Study on Biological Safety of Polyvinyl Alcohol/Collagen Hydrogel as a Tissue Substitute (II)

Physically crosslinked polyvinyl alcohol/collagen composite hydrogels were prepared by a cyclic freezing-drying technique. The biological properties of the hydrogels, including hemolysis, anaphylaxis, pyrogen and acute systemic toxicity tests and implantation in-vivo, were investigated. The hemolysis test suggested that the polyvinyl alcohol/collagen, with a hemolysis index of 1.19%, did not have an obvious hemolysis reaction. There was no toxicosis or death cases observed in the acute systemic toxicity test, and the hydrogel showed no anaphylaxis or pyrogen response. The composite hydrogel showed a good histological compatibility in the in-vivo study. The results indicated that the polyvinyl alcohol/collagen composite hydrogels have promising applications for pharmaceutical and biomedical fields.     

钙钛矿ABX3型材料的结构与性质调控

近年来,钙钛矿太阳能电池由于其效率高、制造成本低、工艺简单等特点受到广泛关注,成为目前太阳能电池领域的研究热点。在钙钛矿太阳能电池中,无机-有机杂化ABX₃材料非常重要。它既作为光吸收材料,同时又作为载流子传输材料,因此它的光电性质直接影响到太阳能电池的效率。本文综述了调控钙钛矿型无机有机金属卤化物ABX₃结构和性质的几种途径。     

紫外光谱法测定乙酸乙烯酯中的对苯二酚

采用紫外光谱法测定乙酸乙烯酯中对苯二酚含量时,乙酸乙烯酯中的有机杂质会对测试结果产生影响.其中乙醛、丙酮对测试结果的影响程度基本呈线性递增关系,而醋酸甲酯、醋酸乙酯对测试结果不会产生影响.     

茶皂素―金属复合抗菌剂的制备及抗菌性能研究

通过抑菌环法探讨了茶皂素、金属离子、茶皂素―金属复合抗菌剂对大肠杆菌和金黄色葡萄球菌的抗菌活性,考察了茶皂素纯度、浓度、金属离子种类等因素对抗菌剂抗菌活性的影响。结果表明,茶皂素的抗菌活性与单一的金属离子的抗菌活性相当,茶皂素对大肠杆菌的最低抑制浓度为5 mg/mL,对金黄色葡萄球菌的最低抑制浓度是10 mg/mL;茶皂素与金属离子复配抗菌活性具有协同效应,尤其茶皂素―锌复合抗菌剂对大肠杆菌的抑制效果大大加强。     

A rapid and convenient method for preparative separation of three indissolvable polyphenols from Euphorbia pekinensis by the flexible application of solvent extraction combined with counter‐current chromatography

A rapid and convenient method was established to preparatively isolate the three ellagic acid types of compounds, which were the main polyphenols in Euphorbia pekinensis, by flexibly applying solvent extraction combined with counter‐current chromatography (CCC). The total extract (extracted using 95% ethanol) of E. pekinensis was pretreated by two simple steps before CCC isolation, following the procedure: the total extract was extracted by classical solvent extraction using petroleum ether and ethyl acetate, respectively, and then the ethyl acetate extract was suspended using 95% ethanol, after being allowed to stand overnight, the sediment was obtained. Partial sediment (100 mg) was then directly separated by CCC with a two‐phase solvent system composed of chloroform‐95% ethanol‐water‐85% formic acid (50:50:50:5, v/v/v/v). About 22 mg of 3,3′‐dimethoxy ellagic acid (1), 12 mg of 3,3′‐di‐O‐methyl‐4‐O‐(β‐d ‐xylopyranosyl)ellagic acid (2), and 35 mg of ellagic acid (3) with purities of 96.0, 95.2, and 95.4% were obtained respectively in one step within 4 h. After being purified by washing with methanol, the purities of the three compounds obtained were all above 98%. The purities were determined by HPLC and their chemical structures were further identified by ¹H and ¹³C NMR spectroscopy. The recoveries were calculated as 84.6, 85.7, and 89.5%, respectively. The result demonstrated that the present isolation method was rapid, economical and efficient for the preparative separation of polyphenols from E. pekinensis.     

免疫亲和柱净化-液相色谱-串联质谱法同时测定猪肉中6种玉米赤霉醇类化合物残留量

建立了猪肉中6种玉米赤霉醇类化合物残留量的免疫亲和柱净化-液相色谱-串联质谱(IAC-LC-MS/MS)分析方法。酶解后的样品用乙醚提取,提取液浓缩后用三氯甲烷溶解,NaOH溶液反萃取,经免疫亲和柱富集和净化后,采用LC-MS/MS进行测定,外标法定量。在Shimadzu Shim-pack VP-ODS C18反相柱上分离,梯度洗脱,流动相为乙腈和2 mmol/L乙酸铵溶液;质谱采集为电喷雾负离子多反应监测模式。6种目标物的线性范围为0.5～200μg/L,相关系数(R)大于0.999,定量限(LOQ)在0.05～0.63μg/kg之间;添加浓度在1.0～5.0μg/kg范围内,方法回收率为71.3%～93.7%,相对标准偏差在3.7%～9.7%之间。该方法灵敏度高、重现性好,适用于猪肉样品中痕量玉米赤霉醇类药物残留的测定。     

基于2-[1-(2-羟基乙亚胺基)乙基]苯酚的六核铁(Ⅲ)配合物的合成、晶体结构、热稳定性及抗菌活性研究

利用三齿席夫碱配体2-[1-(2-羟基乙亚胺基)乙基]苯酚(H2L)和二氰氨钠与氯化铁在甲醇中反应,制备了一个新的具有中心对称性的六核铁(Ⅲ)配合物[NaFe6L6(MeO)6]Cl。通过利用元素分析、红外光谱和X-射线单晶衍射表征了该配合物的结构。配合物的晶体以三斜晶系P1空间群结晶,其晶体学参数a=1.162 5(2)nm,b=1.396 4(2)nm,c=1.504 2(2)nm,α=66.154(7)°,β=68.809(7)°,γ=73.296(7)°,V=2.053 6(5)nm3,Z=1,R1=0.059 3,wR2=0.156 4。本文还研究了该配合物的热稳定性和抗菌活性。     

含语音增强模块的i-向量说话人识别性能分析

为解决文本无关说话人识别中训练与识别环境不同导致模式失配的问题,提出了一种采用语音增强模块进行前端预处理的i-向量说话人识别系统,从而提高系统对于环境噪声的鲁棒性.为评估不同语音增强算法的性能,利用NIST08核心测试集进行仿真实验.采用IMCRA算法对语音进行噪声估计后,分别用维纳滤波法、MMSE-LSA、传统谱减法和多频带谱减法等4种方法进行语音增强前端处理,在基于i-向量的说话人识别系统下进行实验.实验结果表明采用了语音增强的系统具有一定抗噪声性能,并且在高信噪比条件下,基于多频带的谱减法在此系统下性能最佳,而低信噪比情况下MMSE-LSA算法更有优势.     

LeDock与PyMOL软件在天然产物化学课程教学中的应用*——以中药防治新冠病毒肺炎(COVID-19)为例

以中药防治新冠病毒肺炎(COVID-19)为例,在天然产物化学课程教学中借助LeDock软件进行天然产物小分子与受体蛋白分子之间的半柔性对接,用PyMOL软件分析天然产物小分子与受体蛋白分子之间的相互作用,全方位充分展示天然产物分子结构和功能之间的关系。教学围绕我国当前形势展开,让学生在了解事实的同时激发其学习热情,培养学生的逻辑思维能力和动手能力,以此来提高教学质量。     

高微量元素豆芽研究

以豆芽作为载体,通过其发芽过程使无机铁、锌转换为有机铁、锌.在发芽以前通过控制添加剂量可以形成高铁和高锌豆芽.此种豆芽可以作为铁源和锌源,更易被人们所接受,并且为治疗和预防锌、铁微量元素缺乏症开辟了一条更可行的途径.