Etched stainless steel wire modified with conjugated microporous polymers-F6 for jacket-free stir bar sorptive extraction of benzoylureas in juice sample.

Benzoylurea (BU) insecticides have been widely used for pest control as third-generation insecticides. Considering that their residues in food may cause adverse effects on human health, the upper limits of BUs remaining in food have been set by the administration. Therefore, it is essential to develop a sensitive and efficient analytical method to determine the residues of BUs in food. Stir bar sorptive extraction (SBSE) is a novel sample preparation technique, and stainless steel wire (SSW) is an ideal substrate for an SBSE device. In this work, a novel SBSE device of SSW jacket-free stir bar with a dumbbell shape was designed and prepared. The conjugated microporous polymer CMP-F6, which possesses a porous structure, high hydrophobicity and rich fluorine-containing functional groups, was immobilized on the surface of SSW by the method of polyacrylonitrile glue adhesion. Compared with previous studies, which used SSW as a substrate, the method of etching partial SSW with hydrochloric acid, on the one hand, made the surface of SSW rough and easy to modify the extraction coating, and on the other hand, converted itself into a dumbbell-shaped structure, which is conducive to improving the extraction efficiency and stability of the SBSE device. The method of SBSE-HPLC-UV was established for determining five BUs. Owing to the hydrophobic interaction and F-F interaction between CMP-F6 and analytes, this method showed good extraction efficiency and had good linearity (R2 ≥ 0.9945) and high sensitivity (LODs in the range of 0.1-0.2 ng mL-1). It was used for the analysis of benzoylurea in an apple juice sample, and the recoveries were 74.3-117.9%.

Binding properties of chemosensory protein 4 in Riptortus pedestris to aggregation pheromones.

In insects, chemosensory proteins (CSPs) play an important role in the perception of the external environment and have been widely used for protein-binding characterization. Riptortus pedestris has received increased attention as a potential cause of soybean staygreen syndrome in recent years. In this study, we found that RpedCSP4 expression in the antennae of adult R. pedestris increased with age, with no significant difference in expression level observed between males and females, as determined through quantitative real-time polymerase chain reaction (qRT-PCR). Subsequently, we investigated the ability of RpedCSP4 to bind various ligands (five aggregated pheromone components and 13 soybean volatiles) using a prokaryotic expression system and fluorescence competitive binding assays. We found that RpedCSP4 binds to three aggregated pheromone components of R. pedestris, namely, ((E)-2-hexenyl (Z)-3-hexenoate (E2Z3), (E)-2-hexenyl (E)-2-hexenoate (E2E2), and (E)-2-hexenyl hexenoate (E2HH)), and that its binding capacities are most stable under acidic condition. Finally, the structure and protein-ligand interactions of RpedCSP4 were further analyzed via homology modeling, molecular docking, and targeted mutagenesis experiments. The L29A mutant exhibited a loss of binding ability to these three aggregated pheromone components. Our results show that the olfactory function of RpedCSP4 provides new insights into the binding mechanism of RpedCSPs to aggregation pheromones and contributes to discover new target candidates that will provide a theoretical basis for future population control of R. pedestris.

The HMGB1-RAGE axis in nucleus accumbens facilitates cocaine-induced conditioned place preference via modulating microglial activation.

INTRODUCTION: Repeated exposure to cocaine induces microglial activation. Cocaine exposure also induces a release of high mobility group box-1 (HMGB1) from neurons into the extracellular space in the nucleus accumbens (NAc). HMGB1 is an important late inflammatory mediator of microglial activation. However, whether the secretion of HMGB1 acts on microglia or contributes to cocaine addiction is largely unknown. METHODS: Rats were trained by intraperitoneal cocaine administration and cocaine-induced conditioned place preference (CPP). Expression of HMGB1 was regulated by viral vectors. Activation of microglia was inhibited by minocycline. Interaction of HMGB1 and the receptor for advanced glycation end products (RAGE) was disrupted by peptide. RESULTS: Cocaine injection facilitated HMGB1 signaling, together with the delayed activation of microglia concurrently in the NAc. Furthermore, the inhibition of HMGB1 or microglia activation attenuated cocaine-induced CPP. Box A, a specific antagonist to interrupt the interaction of HMGB1 and RAGE, abolished the expression of cocaine reward memory. Meanwhile, the inhibition of HMGB1-RAGE interaction suppressed cocaine-induced microglial activation, as well as the consolidation of cocaine-induced memory. CONCLUSION: All above results suggest that the neural HMGB1 induces activation of microglia through RAGE, which contributes to the consolidation of cocaine reward memory. These findings offer HMGB1-RAGE axis as a new target for the treatment of drug addiction.

Correction: Orexin-A Promotes Cell Migration in Cultured Rat Astrocytes via Ca2+-Dependent PKCα and ERK1/2 Signals.

[This corrects the article DOI: 10.1371/journal.pone.0095259.].

First principles insights into the interaction mechanism of iron doped thermally activated kaolinite with Cd and Pb pollutants in organic solid waste incineration flue gas.

Incineration of organic solid wastes is accompanied by the heavy metal emission through flue gas. As an inexpensive and efficient heavy metal adsorbent, the improvement of kaolinite adsorption performance for heavy metals has drawn widespread interests. In this work, the interaction mechanisms between various kaolinite surfaces and Cd/Pb species are explored through first principles calculations. The results show that the combination of Fe doping and dehydroxylation enhances the activity of kaolinite surfaces, analysis of adsorption configurations reveal that both Cd and Pb species are immobilized through chemisorption on the -H + Fe surface. At the microscopic level, further electronic structure analysis shows that the composite modified kaolinite surface has more electron transfer and more pronounced orbital hybridization and overlap compared to the original kaolinite surface, demonstrating that the modification means of dehydroxylation and Fe doping indeed enhanced the activity of the kaolinite surface, especially the activity of the O atoms in the vicinity of the Fe atom and that the O atoms are more efficiently bonded as ionic connecting Cd/Pb species for the purpose of trapping Cd/Pb species. This study points out the research direction and provides basic theoretical support for the development of new kaolinite adsorbents in the future.

Binding properties of chemosensory protein 12 in Riptortus pedestris to aggregation pheromone (E)-2-hexenyl (Z)-3-hexenoate.

Riptortus pedestris (bean bug), a common soybean pest, has a highly developed olfactory system to find hosts for feeding and oviposition. Chemosensory proteins (CSPs) have been identified in many insect species; however, their functions in R. pedestris remain unknown. In this study, quantitative real time-polymerase chain reaction (qRT-PCR) revealed that the expression of RpedCSP12 in the adult antennae of R. pedestris increased with age. Moreover, a significant difference in the expression levels of RpedCSP12 was observed between male and female antennae at one and three days of age. We also investigated the binding ability of RpedCSP12 to different ligands using a prokaryotic expression system and fluorescence competitive binding assays. We found that RpedCSP12 only bound to one aggregation pheromone, (E)-2-hexenyl (Z)-3-hexenoate, and its binding decreased with increasing pH. Furthermore, homology modelling, molecular docking, and site-directed mutagenesis revealed that the Y27A, L74A, and L85A mutants lost their binding ability to (E)-2-hexenyl (Z)-3-hexenoate. Our findings highlight the olfactory roles of RpedCSP12, providing insights into the mechanism by which RpedCSPs bind to aggregation pheromones. Therefore, our study can be used as a theoretical basis for the population control of R. pedestris in the future.

Cell type-specific NRBF2 orchestrates autophagic flux and adult hippocampal neurogenesis in chronic stress-induced depression.

Dysfunctional autophagy and impairment of adult hippocampal neurogenesis (AHN) each contribute to the pathogenesis of major depressive disorder (MDD). However, whether dysfunctional autophagy is linked to aberrant AHN underlying MDD remains unclear. Here we demonstrate that the expression of nuclear receptor binding factor 2 (NRBF2), a component of autophagy-associated PIK3C3/VPS34-containing phosphatidylinositol 3-kinase complex, is attenuated in the dentate gyrus (DG) under chronic stress. NRBF2 deficiency inhibits the activity of the VPS34 complex and impairs autophagic flux in adult neural stem cells (aNSCs). Moreover, loss of NRBF2 disrupts the neurogenesis-related protein network and causes exhaustion of aNSC pool, leading to the depression-like phenotype. Strikingly, overexpressing NRBF2 in aNSCs of the DG is sufficient to rescue impaired AHN and depression-like phenotype of mice. Our findings reveal a significant role of NRBF2-dependent autophagy in preventing chronic stress-induced AHN impairment and suggest the therapeutic potential of targeting NRBF2 in MDD treatment.

Albumin-Based Cyanine Crizotinib Conjugate Nanoparticles for NIR-II Imaging-Guided Synergistic Chemophototherapy.

Colorectal cancer (CRC) is presently the third deadliest cancer in the world. This malignant cancer usually precedes the progression of precancerous lesions, and it is challenging to distinguish its nuanced morphological changes. Molecular-based near-infrared-II (NIR-II) fluorescence imaging can effectively recognize lesion targets to improve image contrast and increase early tumor detection compared with traditional wide-light screening endoscopy. c-Met has been determined to be overexpressed in advanced stages of CRC and is considered to be a potent tumor biomarker. Herein, based on the well-targeted inhibitory effect of Crizotinib on c-Met positive tumor cells, the dye IR808 was covalently combined with the drug molecule Crizotinib, resulting in the synthesis of a NIR fluorescent probe Crizotinib-IR808 targeting c-Met positive tumor cells. Then, water-insoluble Crizotinib-IR808 was fabricated by using bovine serum albumin (BSA) nanoparticles (NPs) with excellent biocompatibility and biosafety. The prepared Crizotinib-IR808@BSA NPs showed tumor targeting capability as well as use for noninvasive biomedical vascular NIR-II imaging with intraoperative real-time NIR-II imaging to guide tumor resection. Under 808 nm laser irradiation, Crizotinib-IR808@BSA NPs exhibited synergistic chemophototherapy effects on tumors. In conclusion, this innovative imaging-mediated multifunctional combination therapy strategy with good c-Met targeting ability may provide a new approach for colorectal cancer treatment.

CD200 in dentate gyrus improves depressive-like behaviors of mice through enhancing hippocampal neurogenesis via alleviation of microglia hyperactivation.

BACKGROUND: Neuroinflammation and microglia play critical roles in the development of depression. Cluster of differentiation 200 (CD200) is an anti-inflammatory glycoprotein that is mainly expressed in neurons, and its receptor CD200R1 is primarily in microglia. Although the CD200-CD200R1 pathway is necessary for microglial activation, its role in the pathophysiology of depression remains unknown. METHODS: The chronic social defeat stress (CSDS) with behavioral tests were performed to investigate the effect of CD200 on the depressive-like behaviors. Viral vectors were used to overexpress or knockdown of CD200. The levels of CD200 and inflammatory cytokines were tested with molecular biological techniques. The status of microglia, the expression of BDNF and neurogenesis were detected with immunofluorescence imaging. RESULTS: We found that the expression of CD200 was decreased in the dentate gyrus (DG) region of mice experienced CSDS. Overexpression of CD200 alleviated the depressive-like behaviors of stressed mice and inhibition of CD200 facilitated the susceptibility to stress. When CD200R1 receptors on microglia were knocked down, CD200 was unable to exert its role in alleviating depressive-like behavior. Microglia in the DG brain region were morphologically activated after exposure to CSDS. In contrast, exogenous administration of CD200 inhibited microglia hyperactivation, alleviated neuroinflammatory response in hippocampus, and increased the expression of BDNF, which in turn ameliorated adult hippocampal neurogenesis impairment in the DG induced by CSDS. CONCLUSIONS: Taken together, these results suggest that CD200-mediated alleviation of microglia hyperactivation contributes to the antidepressant effect of neurogenesis in dentate gyrus in mice.

Novel Structural Design and Adsorption/Insertion Coordinating Quasi-Metallic Na Storage Mechanism toward High-performance Hard Carbon Anode Derived from Carboxymethyl Cellulose.

Hard Carbon have become the most promising anode candidates for sodium-ion batteries, but the poor rate performance and cycle life remain key issues. In this work, N-doped hard carbon with abundant defects and expanded interlayer spacing is constructed by using carboxymethyl cellulose sodium as precursor with the assistance of graphitic carbon nitride. The formation of N-doped nanosheet structure is realized by the CN• or CC• radicals generated through the conversion of nitrile intermediates in the pyrolysis process. This greatly enhances the rate capability (192.8 mAh g-1 at 5.0 A g-1 ) and ultra-long cycle stability (233.3 mAh g-1 after 2000 cycles at 0.5 A g-1 ). In situ Raman spectroscopy, ex situ X-ray diffraction and X-ray photoelectron spectroscopy analysis in combination with comprehensive electrochemical characterizations, reveal that the interlayer insertion coordinated quasi-metallic sodium storage in the low potential plateau region and adsorption storage in the high potential sloping region. The first-principles density functional theory calculations further demonstrate strong coordination effect on nitrogen defect sites to capture sodium, especially with pyrrolic N, uncovering the formation mechanism of quasi-metallic bond in the sodium storage. This work provides new insights into the sodium storage mechanism of high-performance carbonaceous materials, and offers new opportunities for better design of hard carbon anode.

CDK12 and Integrator-PP2A complex modulates LEO1 phosphorylation for processive transcription elongation.

Cyclin-dependent kinase 12 (CDK12) interacts with cyclin K to form a functional nuclear kinase that promotes processive transcription elongation through phosphorylation of the C-terminal domain of RNA polymerase II (Pol II). To gain a comprehensive understanding of CDK12's cellular function, we used chemical genetic and phosphoproteomic screening to identify a landscape of nuclear human CDK12 substrates, including regulators of transcription, chromatin organization, and RNA splicing. We further validated LEO1, a subunit of the polymerase-associated factor 1 complex (PAF1C), as a bona fide cellular substrate of CDK12. Acute depletion of LEO1, or substituting LEO1 phosphorylation sites with alanine, attenuated PAF1C association with elongating Pol II and impaired processive transcription elongation. Moreover, we discovered that LEO1 interacts with and is dephosphorylated by the Integrator-PP2A complex (INTAC) and that INTAC depletion promotes the association of PAF1C with Pol II. Together, this study reveals an uncharacterized role for CDK12 and INTAC in regulating LEO1 phosphorylation, providing important insights into gene transcription and its regulation.

Construction of nano-drug delivery and antitumor system of stimuli-responsive polypeptides.

The size of the nanoparticles is moderate and the dispersion is well, which will not be recognized nonspecifically and clearance by the endothelial reticular system. In this study, stimuli-responsive polypeptides nano-delivery system has been constructed, which can realize the response to various stimuli in the tumor microenvironment. Tertiary amine groups are grafted to the side chain of polypeptides as the point of charge reversal and particle expansion. In addition, a new kind of liquid crystal monomer was prepared by substituting cholesterol-cysteamine, which can promote polymers to realize the transformation of spatial conformation by adjusting the ordered arrangement of macromolecules. The introduction of hydrophobic elements greatly enhanced the self-assembly performance of polypeptides, which could effectively improve the drug loading and encapsulation rate of nanoparticles. Nanoparticles could achieve targeted aggregation in tumor tissues, and there were no toxicity and side effects on normal bodies during treatment, with good safety in vivo.

Construction of poly(amino acid)s nano-delivery system and sustained release with redox-responsive.

A series of novel poly(amino acid)s materials were designed to prepare drug-loaded nanoparticles by physical encapsulation and chemical bonding. The side chain of the polymer contains a large number of amino groups, which effectively increases the loading rate of doxorubicin (DOX). The structure contains disulfide bonds that showing a strong response to the redox environment, which can achieve targeted drug release in the tumor microenvironment. Nanoparticles mainly present spherical morphology with the suitable size for participating in systemic circulation. cell experiments demonstrate the non-toxicity and good cellular uptake behavior of polymers. In vivo anti-tumor experiments shows nanoparticles could inhibit tumor growth and effectively reduce the side effects of DOX.

BNIP3L/NIX-mediated mitophagy alleviates passive stress-coping behaviors induced by tumor necrosis factor-α.

Recent studies based on animal models of various neurological disorders have indicated that mitophagy, a selective autophagy that eliminates damaged and superfluous mitochondria through autophagic degradation, may be involved in various neurological diseases. As an important mechanism of cellular stress response, much less is known about the role of mitophagy in stress-related mood disorders. Here, we found that tumor necrosis factor-α (TNF-α), an inflammation cytokine that plays a particular role in stress responses, impaired the mitophagy in the medial prefrontal cortex (mPFC) via triggering degradation of an outer mitochondrial membrane protein, NIP3-like protein X (NIX). The deficits in the NIX-mediated mitophagy by TNF-α led to the accumulation of damaged mitochondria, which triggered synaptic defects and behavioral abnormalities. Genetic ablation of NIX in the excitatory neurons of mPFC caused passive coping behaviors to stress, and overexpression of NIX in the mPFC improved TNF-α-induced synaptic and behavioral abnormalities. Notably, ketamine, a rapid on-set and long-lasting antidepressant, reversed the TNF-α-induced behavioral abnormalities through activation of NIX-mediated mitophagy. Furthermore, the downregulation of NIX level was also observed in the blood of major depressive disorder patients and the mPFC tissue of animal models. Infliximab, a clinically used TNF-α antagonist, alleviated both chronic stress- and inflammation-induced behavioral abnormalities via restoring NIX level. Taken together, these results suggest that NIX-mediated mitophagy links inflammation signaling to passive coping behaviors to stress, which underlies the pathophysiology of stress-related emotional disorders.

Sustained-release behavior and the antitumor effect of charge-convertible poly(amino acid)s drug-loaded nanoparticles.

Enhancing tissue permeability and achieving drug aggregation is the key to targeted tumor therapy. A series triblock copolymers of poly(ethylene glycol)-poly(L-lysine)-poly(L-glutamine) were synthesized by ring-opening polymerization, and charge-convertible nano-delivery system was constructed by loading doxorubicin (DOX) with 2-(hexaethylimide) ethanol on side chain. In normal environment (pH = 7.4), the zeta potential of the drug-loaded nanoparticle solution is negative, which is conducive to avoiding the identification and clearance of nanoparticles by the reticulo-endothelial system, while potential-reversal can be achieved in the tumor microenvironment, which effectively promotes cellular uptake. Nanoparticles could effectively reduce the distribution of DOX in normal tissues and achieve targeted aggregation at tumor sites, which can effectively improve the antitumor effect, while would not causing toxicity and damage to normal body.

A comprehensive review of the heavy metal issues regarding commercial vanadium­titanium-based SCR catalyst.

Facing the increasing demand of atmosphere pollutant control, selective catalytic reduction (SCR) technology has been widely applied in various industries for NOx abatement. However, in the condition of complicated flue gas components, the heavy metal issue is a great challenge to the catalyst deactivation and atmospheric pollution control. In this review, with the comprehensive consideration of SCR catalysts in heavy metal-rich flue gas scenarios, the distribution character of heavy metals in SCR system is firstly summarized, then the detailed interaction mechanism between heavy metals and the vanadium­titanium-based catalyst is discussed. Focusing on the mercury oxidation as well as against arsenic/lead poisoning, certain modification strategies are also concluded to develop novel SCR catalysts with multiple functions. Furthermore, the state-of-the-art technologies regarding the regeneration, the valuable metal recovery, and the harmless treatment of the spent SCR catalyst are also reported. This paper provides theoretical guidance for the manufacture of novel SCR catalysts under multiple scenarios, as well as the synergistic control of NOx and heavy metals.

Boron-Catalyzed Graphitization Carbon Layer Enabling LiMn0.8 Fe0.2 PO4 Cathode Superior Kinetics and Li-Storage Properties.

The poor electrode kinetics and low conductivity of the LiMn0.8 Fe0.2 PO4 cathode seriously impede its practical application. Here, an effective strategy of boron-catalyzed graphitization carbon coating layer is proposed to stabilize the nanostructure and improve the kinetic properties and Li-storage capability of LiMn0.8 Fe0.2 PO4 nanocrystals for rechargeable lithium-ion batteries. The graphite-like BC3 is derived from B-catalyzed graphitization coating layers, which can not only effectively maintain the dynamic stability of the LiMn0.8 Fe0.2 PO4 nanostructure during cycling, but also plays an important role in enhancing the conductivity and Li+ migration kinetics of LiMn0.8 Fe0.2 PO4 @B-C. The optimized LiMn0.8 Fe0.2 PO4 @B-C exhibits the fastest intercalation/deintercalation kinetics, highest electrical conductivity (8.41 × 10-2 S cm-1 ), Li+ diffusion coefficient (6.17 × 10-12 cm2 s-1 ), and Li-storage performance among three comparison samples (B-C0, B-C6, and B-C9). The highly reversible properties and structural stability of LiMn0.8 Fe0.2 PO4 @B-C are further proved by operando XRD analysis. The B-catalyzed graphitization carbon coating strategy is expected to be an effective pathway to overcome the inherent drawbacks of the high-energy density LiMn0.8 Fe0.2 PO4 cathode and to improve other cathode materials with low-conductivity and poor electrode kinetics for rechargeable second batteries.

Microglia-dependent excessive synaptic pruning leads to cortical underconnectivity and behavioral abnormality following chronic social defeat stress in mice.

Synapse loss in medial prefrontal cortex (mPFC) has been implicated in stress-related mood disorders, such as depression. However, the exact effect of synapse elimination in the depression and how it is triggered are largely unknown. Through repeated longitudinal imaging of mPFC in the living brain, we found both presynaptic and postsynaptic components were declined, together with the impairment of synapse remodeling and cross-synaptic signal transmission in the mPFC during chronic stress. Meanwhile, chronic stress also induced excessive microglia phagocytosis, leading to engulfment of excitatory synapses. Further investigation revealed that the elevated complement C3 during the stress acted as the tag of synapses to be eliminated by microglia. Besides, chronic stress induced a reduction of the connectivity between the mPFC and neighbor regions. C3 knockout mice displayed significant reduction of synaptic pruning and alleviation of disrupted functional connectivity in mPFC, resulting in more resilience to chronic stress. These results indicate that complement-mediated excessive microglia phagocytosis in adulthood induces synaptic dysfunction and cortical hypo-connectivity, leading to stress-related behavioral abnormality.

Highly effective removal of Hg(ii) solution using corn bract@MoS2 as a new biomass adsorbent.

As known, mercury contamination is one of the current environmental issues due to the high toxicity of mercury. Corn bract (CB) is an agricultural by-product, and its final treatment is generally incineration that causes air pollution. In this study, a new type of high-efficiency biomass adsorbent (CB@MoS2) for adsorption of Hg(ii) was obtained, and its morphology and structure were characterized with FT-IR, XRD, SEM and TEM. The results showed that when the pH value, Hg(ii) ion concentration and adsorption time were 4, 100 mg L-1 and 120 min, the adsorption capacity and removal rate could reach 332.50 mg g-1 and 99.75%. In addition, CB@MoS2 had a good selectivity for Hg(ii) ions. The adsorption behavior followed pseudo-second-order kinetics, indicating that the adsorption of Hg(ii) ions by CB@MoS2 was a chemical adsorption. After five adsorption-desorption experiments, it still possessed good adsorption performance and effective regeneration. In short, CB@MoS2 has high efficiency and good reusability, and will become a candidate material for the treatment of mercury-containing industrial wastewater.

Determination of water in organic solvents and raw food products by fluorescence quenching of a crystalline vinyl-functionalized COF.

Covalent organic frameworks (COFs) with good chemical stability, flexible chemical functionalization, tunable pore sizes, and high specific surface areas have been increasingly employed in the field of fluorescence sensing. In this work, a crystalline vinyl-functionalized COF TzDa-V was facilely prepared through a room-temperature synthetic method via condensation reaction between 4,4',4″-(1,3,5-triazine-2,4,6-triyl)trianiline (Tz) and 2,5-diallyloxyterephthalaldehyde (Da-V). The intermolecular charge transfer (ICT) effect endowed the TzDa-V with fluorescence characteristic, and it was sensitive to trace water and can be quenched due to the disruption of ICT process by water. On this base, the prepared COF TzDa-V with excellent chemical/thermal stability was applied to sensing of trace water in common organic solvents such as DMF, acetone, THF, and ethyl acetate with rapid response (less than 10 s), satisfactory sensing range (0.5-18% water in DMF, 0.5-15% water in acetone, 0.5-16% water in THF, 0.5-5% in ethyl acetate, v/v), and high sensitivity. The limits of detection for water in DMF, acetone, THF, and ethyl acetate were 0.0497%, 0.0590%, 0.0502%, and 0.0766% (v/v), respectively. The proposed probe was successfully used for the detection of trace water in food products such as salt and sugar. The COF TzDa-V would be a good candidate for application in water sensing.