COMPOSITE INTERFACES
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2025
·
IF 2.4
Zhenyu Zhu,Xinxing Nie,Yuheng Fu,Yibo Zhang,Zhiwei Ye,Hongmei Qin,Chuanxi Xiong,Shixian Zhang
With the increasing demand for refrigeration in modern society, the environmental costs associated with traditional vapor compression refrigeration have become increasingly significant. In this context, polymer elastomers based on the elastocaloric effect have emerged as a promising alternative due to their high energy efficiency, ease of processing, and low cost. However, the elastocaloric response of current polymer elastomers still falls short of practical application levels, and effective methods to enhance the elastocaloric effect are lacking. Here, we investigated the elastocaloric effect of poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) based composites from the perspective of conformational changes through in situ testing. We demonstrated that the introduction of SiO2 increases the conformational entropy of the composites in the relaxed state while reducing it in the stretched state, resulting in greater conformational changes during deformation. With the optimal composition, the adiabatic temperature change of the composites reached −16 K, and the isothermal entropy change reached 163.1 J kg−1 K−1, representing a 30% improvement compared to SEBS. This study provides a novel approach for enhancing the elastocaloric effect of polymer elastomers, potentially advancing the commercialization of polymer-based elastocaloric refrigeration.
研究领域:
材料科学
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能源技术
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高分子化学
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
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2017
·Vol. 55
·期 18
·1373-1379
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IF 2.838
Jiao Chen,Ye Sha,Siyang Gao,Chao Teng,Xiaoliang Wang,Dongshan Zhou,Linling Li,Wei Chen,Gi Xue
Understanding the conformational changes of polymeric chains in solutions is an essential and integral part of polymer physics. By increasing the concentration of polymer solutions from dilute to semidilute regime, the critical chain overlapping has been reported at the concentration termed as C *. In this study, the associated inter- and intrachain conformational transitions in polystyrene (PS) solutions are reported. By comparing the spectroscopic intensity ratio versus concentration for an intrachain PS system, a break point was observed in good solvent which coincided with the theoretically predicted C *. Moreover, the intrachain conformation showed no obvious change below C *, while significant collapse started to occur above C *. This result reveals a new insight in polymer physics, since traditionally the size of polymer chains is considered to decrease weakly regarding the concentration change in the semidilute regime. It is important to find such an abrupt intrachain conformational transition between the dilute and semidilute solutions and provide the first experimental observation that inter- and intrachain conformational transitions are correlated to one the other. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 1373–1379
研究领域:
聚合物物理
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材料科学
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DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2024
·
IF 3.2
Ronghua Peng,Xueyou Qin,Jiawei Lin,Lingyu Wang,Songgu Wu,Junbo Gong
We designed a solvent mixture composed of carboxylic acid solvents and water as the crystallization medium for the selective preparation of three distinct γ-aminobutyric acid (GABA) conformational polymorphs (Form-I, Form-II, and the newly discovered Form-IV). By adjusting the carbon chain length and content of carboxylic acid solvents, we were able to finely tune the solvation environment, leading to the formation of the desired polymorphs. Crash-cooling crystallization experiments demonstrated that with the carbon chain length (C1–C6) and content (0–30%) of carboxylic acid increasing, the polymorphic outcomes gradually change from Form-I to Form-II and ultimately to Form-IV. Interestingly, four different conformations were observed within these three polymorphs. DFT calculation indicated that the stability order of these conformations is conformer-IVβ > conformer-IVα > conformer-II > conformer-I. Based on solution FTIR analysis and solvation free energy calculation, the solvation effect on GABA molecules diminishes with an increasing carbon chain length and content of carboxylic acid solvents. A lower solvation effect makes the desolvation process of GABA molecules much easier so that GABA molecules can undergo sufficient conformational rearrangement during the nucleation stage, thereby adopting a more stable conformation during the molecular assembly process. In this crystallization conditions, Form-IV with a more stable conformation in its crystal structure has the potential to replace Form-II and Form-I through preferential crystallization.
研究领域:
化学
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材料科学
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药物学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2018
·Vol. 20
·期 10
·7351-7360
·
IF 3.906
Shan Jin,Yongjun Hu,Pengchao Wang,Huaqi Zhan,Qiao Lu,Fuyi Liu,Liusi Sheng
Water molecules, which serve as both hydrogen bond donors and acceptors, have been found to influence the conformational landscape of gas-phase phenyl-β-D-glucopyranoside. Herein, tetrahydrofurfuryl alcohol (THFA), a sugar-like molecule without chromophores (e.g. phenyl-substitution), was used as the model sugar molecule for exploring the behaviour of water molecules on the conformational landscape of a pentose sugar such as deoxyribose. We used mass selected infrared-vacuum ultraviolet (IR-VUV) (118 nm) spectroscopy to investigate the hydrated neutral THFA and its complex cation in a supersonic jet. High level density functional theory (DFT) calculations were performed to ascertain the experimental results. The results revealed that the water molecule tends to insert into the twisted conformer at a position where two stronger intermolecular hydrogen bonds were formed by breaking the weak intramolecular interactions. We found that the twisted conformer of the hydrated neutral THFA complex is more stable than the envelope conformation, while the latter is more stable for the THFA molecule. However, the conformational landscape of the hydrated THFA complex cation did not significantly change on microsolvation with water molecules. These results indicated that the dominant structural landscape of the hydrated cationic complex is the twisted configuration with a trans-hydroxymethyl group. This finding provides valuable insight into the microsolvation of gas-phase sugar molecules.
研究领域:
化学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2023
·
IF 8.8
Xueliang Zhang,Gisele LaPointe,Yang Liu,Xiaomeng Wang,Luyao Xiao,Xiaogan Zhao,Wei Li
In this study, we evaluated the impact of Lactiplantibacillus plantarum ( L. plantarum ) with ropy and non-ropy phenotypes on gel structure and protein conformation of fermented milk. Ropy L. plantarum (T1 & CL80) secreted EPS with high molecular weight (1.41 × 10 6 , 1.19 × 10 6 Da) and intrinsic viscosity (486.46, 316.32 mL/g), effectively enhances fermented milk viscosity and water holding capacity (WHC) (65.4%, 84.6%) by forming a dense gel structure. Non-ropy L. plantarum (CSK & S-1A) fermented milk gel’s high surface hydrophobicity and free sulfhydryl content caused high hardness and low WHC. Raman spectroscopy combined with circular dichroism analysis showed that high levels of α-helix (29.32–30.31%) and random roil (23.06–25.36%) protein structures are the intrinsic factors that contribute to the difference among fermented milk gels of ropy and non-ropy strains. This study provides a basis for understanding the structural variability of fermented milk gels using ropy or non-ropy lactic acid bacteria.
研究领域:
食品科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Peilin Chen,Qingxiang You,Xin Li,Qing Chang,Yi Zhang,Baodong Zheng,Xiaoke Hu,Hongliang Zeng
In this study, the relationships between the proliferation effect of polysaccharide fractions from the citrus shrub Fortunella margarita on Bifidobacterium adolescentis ATCC 15703 and their resulting structural changes were investigated. Four polysaccharide fractions, FP20, FP40, FP60, and FP80, were obtained by graded precipitation at ethanol concentrations of 20%, 40%, 60% and 80%, respectively. The results showed that polysaccharide fractions, especially FP20, FP40, and FP60, enhanced the proliferation of B. adolescentis ATCC 15703 and their effects were better than those of FP80, inulin or glucose. Moreover, acetic acid was mainly produced during fermentation. After fermentation, the molecular weight of polysaccharide fractions decreased and the tightly structural chain conformations of FP20, FP40, and FP60 changed to highly branched structures. The prebiotic effect of these polysaccharide fractions might be related to their molecular weight and chain conformation. Thus, these polysaccharides could be used as potential prebiotics.
研究领域:
食品科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Zheng Zhang,Boyun Yang,Jiaying Zhao,Anqi Xie,Lei Feng,Yiqun Wan
Anoectochilus roxburghii (AR) has been used in food, medicine and ornamental industries for a long time. Anion exchange resin was proposed to purify the sub-fraction of water-extracted AR polysaccharide (ARPP-70), and a homogeneous polysaccharide ARPP-70a was obtained. The structural features of ARPP-70a were characterized using gas chromatography–mass spectrometry (GC–MS), nuclear magnetic resonance (NMR) spectroscopy, and high performance size exclusion chromatograph coupled with multi-angle laser light scattering (HPSEC-MALLS). The relative weight average molecular weight for ARPP-70a was determined to be 14.8 kDa, and the molar ratio of glucose to galactose was 1.0:3.2. The structure of ARPP-70a was elucidated to be glucogalactan, with backbone comprising β-1,4-linked Gal p and some α-1,4-linked Glc p . The conformation characteristics of ARPP-70a were supposed to exist as a random coil chain in 0.1 M NaNO 3 solution. Moreover, in vitro antioxidant activity assays revealed ARPP-70a exhibited appreciable antioxidant potential. To the best of our knowledge, this is the first study to obtain this type of glucogalactan, and provide systematic information on its structural and conformational properties. This study improved the understanding of the physicochemical characteristics of AR polysaccharide, which is beneficial for its further application in food and medicinal industry.
研究领域:
植物化学
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食品科学
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药理学
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DOI
PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2016
·
IF 2.624
Lei Zhou,Wei Liu,Zhiqiang Xiong,Liqiang Zou,Junping Liu,Junzhen Zhong,Jun Chen
Polyphenoloxidase (PPO) plays an important role in the browning of vegetables, fruits and edible fungi. The effects of ultrasound, malic acid, and their combination on the activity and conformation of mushroom ( Agaricus bisporus ) PPO were studied. The activity of PPO decreased gradually with the increasing of malic acid concentrations (5–60 mM). Neither medium concentrations (10, 20, 30 mM) malic acid nor individual ultrasound (25 kHz, 55.48 W/cm 2 ) treatment could remarkably inactivate PPO. However, the inactivation during their combination was more significant than the sum of ultrasound inactivation and malic acid inactivation. The inactivation kinetics of PPO followed a first-order kinetics under the combination of ultrasound and malic acid. The conformation of combination treated PPO was changed, which was reflected in the decrease of α-helix, increase of β-sheet contents and disruption of the tertiary structure. Results of molecular microstructure showed that ultrasound broke large molecular groups of PPO into small ones. Moreover, combined treatment disrupted the microstructure of PPO and molecules were connected together.
研究领域:
食品科学
·
生物化学
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DOI
高影响因子
Food Bioscience
·
2023
·
IF 5.2
Mei Bai,Jinming Dai,Wei Hu,Changzhu Li,Haiying Cui,Lin Lin
This study investigated the use of Litsea cubeba essential oil (LC-EO) as an anti-virulence agent targeting listeriolysin O (LLO) of Listeria monocytogenes ( L. monocytogenes ). The hemolysis assay showed a significant decrease in the hemolytic activity of LLO by 90.7% and 70.2% after exposure to 500 μg mL −1 LC-EO or 700 μg mL −1 citral (the main component of LC-EO), respectively. This suggested that citral plays a major role in the anti-virulence function against LLO. The experiments including UV–visible absorption spectroscopy , fluorescence quenching and three-dimensional fluorescence spectroscopy demonstrated that exposure to citral leads to significant changes in the conformation of LLO, potentially resulting in the unfolding of its structure and the formation of a ground-state complex. Synchronous fluorescence spectra analysis indicated that the binding site of citral could be the undecapeptide region of LLO. Additionally, the results of molecular docking and the acid-base effect experiment of different aldehydes and phenols revealed that the cysteine residue of LLO and the α, β-unsaturated aldehyde of citral are likely to form a covalent bond through Michael addition . This interaction is believed to be the primary reason for the loss of hemolytic activity. As a result, this work provides a new approach for the development of LLO-targeting anti-virulence agents and holds promise for expanding the application of LC-EO in the field of food microbiological safety.
研究领域:
食品科学
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微生物学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Zhixiang Cai,Hongbin Zhang
The chain conformational change in curdlan during carboxymethylation was investigated using nuclear magnetic resonance (NMR), circular dichroism (CD) spectroscopy, and atomic force microscopy (AFM). The distributions of carboxymethyl substituents within anhydroglucose unit (AGU) of CMCD were found to follow the order of OH (6) > OH (4) > OH (2) for CMCD with a low DS and OH (6) > OH (2) > OH (4) for CMCD with relatively high DS. The increased carboxymethylation level induced the chain conformation transition of curdlan from triple helix to random coil in water. The DS of 0.25 was the critical value of chain conformation transition, below which CMCD chains were triple helices. For DS larger than 0.25, CMCD existed in the state of random coils. The intermolecular hydrogen bonding between C2 hydroxyls in AGU sustained the triple helical conformation and stiffness of the polymer chain, which weakened with the increase in DS.
研究领域:
生物化学
·
高分子科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Zhijiang Rong,Wei Guo,Haotian Liang,Huan Lv,Hua Guo,Yi Zhang,Bo Zhang,Chunyan Hao,Xianjun Liu,Hongyan Sun,Yifan Gao
Biological metal ions play crucial roles in various life processes and exhibit diverse biological functions. Specifically, Ca(II), Mg(II), Cu(II), and Mn (II) ions are intricately involved in insulin function. To further clarify the biological functions of biological metal ions on insulin, the interaction mechanism of insulin affected by Ca(II), Mg(II), Cu(II), and Mn (II) ions were comparably investigated via spectroscopic, circular dichroism(CD), and electrochemical approaches. Electrochemical studies demonstrate that Mn(II) forms an M 2 L-type complex with insulin, exhibiting a binding constant of β Mn = 9.3 × 10 9 , while Cu(II) and insulin form an M 4 L-type complex with a significantly higher binding constant of β Cu =9.18 × 10 12 . Electrochemical investigation of the interaction between Ca(II) and Mg(II) with insulin adsorbed onto a glass carbon electrode surface revealed that the presence of Ca(II) and Mg(II) induced conformational changes in insulin, resulting in reduced adsorption capacity. Additionally, it was observed that the presence of Ca(II) and Mg(II) enhanced the redox signal of probe ions. The binding constants values were calculated to be 1.108 × 10 3 L•mol –1 for the insulin-Ca(II) system and 2.28 ×10 2 L• mol –1 for the insulin-Mg(II) system. Spectroscopic studies showed that the binding of Cu(II) ions to insulin molecules may be controlled by chelation mechanism, and the interaction between Cu(II) ions and insulin molecules may occur in the aromatic region. Mn(II) ion binding is mainly controlled by ionic interactions, and its binding site is far away from the aromatic region.The combination of Ca(II) and Mg(II) with insulin induced a small enhancement in the Ultraviolet-visible (UV) absorption peak, with Ca(II) exhibiting a more pronounced effect compared to Mg(II). The results of spectral, CD and electrochemical studies are consistent.
研究领域:
生物化学
·
电化学
·
分子生物学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Jingsi Zhang,Xin Chen,Qiping Zhan,Yifan Wang,Keke Meng,Qiuhui Hu,Liyan Zhao
Flammulina velutipes ( F. velutipes ) polysaccharides have been shown to play a crucial role in preventing inflammatory diseases. However, further exploration is needed to understand the specific relationship between their structure and anti-inflammatory activity. In this study, four structurally distinct F. velutipes polysaccharides (FVP2, FVP2U1, FVP2U2, and FVP2U3) were isolated via a previously established ultrasonic degradation model, and the exploration on the impact of chain conformation on their anti-inflammatory activities was focused. The results indicated that FVP2 exhibited a spherical conformation, while FVP2U1 and FVP2U2 displayed flexible chains, and FVP2U3 showed a semi-rigid chain. The study on the impact of four kinds of F. velutipes polysaccharides on inflammatory response in LPS-stimulated RAW264.7 cells revealed that ultrasonic degradation enhanced the anti-inflammatory activity of FVP2. The primary anti-inflammatory mechanism involved the inhibition of NO, TNF-α, IL-1β, and IL-6 release, and reduced transcriptional levels of TLR4, MyD88, NF-κB, and NLRP3. Among the ultrasonically degraded polysaccharides with compliant chain conformations and lower molecular weight demonstrated superior anti-inflammatory activity. These results provide insights into the relationship between molecular weight, chain conformation, and anti-inflammatory activity of F. velutipes polysaccharides, contributing to the potential application of ultrasound in developing highly active anti-inflammatory polysaccharides and related nutritional products.
研究领域:
生物化学
·
免疫学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）