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1.
iScience ; 27(4): 109474, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38551000

RESUMO

Abnormal accumulation of hydrogen peroxide (H2O2) in the tumor microenvironment is associated with altered metabolism, abnormal proliferation of tumor cells, and changes in the tumor microenvironment. Based on this phenomenon, we have developed manganese-doped zeolitic imidazolate frameworks (Mn-ZIF) nanozymes, which exhibit superior peroxidase (POD)-like activity and enhanced cytotoxicity. Inside the tumor, the H2O2 is catalyzed by Mn-ZIF nanozymes through the Fenton reaction to generate more potent hydroxyl radicals (·OH), further increasing the local reactive oxygen species (ROS) levels in tumor cells and inducing tumor cell death. Meanwhile, the removal of H2O2 in the tumor microenvironment reduces tumor proliferation. We have confirmed the anti-tumor effect of these particles in an in situ osteosarcoma (OS) model, providing a direction for the future design of hybrid nanozyme drug delivery systems.

2.
Langmuir ; 40(13): 7242-7248, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38501957

RESUMO

The metal-thiol interface is ubiquitous in nanotechnology and surface chemistry. It is not only used to construct nanocomposites but also plays a decisive role in the properties of these materials. When organothiol molecules bind to the gold surface, there is still controversy over whether sulfhydryl groups can form disulfide bonds and whether these disulfide bonds can remain stable on the gold surface. Here, we investigate the intrinsic properties of sulfhydryl groups on the gold surface at the single-molecule level using a scanning tunneling microscope break junction technique. Our findings indicate that sulfhydryl groups can react with each other to form disulfide bonds on the gold surface, and the electric field can promote the sulfhydryl coupling reaction. In addition to these findings, ultraviolet irradiation is used to effectively regulate the coupling between sulfhydryl groups, leading to the formation and cleavage of disulfide bonds. These results unveil the intrinsic properties of sulfhydryl groups on the gold surface, therefore facilitating the accurate construction of broad nanocomposites with the desired functionalities.

3.
Heliyon ; 10(5): e27167, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38444496

RESUMO

Verification of the geographical origin of rapeseed oil is essential to protect consumers from fraudulent products. A prospective study was conducted on 45 samples from three rapeseed oil-producing areas in Qinghai Province, which were analyzed by GC-FID and GC-MS. To assess the accuracy of the prediction of origin, classification models were developed using PCA, OPLS-DA, and LDA. It was found that multivariate analysis combined with PCA separate 96% of the samples, and the correct sample discrimination rate based on the OPLS-DA model was over 98%. The predictive index of the model was Q2 = 0.841, indicating that the model had good predictive ability. The LDA results showed highly accurate classification (100%) and cross-validation (100%) rates for the rapeseed oil samples, demonstrating that the model had strong predictive capacity. These findings will serve as a foundation for the implementation and advancement of origin traceability using the combination of fatty acid, phytosterol and tocopherol fingerprints.

4.
Clin Lab ; 70(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38469775

RESUMO

BACKGROUND: The aim of this study was to verify the analytical performance of the UD90DT electrochemiluminescence immunoassay system (the UD90DT system) for measuring high-sensitivity cardiac troponin T (hs-cTnT). METHODS: According to the Clinical and Laboratory Standards Institute guidelines, the imprecision, linearity, reference interval, limit of blank (LoB), limit of detection (LoD), and functional sensitivity (FS) of hs-cTnT using the UD90DT system were verified. The trueness was validated using the Proficiency Testing (PT) materials. RESULTS: The within-run and between-run coefficients of variations (CVs) of two hs-cTnT levels were 7.2% and 1.5%, and 7.1% and 2.6%, respectively. The biases of the PT samples (n = 6) all fell within the allowable total error. The linearity satisfied the requirements, with a slope of 0.9963 and an R12 value of 0.9998. The hs-cTnT levels of the healthy volunteers (n = 20) ranged from 3.0 ng/L to 7.7 ng/L. All blank calibrator measurements (n = 20) fell within the LoD claim, and none of the samples (n = 25) had a LoB value ≤ 3.0 ng/L. The FS was 5.3 ng/L. Furthermore, a good correlation between the UD90DT system and the Cobas e 601 module was observed for hs-cTnT. CONCLUSIONS: The analytical performance of hs-cTnT using the UD90DT system is acceptable and satisfies clinical needs.


Assuntos
Testes Imunológicos , Troponina T , Humanos , Limite de Detecção , Imunoensaio , Biomarcadores
5.
Data Brief ; 53: 110130, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38348317

RESUMO

This dataset reports microstructure and mechanical property features of AlSi10Mg manufactured using laser powder bed fusion over a wide range of processing conditions. Samples were fabricated with different combinations of laser power, scan speed, and hatch spacing to probe dense regimes as well as porous samples resulting from keyholing and lack of fusion. Pore and grain/sub-grain features for each processing set were quantified. Sample porosity was measured using Archimedes density measurements and X-ray computed tomography (XCT). XCT was also used to characterize the surface roughness of samples along with pore size and morphology. Electron backscatter diffraction (EBSD) was used to characterize the grain size and morphology while scanning electron microscope (SEM) imaging and was used to measure solidification cell size. Uniaxial tension tests were performed to ascertain yield and ultimate tensile strengths, elongation, and elastic modulus, and microhardness was measured using Vickers indentation.

6.
Diabetes Metab Syndr Obes ; 17: 809-823, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38380275

RESUMO

The incidences of thyroid cancer and diabetes are rapidly increasing worldwide. The relationship between thyroid cancer and diabetes is a popular topic in medicine. Increasing evidence has shown that diabetes increases the risk of thyroid cancer to a certain extent. This mechanism may be related to genetic factors, abnormal thyroid-stimulating hormone secretion, oxidative stress injury, hyperinsulinemia, elevated insulin-like growth factor-1 levels, abnormal secretion of adipocytokines, and increased secretion of inflammatory factors and chemokines. This article reviews the latest research progress on the relationship between thyroid cancer and diabetes, including the association between diabetes and the risk of developing thyroid cancer, its underlying mechanisms, and potential anti-thyroid cancer effects of hypoglycemic drugs. It providing novel strategies for the prevention, treatment, and improving the prognosis of thyroid cancer.

7.
J Food Prot ; 87(2): 100221, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38215978

RESUMO

Flaxseed oil is an important source of vegetable oil with a polyunsaturated fatty acid. It is significant to establish a method to quickly identify adulterated flaxseed oil. In the present study, the qualitative and quantitative analysis of phytosterol of flaxseed oil from different varieties and different production areas in the Qinghai area was first performed by gas chromatography-mass spectrometry (GC-MS) and the phytosterol standard profile of flaxseed oil was established. Then, a combination of similarity evaluation and cluster analysis was used to distinguish pure flaxseed oil from flaxseed oil adulterated with concentrations of 10-50% rapeseed oil, peanut oil, sunflower oil, and sesame oil, and discriminant analysis was used to identify the types of adulterated flaxseed oil. The results showed that similarity evaluation combined with cluster analysis can distinguish pure and adulterated flaxseed oil when the concentration of the adulterant was greater than 10%. Discriminant analysis models accurately identified the types of adulterating oil in flaxseed oil when the concentration of rapeseed, peanut, or sunflower oil was greater than 20%, and that of sesame oil was greater than 30%. This study shows that the determination of the phytosterol composition and chemometrics is a valuable tool to evaluate the purity of flaxseed oil.


Assuntos
Óleo de Semente do Linho , Fitosteróis , Cromatografia Gasosa-Espectrometria de Massas , Óleo de Gergelim/análise , Óleo de Gergelim/química , Quimiometria , Óleos de Plantas , Óleo de Girassol
8.
Nat Commun ; 14(1): 7695, 2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38001141

RESUMO

The transformation from one compound to another involves the breaking and formation of chemical bonds at the single-bond level, especially during catalytic reactions that are of great significance in broad fields such as energy conversion, environmental science, life science and chemical synthesis. The study of the reaction process at the single-bond limit is the key to understanding the catalytic reaction mechanism and further rationally designing catalysts. Here, we develop a method to monitor the catalytic process from the perspective of the single-bond energy using high-resolution scanning tunneling microscopy single-molecule junctions. Experimental and theoretical studies consistently reveal that the attack of a halogen atom on an Au atom can reduce the breaking energy of Au-S bonds, thereby accelerating the bond cleavage reaction and shortening the plateau length during the single-molecule junction breaking. Furthermore, the distinction in catalytic activity between different halogen atoms can be compared as well. This study establishes the intrinsic relationship among the reaction activation energy, the chemical bond breaking energy and the single-molecule junction breaking process, strengthening our mastery of catalytic reactions towards precise chemistry.

9.
Clin Lab ; 69(10)2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37844061

RESUMO

BACKGROUND: The aim was to explore the diagnostic value of serum free light chain (sFLC) and other laboratory indicators for the patients with light chain multiple myeloma (LCMM). METHODS: We performed a retrospective study including 82 LCMM cases and 43 healthy subjects as the observation and control groups, respectively. The observation group was further divided into two subgroups: κ- and λ-type LCMM. Sixteen quantitative indicators were collected and the difference among groups was compared. We also evaluated the positive detection rate (PDR) of four qualitative indicators for M protein detection. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of sixteen indicators. RESULTS: Fourteen indicators showed statistical differences between the control group and κ- or λ-type LCMM subgroup. The κ and λ sFLC ratio (rFLC) and the difference between κ and λ FLC (dFLC) showed differences among the three groups. Among the four qualitative indicators of M protein detection, rFLC showed the highest PDR for both κ- and λ-type LCMM. Among the three combinations with rFLC or uIFE did not show statistical differences. ROC curve analysis indicated a relatively high diagnostic value of dFLC for both κ- and λ-type LCMM. CONCLUSIONS: We should be vigilant about the missed diagnosis by observing the changes of MM-related indicators, particularly dFLC and the six other indicators with high diagnostic value. rFLC can improve the diagnostic ability of LCMM.


Assuntos
Mieloma Múltiplo , Humanos , Mieloma Múltiplo/diagnóstico , Estudos Retrospectivos , Cadeias Leves de Imunoglobulina , Curva ROC , Laboratórios , Cadeias kappa de Imunoglobulina , Cadeias lambda de Imunoglobulina
10.
Polymers (Basel) ; 15(18)2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37765516

RESUMO

In order to study the temperature variation and flow characteristics in the twin-screw reactive extrusion process of synthetizing glycidyl azide polymer-based energetic thermoplastic elastomer (GAP-ETPE), a non-isothermal simulation and a safety analysis were carried out. Firstly, based on the synthesis principle of GAP-ETPE, a mechanical sensitivity test, viscosity test and differential scanning calorimetry (DSC) of GAP-ETPE were carried out. Secondly, a three-dimensional physical model of the intermeshing co-rotating conveying element was established by Gambit. A three-dimensional non-isothermal numerical simulation of the conveying and kneading elements was carried out using FLUENT 19.0 software. The temperature, pressure and shear stress field of conveying and kneading elements with different staggered angles were analyzed and compared. The results show that the maximum temperature of the kneading element is always slightly higher than that of the conveying element at the same rotational speed, but the average temperature in the flow channel is always slightly higher than that of the kneading element. The inlet and outlet pressure difference of the kneading elements with a 90° offset angle is the smallest and the safety is the highest. The shear stress in the flow channel of the conveying element is higher than that of the kneading element as a whole, but the shear stress near the outlet of the 90° kneading element is higher than that in the flow channel of the conveying element. Among the kneading elements, the 90° kneading element has the strongest dispersing and mixing ability, followed by the 60° and 45° kneading elements. According to the thermal and physical parameters of the material, the ignition response time is approximately 6 s, which provides a theoretical guide for the safety design of the GAP-ETPE twin-screw extruder.

11.
Geriatr Nurs ; 51: 369-377, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37127013

RESUMO

BACKGROUND: To date quantitative meta-analysis with large samples to investigate the effects and potential moderators of physical activity (PA) on executive function (EF) in older adults with dementia is insufficient. Therefore, we conducted this meta-analysis. DESIGN: Meta-analysis of randomized controlled trials (RCTs). PARTICIPANTS: Old people with Alzheimer's disease (AD) or related dementia of varying types and severity as the primary diagnosis. METHODS: PubMed, Web of Science, the Cochrane Library and Embase databases were searched for relevant studies published from 01 January, 2010 to 01 March, 2022. The results of executive function were reported in all RCTs. Random-effects meta-analysis was used to calculate the size of effects. Subgroup analyses of three moderators (including the specific sub-domains of EF, exercise prescription variables, and sample characteristics) were performed. RESULTS: Eighteen RCTs were included with a combined sample size of 1366. Overall, PA interventions improved overall EF (standardized mean difference [SMD]=0.23, 95% confidence interval [CI] 0.05 to 0.41, p<0.05). The EF sub-domain "planning" was significant moderator (SMD=0.31, 95%CI 0.11 to 1.51, p<0.01), but inhibitory control, working memory and cognitive flexibility were not significant. Regarding exercise prescription variables, type of resistance training; moderate intensity; total duration ≤24 weeks and short (once or twice a week) frequency improved overall EF performance. Session length may be a moderator. Regarding sample characteristics, old-old, AD and both dementia and AD had significant benefits. CONCLUSIONS AND IMPLICATIONS: EF in older adults with AD or related dementia benefited from physical activity, and the benefit was affected by the type, intensity, total duration, frequency of exercise. Physical activity can be an alternative intervention in aging patients with dementia, to improve EF performance or prevent or EF decline.


Assuntos
Doença de Alzheimer , Função Executiva , Humanos , Idoso , Ensaios Clínicos Controlados Aleatórios como Assunto , Exercício Físico , Terapia por Exercício , Doença de Alzheimer/terapia , Cognição
12.
Small ; 19(35): e2301288, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37178409

RESUMO

Metal aerogels (MAs) are emerging porous materials displaying unprecedented potential in catalysis, sensing, plasmonic technologies, etc. However, the lack of efficient regulation of their nano-building blocks (NBBs) remains a big hurdle that hampers the in-depth investigation and performance enhancement. Here, by harmonizing composition and ligand effects, Pt- and Bi-based single- and bimetallic aerogels bearing NBBs of controlled dimensions and shapes are obtained by facilely tuning the metal precursors and the applied ligands. Particularly, by further modulating the electronic and optic properties of the aerogels via adjusting the content of the catalytically active Pt component and the semiconducting Bi component, both the electrocatalytic and photoelectrocatalytic performance of the Pt-Bi aerogels can be manipulated. In this light, an impressive catalytic performance for electro-oxidation of methanol is acquired, marking a mass activity of 6.4-fold higher under UV irradiation than that for commercial Pt/C. This study not only sheds light on in situ manipulating NBBs of MAs, but also puts forward guidelines for crafting high-performance MAs-based electrocatalysts and photoelectrocatalysts toward energy-related electrochemical processes.

13.
Sci Adv ; 9(22): eadg4346, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37256956

RESUMO

In aromatic systems with large π-conjugated structures, armchair and zigzag configurations can affect each material's electronic properties, determining their performance and generating certain quantum effects. Here, we explore the intrinsic effect of armchair and zigzag pathways on charge transport through single hexabenzocoronene molecules. Theoretical calculations and systematic experimental results from static carbon-based single-molecule junctions and dynamic scanning tunneling microscope break junctions show that charge carriers are preferentially transported along the hexabenzocoronene armchair pathway, and thus, the corresponding current through this pathway is approximately one order of magnitude higher than that through the zigzag pathway. In addition, the molecule with the zigzag pathway has a smaller energy gap. In combination with its lower off-state conductance, it shows a better field-effect performance because of its higher on-off ratio in electrical measurements. This study on charge transport pathways offers a useful perspective for understanding the electronic properties of π-conjugated systems and realizing high-performance molecular nanocircuits toward practical applications.

14.
Adv Mater ; 35(28): e2301876, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37022284

RESUMO

The electronic characteristics of organic optoelectronic materials determine the performance of corresponding devices. Clarifying the relationship between molecular structure and electronic characteristics at the single-molecule level can help to achieve high performance for organic optoelectronic materials and devices, especially for organic photovoltaics. In this work, a typical acceptor-donor-acceptor (A-D-A)-type molecule is explored by combining theoretical and experimental studies to reveal the intrinsic electronic characteristics at the single-molecule level. Specifically, the A-D-A-type molecule with 1,1-dicyano methylene-3-indanone (INCN) acceptor units exhibits an enhanced conductance in single-molecule junctions when compared with the control donor molecule, because the acceptor units of the A-D-A-type molecule contribute additional transport channels. In addition, through opening the S∙∙∙O noncovalent conformational lock by protonation to expose the -S anchoring sites, the charge transport of the D central part is detected, proving that the conductive orbitals contributed by the INCN acceptor groups can penetrate the whole A-D-A molecule. These results provide important insights into the development of high-performance organic optoelectronic materials and devices toward practical applications.


Assuntos
Eletrônica , Indanos , Condutividade Elétrica
15.
Comput Assist Surg (Abingdon) ; 28(1): 2195078, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37017230

RESUMO

Lung tumor is the first malignant tumor with the highest mortality, but only no more than one-third of patients can be treated by surgical resection. Microwave ablation (MWA) has become a new adjuvant therapeutic mean for lung tumors because of its low trauma, short treatment time, large ablation volume and wide application range. However, the treatment parameters of MWA, such as input power and ablation time, still depend on the doctors' experience, which leads to the ineffectiveness of MWA. Therefore, the accurate modeling of temperature distribution of lung tumor MWA has become a significant technical problem to be solved. Recent research was devoted to personalized characterization of lung tumor parameters, finite element analysis of temperature distribution in MWA and accurate ablation effect evaluation. In this paper, a review of the recently obtained results and data will be presented and discussed.


Assuntos
Técnicas de Ablação , Neoplasias Pulmonares , Humanos , Temperatura , Micro-Ondas/uso terapêutico , Neoplasias Pulmonares/cirurgia , Neoplasias Pulmonares/patologia , Simulação por Computador
16.
Int Wound J ; 20(7): 2618-2625, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36905211

RESUMO

A meta-analysis study to assess the effect of ultrasound-supported wound debridement (USSD) in subjects with diabetic foot ulcer (DFU). A comprehensive literature examination till January 2023 was implemented and 1873 linked studies were appraised. The picked studies contained 577 subjects with DFUs in the studies' baseline, 282 of them were using USSD, 204 were using standard care, and 91 were using a placebo. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of USSD in subjects with DFUs by the dichotomous styles and a fixed or random effect model. The USSD applied to DFU caused a significantly higher wound healing rate compared with the standard care (OR, 3.08; 95% CI, 1.94-4.88, P < .001) with no heterogeneity (I2  = 0%) and the placebo (OR, 7.61; 95% CI, 3.11-18.63, P = .02) with no heterogeneity (I2  = 0%). The USSD applied to DFUs caused a significantly higher wound healing rate compared with the standard care and the placebo. Though precautions should be taken when commerce with the consequences as all of the picked studies for this meta-analysis was with low sample sizes.


Assuntos
Diabetes Mellitus , Pé Diabético , Humanos , Desbridamento , Pé Diabético/terapia , Pé Diabético/diagnóstico , Cicatrização , Ultrassonografia , Razão de Chances
17.
Int Wound J ; 20(7): 2626-2633, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36994798

RESUMO

A meta-analysis study to assess the effect of honey dressing (HD) in the management of diabetic foot ulcer (DFU). A comprehensive literature examination till January 2023 was implemented and 1794 linked studies were appraised. The picked studies contained 882 subjects with DFUs were in the picked studies' baseline, 424 of them were using HD, and 458 were using a control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of HD in the management of DFUs after DFU by the dichotomous and continuous styles and a fixed or random model. The HD applied to DFUs caused a significantly higher wound healing rate (OR, 2.06; 95% CI, 1.45-2.93, P < .001) and lower wound healing time (MD, -10.42; 95% CI, -16.27- -4.58, P < .001) compared with the control. The HD applied to DFUs caused a significantly higher wound healing rate and lower wound healing time compared with the control. Although precautions should be taken when commerce with the consequences since most of the picked studies for this meta-analysis was with low sample sizes.


Assuntos
Diabetes Mellitus , Pé Diabético , Mel , Humanos , Pé Diabético/terapia , Pé Diabético/diagnóstico , Curativos Hidrocoloides , Cicatrização
18.
Chin Herb Med ; 15(1): 86-93, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36875432

RESUMO

Objective: To examine the protective effects of hydroxysafflor yellow A (HSYA) against the senescence of mesenchymal stem cells (MSCs) induced by d-galactose (d-gal) in vitro, and investigate the potential mechanism involved. Methods: Grouping experiment, Normal control (NC) group: conventional culture with complete medium; Senescence group: MSCs were cultured for 48 h with complete medium containing 10 g/L d-gal; HSYA group: on the basis of senescence induction, HSYA with the suitable concentration was used to protect MSCs. The key experimental indices associated with oxidative stress, inflammatory response, cell senescence, proliferation and apoptosis were measured through chemical colorimetry, ß-galactosidase staining, EdU incorporation and flow cytometry, respectively. The relative quantity (RQ) of proteins related closely to cell proliferation, apoptosis, and NF-κB signaling were measured by Western blotting. Results: As compared with Senescence group, treatment with HSYA (120 mg/L) effectively ameliorated the adverse situation of MSCs. Oxidation stress and inflammation along with d-Gal induction was dramatically alleviated in MSCs; The ß-Gal-positive staining indicated that MSC senescence was significantly mitigated; The proliferative capability of MSCs was significantly increased by up-regulating PCNA and inhibiting p16 expression; The anti-apoptotic effect on MSCs was exerted by down-regulating the RQ of cleaved Caspase-3 and Bax; The activity of NF-κB signaling in MSCs was notably suppressed through inhibiting phosphorylation of IKKß and p65. Conclusion: HSYA (120 mg/L) significantly delayed the d-Gal-induced senescence process in MSCs through attenuating inflammatory reaction and oxidative stress, and suppressing the activity of NF-κB signaling.

19.
Front Plant Sci ; 14: 1143439, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36993862

RESUMO

Raspberries are highly nutritious and have powerful antioxidant properties, making them functional berries with positive effects on physiological functioning. However, there is limited information available on the diversity and variability of metabolites in raspberry and its parts, especially in plateau raspberries. To address this, commercial raspberries and their pulp and seeds from two plateaus in China were subjected to LC-MS/MS-based metabolomics analysis and evaluated for antioxidant activity using four assays. A metabolite-metabolite correlation network was established based on antioxidant activity and correlation analysis. The results showed that 1661 metabolites were identified and classified into 12 categories, with significant variations in composition between the whole berry and its parts from different plateaus. Flavonoids, amino acids and their derivatives, and phenolic acids were found to be up-regulated in Qinghai's raspberry compared to Yunnan's raspberry. The main differently regulated pathways were related to flavonoid, amino acid, and anthocyanin biosynthesis. The antioxidant activity of Qinghai's raspberry was stronger than Yunnan's raspberry, and the order of antioxidant capacity was seed > pulp > berry. The highest FRAP (420.31 µM TE/g DW) values was found in the seed of Qinghai's raspberry. Overall, these findings suggest that the environment in which the berries grow can affect their chemical composition, and comprehensive exploitation and cultivation of whole raspberry and its parts from different plateaus can lead to new opportunities for phytochemical compositions and antioxidant activity.

20.
Macromol Rapid Commun ; 44(2): e2200570, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36104160

RESUMO

Fluorinated copolymers can self-assemble in solution and form micelles with rare properties due to the peculiar behavior of fluorinated groups. However, the process description of the self-assembly is still largely phenomenological and difficult to explain due to the tendency of the fluorinated segments to segregate from both the hydrophilic and lipophilic segments, which can result in various morphologies. Herein, the controlled formation of ellipsoidal micelles, disklike micelles, and sheets by hierarchical self-assembly of triphilic main-chain-type semifluorinated alternating graft copolymers (AB)n A-g-mOEG is presented (where A represents unit of α,ω-diiodoperfluoroalkane, B represents the unit of α,ω-unconjugated diene, and mOEG represents methoxy oligo(ethylene glycol)), which are synthesized by step transfer-addition and radical-termination (START) polymerization and azide-alkyne click chemistry. Furthermore, the possible self-assembly mechanism of these micron-level aggregates is proposed, which is ascribed to the hierarchical self-assembly, crowding effect of hydrophilic chains and the interfacial tension between the fluoroalkane and alkane segments. This study can provide a facile and highly efficient approach to the synthesis of main-chain-type fluorinated graft copolymers and expand the research field for the solution self-assembly of fluorinated copolymers.


Assuntos
Micelas , Polímeros , Polímeros/química , Água/química , Polimerização , Interações Hidrofóbicas e Hidrofílicas
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