Chitosan—A versatile semi-synthetic polymer in biomedical applications

This review outlines the new developments on chitosan-based bioapplications. Over the last decade, functional biomaterials research has developed new drug delivery systems and improved scaffolds for regenerative medicine that is currently one of the most rapidly growing fields in the life sciences. The aim is to restore or replace damaged body parts or lost organs by transplanting supportive scaffolds with appropriate cells that in combination with biomolecules generate new tissue. This is a highly interdisciplinary field that encompasses polymer synthesis and modification, cell culturing, gene therapy, stem cell research, therapeutic cloning and tissue engineering. In this regard, chitosan, as a biopolymer derived macromolecular compound, has a major involvement. Chitosan is a polyelectrolyte with reactive functional groups, gel-forming capability, high adsorption capacity and biodegradability. In addition, it is innately biocompatible and non-toxic to living tissues as well as having antibacterial, antifungal and antitumor activity. These features highlight the suitability and extensive applications that chitosan has in medicine. Micro/nanoparticles and hydrogels are widely used in the design of chitosan-based therapeuticsystems. The chemical structure and relevant biological properties of chitosan for regenerative medicine have been summarized as well as the methods for the preparation of controlled drug release devices and their applications.     

Design and synthesis of conformationally constrained cyclophilin inhibitors showing a cyclosporin-A phenotype in C. elegans

Cyclophilin A (CypA) is a member of the immunophilin family of proteins and receptor for the immunosuppressant drug cyclosporin A (CsA). Here we describe the design and synthesis of a new class of small-molecule inhibitors for CypA that are based upon a dimedone template. Electrospray mass spectrometry is utilised as an initial screen to quantify the protein affinity of the ligands. Active inhibitors and fluorescently labelled derivatives are then used as chemical probes for investigating the biological role of cyclophilins in the nematode Caenorhabditis elegans.     

三种双苯并咪唑型荧光增白剂的合成及荧光性能研究

分别以马来酸、对苯二甲酸、酒石酸和邻苯二胺为起始原料,合成了3种双苯并咪唑型荧光增白剂1,2-二(2-苯并咪唑基)乙烯(a)1,4,-二(2-苯并咪唑基)苯(b)和1,2-二(2-苯并咪唑基)-1,2-乙二醇(c)。考察了微波功率、反应时间、原料配比等反应条件对微波辅助合成(a)和(b)收率的影响。采用紫外吸收及荧光发射光谱研究了产物的荧光性能,结果发现,产物在日光紫外波段均有较强的紫外吸收(λmax分别为361,347,343 nm),在各自最佳激发波长下激发均有较强的蓝紫色荧光(最大荧光发射波长分别为416,3944,17 nm),说明它们在荧光增白剂方面具有很好的应用前景。     

紧凑型荧光灯的输入电流谐波

通过实测数据说明紧凑型荧光灯的输入电流谐波的数据分布情况。计算三相四线供电时的中线电流，根据电网允许注入的谐波电流值确定选用紧凑型荧光灯的数量，保证安全用电。     

1-苯并噻唑基-3,5-二苯基吡唑啉衍生物的合成与荧光性

设计和合成了7个新型苯并噻唑基-吡唑啉类化合物，通过元素分析和红外光谱检测，确定了化合物的结构，荧光检测结果表明它们的荧光强度为36．1-69.2，荧光强度的大小与衍生物中的取代基有关，溴和甲氧基取代衍生物具有较高的荧光性。     

NMR在二苯乙烯型荧光增白剂结构鉴定中的应用

二苯乙烯类荧光增白剂的NMR测试中,烯键氢都是以单峰形式出现在δ8.0ppm-8.1ppm处,烯键邻位氢向低场偏移0.2ppm-0.6ppm,芳环上的氢有一定溶剂效应,使其产生0.2ppm的高场偏移。在7.68ppm-7.84ppm、7.26ppm-7.29ppm、6.93ppm-6.94ppm处出现这类化合物的特征峰。通过低场δ.>8.5ppm处的活泼氢的数目可以判断苯胺取代基种类;在C—NMR中可根据δ 44ppm-66ppm不同化学位移来确定取代基的种类。     

荧光探针法研究结构明确的BzO-PDMAEMA均聚物水溶液性质

通过氧阴离子聚合合成了一系列不同相对分子质量的结构明确的BzO—PDMAEMA，用芘作为荧光探针研究了BzO—PDMAEMA在水溶液中的胶束化行为，发现CMC值与用表面张力法测得的结果相一致，即随BzO—PDMAEMA相对分子质量的增加而减小，但荧光探针法测得的CMC值稍大；LCST值则随相对分子质量的增加而增加。     

6-甲氧基-2-[5-甲氧基-2-(4-甲基苯磺酰氨基)]苯基-4-苯并噁嗪酮的合成及荧光性能

以3 羟基苯甲醛为原料,通过硝化、醚化、氧化、还原等过程,找出制备中间体5 甲氧基邻氨基苯甲酸的较佳条件。在吡啶中,5 甲氧基邻氨基苯甲酸和对甲苯磺酰氯反应,得到荧光发射波长为590nm的荧光剂6 甲氧基 2 [5 甲氧基 2 (4 甲苯磺酰氨基)]苯基 4 苯并口恶嗪酮,并配制油墨:黏度54 3Pa·s,黏性4 71,细度11μm。适应于轮转胶印印刷。     

荧光灯的汞污染及其防治

分析荧光灯的汞污染及其危害 ,提出防治汞污染的建议措施     

Eu~(3+)掺杂Y_2O_3-Al_2O_3-SiO_2玻璃的制备与荧光性能研究

采用高温熔融法制备了Eu3+掺杂Y2O3-Al2O3-SiO2荧光玻璃,探讨了成分对该体系玻璃形成能力的影响,并对不同Eu3+掺杂浓度下的荧光性能进行了研究.结果表明,熔融温度为1500℃条件下,SiO2含量对该体系的玻璃形成能力影响明显,Y/Al摩尔比为3/5时,SiO2含量在52%—68%(摩尔分数)范围内时可以获得玻璃.掺杂Eu3+的Y2O3-Al2O3-SiO2玻璃具有荧光性能,在395nm波长激发下,在588 nm和614 nm处出现明显的发射峰.随着Eu3+掺杂浓度的增加,该荧光玻璃的发射波长不变,但发射强度有所变化;当Eu3+掺杂浓度为1.5%(摩尔分数)时,特征发射峰强度最大.