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For the in-situ treatment process of landscape waters, ponds, reservoirs and other water bodies, there is a significant deviation between the experiment results and the actual treatment effect due to volume amplification effect. Therefore, this study systematically explored the influence of hydraulic conditions, dosing frequency, dosing intervals of coagulant, and coagulant dilution multiples on the removal efficiency of particulate and organic matter on a large scale to precisely simulate the practical treatment situation. Results showed that dosing intervals and dosing frequency played an important role in the aggregation and settling process of particulate matter by influencing the energy barrier between particles, while hydraulic conditions affected the structure and settling characteristics of flocs. The overall trend of the total organic matter was consistent with that of particulate matter. However, only the freshly formed aluminum hydroxide precipitates had adsorption activity to humic substances. The adsorption could be completed rapidly so that hydraulic conditions had no influence on the aggregation process of humic substances. While during stirring and aging process, humic substances was found to be released due to the polymerization and crystallization of aluminum precipitates. From the results of pilot tests, a treatment strategy was implemented for a reservoir in southern China and the ideal treatment effect was achieved. This study provided theoretical foundation and design guidance for the in-situ coagulation treatment of landscape waters, ponds and reservoirs. [Display omitted] [ABSTRACT FROM AUTHOR]

More and more attention has been paid to the aggregation behavior of nanoparticles, but little research has been done on the effect of particle size. Therefore, this study systematically evaluated the aggregation behavior of nano-silica particles with diameter 130–480 nm at different initial particle concentration, pH, ionic strength, and ionic valence of electrolytes. The modified Smoluchowski theory failed to describe the aggregation kinetics for nano-silica particles with diameters less than 190 nm. Besides, ionic strength, cation species and pH all affected fast aggregation rate coefficients of 130 nm nanoparticles. Through incorporating structural hydration force into the modified Smoluchowski theory, it is found that the reason for all the anomalous aggregation behavior was the different structural hydration layer thickness of nanoparticles with various sizes. The thickness decreased with increasing of particle size, and remained basically unchanged for particles larger than 190 nm. Only when the distance at primary minimum was twice the thickness of structural hydration layer, the structural hydration force dominated, leading to the higher stability of nanoparticles. This study clearly clarified the unique aggregation mechanism of nanoparticles with smaller size, which provided reference for predicting transport and fate of nanoparticles and could help facilitate the evaluation of their environment risks. [Display omitted] [ABSTRACT FROM AUTHOR]

• A predator-prey model with nonlinear cross-diffusion is investigated. • The extension of cross diffusion parameters brings new biological significance. • Appearance of Turing instability depends on cross-diffusion negative coefficient. • Bifurcation near trivial and non-trivial equilibrium is derived. • Numerical simulations illustrate and supplement our theoretical analysis. A nonlinear reaction cross-diffusion predator-prey system under Neumann boundary condition is considered. Negative diffusion coefficients with local accumulation effect of prey are introduced. Firstly, the criteria for local asymptotic stability of the positive homogeneous steady state with or without cross-diffusion are discussed. Moreover, the conditions for diffusion-driven instability are obtained and the Turing regions in the plane of cross-diffusion coefficients is achieved. Secondly, the existence and multiplicity of spatially nonhomogeneous/homogeneous steady-state solutions are studied by virtue of the Lyapunov–Schmidt reduction. Finally, to clarify the theoretical results, some numerical simulations are carried out. One of the most interesting finding is that Turing instability in the model is induced by the negative diffusion coefficients. [ABSTRACT FROM AUTHOR]

Denote by B ̇ α , ϕ (Ω) the Orlicz–Besov space, where α ∈ R , ϕ is a Young function and Ω ⊂ R n is a domain. For α ∈ (− n , 0) and optimal ϕ , in this paper we characterize domains supporting the imbedding B ̇ α , ϕ (Ω) into L n ∕ | α | (Ω) via globally n -regular domains. This extends the known characterizations for domains supporting the Besov imbedding B ̇ p p s (Ω) into L n p ∕ (n − s p) (Ω) with s ∈ (0 , 1) and 1 ≤ p < n ∕ s. The proof of the imbedding B ̇ α , ϕ (Ω) → L n ∕ | α | (Ω) in globally n -regular domains Ω relies on a geometric inequality involving ϕ and Ω , which extends a well-known geometric inequality of Caffarelli, Savin and Valdinoci. [ABSTRACT FROM AUTHOR]

In order to evaluate the influence of particle size and particle concentration on the coagulation process, two kinds of particle suspensions, nanoparticles and microparticles, were employed to investigate the effect of particle size on coagulation mechanisms with varying coagulation parameters. Results showed that it is easier for nanoparticles to cause self-aggregation because of Brownian motion, while interception and sedimentation are the mainly physical processes affecting particle transport for microparticles, so they are more stable and disperse more easily. The particle size distribution and particle concentration had distinct influence on the coagulation mechanisms. Under neutral conditions, as the amount of coagulant increased, the coagulation mechanism for nanoparticles changed from charge neutralization to sweep flocculation and the nanoparticles became destabilized, re-stabilized and again destabilized. For microparticles, although the coagulation mechanism was the same as that of nanoparticles, the increased rate of aluminum hydroxide precipitation exceeded the adsorption of incipiently formed soluble alum species, resulting in the disappearance of the re-stabilization zone. Under acidic conditions, Brownian motion dominates for nanoparticles at low particle concentrations, while sweep flocculation is predominant at high particle concentrations. As for microparticles, charge neutralization and sweep flocculation are the mechanisms for low and high particle concentrations respectively. Under alkaline condition, although the mechanisms for both nano- and microparticles are the same, the morphology of flocs and the kinetics of floc formation are different. At low particle concentrations, nanoparticles have larger growth rate and final size of flocs, while at high particle concentrations, nanoparticles have higher fractal dimension and recovery factors. Unlabelled Image [ABSTRACT FROM AUTHOR]

Graphene shows great promise as a high-efficiency electrothermal film for flexible transparent defoggers/defrosters. However, it remains a great challenge to achieve a good balance between the production cost and the properties of graphene films. Here, we proposed a cost-effective self-assembly method to fabricate high-performance, large-area graphene oxide/electrochemically exfoliated graphene hybrid films for heater applications. The self-assembled graphene hybrid films with the area of 20 × 20 cm 2 could be transferred onto arbitrary substrates with nonplanar surfaces and simply patterned with the hard mask. After reduction by hydrogen iodide vapor followed by 800 °C thermal treatment, the hybrid films with the transmittance of 76.2% exhibit good heating characteristics and defogging performance, which reach a saturation temperature of up to 127.5 °C when 40 V was applied for 60 s. [ABSTRACT FROM AUTHOR]

SmBaCo 2−x−y Mn x Mg y O 5+δ (x = 0.5, 1, 1.5 and y = 0.05, 0.1) samples are synthesized by sol-gel method. The influence of different substitution of Mn and Mg for Co on crystal structures, thermal expansion coefficient (TEC), electrical conductivities and electrochemical performances have been investigated. The generation of the secondary phase BaMnO 3 is suppressed with Mg 2+ increasing. Demonstrated by temperature-dependent X-ray diffraction from 25 °C to 700 °C, the structure of SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ in high temperature is stable. The TEC of SmBaCo 1.45 Mn 0.5 Mg 0.05 O 5+δ , SmBaCo 0.95 MnMg 0.05 O 5+δ , SmBaCo 0.45 Mn 1.5 Mg 0.05 O 5+δ and SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ are 15.77 × 10 −6 K −1 , 16.20 × 10 −6 K −1 , 12.19 × 10 −6 K −1 and 12.58 × 10 −6 K −1 , respectively, which are much lower than those of cobalt-based layered perovskites and more compatible with the thermal expansion of SDC electrolyte. Although the electrochemical performances of SmBaCo 2−x−y Mn x Mg y O 5+δ (x = 0.5, 1, 1.5 and y = 0.05, 0.1) decrease slightly with Mn increasing, the polarization resistances of the SmBaCo 1.45 Mn 0.5 Mg 0.05 O 5+δ and SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ are 0.17 Ω cm 2 and 0.30 Ω cm 2 at 800 °C, respectively, which can meet the electrochemical performance requirements of cathode materials. Among the samples, the SmBaCo 1.45 Mn 0.5 Mg 0.05 O 5+δ and SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ show better tradeoff properties between TEC and electrochemical performance as cathode materials for IT-SOFCs. [ABSTRACT FROM AUTHOR]

In this study, an acidic polysaccharide (CAs) was extracted and purified from the peels of Citrus aurantifolia by Sephadex G-150. HPGPC showed the molecular weight of CAs was about 7.94 × 10 6 Da. Ion chromatography (IC) analysis showed CAs was mainly composed of rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glu), mannose (Man) and galacturonic acid (GalA), with the molar ratio of 0.67: 7.67: 10.83: 3.83: 4.00: 1.00. 1 H and 13 C NMR spectra of CAs also identified the presence of five kinds of monosaccharides and galacturonic acid. Moreover, the antitumor activity of CAs was evaluated in mice transplanted H22 hepatoma cells. It was shown that CAs dose-dependently suppressed tumor cells growth with few toxic effects on host. Further investigations revealed that CAs increased the levels of tumor infiltrating CD8 + T lymphocytes, blocked tumor cell cycle in S phase, down-regulated anti-apoptotic protein Bcl-xL and Mcl-1 expression, and led to the activation of caspase 3. These results suggested that CAs had capacity of inducing tumor cells apoptosis in vivo , and it supported considering CAs as an adjuvant reagent in hepatocellular carcinoma treatment. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Embryonic stem cells (ESCs) can undergo unlimited self-renewal and maintain pluripotency to differentiate into any cell type of the three germ layers. Extensive studies have shown ESC identity is regulated by transcription factors, epigenetic regulators and multiple signal transduction pathways. However, the kinase regulation of pluripotency is not well understood. Here we show that the serine/threonine kinase PIM2, which is highly expressed in ESCs but not in somatic cells, functions as a crucial stemness regulator in ESCs. Knockout of Pim2 inhibits the self-renewal and differentiation capability of ESCs. Mechanistic studies identified that PIM2 can directly phosphorylate 4E-BP1, leading to release of eIF4E which facilitates the translation of pluripotent genes in ESCs. Our study highlights a novel kinase cascade pathway for ESC identity maintenance. [ABSTRACT FROM AUTHOR]

Avian pathogenic Escherichia coli (APEC), an extraintestinal pathogenic E. coli (ExPEC), constitutes an animal health and a potential zoonotic risk. Most studies focus on the response of a single tissue to APEC infection. Understanding interactions among lymphoid tissues is of importance in controlling APEC infection. Therefore, we studied bone marrow, bursa, and thymus transcriptomes because of these tissues' crucial roles in development of pre-lymphocytes, B cells, and T cells, respectively. Using lesion scores of liver, pericardium, and air sacs, infected birds were classified as either resistant or susceptible. Little difference in gene expression was detected in resistant birds in bone marrow versus bursa or thymus, while there were large differences between tissues in susceptible birds. Phagosome, lysosome and cytokine interactions were strongly enhanced in thymus versus bone marrow in susceptible birds, and T cell receptor (TCR), cell cycle, and p53 signaling were significantly decreased. B cell receptor (BCR) was also significantly suppressed in bursa versus bone marrow in susceptible birds. This research provides novel insights into the complex developmental changes in gene expression occurring across the primary lymphoid organs and, therefore, serves as a foundation to understanding the cellular and molecular basis of host resistance to APEC infection. [ABSTRACT FROM AUTHOR]

The induction of polyploidy to improve agronomically and economically useful characters is a process commonly used in crop plants. Neopolyploids were obtained from the diploid pear cultivar ‘Fertility’ by in vitro colchicine treatment. Different clones of polyploids were rooted to be transferred to the greenhouse and then to the net house, a survey orchard was established. The morphological characteristics and the performance of 3 tetraploid clones, 2 triploid clones, 1 mixploid clone and a diploid control were investigated under greenhouse and field conditions. Results revealed that plants of different neopolyploids showed markedly different phenotypic traits. Compared to the diploid control, three out of four polyploid clones plants had significantly thicker leaves and a shorter petiole length. The significance of the difference in leaf index (ratio of leaf lamina length to leaf lamina width) between diploid and polyploids depended on the individual clone of the neopolyploid plants. In the greenhouse and the field, the triploid clone ‘3 x − 1’ and the tetraploid clones ‘4 x − 1’ and ‘4 x − 2’ had significantly decreased leaf index, and the triploid ‘3 x − 2’ had significantly increased leaf index. However, the tetraploid clone ‘4 x − 4’ and the mixploid clone ‘Mi x − 1” showed phenotypic abnormalities, such as stunted growth and leaf malformation. The ex vivo grafted shoots of the pentaploid ‘5 x − 1’ and ‘5 x − 2’ were very difficult to maintain or had a very short survival period. The grafted plants of triploid ‘3 x − 2’ showed a compact habit. Most neopolyploid plants had significantly shorter internodes and all had reduced plant height compared to the height of their parent diploid plants. [ABSTRACT FROM AUTHOR]

A novel carbon-supported Pt-V-SnO 2 catalyst is prepared by a modified Bönnemann method. Pt/C, PtV/C, and PtSnO 2 /C are used for comparative analysis to study PtVSnO 2 /C in terms of its structure and electrocatalytic activity for the ethanol oxidation reaction (EOR). Characterization of its structural properties by X-ray diffraction (XRD) and transmission electron microscopy (TEM) is described. It is shown that the Pt lattice parameter decreases with the addition of V but increases with the addition of Sn in the PtVSn/C catalyst. TEM analysis reveals that the prepared catalyst particles are in the nanosize range (2-4 nm). EDS confirms the atomic compositions of the synthesized catalysts to be similar to the nominal values. The electrocatalytic activities are characterized by cyclic voltammetry (CV) and amperometric i - t curve measurement ( i - t ) techniques. The incorporation of a small amount of V in the PtSnO 2 /C electrocatalyst leads to higher activity for the ethanol oxidation reaction at room temperature. According to the Arrhenius equation, the apparent activation energy of PtVSnO 2 /C (3:1:3) for EOR is the lowest among the studied catalysts, which may be attributed to a synergistic effect between Sn and V. [ABSTRACT FROM AUTHOR]

Abstract: Thin films of solid electrolyte La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) were deposited by RF magnetron sputtering onto porous La0.7Sr0.3Cr0.5Mn0.5O3−δ (LSCM) anode substrates. The effects of substrate temperature, sputtering power density and sputtering Ar gas pressure on the LSGM thin film density, flatness and morphology were systematically investigated. RF sputtering power density of 7.8Wcm−2, substrate temperature of 300°C and sputtering Ar gas pressure of 5Pa are identified as the best technical parameters. In addition, a three-electrode half cell configuration was selected to investigate the electrochemical performance of the thin film. The LSGM film deposited at optimum conditions exhibited a lower area specific ohmic resistance of 0.68Ωcm−2 at 800°C, showing that the practicability of RF magnetron sputtering method to fabricate LSGM electrolyte thin film on porous LSCM anode substrates. [Copyright &y& Elsevier]

Abstract: The present study investigated Typha angustifolia leaf proteome in response to Cr, Cd and Pb stress. T. angustifolia of 90 (D90) and 130d (D130) old plants were subjected to 1mM Cr, Cd and Pb and samples were collected 30d after treatment. 2-DE coupled with MS (mass spectrometry) was used to analyze and identify Cr, Cd and Pb-responsive proteins. More than 1600 protein spots were reproducibly detected on each gel, wherein 44, 46, 66 and 33, 26, 62 spots in D90 and D130 samples were differentially expressed by Cr, Cd, Pb over the control, respectively. Of these differentially expressed proteins, 3, 1, 8 overlapped in D90 and D130; while 5, 8, 5 with regulation factors above 3 in one of D90 or D130 samples. Total of 22 and 4 up- and down-regulated proteins were identified using MS and data bank analysis. Cr-induced expression of ATP synthase, RuBisCO small subunit and coproporphyrinogen III oxidase; Cd-induced RuBisCO large subunit; Pb up-regulated carbohydrate metabolic pathway enzymes of fructokinase, and improved RuBisCO activase and large subunit, Mg-protoporphyrin IX chelatase. Contrarily, elF4F was inhibited by Cr/Pb, chloroplast FtsZ-like protein and GF14omega impeded by Cd and Pb, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The kinetics and reactivity associated with the CO+OH and CO+HO2 reactions were analyzed based on ab initio molecular orbital theory, with the interest of identifying the difference in their reaction dynamics that leads to the slower rate of the latter. Two hydrogen-bonded pre-reactive complexes, OOH···OC and OOH···CO, were found on the potential energy surface of CO+HO2, having energies that are higher than those of the entrance reactants by 1.2 and 2.9kcalmol−1, respectively. Through intrinsic reaction coordinate analysis, it was further found that these two complexes hinder the forward reaction, HO2 +CO→products, by forcing a reorientation of the reactants. The configurations of the transition state structures in forming the trans/cis intermediates in the title reactions were rationalized by virtual representation of the electrostatic potentials of the reactants from self-consistent field calculations at the CCSD(T)/AUG-cc-pVTZ level, with the different reactivities of the two reactions ascribed to spatial interactions between the local electrostatic potentials of the entrance reactants. The energy gap of the frontier molecular orbitals for the CO+OH entrance channel was found to be ca. 29kcalmol−1 lower than that of the CO+HO2 entrance channel by time-dependent coupled cluster theories, which quantitatively explains the difference in their reactivities. Furthermore, the condensed Fukui functions were calculated using Mulliken atomic charges through natural population analysis to identify the most reactive sites of the entrance reactants, with the results again supporting the slower reaction rate of CO+HO2. [Copyright &y& Elsevier]

Abstract: One of the critical issues in the generation of a protein microarray lies in the choice of immobilization strategies, which ensure proteins are adhered to the glass surface while properly retaining their native biological activities. Herein, we report a bacterium-based, intein-mediated strategy to generate N-terminal cysteine-containing proteins which are then chemoselectively immobilized to a thioester-functionalized glass slide to generate the corresponding protein microarray. We also showed preliminary data of the strategy in a yeast host system. [Copyright &y& Elsevier]

Zr-doped LiNi 0.5 Mn 1.49 Z r0.01 O 4 and pristine LiNi 0.5 Mn 1.5 O 4 with ordered and disordered structures were prepared by a low-temperature solution combustion synthesis method. The phase compositions, structural ordering and micro-morphologies of the products were characterized by X-ray diffraction, energy-dispersive spectroscopy, inductive coupled plasma, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy measurements. The electrochemical performances of the products were investigated by charge/discharge testing, cyclic voltammetry, and electrochemical impedance spectroscopy. The results indicate that the effects of Zr doping on ordered or disordered LiNi 0.5 Mn 1.5 O 4 are different. Ordered LiNi 0.5 Mn 1.49 Z r0.01 O 4 shows much better cycling stability and rate capability than that of ordered LiNi 0.5 Mn 1.5 O 4 . In contrast, the cycling stability of disordered LiNi 0.5 Mn 1.5 O 4 changes little, and the rate capability decreases after Zr doping. After 200 cycles at 1 C, the capacity retentions of ordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 and LiNi 0.5 Mn 1.5 O 4 are 95.0% and 78.0%, respectively, while the capacity retentions of disordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 and LiNi 0.5 Mn 1.5 O 4 are 98.6% and 95.1%, respectively. In particular, the specific capacity of ordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 is as high as 129.4 mA h/g and retains 94.5% after 100 cycles at 10 C, whereas the specific capacity of ordered LiNi 0.5 Mn 1.5 O 4 is only 103.0 mA h/g and retains 84.0% at the same conditions. The excellent electrochemical performance of ordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 could be attributed to its better crystallinity, higher lithium diffusion coefficient ( D Li ), and lower polarization. [ABSTRACT FROM AUTHOR]

The technical advance of plasma enhanced chemical vapor deposition (PECVD) exhibits the potential to grow large-area high-quality graphene films at relatively low growth temperature, which is beneficial to the fabrication of graphene-based electronic devices/sensors and transparent electrode. However, it remains a challenge to overcome the degradation of graphene quality during growth by PECVD, due to the continuous bombardment of plasma ions on the catalyst surface. Herein, the combined techniques of PECVD and the growth of graphene underneath the catalyst layer were proposed. As a result, transfer-free single-layer graphene films with 2.5 inch in diameter on quartz substrate can be obtained with the growth temperature of 700 °C, which is 250 °C lower than that for graphene synthesis using thermal CVD. The graphene films prepared by our method show the ability to form on the rough surfaces with millimeter-scale grooves and have minimal surface contamination, compared to that of conventionally transferred CVD graphene. [ABSTRACT FROM AUTHOR]

Abstract: A meta-analysis was conducted to evaluate the association of ICAM-1 K469E gene polymorphism with diabetic retinopathy susceptibility in Type 2 diabetes mellitus. Seven studies involving 1094 cases and 909 controls were included. Current studies suggest that K469E polymorphism in ICAM-1 gene might not affect individual susceptibility to DR. [Copyright &y& Elsevier]

In this study, gradient and double-layer coatings were prepared by atmospheric plasma spraying (APS) with nano ZrO 2 –8%Y 2 O 3 (n–8YSZ)/AlCoCrFeNi high–entropy powder. The microhardness of the gradient coating changed in a manner consistent with the microstructure, and the average bond strength of the gradient coating was 2.50 times higher than that of the double-layer coating, indicating that the gradient structure of the coating can improve the sharp interface of the coating, and play a significant role in dispersion toughening to improve the bond strength of the coating. After 450 thermal cycles, the double-layer coating exhibited transverse propagation cracks accompanying coating spalling. In contrast, vertical cracks occurred inside the gradient coating, effectively increasing the coating strain tolerance and improving the coating life. Simultaneously, internal oxidation and cracks appeared in the substrate during cycles, the cracks were more obvious, and bridging occurred in the substrate of the double-layer coating, the substrate under the protection of the gradient coating produced microcracks that were discontinuous, indicating that the design of the gradient structure of the coating can effectively release the internal stress and improve the thermal shock resistance of the coating. [ABSTRACT FROM AUTHOR]

The existence of chromium in vanadium slag is generally considered to affect its phase composition, micromorphology, and further vanadium extraction by calcification roasting process. In this work, remelting and crystallization were used to prepare vanadium slag with different Cr 2 O 3 mass fractions. The aforementioned effects were then examined through X-ray diffraction, scanning electron microscope, and leaching experiments. Results showed that Cr 2 O 3 content affects spinel phase in vanadium slag. With the increase in Cr 2 O 3 content, chromium was observed in the (Mn, Fe)(V, Cr) 2 O 4 phase with vanadium in a homogeneous form, while the diffraction peak positions of (Mn, Fe)(V, Cr) 2 O 4 shifted by a large angle from the lattice distortion. Further, the average grain size of spinel gradually decreased because of the increase in the number of crystallization centers, and the distribution of Cr, V, and Ti in the spinel phase were gradually homogenized instead of having obvious stratification. After calcification roasting, vanadium and chromium existed in the form of vanadate and (Fe 0.6 Cr 0.4) 2 O 3 , achieving the complete separation of them after acid leaching. The increase in Cr 2 O 3 content had no significant effect on the leaching behavior of vanadium. Additionally, increasing the roasting temperature and accelerating the heating process contributed to restraining chromium extraction. These results provide a research basis for the resource utilization of vanadium slag and vanadium chromium slag. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the B-doped Si rich oxide (SRO) thin films were deposited and then annealed using rapid thermal annealing (RTA) to form SiO 2 -matrix silicon nanocrystals (Si NCs). The effects of the RTA temperatures on the structural properties, conduction mechanisms and electrical properties of B-doped SRO thin films (BSF) were investigated systematically using Hall measurements, Fourier transform infrared spectroscopy and Raman spectroscopy. Results showed that the crystalline fraction of annealed BSF increased from 41.3% to 62.8%, the conductivity was increased from 4.48×10 −3 S/cm to 0.16 s/cm, the carrier concentration was increased from 8.74×10 17 cm −3 to 4.9×10 18 cm −3 and the carrier mobility was increased from 0.032 cm 2 V −1 s −1 to 0.2 cm 2 V −1 s −1 when the RTA temperatures increased from 1050 °C to 1150 °C. In addition, the fluctuation induced tunneling (FIT) theory was applicable to the conduction mechanisms of SiO 2 -matrix boron-doped Si-NC thin films. [ABSTRACT FROM AUTHOR]

• CircWWP2 was created by back-splicing of exons 2 to 4 of the WWP2 gene. • Overexpression of circWWP2 can promote the LPS induced cellular injury via decreasing cell viability, increasing NO product and pro-inflammatory cytokines. • Thirteen miRNAs were identified to interact with circWWP2 , which potentially target 3,264 genes. • The target genes were enriched in the pathways of lysosomes, IgA-producing intestinal immune networks for IgA production, and Notch signaling pathway. CircRNA, a non-coding RNA, is an ideal biomarker and a suitable potential therapeutic target for various disease due to its high stability, species conservation and cell/tissue specificity. Our previous study has found a circular RNA WWP2 (circWWP2) was significantly decreased in chicken macrophages during bacterial infection. However, the function of circWWP2 in chicken macrophages remains unclear. In this study, it was demonstrated that circWWP2 was a stable circular RNA created by back-splicing of exons 2 to 4 of WWP2 via PCR amplification, Sanger sequencing, RNase R exonuclease digestion, and RT-qPCR. Moreover, bioinformatics analysis showed circWWP2 could interact with 13 miRNAs and target 3,264 genes, which were significantly enriched in lysosomes, IgA-producing intestinal immune networks for IgA production, and Notch signaling pathway. Furthermore, CCK8 and RT-qPCR indicated that overexpression of circWWP2 could promote lipopolysaccharide (LPS)-induced cellular injury by decreasing cell viability and increasing the expression levels of pro-inflammatory cytokines and pro-apoptosis genes, and NO production. CircWWP2 may exert a potential target for the treatment of bacterial infection. Further experiments are necessary to validate the specific mechanism that circWWP2 regulates LPS induced cellular immune responses. [ABSTRACT FROM AUTHOR]

The non-O1/non-O139 Vibrio cholerae caused outbreaks or sporadic cases of gastroenteritis that was rarely seen in good sanitary condition. It was described a case of systemic multiple organ lesions that worsened because of non-O1/non-O139 V. cholerae , suggesting that serogroups have a potential virulence in enhancing pathogenicity with patients with underlying diseases compared with a healthy population. Samples are identified by strain culture, polymerase chain reaction (PCR) virulence identification, and whole genome sequencing. A middle-aged man was diagnosed with cytotoxin-producing and nontoxin V. cholerae non-O1/non-O139 serogroups. Although lacking the CT toxin encoded by ctxAB gene, the pathogenesis of cholera relies on the synergistic action of many other genes, especially virulence genes. This case suggested that the laborers engaging in agricultural production are at potential risk of V. cholerae infection by exposure of open wounds to contaminated water. However, epidemiological investigation should focus on the objective cause of the change of working environment. Furthermore, common diseases can possibly enhance the virulence of non-O1/non-O139 serogroups by attacking the tight junction of small intestinal epithelial cells, further triggering bacteremia, a process that may lead to death within 48–72 hours, which requires great attention. [ABSTRACT FROM AUTHOR]

In order to simplify the template method for the synthesis of cathode materials for lithium ion batteries, a facile template method using plant stalks as bio-templates has been introduced. Based on this method, LiNi 0.5 Mn 1.5 O 4 spinel with a significantly improved electrochemical performance has been synthesized using corn stalk as a template. X-ray diffraction (XRD), Fourier transform infrared pectroscopy (FTIR) and scanning electron microscope (SEM) have been used to investigate the phase composition and micro-morphologies of the products. Charge-discharge measurements in lithium cells, cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) have been used to study the electrochemical performance of the products. The results indicate that the templated product exhibits higher crystallinity than that of non-templated product. Both of the templated product and the non-templated product are combination of the ordered space group P4 3 32 and the disordered Fd-3 m. The specific BET surface area of the templated product is about twice larger than that of the non-templated product. Moreover, the electrochemical performances of the templated product including specific capacity, cycling stability and rate capability are significantly improved as compared with the non-templated product, due to its higher crystallinity, larger Li + diffusion coefficient and lower charge transfer resistance. [ABSTRACT FROM AUTHOR]

Pif is an acid matrix protein that is known to be a key macromolecule in the shell nacre formation of molluscs. However, the investigation into the Pif gene at the whole genome level has seldom been carried out, limiting the systematic understanding of its evolution and function. The Yesso scallop (Patinopecten yessoensis), an ancient bivalve with important economic value and evolutionary status, has suffered severe shell infestation by Polydora that badly damaged shell structures. In this study, a total of eight Pif homologous genes (PyPif1 – 7 and PyBMSP) were identified in the whole genome of the Yesso scallop with diverse gene structures. Two conserved functional domains, VWA and chitin-binding domains, were detected in all PyPif proteins, although with variation in number of copies. Phylogenetic analysis of the Pifs among different molluscan species suggested the molecular evolution of Pif genes was consistent with taxonomic relationships. High sequence divergence of Pif proteins existed among the different species, but a high level of similarity was found in BMSPs, which own four VWA domains. High expression levels of PyBMSP in the central mantles of the healthy and Polydora shell infested Yesso scallops indicated its important role in shell formation. The other PyPifs (PyPif2 , PyPif3, PyPif4, PyPif5, PyPif6) may function when the shell is injured, as significantly increased expression levels of these genes were found in the edge mantles of the infested scallops. In addition, haemocytes may also participate in shell repair by up-regulating the expression of PyPifs. This study provides new insights into the evolution and expression patterns of Pif genes in molluscs, which are valuable for elucidating the mechanism of shell repair and formation. • This is the first genome-wide identification and characterization of Pif homologous genes in mollusc. • A total of eight Pif homologous genes were identified in the whole genome of the Yesso scallop with diverse gene structures. • Expression analysis of PyPifs in healthy and shell infested Yesso scallops implied their important roles in shell formation. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNA) originate from back-splicing events that link a downstream 5'splice site to an upstream 3′ splice site. Circular RNA has been shown to be involved in gene expression, interacting with microRNA and RNA binding proteins to affect transcription, splicing, translation, and other processes. However, little is known about the potential function of chicken circRNAs that trigger the pathogenesis. In a previous study, a circular RNA DNAJB6 (circDNAJB6) was identified as a typical covalently closed circular RNA that is abundant in chicken macrophages upon bacterial infection. It was identified that circDNAJB6 was formed by reverse splicing of exons 2 to 5 of the DNAJB6 gene by PCR amplification, Sanger sequencing, and RNase R exonuclease treatment. Moreover, circDNAJB6 had ability to exacerbate the lipopolysaccharides (LPS) induced cellular injury via reducing cell viability, increasing NO product and pro-inflammatory cytokines. In addition, bioinformatic analysis showed that five miRNAs were identified to interact with circDNAJB6 , potentially targeting 75 genes, which were significantly enriched in the pathways of autophagy-animal and MAPK signaling. This study has provided and broadened a better understanding the function of circDNAJB6 , which may exert potential biomarkers and act as potential targets for the treatment of bacterial infection. • CircDNAJB6 was formed by reverse splicing of exons 2 to 5 of the DNAJB6 gene. • CircDNAJB6 can exacerbate the LPS induced cellular injury via increasing NO product and pro-inflammatory cytokines. • Five miRNAs were identified to interact with circDNAJB6 , which potentially target 75 genes. • The target genes were enriched in the pathways of autophagy-animal and MAPK signaling. [ABSTRACT FROM AUTHOR]

Abstract: A capillary zone electrophoresis (CZE) method modified by β-cyclodextrin (β-CD) and acetonitrile (ACN) was developed for simultaneous determination of seven structurally similar flavonoids in Scutellariae Barbatae Herba (SBH) and its preparations. Molecular selectivity of the analytes by β-CD was in the following order: apigenin, luteolin, quercetin, scutellarin, baicalein, rutin and wogonin, based mainly on the “molecular fit” interaction between some ligands in the C ring of the flavonoid and the cavity of β-CD. Flavonoids with hydroxyl substituent(s) at the C-ring, especially the 4′ monohydroxyl, were highly selected by β-CD although hydrophobicity of the guest molecule is the primary factor affecting the complexation. The function of acetonitrile in this study was to improve the separation of the analytes in the real SBH. The developed method was validated and applied to real samples. The principle of separation based on this CZE condition is also explained. [Copyright &y& Elsevier]

Previously reported light-controlled nitric oxide donors are usually activated by blue or green light. The insufficient ability of short wavelength light to penetrate tissues and its potential phototoxicity to living organisms greatly restricted in vivo applications. This study presents the development of a novel mitochondria-targeted nitric oxide donor, R–NO , capable of controlled nitric oxide and photosensitizer release under white light irradiation in mitochondria. R–NO is capable of generating nitric oxide and R–NH , a novel photosensitizer that can produce O 2 •- upon irradiation with a single light source. In addition, the highly toxic ONOO− can be produced by the rapid reaction of nitric oxide and O 2 •-. Harnessing the synergistic effects of PDT, nitric oxide therapy and highly toxic ONOO−, the proliferation and migration of cancer cells can be significantly inhibited upon light irradiation with R–NO. Futhermore, our MTT experiments demonstrated that simultaneous producing of O 2 •- and nitric oxide in the same region is crucial for efficient cancer cell inhibition. These interesting findings underscore the enhanced synergistic effect achieved by combining PDT and NO therapy in a single molecule for cancer cell treatment. [Display omitted] • A novel mitochondria-targeted nitric oxide donor has been provided. • The controlled nitric oxide and photosensitizer release under white light irradiation has been proved. • The synergistic effects of PDT, nitric oxide therapy and highly toxic ONOO− has been investigated. • The proliferation and migration of cancer cells have been significantly inhibited upon light irradiation with R–NO. [ABSTRACT FROM AUTHOR]

• A novel mitochondrion-targeting turn-on fluorescent probe RThy for detecting •OH. • Its turn on mechanism is based on the cleavage of azo-bond by •OH. • The azo group acts not only as a quenching-group but also as recognizing-group of •OH. • It successfully tracked mitochondrion •OH in live cells and zebrafish. Detection and imaging of hydroxyl radical (•OH) with high sensitivity and selectivity in biological systems is of great importance in evaluating the role of •OH plays in the physiological and pathological processes. Herein, a novel mitochondrion-targeting turn-on fluorescent probe RThy , has been developed to detect •OH in living cells and zebrafish. Probe's turn on mechanism is based on the cleavage of azo-bond by •OH. In RThy sensing system, possessing two groups: a lipophilic cation as a targeting-group, and an azo group acts not only as a quenching-group for tunable light absorption but also as recognizing-group of •OH. In the absence of •OH, almost non-fluorescence emission at 550 nm was observed. However, after reaction with •OH, bright fluorescence emission at 550 nm gradually increased with the continuous addition of •OH, displaying ˜50 folds fluorescence intensity enhancements and a quite low detection limit of 8 nM. The selectivity test showed RThy exhibits excellent selectivity toward •OH among all the ROS/RNS species tested. Furthermore, the probe has been successfully employed for imaging •OH in living cells and zebrafish, thus demonstrating RThy as a useful tool for studying •OH in practical sample application, and providing powerful theoretical basis and technical support for investigation of the interaction •OH with physiological and pathology. [ABSTRACT FROM AUTHOR]

Membrane filtration combined with pre-coagulation has advantages in advanced wastewater treatment. As a model of a microbial polysaccharide, research on the effect of sodium alginate (SA) on alum hydrolysis has been rare; therefore, it is necessary to gain insight into the interface interaction between SA molecules and Al species, and the role SA plays during floc formation. In this study, the interaction mechanism between SA and Al species has been investigated, by evaluating the effect of SA on floc characteristics and membrane fouling during coagulation–ultrafiltration with different Al species coagulants (AlCl 3 and preformed Al 13). Al 2p X-ray photoelectron spectroscopy (XPS) confirmed that the complexation of ligands and Al species strongly affects the reaction pathways for Al hydrolysis and the final nature of the flocs, as Al 13 can be decomposed into octahedral precipitates when SA is added. The presence of SA can affect floc properties, which have important impacts on the characteristics of the cake layer and membrane fouling. Due to the bridging ability of SA, the floc strength increased by about 50% using Al a , which was much better than preformed Al 13 , with a percentage increase of only about 6%. Moreover, the recovery factor of HA-flocs was decreased from 96% to 43% with SA addition of 0.5 mg/L. It was concluded that SA can affect the characteristics of the cake layer and membrane fouling through participating in the formation of primary flocs and altering the Al hydrolysis pathway. Unlabelled Image [ABSTRACT FROM AUTHOR]

High performance sorting of circulating tumor cells (CTCs) from peripheral blood is key to liquid biopsies. Size-based deterministic lateral displacement (DLD) technique is widely used in cell sorting. But conventional microcolumns have poor fluid regulation ability, which limits the sorting performance of DLD. When the size difference between CTCs and leukocytes is small (e.g., less than 3 μm), not only DLD, many size-based separation techniques fail due to low specificity. CTCs have been confirmed to be softer than leukocytes, which could serve as a basis for sorting. In this study, we presented a multistage microfluidic CTCs sorting method, first sorting CTCs using a size-based two-array DLD chip, then purifying CTCs mixed by leukocytes using a stiffness-based cone channel chip, and finally identifying cell types using Raman techniques. The entire CTCs sorting and analysis process was label free, highly pure, high-throughput and efficient. The two-array DLD chip employed a droplet-shaped microcolumn (DMC) developed by optimization design rather than empirical design. Attributed to the excellent fluid regulation capability of DMC, the CTCs sorter system developed by parallelizing four DMC two-array DLD chips was able to process a sample of 2.5 mL per minute with a recovery efficiency of 96.30 ± 2.10% and a purity of 98.25 ± 2.48%. To isolate CTCs mixed dimensionally by leukocytes, a cone channel sorting method and chip were developed based on solid and hydrodynamic coupled analysis. The cone channel chip allowed CTCs to pass through the channel and entrap leukocytes, improving the purity of CTCs mixed by leukocytes by 1.8-fold. • The multistage microfluidic cell sorting method is the only reported whole microfluidic label free sorting analysis method. • The droplet-shaped microcolumn improved the sorting performance of the deterministic lateral displacement technique. • Developed a CTCs sorter system, and the performance of this system surpasses most microfluidic label free technologies. • Developed a cone channel sorting method and chip, improving the purity of CTCs mixed by leukocytes 1.8-fold. [ABSTRACT FROM AUTHOR]

Resazurin (RZ) is a low-toxic redox-sensitive indicator that is weakly fluorescent but becomes strongly fluorescent after reducing to resorufin (RS). The focal point attracting the attention of researchers to this indicator is connected to its excellent sensitivity to a wide range of physical and chemical reaction properties. The sensitive reduction of RZ causing the colour/fluorescence change could be readily triggered by i) biochemical agents or enzymes found in the mitochondria of both the prokaryotic and eukaryotic cells ii) chemical agents like the electrochemical redox species or reductants, single molecule catalytic species, and iii) some physical properties like UV radiation, pH, etc. Interestingly, these redox reaction activators are a segment of most biochemical, electrochemical, photochemical, and microbial reaction processes. Hence, they have been exploited to develop quite several analytical assays for analyzing photo-catalysts, food, drugs, nanoparticles catalyzed reactions, single-molecule detection, and the metabolic activity of a wide range of micro-organisms. • Resazurin sensitive redox reactions find applications in cell viability. • The sensitivity to cytoplasmic enzymes provides swift food testing and drug screening. • The photosensitivity of resazurin affords quick assessment of photo-catalysts. • The staining tendency useful in fluorescent labels-assisted single molecule detection. [ABSTRACT FROM AUTHOR]

Abstract Skin provides the protective barrier for our body and undergoes the continuous regeneration in order to overcome damage from exposure to harmful environments and wounds. Epidermal stem cells (ESCs) play critical roles in skin regeneration. Humanin analogue, S14G-humanin (HNG), a prominent member of a newly discovered family of mitochondrial-derived peptides, has been shown to be a cytoprotective derivative in multiple cell types. In this study, we isolated mouse epidermal stem cells and investigated the cytoprotective effects of HNG on ESCs upon ultraviolet (UV)-B treatment. We show that HNG suppresses UV-B-induced ROS production and increases antioxidant glutathione expression. HNG-pretreated cells exhibit very mild production of cytokines, including TNF-α, IL-1β, and IL-6, upon exposure to UV-B. HNG pretreatment is protective against UV-B-mediated cytotoxicity and promotes ESC survival. Moreover, HNG treatment attenuates the UV-B-induced reduction in mitochondrial membrane potential (MMP) and preserves their identity and stem cell capacity. Mechanistically, HNG treatment ameliorates the UV-B-induced reduction in Wnt/β-catenin pathway proteins, including Wtn3a, Myc, and cyclin D1. Collectively, our data suggest that HNG acts as a pro-survival and anti-oxidative stress agent in ESCs and has the potential to be used in ESC-mediated therapies. [ABSTRACT FROM AUTHOR]

Avian pathogenic E. coli (APEC) has been detected to cause many acute and chronic diseases, resulting in huge economic losses to the poultry industry. Previous experiments have identified the effect of receptor interacting serine/threonine kinase 2 (RIP2) gene in APEC infection. Moreover, increasing evidence indicates that long noncoding RNAs (lncRNAs) play important roles in the anti-bacteria responses. However, little is known about the functions of lncRNAs, especially related to RIP2 , in response to APEC. Therefore, we tried to reveal lncRNAs potentially involved in the immune and inflammatory response against APEC infection, with a particular focus on those possibly correlated with RIP2. A total of 1856 and 1373 differentially expressed (DE) lncRNAs were identified in knockdown of RIP2 cells following APEC infection (shRIP2+APEC) vs. APEC and shRIP2 vs. wild type cells (WT), respectively, which were mainly enriched in lysosome, phagosome, NOD-like receptor signaling pathway, TGF-beta signaling pathway. Significantly, TCONS_00009695 regulated by RIP2 could directly alter the expression of target BIRC3 to modulate cytokines and to participate in immune and inflammatory response against APEC infection. Our findings aid to a better understanding of host responses to APEC infection and provide new directions for understanding the potential association between lncRNAs and APEC pathogenesis. • LncRNAs were involved in host immune response against APEC infection and RIP2 regulation. • 1,856 and 1,373 DE lncRNAs were identified in shRIP2 + APEC vs. APEC and shRIP2 vs. WT, respectively. • Those lncRNAs were mainly enriched in lysosome, phagosome, NOD-like receptor signaling pathway. • LncT9695 regulated by RIP2 can participate in cellular immune response by modulating BIRC3. [ABSTRACT FROM AUTHOR]

Graphene is widely recognized as a promising nanomaterial for the construction of high-performance electrochemical biosensors. However, the lack of strong interfacial forces between graphene and conductive substrates is a bottleneck in the fabrication of highly stable graphene electrodes. In this work, few-layer graphene was directly formed on a high pressure high temperature (HPHT) diamond substrate via sp 3 -to-sp 2 conversion by catalytic thermal treatment and using diamond itself as the carbon source. The hybrid electrode prototype was also highly conductive and had a linear electrochemical response to dopamine in the concentration range of 5 μM – 2 mM, with a low detection limit of 200 nM. After prolonged and repeated exposure to dopamine, electrode fouling was observed which led to sensitivity degradation. Based on the strong interfacial bonding between graphene and HPHT diamond, regeneration of the fouled electrode and full performance recovery would be easily achieved by ultrasonic cleaning. The hybrid electrode is highly robust, and shows potential in its application to the detection of biofouling molecules, food processing and wastewater treatment. [ABSTRACT FROM AUTHOR]

The preparation of scalable graphene films has attracted an enormous attention due to its industrial importance for graphene applications. Here we present a synthesis method of high-quality continuous monolayer graphene films with millimeter-sized domains on ordinary Cu substrates using oxygen-assisted chemical vapor deposition. This method demonstrates a significantly improvement to the resultant graphene such as a largely decreased nucleation density from ∼10 6 to ∼10 1  nuclei/cm 2 , an increased average domain size from ∼0.004 to ∼1.5 mm and a film coverage from 64% to 100%. We attributed the success of this growth to the surface layer formed by bonded oxygen in Cu, which provides a higher priority for catalyzing the nucleation and growth of graphene domains. [ABSTRACT FROM AUTHOR]

To achieve precise control of the signaling events or to achieve unmistakable synthesis of biomolecules, nature has evolved organic reactions involving proteinogenic amino acids with unparalleled site selectivity. For example, dedicated enzymes accurately dictate the site of post-translational modifications in signaling proteins, and ribosomes precisely link the C-terminal carboxylic acid of one unprotected amino acid with the N-terminal amino group of the other amino acid through spatially confined proximity. For many years, chemists have been striving to achieve site selectivity on biomolecules by mimicking nature. Driven by the development of chemoselective protein conjugation reactions, enzymology and protein–protein interactions, the past decade has witnessed a boom in site-selective protein conjugation reactions. (In this review, a site-selective protein conjugation reaction is defined as an organic reaction that targets a single amino acid instead of a kind of amino acids in a protein or a proteome under physiological conditions, for example, a single cysteine residue among all of the cysteines.) In this review, we summarize the recent advancements of bioconjugation reactions that demonstrate this feature of precise site selectivity, focusing on the reactions of the proteinogenic amino acids (excluding those at non-coded or non-proteinogenic amino acids that are introduced to proteins through genetic manipulations). [ABSTRACT FROM AUTHOR]

Alkaline phosphatase (ALP) is a family of enzymes involved in the regulation of important biological processes such as cell differentiation and bone mineralization. Monitoring the activity of ALP in serum can help diagnose a variety of diseases including bone and liver diseases. There has been growing interest in developing new chemical tools for monitoring ALP activity in living systems. Such tools will help further delineate the roles of ALP in biological and pathological processes. Previously reported fluorescent probes has a number of disadvantages that limit their application, such as poor selectivity and short-wavelength excitation. In this work, we report a new two-photon fluorescent probe (TP-Phos) to selectively detect ALP activity. The probe is composed of a two-photon fluorophore, a phosphate recognition moiety, and a self-cleavable adaptor. It offers a number of advantages over previously reported probes, such as fast reaction kinetics, high sensitivity and low cytotoxicity. Experimental results also showed that TP-Phos displayed improved selectivity over DIFMUP, a commonly utilized ALP probe. The selectivity is attributed to the utilization of an ortho-functionalised phenyl phosphate group, which increases the steric hindrance of the probe and the active site of phosphatases. Moreover, the two-photon nature of the probe confers enhanced imaging properties such as increased penetration depth and lower tissue autofluorescence. TP-Phos was successfully used to image the endogenous ALP activity of hippocampus, kidney and liver tissues from rat. [ABSTRACT FROM AUTHOR]

Copper (II) is one of the most of important cofactors for numerous enzymes and has captured broad attention due to its role as a neurotransmitters for physiological and pathological functions. In this article, we present a reaction-based fluorescent sensor for Cu 2+ detection ( NIR-Cu ) with near-infrared excitation and emission, including probe design, structure characterization, optical property test and biological imaging application. NIR-Cu is equipped with a functional group, 2-picolinic ester, which hydrolyzes in the presence of Cu 2+ with high selectivity over completed cations. With the experimental conditions optimized, NIR-Cu ( 5 μM ) exhibits linear response for Cu 2+ range from 0.1 to 5 μM, with a detection limit of 29 nM. NIR-Cu also shows excellent water solubility and are highly responsive, both desirable properties for Cu 2+ detection in water samples. In addition, due to its near-infrared excitation and emission properties, NIR-Cu demonstrates outstanding fluorescent imaging in living cells and tissues. [ABSTRACT FROM AUTHOR]

Thiophenols are widely utilized for producing pesticides, polymers and pharmaceuticals. Studies have shown that prolonged exposure of human to thiolphenol can result in serious health problems such as significant damage of the central nervous system. Herein, we have developed a novel turn-on two-photon fluorescent probe TP-ASH for selective and sensitive detection of thiophenols. We first constructed a new two-photon dye by connecting a coumarin fluorophore and a naphthalene fluorophore through 2,5- disubstituted-1,3,4-oxadiazole ring to afford d -π-A-π- d -structure. Fluorescent studies showed that this new dye possess large two-photon active absorption across-section (250 GM) and high fluorescence quantum yield (0.85). Encouraged by the results, we proceeded to conjugate this novel dye to a thiophenol recognition moiety, 4-dinitrobenzene-ether (DNB). The resulting probe displayed high selectivity towards thiophenols over their similar analogues, aliphatic thiols. The probe also exhibited high sensitivity, with a detection limit of 6.7 nM and a fluorescence enhancement of 163-fold. In addition, we have successfully applied the probe for two-photon imaging studies of thiphenols in living cells and mice tissues. We envision that the probe will add useful tools in detecting thiophenols in environmental samples and biological systems. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H 2 S), one of the biologically important gaseous signal molecules, plays an essential role in diverse normal biochemical functions and pathological processes. Herein, an efficient two-photon in and near-infrared out mitochondria-targeting dye has been designed, synthesized and characterized. It is easily synthesized by the condensation reaction (C˭C) of 4-hydroxybenzaldehyde and 6-(diethylamino)−1,2,3,4-tetrahydroxanthylium (mitochondria-targeting), which possesses large two-photon action absorption cross-section ~160 g and high fluorescence quantum yield ~0.15. Encouraged by the results, we proceeded to conjugate this new dye with a H 2 S recognition moiety (4-dinitrobenzene-ether, DNB), on the basis of the intramolecular charge transfer (ICT) strategy, to construct a novel H 2 S fluorescent probe (TP-NIR-HS), which shows a targeting ability with high sensitivity and selectivity, and low cytotoxicity. This new probe was then applied for two-photon imaging of living cells and tissues and showed high imaging resolution and a deep-tissue imaging depth of ~350 µm, thus demonstrating its practical application in biological systems, and providing a valuable theoretical basis and technical support for the study of physiological and pathological functions of H 2 S. [ABSTRACT FROM AUTHOR]

We report a novel turn-on two-photon fluorescent probe ( TPNF ) for detecting formaldehyde based on aza-Cope rearrangement and intramolecular charge transfer (ICT). The probe, containing a 1,8-naphthalimide dye with a homoallylamino group, has was shown with high selectivity, sensitivity and low cytotoxicity and it was capable of detecting formaldehyde in live cells. Moreover, a time-dependent density functional theory (TD-DFT) calculation was performed to demonstrate the turn on mechanism of the probe via ICT effect. Finally, a zebrafish larvae imaging experiment reveals that TPNF displayed a significant signal change when treated with FA in vivo. These results indicated that TPNF is a promising tool in more biomedical researches. [ABSTRACT FROM AUTHOR]

In contrast to one-photon microscopy, two-photon probe-based fluorescence imaging can provide improved three-dimensional spatial localization and increased imaging depth. Therefore, the development of new functional two-photon fluorescent dye has attracted great attention. Herein, we have adopted the fluorescence resonance energy transfer (FRET) strategy to design a unique type of two-photon ratiometric fluorescent probe platform. Specifically, a two-photon fluorophore (D-π-A-structured naphthalimide derivative) and a rhodamine B fluorophore are directly connected by a flexible piperidine linker. We further used this platform to develop a new type of two-photon ratiometric fluorescent probe, NRLys , for lysosomal pH detection and bioimaging. The experiments demonstrated that the NRLys is a reliable and specific probe for labeling lysosomes in living cells and tissues with two well-resolved emission peaks separated by 60 nm. The probe showed high ratiometric imaging resolution and deep-tissue imaging depth of over 180 μm. Based on the above results, we expect that the new platform may prompt the development of a wide variety of two-photon ratiometric fluorescent probes application in biological systems. [ABSTRACT FROM AUTHOR]

• The structures of small-molecule fluorophores for plasma membrane staining were summarized. • The membrane targeting groups were categorized and summarized. • The mechanisms to achieve the membrane specificty were summarized and discussed. • The bioimaging applications of fluorescent probes were summarized. Plasma membrane (PM), a phospholipid bilayer that separates the interior of cell from the extracellular fluid, is closely involved in various cellular activities. However, monitoring dynamic membrane has always been a challenge due to its dynamic structure and complex constitution. Owing to the distinct advantages of fluorescence imaging technology, diverse small molecular fluorescent probes have been well developed for membrane staining to investigate membrane function and monitor its dynamic activity. Herein, representative small molecular fluorescent probes reported in the last ten years were summarized and categorized into four groups according to their functional membrane-anchoring moieties, namely hydrophobic alkyl chain, ammonium unit, cholesterol, and short peptide sequence. In particular, the underlying mechanisms to achieve membrane-specific fluorescence staining were fully discussed, including membrane targeting group approach, aggregation induced emission (AIE), disassembly light up fluorescence strategy and restricted intramolecular rotation (RIM). Furthermore, membrane-targeting probes for super-resolution imaging of membrane dynamics were presented as an emerging technology. In this review, we showcased recent advances in this research area, and outlined potential challenges and prospects with the goal of driving the generation of innovative fluorescent probes for PM staining. [ABSTRACT FROM AUTHOR]