高压静电场分离水稻、油菜及芝麻种子对萌发期生物效应的影响

落入高压静电场内的水稻、芝麻及油菜种子,在场的作用下,即产生沿电场方向的位移,在同一跌落高度下,重量基本相同的种子,其分离距离产生很大的差异,且分离距离与种子的发芽率及发芽势的改善程度存在着较为明显的相关关系,研究中证实,种子活力强度得到提高,其α淀粉酶活性、蛋白酶活性、脂肪酶活性及电导率得到明显的改善。     

山东淄博第四纪裂隙动物群

简要记述产自山东淄博孙家山裂隙群的主要哺乳动物化石,将之分为A、B、C三个动物群。A动物群时代与周口店第18地点相当,为早更新世早期;B动物群时代与周口店第9地点相当,为早更新世晚期;C动物群则可能与周口店第1地点中上部层位的时代相当,为中更新世中晚期。分析不同种类的生态类型并依据最小个体数的统计结果,认为早更新世早期本区为相对温湿的草原环境,附近可能有荒漠化现象;早更新世晚期气候较为温湿,无荒漠化现象;中晚更新世主要为林缘—灌丛环境,气候更为湿润。A动物群是华北地区早更新世早期特有的动物群,略具南北过渡区的特征;B动物群初具现代动物区系的面貌;C动物群基本与现代动物区系一致。     

裂褶菌多糖的构象研究

从裂褶菌中提取一水溶性多糖Sci.气相色谱,高碘酸盐氧比,甲基化分析等确定它为葡聚糖.1-3糖苷键构成其主链,平均三分之一的主链残基在6位带有分枝,红外光谱和三氧化铬氧化表明Scl全部残基为β构型,在不同的温度和不同的酸碱浓度状态下,检查糖链与刚果红形成络合物的能力以及Scl水溶液的粘度和旋光值.推测低温近中性Scl主要呈单股螺旋构象.升温或提高酸碱浓度导致有规则的螺旋构象转变成无规则的线团.高碘酸盐氧化去掉分枝则多股螺旋比例在构象中增加.     

耐热蛋白质延长因子(EF-Tu)的分子和功能的性质(英文)

本文用亲和层析法从Calderobacteriumhydrogenophilum(极端耐热细菌)中分离得到纯的耐热蛋白质延长因子。测得其相对的分子量为51000。该蛋白质对热极其稳定,从膜过滤分析法测定EF-Tu 的活性可知,在80℃加热5 min后,原活性仅仅失去50%。Ouchterlony双向免疫扩散的结果表明,该蛋白延长因子与E.coli 延长因子有着抗原的相似性。而且该因子只含一个半胱氨酸残基,其位置在半胱氨酸81,即肽段T_(13)。Southern 杂交试验的结果显示出C.hydrogenophilum 的染色体DNA 中可能有两个基因编码同一蛋白。     

Circ_0008542 in osteoblast exosomes promotes osteoclast-induced bone resorption through m6A methylation

With an increasing aging society, China is the world’s fastest growing markets for oral implants. Compared with traditional oral implants, immediate implants cause marginal bone resorption and increase the failure rate of osseointegration, but the mechanism is still unknown. Therefore, it is important to further study mechanisms of tension stimulus on osteoblasts and osteoclasts at the early stage of osseointegration to promote rapid osseointegration around oral implants. The results showed that exosomes containing circ_0008542 from MC3T3-E1 cells with prolonged tensile stimulation promoted osteoclast differentiation and bone resorption. Circ_0008542 upregulated Tnfrsf11a (RANK) gene expression by acting as a miR-185-5p sponge. Meanwhile, the circ_0008542 1916-1992 bp segment exhibited increased m6A methylation levels. Inhibiting the RNA methyltransferase METTL3 or overexpressing the RNA demethylase ALKBH5 reversed osteoclast differentiation and bone resorption induced by circ_0008542. Injection of circ_0008542 + ALKBH5 into the tail vein of mice reversed the same effects in vivo. Site-directed mutagenesis study demonstrated that 1956 bp on circ_0008542 is the m6A functional site with the abovementioned biological functions. In conclusion, the RNA methylase METTL3 acts on the m6A functional site of 1956 bp in circ_0008542, promoting competitive binding of miRNA-185-5p by circ_0008542, and leading to an increase in the target gene RANK and the initiation of osteoclast bone absorption. In contrast, the RNA demethylase ALKBH5 inhibits the binding of circ_0008542 with miRNA-185-5p to correct the bone resorption process. The potential value of this study provides methods to enhance the resistance of immediate implants through use of exosomes releasing ALKBH5.Subject terms: Epigenetics, Predictive markers     

Gastrodin relieves inflammation injury induced by lipopolysaccharides in MRC‐5 cells by up‐regulation of miR‐103

The beneficial function of gastrodin towards many inflammatory diseases has been identified. This study designed to see the influence of gastrodin in a cell model of chronic obstructive pulmonary disease (COPD). MRC‐5 cells were treated by LPS, before which gastrodin was administrated. The effects of gastrodin were evaluated by conducting CCK‐8, FITC‐PI double staining, Western blot, qRT‐PCR and ELISA. Besides this, the downstream effector and signalling were studied to decode how gastrodin exerted its function. And dual‐luciferase assay was used to detect the targeting link between miR‐103 and lipoprotein receptor‐related protein 1 (LRP1). LPS induced apoptosis and the release of MCP‐1, IL‐6 and TNF‐α in MRC‐5 cells. Pre‐treating MRC‐5 cells with gastrodin attenuated LPS‐induced cell damage. Meanwhile, p38/JNK and NF‐κB pathways induced by LPS were repressed by gastrodin. miR‐103 expression was elevated by gastrodin. Further, the protective functions of gastrodin were attenuated by miR‐103 silencing. And LRP1 was a target of miR‐103 and negatively regulated by miR‐103. The in vitro data illustrated the protective function of gastrodin in LPS‐injured MRC‐5 cells. Gastrodin exerted its function possibly by up‐regulating miR‐103 and modulating p38/JNK and NF‐κB pathways.     

Chemical Composition and Antioxidant Activity of Essential Oil of Chinese Propolis

The chemical composition and in vitro antioxidant activity of the essential oil of propolis (EOP) collected from 25 locations in China was investigated. Steam‐distillation extraction was used to extract the EOP, and chemical composition was identified by GC/MS. The antioxidant activities of EOP were also measured. The result showed that a total of 406 compounds were detected in EOP. The major compounds of Chinese EOP were cedrol, γ‐eudesmol, benzyl alcohol, phenethyl alcohol, 2‐methoxy‐4‐vinylphenol, 3,4‐dimethoxystyrene and guaiol. Principal component analysis revealed the significant correlation between EOP compositions and their origins, and certain correlation was detected between EOP and their color. Linear discriminant analysis showed that 88 % and 84 % of the propolis samples were predicted correctly as the groupings identified by climatic zone and the color, respectively. Furthermore, the differences of antioxidant activities of EOP were significant. EOP of Shandong had the strongest antioxidant activities, whereas EOP of Guangdong, Yunnan and Hunan showed the poorest.     

Sestrin 2 attenuates sepsis‐associated encephalopathy through the promotion of autophagy in hippocampal neurons

Sepsis‐associated encephalopathy (SAE) has typically been associated with a poor prognosis. Although sestrin 2 (SESN2) plays a crucial role in metabolic regulation and the stress response, its expression and functional roles in SAE are still unclear. In the present study, SAE was established in mice through caecal ligation and puncture (CLP). The adeno‐associated virus 2 (AAV2)‐mediated SESN2 expression (ie overexpression and knockdown) system was injected into the hippocampi of mice with SAE, and subsequently followed by electron microscopic analysis, the Morris water maze task and pathological examination. Our results demonstrated an increase of SESN2 in the hippocampal neurons of mice with SAE, 2‐16 hours following CLP. AAV2‐mediated ectopic expression of SESN2 attenuated brain damage and loss of learning and memory functions in mice with SAE, and these effects were associated with lower pro‐inflammatory cytokines in the hippocampus. Mechanistically, SESN2 promoted unc‐51‐like kinase 1 (ULK1)‐dependent autophagy in hippocampal neurons through the activation of the AMPK/mTOR signalling pathway. Finally, AMPK inhibition by SBI‐0206965 blocked SESN2‐mediated attenuation of SAE in mice. In conclusion, our findings demonstrated that SESN2 might be a novel pharmacological intervention strategy for SAE treatment through promotion of ULK1‐dependent autophagy in hippocampal neurons.