that the presence of CH leads to a larger particle size of CTs and the formation of large aggregates; thermodynamic analysis and ITC revealed that the adsorption of CH by CTs is a spontaneous reaction driven by hydrogen bonds and hydrophobic forces; Animal experiments and fecal biochemical parameters further confirmed that the intake of CTs can reduce CH absorption and promotes CH excretion. Overall, this study reveals the CH-lowering behavioral mechanism of CTs from the perspective of molecular aggregation behavior.
Assuntos
Micelas , Proantocianidinas , Animais , Proantocianidinas/química , Colesterol/química , TermodinâmicaRESUMO
Increasing evidence suggests that royal jelly (RJ) has exceptional biological properties, and that major royal jelly proteins (MRJPs) are the key active factors in RJ. The objective of this study was to compare the difference in the protein content between RJ and MRJPs using non-labeled, quantitative proteomics technology, and to investigate the adjustment features and mechanisms of MRJPs on murine immune functions and the composition of intestinal flora in cyclophosphamide-treated mice. Results showed that, during the process of extracting MRJPs, the ratio of the protein types in the main protein and other proteins decreased significantly, except for MRJP1 and MRJP7, which demonstrated that an enriching effect of MRJP1 and MRJP7 was present during the extraction process. Cyclophosphamide-induced mice were orally administered MRJPs. Results showed that the middle-dose group, which received 0.25 g/(kg·bw) of royal jelly main protein, demonstrated a clear impact on the development of the spleen and liver, the quantity of peripheral blood leukocytes, immunoglobulin content, immune factor level, and the proliferation ability of spleen lymphocytes. A 16S rRNA high-throughput sequencing technology analysis showed that MRJPs could improve the component and richness of intestinal flora and raise the immunity of mice. The above-mentioned results indicated that the application of MRJPs is very likely to have an advantage effect on murine immune functions.
Assuntos
Microbioma Gastrointestinal , Camundongos , Animais , Abelhas/genética , RNA Ribossômico 16S , Proteínas de Insetos/metabolismo , Ácidos Graxos/metabolismo , ImunidadeRESUMO
Incorporating phase change capsules into polymeric matrices is an effective approach for developing flexible composites with both heat storage capacity and good thermal reliability, while the interfacial heat conductance between the capsules and the matrix has seldom been considered. Herein, paraffin@SiO2 nanocapsules synthesized by an interfacial polycondensation process using a basic catalyst were incorporated into a polydimethylsiloxane matrix for the first time to prepare phase change composites at different loadings. Furthermore, the composites containing the nanocapsules were systematically compared with the composites containing the paraffin@SiO2 microcapsules synthesized using an acidic catalyst. It is shown that, at every identical mass fraction, the composites containing the nanocapsules not only possessed larger latent heat than those containing the microcapsules, but also exhibited higher thermal conductivity and lower hardness. The enhancement in thermal conductivity as well as the decline in hardness for the composite containing the nanocapsules are revealed to originate from a larger amount of hydroxyl groups at the surfaces of the nanocapsules than the microcapsules, which could form more hydrogen bonds with the polymer matrix. This bonding favored the interfacial heat conductance between the nanocapsules and the matrix together with decreasing the crosslinking density of the matrix. Subsequently, composites with enhanced thermal conductivity were developed by combining the nanocapsules with a BN filler. By evaluating the performance for chip heat dissipation, it was found that, when the chip was heated at a power of 10 W, the incorporation of the paraffin@SiO2 nanocapsules at a loading of 36 wt% into the polymer matrix made a remarkable decrease in the chip equilibrium temperature by 31.7 °C, and a further decline by 8.9 °C occurred when combined with 16 wt% BN. This work sheds light on facilitating the interfacial heat conductance between phase change capsules and the polymer matrix by hydrogen bonding.
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Effect of post-harvest ripening on cell wall polysaccharides nanostructures, water status, physiochemical properties of peaches and drying behavior under hot air-infrared drying was evaluated. Results showed that the content of water soluble pectins (WSP) increased by 94 %, while the contents of chelate-soluble pectins (CSP), Na2CO3-soluble pectins (NSP) and hemicelluloses (HE) decreased during post-harvest ripening by 60 %, 43 %, and 61 %, respectively. The drying time increased from 3.5 to 5.5 h when the post-harvest time increased from 0 to 6 days. Atomic force microscope analysis showed that depolymerization of hemicelluloses and pectin occurred during post-harvest ripening. Time Domain -NMR observations indicated that reorganization of cell wall polysaccharides nanostructure changed water spatial distribution and cell internal structure, facilitated moisture migration, and affected antioxidant capacity of peaches during drying. This leads to the redistribution of flavor substances (heptanal, n-nonanal dimer and n-nonanal monomer). The current work elucidates the effect of post-harvest ripening on the physiochemical properties and drying behavior of peaches.
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Nanoestruturas , Prunus persica , Água , Antioxidantes , Polissacarídeos , Parede Celular , PectinasRESUMO
Based on the concept of circular economy, citrus peel was considered a valuable source of bioactive compounds for high-value foods. Electrohydrodynamic (EHD) drying is a novel technology appropriated for the dehydration of heat-sensitive products such as citrus peel. In current work, EHD drying of citrus peel was performed based on alternating current (AC) or direct current (DC) sources at various voltage levels (9, 18, 27, 36, and 45 kV). The effect of EHD on drying characteristics, water retention capacity, enzyme inactivation, phytochemical contents (phenolic compounds and carotenoids), and volatile compounds of citrus peel were evaluated and compared. Results showed that the drying time in the AC electric field was shorter compared to DC electric field at the same applied voltages due to the polarization layer formed by unipolar charges. The applied voltage determined electric field strength as well as the degree of tissue collapse and cell membrane rupture. EHD elucidated the transformation and degradation of phytochemicals including phenolic compounds, carotenoids, and volatile composition in proportion to the applied voltage. The findings indicate that EHD drying with AC improves drying behaviors, inactivates enzymes, and retains the phytochemical properties of citrus peel.