Effects of ultra-high-pressure treatment on the structural and functional properties of buckwheat 13S globulin

Components with strong adsorption capacity for cholates from buckwheat proteins were screened, separated and purified by several methods, and the effects of ultra-high-pressure(UHP) on the structure and function of buckwheat 13S globulin(BW13SG) were studied. Samples were treated by UHP at different p H(3.0 and 7.0) value(s) and at 100–500 MPa for 10–30 min. The results showed that the tertiary structure of BW13SG was partially denatured and aggregated. The decrease in the unordered structure indicated that UHP resulted in a looser secondary structure of BW13SG. UHP treatment also increased solubility, emulsion activity and stability, foaming capacity and stability. The samples treated at 500 MPa, p H 3.0 for 30 min had the most enhanced functionality. Moreover, under this condition, the sodium cholate and sodium deoxycholate adsorption capacities of BW13SG were both higher than 98% and the adsorption capacity of sodium taurocholate, which can be difficult to adsorb, was higher than 60%.

Selective logging enhances ecosystem multifunctionality via increase of functional diversity in a Pinus yunnanensis forest in Southwest China

Background:The impacts of selective logging on ecosystem multifunctionality(EMF)remain largely unexplored.In this study,we analyzed the response of nine variables related to four ecosystem functions(i.e.nutrient cycling,soil carbon stocks,decomposition,and wood production)to five selective logging intensities in a Pinus yunnanensisdominated forest.We included a control group with no harvest to evaluate the potential shifts in EMF of the P.yunnanensis forests.We also assessed the relationship between above-and belowground biodiversity and EMF under these different selective logging intensities.Additionally,we evaluated the effects of biotic and abiotic factors on EMF using a structural equation modeling(SEM)approach.Results:Individual ecosystem functions(EFs)all had a significant positive correlation with selective logging intensity.Different EFs showed different patterns with the increase of selective logging intensity.We found that EMF tended to increase with logging intensity,and that EMF significantly improved when the stand was harvested at least twice.Both functional diversity and soil moisture had a significant positive correlation with EMF,but soil fungal operational taxonomic units(OTUs)had a significant negative correlation with EMF.Based on SEM,we found that selective logging improved EMF mainly by increasing functional diversity.Conclusion:Our study demonstrates that selective logging is a good management technique from an EMF perspective,and thus provide us with potential guidelines to improve forest management in P.yunnanensis forests in this region.The functional diversity is maximized through reasonable selective logging measures,so as to enhance EMF.

Tree structure and diversity shape the biomass of primary temperate mountain forests

Primary forests are spatially diverse terrestrial ecosystems with unique characteristics,being naturally regenerative and heterogeneous,which supports the stability of their carbon storage through the accumulation of live and dead biomass.Yet,little is known about the interactions between biomass stocks,tree genus diversity and structure across a temperate montane primary forest.Here,we investigated the relationship between tree structure(variability in basal area and tree size),genus-level diversity(abundance,tree diversity)and biomass stocks in temperate primary mountain forests across Central and Eastern Europe.We used inventory data from726 permanent sample plots from mixed beech and spruce across the Carpathian Mountains.We used nonlinear regression to analyse the spatial variability in forest biomass,structure,and genus-level diversity and how they interact with plot-level tree age,disturbances,temperature and altitude.We found that the combined effects of genus and structural indices were important for addressing the variability in biomass across different spatial scales.Local processes in disturbance regimes and uneven tree age support forest hete rogeneity and the accumulation of live and dead biomass through the natural regeneration,growth and decay of the forest ecosystem.Structural complexities in basal area index,supporte d by genus-level abundance,positively influence total biomass stocks,which was modulated by tree age and disturbances.Spruce forests showed higher tree density and basal area than mixed beech forests,though mixed beech still contributes significantly to biomass across landscapes.Forest heterogeneity was strongly influenced by complexities in forest composition(tree genus diversity,structure).We addressed the importance of primary forests as stable carbon stores,achieved through structure and diversity.Safeguarding such ecosystems is critical for ensuring the stability of the primary forest,carbon store and biodiversity into the future.

Functions, Problems and Countermeasures of China’s Rural Ecosystems

At present,the whole country is fully implementing rural revitalization strategy and actively promoting rural ecosystems development in China.From the perspective of ecology and agroecology,the main functions of rural ecosystem in China,the current outstanding problems,and the corresponding countermeasures and measures are discussed in the paper,in order to provide references for promoting the implementation of the strategy of rural revitalization and the sustainable development of rural ecosystem.China’s rural ecosystem has multi-functions such as carrying population,improving environment,providing products,increasing income,expanding employment and tourism,inheriting culture,popularizing science and technology,educating people,training talents,and providing places for the aged urban residents.Currently,there are still many problems and challenges in rural ecosystem in China,such as ecological destruction,waste of resources,environmental pollution,natural disasters,economic poverty,backward science and education,laggard culture and medical care,lack of public services,bad social morality,loss of villagers and disappearance of villages.In order to promote implementation of rural revitalization strategy and to promote sustainable development of rural ecosystems in China,the following measures should be taken based on the principles of integrating “tri-benefits”(economic,ecological and social benefits),gradual progress,comprehensive governance,adaptation to local conditions and long-term efforts and success.Eventually,the following measures are suggested:① enhancing awareness;② planning well;③ improving environment;④ optimizing ecological structure;⑤ improving ecological functions;⑥ improving ecological conditions;⑦ strengthening public services;⑧ improving laws and regulations;⑨ improving great investment;⑩ accelerating personnel training.

Study on Plant Community Characteristics and Ecological Functions of Mingyue Park in Jingzhou City

[Objectives]This study was conducted to analyze species composition, community appearance, plant life-type spectrum, flora distribution, plant community structure and plant diversity indexes of Mingyue Park in Jingzhou City, as well as the ecological functions of plants in cooling, humidification, shading, and noise reduction. [Methods] A quadart method was used to investigate plant communitues of Mingyue Park in Jingzhou City. [Results] There were 141 species in the park, including 44 tree speceies, 35 shrub speceies, and 62 herb speceies. The arber-shrub-grass structure was the dominant plant community structure. The Simpson index(D), Shannon-Wiener index(H) and Pielou index(J) of the herb layer were higher than those of the tree layer and the shrub layer, and the shrub layer was the lowest. The results of ecological function research showed that the plant communities had a significant shading effect and a certain ability to reduce noise. The comprehensive conclusion showed that the ecological function indexes of the arbor-shrub-grass structure in Mingyue Park were significantly higher than those of the arbor-shrub structure and the single-tree structure. In order to improve the ecological benefits of plant communities in Mingyue Park, the plant diversity can be increased in the later construction to enrich community structures. [Conclusions] This study evaluated the ecological benefits of plant communities in Mingyue Park, and provides a scientific basis for the plant configuration of parks in Jingzhou and other regions.

The Characteristics and Pragmatic Strategies of English Euphemism

Some words may cause embarrassment in daily communication,and euphemism is a language type to avoid embarrassment.Euphemism is widely used in English expression.On the basis of exploring the characteristics of English euphemism in times,regionalism,register,and nationality,this paper discusses in detail the pragmatic functions of English euphemism from four dimensions,namely taboo,politeness,positivity,and concealment,in order to provide guidance for the proper use of English euphemism.

Pectin fractions extracted sequentially from Cerasus humilis:Their compositions,structures,functional properties and antioxidant activities

Three pectin fractions(water-soluble fraction(WSF),chelator-soluble fraction(CSF),and sodium carbonatesoluble fraction(NSF))were obtained from Chinese dwarf cherry(Cerasus humilis)fruits.All of them were branched low methoxylated pectins with an amorphous or partially nanocrystalline nature and eight neutral monosaccharides(arabinose and galactose were most abundant).WSF,CSF and NSF had a degree of methylation(DM)of 35.82%,14.85%and 7.13%,uronic acid(UA)content of 76.02%,83.71%and 69.01%,and total protein content of 2.4%,2.1%and 8.8%,respectively.Their molecular weights were 340.31,330.16 and 141.31 kg/mol,respectively(analyzed by gel permeation chromatography(GPC)).WSF,CSF and NSF exhibited good rheological,thermal,emulsifying,emulsion-stabilizing,water-adsorbing,oil-binding,cholesterol-binding and antioxidant properties.NSF had the highest emulsifying,emulsion stabilizing,water-/oil-/cholesterol-binding and antioxidant capacities,followed by CSF.NSF had the highest viscosity(406.77 m Pa·s),flowability,and resistance to heat-induced changes/damage,which may be related to its lowest polydispersity index,DM and UA content and highest protein content.The three pectin fractions with desirable characteristics can be used as food additives/ingredients and dietary supplements.

Characteristic Functional Structure of Infinitesimal Symmetry Transformations for Nonholonomic System

It was proved that velocity-dependent infinitesima l symmetry transformations of nonholonomic systems have a characteristic functio nal structure, which could be formulated by means of an auxiliary symmetry tra nsformation function and is manifestly dependent upon constants of motion of th e system. An example was given to illustrate the applicability of the results.

The New Understanding of Yin and Yang of TCM Physiological Model

From the view of the physical model,structure and function characteristics,the material basis and clinical application of Yin-Yang theory,analysing and thinking combined with modern medical theory,this paper finds that as one of the most basic and important theory of traditional Chinese medicine(TCM),Yin-Yang theory reveals the understanding of human physiology in TCM,which has many consensuses with modern medicine,so it is worth studying further.

Matrix description of differential relations of moment functions in structural reliability sensitivity analysis

In a structural system reliability analysis that lacks probabilistic information, calculating the numerical characteristics of the state functions, especially the first four moments of the state functions, is necessary. Based on that, the structural system reliability is analyzed with a fourth-order moment method. The reliability sensitivity is required to conduct the differential operation of the numerical characteristic functions. A reliability sensitivity analysis formula is then derived in combination with the relation of the differential operation. Based on the matrix theory and Kronecker algebra, this paper systematically derives a matrix expression of the first four moments of the state functions, and establishes the matrix relation between the first four moments of the state functions and those of the basic random variables. On this basis, a differential operation formula of the first four moments of the state functions is further derived against the first four moments of the basic random variables. The vector relation between the state functions and the multidimensional basic random variables is described by means of the matrix operation to extend the operation method. Finally, a concise and intuitive formula is obtained to explore the inherent essential relation between the numerical characteristics of the state functions and those of the basic random variables, leading to a universal equation for the two kinds of numerical characteristics.

A Modified Model for Soil–Structure Interface Considering Random Damage of Mesoscopic Contact Elements

The interaction between soil and marine structures like submarine pipeline/pipe pile/suction caisson is a complicated geotechnical mechanism process.In this study,the interface is discretized into multiple mesoscopic contact elements that are damaged randomly throughout the shearing process due to the natural heterogeneity.The evolution equation of damage variable is developed based on the Weibull function,which is able to cover a rather wide range of distribution shapes by only two parameters,making it applicable for varying scenarios.Accordingly,a statistical damage model is established by incorporating Mohr–Coulomb strength criterion,in which the interfacial residual strength is considered whereby the strain softening behavior can be described.A concept of“semi-softening”characteristic point on shear stress–displacement curve is proposed for effectively modeling the evolution of strain softening.Finally,a series of ring shear tests of the interfaces between fine sea sand and smooth/rough steel surfaces are conducted.The predicted results using the proposed model are compared with experimental data of this study as well as some results from existing literature,indicating that the model has a good performance in modeling the progressive failure and strain softening behavior for various types of soil–structure interfaces.

Review of forest ecology studies in China

As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.

高压射流协同pH循环处理对大米-豌豆复合蛋白功能性及结构的影响

为探究复合植物蛋白经高压射流磨与p H循环共同处理后的增溶作用,明晰其增溶机制,采用大米蛋白与豌豆蛋白作为原料,配制蛋白比例1:1,总蛋白浓度4%的混合蛋白溶液,并将混合液p H调整至12,在高压射流磨不同压力下进行处理,再将溶液pH调回中性后得到复合蛋白。采用氮溶解指数、粒径、荧光光谱、圆二色谱、分子量等手段表征本工艺过程中复合蛋白理化性质和结构的变化。结果表明,经高压射流磨协同pH循环处理4%的复合蛋白,复合蛋白氮溶解指数随着压力增大而提升,处理压力为120MPa时,氮溶解指数为92.67%±0.77%。扫描电镜与粒径结果显示,射流磨处理后的复合蛋白尺寸降低,比表面积增大。内源荧光光谱、表面疏水性、巯基二硫键、圆二色谱结果显示,两种蛋白之间产生了相互作用,形成了新的共架体,且复合蛋白随处理压力增大,表面疏水性由4025.33显著增大至7359.45(P<0.05),疏水区域增加、游离巯基含量由26.46±0.32μmol/g显著上升至最高32.66±0.35μmol/g(P<0.05),二硫键含量由9.86±0.42μmol/g显著下降至5.48±0.27μmol/g(P<0.05),α-螺旋实际含量(25.3%)高于理论值(21.83%),二级结构向更亲水的α-螺旋转变。此外,氨基酸分析显示复合蛋白的氨基酸配比均衡完整。经处理后的复合蛋白在高溶解性的基础上,乳化与起泡性能均明显优于大米蛋白与豌豆蛋白。本研究表明高压射流磨协同pH循环的处理方法能够有效改善复合蛋白的功能特性,为植物蛋白工业化增溶改性提供理论支撑。

响应面优化氯化胆碱-丙三醇体系提取芝麻蛋白工艺条件

为提高芝麻油副产物芝麻饼粕中蛋白质的综合利用率,以芝麻粕为原料,选用氯化胆碱-丙三醇(物质的量比1∶3)体系(低共熔溶剂,DES)提取芝麻蛋白,通过单因素试验和响应面试验优化提取工艺条件,分析最优条件下提取的芝麻蛋白的功能特性,并采用傅里叶变换红外光谱和扫描电子显微镜对芝麻蛋白进行结构表征,同时与传统碱溶酸沉法提取工艺进行对比。结果表明:DES提取芝麻蛋白的最优条件为DES含水量10%、固液比1∶29.4、提取温度59.0℃、提取时间1 h、搅拌速度750 r/min,在此条件下芝麻蛋白提取率为(64.65±0.52)%,显著低于碱溶酸沉法芝麻蛋白的提取率[(74.19±1.79)%];DES提取的芝麻蛋白的溶解性、吸油性、泡沫稳定性和乳化稳定性均显著高于碱溶酸沉法提取的,而吸水性显著低于碱溶酸沉法提取的;DES提取的芝麻蛋白的β-折叠含量显著低于碱溶酸沉法提取的,而其他二级结构(α-螺旋、无规卷曲、β-转角、β-逆折叠)的含量则显著高于碱溶酸沉法提取的。综上,DES提取法可作为新型绿色的芝麻蛋白提取方法。

结构抗震可靠度分析的特征函数卷积方法

为提高极值分布尾部的计算精度,提出了一种结构抗震可靠度分析新方法,该方法通过特征函数卷积技术实现了精度的提升。首先,利用带权重的高斯混合分布来表征极值分布,并推导了极值分布特征函数的解析表达式;结合数值计算得到的特征函数曲线,运用卷积技术高效地确定了特征函数解析表达式中所有参数,包括权重系数、均值和标准差。将这些参数回代入极值分布表达式,即可获得极值分布及其累积分布函数,进而可方便地计算结构抗震可靠度。通过数值算例,验证了所提方法在重构极值分布中的有效性;进一步与Mellin变换和广义分布重构方法进行了对比,凸显了所提方法在极值分布尾部计算精度上的优势。

食品蛋白纤维的研究进展及功能应用

近年来,蛋白质纤维化因其赋予食品良好的功能特性和良好的稳定性而受到广泛关注。蛋白纤维在适当的外界条件下可以自组装形成,是一种具有广泛应用前景的食品原料。为了更全面地认识食品蛋白纤维,本文针对食品蛋白纤维的自组装、结构特征、来源以及功能特性等方面的研究进展进行了综述。重点介绍了蛋白质纤维的纤维化条件、自组装形成机理、蛋白纤维的功能特性(包括理化特性和生物活性)及其在食品领域的应用。最后,本文在现有研究基础上,创新性地提出了蛋白纤维的未来研究方向,旨在为其在食品工业的高质量应用提供参考。

改性技术对酵母蛋白功能特性与结构的影响研究进展

酵母因蛋白质含量丰富、富含人体必须的氨基酸且营养价值高,是天然优质的蛋白来源。但是,溶解性等功能特性限制了酵母蛋白在食品领域的广泛应用。本文从物理改性、化学改性、生物改性3个方面综述了改性技术对酵母蛋白功能特性与结构的影响,分析目前存在的问题并进行展望。本文旨在拓宽酵母蛋白的应用范围,填补因全球动物和植物蛋白人均需求量和年需求量增加导致的市场缺口,为保障全民健康提供支撑。

大豆蛋白改性技术及其联合应用的研究进展

大豆蛋白(SPs)作为一种重要的植物蛋白在食品、医药等领域具有广阔的应用前景。然而,复杂的结构导致其功能特性无法满足实际需求。随着现代加工技术的迅速发展,多种蛋白质改性技术被广泛研究。本文详细阐述了物理、化学、生物三类改性技术对SPs结构和功能特性的影响及蛋白质“结构修饰-功能改善”的机制,总结了多技术联合应用改善SPs结构和功能特性的研究现状。基于现有成果,展望未来提出应深入研究的方向,以期扩大SPs的应用市场,进一步促进大豆产业的发展。

Dof基因家族调节植物生长发育功能的研究进展

Dof(DNA binding with one finger)蛋白是一类植物特异性转录因子,通常含有200～400个氨基酸和2个主要结构域。该家族成员的N-末端为高度保守的单锌指Dof结构域,具有与DNA和蛋白质相互作用的双重功能,其C末端的氨基酸序列则较为多变,是Dof蛋白重要的特异转录调控结构域。研究表明,Dof蛋白作为转录激活物或阻遏物参与了多方面的植物生长发育过程。随着基因组测序技术的发展,已有大量的Dof基因从植物基因组数据库中鉴定出来。该文对近年来国内外有关Dof基因家族的结构特点、全基因组鉴定、蛋白互作以及生物学功能等方面的研究进展进行综述,以期为Dof转录因子的深入研究提供参考。

植物Dof基因结构特点及功能研究进展

DNA结合单锌指(DNA binding with one zinc finger,Dof)蛋白是由多基因共同编码的只在植物中存在的一类转录因子,其N-末端含有高度保守的由52个氨基酸残基组成的C2-C2型单锌指结构域,可以与DNA和蛋白质结合并相互作用;C-末端是特异转录调控结构域,因其序列具有多变性,导致Dof基因功能的多样性。随着基因组学和生物信息学的发展,近年来已有多个物种的Dof蛋白相继被报道出来。Dof基因主要参与植物的生长发育、碳氮代谢、非生物胁迫及开花调控等生物学过程。综述了植物Dof转录因子的结构特性、已经报道的Dof基因数目及生物学功能,在此基础上讨论了毛竹开花研究存在的问题,并提出未来的展望,以期为进一步研究Dof转录因子提供参考。