Photothermal therapy (PTT), a local heating photothermal effect induced by a near-infrared (NIR) laser irradiation, is a promising method for ablating tumors with poorly vascularized microenvironment. [1] The local heating with a high temporal and spatial control can be realized by using an NIR light Transition metal dichalcogenide (TMD) nanomaterials, specially MoS 2 , are proven to be appealing nanoagents for photothermal cancer therapies. However, the impact of the crystal phase of TMDs on their performance in photoacoustic imaging (PAI) and photothermal therapy (PTT) remains unclear. Herein, the preparation of ultrasmall single-layer MoS 2 nanodots with different phases (1T and 2H phase) is reported to explore their phasedependent performances as nanoagents for PAI guided PTT in the second near-infrared (NIR-II) window. Significantly, the 1T-MoS 2 nanodots give a much higher extinction coefficient (25.6 L g −1 cm −1) at 1064 nm and subsequent photothermal power conversion efficiency (PCE: 43.3%) than that of the 2H-MoS 2 nanodots (extinction coefficient: 5.3 L g −1 cm −1 , PCE: 21.3%). Moreover, the 1T-MoS 2 nanodots also give strong PAI signals as compared to negligible signals of 2H-MoS 2 nanodots in the NIR-II window. After modification with polyvinylpyrrolidone, the 1T-MoS 2 nanodots can be used as a highly efficient agent for PAI guided PTT to effectively ablate cancer cells in vitro and tumors in vivo under 1064 nm laser irradiation. This work proves that the crystal phase plays a key role in determining the performance of nanoagents based on TMD nanomaterials for PAI guided PTT.

To reduce cadmium (Cd) pollution of food chains, screening and breeding of low-Cd-accumulating cultivars are the focus of much study. Two previously identified genotypes, a low-Cd-accumulating genotype (LAJK) and a high-Cd-accumulating genotype (HAJS) of pakchoi (Brassica chinesis L.), were stressed by Cd (12.5 μM) for 0 h (T0), 3 h (T3) and 24 h (T24). By comparative transcriptome analysis for root tissue, 3005 and 4343 differentially expressed genes (DEGs) were identified in LAJK at T3 (vs T0) and T24 (vs T3), respectively, whereas 8677 and 5081 DEGs were detected in HAJS. Gene expression pattern analysis suggested a delay of Cd responded transcriptional changes in LAJK compared to HAJS. DEG functional enrichments proposed genotype-specific biological processes coped with Cd stress. Cell wall biosynthesis and glutathione (GSH) metabolism were found to involve in Cd resistance in HAJS, whereas DNA repair and abscisic acid (ABA) signal transduction pathways played important roles in LAJK. Furthermore, the genes participating in Cd efflux such as PDR8 were overexpressed in LAJK, whereas those responsible for Cd transport such as YSL1 were more enhanced in HAJS, exhibiting different Cd transport processes between two genotypes. These novel findings should be useful for molecular assisted screening and breeding of low-Cd-accumulating genotypes for pakchoi.

Cadmium (Cd) is a highly toxic heavy metal and has spread widely in the environment in recent decades. This review summarizes current knowledge about Cd contamination of leafy vegetables, its toxicity, exposure, health risks, and approaches to reducing its toxicity in humans. Leafy vegetable consumption has been identified as a dominant exposure pathway of Cd in the human body. An overview of Cd pollution in leafy vegetables as well as the main sources of Cd is given. Notable estimated daily intakes and health risks of Cd exposure through vegetable consumption for humans are revealed in occupational exposure areas and even in some reference areas. Vegetable consumption is one of the most significant sources of exposure to Cd, particularly in occupational exposure regions. Therefore, numerous approaches have been developed to minimize the accumulation of Cd in leafy vegetables, among which the breeding of Cd pollution-safe cultivars is one of the most effective tools. Furthermore, dietary supplements from leafy vegetables perform positive roles in alleviating Cd toxicity in humans with regard to the effects of essential mineral elements, vitamins and phytochemicals taken into the human body via leafy vegetable consumption.

A low-shoot-Cd (QLQ) and a high-shoot-Cd cultivar (T308) of water spinach (Ipomoea aquatica Forsk.) were used to investigate molecular mechanism of the genotype difference in cadmium (Cd) accumulation. RNA-Seq under 9 and 72 h cadmium exposures (5 mg L(-1)) were undertaken to explore Cd induced genotype differences in molecular processes. In total, 253 747 540 clean reads were assembled into 57 524 unigenes. Among them, 6136 and 10 064 unigenes were differentially expressed in QLQ and T308, respectively. Cell wall biosynthesis genes, such as GAUT and laccase, and three Cd efflux genes (Nramp5, MATE9, and YSL7) had higher expression levels in QLQ, while the genes in sulfur and glutathione metabolism pathway, e.g., sulfate transporter and cysteine synthase, showed higher expression levels in T308. These findings would be useful for further understanding of the mechanisms related to genotype-dependent Cd accumulation and developing the molecular assisted screening and breeding of low-shoot-Cd cultivars for water spinach.