Plasmon-Mediated Peroxidase-like Activity on an Asymmetric Nanotube Architecture for Rapid Visual Detection of Bacteria

Rapid and sensitive detection of bacteria from a complex real media remains a challenge. Herein, we report a visual bacterial sensing assay with excellent specificity, anti-interference ability, and sensitivity based on a surface plasmon resonance (SPR)-enhanced peroxidase (POD) mimetic. The POD mimetic based on Pt nanoparticles (NPs) asymmetrically decorated on Au/TiO2 magnetic nanotubes (Au/Pt/MTNTs) is designed by combining the intrinsic photocatalytic activity of TiO2 and the limited transport depth of light. It is revealed that the localized surface plasmon resonance (LSPR) effect of the asymmetric nanotubes is more effective in facilitating the generation of hot electrons, which are subsequently transferred to Pt and MTNTs, thus greatly promoting the catalytic performance. Using Staphylococcus aureus (S. aureus) as a model of Gram-positive bacteria, the dependence of the colorimetric reaction on the active sites of the POD mimetic is used for the sensing of target bacteria. Owing to the specific recognition between S. aureus and peptide, the fluorescein isothiocyanate (FITC) labeled peptide probes are captured by S. aureus and removed from the Au/Pt/MTNTs, leading to the recovery of POD-like activity and fluorescence emission of S. aureus. Particularly, benefiting from the Au-SPR effect and the magnetic feature of the Au/Pt/MTNTs, the recovery of catalytic activity induced an improved colorimetric assay with a wider linear response for S. aureus qualification and a detection limit of four cells, as well as satisfactory selectivity and feasibility for application in real samples. The plasmon-enhanced POD activity would provide a simple-yet-effective approach to achieve a colorimetric bioassay with high efficiency and sensitivity. This asymmetric design can also be utilized to engineer nanozymes in colorimetric assays for the specific detection of biotoxins, biomarkers, and cancer cells

Table2_Gonadal transcriptome sequencing reveals sexual dimorphism in expression profiling of sex-related genes in Asian arowana (Scleropages formosus).XLS

Asia arowana (Scleropages formosus) is an ornamental fish with high economic value, while its sex determination mechanism is still poorly understood. By far, no morphological evidence or molecular marker has been developed for effective distinguishment of genders, which poses a critical challenge to our captive breeding efforts. In this study, we sequenced gonadal transcriptomes of adult Asian arowanas and revealed differential expression profiling of sex-related genes. Based on the comparative transcriptomics analysis of testes (n = 3) and ovaries (n = 3), we identified a total of 8,872 differentially expressed genes (DEGs) and 18,490 differentially expressed transposable elements (TEs) between male and female individuals. Interestingly, the expression of TEs usually has been more significantly testis-biased than related coding genes. As expected, several genes related to females (such as foxl2 and cyp19a1a) are significantly transcribed in the ovary, and some genes related to male gonad development (such as dmrt1, gsdf and amh) are highly expressed in the testis. This sexual dimorphism is valuable for ascertaining the differential expression patterns of sex-related genes and enriching the genetic resources of this economically important species. These valuable genetic materials thereby provide instructive references for gender identification and one-to-one breeding practices so as to expand fish numbers for a rapid elevation of economic value.</p

Table1_Gonadal transcriptome sequencing reveals sexual dimorphism in expression profiling of sex-related genes in Asian arowana (Scleropages formosus).DOCX

Asia arowana (Scleropages formosus) is an ornamental fish with high economic value, while its sex determination mechanism is still poorly understood. By far, no morphological evidence or molecular marker has been developed for effective distinguishment of genders, which poses a critical challenge to our captive breeding efforts. In this study, we sequenced gonadal transcriptomes of adult Asian arowanas and revealed differential expression profiling of sex-related genes. Based on the comparative transcriptomics analysis of testes (n = 3) and ovaries (n = 3), we identified a total of 8,872 differentially expressed genes (DEGs) and 18,490 differentially expressed transposable elements (TEs) between male and female individuals. Interestingly, the expression of TEs usually has been more significantly testis-biased than related coding genes. As expected, several genes related to females (such as foxl2 and cyp19a1a) are significantly transcribed in the ovary, and some genes related to male gonad development (such as dmrt1, gsdf and amh) are highly expressed in the testis. This sexual dimorphism is valuable for ascertaining the differential expression patterns of sex-related genes and enriching the genetic resources of this economically important species. These valuable genetic materials thereby provide instructive references for gender identification and one-to-one breeding practices so as to expand fish numbers for a rapid elevation of economic value.</p

Table3_Gonadal transcriptome sequencing reveals sexual dimorphism in expression profiling of sex-related genes in Asian arowana (Scleropages formosus).XLS

Asia arowana (Scleropages formosus) is an ornamental fish with high economic value, while its sex determination mechanism is still poorly understood. By far, no morphological evidence or molecular marker has been developed for effective distinguishment of genders, which poses a critical challenge to our captive breeding efforts. In this study, we sequenced gonadal transcriptomes of adult Asian arowanas and revealed differential expression profiling of sex-related genes. Based on the comparative transcriptomics analysis of testes (n = 3) and ovaries (n = 3), we identified a total of 8,872 differentially expressed genes (DEGs) and 18,490 differentially expressed transposable elements (TEs) between male and female individuals. Interestingly, the expression of TEs usually has been more significantly testis-biased than related coding genes. As expected, several genes related to females (such as foxl2 and cyp19a1a) are significantly transcribed in the ovary, and some genes related to male gonad development (such as dmrt1, gsdf and amh) are highly expressed in the testis. This sexual dimorphism is valuable for ascertaining the differential expression patterns of sex-related genes and enriching the genetic resources of this economically important species. These valuable genetic materials thereby provide instructive references for gender identification and one-to-one breeding practices so as to expand fish numbers for a rapid elevation of economic value.</p

Bioreduction of Gold Ions under Greener Conditions by the Thiol-Modified M13 Bacteriophage and with Hydroxylamine as the Autocatalytic Reducing Agent

Bioreduction of gold ions by the thiol-modified M13 bacteriophage (M13-SH) has been exploited as the potential alternative to conventional methods based on toxic chemicals, due to the gold affinity of the thiol groups, inherent gold reduction, and high specific surface area of the filamentous virus. Such efforts have been hindered by harsh conditions involving strong reducing agents and extreme pH that are harmful to the virus. Herein, a virus-friendly and greener method of bioreduction of AuCl4– at neutral pH based on M13-SH is demonstrated. M13-SH was prepared by coupling the virus with N-succinimidyl S-acetylthioacetate, followed by deacylation in the presence of hydroxylamine·HCl to expose the thiol groups. The key finding is that without time-consuming purification, the mixture after deacylation consisting of M13-SH, residual hydroxylamine, and so forth can directly turn ionic gold species into gold, leading to macroscopic precipitated products with interconnected linear structures consisting of fused gold nanoparticles. Besides working as the virus-friendly reducing agent with a unique autocatalytic style, hydroxylamine diminishes disulfide bonding-induced intervirus bundling of M13-SH so as to maintain its efficient biosorption of ionic gold precursors. This work demonstrates a general and green strategy of bioreduction of gold via combination of the gold-affinity proteins or organisms and the unique autocatalytic reduction of hydroxylamine

Table4_Gonadal transcriptome sequencing reveals sexual dimorphism in expression profiling of sex-related genes in Asian arowana (Scleropages formosus).XLS

Asia arowana (Scleropages formosus) is an ornamental fish with high economic value, while its sex determination mechanism is still poorly understood. By far, no morphological evidence or molecular marker has been developed for effective distinguishment of genders, which poses a critical challenge to our captive breeding efforts. In this study, we sequenced gonadal transcriptomes of adult Asian arowanas and revealed differential expression profiling of sex-related genes. Based on the comparative transcriptomics analysis of testes (n = 3) and ovaries (n = 3), we identified a total of 8,872 differentially expressed genes (DEGs) and 18,490 differentially expressed transposable elements (TEs) between male and female individuals. Interestingly, the expression of TEs usually has been more significantly testis-biased than related coding genes. As expected, several genes related to females (such as foxl2 and cyp19a1a) are significantly transcribed in the ovary, and some genes related to male gonad development (such as dmrt1, gsdf and amh) are highly expressed in the testis. This sexual dimorphism is valuable for ascertaining the differential expression patterns of sex-related genes and enriching the genetic resources of this economically important species. These valuable genetic materials thereby provide instructive references for gender identification and one-to-one breeding practices so as to expand fish numbers for a rapid elevation of economic value.</p

In Situ Fabrication of the Al₂O₃@NiMo Core–Shell Catalyst from LDH for Low-Pressure Hydrodeoxygenation of Fatty Acid Methyl Ester

The hydrothermal stability of supported metal catalysts is one of the greatest challenges in the development of biomass conversion to chemicals and fuels. Herein, a hydrotalcite-based core–shell catalyst (Al2O3@NiMo-LDO) was synthesized by urea precipitation and ion-exchange methods, which could selectively convert bio-oil model compounds to liquid alkanes with high activity and selectivity and excellent hydrothermal stability at low pressure. In the hydrogenation of methyl palmitate, the catalyst afforded 81% conversion and 99% selectivity of n-pentadecane and n-hexadecane under low pressure, with excellent hydrothermal stability. The excellent catalytic performance of Al2O3@NiMo-LDO was attributed to the strong hydrogen activation ability, improvement of the utilization of active components under low pressure, and the increase in the number of active Mo5+ species. The superior hydrothermal stability was attributed to the core–shell structure, which avoided the influence of the specific surface area of Al2O3 that is reduced by the hydration reaction between Al2O3 and H2O at high temperature

Boosting the Local Temperature of Hybrid Prussian Blue/NiO Nanotubes by Solar Light: Effect on Energy Storage

Energy storage devices based on pseudocapacitive materials usually suffer from poor performance at lower temperatures. To address this challenge, in this study, we integrate a Prussian blue analog (PBA) shell on a pseudocapacitive material to achieve a remarkably improved capacitive performance by a solar light-induced heating effect. The capacitor material is prepared by growing a layer of nickel hexacyanoferrate nanocrystals on NiO nanotubes (NTs) via a simple anion-displacement reaction. The electrodes based on optimized PBA/NiO NTs not only exhibit an enhanced capacitance in a natural Li2SO4 aqueous electrolyte but also show a remarkable overall photo-to-thermal conversion efficiency. Most importantly, the local surface temperature can rapidly increase from −4.0 °C to 45.6 °C by solar-light irradiation for only 30 min. Benefitting from the highly increased local temperature, the cation storage ability is highly improved, which shows 377.8% enhancement of specific capacitance at a coulombic efficiency higher than 100%. An asymmetric supercapacitor cell assembled using PBA/NiO NTs and active carbon exhibits distinct thermally enhanced capacitance, mechanical flexibility, and outstanding cycling performance of 15,000 cycles without any capacity decay, indicating the great potential in real application for antidecay of energy storage devices in cold weather. This design paves new pathways to utilize solar light to achieve a suitable working temperature for pseudocapacitors in a low temperature environment (down to approximately −4 °C), thus possessing great application potentials in the field of advanced energy storage devices

Table5_Gonadal transcriptome sequencing reveals sexual dimorphism in expression profiling of sex-related genes in Asian arowana (Scleropages formosus).XLS

Asia arowana (Scleropages formosus) is an ornamental fish with high economic value, while its sex determination mechanism is still poorly understood. By far, no morphological evidence or molecular marker has been developed for effective distinguishment of genders, which poses a critical challenge to our captive breeding efforts. In this study, we sequenced gonadal transcriptomes of adult Asian arowanas and revealed differential expression profiling of sex-related genes. Based on the comparative transcriptomics analysis of testes (n = 3) and ovaries (n = 3), we identified a total of 8,872 differentially expressed genes (DEGs) and 18,490 differentially expressed transposable elements (TEs) between male and female individuals. Interestingly, the expression of TEs usually has been more significantly testis-biased than related coding genes. As expected, several genes related to females (such as foxl2 and cyp19a1a) are significantly transcribed in the ovary, and some genes related to male gonad development (such as dmrt1, gsdf and amh) are highly expressed in the testis. This sexual dimorphism is valuable for ascertaining the differential expression patterns of sex-related genes and enriching the genetic resources of this economically important species. These valuable genetic materials thereby provide instructive references for gender identification and one-to-one breeding practices so as to expand fish numbers for a rapid elevation of economic value.</p

The Fractal Network Structure of Silk Fibroin Molecules and Its Effect on Spinning of Silkworm Silk

Animal silk is usually considered to exist as a solid fiber with a highly ordered structure, formed by the hierarchical assembly starting from a single silk fibroin (SF) chain. However, this study showed that silk protein molecules existed in the form of a fractal network structure in aqueous solution, rather than as a single chain. This type of network was relatively rigid with low fractal dimension. Finite element analysis revealed that this network structure significantly helped in the stable storage of SF prior to the spinning process and in the rapid formation of a β-sheeted nanocrystalline and nematic texture during spinning. Further, the strong but brittle mechanical properties of Bombyx mori silk could also be well-explained through the fractal network model of silk fibroin. The strength was mainly derived from the dual network structure, consisting of nodes and β-sheet cross-links, whereas the brittleness could be attributed to the rigidity of the SF chains between these nodes and cross-links. In summary, this study presents insights from network topology for understanding the spinning process of natural silk and the structure–property relationship in silk materials