基质固相分散-高效液相色谱法同时测定冬虫夏草和蛹虫草中的9种核苷及碱基

目的:建立基质固相分散-高效液相色谱法（MSPD-HPLC）同时测定野生冬虫夏草、深层发酵培养的蛹虫草菌丝体和固态培养的蛹虫草子实体中的腺嘌呤、腺苷、胸腺嘧啶、胸苷、尿嘧啶、尿苷、胞嘧啶、鸟苷和虫草素。方法:采用MSPD-HPLC法同时测定上述9种核苷及碱基。结果:MSPD提取条件为:弗罗里硅土为分散剂,分散剂与样品质量比为4∶1,15mL石油醚为淋洗剂,15mL甲醇为洗脱剂。标准曲线在线性范围内具有较好的线性关系（r>0.9997）,化合物的检出限和定量限分别为12.4⁷9.4ng·mL-1和41.2²64.6ng·mL-1。日内和日间精密度均低于7.28%。样品加标回收率在81.54%⁹5.77%之间。结论:本法简单快速,样品用量少,可广泛应用于中草药和生物药品中核苷和碱基的同时测定。      

振动格栅紊流及其应用综述

摘要：振动格栅紊流是一种无平均流动的特殊紊流,在一定范围内呈各向同性。这类紊流具有许多不同于明渠水流的特点,易于人工控制,可以研究与环境工程有关的水力学问题。本文回顾了近期振动格栅紊流及应用的主要研究成果,包括紊流结构的研究、无平均流动的紊流条件下泥沙运动规律、气液、固液交界面处的质量转移等,侧重于介绍重要的实验结论及量测手段。针对前人研究的不足,提出了进一步的研究方法,并对振动格栅紊流的研究趋势进行了讨论。     

Effect of multiple bluff bodies on hydrogen/air combustion characteristics and thermal properties in micro combustor

The bluff body is commonly used to improve micro combustion. The micro combustor with multiple rectangular bluff bodies in a single row was proposed. The effects of bluff bodies on H₂/air combustion characteristics were numerically studied. The temperature distributions, ignition position, combustion efficiency and blow-out limit were investigated via changing the total width and number of bluff bodies. The results show that the combined use of multiple bluff bodies can further expand the blow-out limit of H₂/Air. The effect of high temperature and viscous force on the flow velocity is main factors for the flame morphology. When the total width of bluff bodies is 2 mm, the blow-out limit decreases with the increase of bluff body number. When the total width of bluff bodies is 4 mm and 6 mm, the blow-out limit increases with the increase of the number of bluff bodies. With the increase of inlet velocity, the complete combustion efficiency decreases. The combustion efficiency in the combustor with wider blow-out limit decreases more slowly. It indicates that the combustor with multi-bluff bodies is more suitable for the operation conditions with high flow velocity.     

Entropically Driven Fabrication of Binary Superlattices Assembled from Polymer-Tethered Nanocubes and Nanospheres

The spontaneous organization of two types of nanoparticles (NPs) with different shapes or properties into binary nanoparticle superlattices (BNSLs) with different configurations has recently attracted significant attention due to the coupling or synergistic effect of the two types of NPs, providing an efficient and general route for designing new functional materials and devices. Here, this work reports the co-assembly of polystyrene (PS) tethered anisotropic gold nanocubes (AuNCs@PS) and isotropic gold NPs (AuNPs@PS) via an emulsion-interface self-assembly strategy. The distributions and arrangements of the AuNCs and spherical AuNPs in the BNSLs can be precisely controlled by adjusting the effective size ratio (λ_eff) of the effective diameter (d_eff) of the embedded spherical AuNPs to the polymer gap size (L) between the neighboring AuNCs. λ_eff determines not only the change of the conformational entropy of the grafted polymer chains (∆S_con) but also the mixing entropy (∆S_mix) of the two types of NPs. During the co-assembly process, ∆S_mix tends to be as high as possible, and the −∆S_con tends to be as low as possible, leading to free energy minimization. As a result, well-defined BNSLs with controllable distributions of spherical and cubic NPs can be obtained by tuning λ_eff. This strategy can also be applied for other NPs with different shapes and atomic properties, thus largely enriching the BNSL library and enabling the fabrication of multifunctional BNSLs, which have potential applications in photothermal therapy, surface-enhanced Raman scattering, and catalysis.     

Targeted Delivery of Apoptotic Cell-Derived Nanovesicles prevents Cardiac Remodeling and Attenuates Cardiac Function Exacerbation

The modulation of inflammatory responses plays an important role in the pathobiology of cardiac failure. In a natural healing process, the ingestion of apoptotic cells and their apoptotic bodies by macrophages in a focal lesion result in resolution of inflammation and regeneration. However, therapeutic strategies to enhance this natural healing process using apoptotic cell-derived biomaterials have not yet been established. In this study, apoptotic bodies-mimetic nanovesicles derived from apoptotic fibroblasts (ApoNVs) conjugated with dextran and ischemic cardiac homing peptide (CHP) (ApoNV-DCs) for ischemia-reperfusion (IR)-injured heart treatment are developed. Intravenously injected ApoNV-DCs actively targeted the ischemic myocardium via conjugation with CHP, and are selectively phagocytosed by macrophages in an infarcted myocardium via conjugation with dextran. ApoNV-DCs polarized macrophages from the M1 to M2 phenotype, resulting in the attenuation of inflammation. Four weeks after injection, ApoNV-DCs attenuated cardiac remodeling, preserved blood vessels, and prevented cardiac function exacerbation in IR-injured hearts. Taken together, the findings may open a new avenue for immunomodulation using targeted delivery of anti-inflammatory nanovesicles that can be universally applied for various inflammatory diseases.     

Update on potential of edible mushrooms: high-value compounds,extraction strategies and bioactive properties

The traditional and growing importance of mushrooms due to their rich composition in nutritive and bioactive compounds converts the whole feedstock and their fractions into versatile attractive ingredients for food and nutraceuticals. The processing conditions are critically relevant to selectively recover high-valuable compounds in a sustainable way. This short review, covering scientific papers published in the last 2 years, offers an updated vision of the study and applications of edible mushroom bioactive compounds, covering aspects in relation to the novelties in the cultivation, isolation, identification, characterisation of chemical and biological properties, extraction technologies and purification, as well as food applications, particularly in novel foods.     

连续体结构的变密度拓扑优化方法研究

为了实现使连续体结构的体积约束和柔顺度最小的拓扑优化及解决采用经典变密度法引起的结构优化结果存在如灰度单元、棋盘格等数值不稳定问题,提出了一种新的拓扑优化方法。首先,采用改进的固体各向同性材料惩罚法作为材料插值方案,建立结构拓扑优化模型;其次,通过引入基于高斯权重函数的敏度过滤法和设计新灰度单元抑制算子来解决数值不稳定问题;最后,借助优化准则法求解优化模型。通过算例分析可知：新策略可以改进拓扑优化方法;新的拓扑优化方法具有收敛速度较快、能更好地获取柔顺度小且拓扑构型好的优化结构和抑制灰度单元产生等优势。研究结果为其他连续体结构的拓扑优化研究提供了新思路。     

Physicochemical Properties and Stabilities of Crude and Purified Oil Bodies Extracted from High Oleic Peanuts

Physicochemical properties and emulsion stabilities of two types of oil bodies—crude oil bodies (COB) and purified oil bodies (OB)—recovered from high oleic peanuts via an aqueous enzymatic extraction process are investigated. RGB color analysis and flavor volatiles identification reveal that both COB and OB present desirable color and acceptable flavor. OB tends to have stronger antioxidant capacity and higher nutritional value compared to COB according to results from fatty acids, amino acids, and tocopherol analyses. The emulsification of oil bodies shows a slightly lower level than lecithin, but excellent thermal stability and storage stability (especially for OB), which relates greatly to small particle size, high zeta‐potential, and high content of hydrophobic amino acids. The freeze–thaw stability of OB is poorer than that of COB, which may relate to the presence of impurities in oil bodies. Thus, the peanut oil bodies, especially purified oil bodies, are proven to be advantageous emulsifying agents and additional valuable sources of antioxidants. Practical Applications: The results in this work clarify the differences in physiochemical composition and the fundamental emulsifying properties between COB and OB, and demonstrate the possibility of replacing traditional emulsifiers by natural green emulsifiers (e.g., oil bodies) in the food industry. Moreover, oil bodies extracted from high oleic peanuts, which contain plenty of unsaturated fatty acids and tocopherols, are a potential source for food supplements. In the long term, this work will increase the industrial conversion rate of oil bodies, enhance the processing and utilization level of high oleic peanuts, and promote the development of new foods based on peanut resources.     

Miniaturization of patch antenna based on hybrid topology optimization

A hybrid topology optimization method that combines the scalar isotropic material with penalization and the level set method is utilized to achieve the miniaturization of patch antennas while maintaining good radiation and polarization characteristics. In order to achieve this goal, the Heaviside projection filter is applied to obtain topologies that are more complex. Both the radiation power and the reflection coefficient of the antenna are utilized as sub‐objectives. Besides, by setting the radiation patch to be symmetrical, not only the numbers of optimization variables and optimization sub‐objectives are reduced, but also the cross‐polarization level is suppressed effectively, so that the optimization is accelerated. The optimized patch antenna achieves good performance in patch size, impedance matching, radiation pattern, gain, and polarization characteristics. Compared with the reference patch antenna, the patch size of the optimized antenna is reduced by 63%, while the maximum realized gain and efficiency remain basically unchanged, achieving more than 5.9 dBi and 90%, respectively. Due to its very small size patch, the antenna is particularly suitable for compact multi‐antenna and antenna array applications.     

Ice stress-strain curve prediction in uniaxial compression loading in the objective of atmospheric icing risk evaluation

Atmospheric icing is a major cause of damage to electric power networks. During ice storms, “ice shedding off” cables and conductors can lead to major damage to power systems, mostly by mechanical failure. The brittleness of ice might be its most important and critical property possibly leading to hazardous events in urban regions, and involving equipment such as electrical power lines. To avoid or reduce the risks from this phenomenon, it is necessary to understand the mechanical behavior of ice, including ice strain, as well as its maximal strength and residual strength. The behavior of ice depends mainly on the applied stress and strain rate, as well as temperature, salinity, porosity, and particle size. As a fundamental subject on the deformation behavior of ice, the simple case of polycrystalline isotropic ice was chosen in this study. A methodology is developed to determine the stress-strain curve for ice as a function of temperature and several uniaxial compression loading conditions. Mathematical relations are developed for several loading conditions and temperature. The results of this research allow to predict the maximal and residual strength of ice, as functions of strain rate and temperature.