Structural changes

结构变化
  • 文章类型: Journal Article
    嗅觉功能障碍是帕金森病(PD)的常见非运动症状,可能对该疾病的潜在病理生理学具有宝贵的见解。本研究旨在使用基于表面的形态计量学(SBM)方法研究患有严重低检症(PD-SH)和轻度低检症(PD-MH)的PD患者的皮质形态计量学改变。参与者包括36例PD-SH患者,38例PD-MH患者,和40个健康对照(HCs)。SBM分析显示PD-SH和PD-MH患者皮质改变的不同模式。PD-MH患者表现出右缘上回皮质厚度减少,而PD-SH患者表现出广泛的皮质变薄的区域,包括双侧果皮皮质,双侧舌回,左下顶叶皮质,左枕骨外侧皮质,右侧三角部,右阴阳,和右上顶叶皮层.此外,与PD-MH患者相比,PD-SH患者的右前叶皮质厚度降低。分形维数分析显示PD-MH患者右颞上皮质和右上脑回的皮质复杂性增加,以及双侧中央后皮层的复杂性降低,左顶叶上皮质,和右中央前皮质。同样,与HC相比,PD-SH和PD-MH患者的皮质旋化指数和皮质沟深度表现出不同的变化模式。这些发现强调了PD中嗅觉障碍的多面性,皮质形态学改变的不同模式与不同程度的失足有关。观察到的大脑区域差异显示出改变,反映了PD病理生理学的复杂性。这些见解有助于更深入地了解PD的嗅觉功能障碍,并为早期诊断和有针对性的干预措施提供了潜在的途径。
    Olfactory dysfunction is a common non-motor symptom of Parkinson\'s disease(PD) and may hold valuable insights into the disease\'s underlying pathophysiology. This study aimed to investigate cortical morphometry alterations in PD patients with severe hyposmia(PD-SH) and mild hyposmia(PD-MH) using surface-based morphometry(SBM) methods. Participants included 36 PD-SH patients, 38 PD-MH patients, and 40 healthy controls(HCs). SBM analysis revealed distinct patterns of cortical alterations in PD-SH and PD-MH patients. PD-MH patients exhibited reduced cortical thickness in the right supramarginal gyrus, while PD-SH patients showed widespread cortical thinning in regions including the bilateral pericalcarine cortex, bilateral lingual gyrus, left inferior parietal cortex, left lateral occipital cortex, right pars triangularis, right cuneus, and right superior parietal cortex. Moreover, PD-SH patients displayed reduced cortical thickness in the right precuneus compared to PD-MH patients. Fractal dimension analysis indicated increased cortical complexity in PD-MH patients\' right superior temporal cortex and right supramarginal gyrus, as well as decreased complexity in the bilateral postcentral cortex, left superior parietal cortex, and right precentral cortex. Similarly, cortical gyrification index and cortical sulcal depth exhibited heterogeneous patterns of changes in PD-SH and PD-MH patients compared to HCs. These findings underscore the multifaceted nature of olfactory impairment in PD, with distinct patterns of cortical morphometry alterations associated with different degrees of hyposmia. The observed discrepancies in brain regions showing alterations reflect the complexity of PD\'s pathophysiology. These insights contribute to a deeper understanding of olfactory dysfunction in PD and provide potential avenues for early diagnosis and targeted interventions.
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  • 文章类型: Journal Article
    脂肪会极大地影响五花肉的整体质地和风味。两次煮熟的猪肚(TPB),通常在“回锅”被炒之前煮沸并切片,是炒菜中的经典川菜。在这项研究中,用过热蒸汽(SHS)技术代替传统的平底锅油炸(PCV)对感官的影响,纹理,研究了脂肪层的微观结构和风味。SHS用作沸腾的替代品(120°C持续15、20、25和30分钟),“回锅”也是SHS的炒菜。用SHS预煮25分钟的TPB(P25)的质量特性优于PCV,胶原纤维破坏和脂滴面积较少,导致较低的硬度和较高的剪切力。此外,SHS的低氧环境阻碍了脂质过氧化,MDA含量显著低于PCV。不同的是,PCV表现出更多的草味和脂肪味,而P25由于其在预烹饪阶段较高的UFA/SFA比率而表现出独特的果味和奶油香气。总的来说,P25的感官评分与PCV相当(无显著差异),揭示了SHS有望应用于炒菜的工业生产。
    Fat greatly impacts the overall texture and flavor of pork belly. Twice-cooked pork bellies (TPB), typically boiled and sliced before \"back to pot\" being stir-fried, is a classic Sichuan cuisine among stir-fried dishes. In this study, the effects of substituting conventional pan-frying (PCV) with superheated steam (SHS) technology on the sensory, texture, microstructure and flavor of the fat layers were investigated. SHS was used as an alternative to boiling (120 °C for 15, 20, 25, and 30 min), and \"back to pot\" stir-frying was also by SHS. TPB precooked for 25 min (P25) with SHS performed better quality characteristics than PCV, with less collagen fiber disruption and lipid droplet area, resulting in a lower hardness and higher shear force. Besides, the low-oxygen environment of SHS retarded the lipid peroxidation, showing a significantly lower MDA content than PCV. Differently, PCV exhibited more grassy and fatty flavors, while P25 exhibited a unique aroma of fruity and creamy due to its higher UFA/SFA ratios in the pre-cooking stage. Overall, the sensory scores of P25 were comparable to those of PCV (with no significant difference), revealing that SHS is expected to be applied to the industrial production of stir-fried dishes.
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  • 文章类型: Journal Article
    研究芝麻焙烧过程中木质素降解的机理,研究了在190-250°C下烘烤30分钟的芝麻籽壳样品中磨碎的木材木质素(MWL)的结构转化。调查结果显示,随着温度的升高,木质素碳水化合物复合物中碳水化合物的降解程度加深,这降低了总糖含量(从8.59%降低到0.45%)。与原始芝麻壳木质素(LSSH)相比,随着焙烧温度的升高(210-250°C),MWL级分的分子量显示出下降的趋势(Mw4377-2235Da)。在烘烤过程中,芝麻壳中的木质素经历了降解和冷凝。由于去甲氧基化,H型木质素比例从2.7%提高到26.1%。与G型和C型木质素相比,S型木质素更稳定。由于CO键断裂,β-O-4键从5.8降低到1.2/100Ar,从26.3到9.6/100Ar的β-β键由于CC的缩合而降低。随着焙烧温度的升高,木质素结构单元之间更多的化学键断裂,产生更多的酚羟基(1.80-2.03mmol/g)。这项研究有助于阐明烘烤过程中木质素降解对芝麻油氧化稳定性的贡献。
    To investigate the mechanism of lignin degradation during sesame roasting, structural transformations of milled wood lignin (MWL) from sesame seed hull samples roasted at 190-250 °C for 30 min were investigated. The findings revealed that, with increasing temperature, the degradation extent of carbohydrates from lignin carbohydrate complex in the fractions deepened, which reduced total sugar content (from 8.59 % to 0.45 %). Compared to that of the original sesame seed hull lignin (LSSH), the molecular weight of MWL fractions showed a tendency to decline (Mw 4377-2235 Da) with the rise of roasting temperature (210-250 °C). During roasting, lignins in the sesame seed hull underwent degradation and condensation. Due to demethoxylation, the H-type lignin proportion increased from 2.7 % to 26.1 %. Compared to G- and C-type lignin, S-type lignin was more stable. The β-O-4 linkages decreased from 5.8 to 1.2/100 Ar due to CO bond breaking, and β-β linkages from 26.3 to 9.6/100 Ar decreased due to condensation of CC. As the roasting temperature increased, more chemical bonds between lignin structural units were broken, resulting in the generation of more phenolic hydroxyl groups (1.80-2.53 mmol/g). This study helps to elucidate the contribution of lignin degradation during roasting to the oxidative stability of sesame oil.
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  • 文章类型: Journal Article
    β-乳球蛋白(BLG)的结合能力对于递送多酚至关重要,结构变化的影响。高压处理(HPP)有可能改变BLG的结构和聚集,但其对BLG-多酚相互作用的具体影响尚不确定。这项研究使用圆二色光谱和分子动力学模拟来揭示HPP引起的BLG结构变化,由指示聚集的粒度分析支持。七种结构多样的多酚(槲皮素-QR,Hesperetin-HSP,二氢杨梅素-DHM,没食子酸-GA,(-)-表儿茶素-EC,白藜芦醇-RES,和secoisolariciresinol二糖苷-SDG)进行了研究,以使用荧光光谱和分子对接全面分析其结合模式。HPP减少了BLG的有序结构,增加了其聚集。DHM的结合亲和力峰值为400MPa,QR,HSP,GA,和RES,而SDG和EC在大气压和600MPa下表现出最大亲和力,分别。升高的压力增强了BLG-多酚相互作用,特别是在44GLU和160CYS残基处,范德华力支配着束缚自由能。
    The binding capacity of β-Lactoglobulin (BLG) is crucial for delivering polyphenols, influenced by structural changes. High pressure processing (HPP) has the potential to modify BLG\'s structure and aggregation, but its specific impact on BLG-polyphenol interactions is uncertain. This study used circular dichroism spectroscopy and molecular dynamics simulations to reveal HPP-induced structural changes in BLG, supported by particle size analysis indicating aggregation. Seven structurally diverse polyphenols (quercetin-QR, hesperetin-HSP, dihydromyricetin-DHM, gallic acid-GA, (-)-epicatechin-EC, resveratrol-RES, and secoisolariciresinol diglucoside-SDG) were investigated to comprehensively analyze their binding patterns using fluorescence spectroscopy and molecular docking. HPP reduced BLG\'s ordered structure and increased its aggregation. Binding affinities peaked at 400 MPa for DHM, QR, HSP, GA, and RES, while SDG and EC exhibited maximum affinities at atmospheric pressure and 600 MPa, respectively. Elevated pressures enhanced BLG-polyphenol interactions, particularly at residues 44GLU and 160CYS, with van der Waals forces dominating the binding free energy.
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  • 文章类型: Journal Article
    探讨不溶性纤维的形态变化及其对微生物群调节的影响。特别是拟杆菌,在不同的饲料水分水平(E20、E40和E60)下挤出米糠不溶性纤维。理化性质和SEM显示E20表现出最高的持水能力,并显示出最破碎的边缘。E40具有最高的溶胀保持能力,并显示出最大的层状间隙。E60显示出物理化学性质的最小变化,但具有粗糙的表面。发酵48h后,E40显示出最高水平的拟杆菌和SCFA。E20和E60导致拟杆菌丰度的适度增加。SEM显示细菌附着在破碎的边缘,松散的层状间隙,和挤出的不溶性纤维的粗糙表面。结果表明,拟杆菌在挤出处理中获得了竞争优势,从而产生了结构变化。挤压处理可用于产生有利于拟杆菌的特定生态位。
    To investigate the morphological changes of insoluble fiber and their effects on microbiota modulation, particularly Bacteroides, rice bran insoluble fibers were extruded at different feed moisture levels (E20, E40, and E60). The physicochemical properties and SEM revealed that E20 exhibited the highest water holding capacity and displayed the most fragmented edges. E40 had the highest swelling holding capacity and displayed the most lamellar gaps. E60 showed minimal change in physicochemical properties but had a rough surface. After 48h fermentation, E40 showed the highest levels of Bacteroides and SCFAs. E20 and E60 resulted in a modest increase in Bacteroides abundance. SEM showed that bacteria were attached to fragmented edges, loosened lamellar gaps, and rough surfaces of the extruded insoluble fibers. The results suggested that Bacteroides gained a competitive advantage within the extrusion treatment created structural changes. Extrusion treatment can be used to generate specific niches favorable for Bacteroides.
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  • 文章类型: Journal Article
    在本研究中,我们研究了与乳清蛋白浓缩物80(WPC80)和L-抗坏血酸6-棕榈酸酯(LAP)对叶酸(FA)的稳定作用相关的机制。多光谱技术表明,WPC80主要通过疏水相互作用与FA和LAP结合,能量以非辐射形式(FA/LAP)从WPC80转移到FA和LAP;FA/LAP的组合导致WPC80的构象和二级结构含量发生变化,系统的绝对zeta电位增加,以及粒度分布向较小尺寸的偏移。该复合体系表现出增强的抗氧化性能和良好的粘合性能。此外,WPC80提高了FA在不同条件下的储存稳定性。这些结果表明,FA与WPC80和LAP共结合形成的三元复合物是提高FA稳定性的有效途径。
    In the present study, we investigated the mechanisms associated with the stabilizing effects of whey protein concentrate-80 (WPC80) and L-ascorbyl 6-palmitate (LAP) on folic acid (FA). Multispectral techniques show that WPC80 binds to FA and LAP mainly through hydrophobic interactions, and that energy is transferred from WPC80 to FA and LAP in a nonradiative form (FA/LAP); The combination of FA/LAP resulted in a change in the conformation and secondary structure content of WPC80, an increase in the absolute zeta potential of the system, and a shift in the particle size distribution towards smaller sizes. The compound system exhibits strengthened antioxidant properties and favorable binding properties. Besides, WPC80 improves the storage stability of FA under different conditions. These results demonstrated that the ternary complex formed by FA co-binding with WPC80 and LAP is an effective way to improve the stability against of FA.
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  • 文章类型: Journal Article
    这项研究调查了辛烯基琥珀酸酐(OSA)-淀粉-脂肪酸(FA)相互作用对结构的影响,高直链淀粉玉米淀粉(HAS)的消化率和释放特性。FTIR和XRD分析表明,HAS和FA之间的疏水相互作用促进了OSA和HAS之间的共价结合。随着FA链长度的增加,复杂指数,替代程度,R1047/1022和OSA-HAS-FA的相对结晶度先升高后降低,而在无限时间内,一阶速率系数和消化百分比表现出相反的趋势。OSA-HAS-FA与12碳FA的结构变化和分子相互作用导致最高的抗性淀粉含量(45.43%)和姜黄素(Cur)的包封率(47.98%)。体外释放试验表明,Cur可以在模拟胃中从OSA-HAS-FA中逐渐释放,肠液和结肠液。结果为OSA接枝的HAS-FA复合物作为结肠特异性功能材料的载体提供了新的见解。
    This study investigated the effects of octenyl succinic anhydride (OSA)-starch-fatty acid (FA) interactions on the structural, digestibility and release characteristics of high amylose corn starch (HAS). FTIR and XRD analysis showed that the hydrophobic interaction between HAS and FA promoted the covalent binding between OSA and HAS. With the increasing of the FA chain length, the complex index, degree of substitution, R1047/1022 and relative crystallinity of OSA-HAS-FA increased first and then decreased, whereas the first-order rate coefficient and percentage of digested in infinite time showed an opposite trend. Structural changes and the molecular interactions of OSA-HAS-FA with 12‑carbon FA resulted in highest resistant starch content (45.43%) and encapsulation efficiency of curcumin (Cur) (47.98%). In vitro release test revealed that Cur could be gradually released from OSA-HAS-FA in simulated gastric, intestinal and colonic fluids. Results provided novel insights into HAS-FA complex grafted with OSA as carrier for colon-specific of functional materials.
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  • 文章类型: Journal Article
    这项工作研究了海藻糖(TH)和焦磷酸钠(SPP)单独和联合使用对90天冷冻储存(-20°C)期间silver鱼糜肌原纤维蛋白(MP)氧化和结构变化的冷冻保护作用。TH联合SPP在预防MP氧化方面明显优于单一TH或SPP(P<0.05),显示较高的SH含量(6.05nmol/mg蛋白质),和较低的羰基(4.24nmol/mg蛋白质)和二酪氨酸含量(1280A.U.)。SDS-PAGE结果表明,TH与SPP组合在抑制蛋白质降解方面与TH和SPP没有显着差异,但在抑制蛋白质交联方面更有效。此外,所有冷冻保护剂都可以稳定二级和三级结构,并抑制MP的展开和聚集,TH和SPP的组合是最好的。值得指出的是,TH与SPP联用对抑制α-螺旋含量的降低和凝胶形成能力具有协同作用,和表面疏水性的增加。总的来说,TH与SPP联用能显著抑制鱼糜在冷冻保存过程中的MP氧化和结构变化,提高其凝胶形成能力。显著优于单一TH或SPP。
    This work investigated the cryoprotective effect of trehalose (TH) and sodium pyrophosphate (SPP) alone and in combination on myofibrillar protein (MP) oxidation and structural changes in silver carp surimi during 90 days of frozen storage (-20 °C). TH combined with SPP was significantly more effective than single TH or SPP in preventing MP oxidation (P < 0.05), showing a higher SH content (6.05 nmol/mg protein), and a lower carbonyl (4.24 nmol/mg protein) and dityrosine content (1280 A.U.). SDS-PAGE results indicated that TH combined with SPP did not differ significantly from TH and SPP in inhibiting protein degradation but was more effective in inhibiting protein crosslinking. Moreover, all cryoprotectants could stabilise the secondary and tertiary structures and inhibit unfolded and aggregation of MP, with the combination of TH and SPP being the best. It\'s worth noting that TH combined with SPP had a synergistic effect on inhibiting the decrease in α-helix content and gel-forming ability, and the increase in surface hydrophobicity. Overall, TH combined with SPP could significantly inhibited MP oxidation and structural changes in surimi during frozen storage and improve the gel-forming ability, which was significantly better than single TH or SPP.
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  • 文章类型: Journal Article
    掺杂在调节和增强有机半导体(OSC)器件的性能中起着至关重要的作用。在这项研究中,强调了掺杂剂在塑造OSC膜的形态和结构中的关键作用,这反过来又深刻地影响了它们的属性。两种掺杂剂,三苯甲基四(五氟苯基)(TrTPFB)和N,四(五氟苯基)硼酸N-二甲基苯胺(DMA-TPFB),检查了它们对聚(3-己基噻吩)(P3HT)和PBBT-2T宿主OSC的掺杂作用。发现尽管TrTPFB表现出更高的掺杂效率,掺杂有DMA-TPFB的OSC实现相当的或甚至增强的电导率。的确,掺杂DMA-TPFB的P3HT的电导率达到67Scm-1以上,这是混合溶液掺杂的P3HT的创纪录值。这可以归因于DMA-TPFB诱导更高程度的结晶度和减少的结构无序。此外,DMA-TPFB对OSC膜形态和结构的有益影响导致掺杂OSC的优异的热电性能。这些发现强调了掺杂剂诱导的形态和结构考虑在增强OSC的膜特性方面的重要性。为优化掺杂剂性能开辟了一条新途径。
    Doping plays a crucial role in modulating and enhancing the performance of organic semiconductor (OSC) devices. In this study, the critical role of dopants is underscored in shaping the morphology and structure of OSC films, which in turn profoundly influences their properties. Two dopants, trityl tetrakis(pentafluorophenyl) (TrTPFB) and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate (DMA-TPFB), are examined for their doping effects on poly(3-hexylthiophene) (P3HT) and PBBT-2T host OSCs. It is found that although TrTPFB exhibits higher doping efficiency, OSCs doped with DMA-TPFB achieve comparable or even enhanced electrical conductivity. Indeed, the electrical conductivity of DMA-TPFB-doped P3HT reaches over 67 S cm-1, which is a record-high value for mixed-solution-doped P3HT. This can be attributed to DMA-TPFB inducing a higher degree of crystallinity and reduced structural disorder. Moreover, the beneficial impact of DMA-TPFB on the OSC films\' morphology and structure results in superior thermoelectric performance in the doped OSCs. These findings highlight the significance of dopant-induced morphological and structural considerations in enhancing the film characteristics of OSCs, opening up a new avenue for optimization of dopant performance.
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  • 文章类型: Journal Article
    大量使用塑料包装会导致严重的环境污染。在这项研究中,市售塑料包装的表面结构和微生物群落演变[聚乙烯(PE),聚氯乙烯(PVC),聚偏二氯乙烯(PVDC),和聚乳酸(PLA)]在人工湿地(CWs)中进行了研究。结果表明,所有塑料包装的分子量逐渐降低,结晶度熔化,和结晶温度,而表面粗糙度逐渐增加,聚合物分散指数(PDI),微生物定殖CW的羰基指数(CI)和Shannon指数。保鲜膜的老化率依次为:PLA>PVC>PE>PVDC,在CW的同一地点,顺序是:土壤表面>植物根>底土,同样的塑料包装。同一保鲜膜定殖的微生物多样性依次为:植物根>底土>土壤表面。塑料包装上的微生物的香农指数低于土壤中的微生物,表明微生物定植塑料包装的多样性是有限的。此外,塑料表面的微生物群落结构被塑料类型共分化,CW中的放置位置,和老化时间。在PVC和PVDC包裹物表面上发现了明显不同的微生物群落结构,揭示了塑料中的氯限制了微生物的多样性。根瘤菌科和假单胞菌科的未分类成员是塑料包装表面的优势属,这表明它们可能是参与塑料降解过程的微生物。该研究提供了宝贵的观点,以促进对移民的全面了解,命运,以及与湿地微塑料(MPs)相关的环境风险。
    The high use of plastic wraps leads to significant environmental pollution. In this study, the surface structure and microbial community evolution of commercially available plastic wraps [polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and polylactic acid (PLA)] in constructed wetlands (CWs) were investigated. The results indicated that all plastic wraps gradually decreased in molecular weight, crystallinity, melting, and crystallization temperatures, whereas a gradual increase was observed in the surface roughness, polymer dispersity index (PDI), carbonyl index (CI) and Shannon index of microorganisms colonizing the CWs. The aging rate of the plastic wrap was in the order: PLA > PVC > PE > PVDC, at the same site in the CWs, and it was in the order: soil surface > plant roots > subsoil, for the same plastic wrap. The diversity of microorganisms colonizing the same plastic wrap was in the order: plant roots > subsoil > soil surface. The Shannon indices of microorganisms on plastic wraps were lower than those in the soil, indicating that the diversity of microorganisms colonizing plastic wraps is limited. Additionally, the microbial community structure on the plastic surface was co-differentiated by the plastic type, placement position in the CWs, and aging time. Significantly different microbial community structures were found on the PVC and PVDC wrap surfaces, revealing that the chlorine in plastics limits microbial diversity. Unclassified members of Rhizobiaceae and Pseudomonadaceae were the dominant genera on the surface of the plastic wraps, suggesting that they may be the microorganisms involved in plastic degradation processes. The study provides valuable perspectives to facilitate a comprehensive understanding of the migration, fate, and environmental risks associated with microplastics (MPs) in wetlands.
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