The Breeding of a Pigment Mutant Strain of Steroid Hydroxylation Aspergillus Flavus by Low Energy Ion Implantation

In the process of the fermentation of steroid C11α-hydroxylgenation strain Aspergillus flavus AF-ANo208, a red pigment is derived, which will affect the isolation and purification of the target product. Low energy ion beam implantation is a new tool for breeding excellent mutant strains. In this study, the ion beam implantation experiments were performed by infusing two different ions： argon ion （Ar^＋） and nitrogen ion （N^＋）. The results showed that the optimal ion implantation was N^＋ with an optimum dose of 2.08- 1015 ions/cm^2, with which the mutant strain AF-ANm16 that produced no red pigment was obtained. The strain had high genetic stability and kept the strong capacity of C11α-hydroxylgenation, which could be utilized in industrial fermentation. The differences between the original strain and the mutant strain at a molecular level were analyzed by randomly amplified polymorphic DNA （RAPD）. The results indicated that the frequency of variation was 7.00%, which would establish the basis of application investigation into the breeding of pigment mutant strains by low energy ion implantation.

Photosynthetic Pigments Affected by Fertilizer Source in Four Brassica Vegetables

Effect of fertilizer source （mineral fertilizer or organic manure） on photosynthetic pigments leaves content of four brassica vegetables （Pak choi, Kohlrabi, Cauliflower and Cabbage） was tested. Among treatments, cauliflower fertilized with chicken manure had the highest content of chlorophyll a and b （10.08 and 9.37 μm·g^-1）, while, pak choi had the lowest values （2.00 and 2.44 μm·g^-1） in non-fertilized plants. These differences in chlorophyll a and b content may have a great impact on photosynthetic rate and activity. Total carotenoids and total xanthophylls （lutein, zeaxanthin, antheraxanthin and violaxanthin） were the highest in cauliflower while the lowest was in pakchoi, β-carotene, on the other hand, was the highest percentage of total carotenoids （65.7%） in pak choi while Kohlrabi had the lowest percent （57.4%）. This high percentage offl-carotene of total carotenoids may compensate for lower content of chlorophylls and assist for efficient light harvesting process. Lutein showed to be the major components of xanthophyll pigments brassica vegetables and ranged from 0.462μm·g^-1 in cabbage to 0.626μm·g^-1 in kohlrabi but not differed significantly which may refer to genetically controlled. However, lutein, antheraxanthin and zeaxanthin content were increased significantly by the application of chicken manure regardless ofbrassica vegetable type. Violaxanthin was only detected in pak choi and not affected by fertilizer source. It can be concluding from the increasing contents of total xanthophylls pigments that may increase photosynthetic efficiency through non-photochemical quenching process.

水性涂料

从水性涂料的物理特性、树脂合成方式、可水性化树脂种类几方面进行了分类说明 ,对组成水性涂料的颜填料、助剂也进行了总结 。

人诱导多能干细胞向视网膜色素上皮细胞分化及其应用于临床治疗的研究进展

视网膜色素上皮（retinal pigment epithelium,RPE）细胞是位于视网膜最外层的单层细胞,呈六角形,胞内富含黑色素。其功能主要包括：（1）吞噬感光细胞外节段;（2）代谢视紫红质;（3）参与构成血-视网膜屏障;（4）合成黑色素等。RPE细胞的功能丧失会引起多种视网膜疾病,如年龄相关黄斑变性、Stargardt病等[1]。RPE细胞已经到达终末分化阶段,损伤后无法再生,

辅色素对黄瑞木果实红色素稳定性的影响

测定纯化的黄瑞木果实红色素的光谱性质,通过添加不同的辅色剂来提高黄瑞木果实红色素的稳定性,研究在温度、光照等因素作用下对黄瑞木果实红色素的辅色作用,并选择辅色效果明显的辅色剂进行正交实验,确定最佳的辅色条件。

结构色油漆用于汽车外饰件的可行性分析

为探索结构色油漆用于汽车外饰件的可行性,研究了色粉包覆、色粉受潮和稳定剂加入对其耐光及耐热性能的影响。实验结果表明,结构色粉包覆后再制备色漆,可使涂层的耐光和耐热性能有所提升;色粉受潮会导致涂层的耐热性能下降;在油漆中加入适量的热稳定剂,有利于涂层耐热性能的提升。

The protective role of tacrine and donepezil in the retina of acetylcholinesterase knockout mice

AIM: To determine the effect of different concentrations of the acetylcholinesterase (AChE) inhibitors tacrine and donepezil on retinal protection in AChE(+/-) mice (AChE knockout mice) of various ages. METHODS: Cultured ARPE -19 cells were treated with hydrogen peroxide (H2O2) at concentrations of 0, 250, 500, 1000 and 2000 mu mol/L and protein levels were measured using Western blot. Intraperitoneal injections of tacrine and donepezil (0.1 mg/mL, 0.2 mg/mL and 0.4 mg/mL) were respectively given to AChE4- mice aged 2mo and 4mo and wild-type S129 mice for 7d; phosphate buffered saline (PBS) was administered to the control group. The mice were sacrificed after 30d by cardiac perfusion and retinal samples were taken. AChE(+/-) deficient mice were identified by polymerase chain reaction (PCR) analysis using specific genotyping protocols obtained from the Jackson Laboratory website. H&E staining, immunofluorescence and Western blot were performed to observe AChE protein expression changes in the retinal pigment epithelial (RPE) cell layer. RESULTS: Different concentrations of H2O2 induced AChE expression during RPE cell apoptosis. AChE(+/-) mice retina were thinner than those in wild -type mice (P< 0.05); the retinal structure was still intact at 2mo but became thinner with increasing age(P <0.05); furthermore, AChE'l- mice developed more slowly than wild-type mice (P <0.05). Increased concentrations of tacrine and donepezil did not significantly improve the protection of the retina function and morphology (P >0.05). CONCLUSION: in viva, tacrine and donepezil can inhibit the expression of AChE; the decrease of AChE expression in the retina is beneficial for the development of the retina.

(S)-3-aminopiperidine-2,6-dione is a biosynthetic intermediate of microbial blue pigment indigoidine

The biosynthetic investigations of microbial natural products continuously provide powerful biocatalysts for the preparation of valuable chemicals.Practical methods for preparing(S)-3-aminopiperidine-2,6-dione(2),the pharmacophore of thalidomide(1)and its analog drugs,are highly desired.To develop a biocatalyst for producing(S)-2,we dissected the domain functions of IdgS,which is responsible for the biosynthesis of indigoidine(3),a microbial blue pigment that consists of two 2-like moieties.Our data supported that the L-glutamine tethered to the indigoidine assembly line is first offloaded and cyclized by the thioesterase domain to form(S)-2,which is then dehydrogenated by the oxidation(Ox)domain and finally dimerized to yield 3.Based on this,we developed an IdgS-derived enzyme biocatalyst,IdgS-Ox^(*)R539A,for preparing enantiomerically pure(S)-2.As a proof of concept,one-pot chemoenzymatic synthesis of 1 was achieved by combining the biocatalytic and chemical approaches.

Intertextile Shanghai Apparel Fabrics——China International Trade Fair for Apparel Fabrics & Accessories S hanghai New International Exhibition Centre, Shanghai, China 20-23 October 2008

More than 2,500 suppliers from 30 countries have confirmed their attendance at Intertextile Shanghai Apparel Fabrics set for 20 - 23 October 2008 at the Shanghai New International Expo Centre, Shanghai China. The show features 10 halls with more than 115,000 sqm of trade space along with seminars and

Phytotoxicity in seven higher plant species exposed to di-n-butyl phthalate or bis （2-ethylhexyl） phthalate

We investigated phytotoxicity in seven plant species exposed to a range of concentrations （0- 500 mg· kg^-1 soil） of di-n-butyl phthalate （DnBP） or his （2- ethylhexyl） phthalate （DEHP）, two representative phthalate esters （PAEs） nominated by USEPA as priority pollutants and known environmental estrogens. We studied seed germination, root elongation, seedling growth, biomass （fresh weight, FW） and malondialdehyde （MDA） content of shoots and roots of wheat （Triticum aestivum L.）, alfalfa （Medicago sativa L.）, perennial ryegrass （Lolium perenne）, radish （Raphanus sativus L.）, cucumber （Cucumis sativus L.）, oat （Avena sativa） and onion （Allium cepa L.）, together with monitoring of plant pigment content （chlorophyll a, b and earotinoids） in alfalfa, radish and onion shoots. Root elongation, seedling growth and biomass of the test species were generally inhibited by DnBP but not by DEHP, indicating a lower level of phytotoxicity of DEHP than of DnBP. MDA contents of four species were promoted by PAE exposure, but not in alfalfa, ryegrass or onion shoots, indicating lower sensitivity of these three species to PAE pollutants. Plant pigment contents were clearly affected under the stress of both pollutants, implying the potential damage to the photosynthetic system of test plants, mainly by decreasing the content of chlorophyll a and b. Results of DnBP and DEHP phytotoxicity to the primary growth of test plants has provided information for the assessment of their environmental risk in the soil and also forms a basis for the further analysis of their toxic effects over the whole growth period of different plant species.

FLUORESCENCE CHARACTERISTICS OF PRESSURE DEPENDENCE IN C-PHYCOCYANIN FROM BLUE-GREEN ALGA Spirulina platensis

C-phycocyanin and allophycocyanin are chromoproteins with covalently attached linear tetrapyrroles functioned as accessory pigments in photosynthesis of blue-green and red algae. It is interesting that both C-phycocyanin and allophycocyanin possess chemically

CRYSTALLIZATION OF R-PHYCOERYTHRIN FOR X-RAY DIFFRACTION STUDIES

Phycoerythrin is one class of the photosynthetic accessory pigments in rokaryotic cyanobacteria (blue-green aloe) and eukaryotic rhodophyta (red algae). It plays a very important role in oxysenic photosynthesis. A detailed understanding of the effident physical mechanism of light absorption and energy transfer of photosynthesis must be based on the mo-

Diversity,community structure,and quantity of eukaryotic phytoplankton revealed using 18S rRNA and plastid 16S rRNA genes and pigment markers:a case study of the Pearl River Estuary

Understanding consistencies and discrepancies in characterizing diversity and quantity of phytoplankton is essential for better modeling ecosystem change.In this study,eukaryotic phytoplankton in the Pearl River Estuary,South China Sea were investigated using nuclear 18S rRNA and plastid 16S or 23S rRNA genes and pigment analysis.It was found that 18S abundance poorly explained the variations in total chlorophyll a(Chl-a).However,the ratios of log-transformed 18S abundance to Chl-a in the major phytoplankton groups were generally environment dependent,suggesting that the ratio has potential as an indicator of the physiological state of phytoplankton.The richness of 18S-based operational taxonomic units was positively correlated with the richness of 16S-based amplicon sequence variants of the whole phytoplankton community,but insignifcant or weak for individual phytoplankton groups.Overall,the 18S based,rather than the 16S based,community structure had a greater similarity to pigment-based estimations.Relative to the pigment data,the proportion of haptophytes in the 18S dataset,and diatoms and cryptophytes in the 16S dataset,were underestimated.This study highlights that 18S metabarcoding tends to refect biomass-based community organization of eukaryotic phytoplankton.Because there were lower copy numbers of plastid 16S than 18S per genome,metabarcoding of 16S probably approximates cell abundance-based community organization.Changes in biomass organization of the pigment-based community were sensitive to environmental changes.Taken together,multiple methodologies are recommended to be applied to more accurately profle the diversity and community composition of phytoplankton in natural ecosystems.

黑带食蚜蝇Episyrphus balteatus De Geer的复眼结构及其调光机制

【目的】观察研究黑带食蚜蝇Episyrphus balteatus De Geer成虫复眼形态、小眼结构和不同光暗条件对小眼结构的影响,以明确其光视觉的结构基础和调光机制。【方法】利用组织切片法和扫描电镜等技术。【结果】1.复眼位于头部两侧,正面观呈半球形,占据除额颜外大部分头部。雄虫与雌虫单个复眼分别有约7 180个、7 230个小眼。各小眼面呈整齐排列的规则六边形。2.小眼由角膜及伪晶锥组成的屈光器、不同水平面分布的8个小网膜细胞及其特化形成的离散型视杆、屏蔽色素细胞和基膜等组成。小眼自远端至近端由主色素细胞和12个附属色素细胞围绕。3.随光暗条件的改变小眼内的附属色素细胞色素和基细胞细胞核沿小眼纵轴移动。光适应时,附属色素细胞色素颗粒沿小眼纵轴均匀分布,基细胞细胞核位于基膜上方。暗适应时,附属色素细胞色素颗粒向伪晶锥近端压缩,基细胞细胞核亦向远端移动,到达视杆中段。【结论】黑带食蚜蝇复眼精密的小眼排列形式和内部结构均显示了其强大的生理功能;屏蔽色素颗粒的移动是其复眼适应外界光环境变化的重要机制。本试验为进一步探究黑带食蚜蝇视觉结构和光调节机制,以及与其飞行行为间的关系提供了一定的理论基础。