本文采用日本晴水稻种子为实验材料,通过测量种子萌发相关指标、生理指标,探究纳米二氧化锆对水稻种子萌发和幼苗生长生理的影响.研究结果显示:在纳米二氧化锆溶液浓度为 1 mg·L-1、5 mg·L-1、15 mg·L-1、45 mg·L-1、60 mg·L-1 条件下,水稻种子的发芽率、发芽势与对照组相比无明显变化;发芽指数在浓度为 1 mg·L-1 时明显降低,活力指数在15mg·L-1 时显著上升.处理组的幼苗根长和茎长都有所变长,在5 mg·L-1 浓度时根的长度最长,而茎则在浓度为 45 mg·L-1 时最长.各处理组的纳米二氧化锆对水稻幼苗中的过氧化氢酶活性无明显影响;在浓度为 15mg·L-1 时,过氧化物酶活性达到最大值.此外,实验组的丙二醛(MDA)的含量均有所下降,在 5 mg·L-1 时为最小.因此,一定浓度的纳米二氧化锆对水稻种子的萌发并无明显的影响,但它提高了幼苗的活力指数,可以改善幼苗的生理生化指标,提高幼苗抵抗逆境的能力.

Butyrylcholinesterase (BChE) is an essential human biomarker which is related to liver and neurodegenerative diseases. It is of great significance to develop a fluorescent probe that can image BChE in vitro and in vivo. Unfortunately, most fluorescent probes that are based on a single change in fluorescence intensity are susceptible to environmental interference. Therefore, we reported an easily available ratiometric fluorescent probe, TB-BChE, with aggregation-induced emission (AIE) characteristics for ratiometric imaging of BChE. TB-BChE demonstrated excellent sensitivity (LOD = 39.24 ng mL-1) and specificity for BChE. Moreover, we have successfully studied the ratiometric imaging of TB-BChE to BChE in a nonalcoholic fatty liver disease model. These results indicated that TB-BChE is expected to become a powerful analysis tool for butyrylcholinesterase research in basic medicine and clinical applications.

Here, we report an easily available endoplasmic reticulum-targeting near-infrared fluorescent probe (ER-CE), which can detect esterase in the endoplasmic reticulum and monitor the changes in the esterase amount in tumors in mice in real time. These results indicate that ER-CE is expected to become a powerful analysis tool for the research of endoplasmic reticulum esterase-related diseases.

Triptolide (TP) is one of the most common systemic treatments for inflammatory and immune diseases in China for centuries. However, TP exhibits some disadvantages, such as poor solubility in water, poor bioavailability, liver toxicity, renal toxicity, and other side effects. In order to reduce the adverse effects of TP, researchers have developed numerous strategies to address the adverse properties of triptolide. Nano-carrier-based triptolide delivery systems represent an emerging technology and are one of the strategies of nanomedicine that combines diagnostic and therapeutic applications in a single agent. In this approach, we developed a glutathione-activated carrier-free nanodrug of triptolide (CyssTPN) as a trackable drug delivery system. In this system, CyssTP self-assemble to form a carrier-free nanodrug, which possesses a monodisperse spherical morphology with hydrodynamic average sizes of about 50 nm. In addition, CyssTPN had good stability under different physiological conditions (pH, high salt, etc.). Apart from cellular imaging and cell uptake, CyssTPN can be tracked by the activation of TP ability in real-time and applied for cancer cell treatment efficiently. The result showed that CyssTPN could improve solubility, reduce the side effects, and increase the bioavailability of triptolide. It could also track triptolide activation timely and tumor therapy successfully.

MicroRNAs (miRNAs) are related to many biological processes and regarded as biomarkers of disease. Rapid, sensitive, and specific methods for miRNA assay are very important for early disease diagnostic and therapy. In the present work, an ultrasensitive electrochemical biosensing platform has been developed for miRNA-21 assay by combining CRISPR-Cas13a system and catalytic hairpin assembly (CHA). In the presence of miRNA-21, it would hybridize with the spacer region of Cas13a/crRNA duplex to activate the cleavage activity of CRISPR-Cas13a system, leading to the release of initiator of CHA to generate amplified electrochemical signals. Base on the CRISPR-Cas13a-mediated cascade signal amplification strategy, the developed electrochemical biosensing platform exhibited high sensitivity with a low detection limit of 2.6 fM (S/N = 3), indicating that the platform has great potential for application in early clinical diagnostic.

It is necessary to effectively absorb trace phosphopeptides/proteins from complex phosphopeptide-containing samples for mass spectrometry (MS)-based phosphoproteomics. Here, Bi3+/Fe3+/Zr4+ co-doped TiO2 (TiO2/Bi/Fe/Zr) nanocomposite with a high surface-to-volume ratio was synthesized by sol-gel method for selective enrichment of phosphopeptides. The enrichment ability of this modified TiO2 toward phosphopeptides was evaluated by using standard phosphoproteins and HeLa cell lysate. The results demonstrated that, compared with commercial titanium dioxide for phosphopeptides enrichment, this proposed TiO2/Bi/Fe/Zr nanocomposite has a lower detection limit (4 x 10(-10) M) and higher selectivity at a low weight ratio of phosphopeptides/non-phosphopeptides (1:1000). Additionally, a total of 676 phosphorylation sites were identified from the HeLa cell lysate after enrichment by the TiO2/Bi/Fe/Zr nanocomposite. In brief, the TiO2/Bi/Fe/Zr nanocomposite exhibits better performance on the selectively absorption of phosphopeptides from either simple or complex biological samples, indicating the great potential application in phosphoproteomics study.

It is necessary to effectively absorb trace phosphopeptides/proteins from complex phosphopeptide-containing samples for mass spectrometry (MS)-based phosphoproteomics. Here, Bi3+/Fe3+/Zr4+co-doped TiO2 (TiO2/Bi/Fe/Zr) nanocomposite with a high surface-to-volume ratio was synthesized by sol-gel method for selective enrichment of phosphopeptides. The enrichment ability of this modified TiO2 toward phosphopeptides was evaluated by using standard phosphoproteins and HeLa cell lysate. The results demonstrated that, compared with commercial titanium dioxide for phosphopeptides enrichment, this proposed TiO2/Bi/Fe/Zr nanocomposite has a lower detection limit (4 × 10-10 M) and higher selectivity at a low weight ratio of phosphopeptides/nonphosphopeptides (1:1000). Additionally, a total of 676 phosphorylation sites were identified from the HeLa cell lysate after enrichment by the TiO2/Bi/Fe/Zr nanocomposite. In brief, the TiO2/Bi/Fe/Zr nanocomposite exhibits better performance on the selectively absorption of phosphopeptides from either simple or complex biological samples, indicating the great potential application in phosphoproteomics study.

Fe3+-Enhanced NIR-to-NIR multifunctional upconversion luminescence nanocrystals were synthesized for excellent tumor-targeted UCL/MRI/X-ray trimodal bioimaging.

Novel Bi0.15Fe0.15TiO2 nanocomposites (B0.15F0.15TNs) were synthesized for the first time by a modified sol-gel technology and successfully applied to selective extraction and enrichment of phosphopeptides from digested protein mixture solutions and real samples (tissue protein extract from human liver). The codoping of Bi and Fe into TiO2 results in a significant enhancement in both the enrichment efficiency and selectivity. Compared with the commercial available TiO2 extractant, the proposed B0.15F0.15TNs possess a lower detection limit (2 × 10-9 M) and higher selectivity at a low weight ratio of 1:1200 (phosphopeptides/nonphosphopeptides). Additionally, a total of 223 phosphorylation sites were identified from the human liver lysate after enrichment by the B0.15F0.15TNs. In addition, the synthesis of B0.15F0.15TNs is quite easy, of high yield, and inexpensive.

Lectin receptor-like kinases (LecRKs) play important roles in the responses to adverse environment stress. Abscisic acid (ABA) is a plant hormone involved in plant growth, development and adverse environmental stress responses. Although some studies of ABA response LecRK genes have been reported, the molecular mechanisms of LecRKs regulation of downstream pathways under ABA induction are not well understood. The present study showed that LecRK-VI.4 responded to ABA and negatively regulated stomatal closure. Here, a quantitative phosphoproteomics approach based on mass spectrometry was employed to study the roles of LecRK-VI.4 in the ABA signaling pathway. Metal oxide affinity beads and C18 chromatography were used for phosphopeptide enrichment and separation. The isobaric tags for relative and absolute quantitation were used for profiling the phosphoproteome of mutant lecrk-vi.4-1 and wild-type Col-0 Arabidopsis under normal growth conditions or ABA treatments. In total, 475 unique phosphopeptides were quantified, including 81 phosphopeptides related to LecRK-VI.4 regulation. Gene ontology, protein-protein interaction and motif analysis were performed. The bioinformatics data showed that phosphorylated proteins regulated by LecRK-VI.4 had close relations with factors of stomatal function, which included aquaporin activity, H+ pump activity and the Ca2+ concentration in the cytoplasm. These data have expanded our understanding of how LecRK-VI.4 regulates ABA-mediated stomatal movements.

Multimodal bioimaging, which integrates the merits of two or more imaging techniques, has been applied in clinical prognosis and diagnosis for several years. For in vivo bioimaging, it is important to develop materials with excitation and emission spectra that lie in the “optical transparent biological window” (750–1000 nm), in which there is minimal autofluorescence, little risk of damage to biosamples and deep tissue penetration ability. Herein, folate conjugated core–shell upconversion luminescence (UCL) nanoparticles (NPs), FA-NaYF4:Yb3+,Tm3+,20%Fe3+@NaGdF4 (FA-Y:Yb,Tm,Fe@Gd) NPs, were synthesized and applied for trimodal imaging, i.e. NIR UCL imaging using the Y:Yb,Tm,Fe core, and magnetic resonance and X-ray imaging using the NaGdF4 shell. The folate was incorporated to be used as a tumor-targeting probe. The addition of 20%Fe3+ (in moles) resulted in a 20 times increase in the NIR UCL intensity under 980 nm excitation. The role of the Fe3+ in the enhancement of the NIR UCL efficiency was explored. The methyl thiazolyl tetrazolium (MTT) assay of HeLa cells and the histological analysis of healthy viscera sections showed that the NPs have low biological toxicity.

Lycosin-I is a linear amphipathic α-helical anticancer peptide (ACP) extracted from the spider Lycosa singoriensis, which can activate the mitochondrial death pathway to induce apoptosis in tumor cells and up-regulate p27 to inhibit cell proliferation. However, the applicability of lycosin-I as a novel anticancer drug is limited by its low cellular entry and efficacy in solid tumors. Amino acid substitution presents an effective and modest strategy to improve the anticancer activity and bioavailability of ACPs. Herein, an arginine-modified lycosin-I (named R-lycosin-I) was designed and synthesized by substituting lysine (Lys) with arginine (Arg). This peptide exhibited higher anticancer activity and penetrability against solid tumor cells than lycosin-I. They displayed noticeable differences in their physicochemical properties including the secondary structure, hydrodynamic size, and zeta potential. Fluorescence analyses have confirmed that R-lycosin-I exhibits increased cellular uptake and improved intracellular distribution. Due to its superior physical and chemical properties and high serum stability, R-lycosin-I could penetrate deeply into tumor spheroids and produce strong toxicity in the 3D tumor model. Overall, these findings suggest that arginine modification may provide an effective strategy for improving the anticancer activity of lycosin-I, and R-lycosin-I may be a useful lead for developing anticancer drugs.

Lectin receptor-like kinases (LecRKs) are a class of membrane proteins found in higher plants. They play important roles in defense against of pathogens, perception of insect feeding, and stress tolerance. LecRK-VII.1 (AT4G04960) is one member of the LecRK family, which contains a conserved lectin domain and a kinase domain. In this study, the lecrk-VII.1 mutants (lecrk-VII.1-1 and lecrk-VII.1-2) showed increased seed germination rates and primary root length compared to ecotype Columbia-0 (Col-0) when treated with different concentrations of NaCl and methyl jasmonate (MeJA). To further confirm the possible role of LecRK-VII.1 in salt and jasmonic acid (JA) responses, we performed a comparative proteomic analysis of Arabidopsis Col-0 and lecrk-VII.1-1 mutant seedlings. In total, 312 proteins were differentially expressed of which 75 were related to stress responses including salt stress and JA response. Among them, decreased expressions of lipoxygenase (LOX) and annexin were confirmed by RT-PCR analyses. Activity of LOX was accordingly reduced in lecrk-VII.1 mutants. These results provide some valuable data to understand the role of LecRK-VII.1 in the response to salt stress and MeJA.