HPLC测定灵芝子实体水提物及相关产品中三萜的含量

灵芝药品大多以灵芝子实体水提物为原料,为快速准确测定灵芝子实体水提物及相关产品中三萜的含量,建立了具有较好分离效果的HPLC分析测定方法。通过优化色谱柱和洗脱条件,优选出Agilent Zorbax SB-Aq C18色谱柱(250 mm×4.6 mm,5μm),以乙腈-乙酸水溶液(0.01%)为流动相梯度洗脱,流速为1.0 mL/min,检测波长252 nm,柱温30℃,该条件下灵芝酸A、灵芝酸F等10种灵芝酸得到较好的分离。方法学考察显示该分析方法精密度、重复性、稳定性和加样回收率的RSD值均小于5%,可以用于灵芝酸C2、灵芝酸G、灵芝烯酸B、灵芝酸B等10种灵芝酸的定量检测。通过对灵芝子实体原料、水提物和市售灵芝产品中10种三萜类成分分析发现,灵芝子实体水提物中均含有这10种三萜,含量为2.52%–6.83%,较子实体原料大幅提高,市售的灵芝产品中的三萜含量为0.27%–0.84%。该方法的建立为灵芝水提物及其产品质量标准的建立奠定基础。     

Ten simple rules to host an inclusive conference

Conferences are spaces to meet and network within and across academic and technical fields, learn about new advances, and share our work. They can help define career paths and create long-lasting collaborations and opportunities. However, these opportunities are not equal for all. This article introduces 10 simple rules to host an inclusive conference based on the authors’ recent experience organizing the 2021 edition of the useR! statistical computing conference, which attracted a broad range of participants from academia, industry, government, and the nonprofit sector. Coming from different backgrounds, career stages, and even continents, we embraced the challenge of organizing a high-quality virtual conference in the context of the Coronavirus Disease 2019 (COVID-19) pandemic and making it a kind, inclusive, and accessible experience for as many people as possible. The rules result from our lessons learned before, during, and after the organization of the conference. They have been written mainly for potential organizers and selection committees of conferences and contain multiple practical tips to help a variety of events become more accessible and inclusive. We see this as a starting point for conversations and efforts towards building more inclusive conferences across the world. * Translated versions of the English abstract and the list of rules are available in 10 languages in S1 Text: Arabic, French, German, Italian, Japanese, Korean, Portuguese, Spanish, Tamil, and Thai.     

黄土高原不同树种枯落叶混合分解效应

混交林中不同树种枯落物混合分解是否产生促进或抑制作用是评价种间关系和混交适宜性的重要依据之一。以黄土高原主要树种为对象,通过室内枯落叶混合分解模拟试验,结果表明:(1)沙棘、白榆、柠条和小叶杨枯落叶分解最快(周转期1 a左右),其次为旱柳、侧柏和白桦枯落叶(周转期略大于1 a),紫穗槐、辽东栎和刺槐枯落叶分解稍慢(周转期1.5 a左右),而樟子松、落叶松和油松枯落叶分解最慢(周转期略大于2 a)。(2)对于针叶树,与油松枯落叶混合,存在明显促进分解作用的是侧柏、落叶松,其次是白桦、沙棘和刺槐;与樟子松枯落叶混合,存在明显促进分解作用的是落叶松、侧柏、沙棘、白榆,其次是柠条、紫穗槐和小叶杨,而存在明显抑制分解作用的是刺槐,其次是白桦和辽东栎;与落叶松枯落叶混合,存在较明显促进分解作用的是白榆、白桦和辽东栎,存在较明显抑制作用的是刺槐;紫穗槐与侧柏枯落叶混合存在较明显的抑制分解作用。(3)对于阔叶树,与小叶杨枯落叶混合,存在较明显促进分解作用的是紫穗槐,其次是辽东栎和刺槐;与刺槐枯落叶混合,存在较明显促进分解作用的是白榆和沙棘,存在明显抑制分解作用的是柠条,其次是辽东栎和白桦;与白桦枯落叶混合,存在较明显促进分解作用的是辽东栎和紫穗槐,存在较明显抑制分解作用的是柠条;白榆与辽东栎、旱柳枯落叶混合均存在较明显的促进分解作用,而白榆与柠条枯落叶混合存在较明显的抑制分解作用;紫穗槐与旱柳、沙棘枯落叶混合均存在较明显的促进分解作用,而紫穗槐与柠条枯落叶混合有较明显的抑制作用。     

城镇化背景下深圳典型流域鱼类群落特征及驱动因子

理解城镇的快速发展对河流鱼类群落结构的影响,是城镇河流科学管理和生物多样性保护的关键基础。本研究于2019年丰水期（8月）和枯水期（11月）,选取我国城镇化典型城市-深圳域内两个处于不同城镇化程度的代表性流域,应用多重统计方法比较分析了流域间鱼类群落结构的差异,并探讨了驱动鱼类群落变异的关键环境要素。结果发现,城镇化程度高的观澜河流域其鱼类种类组成、优势类群、生物多样性指数与城镇化程度低的坪山河流域有明显差别。 具体表现为：城镇化程度高的流域土著敏感种类如异鱲、吸鳅等几近消失,优势类群为外来入侵耐受种类,其物种多样性显著低于城镇化程度低的流域（P<0.05）。同时,外来鱼类在城镇河段其数量占比平均达92.5%,广泛分布于深圳城镇河流中。在环境因素方面,城镇化程度高的观澜河流域水体理化指标总氮、总磷、氨氮、化学需氧量、生化需氧量、高锰酸盐指数均显著性高于城镇化程度低的坪山河流域（P<0.05）。基于Bray-Curtis距离的冗余分析显示：城镇用地占比和总氮是影响观澜河和坪山河流域鱼类群落差异的主要因素。城镇化进程中河流生境的改变已影响到土著鱼类的生物多样性。因此,推动以恢复土著鱼类生物多样性的河流生态治理与保护是今后水生态目标管理的重要方向。     

Comparing Protein Expression in Erwinia amylovora Strain TS3128 Cultured under Three Sets of Environmental Conditions

Erwinia amylovora, the causal agent of fire-blight disease in apple and pear trees, was first isolated in South Korea in 2015. Although numerous studies, including omics analyses, have been conducted on other strains of E. amylovora, studies on South Korean isolates remain limited. In this study, we conducted a comparative proteomic analysis of the strain TS3128, cultured in three media representing different growth conditions. Proteins related to virulence, type III secretion system, and amylovoran production, were more abundant under minimal conditions than in rich conditions. Additionally, various proteins associated with energy production, carbohydrate metabolism, cell wall/membrane/envelope biogenesis, and ion uptake were identified under minimal conditions. The strain TS3128 expresses these proteins to survive in harsh environments. These findings contribute to understanding the cellular mechanisms driving its adaptations to different environmental conditions and provide proteome profiles as reference for future studies on the virulence and adaptation mechanisms of South Korean strains.     

Protective Role of miR-34c in Hypoxia by Activating Autophagy through BCL2 Repression

Hypoxia leads to significant cellular stress that has diverse pathological consequences such as cardiovascular diseases and cancers. MicroRNAs (miRNAs) are one of regulators of the adaptive pathway in hypoxia. We identified a hypoxia-induced miRNA, miR-34c, that was significantly upregulated in hypoxic human umbilical cord vein endothelial cells (HUVECs) and in murine blood vessels on day 3 of hindlimb ischemia (HLI). miR-34c directly inhibited BCL2 expression, acting as a toggle switch between apoptosis and autophagy in vitro and in vivo. BCL2 repression by miR-34c activated autophagy, which was evaluated by the expression of LC3-II. Overexpression of miR-34c inhibited apoptosis in HUVEC as well as in a murine model of HLI, and increased cell viability in HUVEC. Importantly, the number of viable cells in the blood vessels following HLI was increased by miR-34c overexpression. Collectively, our findings show that miR-34c plays a protective role in hypoxia, suggesting a novel therapeutic target for hypoxic and ischemic diseases in the blood vessels.     

Age‐related memory vulnerability to interfering stimuli is caused by gradual loss of MAPK‐dependent protection in Drosophila

Age‐related memory impairment (AMI) is a common phenomenon across species. Vulnerability to interfering stimuli has been proposed to be an important cause of AMI. However, the molecular mechanisms underlying this vulnerability‐related AMI remain unknown. Here we show that learning‐activated MAPK signals are gradually lost with age, leading to vulnerability‐related AMI in Drosophila. Young flies (2‐ or 3‐day‐old) exhibited a significant increase in phosphorylated MAPK levels within 15 min after learning, whereas aged flies (25‐day‐old) did not. Compared to 3‐day‐old flies, significant 1 h memory impairments were observed in 15‐, 20‐, and 30‐day‐old flies, but not in 10‐day‐old flies. However, with post‐learning interfering stimuli such as cooling or electric stimuli, 10‐day‐old flies had worse memory performance at 1 h than 3‐day‐old flies, showing a premature AMI phenomenon. Increasing learning‐activated MAPK signals through acute transgene expression in mushroom body (MB) neurons restored physiological trace of 1 h memory in a pair of MB output neurons in aged flies. Decreasing such signals in young flies mimicked the impairment of 1 h memory trace in aged flies. Restoring learning‐activated MAPK signals in MB neurons in aged flies significantly suppressed AMI even with interfering stimuli. Thus, our data suggest that age‐related loss of learning‐activated neuronal MAPK signals causes memory vulnerability to interfering stimuli, thereby leading to AMI.