煤系石墨鉴定指标探讨

在吉林磐石、湖南郴州、湖南新化、福建永安、福建大田、陕西凤县、内蒙古巴音淖尔等地开展典型煤系石墨矿床野外调查采样和分析测试基础上,探讨煤系石墨鉴定指标。XRD(晶格间距d_(002))是鉴定煤系石墨的可靠指标,Raman(R_(2))是鉴定煤系石墨的辅助指标;煤系石墨的鉴定指标:煤系石墨(d_(002)=0.3354~0.338nm,R_(2)≤0.55)、煤系半石墨(d_(002)=0.338~0.344nm,R_(2)≤0.65),当XRD参数与Raman参数不一致时应以XRD参数为准。

Single-cell Raman and functional gene analyses reveal microbial P solubilization in agriculture waste-modified soils

Application of agricultural waste such as rapeseed meal(RM)is regarded as a sustainable way to improve soil phosphorus(P)availability by direct nutrient supply and stimulation of native phosphate‐solubilizing microorganisms(PSMs)in soils.However,exploration of the in situ microbial P solubilizing function in soils remains a challenge.Here,by applying both phenotype‐based single‐cell Raman with D_(2)O labeling(Raman‐D_(2)O)and genotype‐based high‐throughput chips targeting carbon,nitrogen and P(CNP)functional genes,the effect of RM application on microbial P solubilization in three typical farmland soils was investigated.The abundances of PSMs increased in two alkaline soils after RM application identified by single‐cell Raman D_(2)O.RM application reduced the diversity of bacterial communities and increased the abundance of a few bacteria with reported P solubilization function.Genotypic analysis indicated that RM addition generally increased the relative abundance of CNP functional genes.A correlation analysis of the abundance of active PSMs with the abundance of soil microbes or functional genes was carried out to decipher the linkage between the phenotype and genotype of PSMs.Myxococcota and C degradation genes were found to potentially contribute to the enhanced microbial P release following RM application.This work provides important new insights into the in situ function of soil PSMs.It will lead to better harnessing of agricultural waste to mobilize soil legacy P and mitigate the P crisis.

膨大期干旱对温州蜜柑品质形成的影响及复水后树体水分吸收转运规律

以温州蜜柑膨大期果实为材料,设置基质相对含水量为40%、30%和20%的3个胁迫处理,研究干旱对果实品质形成特点和柠檬酸调控相关转录因子表达模式变化;利用氘水(D_(2)O)示踪法明确柑橘干旱复水后的水分吸收运输和分配规律。温州蜜柑果实膨大期干旱严重抑制果实外在品质的形成,干旱胁迫10 d后,果实横径、纵径、单果质量均显著下降,40 d时各处理横、纵径较对照减少18.33%~23.82%,单果质量降低45.17%~48.67%,各干旱处理间无显著差异。各处理干旱胁迫40 d时果实可溶性固形物显著增加47.7%~59.3%,果糖升高63.25%~78.77%,但蔗糖和葡萄糖增量不大,处理间糖组分差异不大。对照果实柠檬酸含量随生长发育逐渐递减,但干旱胁迫20 d后果实中柠檬酸含量显著上升,最高约为对照的2倍,苹果酸显著高于对照14.70%~33.82%,干旱处理间酸组分含量差异不大。干旱胁迫下,调控柠檬酸积累的转录因子基因CitPH3(WRKY)、CitPH4 (MYB)和CitAN1(bHLH)表达量显著上调。复水后,温州蜜柑根系在4~8 h迅速吸水,主茎和多年生茎内的D_(2)O含量在24 h达到最高,果实在24~48 h吸水量趋于稳定。本试验中,干旱持续时长对果实品质形成的影响较大,干旱程度影响较小;干旱胁迫下CitPH3、CitPH4、和CitAN1上调表达促进了柠檬酸积累,可能是导致柑橘果实酸化的重要原因;果实膨大期持续干旱后,需维持24~48 h土壤湿润水分才能较大量运达果实。

维生素D在系统性硬化中的作用

系统性硬化(systemic sclerosis, SSc)是一种具有多种临床表现并伴有多器官受累的结缔组织病,其发病机制主要包括血管病变、免疫功能障碍和纤维化。近年来对维生素D作用不断深入的研究,发现其不仅参与钙磷代谢和骨骼健康,还在多种自身免疫性疾病中发挥着重要的免疫调节功能。本文综述了维生素D在系统性硬化症中相关作用的研究进展。