组织工程的临床研究——组织工程连载之五

组织工程研究涉及的临床科室包括骨科、普外科、五官科、康复医学科、泌尿科、口腔颌面外科、神经外科、整形外科、胸外科、眼科、肝胆外科、血管外科;涉及的组织器官有:神经组织、肝脏组织、角膜组织、膀胱组织、血液、韧带、耳朵、生殖道、手、脂肪、乳房、心脏、肾脏、胰腺、管状组织(用于建造肠管、食管、气管、血管、肾和尿道等)等.其中皮肤组织、软骨组织、骨组织等的研究应用较为成熟.从最初工程化组织或器官的立项研究到最终批准临床应用,这是一个漫长的过程,需要众多不同学科的科研人员共同努力.随着基础研究和临床应用的深入发展,现代组织工程正在成为治疗组织、器官衰竭的有效疗法和辅助手段.     

实验室到大生产——生物工程产业化解决之道

<正>国家重点新产品国家火炬计划国家高新技术示范企业东方生工发酵装备业的领跑者见证实力体现价值高等院校北京大学、清华大学、首都师范大学、北京科技大学、北京联合大学、中国农业大学、天津轻工业学院、天津医科大学、哈尔滨工业大学、八一农垦大学、东北大学、江南大学、南京农业大学、南京师范大学、中国矿业大学、上海交通大学、华东师范大学、浙江大学、浙江工业大学、山西大学、厦门大学、集美大学、福建师范大学、福建农林大学、山东大学、山东海洋大学、青岛海洋大学、青岛大学、烟台大学、中山大学、深圳大学、华南理工大学、广西大学、西北大学、西北农林科技大学、云南大学、湖南大学、合肥工业大学、东南大学、南京林业大学……     

《植物学报》第七届编委会第一次会议纪要

<正>《植物学报》第七届编委会第一次会议于2015年1月23日在中国农业科学院深圳农业基因组研究所隆重召开。主编种康,学术咨询委员武维华和薛勇彪,副主编王台、钱前、王小菁、左建儒、顾红雅、姜里文、白永飞、杨淑华、孔宏智、陈凡和萧浪涛,责任编委(以姓氏拼音为序)安黎哲、戴绍军、戴思兰、丁勇、丁兆军、冯献忠、傅缨、葛磊、何军贤、侯岁稳、李明军、李韶山、李思锋、李毅、刘宝辉、麻密、毛同林、孟征、秦     

《生命科学》投稿须知

<正>1投稿范围细胞生物学与发育生物学、免疫学、遗传学、生物化学与分子生物学、生物医学工程学、药物学与药理学、动物学、植物学、微生物学、林学、农学、生态学、生物物理学、神经科学、畜牧兽医学与水产     

《植物学报》第六届编委会第一次会议纪要

《植物学报》第六届编委会第一次会议于2009年6月11日在河南师范大学生命科学学院召开。主编种康,副主编杨维才、瞿礼嘉、王台、王小菁、袁明、蒋高明、钱前,责任编委安黎哲、陈凡、戴思兰、何奕昆、黄建辉、孔宏智、李思锋、林宏辉、刘宝、麻密、孟征、任东涛、尚富德、宋纯鹏、谭保才、田长恩、田世平、王慧中、王英典、吴鸿、萧浪涛、徐云远、杨淑华、张立新、张治礼、赵桂仿和郑海雷以及编辑部全体成员参加了会议。     

镇江东方生物工程设备技术公司

<正>国家重点新产品国家火炬计划国家高新技术示范企业东方生工发酵装备业的领跑者实验室到大生产——生物工程产业化解决之道见证实力体现价值高等院校:北京大学、清华大学、首都师范大学、北京科技大学、北京联合大学、中国农业大学、天津轻工业学院、天津医科大学、哈尔滨工业大学、八一农垦大学、东北大学、江南大学、南京农业大学、南京师范大学、中国矿业大学、上海交通大学、华东师范大学、浙江大学、浙江工业大学、山西大学、厦门大学、集美大学、福建师范大学、福建农林大学、山东大学、山东海洋大学、青岛海洋大学、青岛大学、烟台大学、中山大学、     

《生命科学》投稿须知

<正>投稿范围细胞生物学与发育生物学、免疫学、遗传学、生物化学与分子生物学、生物医学工程学、药物学与药理学、动物学、植物学、微生物学、林学、农学、生态学、生物物理学、神经科学、畜牧兽医学与水产学、生理学与病理学、预防医学、临床医学基础学科等与生命科学相关的研究领域。只刊登综述与评述类文章。     

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CN101720830A 一种生物多糖药茶饮料 本发明涉及一种生物多糖药茶饮料制备。该饮料含有绿茶、山楂、板蓝根、金银花、香菇、茯苓、银耳、甘草、黄豆、维生素（C、B1、B2、B6、B12）、叶酸。经挑选、清洗、破碎、湿润、接种、培养、煎煮、萃取、过滤、调配、灌装、杀菌等工艺步骤而制成。     

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1．《生物学杂志》是生命科学的综合性学术期刊,刊登动物、植物、微生物及其生理、生化、遗传、生物技术、生物工程、分子生物学、生物教学等方面的文章。主要栏目有：综述与专论、研究报告、开发与应用、技术方法、教学研究、科普及其它等。反映国内外最新研究成果的论文、国家自然科学基金资助的论文、获省级以上科研成果的论文将优先发表。 ,     

植物组织培养系列：试剂、消耗品专营

1激素类 国产及进口6-BA、6．KT、CPA、BPA、ABA、IAA、IBA、IPA、NAA、TIBA、BNOA、GA3、2,4-D、CPPU、异戊烯基腺嘌呤（2iP）、苯基噻二：唑基脲（TDZ）、腺嘌呤、腺嘌呤硫酸盐、毒莠定、反-玉米素、（&#177;）Jasmonicacid、Dicamba等。可办理国外Sigma、Fluka、Aldrich、Amrcsco、Sanland、Merck、Gibco／brl、Fisher等公司产品专项订货,到货快,价格合理。     

A new method for the quantification of chitin and chitosan in edible mushrooms

Along with β-glucans, chitin is the dominant component of the fungal cell wall. Chitosan, the deacetylated form of chitin, has found quite a number of biomedical and biotechnological applications recently. Mushroom chitin could be an important source for chitosan production. A direct determination of chitin and chitosan in mushrooms is of expedient interest. In this paper, a new method for the quantification of chitin and chitosan is described. This method is based on the specific reaction between polyiodide anions and chitosan and on measuring the optical density of the insoluble polyiodide–chitosan complex. After deacetylation, chitin can also be quantified. The specificity of the reaction is used to quantify the polymers in the presence of complex matrices. With this new spot assay, the chitin content of mycelia and fruiting bodies from several basidiomycetes and an ascomycete were analysed. The presented method could also be used for the determination in other samples as well. The chitin content of the analysed species varies between 0.4 and 9.8 g chitin per 100 g of dry mass. Chitosan could not be detected in our mushroom samples, indicating that the glucosamine units are mostly acetylated.     

Chitin and chitosan biopolymer production from the Iranian medicinal fungus Ganoderma lucidum: Optimization and characterization

Abstract

Chitin and chitosan with unique properties and numerous applications can be produced from fungus. The production of chitin and chitosan from the mycelia of an Iranian Ganoderma lucidum was studied to improve cell growth and chitin productivity. Inoculum size and initial pH as two effective variables on the growth of G. lucidum and chitin production were optimized using response surface method (RSM) by central composite design (CCD). The results verified the significant effect of these two variables on the cell growth and chitin production. In optimum conditions, including pH?=?5.7 and inoculum size of 7.4%, the cell dry weight was 5.91?g/L and the amount of chitin production was 1.08?g/L with the productivity of 0.083?g/(L day). The produced chitin and chitosan were characterized using XRD and FTIR. Moreover, the antibacterial activity of the produced chitosan was investigated and compared with the commercial chitosan. The results showed that the produced chitin and chitosan had suitable quality and the Iranian G. lucidum would be a great source for safe and high-quality chitin and chitosan production.     

Chitosan, the deacetylated form of chitin, is necessary for cell wall integrity in Cryptococcus neoformans

Cryptococcus neoformans is an opportunistic fungal pathogen that causes cryptococcal meningoencephalitis, particularly in immunocompromised patients. The fungal cell wall is an excellent target for antifungal therapies as it is an essential organelle that provides cell structure and integrity, it is needed for the localization or attachment of known virulence factors, including the polysaccharide capsule, melanin, and phospholipase, and it is critical for host-pathogen interactions. In C. neoformans, chitosan produced by the enzymatic removal of acetyl groups from nascent chitin polymers has been implicated as an important component of the vegetative cell wall. In this study, we identify four putative chitin/polysaccharide deacetylases in C. neoformans. We have demonstrated that three of these deacetylases, Cda1, Cda2, and Cda3, can account for all of the chitosan produced during vegetative growth in culture, but the function for one, Fpd1, remains undetermined. The data suggest a model for chitosan production in vegetatively growing C. neoformans where the three chitin deacetylases convert chitin generated by the chitin synthase Chs3 into chitosan. Utilizing a collection of chitin/polysaccharide deacetylase deletion strains, we determined that during vegetative growth, chitosan helps to maintain cell integrity and aids in bud separation. Additionally, chitosan is necessary for maintaining normal capsule width and the lack of chitosan results in a "leaky melanin" phenotype. Our analysis indicates that chitin deacetylases and the chitosan made by them may prove to be excellent antifungal targets.     

A chitin synthase and its regulator protein are critical for chitosan production and growth of the fungal pathogen Cryptococcus neoformans

Chitin is an essential component of the cell wall of many fungi. Chitin also can be enzymatically deacetylated to chitosan, a more flexible and soluble polymer. Cryptococcus neoformans is a fungal pathogen that causes cryptococcal meningoencephalitis, particularly in immunocompromised patients. In this work, we show that both chitin and chitosan are present in the cell wall of vegetatively growing C. neoformans yeast cells and that the levels of both rise dramatically as cells grow to higher density in liquid culture. C. neoformans has eight putative chitin synthases, and strains with any one chitin synthase deleted are viable at 30 degrees C. In addition, C. neoformans genes encode three putative regulator proteins, which are homologs of Saccharomyces cerevisiae Skt5p. None of these three is essential for viability. However, one of the chitin synthases (Chs3) and one of the regulators (Csr2) are important for growth. Cells with deletions in either CHS3 or CSR2 have several shared phenotypes, including sensitivity to growth at 37 degrees C. The similarity of their phenotypes also suggests that Csr2 specifically regulates chitin synthesis by Chs3. Lastly, both chs3Delta and the csr2Delta mutants are defective in chitosan production, predicting that Chs3-Csr2 complex with chitin deacetylases for conversion of chitin to chitosan. These data suggest that chitin synthesis could be an excellent antifungal target.     

Lime treatment of shrimp head waste for the generation of highly digestible animal feed

In addition to approximately 20% ash, shrimp processing by-products contain 64% protein and chitin, both of which can be used to generate several valuable products. Chitin and chitosan production is currently based on several crustacean wastes, and at the present time the protein fraction is not being used. This paper describes the thermo-chemical treatment of shrimp processing wastes with lime to generate a protein-rich material with a well-balanced amino acid content that can be used as a monogastric animal feed supplement. The residual solid, rich in calcium carbonate and chitin, can still be used to generate chitin and chitosan through well-established processes.     

The influence of supplemental components in nutrient medium on chitosan formation by the fungus Absidia orchidis

Chitosan, a derivative of chitin, is a natural component of some fungus cell walls. It is formed by the complex action of chitin synthase and chitin deacetylase. The in vitro activity of these two enzymes is known to be influenced by several factors. We investigated the influence of ferrous ions, manganese ions, cobalt ions, trypsin, and chitin, as individual supplements to the nutrient medium, on the in vivo activity of chitin synthase and chitin deacetylase to form chitosan in the fungus Absidia orchidis. Manganese and ferrous ions gave the most significant results. These ions increase chitosan yields through an increase in biomass production rather than an increase of chitosan content in cell walls. Manganese and ferrous ions lowered the activity of chitin deacetylase; however, their influence on the activity of chitin synthase was more complex. The effects of trypsin and chitin on biomass and cell wall chitosan content were negligible, while cobalt ions completely inhibited the growth of fungi.     

壳寡糖对辣椒种子萌发及幼苗抗氧化酶活性影响研究

壳寡糖是甲壳素的重要衍生物,具有良好的生物学活性,可调节植物生长,使农作物和水果蔬菜增产丰收,因而在农业上的应用日渐增多,在农业上的应用,包括促进种子萌发和植物生长。本文选取辣椒种子为研究对象,探讨了不同浓度壳寡糖对辣椒种子萌发的影响,研究结果表明一定浓度的壳寡糖可以促进种子萌发,以0.10mg/L浓度的壳寡糖效果最显著;不同浓度壳寡糖浸种处理能激活辣椒幼苗抗氧化酶活性。     

Comparative studies on the adsorption of Cr(VI) ions on to various sorbents

The adsorption of Cr(VI) ions onto various sorbents (chitin, chitosan, ion exchangers; Purolite CT-275 (Purolite I), Purolite MN-500 (Purolite II) and Amberlite XAD-7) was investigated. Batch adsorption experiments were carried out as a function of pH, agitation period and concentration of Cr(VI) ions. The optimum pH for Cr(VI) adsorption was found as 3.0 for chitin and chitosan. The Cr(VI) uptake by ion exchangers was not very sensitive to changes in the pH of the adsorption medium. The maximum chromium sorption occurred at approximately 50 min for chitin, 40 min for Purolite II and 30 min for chitosan, Purolite I and Amberlite XAD-7. The suitability of the Freundlich and Langmuir adsorption models were also investigated for each chromium-sorbent system. Adsorption isothermal data could be accurately interpreted by the Langmuir equation for chitosan, chitin, Purolite I and Purolite II and by the Freundlich equation for chitosan, chitin and Amberlite XAD-7. The chromium(VI) ions could be removed from the sorbents rapidly by treatment with an aqueous EDTA solution and at the same time the sorbent regenerated and also could be used again to adsorb by heavy metal ions. The results showed that, chitosan, which is a readily available, economic sorbent, was found suitable for removing chromium from aqueous solution.     

Preparative methods of phosphorylated chitin and chitosan--an overview

Biomaterials such as chitin, chitosan and their derivatives have a significant and rapid development in recent years. Chitin and chitosan have become cynosure of all party because of an unusual combination of biological activities plus mechanical and physical properties. However, the applications of chitin and chitosan are limited due to its insolubility in most of the solvents. The chemical modification of chitin and chitosan are keen interest because of these modifications would not change the fundamental skeleton of chitin and chitosan but would keep the original physicochemical and biochemical properties. They would also bring new or improved properties. The chemical modification of chitin and chitosan by phosphorylation is expected to be biocompatible and is able to promote tissue regeneration. In view of rapidly growing interest in chitin and chitosan and their chemical modified derivatives, we are here focusing the recent developments on preparation of phosphorylated chitin and chitosan in different methods.     

Chitin deacetylases: new, versatile tools in biotechnology

Chitin deacetylases have been identified in several fungi and insects. They catalyse the hydrolysis of N-acetamido bonds of chitin, converting it to chitosan. Chitosans, which are produced by a harsh thermochemical procedure, have several applications in areas such as biomedicine, food ingredients, cosmetics and pharmaceuticals. The use of chitin deacetylases for the conversion of chitin to chitosan, in contrast to the presently used chemical procedure, offers the possibility of a controlled, non-degradable process, resulting in the production of novel, well-defined chitosan oligomers and polymers.