A ratiometric fluorescence probe for bisulfite detection in live cells and meat samples.

The development of reliable probe technology for the detection of bisulfite (HSO3-) in situ in food and biological samples is contributing significantly to food quality and safety assurance as well as community health. In this work, a responsive probe, EHDI, is developed for ratiometric fluorescence detection of HSO3- in aqueous solution, meat samples, and living cells. The probe is designed based on the HSO3- triggered 1,4-addition of electron deficit C = C bond of EHDI. As a result of this specific 1,4-addition, the π-conjugation system was destructed, resulting in blue shifts of the emission from 687 to 440 nm and absorption from 577 to 355 nm. The probe has good water solubility, high sensitivity and selectivity, allowing it to be used for imaging of HSO3- internalization and production endogenously. The capability of probe EHDI for HSO3- was then validated by traditional HPLC technology, enabling accurately detect HSO3- in beef samples. The successful development of this probe thus offers a new tool for investigating HSO3- in situ in food and biological conditions.

Recent Advances in Detection of Hydroxyl Radical by Responsive Fluorescence Nanoprobes.

Hydroxyl radical (•OH), a highly reactive oxygen species (ROS), is assumed as one of the most aggressive free radicals. This radical has a detrimental impact on cells as it can react with different biological substrates leading to pathophysiological disorders, including inflammation, mitochondrion dysfunction, and cancer. Quantification of this free radical in-situ plays critical roles in early diagnosis and treatment monitoring of various disorders, like macrophage polarization and tumor cell development. Luminescence analysis using responsive probes has been an emerging and reliable technique for in-situ detection of various cellular ROS, and some recently developed •OH responsive nanoprobes have confirmed the association with cancer development. This paper aims to summarize the recent advances in the characterization of •OH in living organisms using responsive nanoprobes, covering the production, the sources of •OH, and biological function, especially in the development of related diseases followed by the discussion of luminescence nanoprobes for •OH detection.

Cooperation between autotrophic and heterotrophic denitrifiers under low C/N ratios revealed by individual-based modelling.

Denitrifying biofilms, in which autotrophic denitrifiers (AD) and heterotrophic denitrifiers (HD) coexist, play a crucial role in removing nitrate from water or wastewater. However, it is difficult to elucidate the interactions between HD and AD through sequencing-based experimental methods. Here, we developed an individual-based model to describe the interspecies dynamics and priority effects between sulfur-based AD (Thiobacillus denitrificans) and HD (Thauera phenylcarboxya) under different C/N ratios. In test I (coexistence simulation), AD and HD were initially inoculated at a ratio of 1:1. The simulation results showed excellent denitrification performance and a coaggregation pattern of denitrifiers, indicating that cooperation was the predominant interaction at a C/N ratio of 0.25 to 1.5. In test II (invasion simulation), in which only one type of denitrifier was initially inoculated and the other was added at the invasion time, denitrifiers exhibited a stratification pattern in biofilms. When HD invaded AD, the final HD abundance decreased with increasing invasion time, indicating an enhanced priority effect. When AD invaded HD, insufficient organic carbon sources weakened the priority effect by limiting the growth of HD populations. This study reveals the interaction between autotrophic and heterotrophic denitrifiers, providing guidance for optimizing wastewater treatment process.

Advances and Perspectives of Responsive Probes for Measuring γ-Glutamyl Transpeptidase.

Gamma-glutamyltransferase (GGT) is a plasma-membrane-bound enzyme that is involved in the γ-glutamyl cycle, like metabolism of glutathione (GSH). This enzyme plays an important role in protecting cells from oxidative stress, thus being tested as a key biomarker for several medical conditions, such as liver injury, carcinogenesis, and tumor progression. For measuring GGT activity, a number of bioanalytical methods have emerged, such as chromatography, colorimetric, electrochemical, and luminescence analyses. Among these approaches, probes that can specifically respond to GGT are contributing significantly to measuring its activity in vitro and in vivo. This review thus aims to highlight the recent advances in the development of responsive probes for GGT measurement and their practical applications. Responsive probes for fluorescence analysis, including "off-on", near-infrared (NIR), two-photon, and ratiometric fluorescence response probes, are initially summarized, followed by discussing the advances in the development of other probes, such as bioluminescence, chemiluminescence, photoacoustic, Raman, magnetic resonance imaging (MRI), and positron emission tomography (PET). The practical applications of the responsive probes in cancer diagnosis and treatment monitoring and GGT inhibitor screening are then highlighted. Based on this information, the advantages, challenges, and prospects of responsive probe technology for GGT measurement are analyzed.

Organocatalyzed Photo-Controlled Synthesis of Ultrahigh-Molecular-Weight Fluorinated Alternating Copolymers.

Ultrahigh-molecular-weight (UHMW) polymers with tailored structures are highly desirable for the outstanding properties. In this work, we developed a novel photoorganocatalyzed controlled radical alternating copolymerizations of fluoroalkyl maleimide and diverse vinyl comonomers, enabling efficient preparation of fluorinated copolymers of predetermined UHMWs and well-defined structures at high conversions. Versatility of this method was demonstrated by expanding to controlled terpolymerization, which allows facial access toward fluorinated terpolymers of UHMWs and functional pendants. The obtained copolymers exhibited attractive physical properties and furnished thermoplastic, anticorrosive and (super)hydrophobic attributes as coatings on different substrates. Molecular simulations provided insights into the coating morphology, which unveiled a fluorous protective layer on the top surface with polar groups attached to the bottom substrate, resulting in good adhesion and hydrophobicity, simultaneously. This synthetic method and customized copolymers shed light on the design of high-performance coatings by macromolecular engineering.

Fluoropolymer Nanoparticles Synthesized via Reversible-Deactivation Radical Polymerizations and Their Applications.

Fluorinated polymeric nanoparticles (FPNPs) combine unique properties of fluorocarbon and polymeric nanoparticles, which has stimulated massive interest for decades. However, fluoropolymers are not readily available from nature, resulting in synthetic developments to obtain FPNPs via free radical polymerizations. Recently, while increasing cutting-edge directions demand tailored FPNPs, such materials have been difficult to access via conventional approaches. Reversible-deactivation radical polymerizations (RDRPs) are powerful methods to afford well-defined polymers. Researchers have applied RDRPs to the fabrication of FPNPs, enabling the construction of particles with improved complexity in terms of structure, composition, morphology, and functionality. Related examples can be classified into three categories. First, well-defined fluoropolymers synthesized via RDRPs have been utilized as precursors to form FPNPs through self-folding and solution self-assembly. Second, thermally and photoinitiated RDRPs have been explored to realize in situ preparations of FPNPs with varied morphologies via polymerization-induced self-assembly and cross-linking copolymerization. Third, grafting from inorganic nanoparticles has been investigated based on RDRPs. Importantly, those advancements have promoted studies toward promising applications, including magnetic resonance imaging, biomedical delivery, energy storage, adsorption of perfluorinated alkyl substances, photosensitizers, and so on. This Review should present useful knowledge to researchers in polymer science and nanomaterials and inspire innovative ideas for the synthesis and applications of FPNPs.

Red-emitting fluorescent probe for hydrogen sulfide detection and its applications in food freshness determination and in vivo bioimaging.

We report the development of a red-emitting fluorescence probe (XDS) for hydrogen sulfide (H2S) detection in biosystems, real-world food samples, and application of this probe for monitoring of H2S production during food spoilage. The XDS probe is developed by coupling of coumarin derivative to rhodanic-CN through a H2S responsive CC bond. Remarkable fluorescence quenching of XDS is observed as a result of the response to H2S. Semi-quantitative detection of H2S in three real-world water and two beer samples and monitoring of H2S production during food spoilage in real-time by "naked-eye" and smartphone colorimetric analysis are then achieved using XDS as the probe. Moreover, XDS is low toxicity, allowing it being used for visualizing endogenous and exogenous H2S in vivo in a mouse model. It is expected that the successful development of XDS could provide an effective tool for investigating the roles of H2S in biomedical system and for future food safety evaluation.

Development of europium(III) complex functionalized silica nanoprobe for luminescence detection of tetracycline.

Increasing awareness of the health and environment impacts of the antibiotics misuse or overuse, such as tetracycline (TC) in treatment or prevention of infections and diseases, has driven the development of robust methods for their detection in biological, environmental and food systems. In this work, we report the development of a new europium(III) complex functionalized silica nanoprobe (SiNPs-Eu3+) for highly sensitive and selective detection of TC residue in aqueous solution and food samples (milk and meat). The nanoprobe is developed by immobilization of Eu3+ ion onto the surface of silica nanoparticles (SiNPs) as the emitter and TC recognition unit. The ß-diketone configuration of TC can further coordinate with Eu3+ steadily on the surface of nanoprobe, facilitating the absorption of light excitation for Eu3+ emitter activation and luminescence "off-on" response. The dose-dependent luminescence enhancement of SiNPs-Eu3+ nanoprobe exhibits good linearities, allowing the quantitative detection of TC. The SiNPs-Eu3+ nanoprobe shows high sensitivity and selectivity for TC detection in buffer solution. Time resolved luminescence analysis enables the elimination of autofluorescence and light scattering for highly sensitive detection of TC in milk and pork mince with high accuracy and precision. The successful development of SiNPs-Eu3+ nanoprobe is anticipated to provide a rapid, economic, and robust approach for TC detection in real world samples.

Organocatalyzed Controlled Radical Copolymerization toward Hybrid Functional Fluoropolymers Driven by Light.

Photo-controlled polymerizations are attractive to tailor macromolecules of complex compositions with spatiotemporal regulation. In this work, with a convenient synthesis for trifluorovinyl boronic ester (TFVB), we report a light-driven organocatalyzed copolymerization of vinyl monomers and TFVB for the first time, which enabled the controlled synthesis of a variety of hybrid fluorine/boron polymers with low dispersities and good chain-end fidelity. The good behaviors of "ON/OFF" switch, chain-extension polymerizations and post-modifications further highlight the versatility and reliability of this copolymerization. Furthermore, we demonstrate that the combination of fluorine and boron could furnish copolymer electrolytes of high lithium-ion transference number (up to 0.83), bringing new opportunities of engineering high-performance materials for energy storage purposes.

Mainstream partial Anammox for improving nitrogen removal from municipal wastewater after organic recovery via magnetic separation.

Total nitrogen (TN) removal from municipal wastewater after organic recovery is challenging because of the low ratio of chemical oxygen demand (COD) to TN. Anaerobic ammonium oxidation (Anammox) is promising because it has no organic requirement, but its performance in treating effluents following COD captured remains unclear. This study used mainstream partial Anammox to remove nitrogen from effluent following magnetic separation within a continuous-flow anoxic-oxic reactor. Compared with traditional nitrification and denitrification, partial Anammox increased TN removal efficiency by 15.0% and contributed 23.6% of TN removal. Quantitative polymerase chain reaction revealed that the copy number of the Anammox gene (hzsB) increased substantially, while those of the nitrite oxidation (nxrA) and denitrification (narG and nirS) genes decreased. High-throughput sequencing identified Candidatus Brocadia as the dominant genus of anaerobic ammonium-oxidizing bacteria. These findings demonstrate the effectiveness of mainstream partial Anammox for treating COD-captured effluents and its potential in municipal wastewater treatment.

Determination and Imaging of Small Biomolecules and Ions Using Ruthenium(II) Complex-Based Chemosensors.

Luminescence chemosensors are one of the most useful tools for the determination and imaging of small biomolecules and ions in situ in real time. Based on the unique photo-physical/-chemical properties of ruthenium(II) (Ru(II)) complexes, the development of Ru(II) complex-based chemosensors has attracted increasing attention in recent years, and thus many Ru(II) complexes have been designed and synthesized for the detection of ions and small biomolecules in biological and environmental samples. In this work, we summarize the research advances in the development of Ru(II) complex-based chemosensors for the determination of ions and small biomolecules, including anions, metal ions, reactive biomolecules and amino acids, with a particular focus on binding/reaction-based chemosensors for the investigation of intracellular analytes' evolution through luminescence analysis and imaging. The advances, challenges and future research directions in the development of Ru(II) complex-based chemosensors are also discussed.

Quinoline-based fluorescent probe for the detection and monitoring of hypochlorous acid in a rheumatoid arthritis model.

The development of effective bioanalytical methods for the visualization of hypochlorous acid (HOCl) in situ in rheumatoid arthritis (RA) directly contributes to better understanding the roles of HOCl in this disease. In this work, a new quinoline-based fluorescence probe (HQ) has been developed for the detection and visualization of a HOCl-mediated inflammatory response in a RA model. HQ possesses a donor-π-acceptor (D-π-A) structure that was designed by conjugating p-hydroxybenzaldehyde (electron donor) and 1-ethyl-4-methylquinolinium iodide (electron acceptor) through a C[double bond, length as m-dash]C double bond. In the presence of HOCl, oxidation of phenol to benzoquinone led to the red-shift (93 nm) of the adsorption and intense quenching of the fluorescence emission. The proposed response reaction mechanism was verified by high performance liquid chromatography (HPLC) and high-resolution mass spectroscopy (HRMS) titration analysis. The remarkable color changes of the HQ solution from pale yellow to pink enabled the application of HQ-stained chromatography plates for the "naked-eye" detection of HOCl in real-world water samples. HQ featured high selectivity and sensitivity (6.5 nM), fast response time (<25 s) to HOCl, reliability at different pH (3.0 to 11.5) and low cytotoxicity. HQ's application in biological systems was then demonstrated by the monitoring of HOCl-mediated treatment response to RA. This work thus provided a new tool for the detection and imaging of HOCl in inflammatory disorders.

Effect of Astragalus polysaccharide in treatment of diabetes mellitus: a narrative review.

Diabetes mellitus is a chronic endocrine/metabolism disease characterized by hyperglycemia arising from defects in insulin action, insulin secretion, or both. Diabetes mellitus is often complicated by visceral lesions, which can lead to serious complications and death. A variety of new agents are in development for the treatment of the disease. Astragalus polysaccharides are monomer components extracted from the Traditional Chinese Medicine, Huangqi (Radix Astragali Mongolici), which have been studied widely for treating diabetes mellitus with promising effects in recent years. This paper reviews recent advances in experimental studies on the effects of Astragalus polysaccharides in treating diabetes mellitus. The effects of Astragalus polysaccharides on the etiology and complication of diabetes mellitus including insulin resistance and secretion, diabetic neuropathy, diabetic retinopathy, diabetic cardiomyopathy, diabetic foot, and infection complicated by diabetes mellitus are discussed.

Bio-inspired robust non-iridescent structural color with self-adhesive amorphous colloidal particle arrays.

Here we propose a new method for constructing highly color fast non-iridescent structural color materials by assembling self-adhesive poly-dopamine coated SiO2 nanoparticles (PDA@SiO2) for amorphous colloidal arrays through a "spraying" process. Simply by alkaline vapor treatment, the adhesive forces and fastness of the amorphous colloidal arrays were significantly improved. This was demonstrated by lap shear tests of tape tearing and cohesive failure as well as a series of fastness tests like sandpaper abrasion, finger wiping and ultrasonic cleaning. Besides, the strengthening fastness reaction could occur on different substrates, including glass, metals, polymers and paper, regardless of their chemical and physical properties. Moreover, the structural color of the PDA@SiO2 arrays was bright due to the broadband absorption of PDA, and was tunable according to the size, PDA content and arrangement of the PDA@SiO2 arrays.

The complete mitochondrial genome of Himalayan Snowcock (Tetraogallus himalayensis).

We reported here the first complete sequences of mitogenome of Tetraogallus himalayensis obtained by next generation sequencing methods. The assembled mitogenome is a 16 692 bp circle, comprising of 13 protein-coding genes, two rRNA genes (12S rRNA and 16S rRNA), 22 tRNA genes, and one control region. The resultant phylogenetic tree supported T. himalayensis and T. tibeanus are sister taxon, and Tetraogallus with Alectoris and coturnix formed a monophyletic group.