Simple fluorescence "turn-off" assay for Congo red using commercial 2-aminophthalic acid.

In this work, the fluorescence properties of 2-aminophthalic acid (NH2-BDC) were studied. NH2-BDC possessed excellent optical properties including bright blue emission with maximum emission at 425 nm, a high quantum yield of 38.49% and excellent photostability. And the fluorescence of NH2-BDC could be selectively quenched by Congo red, which was ascribed to the inner filter effect. Accordingly, NH2-BDC was further employed for fluorescence "turn-off" assay of Congo red with a linear range of 0.05-50 µM and a limit of detection of 1.72 µM. And the sensor was used for the detection of Congo red in real water samples with acceptable results.

Improving the surface area of metal organic framework-derived porous carbon through constructing inner support by compatible graphene quantum dots.

Metal-organic frameworks (MOFs) have emerged as promising precursors to prepare porous carbons due to their unique coordination structure with abundant pores and various chemical compositions. However, the structural collapse and pore shrinkage during pyrolysis severely decrease the surface area of the prepared porous carbons. Herein, we propose an inner support strategy to prepare MOF-derived carbons with improved surface area using graphene quantum dots (GQDs) as the compatible frameworks. GQDs with abundant carboxyl groups (-COOH) and rigid structure can uniformly distribute in MOF-5 precursor by coordinating with [Zn4O]6+ clusters and effectively reinforce the carbon skeleton during pyrolysis. Therefore, the rational GQDs embedded MOF-5 derived porous carbon (GMPC-0.35) shows greatly improved specific surface area (1841 m2 g-1) and mesopore volume (1.62 cm3 g-1) than pure MOF-5 derived carbon (1358 m2 g-1, 0.59 cm3 g-1). As an application exemplification, GMPC-0.35 performs high specific capacitance of 200 F g-1 at 1 A g-1 and good capacitance retention of 53% at 100 A g-1 as the electrode material for supercapacitors, which are higher than most of the reported MOF-5 derived carbons. Therefore, the compatible GQDs support is promising for preparing functional MOF-derived carbon materials.

Prognostic value of LAT-1 status in solid cancer: A systematic review and meta-analysis.

BACKGROUND: The expression of the L-type amino acid transporter 1 (LAT1) plays a significant role in tumor progression. However, it remains unclear whether high LAT1 expression correlates with poor prognosis of solid tumor patients. Here, we conducted a meta-analysis to assess the potential of LAT1 in predicting the prognosis of tumor patients. METHODS AND FINDINGS: A total of 4,579 cases were analyzed from 35 qualified studies. In patients with solid tumors, elevated expression of LAT1 is associated with poor prognosis (overall survival [OS]: pooled hazard ratio (HR) = 1.848, 95% confidence interval (CI) = 1.620-2.108, P < 0.001; disease free survival [DFS]: pooled HR = 1.923, 95% CI = 1.585-2.333, P < 0.001; progression free survival [PFS]: pooled HR = 1.345, 95% CI = 1.133-1.597, P = 0.001). Furthermore, in subgroup analysis, we found an association between high LAT1 expression and poor OS in non-small cell lung cancer (HR = 1.554, 95% CI = 1.345-1.794, P < 0.001), pancreatic cancer (HR = 2.052, 95% CI = 1.613-2.724, P < 0.001) and biliary tract cancer (HR = 2.253, 95% CI = 1.562-3.227, P < 0.001). CONCLUSION: The results of this meta-analysis indicate the reliability and potential of using LAT1 expression as a predictive biomarker in solid cancers prior to treatment. However, further studies with larger sample sizes would be beneficial for fully evaluating the predictive value of LAT1 expression for clinical applications.

Graphene Quantum Dot Reinforced Electrospun Carbon Nanofiber Fabrics with High Surface Area for Ultrahigh Rate Supercapacitors.

High surface area, good conductivity, and high mechanical strength are important for carbon nanofiber fabrics (CNFs) as high-performance supercapacitor electrodes. However, it remains a big challenge because of the trade-off between the strong and continuous conductive network and a well-developed porous structure. Herein, we report a simple strategy to integrate these properties into the electrospun CNFs by adding graphene quantum dots (GQDs). The uniformly embedded GQDs play a crucial bifunctional role in constructing an entire reinforcing phase and conductive network. Compared with the pure CNF, the GQD-reinforced activated CNF exhibits a greatly enlarged surface area from 140 to 2032 m2 g-1 as well as a significantly improved conductivity and strength of 5.5 and 2.5 times, respectively. The mechanism of the robust reinforcing effect is deeply investigated. As a freestanding supercapacitor electrode, the fabric performs a high capacitance of 335 F g-1 at 1 A g-1 and extremely high capacitance retentions of 77% at 100 A g-1 and 45% at 500 A g-1. Importantly, the symmetric device can be charged to 80% capacitance within only 2.2 s, showing great potential for high-power startup supplies.

Predicting the Prognosis of Gastric Cancer by Albumin/Globulin Ratio and the Prognostic Nutritional Index.

Background: Albumin-to-globulin ratio (AGR) and the prognostic nutrition index (PNI) are used to assess the nutritional status and severity of disease for a cancer patient. However, the clinical significance of combining these two predictors in gastric cancer (GC) remains unclear. This study evaluated the prognostic value of pretreatment serum AGR and the PNI for GC.Methods: A total of 273 patients with GC, diagnosed between January 2010 and January 2014, were enrolled. The association of AGR, PNI with clinicopathological characters and prognosis were assessed by Cox regression and Kaplan-Meier methods.Results: Both low AGR group and low PNI group had poor overall survival (OS) and progression-free survival (PFS) (all p < 0.001), while patients with low AGR and PNI had the lowest OS rate. Multivariate analyses revealed that AGR (for OS HR = 0.657, 95%CI: 0.449-0.962, p = 0.031; for PFS HR = 0.684, 95%CI: 0.528-0.895, p = 0.035) was an independent prognostic factor for OS and PFS in patients with GC, and PNI was verified as a predictor for OS (HR = 0.782, 95%CI: 0.503 -0.997, p = 0.048).Conclusions: Low level of pretreatment AGR and PNI may be independent prognostic factors for patients with GC, and patients with both factors indicated the worst OS.

Understanding the structural transformation of carbon black from solid spheres to hollow polyhedra during high temperature treatment.

Understanding the structural transformation of carbon black during high temperature treatment and the underlying mechanism are very important because of the correlation with nanocarbon species such as fullerenes and carbon onions. Herein, we find that carbon black nanoparticles exhibit a solid skin-core structure constructed from small graphene flakes. The skin shows a more ordered structure than the core. During heating treatment in an inert atmosphere, the small graphene flakes coalesce together to form large-area lamellae at 1600 °C. Then, the solid spherical nanoparticles completely transform to hollow polyhedra at 1800 °C with significantly improved crystallinity. What's more, the inner cores of carbon black can be removed through simple oxidation in air, demonstrating that the cores are more disordered and reactive than the skin. Accordingly, the structural transformation mechanism is ascribed to well-ordered graphitic shells being preferentially formed by coalescing ordered small graphene flakes in the skin region of carbon black nanoparticles. The multilocular hollow structure is subsequently formed by reconstruction of highly disordered and twisted inner cores in a confined space.

Characterization of two odorant binding proteins in Spodoptera exigua reveals functional conservation and difference.

As the first biochemical step of olfactory reception and recognition, odorant binding proteins (OBPs) have been demonstrated to be essential. Considering functional diversities of OBPs within a single species, we here extended the characterization of two other OBPs from Spodoptera exigua, belonging to insect Classic OBPs. With a combination of transcriptome and Rapid Amplification of cDNA End (RACE) approaches, two OBP genes in S. exigua were identified, namely SexiOBP1 and OBP7. Expression pattern analysis revealed that both of them exhibited a distinct expression pattern, where OBP1 was broadly and highly expressed in several tissues including antennae of adults whereas OBP7 was abundant only in the antennae of both sexes, strongly indicative of olfactory roles. Further, binding assays showed that the two SexiOBPs shared a common odorant-response spectrum with considerable affinities to host odorants of acetophenone, farnesol and ß-ionone (Ki<20µM). Specially, OBP1 could strongly bind an insect attractant ß-caryophyllene (Ki=2.76µM) released by maize. Intriguingly, the major sex pheromone of S. exigua, Z9,E12-14:Ac, was the best ligand for OBP7 with Ki value of 7.58µM. Ligand structural analysis revealed that the two SexiOBPs were capable of accommodating different types of ligands in shape and size, possibly implying the plasticity of binding pockets. Ultimately, comparison of binding properties among 10 SexiOBPs including the two OBPs in this study implied a cross-talk in functions, i.e. different OBPs are also suitable to accept some common odorants except for unique ligands. Taken together, this study has provided evidence for their involvements in seeking and orientation of host plants, and meanwhile indicates functional conservation and differences between OBP1 and OBP7 from S. xigua.

Putative pathway of sex pheromone biosynthesis and degradation by expression patterns of genes identified from female pheromone gland and adult antenna of Sesamia inferens (Walker).

The general pathway of biosynthesis and degradation for Type-I sex pheromones in moths is well established, but some genes involved in this pathway remain to be characterized. The purple stem borer, Sesamia inferens, employs a pheromone blend containing components with three different terminal functional groups (Z11-16:OAc, Z11-16:OH, and Z11-16:Ald) of Type-I sex pheromones. Thus, it provides a good model to study the diversity of genes involved in pheromone biosynthesis and degradation pathways. By analyzing previously obtained transcriptomic data of the sex pheromone glands and antennae, we identified 73 novel genes that are possibly related to pheromone biosynthesis (46 genes) or degradation (27 genes). Gene expression patterns and phylogenetic analysis revealed that one desaturase (SinfDes4), one fatty acid reductase (SinfFAR2), and one fatty acid xtransport protein (SinfFATP1) genes were predominantly expressed in pheromone glands, and clustered with genes involved in pheromone synthesis in other moth species. Ten genes including five carboxylesterases (SinfCXE10, 13, 14, 18, and 20), three aldehyde oxidases (SinfAOX1, 2 and 3), and two alcohol dehydrogenases (SinfAD1 and 3) were expressed specifically or predominantly in antennae, and could be candidate genes involved in pheromone degradation. SinfAD1 and 3 are the first reported alcohol dehydrogenase genes with antennae-biased expression. Based on these results we propose a pathway involving these potential enzyme-encoding gene candidates in sex pheromone biosynthesis and degradation in S. inferens. This study provides robust background information for further elucidation of the genetic basis of sex pheromone biosynthesis and degradation, and ultimately provides potential targets to disrupt sexual communication in S. inferens for control purposes.