Dietary polyphenols reduced the allergenicity ofβ-lactoglobulin via non-covalent interactions:a study on the structure-allergenicity relationship

Studies showed that complexation of polyphenols with milk allergens reduced their immunogenic potential.However,the relationship between structures of polyphenols and their hypoallergenic effects on milk allergens in association with physiological and conformational changes of the complexes remain unclear.In this study,polyphenols from eight botanical sources were extracted to prepare non-covalent complexes withβ-lactoglobulin(β-LG),a major allergen in milk.The dominant phenolic compounds bound toβ-LG with a diminished allergenicity were identified to investigate their respective role on the structural and allergenic properties ofβ-LG.Extracts from Vaccinium fruits and black soybeans were found to have great inhibitory effects on the IgE-and IgG-binding abilities ofβ-LG.Among the fourteen structure-related phenolic compounds,flavonoids and tannins with larger MWs and multi-hydroxyl substituents,notably rutin,EGCG,and ellagitannins were more potent to elicit changes on the conformational structures ofβ-LG to decrease the allergenicity of complexedβ-LG.Correlation analysis further demonstrated that a destabilized secondary structure and protein depolymerization caused by polyphenol-binding were closely related to the allergenicity property of formed complexes.This study provides insights into the understanding of structure-allergenicity relationship ofβ-LG-polyphenol interactions and would benefit the development of polyphenol-fortified matrices with hypoallergenic potential.

Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

γ-Secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface receptors.Mutations inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-Secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as well.However,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-secretase.In this review,we focus on recent studies of structural dynamic mechanisms ofγ-secretase.Different mechanisms,including the“Fit-Stay-Trim,”“Sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics simulations.While an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental findings.The approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-secretase.In addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is discussed.Finally,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations of theγ-secretase-substrate complexes.Comprehensive understanding of the functional mechanisms ofγ-secretase will greatly facilitate the rational design of effective drug molecules for treating familial Alzheimer’s disease and perhaps Alzheimer’s disease in general.

The Tension Cosmology, Largest Cosmic Structures and Explosions of Supernovae from SST

Here, using the Scale-Symmetric Theory (SST) we explain the cosmological tension and the origin of the largest cosmic structures. We show that a change in value of strong coupling constant for cold baryonic matter leads to the disagreement in the galaxy clustering amplitude, quantified by the parameter S8. Within the same model we described the Hubble tension. We described also the mechanism that transforms the gravitational collapse into an explosion—it concerns the dynamics of virtual fields that lead to dark energy. Our calculations concern the Type Ia supernovae and the core-collapse supernovae. We calculated the quantized masses of the progenitors of supernovae, emitted total energy during explosion, and we calculated how much of the released energy was transferred to neutrinos. Value of the speed of sound in the strongly interacting matter measured at the LHC confirms that presented here model is correct. Our calculations show that the Universe is cyclic.

深水采油树Spring-Seal密封圈接触模型构建与实验测试

为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分析不同条件下S密封圈的密封性能,同时验证新建接触模型的合理性;利用实验测试S密封圈的实际密封效果。研究结果表明:S密封圈在高压、高温、低温等工况下能够长时间稳定工作且密封性能良好。研究结果可为S密封圈的接触研究及工程运用提供理论参考。

Temporal change of plankton size structure preserved by Lugol's solution:a FlowCAM study

Plankton size structure is crucial for understanding marine ecosystem dynamics and the associated biogeochemical processes.A fixation step by acid Lugol’s solution has been commonly employed to preserve plankton samples in the field.However,the acid Lugol’s solution can bias the estimation of size structure and the preserved plankton size structure can vary with time.Here,we explore the impact of sample storage time on the size-structure of the plankton community preserved by Lugol’s solution.Two short-term experiments and one long-term experiment were conducted to explore the change of plankton community size structure with the storage time:covering from a week to a month,and to nearly seven months based on particle-size data obtained by continuous Flow Cytometer and Microscope(FlowCAM)measurements.We found a linear change of plankton size with the storage time in short-term periods(less than 3 months)with a decrease of the slope but an increase of the intercept for the normalized biomass size spectrum(NBS S).However,there were opposite trends for NBSS with increasing slope but decreasing intercept after3 months.The potential causes of the distinct patterns of the NBSS parameters are addressed in terms of the interplay between particle aggregation and fragmentation.We found large changes in plankton biovolume and abundance among different size classes,which may indicate a distinct effect of acid Lugol’s solution on various plankton size classes.The mechanism driving temporal change in the size-structure of the Lugolfixed plankton community was further discussed in terms of particle aggregation and fragmentation.Finally,we emphasize that the effect of storage time should be taken into account when interpreting or comparing data of plankton community acquired from samples with various storage durations.

Sealing properties and structure optimization of packer rubber under high pressure and high temperature

During hydraulic fracturing operations of low-permeability reservoirs,packers are the key component to ensure the success of multistage fracturing.Packers enable sections of the wellbore to be sealed off and separately fractured by hydraulic pressure,one at a time,while the remainder of the wellbore is not affected.However,reliable sealing properties of the packer rubber are required to meet the high-pressure and high-temperature(HPHT)conditions of reservoirs(such as 70 MPa and 170 ℃).In this study,the structures of the packer rubber with two different materials are optimized numerically by ABAQUS and validated by experiments.The optimization process starts from the packer rubber with a conventional structure,and then,the weakest spots are identified by ABAQUS and improved by slightly varying its structure.This process is iterative,and the final optimized structure of a single rubber barrel with expanding back-up rings is achieved.For the structure of three rubber barrels with metallic protective covers,both HNBR and AFLAS fail under HPHT conditions.For the final optimized structure,the packer rubber made of AFLAS can work better under HPHT than that made of HNBR which ruptures after setting.The results show that the optimized structure of a single rubber barrel with expanding back-up rings and the material AFLAS are a good combination for the packer rubber playing an excellent sealing performance in multistage fracturing in horizontal wells.

Analysis of the sealing performance of combined sealing structure under deep-sea high pressure environment

For the requirement of safe and stable operation,the combined sealing structure was used for reciprocating motion in the deep sea high-pressure environment,and the effects of different seawater depths and shaft movement speed on the sealing performance of the combined sealing structure were studied.The change rule of the sealing performance of the combined sealing structure of reciprocating motion under different working conditions is proved.The study shows that in the combined sealing structure of reciprocating movement,the Von Mises stress and the contact stress of the O-ring varies with the direction of the shaft movement.The Von Mises stress and contact stress of the O-ring,the Von Mises stress and the contact stress on each sealing lip of the slip ring gradually increase with the increasing of seawater depths.At the same time,the Von Mises stress of the O-ring which in the process of the shaft upward movement is greater than the shaft downward movement,making the shaft upward movement more likely to cause the O-ring relaxation and fatigue.The shaft movement speed has no significant influence on the Von Mises stress and contact stress of the O-ring.The research results provide theoretical guidance and technical support for the selection and optimization of the geometrical parameters of the combined sealing structure in the deep-sea high-pressure environment.

Nonlinear Finite Element Analysis of the Structure of Door Seals

In order to evaluate the influence of the seal structure on door dosing force, nonlinear finite dement methed is introduced to analyze compression deformation of a door seal for SANTANA （name of the car made by Shanghai Volkswagen Co. Ltd）. MSC. Marc software is used to analyze the large deformation of the seal and the compression test is done to prove the computational results. The results show that the compression loads of the door seal are larger than the standard value of Shanghai Volkswagen Co. Ltd and the seal structure needs to be optimized. There are consistent relationships between calculating results and experimental results and the simulation method is effective.

A full-section asphalt concrete waterproof sealing structure for the high-speed railway subgrade

Purpose–This study aims to investigate the service performances of a new full-section asphalt concrete waterproof sealing structure(FSACWSS)for the high-speed railway subgrade through on-site tracking,monitoring and post-construction investigation.Design/methodology/approach–Based on the working state of the waterproof sealing structure,the main functional characteristics were analyzed,and a kind of roller-compacted high elastic modulus asphalt concrete(HEMAC)was designed and evaluated by several groups of laboratory tests.It is applied to an engineering test section,and the long-term performance monitoring and subgrade dynamic performance testing system were installed to track and monitor working performances of the test section and the adjacent contrast section with fiber-reinforced concrete.Findings–Results show that both the dynamic performance of the track structure and the subgrade in the test section meet the requirements of the specification limits.The water content in the subgrade of the test section is maintained at 8–18%,which is less affected by the weather.However,the water content in the subgrade bed of the contrast section is 10–35%,which fluctuates significantly with the weather.The heat absorption effect of asphalt concrete in the test section makes the temperature of the subgrade at the shoulder larger than that in the contrastive section.The monitoring value of the subgrade vertical deformation in the test section is slightly larger than that in the contrastive section,but all of them meet the limit requirements.The asphalt concrete in the test section is in good contact with the base,and there are no diseases such as looseness or spalling.Only a number of cracks are found at the joints of the base plates.However,there are more longitudinal and lateral cracks in the contrastive section,which seriously affects the waterproof and sealing effects.Besides,the asphalt concrete is easier to repair,featuring good maintainability.Originality/value–This research can provide a basis for popularization and application of the asphalt concrete waterproof sealing structure in high-speed railways.

Allozyme Diversity and Population Genetic Structure of Three Medicinal Epimedium Species from Hubei

Three Epimedium species, E. pubescens Maxim., E. sagittatum （Sieb. ＆ Zucc.） Maxim., and E. wushanense T. S. Ying, which are sympatrically distributed in the western Hubei Province, have been used in traditional Chinese medicine （TCM） for about 2,000 years. Genetic variability and population genetic structure of 11 natural populations of these Epimedium species were investigated using isoelectric focusing in thin-layer polyacrylamide slab gels. Of the 22 enzyme systems prescreened, six coding for 13 loci and 45 alleles were resolved, which were used for analyzing genetic diversity and population structure at both intraspecific and interspecific levels. The results showed that： l） high levels of genetic diversity were observed in all three species （A = 2.6-3.2, P = 69.2%-84.6%, Ho= 0.274-0.377, HE= 0.282-0.369）, which were higher than that of other herbaceous and aulmal-pollinated species with similar life-history characteristics; 2） there was significant deviation from Hardy-Weinberg Equilibrium, with one half of the loci showing heterozygote excess and the other homozygote excess, in all populations, suggesting the complicated breeding system of Epimedium species; 3） the low level of intraspecific and interspecific genetic differentiation （GST= 0.0246-0.0409 and 0.0495-0.1213, respectively） indicated a high level of gene flow among populations and close genetic relationship among the three species; and 4） UPGMA cluster analysis further showed that E. pubescens was more closely related to E. sagittatum than to E. wushanense, which was in good agreement with the morphological characters and the recent phylogenetic analysis of these species. On the basis of these results, it was concluded that the mixed breeding system, long-lived perennial life form, ancient evolutionary history, and seed dispersal by ants in Epimedium are responsible for the genetic variation and population structure of these species.

A study on deep structure using teleseismic receiver function in Western Yunnan

s Western Yunnan is located at the boundary of collision or underthrusting zone of Eurasian plate and is influenced by many times tectonic movements. With very complex geological environment and tectonic background, it is one of the seismically active areas. In the paper, the teleseismic records were selected from 16 national, local and mo-bile stations, including 4 very-wide-band mobile stations of PASSCAL. And nearly 2 000 receiver functions were extracted. Two measuring lines are 650 km and 450 km, respectively and across some major tectonic units in Western Yunnan. It is indicated that Nujiang might be a seam characterized by underthrusting. The western and eastern boundaries of Sichuan-Yunnan rhombus block, i.e., Honghe and Xiaojiang faults, might be an erection seam or collision belt. Panxi tectonic zone still has the characteristics of continental rift valley, that is, the surface is hollow and the upper mantle is upwarping. The tectonic situation in Western Yunnan is of certain regulation with the interlacing distribution of orogenic zone and seam. The crustal thickness decreases gradually from the north to the south and the S wave velocity is globally lower here.

双金属MOFs碳化材料的结构对锂硫电池正极性能的影响

利用硝酸钴和铁氰化钾在水溶液中沉淀反应以及ZIF-8在水溶液中的部分分解,分别制备了2种组成相近但结构不同的双金属有机框架前驱体Co-Fe precursor和ZCF precursor。经过多巴胺包覆,对2种产品在氩气气氛下退火获得碳化产物。将碳化产物与纳米硫粉混合得到的碳/硫复合材料(E-CoFeCN@C/S、E-ZCF@C/S)分别作为正极,组装扣式锂硫电池并测试电化学性能。利用X射线衍射仪、扫描电子显微镜、透射电子显微镜、热重分析仪进行形貌和结构分析。在组成相似的情况下,核壳结构碳载体(E-CoFeCN@C)与发散式结构碳载体(E-ZCF@C)对锂硫电池性能的影响呈现出“此消彼长”的特点:E-ZCF@C/S在循环伏安测试中表现出更小的极化以及更强的电流响应,在电化学阻抗测试中表现出更低的电荷转移阻抗,表明该材料有利于促进正极电荷传递过程,即加快电极反应动力学。E-ZCF@C/S在0.2C倍率下放电初始比容量为1211.3mAh/g,在2C倍率下放电初始比容量为794mAh/g,均优于E-CoFeCN@C/S。而核壳结构的优势主要体现在容量衰减方面,E-CoFeCN@C/S在0.2C倍率下经过100次循环后平均衰减率为0.074%(E-ZCF@C/S为0.26%),在2C倍率下循环300次后平均衰减率为0.047%(E-ZCF@C/S为0.13%),说明核壳结构对活性物质的锚固作用明显而对电荷转移不利。

HBsAg和HBsAb共存的慢性乙肝患者的血清学特征和S区突变位点

目的探讨HBsAg/HBsAb双阳患者和HBsAg单阳性患者的血清学差异,并对两组患者的HBV S区突变位点进行比较分析,探寻HBsAg/HBsAb共阳性患者可能的分子机制。方法选取首都医科大学附属北京佑安医院2022年6月至2023年3月的284例HBsAg/HBsAb双阳患者和519例HBsAg单阳患者,统计Age、ALT、AST、AST/ALT、TBiL、ALb、r-GT、HBsAg和HBsAg滴度、HBsAb、HBeAg、HBeAb、HBcAb、WBC,对两组患者的血清学指标进行比较分析。对HBV S区扩增成功的19例HBsAg/HBsAb双阳患者和19例HBsAg单阳患者进行测序分析,统计高频突变位点,分析HBV S区突变特征,探寻HBsAg/HBsAb双阳患者可能发生的分子机制。结果HBsAg/HBsAb双阳患者和HBsAg单阳患者在性别、HBeAg、ALT、AST、TBiL、r-GT差异有统计学意义(P<0.05)。两组患者在Age、HBeAb、HBcAb、AST/ALT、Alb、WBC差异无统计学意义(P>0.05)。HBsAg/HBsAb双阳组患者C基因型占78.95%(15/19),其中A113D/T、A317C/S、A45T、A86G、A87T、A96V、A97P等突变频率较高,HBsAg单阳组C基因型占84.21%(16/19),V159A、M47T、I213L、A317S、E44G、Q267L突变频率较高,两组患者的高频突变位点明显不同。结论双阳和单阳CHB患者血清学和基因突变位点存在显著差异。建议针对HBV S区不同的突变位点进一步研究HBsAg和HBsAb共存的机制。

中强地震发震构造标志浅析——以2023年积石山M_(S)6.2地震为例

地震地表破裂是地震发生的重要特征,是研究地震动力学、构造变形的重要手段。一般认为,M6 3/4以上的地震才会形成地表破裂。但近年来,也有M6.0左右的地震发生了地表破裂。本文旨在探讨中强地震地表破裂的识别方法。中强地震发震构造的识别具有一定的挑战性,主要表现在以下几个方面:(1)中强地震地表破裂的规模(位错量、宽度、长度和深度)较小,容易被黄土层厚覆盖,掩盖地表破裂的痕迹,不易识别;(2)非构造成因裂缝干扰,使得难以区分构造成因地表破裂。本文以2023年积石山M_(S)6.2地震为例,对中强地震构造成因破裂的识别标志进行了初步分析,提出了以下识别标志:(1)地表破裂几何展布和剖面形态,地震伴生的次生灾害(滑坡、崩塌、砂土液化等)的线性分布为识别发震构造提供参考和线索;(2)地表破裂沿破裂走向呈现稳定地穿越不同地貌单元,至少穿越一条沟谷等低凹地貌;(3)地表破裂在地质剖面上表现出稳定的产状;(4)地表破裂伴生构造形态,地表沿破裂发育雁列式褶皱(挤压鼓包)与张裂缝交替出现的现象。本文提出的识别标志为中强地震发震构造的识别提供了新的思路。

纳米C-S-H/PCE对蒸养UHPC力学性能增强机理研究

目前超高性能混凝土(UHPC)制品的力学性能有待进一步提升,采用纳米C-S-H/PCE对UHPC进行增强在理论上是一种可行的技术途径。本文研究了蒸养条件下掺入以聚羧酸(PCE)为分散剂的纳米水化硅酸钙(C-S-H/PCE)对UHPC力学性能的影响,通过测试水化热、水化产物、微观形貌和孔结构等对其机理进行了分析。结果表明,掺入3.0%(质量分数)纳米C-S-H/PCE可以显著提高蒸养UHPC的抗压强度和抗折强度。掺入纳米C-S-H/PCE可以促进UHPC的早期水化,生成更多的水化硅酸钙(C-S-H)凝胶,使水化放热温峰增高,并缩短达到水化温峰的时间。掺入纳米C-S-H/PCE可有效改善蒸养UHPC的孔结构,在掺量为3.0%(质量分数)时总孔隙率最小,有害孔比例最低。该研究可为纳米C-S-H/PCE在蒸养UHPC中的应用提供参考。

基于B/S的高校实验室预约管理系统设计与实现

为了实现实验室管理信息化,更好地为师生服务,文章设计并开发一套高校实验室预约管理系统。该系统是基于B/S结构,采用Vue视图框架、Nginx服务器及MySQL数据库构建而成的;支持专业实验室、教室和会议室的预约管理;入口对接华中科技大学统一身份认证系统,在校师生可直接使用已有的统一身份认证系统账号密码登录系统。用户可通过浏览器完成在线预约、预约查询、预约管理和数据统计等功能。该系统的应用提高了实验室管理的规范性和信息化程度。

Analysis of the Structure of Shakespeare's Sonnets

The sonnet is a kind of lyrics with restrict forms which cannot depart from the contents. Shakespeare's sonnets are like a valuable flower blossoming in the England poetry garden during the age of Renaissance and a bright pearl sparkling in the world's poetry treasury. This paper will analyze his sonnets from the perspective of the structure and then interpret the meanings behind those words, which can demonstrate the importance of the connection between the forms and the contents.

Effect of C/S Ratio on Morphology and Structure of Hydrothermally Synthesized Calcium Silicate Hydrate

The samples of the C-S-H series were synthesized by hydrothermal reaction of fumed silica, CaO and deionized water at initial C/S ratios between 1.0-1.7. Phase composition and structural and morphology characteristics of C-S-H samples were analyzed by XRD, IR and SEM. The experimental results showed that the d-spacing of （002）, （110） and （020） decreased, the d-spacing of （200） increased, and the d-spacing of （310） varied randomly, the polymerization of silica tetrahedra of C-S-H decreased, and morphology of C-S-H samples varied from sheet shapes to long reticular fibers as C/S ratio increased.

A welding document management software package based on a Client/Server structure

According to specifications for Welding Procedure Qualification of ASME IX Section and Chinese code, JB 4708 2000, a software package for managing welding documents has been rebuilt. Consequently, the new software package can be used in a Limited Area Network (LAN) with 4 different levels of authorities for different users. Therefore, the welding documents, including DWPS (Design for Welding Procedure Specifications), PQRs (Procedure Qualification Records) and WPS (Welding Procedure Specifications) can be shared within a company. At the same time, the system provides users various functions such as browsing, copying, editing, searching and printing records, and helps users to make decision of whether a new PQR test is necessary or not according to the codes above as well. Furthermore, super users can also browse the history of record modification and retrieve the records when needed.

A study on deep structure using teleseismic receiver function in Western Yunnan

s Western Yunnan is located at the boundary of collision or underthrusting zone of Eurasian plate and is influenced by many times tectonic movements. With very complex geological environment and tectonic background, it is one of the seismically active areas. In the paper, the teleseismic records were selected from 16 national, local and mo-bile stations, including 4 very-wide-band mobile stations of PASSCAL. And nearly 2 000 receiver functions were extracted. Two measuring lines are 650 km and 450 km, respectively and across some major tectonic units in Western Yunnan. It is indicated that Nujiang might be a seam characterized by underthrusting. The western and eastern boundaries of Sichuan-Yunnan rhombus block, i.e., Honghe and Xiaojiang faults, might be an erection seam or collision belt. Panxi tectonic zone still has the characteristics of continental rift valley, that is, the surface is hollow and the upper mantle is upwarping. The tectonic situation in Western Yunnan is of certain regulation with the interlacing distribution of orogenic zone and seam. The crustal thickness decreases gradually from the north to the south and the S wave velocity is globally lower here.