紫玉米花青素的微胶囊化研究

花青素作为植物界广泛存在的一种天然食用色素,安全、无毒、资源丰富,而且具有一定营养和药理作用,然而花青素对pH值、氧气、温度、光、金属离子等十分敏感。拟利用微胶囊化技术,保护花青素的抗氧化特性,并比较了2种常用的微胶囊方法（喷雾干燥法和锐孔法）的包埋效果,以期为花青素的使用提供一定参考。结果表明,啧雾干燥法制备紫玉米花青素微胶囊效果较锐孔法更好,而且当选择麦芽糊精和阿拉伯胶1：1作喷雾干燥的壁材,芯材（花青素）与壁材按1：16制备时,其包埋率可达34％,效果最佳。     

嗜热毛壳菌(Chaetomium thermophile)液体发酵产生纤维素酶及酶学性质的研究

探讨了嗜热真菌Chaetomium thermophile产生纤维素酶的液体发酵条件及滤纸酶(FPA)的特性。采用液体发酵培养法,通过对碳源、氮源、培养时间、培养基的起始pH值及产酶过程中pH值和蛋白质含量变化的研究发现：在2％纤维素、1％可溶性淀粉为碳源;2．0％KNO3 0．2％酵母粉为氮源;起始pH值为6．5,50℃下培养9d后,各种酶活最高。发酵过程中,pH值和蛋白质的含量均在前3d下降,后升高。FPA的反应最适温度和pH值分别为60℃和5．5～6．0;且具有较高的热稳定性和DH稳定性。     

宇佐美曲霉L336酸性蛋白酶的动力学性质*

L336酸性蛋白酶的分子量为54000,等电点为3．8±0．2。在pH2．5,40℃条件下,酶对酪蛋白、牛血清白蛋白和牛血红蛋白的Km值分别为0．263g／L、0．278g／L和0．415g／L,Vmax分别为2075、1550和2793μgTyr／min、mL,酪蛋白为最适底物。在pH2．0～5．0、40℃以下时酶的稳定性最好。此外,还研究了金属离子对酶活性的影响。     

宇佐美曲霉L336酸性蛋白酶的动力学性质

L336酸性蛋白酶的分子量为54000,等电点为3．8±0．2。在pH2．5,40℃条件下,酶对酪蛋白、牛血清白蛋白和牛血红蛋白的Km值分别为0．263g／L、0．278g／L和0．415g／L,Vmax分别为2075、1550和2793μgTyr／min、mL,酪蛋白为最适底物。在pH2．0～5．0、40℃以下时酶的稳定性最好。此外,还研究了金属离子对酶活性的影响。     

枯草芽胞杆菌微生态制剂的研制

采用液体发酵工艺,确定枯草芽胞杆菌的最适发酵条件为:发酵温度30℃,初始pH值7.2,并以1%海藻酸钠和3%明胶组成的混合胶体溶液为囊壁材料,以4%氯化钙作固化剂将枯草芽胞杆菌制成微胶囊剂,稳定性试验结果显示经微胶囊包埋的枯草芽胞杆菌制剂,室温下保存1个月,活菌存活率为98.8%,保存3个月,活菌存活率为50.6%,保存6个月,活菌存活率为15.7%,均高于未经微胶囊化的样品;在4℃冷藏下保存3个月,未经微胶囊化的样品活菌存活率仅为经微胶囊包埋制剂的66.2%。该微胶囊制剂提高了活菌存活率,延长了活菌常温保存期。     

黑莓果实色素的稳定性分析

研究了光照、温度、pH值、氧化剂（H2O2）和还原剂（Na2SO3）对黑莓（Rubus spp．）果实色素水溶液稳定性的影响。结果表明,黑莓果实色素为水溶性花色苷类化合物,对光和热有较好的耐受性,对pH、H2O2和Na2SO3较敏感,且耐还原性略强于耐氧化性。在小于pH4．0、温度低于50℃及避光条件下黑莓果实色素的稳定性较好,可作为食品色素添加剂使用。     

磁性固定化胰蛋白酶的催化特性及应用的研究

详细研究了磁性固定化胰蛋白酶的催化特性,并与溶液酶进行比较,发现胰蛋白酶经固定化后最适pH值向碱性方向移动了1．0个pH单位,最适温度提高了5℃,K值略有增大。对该固化酶的热稳定性和操作稳定性也进行了研究,结果表明,胰蛋白酶经固定化后热稳定性明显提高,操作稳定性也得到了一定的改善,经3次重复使用后,活性保持43．8％,对啤酒澄清和裸皮软化显示较好的应用前景。     

影响白腐真菌J610-D对染料苋菜红脱色降解的培养因素

建立白腐真菌J610-D与苋菜红的共培养体系,研究培养参数对染料脱色降解的影响。结果表明：（1）在含缓冲成分的系统中,菌种J610-D在pH值4．5的培养液比pH值3．0有利于反应进行,浅层培养较深层培养好,缓冲成分差别的作用不明显。（2）在不舍缓冲成分的系统中,生长与反应阶段培养液均为pH值4．5时,效果最佳;生长于pH值4．5,反应在pH值3．0脱色率和降解率高于生长及反应都在pH值3．0的情况,但仍有25％～40％的苋菜红牢固地结合在菌体上;pH值4．5生长,pH值6．0反应,导致反应启动滞后约4～6d,最终结果尚好。     

微胶囊固定化过氧化氢酶的制取及对H_2O_2的分解作用

以乙基纤维素为膜材,用溶液干燥法制取了微胶囊固定化过氧化氢酶,探讨了制取过程中明胶的加入对微胶囊产率及固定化过氧化氢酶活性的影响,同时论述了存放时间、温度以及环境ｐＨ值对微胶囊固定化过氧化氢酶稳定性的影响．深入研究了微胶囊固定化过氧化氢酶对Ｈ２Ｏ２的分解作用,获得了十分有意义的结果     

低粘度辛烯基琥珀酸淀粉钠作微胶囊壁材包埋柠檬油

以蜡质玉米淀粉为原料在优化条件下制备具有乳化能力的低粘度辛烯基琥珀酸淀粉钠(SSOS)。用Brabender粘度仪测定淀粉糊的粘度及其稳定性,发现酶处理前SSOS糊的粘度较蜡质玉米淀粉提高,但稳定性变化不大。研究发现低粘度SSOS微胶囊包埋柠檬油的百分率在57.4%至87.6%(w/w)之间,并取决于SSOS的葡萄糖值。在壁材与芯材的质量比大于3比2,葡萄糖值为12.8时,微胶囊包埋的产率和效率达到最高值。微胶囊在40℃下放置贮存3周后,其微胶囊化效率仅降低3%。通过扫描电镜观察,发现微胶囊为球形的未粘连的颗粒,有些颗粒的表面并不平整。研究结果表明一定葡萄糖值的低粘度SSOS作为微胶囊壁材具有很好的包埋效果。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.