Benefits of Anthocyanin-Rich Black Rice Fraction and Wood Sterols to Control Plasma and Tissue Lipid Concentrations in Wistar Kyoto Rats Fed an Atherogenic Diet

Background: This study reports on the relative effects of administrating a cyanidin-3-O-glucoside-rich black rice fraction (BRF), a standardized wood sterol mixture (WS), and a combination of both to lower plasma and target tissue lipid concentrations in Wistar Kyoto (WKY) rats fed atherogenic diets. Methods: Male WKY (n = 40) rats were randomly divided into five groups, which included a nonatherogenic control diet and atherogenic diets that included a positive control and atherogenic diets supplemented with BRF or WS, respectively, and a combination of both BRF + WS. Plasma and target tissue liver, heart and aorta cholesterol, and triacylglycerides (TAG) content were also measured. Results: Rats fed atherogenic diets exhibited elevated hyperlipidemia compared to counterparts fed nonatherogenic diets (p < 0.001); this effect was mitigated by supplementing the atherogenic diets with BRF and WS, respectively (p < 0.05). Combining BRF with WS to enrich the supplement lowered cholesterol similar to the WS effect (p < 0.05) and lowered TAG characteristic to the BRF effect (p < 0.05). Conclusions: Rats fed diets containing BRF or WS effectively mitigate the hypercholesterolemia and elevated TAG induced by feeding an atherogenic diet. The benefit of adding BRF + WS together is relevant to the lipid parameter measured and is target tissue-specific.     

基于表面增强拉曼光谱技术的心肌生物标志物检测

心血管疾病(CVD)是全球最主要的死亡原因,急性心肌梗死(AMI)是心血管疾病致死的主要病因,安全快速地诊断AMI对于降低患者的死亡率至关重要。因常用的检测方法如心电图(ECG)缺乏足够的敏感性,寻找并针对AMI生物标志物开展高灵敏检测已成为早期检测AMI重要手段。心肌肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB)和肌红蛋白(Myo)是目前公认的检测AMI的重要心肌生物标志物。在过去的几十年里,许多生物传感器被开发出来用于检测心肌生物标志物,其中基于表面增强拉曼光谱(SERS)的心肌生物标志物检测技术迅速发展,并表现出独特的技术优势和广阔的应用前景。本文首先介绍了多种心肌生物标志物及其与AMI的关联,在此基础上概述主要的心肌生物标志物检测方法的原理、优势及局限性,重点介绍近年来新兴的SERS技术及其在心肌生物标志物传感方面的最新研究进展,并对该技术在AMI诊断方面的应用前景以及有待突破的瓶颈进行了讨论和展望。     

多孔氧化铝模板催化制备定向碳纳米管阵列

Well-aligned open-ended multi-walled carbon nanotube (MWCNT) arrays were prepared via chemical vapor deposition (CVD) method in porous anodic aluminum oxide (AAO) templates without depositing any transition metals as catalyst. Effects of the CVD temperature and heat treatment were studied in detail.Well-aligned open-ended MWCNT arrays were obtained at the CVD temperature above 600 ℃; when CVD temperature is reduced to around 550 ℃, CNTs, CNFs and other structures existed at the same time; no CNTs or carbon nanofibres (CNFs) could be found as the CVD temperature is below 500 ℃, and only amorphous carbon in the porous AAO template was found. Experimental results showed that the AAO template is catalytic during the CVD process, and it has the following two effects: to catalyze thermal decomposition of acetylene and to catalyze conversion of carbon decomposed from acetylene into CNTs or CNFs. Heat treatment could improve the graphitization degree, but it might also introduce new defects.     

Polymerization of 2,4-hexadiyn-1,6-diol by chemical vapor deposition

2,4-Hexadiyn-1,6-diol (HDO) was polymerized on glass and silicon plates by chemical vapor deposition without transition metal catalysis to form homogeneous thin films. Structural properties of the films were investigated by FT-IR, UV-visible, Raman, x-ray diffraction, and XPS spectroscopic analyses. The structure of CVD-polymerized HDO (CVD-PHDO) films was different from that of metathesis polymerized HDO (metathesis-PHDO), showing a polyacene-based structure but no polyene structure with acetylenic side groups. © 1996 John Wiley & Sons, Inc.     

SnSxSe2-x单晶纳米片的可控制备与表征

锡二硫族化合物可以通过改变硫和硒的含量来连续调控三元合金材料的带隙、载流子浓度等物理化学性质,在电子和光电子器件应用上具有巨大的潜力。本文采用化学气相沉积(CVD)技术可控地制备了不同元素组分的SnS_xSe_2-x(x=0,0.2,0.5,0.8,1.0,1.2,1.5,1.8,2.0)单晶纳米片。采用扫描电子显微镜(SEM)、原子力显微镜(AFM)、能量色散X射线光谱(EDS)、透射电子显微镜(TEM)以及拉曼光谱等手段对SnS_xSe_2-x纳米片进行了综合表征。结果表明本方法成功实现了元素百分比可调的SnS_xSe_2-x单晶纳米片的可控制备。重点研究了依赖于元素百分比的SnS_xSe_2-x的拉曼特征谱,实验结果与基于密度泛函理论(DFT)的第一性原理计算得到的SnS_xSe_2-x的拉曼仿真谱高度吻合,理论计算结果较好地诠释了实验拉曼光谱发生变化的原因。本研究提供了一种元素百分比可调的三元SnS_xSe_2-x单晶纳米片的可控制备方法,同时对锡二硫族化合物的明确、无损识别提供了方案。     

Molecularly engineered graphene surfaces for sensing applications: A review

Graphene is scientifically and commercially important because of its unique molecular structure which is monoatomic in thickness, rigorously two-dimensional and highly conjugated. Consequently, graphene exhibits exceptional electrical, optical, thermal and mechanical properties. Herein, we critically discuss the surface modification of graphene, the specific advantages that graphene-based materials can provide over other materials in sensor research and their related chemical and electrochemical properties. Furthermore, we describe the latest developments in the use of these materials for sensing technology, including chemical sensors and biosensors and their applications in security, environmental safety and diseases detection and diagnosis.     

Influence of axial coordination on the photophysical property of excited state of zinc porphyrin

The phenomenon that metalloporphyrins are coordinated to axial ligands is very common especially in green-plant and photosynthetic bacteria, where such coordination impacts a signifi-cant effect on both the primary charge separation in the reaction center and energy transfer in an-tenna systems[1]. In addition, it plays a key role in photodynamic therapy and medicine synthesis in a sense that some metalloporphyrins have been assembled by coordination bonds to anti-cancer drugs, enhancing the se…     

回收灯用钨丝在H2O2催化氧化环己酮合成己二酸中的应用

以回收灯用钨丝为催化剂前驱物,30％H2O2为氧源,催化氧化环己酮合成了己二酸,反应体系中无须使用有机溶剂、酸性助剂和相转移剂。 IR和TG分析表明,钨丝与H2O2反应生成的新生态过氧钨酸是催化活性成分,合成己二酸后转化为钨酸。 钨丝为催化剂前驱物合成己二酸适宜反应条件为：100 mmol环己酮,50 mL 30%H2O2,钨丝的摩尔用量为环己酮摩尔数的1.5%,回流反应6 h,己二酸收率63.7%。 比相同反应条件下用钨酸和WO3为催化剂的收率高10%~18%。     

热壁条件下油气的热着火现象

设计了高温热壁油气热着火实验系统,对受限空间油气混合气体在热壁条件下的热着火现象进行了实验研究。根据实验结果,详细讨论了油气混合物的着火方式、临界着火温度、着火压力范围以及体积分数、温度的变化规律。实验发现:热壁条件下油气混合物引燃分为油蒸气的热裂解-油气快速氧化反应-油气急速氧化反应3个阶段;油气混合物着火模式为燃烧、热爆燃和热爆炸;油气在汽油自燃点附近开始快速化学反应,热着火临界温度高于汽油自燃点近80 K;温度特征曲线在着火时具有突变性质;热壁温度达到783～873 K时,存在压力范围为2.2～17.6 kPa的三角形油气热着火压力半岛。     

增强型喷射器对爆轰波DDT过程的影响

在激波、火焰及射流同时存在的流场中,组织燃烧转爆轰过程是脉冲爆震发动机实现点火、起爆的关键问题。设计一类喷射器,采用C_2H_2/O_2/Ar反应,数值验证了该喷射器能增强爆震室燃料燃烧转爆轰的可行性,并讨论了流场中热点的点火机制。结果显示:该装置在流场中可激发不稳定性,产生漩涡,加速能量、质量的交换。流场产生热点,促进火焰速度加快,追赶前导激波。喷射器位置影响前导激波的运动速度。在一定范围内,前导激波速度越大,碰撞产生的热点越容易激发燃烧转爆轰过程。