Three research priorities for just and sustainable urban systems: Now is the time to refocus

Now is the time to refocus efforts in urban research and design. A changing climate and extreme weather events are presenting unique challenges to urban systems around the world. These challenges illuminate the social barriers that accompany disruptive events such as resource inequities and injustices. In this perspective, we provide three research priorities for just and sustainable urban systems that help to address these matters. The three research priorities are: (1) social equity and justice, (2) circularity, and (3) digital twins. Conceptual context and future research directions are provided for each. For social equity and justice, the future directions are mandatory equity analysis and inclusionary practices, understanding and reconciling historical injustices, and intentional integration with diverse community stakeholders. For circularity applications, they are better metrics for integration, more robust evaluation frameworks, and dynamic modeling at multiple spatial and temporal scales. Future directions for digital twins include developing principles to reduce complexity, integrating model and system components, and reducing barriers to data access. These research priorities are core to meeting several of the United Nations Sustainable Development Goals (i.e., 1—No Poverty, 8—Decent Work and Economic Growth, 10—Reduced Inequalities, and 11—Sustainable Cities and Communities). Useful social and technical matters are discussed throughout, where we highlight the importance of prioritizing localized research efforts, provide guidance for community-engaged research and co-development practices, and explain how these priorities interact to align with the evolving field of industrial ecology.     

Circular RNA SLTM as a miR-421-competing endogenous RNA to mediate HMGB2 expression stimulates apoptosis and inflammation in arthritic chondrocytes

Osteoarthritis (OA) is the most common age-related joint disease characterized by chronic inflammation, progressive articular cartilage destruction, and subchondral sclerosis. Accumulating evidence suggests that circular RNAs (circRNAs) play key roles in OA, but the function of circSLTM in OA remains greatly unknown. Therefore, this study focused on interleukin-1β (IL-1β)-treated primary human chondrocytes as well as a rat model to investigate the expression pattern and functional role of circSLTM in OA in vitro and in vivo. CircSLTM and high mobility group protein B2 (HMGB2) were upregulated in IL-1β-induced chondrocytes, whereas miR-421 was downregulated. Knockdown of circSLTM or overexpression of miR-421 ameliorated IL-1β-induced chondrocyte apoptosis and inflammation. The regulatory relationship between circSLTM and miR-421, as well as that between miR-421 and HMGB2, was predicted by bioinformatics and then verified by the RNA immunoprecipitation experiment and dual-luciferase reporter gene assay. Furthermore, silencing of circSLTM increased cartilage destruction and decreased cartilage tissue apoptosis rate and inflammation in a rat model of OA. Taken together, our findings demonstrate the fundamental role of circSLTM in OA progression and provide a potential molecular target for OA therapy.     

北部湾茅尾海无瓣海桑红树林地上生物量反演——基于XGBoost机器学习算法

无瓣海桑是广西从自治区外引进的外来红树林树种,采用定量化算法精确估算无瓣海桑地上生物量对红树林生态修复以及海洋蓝碳监测提供经验和方法。论文以广西茅尾海自然保护区无瓣海桑红树林为研究对象,以野外实测无瓣海桑红树林地上生物量数据和Sentinel-1/2卫星提取的后向散射数据、波段数据、植被指数数据和纹理指数数据为数据源,通过分析各遥感因子与实测红树林地上生物量之间的重要性关系,采用极端梯度提升(XGBoost)机器学习算法对比了不同的变量组合对模型精度的影响,最后基于优选的变量组合反演了无瓣海桑红树林的地上生物量。结果表明：(1)研究区无瓣海桑红树林实测树高范围为1.55—13.58m,平均值为8.37m,胸径范围为0.7—41cm,平均值为15.62cm;(2)通过XGBoost算法优选的21个特征变量组合模型拟合效果较好,其模型在测试阶段R²=0.7237,RMSE=21.70Mg/hm²。XGBoost算法反演研究区无瓣海桑地上生物量介于19.14—138.46Mg/hm²之间,平均值为51.92Mg/hm^...     

生物可降解塑料单体二元羧酸的生物合成研究进展北大核心CSCD

塑料是最重要的聚合物材料之一,需求量巨大,但存在处理困难、污染大等缺点。环境友好型的生物可降解塑料有望成为目前塑料的替代品,以满足社会各界对于塑料制品日益增长的需求。二元羧酸是生物可降解塑料中重要的单体之一,可降解性强,应用广泛,并且可以通过全生物法合成。因此,本文重点选取了几种比较有代表性的二元羧酸,总结它们的生物合成途径以及其代谢改造手段,以期为中长链等复杂二元羧酸的生物法合成提供借鉴。     

肠道菌群在脊髓损伤后胃肠道炎症反应中的研究进展

脊髓损伤(spinal cord injury, SCI)目前尚无有效的治疗手段。脊髓损伤后,患者常伴有严重的胃肠功能障碍,严重影响患者的生活质量。研究发现,脊髓损伤后肠道菌群的紊乱和脊髓损伤后的胃肠道功能障碍密切相关。因此,本文围绕脊髓损伤后肠道菌群的变化,探讨肠道菌群在迷走神经、下丘脑-垂体-肾上腺和肠道菌群代谢物3个途径中发挥的作用,及与胃肠道炎症反应相关的研究进展。     

汉族ABO血型的皮纹特征分析

作者对芜湖地区３８２例（男２２０人;女１６２人）汉族ＡＢＯ血型的皮纹特征进行了分析,其中Ｏ型１３０人,Ａ型１１３人,Ｂ型１０１人,ＡＢ型３８人。分析比较了指纹类型、指纹组合格局、指嵴纹计数、掌嵴纹计数、ａｔｄ角,掌部真实花纹,掌褶纹和拇趾球纹等项参数,结果表明,ＡＢＯ各血型的皮纹参数间有若干统计学差异。     

模拟四季温度层积对南方红豆杉种子生理性状的影响

为了解濒危物种南方红豆杉(Taxus chinensis var. mairei)种子内含物含量受温度和湿度层积的影响,设置4个季节、2种湿度(16%和24%)基质层积处理,对种子的可溶性糖、淀粉、可溶性蛋白和脂肪等内含物质的变化进行研究。结果表明,不同层积处理下种子贮藏物质的含量有显著变化,春季层积9个月后,可溶性蛋白含量达到最高值;可溶性糖含量呈现降低-升高-降低的变化趋势;淀粉和脂肪含量均随层积逐渐减少。秋季层积9个月后,淀粉含量降至最低。相比于24%湿度,16%湿度的春季、秋季、冬季层积9个月后,脂肪含量均减少较多,说明16%湿度下种子代谢活动更强。春季和秋季的暖温更能促进种子代谢,促进种子形态后熟。夏季温度过高,导致种子生活力下降,夏季层积处理3个月后,种子已经发霉和腐烂。层积过程中,种子内含物在相关酶的作用下,降解为可溶性蛋白、可溶性糖等,为种子萌发提供物质与能量。种子层积时间、温度和湿度及交互作用可作为种子内含物的调控因子。     

栽培稻杂种不育性的遗传研究——Ⅲ.不同类型品种F_1花粉不育性的等位基因分化

以台中65等基因F_1不育系为遗传测验种,测定了栽培稻(O.sativa)45个品种在3个F_1不育基因座的基因型和等位基因的分化度。在S-E3基因座上,除Dular带有S_i/S_i基因型外,其余被测品种均带有S_i/S_i基因型。在S-E2和S-E5基因座上,籼型品种带有高频率的S_i基因,而粳型品种带有高频率的S_i基因。S_i和S_i均具有不同的分化度。籼型品种携带的S_i基因和粳型品种携带的S_i基因具有较高的分化度。中间型品种和广亲和品种的等位基因分化在S-E2基因座上与粳型品种相似,而在S-E5基因座上与籼型品种相似。此外,分析了各类型品种相互杂交F_1杂种在S-E2和S-E5基因座的杂合率、杂合度和杂合性。与籼/粳杂种相比,中间型品种(包括广亲和品种)与籼型和粳型品种杂交,F_1杂种均具有较低的平均杂合性,从而表现出较高的亲和性。因此,无论是杂种不育性还是杂种亲和性均由花粉不育基因控制。花粉不育基因也称为特异亲和基因。     

ent-Pimarane Diterpenes from the Aerial Parts of Siegesbeckia pubescens

Five new ent-pimarane diterpenes ( 1 – 5 ) and five known analogs ( 6 – 10 ) were isolated from the aerial parts of Siegesbeckia pubescens. Their structures, including absolute configurations, were determined by comprehensive spectroscopic methods especially 1D and 2D NMR and quantum chemical electronic circular dichroism calculations. All the isolated compounds were evaluated for their cytotoxicity against human BT549, A549 and H157 cancer cell lines. Among them, compounds 1 and 2 showed mild cytotoxicity against lung cancer cell lines H157 with IC₅₀ values of 16.35±2.59 and 18.86±4.83 μM, respectively.