Composition and Diversity of Gut Bacterial Community in Different Life Stages of a Leaf Beetle Gastrolina depressa.

Insect gut bacteria have a significant impact on host biology, which has a favorable or negative impact on insect fitness. The walnut leaf beetle (Gastrolina depressa) is a notorious pest in China, causing severe damage to Juglandaceae trees including Juglans regia and Pterocarya rhoifolia. To date, however, we know surprisingly little about the gut microbiota of G. depressa. This study used a high-throughput sequencing platform to investigate the gut bacterial community of G. depressa throughout its life cycle, including the 1st, 2nd, and 3rd instar larvae, as well as male, female, and pre-pregnant female adults. Our results showed that the diversity of the gut bacterial community in larvae was generally higher than that in adults, and young larvae (1st and 2nd larvae) possessed the most diversified and abundant community. Principal coordinate analysis results showed that the gut microbiota of adults cluster together, which is independent of the 1st and 2nd instar larvae. The main phyla were Proteobacteria and Firmicutes in the microbial community of G. depressa, while the dominant genera were Enterobacter, Rosenbergiella, Erwinia, Pseudomonas, and Lactococcus. The gut bacteria of G. depressa were mostly enriched in metabolic pathways (carbohydrate metabolism and amino acid metabolism) as revealed by functional prediction. This study contributes to a better knowledge of G. depressa's gut microbiota and its potential interactions with the host insect, facilitating the development of a microbial-based pest management strategy.

Visual detection of multiple antioxidants based on three chloroauric acid/Au-Ag nanocubes.

A colorimetric sensing method is described for discrimination of multiple antioxidants based on core-shell Au@Ag nanocubes (NCs). In order to extract data-rich colorimetric responses from the sensor array, three different concentrations of chloroaurate acid (HAuCl4) were employed as sensing elements. Interestingly, Au3+ ions can be reduced to different valence states (i.e., Au(0) and Au(I)) by different antioxidants, and thus effectively inhibit the oxidation etching process of Au@Ag NCs by Au(III) ions to varying extents, generating diverse colorimetric responses (color and absorbance). This enables identification of the six antioxidants at 10 nM via linear discriminant analysis (LDA) with relative standard deviation (RSD) of 2.52% (n = 3). The discrimination ability of the sensor array was further evaluated in antioxidant binary and multicomponent mixtures. Remarkably, identification of these six antioxidants spiked in urine was realized with 100% of accuracy. Schematic presentation of colorimetric assay for antioxidants based on three chloroauric acid/Au-Ag nanocubes.

Colorimetric Differentiation of Flavonoids Based on Effective Reactivation of Acetylcholinesterase Induced by Different Affnities between Flavonoids and Metal Ions.

Flavonoids are closely related to human health, and the distinguishiment of flavonoids is an important but difficult issue. We herein unveil a novel colorimetric sensor array for the rapid identification of 7 flavonoids (e.g., gallocatechin (GC), morin hydrate (MH), puerarin (Pu), epigallocatechin gallate (EGCG), catechin (C), rac Naringenin (rN), and Flavone (Fla)) for the first time. The colorimetric performances of gold nanoparticles (AuNPs) are characteristically correlated with thiocholine, which is issued from the enzymatic hydrolysis of acetylcholine (AcCh). Therefore, as a proof-of-concept design, three sensors (Cu2+/acetylcholinesterase (AcChE)/AcCh/AuNPs, Zn2+/AcChE/AcCh/AuNPs, and Mn2+/AcChE/AcCh/AuNPs) were constructed to form our sensor array. The distinct affinities between flavonoids and metal ions would cause varying degrees of effective reactivation of AcChE, leading to unique colorimetric response patterns upon being challenged with the seven flavonoids for their pattern recognition, enabling an excellent identification of the seven flavonoids at a concentration of 20 nM and different concentrations of individual flavonoids, as well as mixtures of them.

Electronic-Tongue Colorimetric-Sensor Array for Discrimination and Quantitation of Metal Ions Based on Gold-Nanoparticle Aggregation.

Sensor arrays, called "electronic tongues", provide an alternative to time-consuming detection approaches. In this work, a colorimetric-sensor array composed of three recognition receptors (cysteine, l-glutathione, and melamine) was developed for fast discrimination of toxic metal ions. Different recognition receptors exhibited different binding affinities toward metal ions, causing diverse gold-nanoparticle (AuNP)-aggregation behaviors and generating distinct colorimetric response patterns. As "fingerprints", these response patterns can be quantitatively analyzed by linear-discriminant analysis (LDA). The sensor array achieved good discrimination of six kinds of metal ions (Ti4+, Cr3+, Mn2+, Fe3+, Pb2+, and Sn4+) in deionized water and real samples. It possessed good reproducibility and exhibited a linear range of 100-900 nM ( R2 = 0.97) for Ti4+, 100-900 nM ( R2 = 0.97) for Cr3+, 100-900 nM ( R2 = 0.98) for Mn2+, 100-1000 nM ( R2 = 0.92) for Sn4+, 100-800 nM ( R2 = 0.94) for Fe3+, and 100-900 nM ( R2 = 0.97) for Pb2+. The sensor array shows feasible potential in environmental monitoring and simplification of water-quality analysis.

Colorimetric Electronic Tongue for Rapid Discrimination of Antioxidants Based on the Oxidation Etching of Nanotriangular Silver by Metal Ions.

We present a simple, rapid, and effe/ctive colorimetric sensor array (or colorimetric electronic tongue) for discrimination of antioxidants, which is based on the oxidation etching of triangular silver nanoparticles (TriAgNPs) by three metal ions (Se2+, Sn4+, and Ni2+) as array's recognition elements and the inhibition of TriAgNP etching by antioxidants. Since highly reactive edges/tips of TriAgNPs are easier to be etched than other regions, the morphology of TriAgNPs undergoes a transition from nanoprism to nanodisk, accompanied by a color change from blue to yellow. The addition of diverse antioxidants inhibits TriAgNP etching in varying degrees, forming different etching morphologies with rainbowlike color. Surface plasmon resonance peak shift (Δλ) values of final TriAgNPs were captured as colorimetric signal outputs for further data processes. Linear discriminant analysis, hierarchical clustering analysis, heat map, etc. were adopted in the further data analysis process, showing the excellent discrimination ability of the sensor array for six antioxidants at 1 nM level. Moreover, selectivity experiments and practical application tests show that our sensor array had considerable selectivity and great potential in real samples.

Novel gene-activated matrix with embedded chitosan/plasmid DNA nanoparticles encoding PDGF for periodontal tissue engineering.

Recently, much attention has been paid to tissue engineering and local gene delivery system in periodontal tissue regeneration. Gene-activated matrix (GAM) blends these two strategies, serving as a local bioreactor with therapeutic gene expression and providing a structural template to fill the lesion defects for cell adhesion, proliferation and synthesis of extracellular matrix (ECM). In this study, we designed a novel GAM with embedded chitosan/plasmid nanoparticles encoding platelet derived growth factor (PDGF) based on porous chitosan/collagen composite scaffold. The chitosan/collagen scaffold acted as three-dimensional carrier and chitosan nanoparticles condensed plasmid DNA. The plasmid DNA entrapped in the scaffolds showed a sustained and steady release over 6 weeks and could be effectively protected by chitosan nanoparticles. MTT assay demonstrated that periodontal ligament cells (PDLCs) cultured into the novel GAM achieved high proliferation. Luciferase reporter gene assay displayed that the novel GAM could express 1.07 x 10(4) LU/mg protein after 1 week and 8.97 x 10(3) LU/mg protein after 2 weeks. The histological results confirmed that PDLCs maintained a fibroblast figure and the periodontal connective tissue-like structure formed in the scaffolds after 2 weeks. Semi-quantitative immunohistochemical results suggested that PDGF protein expressed at a relatively high level after 2 weeks. From this study, it can be concluded that the novel GAM had potential in the application of periodontal tissue engineering.

[Clinical evaluation and comparison of porcelain laminate veneers and computer aided design and computer aided manufacture veneers].

OBJECTIVE: To evaluate the clinical application of a computer aided design and computer aided manufacture (CAD/CAM) veneer system. METHODS: Sixty-five CAD/CAM veneers were made for 23 patients and 105 porcelain veneers were made for 25 patients. After three years, the clinical performance of two veneer systems were evaluated and compared according to modified California Dental Association/Ryge criteria. The clinical success rate and patient satisfactory rate were calculated. RESULTS: The success rates of porcelain veneer and CAD/CAM veneer were 96.2% and 93.8%, respectively. The patient satisfactory rates were 92.4% and 90.8%. There was no significant difference between two veneer systems in color match, marginal discoloration and marginal fit. But the surface texture of CAD/CAM veneers was better than that of porcelain veneers. CONCLUSIONS: CAD/CAM veneer system was a successful approach for veneer restorations.