苦丁茶中熊果酸提取工艺研究

采用正交设计L6（4^5）组合了提取工艺，用高效液相色谱法对不同工艺下熊果酸的提取率进行了测定。确定苦丁茶中熊果酸的最佳提取工艺条件为：以95％乙醇为溶荆，料液比1：12，水浴回流3小时。提取3次，提取率达1．769％。     

Esters of para-aminobenzoic acid in cosmetics. Identification and dosage within sun-creams

A method is presented for the identification and determination by T.L.C. and G.L.C. of esters of para-aminobenzoic acid with a free amine function and of local anaesthetics, prohibited in cosmetic products, in accordance with the cosmetic directive 76/768/EEC. In a commercial product, nominally supplied as para-aminobenzoic monoglyceryl ester (authorised in sun-creams in accordance with the EEC directive) other phenyl groups with para substitution were identified by means of T.L.C. and N.M.R. spectroscopy; among them, the para-aminobenzoic ethyl ester. G.L.C. enables a quantitative determination of these substances. Les esters de l'acide para-amino benzoique dans les produits cosmétiques. Identification et dosage dans les crémes solaires     

苦丁茶多糖抗氧化活性研究

采用清除超氧阴离子自由基、清除羟自由基、清除DPPH自由基、双氧水诱导红细胞氧化溶血、红细胞自氧化溶血实验,对A、K_1、K_3三个苦丁茶多糖组分的抗氧化活性进行了研究,并与Vc进行了比较,结果表明:苦丁茶多糖对羟自由基、超氧阴离子自由基、DPPH自由基具有一定的清除作用;对H_2O_2诱导红细胞氧化溶血反应、对红细胞自氧化溶血反应都有显著的抑制作用。     

苦瓜和苦丁茶的抑菌作用及其袋泡茶的研制

对苦瓜和苦丁茶的有效成分进行提取，研究其抑菌作用。结果表明，苦瓜和苦丁茶的提取液对实验用食品常见污染菌有较强的抑制作用．并且具有热稳定性强、抑菌浓度低的特点。以苦瓜及苦丁茶为原料可制成袋泡茶．     

苦丁茶多糖的提取分离纯化及部分理化性质研究

以多糖提取率为指标,采用单因素实验和正交实验对苦丁茶多糖的提取工艺条件进行优化,确定最佳提取工艺为:水料比20:1、80℃、提取50 min。在此条件下,苦丁茶多糖提取率为2.43%,先后采用Sevag法脱蛋白、分级醇沉法、DEAE—52纤维素离子交换柱层析法对其进行分离纯化,最后得到K_1和K_22个组分。同时对各苦丁茶多糖进行理化性质分析,结合Sevag法预实验所得出的结果,推测苦丁茶多糖可能为以某种方式结合蛋白的糖缀合物。     

Essential role of Ubr11, but not Ubr1, as an N‐end rule ubiquitin ligase in Schizosaccharomyces pombe

The N‐end rule pathway degrades proteins bearing a destabilization‐inducing amino acid at the N‐terminus. In this proteolytic system, Ubr ubiquitin ligases recognize and ubiquitylate substrates intended for degradation. Schizosaccharomyces pombe has two similar Ubr proteins, Ubr1 and Ubr11. Both proteins have unique roles in various cellular processes, although the ubr1? strain shows more severe defects. However, their involvement in the N‐end rule pathway is unclear, and even the N‐end rule pathway‐dependent proteolytic activity has not been demonstrated in Sz. pombe. Here, we show that: (a) Sz. pombe has the N‐end rule pathway in which only Ubr11, but not Ubr1, is responsible; and (b) the C‐terminal fragment of the meiotic cohesin Rec8 (denoted as Rec8c) generated by separase‐mediated cleavage is an endogenous substrate of the N‐end rule pathway. Forced overexpression of stable Rec8c was deleterious in mitosis and caused a loss of the mini‐chromosome. In unperturbed mitosis without overexpression, the rate of mini‐chromosome loss was five‐fold higher in the ubr11? strain. Since Rec8 is normally produced in meiosis, we examined whether meiosis and sporulation were affected in the ubr11? strain. In unperturbed meiosis, chromosome segregation occurred almost normally and viable spores were produced in the ubr11? cells, irrespective of the presence of undegraded endogenous Rec8c peptides. Copyright © 2012 John Wiley & Sons, Ltd.     

苦丁茶冬青叶多糖KPS IIIa的热分析研究

采用热重、热重-红外联用及差示扫描量热法研究苦丁茶冬青叶多糖KPSⅢa的热稳定性。结果表明,苦丁茶冬青叶多糖在225℃以下只失去吸附水,在225～625℃间发生剧烈的裂解反应,产生水和二氧化碳;与肝素、淀粉、半乳糖及甲壳素的热分析比较,含有硫酸酯的苦丁茶冬青叶多糖和肝素的热稳定性较低,含氨基的甲壳素的热稳定性最好。说明苦丁茶冬青叶多糖在225℃以下相对稳定,不同的基团对多糖的热稳定性有很大影响。     

苦丁茶冬青叶多糖的分离纯化及其对羟自由基的清除作用

苦丁茶冬青叶经乙醇脱脂、水提醇沉和Sevag法除蛋白,得苦丁茶冬青叶粗多糖KPS Ⅱ.KPS Ⅱ经DEAE-纤维素阴离子交换层析柱分离纯化,得到两个纯化多糖组分KPS Ⅲ a和KPS Ⅲ b.KPS Ⅲ a和KPS Ⅲ b经过硫酸水解,还原乙酰化,用气相色谱方法测定了其组成及相对含量.KPS Ⅲ a与KPS Ⅲ b均主要由阿拉伯糖、木糖、甘露糖、半乳糖和葡萄糖组成,其摩尔比分别为10.21.01.28.05.4和17.71.01.11.84.1.以Fenton反应为产生·OH模型,用紫外分光光度法实验了苦丁茶冬青叶多糖(KPS Ⅱ、KPS Ⅲ a、KPS Ⅲb)对模型中产生的·OH的清除作用.结果表明,KPS Ⅱ、KPS Ⅲa、KPS Ⅲb对·OH都具有一定的清除作用,且清除率与多糖的浓度存在一定的量效关系.苦丁茶冬青叶粗多糖KPS Ⅱ对·OH的清除作用均比纯化多精(KPS Ⅲa、KPS Ⅲb)强.     

Distribution of Candida in the oral cavity and its differentiation based on the internally transcribed spacer (ITS) regions of rDNA

This study aimed to determine the distribution of Candida species in the oral cavity and differentiate the species based on PCR amplification, including HinfI and MspI digestion, in order to assess the effectiveness of using the rDNA region for species identification. Samples from saliva as well as palate, tongue and cheek mucosa surfaces were collected from 45 individuals, consisting of three groups: periodontal disease patients; denture‐wearers; and the control group. The samples were serially diluted, spread on BHI and YPD agar plates and scored for colony‐forming units (CFUs). Fifteen random candidal colonies were isolated and subjected to genomic DNA extraction, based on glass beads disruption. Four primers were used to amplify regions in the rDNA, and the ITSI‐5.8S‐ITSII PCR product was digested by HinfI and MspI restriction enzymes. The microbial loads on all sites of the denture‐wearers were found to be significantly higher than control, while in the periodontal disease group only the microbial loads on the tongue were significantly higher than control. Meanwhile, there was no significant difference at other sites. The restriction fragment lengths of the clinical samples were compared to those of seven control species, allowing the differentiation of all seven species and the identification of 14 species from the clinical samples. The MspI restriction digest was not able to distinguish between C. albicans and C. dubliniensis, whereas the HinfI digest could not distinguish between C. tropicalis and C. parapsilosis. It was concluded that PCR–RFLP of the candidal rDNA region has potential for species identification. This study demonstrates the potential use of candidal rDNA as a means for identifying Candida species, based on genotype. The results also indicate the possibility of constructing genetic probes that target specific restriction fragments in the ITSI‐5.8S‐ITSII region, enabling swift and precise identification of Candida species. Copyright © 2012 John Wiley & Sons, Ltd.     

Nicolas Appert: Inventor and Manufacturer

This article summarizes the life and work of Nicolas Appert, a famous French inventor and manufacturer. He devoted his life to the empirical development of the appertization process. His main objective was to offer to consumers, especially seamen, preserved foodstuff still having the appearance and properties of fresh fruit and vegetables. The inventor was in debt most of his life even though his discovery gave birth to a flourishing industry. This paper focuses on the main events in Appert's life and on the appertization process as described by Appert himself.     

苦丁茶中多酚类物质的分离纯化与结构解析

利用带二极管矩阵检测器的高效液相色谱仪(HPLC-DAD)分析苦丁茶冬青苦丁茶与绿茶多酚类化合物的组成,结果表明它们的色谱峰图呈现明显的不一致,说明苦丁茶冬青苦丁茶的主要化学成分可能不同于绿茶。利用半制备型HPLC从苦丁茶冬青苦丁茶中分离纯化得到了5种单体化合物,通过质谱(MS)和核磁共振(NMR)分析,将5种单体化合物分别鉴定为羟基酪醇葡萄糖苷、绿原酸、4,5-O-二咖啡酰奎尼酸、3,5-O-二咖啡酰奎尼酸和3,4-O-二咖啡酰奎尼酸。因此,认为苦丁茶冬青苦丁茶的主要多酚类化合物为绿原酸及其衍生物。     

Sequence requirements for Nalpha-terminal acetylation of yeast proteins by NatA

NatA is the major N-terminal acetyltransferase of the yeast Saccharomyces cerevisiae. In this study, we took advantage of our recent data on N-terminal acetylation of proteins of the yeast protein map to update the list of proteins with known NatA-dependent acetylation status. Furthermore, using the information available on the acetylation status of 100 novel proteins, we re-examined the rules for acetylation by NatA. The results refine our previous knowledge on NatA substrate specificity depending on the N-terminal and penultimate residues. In particular, we found that the acetylation frequencies of Ser-, Thr- and Ala-, the three residues most often acetylated by NatA, are higher than previously reported. In addition, comparison of the N-terminal region of acetylated and non-acetylated proteins revealed differences in amino acid composition that extend over the 25 first amino acid residues: acetylated proteins are characterized by a higher frequency of glutamate and glutamine and a lower frequency of lysine, arginine and histidine. We suggest that the particularities in amino acid composition of the N-terminal region of acetylated proteins facilitate its interaction with the Nat1p subunit of NatA and its guidance to the catalytic subunit Ard1p.     

苦丁茶冬青与大叶冬青苦丁茶提取物体外抗氧化活性的比较研究

比较苦丁茶冬青苦丁茶和大叶冬青苦丁茶提取液中多酚、黄酮的含量及体外抗氧化能力,结果表明：多酚含量高的苦丁茶冬青苦丁茶比黄酮含量高的大叶冬青苦丁茶具有较高的体外抗氧化能力;对5 种体外抗氧化活性评价方法之间的相关性进行分析,表明各抗氧化方法间相关性良好(R2 ＞ 0.8478),尤以DPPH 自由基法与ABTS＋·法的相关性最高(R2=0.9967)。     

绿藻果汁复合饮料的工艺研究

绿藻是营养价值和药用价值兼具的海洋蔬菜，本方文论述了以干浒苔为绿藻原料，配以复合果汁生产绿藻果汁复合饮料的工艺配方和技术关键，着重阐述了绿藻去腥的方法，并提出了产品的质量标准。     

苦丁茶多糖活性成分动态累积及其抑菌活性

目的：研究苦丁茶（Ilex kudingcha C. J. Tseng.）中主要抑菌活性成分多糖在不同采收月份的动态累积规律。方法：将不同采收期的苦丁茶叶水浴回流提取3 次,用杯碟法分别测定其对大肠杆菌、金黄色葡萄球菌和绿脓杆菌3 种菌的抑菌圈直径,比较不同采收期苦丁茶水提物抑菌圈直径大小,确定最佳采收期。通过苯酚硫酸法测定不同采收期苦丁茶提取物中多糖含量,分析多糖含量与苦丁茶抑菌能力之间相关性;同时采集不同采收期红外光谱,分析与多糖相关的特征峰强度变化规律及其与抑菌活性之间的相关性。结果：在一年的不同月份生长期内,苦丁茶多糖含量在1-3月份逐渐增加,4月份达到最大值96.6 mg/g,然后呈缓慢下降的趋势,7-10月变化不大,11月份后含量显著降低,12月达到全年最低值47.7 mg/g。苦丁茶水提物对大肠杆菌、金黄色葡萄球菌和绿脓杆菌3 种菌的抑制作用在4月份最大, 12月份最小,与苦丁茶多糖含量的变化规律基本一致。结论：苦丁茶抑菌活性多糖成分4月份含量最高,为最佳采收期;苷类和多糖为苦丁茶抑菌活性成分。     

服装压力测试装置的设计研究

应用FSL05N2C型压阻式传感器，结合高性能的放大电路及温度补偿电路，通过ICL7107MD转换器进行模拟信号与数字信号的转换并在LED显示输出，进行服装压力测试装置的研制。该装置为服装压力舒适性的客观评定提供了依据和基础。