无花果果皮中花青素的提取工艺的建立

本研究使用单因素方法考察了无花果(Ficus carica L.)果皮中花青素的最佳提取条件,并考察了7种参数对花青素提取率的影响。参数设置如下:溶剂性质(水,甲醇,乙醇和丙酮)、提取次数(1~3次)、固液比(1/50,1/100,1/150和1/200)、提取时间(60 min,120 min,180 min和240 min)、甲醇浓度(0,20%,40%,60%,80%和100%)、酸类型(盐酸,乙酸,柠檬酸和酒石酸)和酸浓度(0,1%,2%,5%和10%)。使用pH-示差法测量无花果果皮中单体花色素的含量。研究显示,无花果果皮中花青素的最佳提取条件为:溶剂为甲醇溶剂,提取次数为2次,固液比为1/100,提取时间为180 min,甲醇浓度为80%,酸类型为柠檬酸,柠檬酸浓度为5%。该最佳提取条件下的花青素的提取率达到最高(345.62 mg/100g DS)。     

A mechanistic model on the role of “radially-running” collagen fibers on dissection properties of human ascending thoracic aorta

Aortic dissection (AoD) is a common condition that often leads to life-threatening cardiovascular emergency. From a biomechanics viewpoint, AoD involves failure of load-bearing microstructural components of the aortic wall, mainly elastin and collagen fibers. Delamination strength of the aortic wall depends on the load-bearing capacity and local micro-architecture of these fibers, which may vary with age, disease and aortic location. Therefore, quantifying the role of fiber micro-architecture on the delamination strength of the aortic wall may lead to improved understanding of AoD. We present an experimentally-driven modeling paradigm towards this goal. Specifically, we utilize collagen fiber micro-architecture, obtained in a parallel study from multi-photon microscopy, in a predictive mechanistic framework to characterize the delamination strength. We then validate our model against peel test experiments on human aortic strips and utilize the model to predict the delamination strength of separate aortic strips and compare with experimental findings. We observe that the number density and failure energy of the radially-running collagen fibers control the peel strength. Furthermore, our model suggests that the lower delamination strength previously found for the circumferential direction in human aorta is related to a lower number density of radially-running collagen fibers in that direction. Our model sets the stage for an expanded future study that could predict AoD propagation in patient-specific aortic geometries and better understand factors that may influence propensity for occurrence.     

高温胁迫对枇杷果皮热伤害的抗氧化特性影响

为探讨枇杷[Eriobotrya japonica(Thunb.)Lindl.]对高温胁迫的响应,对‘红种’枇杷果皮热伤害的抗氧化特性进行研究。结果表明,在自然光下,枇杷果皮热伤害的阈值为40℃(1.5 h),且果皮热伤害与温度和持续时间关系密切,光照可促进热伤害的发生。枇杷果皮受热伤害程度与果实本身的营养状态有关,果肉维生素C(Vc)、钙(Ca)含量越低,果皮热伤害级数越高。与25℃相比,40℃高温处理增加了果皮的超氧阴离子和丙二醛(MDA)含量,而超氧化物歧化酶(SOD)、过氧化物酶(POD)的活性呈下降趋势。这揭示了高温胁迫下枇杷果皮对热伤害的抗氧化响应机制。     

Application of white cellulose acetate sheets on fossil wood investigation

Generally, transparent cellulose acetate sheets as a peel technique material are used in the identification of fossils, whereas white cellulose acetate sheets as a biochemistry technique material are applied in serum protein electrophoresis (SPE). Here we report the application of white cellulose acetate sheets for identifying a polished fossil wood from the Upper Mesozoic of West Liaoning, China. Based on the characters of transverse, radial, and tangential sections, the fossil wood is ascribed to a taxon of Protoglyptostroboxylon sp. Compared with transparent cellulose acetate sheets, white cellulose acetate sheets not only provide the similar information as that of the former, but also are more easily acquired in the Chinese market than the former. Because peel technique supported by white cellulose acetate sheets has the advantages of simple, time-saving, safe, reliable, and practical operation with lower material loss, it is a very good choice for the polished fossil wood investigation in labs, museums, geological parks, and handicraft shops. It is also a convenient approach to training students to learn the anatomic structure of fossil wood.     

Molecular Cloning and Characterization of a NAC-like Gene in “Navel” Orange Fruit Response to Postharvest Stresses

A cDNA subtraction library had been constructed to identify differentially expressed genes in peel pitting of citrus fruit. Based on the sequence of a cDNA fragment homologous to NAC gene family, the full-length cDNA of 1,203 nucleotides was cloned from “navel” orange by rapid amplification of cDNA ends. It was designated as CsNAC, encoding a protein of 305 amino acids. The calculated molecular weight of the CsNAC protein was 35.2 kDa, and theoretical isoelectric point was 6.72. Sequence comparison showed that the CsNAC protein had a strikingly conserved region at the N terminus, which is considered as the characteristic of the NAC protein family. CsNAC protein was orthologous to Arabidopsis thaliana ATAF1. Phylogenetic analysis confirmed CsNAC belonged to the ATAF subfamily, which plays an important role in response to stress stimuli. RNA gel blot analysis showed that the expression of CsNAC gene was rapidly and strongly induced by stresses such as wounding and no oxygen. Low temperature (4°C) and exposure to ethylene also increased the expression level of CsNAC gene. However, its expression was suppressed by high temperature (40°C) but not affected by low oxygen (3%). Our results may provide the basis for future research of NAC-like gene’s role in stress-induced citrus peel pitting. Sequence data of CsNAC from this article have been deposited at GenBank under accession number EF596736.     

Expression of a senescence-associated cysteine protease gene related to peel pitting of navel orange (Citrus sinensis L. Osbeck)

Previously, a suppression subtractive hybridization library was constructed to identify differentially expressed genes in peel pitting of navel orange fruit and a cDNA fragment sharing high similarities to cysteine protease genes was identified. In this study, we cloned its full-length cDNA sequence, designated CsCP, using the Rapid amplification of cDNA ends approach. It consists of 1,409 nucleotides and its ORF encodes 361 amino acids predicted to have an N-terminal signal peptide. Phylogenetic analysis revealed that CsCP belonged to the aleurain group in papain family of cysteine proteases. According to quantitative RT-PCR, the expression of CsCP was enhanced during the development of postharvest peel pitting concomitant with senescence, although it was detectable in all tested tissues including root, leaf, flower and peel of fruit. RNA gel blot analysis showed that the CsCP expression was induced by hypoxia (3% O₂), but repressed by anoxia (0% O₂), wounding, ethylene and high temperature (40°C). Conclusively, the CsCP is a senescence-associated gene and up-regulated during the development of citrus postharvest peel pitting, which provides a basis to understand its role in citrus peel pitting.     

Effect of several factors on the mechanical properties of pressure-sensitive adhesives used in transdermal therapeutic systems

The effects of coating thickness, type of adhesive, and type and concentration of enhancer on the mechanical properties of two acrylic pressure-sensitive adhesives (PSAs) were investigated using a 2(4) factorial design and an optimization technique. Sixteen formulations containing 0% or 10% of either caprylic acid or methyl laurate in two different PSAs, namely Duro-Tak 87-2196 and Duro-Tak 87-2097, were prepared. The adhesive properties of these laminates were evaluated by applying the 90 degrees Dynamic Adhesive Strength Peel Test (90 degrees DASPT) and 1800 Release Liner Peel Test (180 degrees RLPT). Coating thickness, concentration of enhancer, and type of adhesive did affect the 90 degrees DASPT. For the 180 degrees RLPT, the most significant factors were coating thickness and concentration of enhancer, with a strong interaction observed between the two. Coating thickness and concentration of enhancer were also used to create mathematical models that correlated these factors with the mechanical properties of the PSAs. For this purpose, the optimization technique 3(2) was applied. It was found that the correlation of the above factors can be adequately described with polynomial equations, which can be used for predicting the mechanical properties of the laminates containing the above PSAs and methyl laurate (0%-10%).     

温州蜜柑果实发育期叶片和果皮吸收~(32)P的研究

应用同位素示踪技术,研究了宫川温州蜜柑果实发育期叶片、果皮对３２Ｐ的吸收速率和转化形式。结果表明：在湖南气候条件下,叶片、果皮能以不同速率利用其表面~（３２）Ｐ并进一步转化为蛋白质、核酸、醚溶性磷和磷脂。果皮吸收３２Ｐ的性能弱于叶片,没有出现第二次吸收高峰,而是随油胞数量增加、蜡质层加厚、细胞老化而逐渐减弱,且吸收的３２Ｐ绝大部分仍滞留于果皮中。     

龙眼果皮显微结构与果实耐贮性关系探讨

龙眼 ( Euphoria longan) ,又称桂圆 ,是我国南方一种名优水果 ,香甜可口 ,营养丰富 ,不但可鲜食 ,而且可做药用 ,具补心益脾 ,养血安神等作用 ,作为一种名贵补品深受人们喜爱。近年来龙眼的栽培面积不断扩大 ,产量不断提高 ,龙眼的贮藏保鲜问题也越来越受到人们的关注。笔者通过不同品种龙眼耐贮性、显微结构间的差异 ,探讨采后龙眼感病腐烂的原因 ,为龙眼的贮藏保鲜提供理论依据。1 　材料和方法1 .1 　材料选择广东省栽培历史悠久、栽培面积最大的名优品种石硖和鲜果综合商品性状最好的储良为实验材料。实验用果采自广州从化地区。1 999…     

Comparison Study of Synthesized Red (or Blood) Orange Peels and Juice Extract-Nanoflowers and Their Antimicrobial Properties on Fish Pathogen (Yersinia ruckeri)

AbstractIn this work, we synthesized blood orange peel extract-copper (II) (Cu²⁺) ions nanoflower (NFs) and blood orange juice extract-copper (II) (Cu²⁺) ions nanoflower examine their antimicrobial properties on the fish pathogen (Yersinia ruckeri). The main compounds of the blood orange peel extract and the blood orange juice extract were organic components, and the copper (II) (Cu^{2 +}) ions were inorganic components. BOPE-Cu^{2 +} nanoflowers are quite compact, porous, and uniform as compared to BOJE-Cu²⁺ nanoflowers. Scanning Electron Microscopy, Fourier Transform Infrared spectrometry, and Energy-Dispersive X-ray spectroscopy were used to observe the structures of the NFs. The findings of FT-IR show Cu–O and Cu–N bonds in NF, which may be an indicator of the development of NFs. Although the antimicrobial actions of BOPE-hNFs and BOJE-hNFs against Yersinia ruckeri (NCTC 12,268) have been confirmed.Graphic Abstract