Bimetallic Au and Pd Nanoparticles Modified WO3 Nanosheets for Enhancing the Sensitivity and Selectivity of Formaldehyde Assessment in Aquatic Products.

Formaldehyde, a common illegal additive in aquatic products, poses a threat to people's health and lives. In this study, a novel metal oxide semiconductor gas sensor based on AuPd-modified WO3 nanosheets (NSs) had been developed for the highly efficient detection of formaldehyde. WO3 NS modified with 2.0% AuPd nanoparticles showed a higher response (Ra/Rg = 94.2) to 50 ppm of formaldehyde at 210 °C, which was 36 times more than the pristine WO3 NS. In addition, the AuPd/WO3 gas sensor had a relatively short response/recovery time of 10 s/9 s for 50 ppm of formaldehyde at 210 °C, with good immunity to other interfering gases and good stability for formaldehyde. The excellent gas-sensitive performance was attributed to the chemical sensitization of Au, the electronic sensitization of Pd, and the synergistic effect of bimetallic AuPd, which facilitated the recognition and response of formaldehyde molecules. Additionally, the high sensitivity and broad application prospect of the 2.0% AuPd/WO3 NS composite-based sensor in real sample detection were also confirmed by using the above sensor for the detection of formaldehyde in aquatic products such as squid and shrimp.

Enhanced visible light photocatalytic performance of carbon and oxygen co-doped carbon nitride with a three-dimensional structure: Performance and mechanism study.

As a cost-effective photocatalyst, carbon nitride (g-C3N4) holds tremendous promise for addressing energy shortages and environmental pollution. However, its application is limited by disadvantages such as low specific surface area and easy recombination of photogenerated electron-hole pairs. This study introduces C and O co-doped g-C3N4 with a three-dimensional (3D) structure achieved through a straightforward one-step calcination process, demonstrating excellent photocatalytic activity of hydrogen production and oxytetracycline degradation, with superoxide radicals as the primary active species. We propose a plausible enhanced mechanism based on systematic characterizations and density functional theory calculations. The 3D structure confers a substantial specific surface area, enhancing both the adsorption area and active sites of catalysts while bolstering structural stability. Co-doping optimizes the band structure and electric conductivity of the catalyst, facilitating rapid migration of photogenerated charges. The synergistic effects of these enhancements significantly elevate the photocatalytic performance. This study presents a convenient and feasible method for the preparation of dual-regulated photocatalysts with outstanding performance.

H2O2-triggered controllable carbon monoxide delivery for photothermally augmented gas therapy.

Carbon monoxide (CO) gas therapy has shown great potential as a very promising approach in the ongoing fight against tumors. However, delivering unstable CO to the tumor site and safely releasing it for maximum efficacy still have unsatisfactory outcomes. In this study, we've developed nanotheranostics (IN-DPPCO NPs) based on conjugated polymer IN-DPP and carbon monoxide (CO) carrier polymer mPEG(CO) for photothermal augmented gas therapy. The IN-DPPCO NPs can release CO with the hydrogen peroxide (H2O2) overexpressed in the tumor microenvironment. Meanwhile, IN-DPPCO NPs exhibit strong absorption in the near-infrared window, showing a high photothermal conversion efficiency of up to 41.5% under 808 nm laser irradiation. In vitro and in vivo experiments demonstrate that these nanotheranostics exhibit good biocompatibility. Furthermore, the synergistic CO/photothermal therapy shows enhanced therapeutic efficacy compared to gas therapy alone. This work highlights the great promise of conjugated polymer nanoparticles as versatile nanocarriers for spatiotemporally controlled and on-demand delivery of gaseous messengers to achieve precision cancer theranostics.

Controlled synthesis of α-Fe2O3 nanocubes for gas-sensing applications: Feasibility of assessing crucian carp (Carassius auratus) freshness via trimethylamine levels.

Trimethylamine (TMA) is an organic amine with strong pungent smell which is an indicator gas for evaluating fish freshness according to the international standard. In this work, as-synthesize α-Fe2O3 solid nanocubes (NCs), α-Fe2O3 nucleoshell NCs and α-Fe2O3 hollow NCs were used as sensing material to develop an outstanding TMA gas sensor. The response of the α-Fe2O3 hollow NCs sensors towards 20 ppm TMA at 230 ℃ was 6.3. Meanwhile, these sensors showed exceptional response/recovery time, low limit of detection, great selectivity, and outstanding linear relationship. Furthermore, the analysis of gases released during the decomposition of Carassius auratus (0-10 days) was conducted, which demonstrated the assessment of TMA by α-Fe2O3 hollow NCs sensor can evaluate the freshness of Carassius auratus. Such a novel sensor signifies the outstanding application potential in efficient gas-sensing properties of TMA, which will make the tremendous contribution for Carassius auratus product evaluation in the future.

In silico and in vitro analyses of a novel FoxO1 agonist reducing Aß levels via downregulation of BACE1.

AIMS: FoxO1 is an important target in the treatment of Alzheimer's disease (AD). However, FoxO1-specific agonists and their effects on AD have not yet been reported. This study aimed to identify small molecules that upregulate the activity of FoxO1 to attenuate the symptoms of AD. METHODS: FoxO1 agonists were identified by in silico screening and molecular dynamics simulation. Western blotting and reverse transcription-quantitative polymerase chain reaction assays were used to assess protein and gene expression levels of P21, BIM, and PPARγ downstream of FoxO1 in SH-SY5Y cells, respectively. Western blotting and enzyme-linked immunoassays were performed to explore the effect of FoxO1 agonists on APP metabolism. RESULTS: N-(3-methylisothiazol-5-yl)-2-(2-oxobenzo[d]oxazol-3(2H)-yl) acetamide (compound D) had the highest affinity for FoxO1. Compound D activated FoxO1 and regulated the expression of its downstream target genes, P21, BIM, and PPARγ. In SH-SY5Y cells treated with compound D, BACE1 expression levels were downregulated, and the levels of Aß1-40 and Aß1-42 were also reduced. CONCLUSIONS: We present a novel small-molecule FoxO1 agonist with good anti-AD effects. This study highlights a promising strategy for new drug discovery for AD.

Visible light-driven C/O-g-C3N4 activating peroxydisulfate to effectively inactivate antibiotic resistant bacteria and inhibit the transformation of antibiotic resistance genes: Insights on the mechanism.

Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) dissemination within water pose a serious threat to public health. Herein, C and O dual-doped g-C3N4 (C/O-g-C3N4) photocatalyst, fabricated via calcination treatment, was utilized to activate peroxydisulfate (PDS) to investigate the disinfection effect on tetracycline-resistant Escherichia coli and the transformation frequency of ARGs. As a result, approximately 7.08 log E. coli were inactivated, and 72.36 % and 53.96 % of antibiotics resistance gene (tetB) and 16 S rRNA were degraded respectively within 80 min. Futhermore, the transformation frequency was reduced to 0.8. Characterization and theoretical results indicated that C and O doping in g-C3N4 might lead to the electronic structure modulation and band gap energy reduction, resulting in the production of more free radicals. The mechanism analysis revealed that C/O-g-C3N4 exhibited a lower adsorption energy and reaction energy barrier for PDS compared to g-C3N4. This was beneficial for the homolysis of O-O bonds, forming SO4•- radicals. The attack of the generated active species led to oxidative stress in cells, resulting in damage to the electron transport chain and inhibition of ATP production. Our findings disclose a valuable insight for inactivating ARB, and provide a prospective strategy for ARGs dissemination in water contamination.

Design of flavonol-loaded cationic gold nanoparticles with enhanced antioxidant and antibacterial activities and their interaction with proteins.

In this work, four structurally similar flavonols (galangin, kaempferol, quercetin and myricetin) were coated on the surface of (11-mercaptoundecyl)-N,N,N-trimethylammonium bromide (MUTAB)­gold nanoparticles (AuNPs) by two-step phase transfer and self-assembly, and the cationic MUTAB- AuNPs coated with flavonols (flavonol-MUTAB-AuNPs) were designed. Free radical scavenging and antibacterial experiments show that flavonol-MUTAB-AuNPs greatly improve the scavenging effect on DPPH, hydroxyl and superoxide anion radicals, and significantly enhance the inhibition effect on Staphylococcus aureus and Escherichia coli compared with flavonols and AuNPs. Then γ-globulin, fibrinogen, trypsin and pepsin were selected as representative proteins and their interaction with flavonol-MUTAB-AuNPs were investigated by various spectroscopic techniques. The fluorescence quenching mechanism of these four proteins by flavonol-MUTAB-AuNPs is static quenching. The binding constants Ka between them are in the range of 103 to 106. The interaction between them is endothermic, entropy-driven spontaneous process, and the main non-covalent force is the hydrophobic interaction. The effect of flavonol-MUTAB-AuNPs on the structure of the four proteins were investigated using UV-vis absorption spectra, synchronous fluorescence spectra and circular dichroism spectra. These results offer important insights into the essence of the interaction between flavonol-MUTAB-AuNPs and γ-globulin/fibrinogen/trypsin/pepsin. They will contribute to the development of safe and effective flavonol-MUTAB-AuNPs in biomedical fields.

NIR-II Absorbing Conjugated Polymer Nanotheranostics for Thermal Initiated NO Enhanced Photothermal Therapy.

Photothermal therapy (PTT) has received constant attention as a promising cancer treatment. However, PTT-induced inflammation can limit its effectiveness. To address this shortcoming, we developed second near-infrared (NIR-II) light-activated nanotheranostics (CPNPBs), which include a thermosensitive nitric oxide (NO) donor (BNN6) to enhance PTT. Under a 1064 nm laser irradiation, the conjugated polymer in CPNPBs serves as a photothermal agent for photothermal conversion, and the generated heat triggers the decomposition of BNN6 to release NO. The combination of hyperthermia and NO generation under single NIR-II laser irradiation allows enhanced thermal ablation of tumors. Consequently, CPNPBs can be exploited as potential candidates for NO-enhanced PTT, holding great promise for their clinical translational development.

Facile fabrication of 3D hollow porous aminopyridine rings decorated polymeric carbon nitride for enhanced photocatalytic hydrogen evolution and dye elimination.

In consideration of energy shortages and environmental pollution, there is a critical need to develop a photocatalyst with high catalytic performance for rapid hydrogen production and efficient pollutant degradation. We synthesized a photocatalytic composite catalyst with three-dimensional (3D) porous aminopyridine rings grafted on the edge of g-C3N4 (APCN) using melamine, cyanuric acid and 4-aminopyridine as raw materials. The composite catalyst exhibited excellent photocatalytic performance for H2 production (2.44 mmol g-1h-1) and RhB degradation (97.08%) under visible light. Subsequently, a possible enhanced mechanism of the catalyst was proposed on the basis of a series of characterization and photocatalytic experiments. The 3D porous structure not only enhanced the structural stability but also increased the surface area of the APCN catalysts, which generated more exposed active sites. Moreover, the aminopyridine ring embellishment was beneficial for achieving a narrowed bandgap and charge migration and separation, which decreased the occurrence of photogenerated carrier recombination. In summary, these two structural features showed a synergistic effect to enhance the photocatalytic performance of the APCN catalyst. Finally, an integrated feasible enhanced mechanism of photocatalytic activity was elucidated according to the results of active substance capture tests, showing that O2•- played an important role during RhB degradation.

Antipsychotics-induced improvement of cool executive function in individuals living with schizophrenia.

Cool executive dysfunction is a crucial feature in people living with schizophrenia which is related to cognition impairment and the severity of the clinical symptoms. Based on electroencephalogram (EEG), our current study explored the change of brain network under the cool executive tasks in individuals living with schizophrenia before and after atypical antipsychotic treatment (before_TR vs. after_TR). 21 patients with schizophrenia and 24 healthy controls completed the cool executive tasks, involving the Tower of Hanoi Task (THT) and Trail-Marking Test A-B (TMT A-B). The results of this study uncovered that the reaction time of the after_TR group was much shorter than that of the before_TR group in the TMT-A and TMT-B. And the after_TR group showed fewer error numbers in the TMT-B than those of the before_TR group. Concerning the functional network, stronger DMN-like linkages were found in the before_TR group compared to the control group. Finally, we adopted a multiple linear regression model based on the change network properties to predict the patient's PANSS change ratio. Together, the findings deepened our understanding of cool executive function in individuals living with schizophrenia and might provide physiological information to reliably predict the clinical efficacy of schizophrenia after atypical antipsychotic treatment.

A bioinspired polydopamine-FeS nanocomposite with high antimicrobial efficiency via NIR-mediated Fenton reaction.

Ferrous and sulfur ions are essential elements for the human body, which play an active role in maintaining the body's normal physiology. Meanwhile, mussel-inspired polydopamine (PDA) possesses good hydrophilicity and biocompatibility. In the present work, ferrous sulfide embedded into polydopamine nanoparticles (PDA@FeS NPs) was designed and synthesized via a simple predoping polymerization-coprecipitation strategy and the intelligent PDA matrix successfully prevented the oxidation and agglomeration of FeS nanoparticles. Importantly, there was an obvious synergistic enhancement of the photothermal effect between polydopamine and ferrous sulfide. The PDA@FeS NPs exhibited excellent photothermal antibacterial effects against both E. coli and S. aureus. The near-infrared (NIR) light-mediated release of ferrous ions could reach about 26.5% under weakly acidic conditions, further triggering the Fenton reaction to produce toxic hydroxyl radicals (·OH) in the presence of hydrogen peroxide. The antibacterial mechanism could be attributed to cell membrane damage and cellular content leakage with the synergistic effect of PTT and CDT. This study highlighted the germicidal efficacy of PDA@FeS NPs and provided a new strategy for designing and developing next-generation antibacterial platforms.

A NIR fluorescence probe for monitoring Cys upregulation induced by balsam pear polysaccharide and imaging in zebrafish.

In this work, we introduced the acrylate recognition group into dicyanoisophorone derivative DCI-C-OH to construct the NIR fluorescent probe DCI-C-Cys with a large Stokes shift (240 nm). DCI-C-Cys could specifically respond to Cys, resulting in a 22-fold increase in fluorescence intensity at 702 nm. Meanwhile, the probe has the advantages of good water solubility, high sensitivity (93 nM), and excellent biocompatibility. Moreover, DCI-C-Cys successfully monitored endogenous and exogenous Cys in HepG2 cells and zebrafish. Most importantly, we found that balsam pear polysaccharide could lead to the increase of intracellular Cys levels, which might be conducive to the further study of the antioxidant mechanism of balsam pear polysaccharide.

Enhanced adsorption and catalytic degradation of antibiotics by porous 0D/3D Co3O4/g-C3N4 activated peroxymonosulfate: An experimental and mechanistic study.

In this work, Co3O4/g-C3N4 catalyst with highly efficient adsorption and degradation of antibiotics was developed based on the combination of three-dimensional (3D) porous morphological controls of g-C3N4 and the loading of Co3O4 quantum dots (Co3O4 QDs). It was discovered that the catalyst can effectively activate peroxymonosulfate (PMS) through a non-photochemical path, and a high tetracycline elimination rate of 99.7% can be achieved within 18 min. The characterization and density functional theory calculation results demonstrated that the porous 3D structure can not only promote the substrate adsorption reaction but also provide large surface area and countless exposed active sites for catalytic reaction. The introduction of Co3O4 QDs lowered activation energy barrier and lead to high energy of PMS adsorption. More efficient charge migration between the catalyst and PMS further accelerated PMS activation. Thus, leading to the excellent catalytic performance. In addition, non-free radical mediated degradation mechanism of catalytic activity was also proposed. This work provides a scheme for designing novel and efficient PMS activators for the removal of abusive antibiotics from aqueous environments.

Abnormal brain gray matter volume in patients with major depressive disorder: Associated with childhood trauma?

BACKGROUND: Patients with major depressive disorders (MDD) have abnormalities in the frontal-limbic structures of the brain. Childhood trauma is a risk factor for both structural brain alterations and MDD. However, the relationships among the three have not been confirmed. METHODS: Sixty-four patients with MDD and sixty-one healthy controls (HC) were checked by using MRI, the Hamilton Depression Scale (HAMD) and Childhood Trauma Questionnaire (CTQ). Voxel-based morphometry (VBM) was used to compare gray matter volume (GMV) differences between the two groups. Moreover, partial correlation and mediation analyses were conducted to test for potential associations between CTQ scores, different GMV, and clinical variables. RESULTS: Compared to the HC group, the MDD patients showed decreased GMV in the right middle frontal gyrus (rMFG) and right precentral gyrus (rPreCG). In the patient group, reduced GMV in rMFG was associated with CTQ scores (r = -0.30, P = 0.019) and HAMD scores (r = -0.53, P < 0.001). Finally, in the patient group, mediation analysis revealed that the indirect effect of rMFG GMV in CTQ scores and HAMD scores was 0.115 and the proportion of indirect effect to total effect was 23.86%. LIMITATIONS: This study used a cross-sectional collection, and it is unclear whether at the longitudinal level the brain GMV mediates the relationship between childhood trauma and depression. CONCLUSIONS: Abnormalities in the frontal GMV were presented in the MDD patients. It is possible that childhood traumatic experiences cause inefficient GMV and ultimately lead to an increased susceptibility to depression.

Peroxymonosulfate activation by Co3O4/SnO2 for efficient degradation of ofloxacin under visible light.

In this work, Co3O4/SnO2 catalyst was prepared by a one-pot hydrothermal method and applied in the activation of peroxymonosulfate (PMS) for the degradation of the target pollutant ofloxacin (OFX). The results showed that the PMS/Co3O4/SnO2-8% system had a 92% OFX degradation efficiency after 30 min of catalytic reaction, which was 46 times higher than that of PMS/SnO2 alone, and the degradation efficiency could be maintained in a wide pH range (5-11). In addition, reactive oxygen species quenching experiments and electron spin resonance spectra confirmed that sulfate radicals, superoxide radicals, hydroxyl radicals and singlet oxygen were the dominant active groups. The excellent recyclability and stability of the as-prepared catalyst were confirmed by cycling experiments and characterization results. Finally, a possible degradation pathway of OFX was suggested, and the intermediate toxicity of this system was identified and analyzed by a quantitative structure-activity relationship (QSAR).

The interaction mechanism between gold nanoparticles and proteins: Lysozyme, trypsin, pepsin, γ-globulin, and hemoglobin.

In this study, the interaction between gold nanoparticles (AuNPs) and proteins (including lysozyme, trypsin, pepsin, γ-globulin and hemoglobin) was investigated by UV-visible absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy and protein activity assay. AuNPs was synthesized using reduction of HAuCl4 with sodium citrate. The formation of AuNPs was confirmed from the characteristic surface plasmon resonance band at 521 nm and transmission electron microscopy revealed the average particle size was about 10 nm. The results reveal that AuNPs can interact with proteins to form a "protein corona (PC)", but the protein concentration required to form a relatively stable PC is not the same. The quenching mechanism of proteins by AuNPs is arisen from static quenching. The binding constants of AuNPs with proteins are in the range from 106 to 1010 L mol-1, and the order is pepsin > Î³-globulin > hemoglobin > trypsin > lysozyme at 298 K. Van der Waals forces and hydrogen bonds are the main forces for the lysozyme-AuNPs system. The interaction between trypsin/pepsin/γ-globulin/hemoglobin and AuNPs is mainly by hydrophobic interaction. The addition of AuNPs has an effect on the secondary structure of proteins as confirmed from CD spectra. The change in secondary structure of different proteins is different and seems to have little relation with the binding constant. The activity of lysozyme/trypsin/pepsin decreases with the addition of AuNPs.

Promoting the anode performance of microbial fuel cells with nano-molybdenum disulfide/carbon nanotubes composite catalyst.

The design and manufacture of advanced anode materials with superior quality are significant for assembling high-performance microbial fuel cells (MFCs). The present study aims to investigate the synergistic effect of MoS2/CNTs nanocomposite as a novel anode-modifying material of MFCs. XRD, XPS, SEM, TEM and electrochemical analyses were performed to confirm the nanocomposite, to understand the morphology and to study the electrochemical properties of the modified electrodes. The performance of the MoS2/CNTs/carbon paper (CP)-MFCs was investigated and compared with that of MoS2/CP-MFCs, CNTs/CP-MFCs and CP-MFCs. The densest biofilm was formed on MoS2/CNTs-modified anode compared to MoS2/CP, CNTs/CP and CP anode, and MFCs with MoS2/CNTs-modified anodes achieved the maximum power density of 645 ± 32 mW m-2, which is three times greater than MFCs with bare carbon paper anodes (213 ± 10 mW m-2). These results demonstrate that the synthesized MoS2/CNTs nanocomposite could be exploited as an efficient anode catalyst for improving the performance of MFCs.

Physalin B reduces Aß secretion through down-regulation of BACE1 expression by activating FoxO1 and inhibiting STAT3 phosphorylation.

Physalin B (PB), one of the major active steroidal constituents of Solanaceae Physalis plants, has a wide variety of biological activities. We found that PB significantly down-regulated ß-amyloid (Aß) secretion in N2a/APPsw cells. However, the underlying mechanisms are not well understood. In the current study, we investigated the changes in key enzymes involved in ß-amyloid precursor protein (APP) metabolism and other APP metabolites by treating N2a/APPsw cells with PB at different concentrations. The results indicated that PB reduced Aß secretion, which was caused by down-regulation of ß-secretase (BACE1) expression, as indicated at both the protein and mRNA levels. Further research revealed that PB regulated BACE1 expression by inducing the activation of forkhead box O1 (FoxO1) and inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). In addition, the effect of PB on BACE1 expression and Aß secretion was reversed by treatment with FoxO1 siRNA and STAT3 antagonist S3I-201. In conclusion, these data demonstrated that PB can effectively down-regulate the expression of BACE1 to reduce Aßsecretion by activating the expression of FoxO1 and inhibiting the phosphorylation of STAT3.

Comparative study on the interaction between flavonoids with different core structures and hyaluronidase.

Hyaluronidase (HAase) is an important enzyme involved in a promoting inflammation pathway. Flavonoids are a group of major polyphenols including flavonols (such as myricetin and rutin), dihydroflavones (such as naringin and hesperidin), and isoflavones (such as genistein and puerarin), which have been proved to possess anti-inflammatory effects. In this study, the binding of the six flavonoids to HAase was investigated by steady state and time-resolved fluorescence, circular dichroism (CD) spectroscopy and molecular docking methods. Fluorescence data reveal that the fluorescence quenching mechanism of HAase by flavonoids is all static quenching procedure regardless of their core structure. The binding affinity is strongest for rutin and ranks in the order rutin > hesperidin > myricetin > puerarin > genistein > naringin. The thermodynamic analysis implies that hydrophobic interaction, electrostatic force and hydrogen bonding are the main interaction forces. Synchronous fluorescence spectroscopy and CD spectroscopy indicate that flavonoids have the same core structure and have similar effects on the microenvironment around Trp and Tyr residues and the secondary structure of HAase. The results of molecular docking show that the binding of flavonoids with the catalytic amino acid residues of HAase may lead to the decrease of enzyme activity.