Operando identification of the oxide path mechanism with different dual-active sites for acidic water oxidation.

The microscopic reaction pathway plays a crucial role in determining the electrochemical performance. However, artificially manipulating the reaction pathway still faces considerable challenges. In this study, we focus on the classical acidic water oxidation based on RuO2 catalysts, which currently face the issues of low activity and poor stability. As a proof-of-concept, we propose a strategy to create local structural symmetry but oxidation-state asymmetric Mn4-δ-O-Ru4+δ active sites by introducing Mn atoms into RuO2 host, thereby switching the reaction pathway from traditional adsorbate evolution mechanism to oxide path mechanism. Through advanced operando synchrotron spectroscopies and density functional theory calculations, we demonstrate the synergistic effect of dual-active metal sites in asymmetric Mn4-δ-O-Ru4+δ microstructure in optimizing the adsorption energy and rate-determining step barrier via an oxide path mechanism. This study highlights the importance of engineering reaction pathways and provides an alternative strategy for promoting acidic water oxidation.

Engineering Yarrowia lipolytica for Efficient Synthesis of Geranylgeraniol.

Geranylgeraniol (GGOH) is a crucial component in fragrances and essential oils, and a valuable precursor of vitamin E. It is primarily extracted from the oleoresin of Bixa orellana, but is challenged by long plant growth cycles, severe environmental pollution, and low extraction efficiency. Chemically synthesized GGOH typically comprises a mix of isomers, making the separation process both challenging and costly. Advancements in synthetic biology have enabled the construction of microbial cell factories for GGOH production. In this study, Yarrowia lipolytica was engineered to efficiently synthesize GGOH by expressing heterologous phosphatase genes, enhancing precursor supplies of farnesyl diphosphate, geranylgeranyl pyrophosphate, and acetyl-CoA, and downregulating the squalene synthesis pathway by promoter engineering. Additionally, optimizing fermentation conditions and reducing reactive oxygen species significantly increased the GGOH titer to 3346.47 mg/L in a shake flask. To the best of our knowledge, this is the highest reported GGOH titer in shaking flasks to date, setting a new benchmark for terpenoid production.

A highly sensitive SERS sensor based on PVDF/Au nanofibers for trace analysis of nitrite ions.

Nitrite ions present a significant risk to both environmental and human health, necessitating precise and sensitive detection methods. Herein, we fabricated a highly sensitive SERS sensor based on PVDF/Au nanofibers for nitrite ion detection. The synthesis of PVDF nanofibers involved the utilization of electrospinning apparatus, while the uniformity and high density of SERS activity "hot spots" were achieved by directly coating plasma gold nanoparticles onto the PVDF surface adopting thermal evaporation. The efficient charge transfer of the interface dipole layer directly generated on the surface of PVDF nanofibers was achieved through thermal evaporation. The enhanced Raman responses were due to the combined effects of local surface plasmon resonance of Au nanoparticles and photoelectric and piezoelectric properties of PVDF. It is noteworthy that the prepared SERS substrate exhibited high sensitivity towards rhodamine 6G, boasting an enhancement factor of 9.4 × 107 and a detection limit spanning from 10-6-10-11 M. Furthermore, the PVDF/Au membrane functionalized with p-aminothiophenol (PATP) effectively captured NO2- ions at concentrations as low as 10-8 M and successfully detected NO2- in river water samples. Additionally, the SERS substrate has good repeatability and stability, and can be applied to trace detection in food safety and medical diagnosis.

Impact of Right Ventricular Pressure Overload on Myocardial Stiffness Assessed by Natural Wave Imaging.

BACKGROUND: Right ventricular (RV) hemodynamic performance determines the prognosis of patients with RV pressure overload. Using ultrafast ultrasound, natural wave velocity (NWV) induced by cardiac valve closure was proposed as a new surrogate to quantify myocardial stiffness. OBJECTIVES: This study aimed to assess RV NWV in rodent models and children with RV pressure overload vs control subjects and to correlate NWV with RV hemodynamic parameters. METHODS: Six-week-old rats were randomized to pulmonary artery banding (n = 6), Sugen hypoxia-induced pulmonary arterial hypertension (n = 7), or sham (n = 6) groups. They underwent natural wave imaging, echocardiography, and hemodynamic assessment at baseline and 6 weeks postoperatively. The authors analyzed NWV after tricuspid and after pulmonary valve closure (TVC and PVC, respectively). Conductance catheters were used to generate pressure-volume loops. In parallel, the authors prospectively recruited 14 children (7 RV pressure overload; 7 age-matched control subjects) and compared RV NWV with echocardiographic and invasive hemodynamic parameters. RESULTS: NWV significantly increased in RV pressure overload rat models (4.99 ± 0.27 m/s after TVC and 5.03 ± 0.32 m/s after PVC in pulmonary artery banding at 6 weeks; 4.89 ± 0.26 m/s after TVC and 4.84 ± 0.30 m/s after PVC in Sugen hypoxia at 6 weeks) compared with control subjects (2.83 ± 0.15 m/s after TVC and 2.72 ± 0.34 m/s after PVC). NWV after TVC correlated with both systolic and diastolic parameters including RV dP/dtmax (r = 0.75; P < 0.005) and RV Ees (r = 0.81; P < 0.005). NWV after PVC correlated with both diastolic and systolic parameters and notably with RV end-diastolic pressure (r = 0.65; P < 0.01). In children, NWV after both right valves closure in RV pressure overload were higher than in healthy volunteers (P < 0.01). NWV after PVC correlated with RV E/E' (r = 0.81; P = 0.008) and with RV chamber stiffness (r = 0.97; P = 0.03). CONCLUSIONS: Both RV early-systolic and early-diastolic myocardial stiffness show significant increase in response to pressure overload. Based on physiology and our observations, early-systolic myocardial stiffness may reflect contractility, whereas early-diastolic myocardial stiffness might be indicative of diastolic function.

Inhibition of MRTF-A Ameliorates Pathological Remodeling of the Pressure-loaded Right Ventricle.

Right ventricular (RV) fibrosis is associated with RV dysfunction in a variety of RV pressure-loading conditions where RV mechanical stress is increased, but the underlying mechanisms driving RV fibrosis are incompletely understood. In pulmonary and cardiovascular diseases characterized by elevated mechanical stress and transforming growth factor - beta-1 (TGF-ß1) signaling, myocardin-related transcription factor A (MRTF-A) is a mechanosensitive protein critical to driving myofibroblast transition and fibrosis. Here we investigated whether MRTF-A inhibition improves RV pro-fibrotic remodeling and function in response to a pulmonary artery banding (PAB) model of RV pressure-loading. Rats were assigned into either 1) sham or 2) PAB groups. MRTF-A inhibitor CCG-1423 was administered daily at 0.75mg/kg in a subset of PAB animals. Echocardiography and pressure-volume hemodynamics were obtained at a terminal experiment 6-weeks later. RV myocardial samples were analyzed for fibrosis, cardiomyocyte hypertrophy, and pro-fibrotic signaling. MRTF-A inhibition slightly reduced systolic dysfunction in PAB rats reflected by increased lateral tricuspid annulus peak systolic velocity, while diastolic function parameters were not significantly improved. RV remodeling was attenuated in PAB rats with MRTF-A inhibition, displaying reduced fibrosis. This was accompanied with a reduction in PAB-induced upregulation of yes-associated protein (YAP) and its paralog transcriptional co-activator with PDZ-binding motif (TAZ). We also confirmed using a second-generation MRTF-A inhibitor CCG-203971 that MRTF-A is critical in driving RV fibroblast expression of TAZ and markers of myofibroblast transition in response to TGF-ß1 stress and RhoA activation. These studies identify RhoA, MRTF-A, and YAP/TAZ as interconnected regulators of pro-fibrotic signaling in RV pressure-loading, and as potential targets to improve RV pro-fibrotic remodeling.

Predicting lymphoma prognosis using machine learning-based genes associated with lactylation.

BACKGROUND: Lactylation, a newly discovered PTM involving lactic acid, is linked to solid tumor proliferation and metastasis. Lymphoma patients exhibit high lactic acid levels, yet lactylation's role in lymphoma is underexplored. This study aimed to identify lactylation-related genes in lymphoma using tumor databases and assess their predictive value in patient prognosis through cell experiments and clinical specimens. METHODS: Using TCGA and GEO datasets, we analyzed the expression levels of lactylation-related genes in diffuse large B-cell lymphoma patients. We also evaluated the prognostic significance of lactylation gene risk scores, exploring their impact on drug sensitivity and tumor immune function. Key lactylation-affecting genes were identified and functionally validated through cell experiments and mouse in vivo experiments. Additionally, the relationship between lactylation and lymphoma prognosis was examined in clinical specimens. RESULTS: We identified 70 genes linked to diffuse large B-cell lymphoma prognosis from the lactylation-related gene set. Using clinical data and a COX regression algorithm, we developed an optimized lactylation Riskscore model. This model significantly correlated with prognosis and showed differences in immune cell infiltration, particularly macrophages. High-risk patients showed resistance to chemotherapy drugs but responded well to immunotherapy. HNRNPH1, a lactylation-related gene, influenced patient prognosis, apoptosis, cell cycle distribution in lymphoma cells, and tumor volume in mice. In lymphoma specimens, lactylation levels correlated with Bcl-2, C-myc, and P53 levels. CONCLUSIONS: Lactylation impacts diffuse large B-cell lymphoma prognosis, tumor immune function, and drug resistance. Our lactylation-based Riskscore model aids in patient stratification and treatment selection. HNRNPH1 regulates lactylation, thereby affecting patient prognosis.

Phospho-code of a conserved transcriptional factor underpins fungal virulence.

BACKGROUND: Cell wall integrity (CWI) is crucial for fungal growth, pathogenesis, and adaptation to extracellular environments. Calcofluor white (CFW) is a cell wall perturbant that inhibits fungal growth, yet little is known about how phytopathogenic fungi respond to the CFW-induced stress. RESULTS: In this study, we unveiled a significant discovery that CFW triggered the translocation of the transcription factor CgCrzA from the cytoplasm to the nucleus in Colletotrichum gloeosporioides. This translocation was regulated by an interacting protein, CgMkk1, a mitogen-activated protein kinase involved in the CWI pathway. Further analysis revealed that CgMkk1 facilitated nuclear translocation by phosphorylating CgCrzA at the Ser280 residue. Using chromatin immunoprecipitation sequencing, we identified two downstream targets of CgCrzA, namely CgCHS5 and CgCHS6, which are critical for growth, cell wall integrity, and pathogenicity as chitin synthase genes. CONCLUSIONS: These findings provide a novel insight into the regulatory mechanism of CgMkk1-CgCrzA-CgChs5/6, which enables response of the cell wall inhibitor CFW and facilitates infectious growth for C. gloeosporioides.

Molecular insights into the catalytic mechanism of a phthalate ester hydrolase.

Phthalate esters (PAEs) are emerging hazardous and toxic chemicals that are extensively used as plasticizers or additives. Diethyl phthalate (DEP) and dimethyl phthalate (DMP), two kinds of PAEs, have been listed as the priority pollutants by many countries. PAE hydrolases are the most effective enzymes in PAE degradation, among which family IV esterases are predominate. However, only a few PAE hydrolases have been characterized, and as far as we know, no crystal structure of any PAE hydrolases of the family IV esterases is available to date. HylD1 is a PAE hydrolase of the family IV esterases, which can degrade DMP and DEP. Here, the recombinant HylD1 was characterized. HylD1 maintained a dimer in solution, and functioned under a relatively wide pH range. The crystal structures of HylD1 and its complex with monoethyl phthalate were solved. Residues involved in substrate binding were identified. The catalytic mechanism of HylD1 mediated by the catalytic triad Ser140-Asp231-His261 was further proposed. The hylD1 gene is widely distributed in different environments, suggesting its important role in PAEs degradation. This study provides a better understanding of PAEs hydrolysis, and lays out favorable bases for the rational design of highly-efficient PAEs degradation enzymes for industrial applications in future.

Corrigendum: Effects of Caragana korshinskii tannin on fermentation, methane emission, community of methanogens, and metabolome of rumen in sheep.

[This corrects the article DOI: 10.3389/fmicb.2024.1334045.].

The influencing factors of stigma towards people with mental illness among nursing students: a mixed-method systematic review.

The stigma of nursing students towards people with mental illness (PMI) creates significant barriers to diagnosis, treatment, and recovery for those with PMI. It can also have a significant impact on the future career choices of nursing students in the field of psychiatry. Current research has found various influencing factors, including personal characteristics and educational influences. However, a comprehensive analysis that encompasses all aspects is lacking. The aim of the study was to conduct a convergent mixed-method systematic review to synthesize the influencing factors of the stigma of nursing students towards PMI according to Framework Integrating Normative Influences on Stigma (FINIS) at micro, meso, and macro levels. PubMed, Web of Science, Cochrane Library, EMBASE, CINAHL and PsycINFO were searched from 1990 to 31 December 2023. The reference lists of the included literature were further checked to identify potentially relevant articles. Two authors independently screened all titles, abstracts, and full-text articles and extracted data. Study quality was assessed by two authors using the Mixed Method Appraisal Tool (MMAT). A total of 4865 articles were initially retrieved, and 73 of these articles were included. The results suggested that the stigma towards PMI by nursing students was influenced by micro, meso and macro levels. At each FINIS level, the most frequent influencing factors are personal characteristics, the treatment system and media images. Numerous interconnected factors exert an influence on the stigma towards PMI among nursing students. Our research can be used to identify barriers and facilitators to nursing students' stigma towards PMI and to provide supporting information for interventions designed to reduce this stigma.

Eating Styles Profiles and Correlates in Chinese Postpartum Women: A Latent Profile Analysis.

Postpartum women present a high risk of disordered eating behaviors, but the heterogeneity between groups was not identified. This cross-sectional study aimed to identify eating styles profiles in postpartum women and explore the correlates based on demographic characteristics and psychosocial factors. Questionnaires were administered to 507 Chinese postpartum women. Latent profile analysis (LPA) was conducted to identify eating styles profiles. Multinomial logistic regression was used to investigate the correlates of these profiles among postpartum women. The LPA identified three eating styles profiles: postpartum women with low emotional, external, and restrained eating (Profile 1, 6.9%); postpartum women with medium emotional, external, and restrained eating (Profile 2, 66.1%); and postpartum women with high emotional, external, and restrained eating (Profile 3, 27.0%). Compared to Profile 1, higher postpartum depression (PPD) and body mass index (BMI) were more likely to be associated with Profile 2 and Profile 3, whereas higher postpartum weight retention (PPWR) was more likely to be associated with Profile 1. Compared to Profile 2, higher PPD and BMI were more likely associated with Profile 3. Disordered eating behaviors in postpartum women with three eating styles were associated with BMI, PPD, and PPWR. This study can guide healthcare professionals in developing targeted interventions to improve maternal and child health globally.

Atroposelective Formal [2 + 5] Macrocyclization Synthesis for a Novel All-Hydrocarbon Cyclo[7] Meta-Benzene Macrocycle.

A novel axially chiral all-hydrocarbon cyclo[7] (1,3-(4,6-dimethyl)benzene (CDMB-7) was designed and synthesized using atroposelective[2 + 5] cyclization through Suzuki-Miyaura coupling. CDMB-7 adopts an irregular bowl-like shape with C2 symmetry and exhibits two diastereoisomers in its crystallographic structure. The conformational isomers of CDMB-7 racemates remain stable at high temperatures (393 K). High-performance liquid chromatography (HPLC) confirmed that a single chiral isomer will spontaneously undergo racemization within 30 min at room temperature. This finding opens up possibilities for achieving adaptive chirality in all-hydrocarbon cyclo[7] m-benzene macrocycles.

Study of the multitarget mechanism of Astragalus (HUANGQI) in the treatment of Alzheimer's disease based on network pharmacology and molecular docking technology.

CONTEXT: In China, HUANGQI is widely used for the treatment of Alzheimer's disease (AD). However, a comprehensive understanding of its mechanism of anti-AD effects is lacking. OBJECTIVE: To explore the active ingredients of HUANGQI and its potential targets and mechanisms of action in AD. MATERIALS AND METHODS: The active ingredients and targets of HUANGQI were screened from databases (TCSMP, ETCM, and BATMan), and AD-related genes were obtained from DrugBank and GeneCards. The same target genes were screened, and a drug-target disease network was constructed. The PPI network was constructed and GO and KEGG pathway enrichment analyses of the targets. The Cell Counting Kit-8 (CCK-8) assay was used to determine suitable HUANGQI treatment concentrations for HT-22 cells between 0-480 µg/mL. CCK-8, FITC-phalloidin and propidium iodide (PI) assays were used to examine the protective effect of (0, 60, 120, 240 µg/mL) of HUANGQI on 20 µM Aß1-42-induced HT-22 cell cytotoxicity. RESULTS: Twelve active ingredients of HUANGQI were selected, with 679 common targets associated with AD. GO and KEGG analysis revealed that the therapeutic mechanisms of HUANGQI involve TNF, AGE, the NF-κB pathway, and nuclear receptor activity-related processes. The CCK-8 assay indicated that HUANGQI was not cytotoxic to HT-22 cells at concentrations less than 240 µg/mL and was able to attenuate Aß1-42-induced cellular damage (EC50 = 83.46 µg/mL). FITC-phalloidin and PI assays suggested that HUANGQI could alleviate 20 µM Aß1-42-induced neuronal cell cytotoxicity in a dose-dependent manner. CONCLUSION: HUANGQI has a protective effect on Aß1-42-induced nerve cell injury; further mechanism research was needed.

Reconstructing a 300-year history of phosphorus cycle in west Chaohu Lake, China.

Anthropogenic activities could significantly increase nutrients loading, especially phosphorus (P), into aquatic systems, leading to eutrophication and disturbance of ecosystems. Detailed investigation of P cycling and its controlling factors in modern lakes could help understand mechanisms behind eutrophication, thus provide suggestions for future environmental management. Here, we investigate evolution history of P and iron (Fe) cycling over the last ∼300 years in west Chaohu Lake, a typical eutrophic lake in East China. The combination of 210Pb-137Cs dating and elemental analysis demonstrates drastic escalation of P input and organic carbon burial since 1960s, coincided with the rapid growth of human population near this region. P phase partitioning data indicate that Fe-bound P (PFe) is the predominant P pool of sediments in Chaohu Lake, which also regulates the evolving trend of reactive P (Preac). Moreover, the highest fraction of PFe is consistent with observations via P K-edge X-ray absorption near edge structure (P XANES). In addition, Fe speciation results show a principal contribution of Fe (hydr)oxides (Feox) and negligible presence of pyrite, suggesting a generally oxygenated depositional environment, where P could be preferentially sequestrated in sediments in association with Fe oxide minerals. Relatively high molar organic carbon/organic P (Corg/Porg) but low Corg/Preac ratios also support limited recycling of Preac in west Chaohu Lake. This study reveals that human activities play an important role in leading to the eutrophication of Chaohu Lake. Future environmental management could utilize the coupling of P and Fe oxides to remove P from water column.

The Potential Mechanism of Eriodictyol in Treating Alzheimer's Disease: A Study on Computer-assisted Investigational Strategies.

BACKGROUND: At present, drug development for treating Alzheimer's disease (AD) is still highly challenging. Eriodictyol (ERD) has shown great potential in treating AD, but its molecular mechanism is unknown. OBJECTIVE: We aimed to explore the potential targets and mechanisms of ERD in the treatment of AD through network pharmacology, molecular docking, and molecular dynamics simulations. METHODS: ERD-related targets were predicted based on the CTD, SEA, PharmMapper, Swiss TargetPrediction, and ETCM databases, and AD-related targets were predicted through the TTD, OMIM, DrugBank, GeneCards, Disgenet, and PharmGKB databases. Protein-protein interaction, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomics analyses (KEGG) were used to analyse the potential targets and key pathways of the anti-AD effect of ERD. Subsequently, potential DEGs affected by AD were analysed using the AlzData database, and their relationships with ERD were evaluated through molecular docking and molecular dynamics simulations. RESULTS: A total of 198 ERD-related targets, 3716 AD-related targets, and 122 intersecting targets were identified. GO annotation analysis revealed 1497 biological processes, 78 cellular components, and 132 molecular functions of 15 core targets. KEGG enrichment analysis identified 168 signalling pathways. We ultimately identified 9 DEGs associated with AD through analysis of the AlzData data. Molecular docking results showed good affinity between the selected targets and ERD, with PTGS2, HSP90AA1, and BCL2. The interactions were confirmed by molecular dynamics simulations. CONCLUSION: ERD exerts anti-AD effects through multiple targets, pathways, and levels, providing a theoretical foundation and valuable reference for the development of ERD as a natural anti-AD drug.

Edge-Rich Pt-O-Ce Sites in CeO2 Supported Patchy Atomic-Layer Pt Enable a Non-CO Pathway for Efficient Methanol Oxidation.

Rational design of efficient methanol oxidation reaction (MOR) catalyst that undergo non-CO pathway is essential to resolve the long-standing poisoning issue. However, it remains a huge challenge due to the rather difficulty in maximizing the non-CO pathway by the selective coupling between the key *CHO and *OH intermediates. Here, we report a high-performance electrocatalyst of patchy atomic-layer Pt epitaxial growth on CeO2 nanocube (Pt ALs/CeO2) with maximum electronic metal-support interaction for enhancing the coupling selectively. The small-size monolayer material achieves an optimal geometrical distance between edge Pt-O-Ce sites and *OH absorbed on CeO2, which well restrains the dehydrogenation of *CHO, resulting in the non-CO pathway. Meanwhile, the *CHO/*CO intermediate generated at inner Pt-O-Ce sites can migrate to edge, inducing the subsequent coupling reaction, thus avoiding poisoning while promoting reaction efficiency. Consequently, Pt ALs/CeO2 exhibits exceptionally catalytic stability with negligible degradation even under 1000 s pure CO poisoning operation and high mass activity (14.87 A/mgPt), enabling it one of the best-performing alkali-stable MOR catalysts.

An enhanced nonparametric quality control chart with application related to industrial process.

In various practical situations, the information about the process distribution is sometimes partially or completely unavailable. In these instances, practitioners prefer to use nonparametric charts as they don't restrict the assumption of normality or specific distribution. In this current article, a nonparametric double homogeneously weighted moving average control chart based on the Wilcoxon signed-rank statistic is developed for monitoring the location parameter of the process. The run-length profiles of the newly developed chart are obtained by using Monte Carlo simulations. Comparisons are made based on various performance metrics of run-length distribution among proposed and existing nonparametric counterparts charts. The extra quadratic loss is used to evaluate the overall performance of the proposed and existing charts. The newly developed scheme showed comparatively better results than its existing counterparts. For practical implementation of the suggested scheme, the real-world dataset related to the inside diameter of the automobile piston rings is also used.

Potential Mechanism by which Eriodictyol Protects against Doxorubicininduced Cardiotoxicity based on Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation.

BACKGROUND: The clinical use of doxorubicin (DOX), an anthracycline antibiotic with broad-spectrum applications against various malignant tumors, is limited by doxorubicininduced cardiotoxicity (DIC). Eriodictyol (ERD) has shown cardioprotective effects, but the mechanism of its protective effect on DIC remains unknown. AIMS: This study aimed to explore the potential mechanisms by which ERD confers protection against DIC. METHODS: ERD and DIC targets were identified from the TCMSP, PharmMaper, SwissTargetPrediction, TargetNet, BATMAN, GeneCards, and PharmGKB databases. Differential gene expression data between DIC and normal tissues were extracted from the GEO database. A protein‒ protein interaction (PPI) network of the intersecting ERD-DIC targets was constructed using the STRING platform and visualized with Cytoscape 3.10.0 software. Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for ERD-DIC cross-targets were conducted. Validation included molecular docking with AutoDock Tools software and molecular dynamics simulations with Gromacs 2019.6 software. RESULTS: Network pharmacology analysis revealed 43 intersecting ERD-DIC targets, including 6 key targets. GO functional enrichment analysis indicated that the intersecting targets were enriched in 550 biological processes, 45 cell components, and 41 molecular functions. KEGG pathway enrichment analysis identified 114 enriched signaling pathways. Molecular docking revealed a strong binding affinity between ERD and 6 key targets, as well as multiple targets within the ROS pathway. Molecular dynamics simulations indicated that ERD has favorable binding with 3 crucial targets. CONCLUSION: The systematic network pharmacology analysis suggests that ERD may mitigate DIC through multiple targets and pathways, with the ROS pathway potentially playing a crucial role. These findings provide a reference for foundational research and clinical applications of ERD in treating DIC.

Fluorescence Sensing Properties of a Bibranched Cyanostilbene Derivative Containing -NH2 for Trace Water and Picric Acid Determination.

In order to design organic small molecule fluorescent materials with multiple sensing, a bibranched -NH2 modified cyanostilbene derivative (AM) was synthesized. It exhibits solvent and aggregation-induced emission effects, with a solid-state quantum yield of 28%, which is seven times higher than that in THF. The synthesized sample AM demonstrated high sensitivity to trace water via a fluorescence "turn-off" response, achieving a low detection limit of 0.41 µM in THF and 0.80 µM in EtOH. AM also exhibits a "turn-off" response to picric acid, attributed to the photo-induced electron transfer effect it induces. The recognition of picric acid by AM demonstrates specificity and resistance to interference from nitro explosives, with a detection limit of 300 ppb and a linear relationship (R2 = 0.9981) at the range of 0-4 equivalents AM. Such acid recognition can facilitate the design of qualitative test papers and safety inks. Additionally, AM can function as a temperature sensor with a linear relationship (R2 = 0.9976) within the temperature range of 25-110 °C. Leveraging these unique characteristics, a series of methods were proposed for the direct quantitative determination of trace water in nonaqueous solvents, picric acid, and temperature.

Novel Metal-Free Synthesis of 3-Substituted Isocoumarins and Evaluation of Their Fluorescence Properties for Potential Applications.

A novel metal-free synthesis of 3-substituted isocoumarins through a sequential O-acylation/Wittig reaction has been established. The readily accessible (2-carboxybenzyl)-triphenylphosphonium bromide and diverse chlorides produced various 1H-isochromen-1-one in the presence of triethylamine, employing sequential O-acylation and an intramolecular Wittig reaction of acid anhydride. Reactions using these facile conditions have exhibited high functional group tolerance and excellent yields (up to 90%). Moreover, the fluorescence properties of isocoumarin derivatives were evaluated at the theoretical and experimental levels to determine their potential application in fluorescent materials. These derivatives have good photoluminescence in THF with a large Stokes shift and an absolute fluorescence quantum yield of up to 14%.