摘要：
The thermal effects of the necking in fiber drawing, with respect to the change of microstructure and deformation thermodynamics, have been studied in this paper. The microstructure change before and after necking was characterized by differential scanning calorimeter, revealing the significant variations of crystallinity of polyester (PET) fiber. According to the thermal effect feature during the fiber cold-drawing process, deformation thermodynamics is established to analyze the necking mechanism. Internal energy increase in polypropylene fiber may be caused by melting of crystal or stored elastic strain energy, while the internal energy of PET fiber decreases with time, probably caused by the induced crystallization.
作者：
Guo Wenlu;Yuan Liyong;Nie Changming;Wei-Qun Shi
作者机构：
[Guo Wenlu; Yuan Liyong; Nie Changming; Wei-Qun Shi] Institute of High Energy Physics,Chinese Academy of Sciences;[Guo Wenlu; Yuan Liyong; Nie Changming; Wei-Qun Shi] School of Chemistry and Chemical Engineering,University of South China
会议名称：
中国化学会第九届全国无机化学学术会议
会议时间：
2015-01-01
会议地点：
中国江西南昌
会议论文集名称：
中国化学会第九届全国无机化学学术会议论文集-L能源材料化学
摘要：
Uranium, as a predominant fuel ingredient for most nuclear reactors, is the key element in nuclear fuel cycle. Moreover, its chemical and physiological toxicity can be never negligible when it is open
摘要：
Meningococcal disease is a fatal illness of sudden onset caused by Neisseria meningitides. Meningococcal capsular polysaccharide (CPS) is a major virulence factor that generally does not induce immunological memory. Conjugation with a carrier protein can significantly increase the immunogenicity of CPS and induce immunological memory. However, it is highly desired to optimize the CPS-specific immunogenicity of the conjugate vaccine. Although adjuvant has been widely used to improve the immunogenicity of antigens, co-administration and conjugation of adjuvant with the conjugate vaccine has rarely been investigated. As a stimulator of humoral and cellular immunity, beta-glucan can activate macrophages and trigger intracellular processes to secrete cytokines initiating inflammatory reactions. In the present study, a conjugate vaccine (CPS-TT) was generated by conjugation of tetanus toxoid (TT) with meningococcal group Y CPS. CPS-TT was further conjugated with beta-glucan to generate CPS-TT-G. Immunization with CPS-TT-G led to an 8.2-fold increase in the CPS-specific IgG titers as compared with CPS-TT. Presumably, conjugation of beta-glucan ensured the two components to simultaneously reach the antigen presenting cells and stimulate the immune response. In contrast, co-administration of beta-glucan suppressed the CPS-specific immunogenicity of CPS-TT. Thus, conjugation of beta-glucan is an effective strategy to markedly improve the CPS-specific immunogenicity of the conjugate vaccine. (C) 2015 Elsevier Ltd. All rights reserved.
摘要：
Neisseria meningitidis can cause severe and fulminant diseases such as meningitis. Meningococcal capsular polysaccharide (PS) is a key virulence determinant that is not able to induce immunological memory. Conjugation of PS to a carrier protein can significantly increase the immunogenicity of PS and induce immunological memory. Due to the classically described carrier-induced epitopic suppression (CIES) mechanisms, a strong immune response against the carrier protein could suppress the immune response to PS after coadministration of free carrier protein with the conjugate vaccine. However, it was not clear whether suppressing Or enhancing the protein-specific immunogenicity could improve the PS-specific immunogenicity of the conjugate vaccine. Thus, moderate PEGylation, extensive PEGylation and oligomerization were used to regulate the immunogenicity of tetanus toxoid (TT) in the conjugate vaccine (PS-TT). Moderate PEGylation led to a 2.7-fold increase in the PS-specific IgG titers elicited by PS-IT. In contrast, extensive PEGylation and oligomerization of TT led to 1.4-fold and 1.6-fold decrease in the PS-specific IgG titers elicited by PS-TT, respectively. The PS-specific immunogenicity of PS-TT can be increased by moderate PEGylation through mild suppression of the TT-specific immunogenicity. The PS-specific immunogenicity of PS-TT was decreased through significant suppression or enhancement of the TT-specific immunogenicity. Thus, our study contributes to understand the CIES mechanisms and improve the PS-specific immunogenicity of a meningococcal PS conjugate vaccine. (C) 2015 Elsevier Ltd. All rights reserved.
作者机构：
[Lin Ying-Wu; Sun Mei-Hui; Nie Chang-Ming; Du Ke-Jie] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Wen Ge-bo; Lin Ying-Wu] Univ South China, Lab Prot Struct & Funct, Hengyang 421001, Peoples R China.
通讯机构：
[Lin Ying-Wu] U;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
摘要：
Understanding uranium-protein interaction is important for revealing the mechanism of uranyl ion (UO_2~(2+)) toxicity. In this study, we investigated the interaction between UO_2~(2+) and a quadruple mutant of cytochrome b5 (E44/48/56A/D60A cyt b_5, namely 4A cyt b_5) by spectroscopic approaches. The four mutated negatively-charged surface residues of cyt b_5 have been considered to be the interactive sites with cytochrome c (cyt c). Also, we studied the interaction between UO_1~(2+) and the protein-protein complex of 4A cyt b5-cyt c. The results were compared to the interaction between UO_2~(2+) and cyt b5, and the interaction between cyt c and cyt b_5-cyt c complex, from previous studies. It was found that the interaction of UO_2~(2+)-cyt b_5, i.e., uranyl ion binding to cyt b_5 surface at Glu37 and Glu43 as previously proposed by molecular modeling, is regulated by both surface mutations of cyt b_5 and its interacting protein partner cyt c. These provide valuable information on metal-protein-protein interactions and clues for understanding the mechanism of uranyl toxicity.
