Fluorescence "on-off-on" Assay of Copper Ions and EDTA Using Amino-Functionalized Graphene Quantum Dots.

Copper is an important trace element involved in several physiological processes. The deficiency or excess of Cu in the human body may cause some serious diseases. EDTA has been widely employed in many industry fields owing to its excellent chelating ability. The poor biodegradability of EDTA makes itself a persistent substance in the natural environment. This work provided a fluorescence "on-off-on" strategy for the sequential determination of trace Cu2+ and EDTA. Amino-functionalized graphene quantum dots (afGQDs) were synthetized via the thermal pyrolysis of citric acid. Fluorescence resonance energy transfer (FRET) between afGQDs and 1-(2-pyridylazo)-2-naphthol (PAN) effectively quenched the fluorescence of this carbon-based nanomaterial. The generation of the Cu2+-PAN complex caused the increased FRET efficiency and the further fluorescence decline. The change of the fluorescence intensity sensitively responded to copper ions. The linear range and the limit of detection (LOD) were 1 nM-10 µM and 0.87 nM, respectively. EDTA could decompose the Cu2+-PAN complex and liberate PAN, which weakened the FRET efficiency and led to the fluorescence recovery. The increasing degree of the fluorescence intensity was closely related to EDTA within a concentration range from 10 nM to 10 µM with a LOD at 4 nM. Copper ions in the water and human serum samples and EDTA in the trypsin-EDTA sample were successfully detected based on the proposed fluorescence method.

Ultrasensitive determination of mercury ions using a glassy carbon electrode modified with nanocomposites consisting of conductive polymer and amino-functionalized graphene quantum dots.

A one-pot method based on cyclic voltammetric scan was used to fabricate a glassy carbon electrode modified with nanocomposites consisting of poly(thionine) and amino-functionalized graphene quantum dots (afGQDs). Under near-neutral conditions, the dye polymer was effectively oxidized by hydroxyl radicals (·OH) that were derived from the copper-catalyzed Fenton-like reaction, and the cathodic peak current on the modified electrode greatly increased. The reaction of Cu2+ with thiourea (TU) and the generation of a complex, CuTU2+, led to the decrease of Cu2+/Cu+ species, which inhibited the Fenton-like reaction and reduced the electrochemical response change. Due to a displacement reaction, the addition of Hg2+ into the H2O2-Cu2+-TU system resulted in the release of cuprous ions that benefited the Fenton-like reaction. Under the following optimal conditions: 6 mg mL-1 afGQDs and the 25-cycle potential cycling for the fabrication of the modified electrode, pH 6.5, and the [Formula: see text] ratio of 1.0, the increasing extent of the cathodic peak current exhibited a good linear response to the logarithm of the Hg2+ concentration in the range of 1 pM-1 µM with a detection limit of 0.6 pM. Mercury ions in a water sample were determined with good recovery, ranging from 97 to 103%. The investigation on the uptake of Hg2+ into human vascular endothelial cells, HUVEC, shows that the cells incubated in the high-concentration glucose medium absorbed more mercury ions than HUVEC incubated in the normal medium. As a result, Hg2+ could lead to the greater damage to the former. Graphical abstract.

Identification of differentially expressed lncRNAs and mRNAs in luminal-B breast cancer by RNA-sequencing.

BACKGROUND: Luminal B cancers show much worse outcomes compared to luminal A. This present study aims to screen key lncRNAs and mRNAs correlated with luminal-B breast cancer. METHODS: Luminal-B breast cancer tissue samples and adjacent tissue samples were obtained from 4 patients with luminal-B breast cancer. To obtain differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) between luminal-B breast cancer tumor tissues and adjacent tissues, RNA-sequencing and bioinformatics analysis were performed. Functional annotation of DEmRNAs and protein-protein interaction networks (PPI) construction were performed. DEmRNAs transcribed within a 100 kb window up- or down-stream of DElncRNAs were searched, which were defined as cis nearby-targeted DEmRNAs of DElncRNAs. DElncRNA-DEmRNA co-expression networks were performed. The mRNA and lncRNA expression profiles were downloaded from The Cancer Genome Atlas (TCGA) database to validate the expression patterns of selected DEmRNAs and DElncRNAs. RESULTS: A total of 1178 DEmRNAs and 273 DElncRNAs between luminal-B breast cancer tumor tissues and adjacent tissues were obtained. Hematopoietic cell lineage, Cytokine-cytokine receptor interaction, Cell adhesion molecules (CAMs) and Primary immunodeficiency were significantly enriched KEGG pathways in luminal-B breast cancer. FN1, EGFR, JAK3, TUBB3 and PTPRC were five hub proteins of the PPI networks. A total of 99 DElncRNAs-nearby-targeted DEmRNA pairs and 1878 DElncRNA-DEmRNA co-expression pairs were obtained. Gene expression results validated in TCGA database were consistent with our RNA-sequencing results, generally. CONCLUSION: This study determined key genes and lncRNAs involved in luminal-B breast cancer, which expected to present a new avenue for the diagnosis and treatment of luminal-B breast cancer.

[Transcriptome analysis for leaves of five chemical types in Cinnamomum camphora].

Camphor tree (Cinnamomum camphora) is a representative species in Lauraceae family, and can be subdivided into five types: linalool, camphor, cineol, iso-nerolidol and borneol. In this paper, the leaves transcriptomes of Cinnamomum camphora were sequenced with the platform of Illumina HiSeq™ 2000. Based on the GO (Gene Ontology), COG (Clusters of Orthologous Groups), and KEGG (Kyoto Encyclopedia of Genes and Genomes) database, the function classification, pathway annotation, and the coding sequence prediction of all-Unigenes were carried out. 156 278 Unigenes with an average length of 584 bp and N50 (N50 value is defined as the Unigene length where half the assembly is represented by Unigenes of this size or longer) of 1 023 bp were generated by de novo assembly. A total of 5 5955 Unigenes (35.80%) were annotated through similarity comparison, in which 24 717 and 21 806 Unigenes were assigned into GO and COG, respectively. By searching KEGG database, 3 350 Unigenes were involved in biosynthesis of secondary metabolites, in which 424 Unigenes were involved in monoterpenoids, diterpenoids, sesquiterpenoids, and terpenoid backbone biosynthesis. The analysis of monoterpenoids biosynthesis pathway showed that 9 Unigenes likely encode (+)-linalool synthase, and their expression levels were higher in linalool type but lower in cineole type. This study provides a foundation for further characterizing the functional genes in C. camphora.

[Studies on pharmacological activity of borneol].

Borneol is a major component of many medicinal plant essential oils, as well as a popular traditional Chinese medicine. This essay collects the results of the latest domestic and foreign studies, and summarizes and analyzes its activity and reaction mechanism on analgesia, putridity elimination and flesh regeneration, and repair of damaged cells. Moreover, it proposes problems concerning borneol during medical studies, providing support for the in-depth study and exploration of efficacies of precious traditional Chinese medicines as well as the effective utilization and development of innovative medicines.

Chromosome-level genome assembly and resequencing of camphor tree (Cinnamomum camphora) provides insight into phylogeny and diversification of terpenoid and triglyceride biosynthesis of Cinnamomum.

Cinnamomum species attract attentions owing to their scents, medicinal properties, and ambiguous relationship in the phylogenetic tree. Here, we report a high-quality genome assembly of Cinnamomum camphora, based on which two whole-genome duplication (WGD) events were detected in the C. camphora genome: one was shared with Magnoliales, and the other was unique to Lauraceae. Phylogenetic analyses illustrated that Lauraceae species formed a compact sister clade to the eudicots. We then performed whole-genome resequencing on 24 Cinnamomum species native to China, and the results showed that the topology of Cinnamomum species was not entirely consistent with morphological classification. The rise and molecular basis of chemodiversity in Cinnamomum were also fascinating issues. In this study, six chemotypes were classified and six main terpenoids were identified as major contributors of chemodiversity in C. camphora by the principal component analysis. Through in vitro assays and subcellular localization analyses, we identified two key terpene synthase (TPS) genes (CcTPS16 and CcTPS54), the products of which were characterized to catalyze the biosynthesis of two uppermost volatiles (i.e. 1,8-cineole and (iso)nerolidol), respectively, and meditate the generation of two chemotypes by transcriptional regulation and compartmentalization. Additionally, the pathway of medium-chain triglyceride (MCT) biosynthesis in Lauraceae was investigated for the first time. Synteny analysis suggested that the divergent synthesis of MCT and long-chain triglyceride (LCT) in Lauraceae kernels was probably controlled by specific medium-chain fatty acyl-ACP thioesterase (FatB), type-B lysophosphatidic acid acyltransferase (type-B LPAAT), and diacylglycerol acyltransferase 2b (DGAT 2b) isoforms during co-evolution with retentions or deletions in the genome.

Investigation of photo-induced electron transfer between amino-functionalized graphene quantum dots and selenium nanoparticle and it's application for sensitive fluorescent detection of copper ions.

Copper ions play an essential role in some biological processes. Currently, there is a need for the development of convenient and reliable analytical methods for the Cu2+ measurement. In the present work, a sensitive fluorescence method was developed for the determination of copper ions. Amino-functionalized graphene quantum dots (af-GQDs) and selenium nanoparticles (Se NPs) were synthetized, respectively, and they were characterized via transmission electron microscope, infrared spectrum analysis and X-ray photoelectron spectrum measurement. Photo-induced electron transfer (PET) between the prepared two nanomaterials could effectively quench the fluorescence of af-GQDs. Cu(II) was reduced to Cu(I) in the presence ascorbic acid and Cu2Se was finally generated on Se NPs surface, which led to the declined PET efficiency and inhibited the fluorescence quenching of af-GQDs. The change in fluorescence intensity was linearly correlated to the logarithm of the Cu2+ concentration from 1 nM to 10 µM, with a detection limit of 0.4 nM under the optimal conditions. The detections of copper ions in water samples were realized via standard addition method and the recovery values varied from 98.7% to 103%. The proposed fluorescence method was also employed to analyze the uptake of Cu2+ into human cervical carcinoma HeLa cells and cisplatin-resistant HeLa cells (HeLa/DDP cells). The experimental results indicate that the decreased hCTR1 expression level in HeLa/DDP cells weakened the uptake of copper ions into these drug-resistant tumor cells.

Voltammetric determination of reduced glutathione using poly(thionine) as a mediator in the presence of Fenton-type reaction.

An indirect and sensitive electrochemical method for the determination of reduced glutathione (GSH) was developed by using poly(thionine) (PTH) as a mediator in the presence of Fenton-type reaction on the electrode surface in this work. Cyclic voltammetry and the adsorption of Cu2+ were employed in sequence to fabricate a Cu-PTH modified electrode, which was characterized by scanning electron microscopy, XPS and electrochemical measurements. Hydroxyl radicals that were derived from the Fenton-type reaction between Cu2+ and H2O2 could effectively oxidize PTH, leading to the great enhancement of the cathodic peak current of the dye polymer in the cyclic voltammetric scan. The electroreduction of PTH on the electrode surface was found to be inhibited in the presence of GSH. Under the optimized conditions, the cathodic peak current change was found to be proportional to the logarithm of the GSH concentration from 10nM to 1mM with a detection limit of 2.5nM estimated at a signal-to-noise ratio of 3. The proposed electrochemical sensor was successfully employed for the determination of GSH in real samples with satisfactory results.

Identification and expression analysis of twenty ARF genes in Populus.

The auxin response factor (ARF) family of transcription factors is a crucial component of auxin signaling and plays important roles regulating numerous growth and developmental processes in plants. We isolated and characterized 20 ARF genes involved in adventitious root development of Populus. Multiple protein sequence alignments revealed that the PeARF proteins contained a highly conserved region in their N-terminal portion corresponding to the DNA-binding domain of the Arabidopsis ARF family. Except for PeARF3.1, PeARF3.2, PeARF17.1 and PeARF17.2, the PeARF proteins contained a carboxyl-terminal domain related to the Arabidopsis domains III and IV, which are involved in homo- and heterodimerization. The exon-intron structures of the PeARF genes were determined by aligning cDNA and genomic sequences. As expected, most PeARF genes had a similar distribution of exon-intron structures. Temporal expression patterns of these genes were profiled during adventitious root development. All 20 PeARF genes were expressed in root, stem and leaf in a dynamic manner. Transient expression assays with Populus protoplasts demonstrated that these PeARFs were localized to the nucleus. These results suggest that PeARFs may play diverse regulatory roles in adventitious root development of Populus and contribute to improving our understanding of conserved and divergent aspects of auxin signaling in various species.