薏苡种子盾片上皮细胞的超微结构

应用电镜及组织化学方法观察了薏苡(Coic locryma-jobi L.)干种子盾片上皮细胞的超微结构及贮藏物质。贮藏物质为蛋白质体、脂肪体和淀粉粒。蛋白质体内含有拟晶体,为一层膜所包被。脂肪体外被有膜。细胞质中含有大量嵴较不发达的线粒体、丰富的核糖体、少量质体及内质网。核内染色质凝聚,核质电子密度亦较高。上述结构表明上皮细胞处于代谢不活跃状态,但大量的线粒体及丰富的核糖体又表明在种子萌发时,这些细胞具有高的代谢能力。     

如何瓶栽银耳

银耳俗称白木耳,它含有丰富的蛋白质、氨基酸、糖等物质,具有强身、补精、润肺和清热等作用,是一种很好的滋补品。     

使用微生物农药要防低温

<正>微生物农药活性成分主要由蛋白质晶体和有生命的芽孢组成,在低温条件下,芽孢在害虫体内繁殖速度缓慢,蛋白质晶体很难发挥作用达到最佳防治效果。     

鱼类眼睛晶体信息分析与应用研究进展

眼睛晶体作为鱼类的硬组织之一,具有结构稳定、耐腐蚀、易获取的特性,其含有大量的蛋白质,蕴含着丰富的化学信息,并在鱼类的年龄鉴定中得到了一定程度的应用。近年来,随着生物地球化学技术的不断创新与进步,鱼类眼睛晶体的微量元素、稳定同位素信息也越来越受到国内外学者的重视。本文将依据国内外学者的研究成果,从眼睛晶体的直径与重量、微结构、微量元素和稳定同位素等方面,对鱼类的年龄鉴定、栖息环境重建、摄食生态的追踪等方面的应用进行综述,并通过分析鱼类眼睛晶体的组成成分与生长模式,比较眼睛晶体与其他组织做稳定同位素分析的优势,着重归纳总结了眼睛晶体碳氮稳定同位素在鱼类生活史信息,尤其在摄食生态、栖息环境重建等方面的研究方法、应用现状及发展前景,为以后开展相关的研究提供参考。     

韭菜在养殖中的妙用

韭菜富含维生素A、B、C，还有糖类和蛋白质及抗生物质等，具有调味、杀菌、助阳等多种功效，在养殖中大有用处。     

森林病虫害防治施用苏云金杆菌应五看

<正>苏云金杆菌简称Bt,是目前研究最深入应用最广泛的微生物杀虫剂,属低毒杀虫剂,可用于直翅目、鞘翅目、鳞翅目等多种森林害虫防治。Bt的杀虫活性物质主要有两种,即晶体和孢子。晶体又叫原毒素。完整的晶体对昆虫不具活性,只有当晶体通过害     

挤压添加耐高温α-淀粉酶高粱辅料麦汁的蛋白质组分分析

麦汁中蛋白质的含量和分布在一定程度上决定了成品啤酒的蛋白质含量和分布。采用隆丁区分法和凝胶电泳技术分析挤压添加耐高温α-淀粉酶高粱辅料麦汁的蛋白质组分,预测啤酒蛋白质组分。测得麦汁中高相对分子质量含氮物质、中相对分子质量含氮物质和低相对分子质量含氮物质含量分别为16、14.6和52.5 mg/100 m L,相对分子质量主要集中在12~15、和36~42 k Da等3个区间。     

论铁观音茶的养生保健功能

铁观音含有芳香物质、蛋白质和氨基酸、糖类与脂类和多种矿物质元素等人体必须的营养成分,对人类健康具有重要作用。现代医学研究表明,除具有一般茶叶的保健功能外,铁观音还具有抗衰老、抗癌症、抗动脉硬化、防治糖尿病、减肥健美、防治龋齿、清热降火、敌烟醒酒等功效。     

孔雀痛风病的诊治

家禽痛风病是一种蛋白质营养代谢障碍引起的高血症.其病理特征为血液尿酸增高,尿酸盐在关节囊、内脏、气囊、肾小管等处沉积,机体长期嘌呤代谢障碍,血清中尿酸浓度升高使尿酸盐晶体沉着在结缔组织中.临床表现为运动迟缓,腿翅关节肿胀,厌食、腹泻、排白色石灰样粪便.本文描述的是一起过量添加高蛋白物质黄粉虫导致孔雀发生痛风病发生,及时采取防治措施,有效控制了病情的案例.现将诊治情况介绍如下.     

研究质膜蛋白质的一种银染方法

研究质膜蛋白质的一种银染方法刘风霞，薛刚（塔里木农垦大学，阿拉尔，８４３３００）有生命的细胞膜具有保持生长发育、运动与信息传递所需离子与代谢物质梯度的能力，而细胞膜中的蛋白质能够控制所需离子与代谢物质的移动。研究质膜蛋白质的组成，对了解细胞膜的结构和...     

Spherical crystallization: direct spherical agglomeration of salicylic Acid crystals during crystallization

Direct spherical agglomeration of salicylic acid crystals during crystallization is described. The needle-like salicylic acid crystals simultaneously form and agglomerate in a mixture of three partially miscible liquids, such as water, ethanol, and chloroform, with agitation. The agglomerates can be made directly into tablets because of their excellent flowability. Spherical crystallization could eliminate the usual separate agglomeration step after crystallization and may be adaptable to other pharmaceutical and chemical systems.     

Heterogeneous and epitaxial nucleation of protein crystals on mineral surfaces

Fifty different mineral samples were tested as potential heterogeneous or epitaxial nucleants for four commonly crystallized proteins. It was found, by conventional protein crystallization techniques, that for each protein there was a set of mineral substrates that promoted nucleation of crystals at lower critical levels of supersaturation than required for spontaneous growth. Numerous examples, involving all four proteins, were observed of modification of crystal habit and, in some cases, unit cell properties promoted by the presence of the mineral nucleants. In at least one case, the growth of lysozyme on the mineral apophyllite, it was shown by lattice analysis and x-ray diffraction that the nucleation and growth of the protein crystal on the mineral was likely to involve a direct lattice match.     

Direct fabrication of large micropatterned single crystals

Micropatterning of single crystals for technological applications is a complex, multistep process. Nature provides alternative fabrication strategies, when crystals with exquisite micro-ornamentation directly develop within preorganized frameworks. We report a bio-inspired approach to growing large micropatterned single crystals. Micropatterned templates organically modified to induce the formation of metastable amorphous calcium carbonate were imprinted with calcite nucleation sites. The template-directed deposition and crystallization of the amorphous phase resulted in the fabrication of millimeter-sized single calcite crystals with sub-10-micron patterns and controlled crystallographic orientation. We suggest that in addition to regulating the shape, micropatterned frameworks act as sites for stress and impurity release during the amorphous-to-crystalline transition. The proposed mechanisms may have direct biological relevance and broad implications in materials synthesis.     

结晶法提取乳清中乳糖工艺的研究

本试验以生产鲜奶干酪素时排放的乳清为原料,经过中和去除乳清蛋白后浓缩、结晶得到粗制乳糖.结合单因素试验确定pH值、保温时间、结晶浓度为影响乳糖提取的主要因素,结合单因素及正交试验确定最佳工艺参数为:中和pH值6.8、保温时间40 min、浓缩糖度50 B啨.所得制品的感官、乳糖含量、水分、灰分氯化物等指标均符合QB/T3778-1999一级品标准.     

The crystallization of ultralong normal paraffins: the onset of chain folding

The nature of chain folding in polymers and the determination of the chain length at which folding occurs have been central questions in polymer science. The study of the formation of lamellar polymer crystals through chain folding has received a new impetus as a result of the recent synthesis of normal alkanes of strictly uniform chain lengths up to C(390) H(782). Chain folding is found in all such paraffins starting with C(150)H(302). As with polyethylenes obtained by conventional polymerization, the fold length in the normal alkanes varies with crystallization temperature, but it is always an integral reciprocal of the full chain length. This behavior indicates that the methyl end groups are located at the lamellar surface and that the fold itself must be sharp and adjacently reentrant.     

Mechanisms of Porphyroblast Crystallization: Results from High-Resolution Computed X-ray Tomography

Quantitative three-dimensional analysis of rock textures is now possible with the use of high-resolution computed x-ray tomography. When applied to metamorphic rocks, this technique provides data on the sizes and positions of minerals that allow mechanisms of porphyroblast crystallization to be identified. Statistical analysis of the sizes and spatial disposition of thousands of garnet crystals in three regionally metamorphosed rocks with diverse mineralogies, in conjunction with simple numerical models for crystallization, reveals in all cases the dominance of crystallization mechanisms whose kinetics are governed by rates of intergranular diffusion of nutrients.     

植物冷激蛋白的研究概况

在植物体内合成的特定低温应激蛋白中,多数已经被鉴定。近年来,研究的焦点主要集中在几种特殊类型的冷激蛋白,其中,植物抗冻蛋白保护细胞免受冰晶破坏,分子伴侣和脱水蛋白在冷胁迫期间保护细胞大分子不受损伤,线粒体内解偶联蛋白的氧化和磷酸化过程,可以使植物保持高于0℃一段时间,为随后适应低于0℃的环境做充分的准备。     

趋磁细菌磁小体合成相关蛋白的研究进展

趋磁细菌是一类能够沿着磁场方向运动的革兰氏阴性细菌的总称,其最显著的特征是能够在胞内合成特殊的原核细胞器——磁小体。磁小体是具有外膜包被、纳米级、在胞内成链状排列的Fe3O4或Fe3S4磁性颗粒,并且具有专属的形态、大小和排列。正是因为磁小体的这些特性使不同领域的科研工作者开发着趋磁细菌的应用。另外,磁小体可以作为生物矿化和原核生物形成膜细胞器的理想模型。趋磁细菌磁小体合成相关蛋白在磁小体囊泡的形成、铁的转运、成晶的控制以及胞内磁性颗粒的排列等过程中发挥作用。文中重点介绍了近年来发现的和趋磁细菌磁小体合成相关的蛋白,并对未来磁小体蛋白的研究进行了展望。     

Reactions of organ crystals with gases

Although reactions of molecular crystals are much more widespread than has been generally appreciated (53), the great sensitivity of their rates to seemingly trivial changes in molecular structure clearly provides a major stumbling block to the general utilization of such processes. A key to understanding the effects of structural changes has been provided by the demonstration of anisotropy of such reactions discussed in this article. It is recognized, however, that many factors in addition to those aspects of the crystal structure utilized in the discussion above may play a part in determining reactivity of crystalline solids with gases. The recent ready availability of crystal structure data for molecular crystals should lead to a more rapid development of the principles governing the packing of such crystals and their reactivity. The resulting control of such reactions should not only provide the means of causing them when they are desired, as, for example, for synthesis, but also the means of preventing them when they are to be avoided, as in the stabilization of pharmaceuticals. Finally, it appears that we have only just begun to exploit the potential reaction specificity and the exciting possibilities resulting from the unique symmetry properties of the crystalline state.     

溶剂置换结晶法制备甘露糖的研究

[目的]介绍一种制备高纯度D-甘露糖晶体的方法.[方法]以甘露糖、葡萄糖混合溶液为原料,有机溶剂置换结晶法得到粗晶产品,乙醇浸泡洗涤晶体得到纯度在99％以上的甘露糖晶体.通过比较筛选适合的置换有机溶剂,在此基础上,考察了乙醇的用量、乙醇浸泡洗涤的时间对高纯度D-甘露糖晶体得率的影响.[结果]试验确定了置换溶剂乙醇的用量以及乙醇浸泡洗涤的时间：以乙醇为结晶置换溶剂,最佳用量为60％,以乙醇为洗涤溶剂,最佳浸泡洗涤时间为20～30 min,最终甘露糖纯度达到99％以上,收率60％以上.[结论]溶剂置换结晶法制备高纯度D-甘露糖晶体的结晶时间短、能耗低、操作简单.