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
    全球经济和决策者当前的主要关注点之一是加密货币采矿和交易中的能源利用效率。随着相关碳排放的减少。了解比特币的能源消耗模式及其泡沫频率可以大大增强能源效率和碳减排的政策分析和决策。这项研究旨在评估比特币电力消耗和碳足迹随机游走假设的有效性。我们采用了传统方法(ADF和KPSS)和最近提出的单位根技术,这些技术考虑了数据系列中的结构断裂和非线性。我们的分析涵盖了2010年7月至2021年12月的每日数据。实证结果表明,传统的单位根技术并不能证实比特币电力消耗和碳足迹的平稳性。然而,进行的新颖的结构断裂(SB)和线性测试使我们能够发现2012年至2020年之间的五次SB事件以及变量的非线性,这为我们应用新开发的具有结构断裂的非线性单位根检验提供了信息。有了新的方法,结果表明,在适应SB和非线性后具有平稳性。此外,根据菲利普斯和史(2019)的检验,我们确定了2013年至2021年间比特币能源和碳变量的某些泡沫事件。比特币能源消耗和碳足迹泡沫的主要驱动因素是与比特币和金融市场活动和风险有关的变量。包括全球经济和政治风险。基于上述发现的研究结论为能源和环境管理提供了一些政策含义,包括鼓励加密货币采矿和交易的绿色投资。
    One of the main current focuses of global economies and decision-makers is the efficiency of energy utilization in cryptocurrency mining and trading, along with the reduction of associated carbon emissions. Understanding the pattern of Bitcoin\'s energy consumption and its bubble frequency can greatly enhance policy analysis and decision-making for energy efficiency and carbon emission reduction. This research aims to assess the validity of the random walk hypothesis for Bitcoin\'s electricity consumption and carbon footprint. We employed both traditional methods (ADF and KPSS) and recently proposed unit root techniques that account for structural breaks and non-linearity in the data series. Our analysis covers daily data from July 2010 to December 2021. The empirical results revealed that traditional unit root techniques did not confirm the stationarity of both bitcoin\'s electricity consumption and carbon footprint. However, novel structural break (SB) and linearity tests conducted enabled us to discover five SB episodes between 2012 and 2020 and non-linearity of the variables, which informed our application of the newly developed non-linear unit root tests with structural breaks. With the new methods, the results indicated stationarity after accommodating the SB and non-linearity. Furthermore, based on Phillips and Shi (2019)\'s test, we identified certain bubble episodes in the bitcoin energy and carbon variables between 2013 and 2021. The major drivers of the bubbles in bitcoin energy consumption and carbon footprint are variables relating to the bitcoin and financial markets activities and risks, including the global economic and political risks. The study\'s conclusion based on the above findings informs several policy implications drawn for energy and environmental management including the encouragement of green investments in cryptocurrency mining and trading.
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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
    历史上,风湿性疾病的成像是使用常规的X线照相术进行的。MRI为早期疾病中骨髓信号的改变提供了检测的机会,而在其他成像方式(如射线照相术)上是不可见的。计算机断层扫描,或超声检查。这篇综述描述了当前MRI技术在风湿病的诊断和治疗监测中的优势。此外,这篇综述讨论了在高场磁场强度下的新型MRI技术,该技术可能会在将来使用,以提高成像分辨率并对轴向和外周关节进行定量评估。
    Imaging of rheumatologic diseases has historically been performed using conventional radiography. MRI offers an opportunity for detection of altered marrow signal in early disease that is not visible on other imaging modalities such as radiography, computed tomography, or sonography. This review describes the advantages of current MRI techniques in the diagnosis and treatment monitoring of rheumatologic diseases. In addition, this review discusses novel MRI techniques at high-field magnetic strength which may be deployed in the future to allow for improved imaging resolution and quantitative assessment of both axial and peripheral joints.
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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
    微流化处理对初级,次要,研究了大豆分离蛋白(SPI)的三级结构。在控制和不控制温度的情况下处理样品,并在高压(137MPa)下在系统中循环1、3和5次。然后,将处理过的样品冷冻干燥并在水中重构,以检查微流化对两种不同状态的影响:粉末和溶液。关于一级结构,还原条件下的SDS-PAGE分析表明,当暴露于微流化处理时,蛋白质条带保持不变。当控制粉末状态的样品的温度时,注意到β-折叠和无规卷曲的数量显着减少,而α-螺旋含量略有减少。在处理过的样品中观察到的β-折叠的减少和β-转角的增加表明微流化可能导致蛋白质解折叠,打开疏水区域。此外,较低的α-螺旋表明较高的蛋白质灵活性。在水中复原后,仅在α-螺旋中观察到显著差异,β-折叠和β-转角。与三级结构相关,微流化增加了表面疏水性。在所有测试的条件中,控制温度的样品似乎最合适。
    The effect of microfluidization treatment on the primary, secondary, and tertiary structure of soybean protein isolate (SPI) was investigated. The samples were treated with and without controlling the temperature and circulated in the system 1, 3, and 5 times at high pressure (137 MPa). Then, the treated samples were freeze-dried and reconstituted in water to check the impact of the microfluidization on two different states: powder and solution. Regarding the primary structure, the SDS-PAGE analysis under reducing conditions showed that the protein bands remained unchanged when exposed to microfluidization treatment. When the temperature was controlled for the samples in their powder state, a significant decrease in the quantities of β-sheet and random coil and a slight reduction in α-helix content was noticed. The observed decrease in β-sheet and the increase in β-turns in treated samples indicated that microfluidization may lead to protein unfolding, opening the hydrophobic regions. Additionally, a lower amount of α-helix suggests a higher protein flexibility. After reconstitution in water, a significant difference was observed only in α-helix, β-sheet and β-turn. Related to the tertiary structure, microfluidization increases the surface hydrophobicity. Among all the conditions tested, the samples where the temperature is controlled seem the most suitable.
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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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