Submersible voltammetric sensing probe for rapid and extended remote monitoring of opioids in community water systems.

The intensifying global opioid crisis, majorly attributed to fentanyl (FT) and its analogs, has necessitated the development of rapid and ultrasensitive remote/on-site FT sensing modalities. However, current approaches for tracking FT exposure through wastewater-based epidemiology (WBE) are unadaptable, time-consuming, and require trained professionals. Toward developing an extended in situ wastewater opioid monitoring system, we have developed a screen-printed electrochemical FT sensor and integrated it with a customized submersible remote sensing probe. The sensor composition and design have been optimized to address the challenges for extended in situ FT monitoring. Specifically, ZIF-8 metal-organic framework (MOF)-derived mesoporous carbon (MPC) nanoparticles (NPs) are incorporated in the screen-printed carbon electrode (SPCE) transducer to improve FT accumulation and its electrocatalytic oxidation. A rapid (10 s) and sensitive square wave voltammetric (SWV) FT detection down to 9.9 µgL-1 is thus achieved in aqueous buffer solution. A protective mixed-matrix membrane (MMM) has been optimized as the anti-fouling sensor coating to mitigate electrode passivation by FT oxidation products and enable long-term, intermittent FT monitoring. The unique MMM, comprising an insulating polyvinyl chloride (PVC) matrix and carboxyl-functionalized multi-walled carbon nanotubes (CNT-COOH) as semiconductive fillers, yielded highly stable FT sensor operation (> 95% normalized response) up to 10 h in domestic wastewater, and up to 4 h in untreated river water. This sensing platform enables wireless data acquisition on a smartphone via Bluetooth. Such effective remote operation of submersible opioid sensing probes could enable stricter surveillance of community water systems toward timely alerts, countermeasures, and legal enforcement.

Memory-Augmented 3D Point Cloud Semantic Segmentation Network for Intelligent Mining Shovels.

The semantic segmentation of the 3D operating environment represents the key to intelligent mining shovels' autonomous digging and loading operation. However, the complexity of the operating environment of intelligent mining shovels presents challenges, including the variety of scene targets and the uneven number of samples. This results in low accuracy of 3D semantic segmentation and reduces the autonomous operation accuracy of the intelligent mine shovels. To solve these issues, this paper proposes a 3D point cloud semantic segmentation network based on memory enhancement and lightweight attention mechanisms. This model addresses the challenges of an uneven number of sampled scene targets, insufficient extraction of key features to reduce the semantic segmentation accuracy, and an insufficient lightweight level of the model to reduce deployment capability. Firstly, we investigate the memory enhancement learning mechanism, establishing a memory module for key semantic features of the targets. Furthermore, we address the issue of forgetting non-dominant target point cloud features caused by the unbalanced number of samples and enhance the semantic segmentation accuracy. Subsequently, the channel attention mechanism is studied. An attention module based on the statistical characteristics of the channel is established. The adequacy of the expression of the key features is improved by adjusting the weights of the features. This is done in order to improve the accuracy of semantic segmentation further. Finally, the lightweight mechanism is studied by adopting the deep separable convolution instead of conventional convolution to reduce the number of model parameters. Experiments demonstrate that the proposed method can improve the accuracy of semantic segmentation in the 3D scene and reduce the model's complexity. Semantic segmentation accuracy is improved by 7.15% on average compared with the experimental control methods, which contributes to the improvement of autonomous operation accuracy and safety of intelligent mining shovels.

Fusarium mycotoxins: The major food contaminants.

Mycotoxins, which are secondary metabolites produced by toxicogenic fungi, are natural food toxins that cause acute and chronic adverse reactions in humans and animals. The genus Fusarium is one of three major genera of mycotoxin-producing fungi. Trichothecenes, fumonisins, and zearalenone are the major Fusarium mycotoxins that occur worldwide. Fusarium mycotoxins have the potential to infiltrate the human food chain via contamination during crop production and food processing, eventually threatening human health. The occurrence and development of Fusarium mycotoxin contamination will change with climate change, especially with variations in temperature, precipitation, and carbon dioxide concentration. To address these challenges, researchers have built a series of effective models to forecast the occurrence of Fusarium mycotoxins and provide guidance for crop production. Fusarium mycotoxins frequently exist in food products at extremely low levels, thus necessitating the development of highly sensitive and reliable detection techniques. Numerous successful detection methods have been developed to meet the requirements of various situations, and an increasing number of methods are moving toward high-throughput features. Although Fusarium mycotoxins cannot be completely eliminated, numerous agronomic, chemical, physical, and biological methods can lower Fusarium mycotoxin contamination to safe levels during the preharvest and postharvest stages. These theoretical innovations and technological advances have the potential to facilitate the development of comprehensive strategies for effectively managing Fusarium mycotoxin contamination in the future.

In silico fragment-based discovery of CIB1-directed anti-tumor agents by FRASE-bot.

Chemical probes are an indispensable tool for translating biological discoveries into new therapies, though are increasingly difficult to identify since novel therapeutic targets are often hard-to-drug proteins. We introduce FRASE-based hit-finding robot (FRASE-bot), to expedite drug discovery for unconventional therapeutic targets. FRASE-bot mines available 3D structures of ligand-protein complexes to create a database of FRAgments in Structural Environments (FRASE). The FRASE database can be screened to identify structural environments similar to those in the target protein and seed the target structure with relevant ligand fragments. A neural network model is used to retain fragments with the highest likelihood of being native binders. The seeded fragments then inform ultra-large-scale virtual screening of commercially available compounds. We apply FRASE-bot to identify ligands for Calcium and Integrin Binding protein 1 (CIB1), a promising drug target implicated in triple negative breast cancer. FRASE-based virtual screening identifies a small-molecule CIB1 ligand (with binding confirmed in a TR-FRET assay) showing specific cell-killing activity in CIB1-dependent cancer cells, but not in CIB1-depletion-insensitive cells.

Impact of neuromuscular block on myocardial injury after non-cardiac surgery (MINS) incidence in the early postoperative stage of older patients undergoing laparoscopic colorectal cancer resection: a randomized controlled study.

BACKGROUND: Myocardial injury after non-cardiac surgery (MINS) is a common and serious complication in older patients. This study investigates the impact of neuromuscular block on the MINS incidence and other cardiovascular complications in the early postoperative stage of older patients undergoing laparoscopic colorectal cancer resection. METHODS: 70 older patients who underwent laparoscopic colorectal cancer resection were separated into the deep neuromuscular block group and moderate neuromuscular block group for 35 cases in each group (n = 1:1). The deep neuromuscular block group maintained train of four (TOF) = 0, post-tetanic count (PTC) 1-2, and the moderate neuromuscular block group maintained TOF = 1-2 during the operation. Sugammadex sodium was used at 2 mg/kg or 4 mg/kg for muscle relaxation antagonism at the end of surgery. The MINS incidence was the primary outcome and compared with Fisher's exact test. About the secondary outcomes, the postoperative pain was analyzed with Man-Whitney U test, the postoperative nausea and vomiting (PONV) and the incidence of cardiovascular complications were analyzed with Chi-square test, intraoperative mean artery pressure (MAP) and cardiac output (CO) ratio to baseline, length of stay and dosage of anesthetics were compared by two independent samples t-test. RESULTS: MINS was not observed in both groups. The highest incidence of postoperative cardiovascular complications was lower limbs deep vein thrombosis (14.3% in deep neuromuscular block group and 8.6% in moderate neuromuscular group). The numeric rating scale (NRS) score in the deep neuromuscular block group was lower than the moderate neuromuscular block group 72 h after surgery (0(1,2) vs 0(1,2), P = 0.018). The operation time in the deep neuromuscular block group was longer (356.7(107.6) vs 294.8 (80.0), min, P = 0.008), the dosage of propofol and remifentanil was less (3.4 (0.7) vs 3.8 (1.0), mg·kg-1·h-1, P = 0.043; 0.2 (0.06) vs 0.3 (0.07), µg·kg-1·min-1, P < 0.001), and the length of hospital stay was shorter than the moderate neuromuscular block group (18.4 (4.9) vs 22.0 (8.3), day, P = 0.028). The differences of other outcomes were not statistically significant. CONCLUSIONS: Maintaining different degrees of the neuromuscular block under TOF guidance did not change the MINS incidence within 7 days after surgery in older patients who underwent laparoscopic colorectal cancer resection. TRIAL REGISTRATION: The present study was registered in the Chinese Clinical Trial Registry (10/02/2021, ChiCTR2100043323).

Optimal biochar selection for cadmium pollution remediation in Chinese agricultural soils via optimized machine learning.

Biochar is effective in mitigating heavy metal pollution, and cadmium (Cd) is the primary pollutant in agricultural fields. However, traditional trial-and-error methods for determining the optimal biochar remediation efficiency are time-consuming and inefficient because of the varied soil, biochar, and Cd pollution conditions. This study employed the machine learning method to predict the Cd immobilization efficiency of biochar in soil. The predictive accuracy of the random forest (RF) model was superior to that of the other common linear and nonlinear models. Furthermore, to improve the reliability and accuracy of the RF model, it was optimized by employing a root-mean-squared-error-based trial-and-error approach. With the aid of the optimized model, the empirical categories for soil Cd immobilization efficiency were biochar properties (60.96 %) > experimental conditions (19.6 %) ≈ soil properties (19.44 %). Finally, this study identified the optimal biochar properties for enhancing agricultural soil Cd remediation in different regions of China, which was beneficial for decision-making regarding nationwide agricultural soil remediation using biochar. The immobilization effect of alkaline biochar was pronounced in acidic soils with relatively high organic matter. This study provides insights into the immobilization mechanism and an approach for biochar selection for Cd immobilization in agricultural soil.

Large-Area Transparent Antimony-Based Perovskite Glass for High-Resolution X-ray Imaging.

Nonlead low-dimensional halide perovskites attract considerable attention as X-ray scintillators. However, most scintillation screens exhibit pronounced light scattering, which detrimentally reduces the quality of X-ray imaging. Herein, we employed a simple and straightforward solvent-free melt-quenching method to fabricate a large-area zero-dimension (0D) antimony-based perovskite transparent medium, namely (C20H20P)2SbCl5 (C20H20P+ = ethyltriphenylphosphine). The transparency is due to the large steric hindrance of C20H20P+, which hinders the formation of crystals during the quenching process, thus forming a glass with low refractive index and uniform structure. This medium exhibits a high transmittance exceeding 80% in the range of 450-800 nm and shows a large Stokes shift of 245 nm, thereby minimizing light scattering, mitigating self-absorption, and enhancing the clarity of X-ray imaging. Moreover, it exhibits a high radioluminescence light yield of ∼12,535 photons MeV-1 and displays a high X-ray spatial resolution of 30 lp mm-1 owing to its high transparency. This study presents an alternative candidate for achieving high-quality X-ray detection and extends the applicability of transparent perovskite scintillators.

Development of a Longitudinal Prostate Cancer Transcriptomic and Clinical Data Linkage.

Importance: Although tissue-based gene expression testing has become widely used for prostate cancer risk stratification, its prognostic performance in the setting of clinical care is not well understood. Objective: To develop a linkage between a prostate genomic classifier (GC) and clinical data across payers and sites of care in the US. Design, Setting, and Participants: In this cohort study, clinical and transcriptomic data from clinical use of a prostate GC between 2016 and 2022 were linked with data aggregated from insurance claims, pharmacy records, and electronic health record (EHR) data. Participants were anonymously linked between datasets by deterministic methods through a deidentification engine using encrypted tokens. Algorithms were developed and refined for identifying prostate cancer diagnoses, treatment timing, and clinical outcomes using diagnosis codes, Common Procedural Terminology codes, pharmacy codes, Systematized Medical Nomenclature for Medicine clinical terms, and unstructured text in the EHR. Data analysis was performed from January 2023 to January 2024. Exposure: Diagnosis of prostate cancer. Main Outcomes and Measures: The primary outcomes were biochemical recurrence and development of prostate cancer metastases after diagnosis or radical prostatectomy (RP). The sensitivity of the linkage and identification algorithms for clinical and administrative data were calculated relative to clinical and pathological information obtained during the GC testing process as the reference standard. Results: A total of 92 976 of 95 578 (97.2%) participants who underwent prostate GC testing were successfully linked to administrative and clinical data, including 53 871 who underwent biopsy testing and 39 105 who underwent RP testing. The median (IQR) age at GC testing was 66.4 (61.0-71.0) years. The sensitivity of the EHR linkage data for prostate cancer diagnoses was 85.0% (95% CI, 84.7%-85.2%), including 80.8% (95% CI, 80.4%-81.1%) for biopsy-tested participants and 90.8% (95% CI, 90.5%-91.0%) for RP-tested participants. Year of treatment was concordant in 97.9% (95% CI, 97.7%-98.1%) of those undergoing GC testing at RP, and 86.0% (95% CI, 85.6%-86.4%) among participants undergoing biopsy testing. The sensitivity of the linkage was 48.6% (95% CI, 48.1%-49.1%) for identifying RP and 50.1% (95% CI, 49.7%-50.5%) for identifying prostate biopsy. Conclusions and Relevance: This study established a national-scale linkage of transcriptomic and longitudinal clinical data yielding high accuracy for identifying key clinical junctures, including diagnosis, treatment, and early cancer outcome. This resource can be leveraged to enhance understandings of disease biology, patterns of care, and treatment effectiveness.

Engineering cascade biocatalysis in whole cells for syringic acid bioproduction.

BACKGROUND: Syringic acid (SA) is a high-value natural compound with diverse biological activities and wide applications, commonly found in fruits, vegetables, and herbs. SA is primarily produced through chemical synthesis, nonetheless, these chemical methods have many drawbacks, such as considerable equipment requirements, harsh reaction conditions, expensive catalysts, and numerous by-products. Therefore, in this study, a novel biotransformation route for SA production was designed and developed by using engineered whole cells. RESULTS: An O-methyltransferase from Desulfuromonas acetoxidans (DesAOMT), which preferentially catalyzes a methyl transfer reaction on the meta-hydroxyl group of catechol analogues, was identified. The whole cells expressing DesAOMT can transform gallic acid (GA) into SA when S-adenosyl methionine (SAM) is used as a methyl donor. We constructed a multi-enzyme cascade reaction in Escherichia coli, containing an endogenous shikimate kinase (AroL) and a chorismate lyase (UbiC), along with a p-hydroxybenzoate hydroxylase mutant (PobA**) from Pseudomonas fluorescens, and DesAOMT; SA was biosynthesized from shikimic acid (SHA) by using whole cells catalysis. The metabolic system of chassis cells also affected the efficiency of SA biosynthesis, blocking the chorismate metabolism pathway improved SA production. When the supply of the cofactor NADPH was optimized, the titer of SA reached 133 µM (26.2 mg/L). CONCLUSION: Overall, we designed a multi-enzyme cascade in E. coli for SA biosynthesis by using resting or growing whole cells. This work identified an O-methyltransferase (DesAOMT), which can catalyze the methylation of GA to produce SA. The multi-enzyme cascade containing four enzymes expressed in an engineered E. coli for synthesizing of SA from SHA. The metabolic system of the strain and biotransformation conditions influenced catalytic efficiency. This study provides a new green route for SA biosynthesis.

Cucurbit[8]uril Mediated Supramolecular Heterodimerisation and Photoinduced [2+2] Heterocycloaddition to Generate Unexpected [2]Rotaxanes.

In contrast to the self-assembly of homosupramolecules, the self-assembly of heterosupramolecules is more challenging and significant in various fields. Herein, we design and investigate a cucurbit[8]uril-mediated heterodimerisation using an arene-fluoroarene strategy. Moreover, the resulting heteroternary complex is found to be able to undergo a photoinduced [2+2] heterocycloaddition, resulting in the formation of an unexpected [2]rotaxane structure. This work demonstrates a novel supramolecular heterodimerisation system, not only contributing to the development of photoisomerisation systems, but also enriching synthetic methodologies of mechanically interlocked molecules.

Viral Dynamics in the Tropical Pacific Ocean: A Comparison between Within and Outside a Warm Eddy.

In mesoscale eddies, the chemical properties and biological composition are different from those in the surrounding water due to their unique physical processes. The mechanism of physical-biological coupling in warm-core eddies is unclear, especially because no studies have examined the effects of environmental factors on bacteria and viruses. The purpose of the present study was to examine the influence of an anticyclonic warm eddy on the relationship between bacterial and viral abundances, as well as viral activity (viral production), at different depths. At the core of the warm eddy, the bacterial abundance (0.48 to 2.82 × 105 cells mL-1) fluctuated less than that outside the eddy (1.12 to 7.03 × 105 cells mL-1). In particular, there was a four-fold higher viral-bacterial abundance ratio (VBR) estimated within the eddy, below the layer of the deep chlorophyll maximum, than outside the eddy. An anticyclonic warm eddy with downwelling at its center may contribute to viruses being transmitted directly into the deep ocean through adsorption on particulate organic matter while sinking. Overall, our findings provide valuable insights into the interaction between bacterial and viral abundances and their ecological mechanisms within a warm eddy.

Clinical and Imaging Characteristics of Contrast-enhanced Mammography and MRI to Distinguish Microinvasive Carcinoma from Ductal Carcinoma In situ.

RATIONALE AND OBJECTIVES: The prognosis of ductal carcinoma in situ with microinvasion (DCISM) is more similar to that of small invasive ductal carcinoma (IDC) than to pure ductal carcinoma in situ (DCIS). It is particularly important to accurately distinguish between DCISM and DCIS. The present study aims to compare the clinical and imaging characteristics of contrast-enhanced mammography (CEM) and magnetic resonance imaging (MRI) between DCISM and pure DCIS, and to identify predictive factors of microinvasive carcinoma, which may contribute to a comprehensive understanding of DCISM in clinical diagnosis and support surveillance strategies, such as surgery, radiation, and other treatment decisions. MATERIALS AND METHODS: Forty-seven female patients diagnosed with DCIS were included in the study from May 2019 to August 2023. Patients were further divided into two groups based on pathological diagnosis: DCIS and DCISM. Clinical and imaging characteristics of these two groups were analyzed statistically. The independent clinical risk factors were selected using multivariate logistic regression and used to establish the logistic model [Logit(P)]. The diagnostic performance of independent predictors was assessed and compared using receiver operating characteristic (ROC) analysis and DeLong's test. RESULTS: In CEM, the maximum cross-sectional area (CSAmax), the percentage signal difference between the enhancing lesion and background in the craniocaudal and mediolateral oblique projection (%RSCC, and %RSMLO) were found to be significantly higher for DCISM compared to DCIS (p = 0.001; p < 0.001; p = 0.008). Additionally, there were noticeable statistical differences in the patterns of enhancement morphological distribution (EMD) and internal enhancement pattern (IEP) between DCIS and DCISM (p = 0.047; p = 0.008). In MRI, only CSAmax (p = 0.012) and IEP (p = 0.020) showed significant statistical differences. The multivariate regression analysis suggested that CSAmax (in CEM or MR) and %RSCC were independent predictors of DCISM (all p < 0.05). The area under the curve (AUC) of CSAmax (CEM), %RSCC (CEM), Logit(P) (CEM), and CSAmax (MR) were 0.764, 0.795, 0.842, and 0.739, respectively. There were no significant differences in DeLong's test for these values (all p > 0.10). DCISM was significantly associated with high nuclear grade, comedo type, high axillary lymph node (ALN) metastasis, and high Ki-67 positivity compared to DCIS (all p < 0.05). CONCLUSION: The tumor size (CSAmax), enhancement index (%RS), and internal enhancement pattern (IEP) were highly indicative of DCISM. DCISM tends to express more aggressive pathological features, such as high nuclear grade, comedo-type necrosis, ALN metastasis, and Ki-67 overexpression. As with MRI, CEM has the capability to help predict when DCISM is accompanying DCIS.

The aesthetic experience of general beauty and ugly-cute memes: the role of emotion.

Generally, beauty has been regarded as an outward expression of elegance and harmony, providing visual pleasure and evoking a sense of aesthetic enjoyment. However, in recent years, a phenomenon called "ugly-cute" has emerged, challenging the conventional standards of beauty by embracing a form of "ugliness" to enhance its appeal. The reasons and mechanisms behind this phenomenon remain largely unexplored so far. This study aims to investigate the role of emotions, such as pleasure, humor, and surprise, in the relationship between ugly-cute characteristics and attractiveness. The findings reveal that general beauty directly generates attractiveness by eliciting pleasurable emotions, whereas ugly-cute memes achieve attractiveness by inducing pleasurable emotions through the mediation of humor. Furthermore, while both "ugly" and "ugly-cute" memes evoke a sense of surprise, that elicited by ugly-cute memes is accompanied by a humorous response, thereby enhancing their attractiveness, whereas the "ugly" memes fail to evoke humor and lack attractiveness. Finally, we discuss the potential implications and practical value of the current research.

Efficacy and safety of enteral supplementation with high-dose vitamin D in critically ill patients with vitamin D deficiency.

BACKGROUND: Vitamin D deficiency is associated with mortality and morbidity in critically ill patients. This study investigated the safety and effectiveness of enteral high-dose vitamin D supplementation in intensive care unit (ICU) patients in Asia. METHODS: This was a multicenter, prospective, randomized-controlled study. Eligible participants with vitamin D deficiency were randomly assigned to the control or vitamin D supplementation group. In the vitamin D supplementation group, the patients received 569,600 IU vitamin D. The primary outcome was the serum 25(OH)D level on day 7. RESULTS: 41 and 20 patients were included in the vitamin D supplementation and control groups, respectively. On day 7, the serum 25(OH)D level was significantly higher in the vitamin D supplementation group compared to the control group (28.5 [IQR: 20.2-52.6] ng/mL and 13.9 [IQR: 11.6-18.8] ng/mL, p < 0.001). Only 41.5% of the patients achieved serum 25(OH)D levels higher than 30 ng/mL in the supplementation group. This increased level was sustained in the supplementation group on both day 14 and day 28. There were no significant adverse effects noted in the supplementation group. Patients who reached a serum 25(OH)D level of >30 ng/mL on day 7 had a significantly lower 30-day mortality rate than did those who did not (5.9% vs 37.5%, p < 0.05). CONCLUSIONS: In our study, less than half of the patients reached adequate vitamin D levels after the enteral administration of high-dose vitamin D. A reduction in 30-day mortality was noted in the patients who achieved adequate vitamin D levels. TRIAL REGISTRATION CLINICALTRIALS. GOV ID: NCT04292873, Registered, March 1, 2020.

Mechanical Bond Induced Enhancement and Purification of Pyrene Emission in the Solid State.

To address key concerns on solid-state pyrene-based luminescent materials, we propose a novel and efficient mechanical bond strategy. This strategy results in a transformation from ACQ to AIE effect and a remarkable enhancement of pyrene emission in the solid state. Moreover, an unusual purification of emission is also achieved. Through computational calculation and experimental characterisation, finally determined by X-ray diffraction analysis, we prove that the excellent emissions result from mechanical bond induced refinement of molecular arrangements, including reduced π-π stacking, well-ordered packing and enhanced structural stability. This work demonstrates the potential of mechanical bond in the field of organic luminescent molecules, providing a new avenue for developing high-performance organic luminescent materials.

NCCN Guidelines® Insights: Prostate Cancer, Version 3.2024.

The NCCN Guidelines for Prostate Cancer include recommendations for staging and risk assessment after a prostate cancer diagnosis and for the care of patients with localized, regional, recurrent, and metastatic disease. These NCCN Guidelines Insights summarize the panel's discussions for the 2024 update to the guidelines with regard to initial risk stratification, initial management of very-low-risk disease, and the treatment of nonmetastatic recurrence.

Synthetic cationic helical polypeptides for the stimulation of antitumour innate immune pathways in antigen-presenting cells.

Intracellular DNA sensors regulate innate immunity and can provide a bridge to adaptive immunogenicity. However, the activation of the sensors in antigen-presenting cells (APCs) by natural agonists such as double-stranded DNAs or cyclic nucleotides is impeded by poor intracellular delivery, serum stability, enzymatic degradation and rapid systemic clearance. Here we show that the hydrophobicity, electrostatic charge and secondary conformation of helical polypeptides can be optimized to stimulate innate immune pathways via endoplasmic reticulum stress in APCs. One of the three polypeptides that we engineered activated two major intracellular DNA-sensing pathways (cGAS-STING (for cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes) and Toll-like receptor 9) preferentially in APCs by promoting the release of mitochondrial DNA, which led to the efficient priming of effector T cells. In syngeneic mouse models of locally advanced and metastatic breast cancers, the polypeptides led to potent DNA-sensor-mediated antitumour responses when intravenously given as monotherapy or with immune checkpoint inhibitors. The activation of multiple innate immune pathways via engineered cationic polypeptides may offer therapeutic advantages in the generation of antitumour immune responses.

[Prediction of Ozone Pollution in Sichuan Basin Based on Random Forest Model].

To study the long-term variation in ozone (O3) pollution in Sichuan Basin,the spatiaotemporal distribution of O3 concentrations during 2017 to 2020 was analyzed using ground-level O3 concentration data and meteorological observation data from 18 cities in the basin. The dominant meteorological factors affecting the variation in O3 concentration were screened out,and a prediction model between meteorological factors and O3 concentration was constructed based on a random forest model. Finally,a prediction analysis of O3 pollution in the Sichuan Basin urban agglomeration during 2020 was carried out. The results showed that:① O3 concentrations displayed a fluctuating trend during the period from 2017 to 2020,with a downward trend in 2019 and a rebound in 2020. ② The fluctuating trend of O3 concentration was significantly influenced by relative humidity,daily maximum temperature,and sunshine hours,whereas wind speed,air pressure,and precipitation had less impact. The linear relationships between meteorological factors were different. Air pressure was negatively correlated with other meteorological factors,whereas the remaining meteorological factors had a positive correlation. ③ The goodness of fit statistics (R2) between the predicted and actual values of the O3 prediction model constructed based on random forest demonstrated a strong predictive performance and ability to accurately forecast the long-term daily variations in O3 concentration. The random forest O3 prediction model exhibited excellent stability and generalization capability. ④ The prediction analysis of O3 concentrations in 18 cities in the basin showed that the explanation rate of variables in the prediction model reached over 80% in all cities (except Ya'an),indicating that the random forest model predicted the trend of O3 concentration accurately.

Surface Charge Effects for the Hydrogen Evolution Reaction on Pt(111) Using a Modified Grand-Canonical Potential Kinetics Method.

Surface charges of catalysts have important influences on the thermodynamics and kinetics of electrochemical reactions. Herein, we develop a modified version of the grand-canonical potential kinetics (GCP-K) method based on density functional theory (DFT) calculations to explore the effect of surface charges on reaction thermodynamics and kinetics. Using the hydrogen evolution reaction (HER) on the Pt(111) surface as an example, we show how to track the change of surface charge in a reaction and how to analyze its influence on the kinetics. Grand-canonical calculations demonstrate that the optimum hydrogen adsorption energy on Pt under the standard hydrogen electrode condition (SHE) is around -0.2 eV, rather than 0 eV established under the canonical ensemble, due to the high density of surface negative charges. By separating the surface charges that can freely exchange with the external electron reservoir, we obtain a Tafel barrier that is in good agreement with the experimental result. During the Tafel reaction, the net electron inflow into the catalyst leads to a stabilization of canonical energy and a destabilization of the charge-dependent grand-canonical component. This study provides a practical method for obtaining accurate grand-canonical reaction energetics and analyzing the surface charge induced changes.