Novel peptides from sea cucumber intestines hydrolyzed by neutral protease alleviate exercise-induced fatigue via upregulating the glutaminemediated Ca2+/Calcineurin signaling pathway in mice

Sea cucumber intestines are considered a valuable resource in the sea cucumber processing industry due to their balanced amino acid composition. Studies have reported that peptides rich in glutamate and branched-chain amino acids have anti-fatigue properties. However, the function of the sea cucumber intestine in reducing exercise-induced fatigue remains unclear. In this study, we enzymatically hydrolyzed low molecular weight peptides from sea cucumber intestines (SCIP) and administered SCIP orally to mice to examine its effects on exercise-induced fatigue using swimming and pole-climbing exhaustion experiments. The results revealed that supplementation with SCIP significantly prolonged the exhaustion time of swimming in mice, decreased blood lactate and urea nitrogen levels, and increased liver and muscle glycogen levels following a weight-loaded swimming test. Immunofluorescence analysis indicated a notable increase the proportion of slow-twitch muscle fiber and a significant decrease the proportion of fast-twitch muscle fiber following SCIP supplementation. Furthermore, SCIP upregulated mRNA expression levels of Ca²⁺/Calcineurin upstream and downstream regulators, thereby contributing to the promotion of skeletal muscle fiber type conversion. This study presents the initial evidence establishing SCIP as a potential enhancer of skeletal muscle fatigue resistance, consequently providing a theoretical foundation for the valuable utilization of sea cucumber intestines.     

Effect of the molecular structure of polyurethane elastomers on the thermomechanical properties of PUE/PC blends

Polyurethane elastomers (PUEs) based on 4,4′‐diphenylmethane diisocyanate (MDI), 1,4‐butanediol (BDO) and two kinds of aliphatic polycaprolactone (PCL) diols with molecular weight of 1000 Da and 2000 Da have been synthesized and melt‐blended with polycarbonate (PC). The compatibility of PC and PUEs was investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The results indicated that the glass transition temperature (T_g) of PC decreased by 0–40°C when 0–10 wt % of PUEs incorporated into the PC matrix. Phase separation in the blends was not detected by means of DSC characterization, but measurements of DMA and SEM indicated that phase separation existed in the blends of PC and PUEs synthesized with 1000 Da PCL‐diol. As for PUEs/PC blend in which 2000 Da PCL‐diol as PUEs' soft segments, it turned from completely compatible to partially when the NCO/OH ratio for the PUEs prepolymer was increased from 2 : 1 to 4 : 1. The compatibilities of PC and PUEs were greatly influenced by the molecular weight of polyols and the ratio of NCO/OH in the PUE prepolymer, higher molecular weight of polyols and lower NCO/OH ratio resulted in better compatibility. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

混合钢筋混凝土桁架在大跨度结构中的应用

在工程实践中常采用混合钢筋混凝土桁架来满足建筑上大跨度及结构转换的需要。结合两个工程设计实例,通过使用SATWE软件分析钢筋混凝土桁架内力及变形的变化规律。结果表明:在大跨度结构中采用混合钢筋混凝土桁架这种设计方案是可行和经济的,还给出了计算中应该注意的问题及设计构造措施。     

加权GM(1,1)模型在变形监测中的应用研究

灰色系统理论中的新信息对认知的作用大于老信息的作用,而传统的累加生成没有体现原始数据中新信息的重要性。为了充分利用新信息,本文结合工程实例将加权灰色系统理论GM(1,1)模型应用于滑坡工程进行变形预测,而且对权的选取做了初步讨论,从预测结果和实测结果进行对比分析,加权累加生成的GM(1,1)模型的模拟和预测精度比传统的GM(1,1)模型模拟和预测精度高,从而说明了该法的有效性和实用性。     

Cu-salen配合物催化大豆油环氧化合成环保塑化剂

以3,5-二叔丁基水杨醛和乙二胺(摩尔比2∶1)为原料合成了N,N’-二3,5 -二叔丁基水杨醛基乙二胺(salen配体),salen配体与Cu( OAC)2·H20的乙醇溶液混合回流得到Cu - salen配合物.对重结晶提纯后的salen配体及配合物进行了红外、紫外、核磁等表征.Cu - salen配合物作为大豆油环氧化反应催化剂,以叔丁基过氧化氢(TBHP)为氧源,最佳反应条件为:60℃下反应8h,催化剂用量为大豆油质量的2％,得到最佳环氧化效果,其环氧产物转化率为52.5％,选择性为59.6％.超声波辅助下,环氧值由2.2％提高到4.0％,环氧值提高了45％;转化率提高至71.4％,选择性提高到63.5％;反应时间由8h缩短至0.5h,催化剂用量减少为大豆油质量的0.5％.     

温拌橡胶沥青混合料在万柳中路的应用

分析了温拌橡胶沥青混合料的特点,介绍了北京地区温拌橡胶沥青混合料的设计方法和步骤,论述了橡胶沥青的生产,橡胶沥青混合料的拌和、摊铺、碾压等问题。温拌橡胶沥青混合料在万柳中路的成功应用,为其在北京地区的推广积累了工程经验。     

从INTERMAT2012看电动技术在小型挖掘机中的应用

2012年4月16日～21日在法国巴黎召开的INTERMAT2012,即使是在欧债危机的影响之下,各大工程机械相关制造商仍然热情高涨,在这个工程机械的盛宴上尽情地演绎,展出了许多各具特色的产品。作为工程机械业内最为著名的三大国际展会之一,本次展会聚集了行业内世界级知名企     

浓香型酒建窖窖泥厚度与微生物菌种群的关系研究

对浓香型酒建窖窖泥厚度与微生物菌种群的关系进行了研究,结果表明：窖壁泥的好氧细菌和好氧芽孢细菌数量为150mm厚度窖泥〉50mm厚度窖泥〉100mm厚度窖泥,厌氧细菌和厌氧芽孢细菌数量随着建窖窖泥厚度的增加呈逐渐增加趋势;而窖底泥的好氧细菌和好氧芽孢细菌数量则随着窖泥厚度的增加呈逐渐减少趋势,厌氧细菌和厌氧芽孢细菌数量与窖泥厚度没有相关性,不同厚度窖泥的霉菌和酵母菌数量均较少。     

多信息耦合下的充电站信息预测方法研究

为解决电动汽车用户在有充电需求时“充电站难寻”及充电时间等待问题,文章提出了多信息互联耦合下的电动汽车充电站运营状态预测方法,首先利用高德地图及e充网基于Python爬虫技术收集预测区域内的交通路况信息及充电站信息,分析所在地气象状况及周边交通状况与充电桩忙闲状态之间的相关性。最后采用深度信念网络预测模型对充电站的运营状态进行预测,以某充电站实际数据进行算例分析,结果表明所提出的预测模型能够更准确地对充电站内充电桩的使用数目进行预测,并验证该预测结果可为用户在未来短期时间段内的可用充电站提供依据,均衡充电站之间的设备利用率。     

高性能自修复水性聚氨酯制备及性能

首先将自制的5-(2-羟乙基)-6-甲基-2-氨基脲嘧啶(UPy)作为扩链剂与聚四氢呋喃(PTMG)、异佛尔酮二异氰酸酯(IPDI)进行预聚,然后将预聚物与亲水性扩链剂2,2-二羟甲基丙酸(DMPA)反应进行扩链,利用"丙酮法"制备了一种高性能自修复水性聚氨酯材料.通过傅里叶变换红外光谱、核磁共振氢谱对制备的材料进行结...