顺丁烯二酸(酐)及其衍生物在皮革化学品合成中的应用探讨

对顺丁烯二酸（酐）及其衍生物在皮革化学品合成中的使用方法和发展过程进行了归纳和总结，分析和比较了顺酐及其衍生物在聚合物复鞣剂、磺基琥珀酸化加脂剂以及两亲结构复鞣加脂剂等几类产品分子结构中的作用及其特点，对相关的主要化学反应进行了分析和描述。并从绿色化学的角度对顺酐相关化学反应的优点进行了分析。     

Tailored biodegradable films via extrusion blow molding using PBS,PBAT, and TPS

Research to replace synthetic polymers with biodegradable polymers is on the rise because common plastics have generated serious ecosystem problems. Films with thermoplastic starch (TPS), poly(butylene succinate) (PBS), poly(butylene adipate-co-butylene terephthalate (PBAT), and citric acid (CA) were produced by blown extrusion. They were characterized by blow-up ratio (BUR), water vapor permeability (WVP), soluble ratio (SR), water sorption isotherm, and thermogravimetric (TG) techniques. Films were uniform and showed BUR > 205%. The different proportions of PBS and PBAT significantly influenced the WVP of the films. All samples had WVP with an order of magnitude similar to other blends with high starch content (10⁻⁶ g m⁻¹ day⁻¹ Pa⁻¹). CA efficiently decreased the WVP of the PBS/PBAT/TPS formulations (15/15/70% and 20/10/70% by mass) by 25.2% and 24.7% compared to the acid-free formulations. There was no significant difference in SR (19.0%–20.1%). These materials were sensitive to moisture since the equilibrium moisture content increased pronouncedly from water activity of 0.5. Films showed good thermal stability, with a maximum decomposition temperature close to pure polyesters. CA did not increase the thermal stability of blends, probably because of the low content used (0.1%). Given the outcomes of this study, these films could be deemed appropriate for applications in food packaging.     

生育酚及其衍生物保护自由基诱导的生物大分子损伤和抑制HepG2细胞增殖的作用

本研究对比了生育酚（tocopheryl,VE）、生育酚琥珀酸酯（α-tocopheryl succinate,α-TOS）、生育酚 聚乙二醇1000琥珀酸酯（tocopheryl polyethylene glycol 1000 succinate,TPGS）对自由基诱导的蛋白质、脂质、 DNA氧化损伤的保护作用,以及对人肝癌细胞（HepG2细胞）增殖抑制作用的差异。结果表明：TPGS对生物 大分子氧化损伤的保护作用最明显,α-TOS次之,VE效果最弱。α-TOS、TPGS均能显著降低HepG2细胞存活率 （P＜0.05）,其中TPGS效果更佳,而VE对HepG2细胞增殖无显著影响（P＞0.05）。这可能是由于两亲性的TPGS 疏水端吸附在生物大分子表面,亲水端在缓冲液中充分伸展,形成较大的空间位阻,保护生物大分子免受自由基攻 击;同时,更好的水溶性使TPGS更易透过生物膜,提高了其在HepG2细胞内的有效浓度。本研究可为生育酚衍生 物应用于健康营养食品提供理论依据。     

Lack of Major Genome-Wide DNA Methylation Changes in Succinate-Treated Human Epithelial Cells

The tricarboxylic acid (TCA) metabolite, succinate, is a competitive inhibitor of dioxygenase enzymes that require alpha ketoglutarate as a cofactor. One family of dioxygenases are the ten-eleven translocation (TET) proteins, which oxidize 5-methylcytosine to promote DNA demethylation. Inhibition of DNA demethylation is expected to lead to DNA hypermethylation, at least at genomic regions at which TET proteins are engaged. We treated human bronchial epithelial cells with succinate for five days and confirmed its effect on TET protein function by observing diminished formation of 5-hydroxymethylcytosine, the first oxidation product of the TET enzymatic reaction. We then analyzed global DNA methylation patterns by performing whole-genome bisulfite sequencing. Unexpectedly, we did not observe differentially methylated regions (DMRs) that reached genome-wide statistical significance. We observed a few regions of clustered DNA hypomethylation, which was also not expected based on the proposed mechanisms. We discuss potential explanations for our observations and the implications of these findings for tumorigenesis.     

生物降解聚丁二酸丁二醇/二甘醇酯的合成与性能研究

以丁二酸(SA)、1,4-丁二醇(BD)和二甘醇(DEG)为原料,通过直接聚合法合成了可生物降解的聚丁二酸丁二醇/二甘醇酯(PBDGS)。采用1H-NMR,GPC,DSC等对产物进行了表征,研究了物料配比对共聚酯热性能、力学性能、降解性能和亲水性的影响。结果表明,DEG的引入能够有效抑制聚酯链段的结晶能力,同时改善材料的亲水性,使其降解性能较纯PBS有显著提高。     

端环氧基型超支化聚合物对PPC/PBS共混物的改性研究

以端环氧基型超支化聚合物(EHBP)为改性剂,采用熔融共混法制备了聚碳酸亚丙酯(PPC)/聚丁二酸丁二醇酯(PBS)/EHBP共混物;通过动态热机械分析仪、热失重分析仪、力学性能测试、旋转流变仪、扫描电子显微镜等对其进行表征.结果表明,加入EHBP使PPC和PBS间的玻璃化转变温度差(ΔTg)减小,表明其界面相容性得到...     

New cyanobacterial strains for biohydrogen production

Under certain conditions, cyanobacteria can switch from photosynthesis to hydrogen production, which is a good energy carrier. However, the biological diversity of hydrogen-releasing cyanobacteria has a great unexplored potential. This study is aimed to investigate the ability of new strains of cyanobacteria Cyanobacterium sp. IPPAS B-1200, Dolichospermum sp. IPPAS B-1213, and Sodalinema gerasimenkoae IPPAS B-353 to release H₂ and to evaluate the effects of photosystem II inhibitor 3-(3,4-dichlorphenyl)-1,1-dimethylurea (DCMU) on H₂ production under light and dark conditions. The results showed that cultures treated with DCMU produced several times more H₂ than untreated cells. The highest rate of H₂ photoproduction of 4.24 μmol H₂ (mg Chl a h)^?1 was found in a Dolichospermum sp. IPPAS B-1213 culture treated with 20 μM DCMU.     

QuEChERS–液相色谱–串联质谱法测定生咖啡中19种琥珀酸脱氢酶抑制剂类杀菌剂残留

本研究旨在建立QuEChERS前处理技术结合液相色谱串联质谱仪（LC-MS/MS）同时测定生咖啡中19种琥珀酸脱氢酶抑制剂（Succinate dehydrogenase inhibitor）杀菌剂残留量的分析方法。生咖啡粉末样品经乙腈均值提取，采用无水硫酸镁、PSA、C18净化剂净化，经液相色谱–串联质谱仪在正离子模式下扫描分析19种琥珀酸脱氢酶抑制剂类杀菌剂残留，通过空白基质匹配标准溶液外标法定量。19种琥珀酸脱氢酶抑制剂类杀菌剂在1～100ng/mL范围内呈良好线性关系（r>0.995），在0.01、0.05和0.1mg/kg的加标水平下，平均回收率为79.6%～109.4%，相对标准偏差（relative standard deviations,RSD,n=6）为1.4%～9.7%，方法检出限为0.51～4.60μg/kg。该方法具有良好的线性关系，准确度和精密度均满足定量分析的要求，适用于生咖啡中19种琥珀酸脱氢酶抑制剂类杀菌剂农药残留的定量分析。     

Improved Cytotoxicity and Induced Apoptosis in HeLa Cells by Co-loading Vitamin E Succinate and Curcumin in Nano-MIL-88B-NH2

One of the strategies for improved therapeutic effects in cancer therapy is combination chemotherapy. In this study, a flexible nano-MOF (Fe-MIL-88B-NH₂) was synthesized in a sonochemical process, then co-loaded with α-tocopheryl succinate (TOS) and curcumin (CCM). The anticancer activity of co-loaded Fe-MIL-88B-NH₂ (Fe-MIL-88B-NH₂/TOS@CCM) against the HeLa cells was compared with that of the single-loaded counterpart (Fe-MIL-88B-NH₂@CCM). MTT analysis indicates improved cytotoxicity of Fe-MIL-88B-NH₂/TOS@CCM. The data from the cell apoptosis assay indicated more apoptosis in the case of the co-loaded nano-MOF. This study indicates the positive effect of the presence of TOS on enhancing the anticancer effect of Fe-MIL-88B-NH₂@CCM to prepare a more efficient drug delivery nanosystem.