Hydrocracking of Jatropha oil to aromatic compounds over the LaNiMo/ZSM-5 catalyst

The conversion of biomass to produce high-valued chemical aromatic intermediates such as benzene (B), toluene (T), ethylbenzene (E), xylene (X), naphthalene (N) has attached booming interests. Herein, in order to obtain BTEXN aromatics on the hydrocracking of Jatropha oil, several LaNiMo/ZSM-5 catalysts (La loading from 0.5 to 15 wt%) by alkali treatment and metal impregnation methods were synthesized and investigated. Fundamentally, we found the alkali treatment engendered more mesoporosity to ZSM-5 and resulted in higher catalytic activity. It bears emphasis that further metal impregnated catalyst NiMo/ZSM-5 could improve the aromatics yield due to the increase of metal active sites and acidity sites. Besides, we noted that La loading had positive effects on coke reduction, catalytic stability and catalyst lifetime. To sum up, results confirmed the favorable 1 wt% La–NiMo/ZSM-5 had maximum 75 wt% BTEXN yield, longer catalyst lifetime for 100 h and decreased carbon deposits by 1.11%.     

PcNRAMP1 Enhances Cadmium Uptake and Accumulation in Populus × canescens

Poplars are proposed for the phytoremediation of heavy metal (HM) polluted soil. Characterization of genes involved in HM uptake and accumulation in poplars is crucial for improving the phytoremediation efficiency. Here, Natural Resistance-Associated Macrophage Protein 1 (NRAMP1) encoding a transporter involved in cadmium (Cd) uptake and transport was functionally characterized in Populus × canescens. Eight putative PcNRAMPs were identified in the poplar genome and most of them were primarily expressed in the roots. The expression of PcNRAMP1 was induced in Cd-exposed roots and it encoded a plasma membrane-localized protein. PcNRAMP1 showed transport activity for Cd²⁺ when expressed in yeast. The PcNRAMP1-overexpressed poplars enhanced net Cd²⁺ influxes by 39–52% in the roots and Cd accumulation by 25–29% in aerial parts compared to the wildtype (WT). However, Cd-induced biomass decreases were similar between the transgenics and WT. Further analysis displayed that the two amino acid residues of PcNRAMP1, i.e., M236 and P405, play pivotal roles in regulating its transport activity for Cd²⁺. These results suggest that PcNRAMP1 is a plasma membrane-localized transporter involved in Cd uptake and transporting Cd from the roots to aerial tissues, and that the conserved residues in PcNRAMP1 are essential for its Cd transport activity in poplars.     

SERS-based Au@Ag core-shell nanoprobe aggregates for rapid and facile detection of lead ions

The public is seriously at risk for major health problems due to environment contamination from lead ions (Pb²⁺) and heavy metal bioaccumulation in agricultural goods. In this study, core-shell silver-coated gold nanorods (Au@Ag NRs) were created and treated with glutathione (GSH) and 4-aminobenzoic acid (4-MBA) to monitor Pb²⁺ using the surface-enhanced Raman scattering (SERS) technique. Its free carboxyl groups can chelate Pb²⁺ added in solution and then present self-aggregated, bringing about more “hot spots” to acquire the significant enhancement signal of 4-MBA. The SERS intensity had a good linear correlation (y = 2420.81x+11333.62, R² = 0.9914) in the dynamic range of Pb²⁺ concentration of 0.5–1000 μg/L under the current optimization conditions, and LOD was 0.021 μg/L. In addition, recoveries of 94.17–101.12% and 81.31–97.86% for Pb²⁺ in tea powder and glutinous rice flour confirmed the monitoring accuracy of Pb²⁺, highlighting its huge potential in the monitoring food quality and safety.     

基于咖啡酸的高灵敏性水合肼荧光探针的合成及应用

以天然产物咖啡酸为原料，设计合成了一种可快速识别水合肼（N2H4）的咖啡酰基荧光探针ED。通过1HNMR、13CNMR和HRMS对其结构进行了表征。通过荧光光谱法研究发现探针ED对N2H4具有高选择和高灵敏性识别，检测过程中检测极限为0.31 μmol/L，最适pH范围为3~8，响应时间为48 s。通过MS和1HNMR证明探针ED对N2H4的荧光响应过程中结构中不饱和酮结构与N2H4反应后生成吡唑环。此外，探针ED与N2H4作用后溶液颜色从无色变为黄色，可实现N2H4的“裸眼检测”，并成功用于水样中N2H4的检测。 关键词：咖啡酸；荧光探针；水合肼；快速识别；检测试纸