正交试验优选槟榔鞣质的提取工艺

目的:优选槟榔中鞣质的最佳提取工艺.方法:采用正交设计方案和干酪素法,以槟榔提取液中总鞣质含量为指标,考查影响鞣质提取的因素,优化槟榔鞣质的提取方法和条件.结果:槟榔鞣质最佳提取方法为超声提取法,其最佳工艺为:用80%丙酮,料液比1:10,超声提取1次,每次2 h,所得槟榔鞣质含量为7.68%.结论:该提取工艺合理、可行,适用于实验室槟榔鞣质的提取.     

重组人半乳糖苷结合凝集素-9质粒的构建及表达

目的构建人半乳糖苷结合凝集素-9(Galectin-9)的真核表达质粒pGalectin-9,并检测其表达。方法通过DNA重组技术和PCR方法从人外周血单个核细胞克隆Galectin-9基因,插入真核表达质粒pcDNA3.1(+)中,通过PCR、酶切及测序鉴定重组载体的正确性;采用脂质体转染技术将重组质粒pGalectin-9瞬时转染中国仓鼠卵巢(Chinesehamster ovary,CHO)细胞,通过Western blot、RT-PCR和间接免疫荧光方法检测Galectin-9的表达。结果 DNA测序和酶切鉴定证明Galectin-9基因正确克隆至pcDNA3.1(+)的多克隆位点;以重组质粒pGalectin-9瞬时转染CHO细胞,通过Western blot、RT-PCR和间接免疫荧光方法,在分子和细胞水平证实Galectin-9的表达。结论成功构建pGa-lectin-9的重组质粒,并证实其在CHO细胞中可以成功表达。     

Intracellular chromosome breaks on silicon surface

The genotoxicity of silicon (Si) is investigated by soaking crystalline Si in a complete culture medium for 60 days and conducting micronuclei tests (MNTs) utilizing hamster ovary (CHO) cells and its Ku80 deficient CHO mutant (xrs5) cells (DNA double-strand breaks repair deficiency). The intracellular concentrations of reactive oxygen/nitrogen species (ROS/RNS) on Si are determined to elucidate the relationship between ROS/RNS and Si-induced genotoxicity by using CHO cells. The cells are treated with ROS scavenger (dimethyl sulfoxide) and MNT are performed. The results indicate that the intracellular concentration of ROS and nitrogen oxide (NO) on Si is higher than those on the control group by about 38% and 12%. ROS/RNS include superoxide (O₂^?) anion, NO, and peroxynitrite (ONOO^?) which can injure chromosomes and induce high cellular DNA double-strand breaks (DSBs).     

凝血因子Ⅶ及其受体相互作用的研究进展

1前言 活化形式的凝血因子Ⅶ及其受体组织因子（TF）形成的TF／FⅦa复合物被认为是引发凝血瀑布的关键蛋白。当血管受损伤时,TF暴露,并与FⅦ或FⅦa1：1结合,TF／FⅦa复合物能增加FⅦa对其底物Ⅸ和FX的蛋白水解活性,所以能激活内、外源性凝血途径。TF／FⅦa复合物在正常生理性止血中发挥着重要作用,并且与血栓性疾病的发生和发展有关,除此之外,TF可在肿瘤细胞和肿瘤血管内皮细胞表达,并参与肿瘤血管生成,促进肿瘤生长、浸润与转移。血浆中FⅦ与TF的水平与多种肿瘤的预后、分化等密切相关。了解TF、FⅦ结构和相互作用机制对于探讨如何有效干预TF／FⅦa复合物形成,从而防治多种疾病的发生和发展至关重要。本文就近年来关于FⅦ及其受体TF的结构功能、结合机制等方面研究进展作一简要综述。     

聚肌胞滴鼻剂治疗儿童支气管哮喘的临床疗效观察

目的观察聚肌胞滴鼻剂治疗儿童支气管哮喘的疗效。方法将哮喘患儿226例随机分成两组：A组（对照组）112例,B组（药物组）114例,在儿童支气管哮喘防治常规处理的基础上,B组连用0.1%聚肌胞滴鼻剂9个月,在相等时间段内记录两组哮喘发作次数,日间、夜间症状评分,每次临床症状完全缓解时间,计算并比较两组各分数,判断其近、远期疗效。结果B组比A组在近、远期疗效中平均哮喘分数及次数分数、症状分数差异均非常显著（P〈0.001）,平均病程分数在近期疗效中差异非常显著（P〈0.01）,在远期疗效中差异显著（P〈0.05）。结论0.1%聚肌胞滴鼻剂治疗儿童支气管哮喘近远期疗效确切,可使患儿哮喘发作次数减少,每次发作症状减轻、病程缩短。     

单独发生于脑干的脑后部可逆性脑病综合征1例

脑后部可逆性脑病综合征(Posterior reversible encephalopathy syndrome,PRES)是近年来认识的一种可逆性神经综合征.其症状包括头痛、癫痫、意识错乱、视物模糊等,多伴有明显的高血压.最早于1996年由Hinchey提出,MRI最突出的表现是累及大脑半球后部(顶枕叶为主)白质区弥漫性对称性大片长T1长T2信号,并且呈可逆性.随着人们认识的提高,发现病变不仅累及顶枕叶白质,还可累及皮层、脑干及小脑等其它区域,并且也可引起不可逆性神经功能缺失.我院即发现1例单独发生于脑干的不典型PRES,现报告如下.     

Hierarchical targeted hepatocyte mitochondrial multifunctional chitosan nanoparticles for anticancer drug delivery

The overwhelming majority of drugs exert their pharmacological effects after reaching their target sites of action, however, these target sites are mainly located in the cytosol or intracellular organelles. Consequently, delivering drugs to the specific organelle is the key to achieve maximum therapeutic effects and minimum side-effects. In the work reported here, we designed, synthesized, and evaluated a novel mitochondrial-targeted multifunctional nanoparticles (MNPs) based on chitosan derivatives according to the physiological environment of the tumor and the requirement of mitochondrial targeting drug delivery. The intelligent chitosan nanoparticles possess various functions such as stealth, hepatocyte targeting, multistage pH-response, lysosomal escape and mitochondrial targeting, which lead to targeted drug release after the progressively shedding of functional groups, thus realize the efficient intracellular delivery and mitochondrial localization, inhibit the growth of tumor, elevate the antitumor efficacy, and reduce the toxicity of anticancer drugs. It provides a safe and efficient nanocarrier platform for mitochondria targeting anticancer drug delivery.     

Synthesis of nitrogen-doped graphene wrapped SnO2 hollow spheres as high-performance microwave absorbers

Nitrogen-doped graphene (NG)/SnO₂ hollow sphere hybrids were synthesized in this work. The chemical composition, crystal structure and morphology have been characterized by FT-IR spectra, XRD, Raman spectra, XPS, SEM and TEM in detail. Reflection loss (RL) values of NG/SnO₂ hollow sphere hybrids less than −10 dB and −20 dB are found in the wide frequency range of 4.5–18 GHz and 5–16.2 GHz within 1.3–3.5 mm, and a minimum RL of −50.3 dB is achieved at 8.6 GHz with the matching thickness of only 2.3 mm. The results indicate that the NG/SnO₂ hollow sphere hybrids with high-performance microwave absorption properties have a promising future in decreasing electromagnetic wave irradiation and interference.

Nitrogen-doped graphene/SnO₂ hollow sphere hybrids were synthesized and show high-performance microwave absorption properties.     

N-doped TiO2 nanotube arrays with uniformly embedded CoxP nanoparticles for high-efficiency hydrogen evolution reaction

Efficient and stable non-precious metal based electrocatalysts are crucial to the hydrogen evolution reaction (HER) in renewable energy conversion. Herein, Co_xP nanoparticles (NPs) are uniformly embedded in N-doped TiO₂ nanotube arrays (Co_xP/N-TiO₂ NTAs) by low-temperature phosphorization of the precursor of metallic cobalt NPs embedded in N-doped TiO₂ NTAs (Co/N-TiO₂ NTAs) which were fabricated by phase separation of CoTiO₃ NTAs in ammonia. Owing to the abundant exposed surface active sites of Co_xP NPs, tight contact between the Co_xP NPs and TiO₂ NTAs, fast electron transfer in N-doped TiO₂, and channels for effective diffusion of ions and H₂ bubbles in the tubular structure, the Co_xP/N-TiO₂ NTAs have excellent electrocatalytic activity in HER exemplified by a low overpotential of 180 mV at 10 mA cm⁻² and small Tafel slope of 51 mV dec⁻¹ in 0.5 M H₂SO₄. The catalyst also shows long-term cycling stability and is a promising non-precious metal catalyst for HER.

Co_xP NPs embedded in N-doped TiO₂ NTAs was fabricated by phase separation of CoTiO₃ and delivers high efficient and stable HER performance in acid solution.