Machine Learning-Based Prediction of Intraoperative Red Blood Cell Transfusion in Aortic Valve Replacement Surgery.

BACKGROUND: Blood shortage is a global challenge, impacting elective surgeries with high bleeding risk. Predicting intraoperative blood use, optimizing resource allocation, and ensuring safe elective surgery are vital. This study targets identifying key bleeding risk factors in Aortic Valve Replacement (AVR) through machine learning. METHODS: Data from 702 AVR patients were split into 70% training and 30% test sets. Thirteen models predicted RBC transfusion. SHapley Additive exPlanations (SHAP) analyzed risk factors. RESULTS: Logistic Regression excelled, with Area Under Curve (AUC) 0.872 and 81.0% accuracy on the test set. Notably, female gender, Hemoglobin (HGB) < 131.91 g/L, Hematocrit (HCT) < 0.41L/L, weight < 59.49 kg, age > 54.47 year, Mean Corpuscular Hemoglobin (MCH) < 29.15 pg, Total Protein (TP) > 69.7 g/L, FIB > 2.61 g/L, height < 160 cm, and type of operation is Surgical Aortic Valve Replacement (SAVR) were significant RBC transfusion predictors. CONCLUSIONS: The study's model accurately forecasts AVR-related RBC transfusions. This informs presurgery blood preparations, reducing resource waste and aiding clinicians in optimizing patient care.

Influence of implant distribution on the biomechanical behaviors of mandibular implant-retained overdentures: a three-dimensional finite element analysis.

OBJECTIVE: To assess stress distribution in peri-implant bone and attachments of mandibular overdentures retained by small diameter implants, and to explore the impact of implant distribution on denture stability. METHODS: Through three-dimensional Finite Element Analysis (3D FEA), four models were established: three models of a two mandibular implants retained overdenture (IOD) and one model of a conventional complete denture (CD). The three IOD models consisted of one with two implants in the bilateral canine area, another with implants in the bilateral lateral incisor area, and the third with one implant in the canine area, and another in the lateral incisor area. Three types of loads were applied on the overdenture for each model: a 100 N vertical load and a inclined load on the left first molar, and a100N vertical load on the lower incisors. The stress distribution in the peri-implant bone, attachments, and the biomechanical behaviors of the overdentures were analyzed. RESULTS: Despite different distribution of implants, the maximum stress values in peri-implant bone remained within the physiological threshold for all models across three loading conditions. The dispersed implant distribution design (implant in the canine area) exhibited the highest maximum stress in peri-implant bone (822.8 µe) and the attachments (275 MPa) among the three IOD models. The CD model demonstrated highest peak pressure on mucosa under three loading conditions (0.8188 Mpa). The contact area between the denture and mucosa of the CD model was smaller than that in the IOD models under molar loading, yet it was larger in the CD model compared to the IOD model under anterior loading. However, the contact area between the denture and mucosa under anterior loading in all models was significantly smaller than those under molar loading. The IOD in all three models exhibited significantly less rotational movement than the complete denture. Different implant positions had minimal impact on the rotational movement of the IOD. CONCLUSION: IOD with implants in canine area exhibited the highest maximum stress in the peri-implant bone and attachments, and demonstrated increased rotational movement. The maximum principal stress was concentrated around the neck of the small diameter one-piece implant, rather than in the abutment. An overdenture retained by two implants showed better stability than a complete denture.

Discovery of a novel series of pyridone amides as NaV1.8 inhibitors.

The NaV1.8 channel, mainly found in the peripheral nervous system, is recognized as one of the key factors in chronic pain. The molecule VX-150 was initially promising in targeting this channel, but the phase II trials of VX-150 did not show expected pain relief results. By analyzing the interaction mode of VX-150 and NaV1.8, we developed two series with a total of 19 molecules and examined their binding affinity to NaV1.8 in vitro and analgesic effect in vivo. One compound, named 2j, stood out with notable activity against the NaV1.8 channel and showed effective pain relief in models of chronic inflammatory pain and neuropathic pain. Our research points to 2j as a strong contender for developing safer pain-relief treatments.

An Integrated Clinical and Computerized Tomography-Based Radiomic Feature Model to Separate Benign from Malignant Pleural Effusion.

INTRODUCTION: Distinguishing between malignant pleural effusion (MPE) and benign pleural effusion (BPE) poses a challenge in clinical practice. We aimed to construct and validate a combined model integrating radiomic features and clinical factors using computerized tomography (CT) images to differentiate between MPE and BPE. METHODS: A retrospective inclusion of 315 patients with pleural effusion (PE) was conducted in this study (training cohort: n = 220; test cohort: n = 95). Radiomic features were extracted from CT images, and the dimensionality reduction and selection processes were carried out to obtain the optimal radiomic features. Logistic regression (LR), support vector machine (SVM), and random forest were employed to construct radiomic models. LR analyses were utilized to identify independent clinical risk factors to develop a clinical model. The combined model was created by integrating the optimal radiomic features with the independent clinical predictive factors. The discriminative ability of each model was assessed by receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA). RESULTS: Out of the total 1,834 radiomic features extracted, 15 optimal radiomic features explicitly related to MPE were picked to develop the radiomic model. Among the radiomic models, the SVM model demonstrated the highest predictive performance [area under the curve (AUC), training cohort: 0.876, test cohort: 0.774]. Six clinically independent predictive factors, including age, effusion laterality, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 125 (CA125), and neuron-specific enolase (NSE), were selected for constructing the clinical model. The combined model (AUC: 0.932, 0.870) exhibited superior discriminative performance in the training and test cohorts compared to the clinical model (AUC: 0.850, 0.820) and the radiomic model (AUC: 0.876, 0.774). The calibration curves and DCA further confirmed the practicality of the combined model. CONCLUSION: This study presented the development and validation of a combined model for distinguishing MPE and BPE. The combined model was a powerful tool for assisting in the clinical diagnosis of PE patients.

Nanozyme-based Clusterphene for Enhanced Electrically Catalytic Cancer Therapy.

Nanozyme mediated catalytic therapy is an attractive strategy for cancer therapy. However, the nanozymes are tended to assemble into 3D architectures, resulting in poor catalytic efficiency for therapy. This study designs the assembly of nanozymes and natural enzymes into the layered structures featuring hexagonal pores as nanozyme clusterphene and investigates their catalytic therapy with the assistance of electric field. The nanozyme-based clusterphene consists of polyoxometalate (POM) and natural glucose oxidase (GOx), named POMG-based clusterphene, which facilitate multi-enzyme activities including peroxidase (POD), catalase (CAT), and glutathione oxidase (GPx). The highly ordered layers with hexagonal pores of POMG units significantly improve the peroxidase-like (POD-like) activity of the nanozyme and thus the sustained production of reactive oxygen species (ROS). At the same time, GOx can increase endogenous H2O2 and produce gluconic acid while consuming glucose, the nutrient of tumor cell growth. The results indicate that the POD-like activity of POMG-based clusterphene increase approximately sevenfold under electrical stimulation compared with Nd-substituted keggin type POM cluster (NdPW11). The experiments both in vitro and in vivo show that the proposed POMG-based clusterphene mediated cascade catalytic therapy is capable of efficient tumor inhibiting and preventing tumor proliferation in tumor-bearing mice model, promising as an excellent candidate for catalytic therapy.

Development of the Readiness for Hospital Discharge Scale for Patients with Bile Duct Carcinoma Catheterized After Percutaneous Transhepatic Cholangial Drainage: A Validity and Reliability Study.

Objective: We develop the Readiness for Hospital Discharge Scale (RHDS) for patients with bile duct carcinoma catheterized after percutaneous transhepatic cholangial drainage (PTCD) and test the reliability and validity of the scale, so as to provide a quantitative tool for evaluating the discharge readiness of patients catheterized after PTCD. Methods: The initial scale was developed following literature review, qualitative interviews, expert consultation, and other methods based on Meleis' Theory of Transition. We selected a total of 286 patients with bile duct carcinoma catheterized after PTCD from four tertiary A-grade hospitals in Nantong City. We conducted a cross-sectional survey using the initial scale to test the validity and reliability of the scale. Results: RHDS for patients catheterized post-PTCD consisted of five dimensions, with a cumulative variance contribution rate of 74.6%. The Cronbach's α coefficient of the scale was 0.856, and that of each dimension was between 0.740 and 0.891; the scale-content validity index (S-CVI) was 0.875. Conclusion: RHDS for patients with bile duct carcinoma catheterized after PTCD developed in this study, has good reliability and validity, and can be a useful tool for evaluating the discharge readiness of patients with bile duct carcinoma catheterized after PTCD.

Strategies to Reverse Hypoxic Tumor Microenvironment for Enhanced Sonodynamic Therapy.

Sonodynamic therapy (SDT) has emerged as a highly effective modality for the treatment of malignant tumors owing to its powerful penetration ability, noninvasiveness, site-confined irradiation, and excellent therapeutic efficacy. However, the traditional SDT, which relies on oxygen availability, often fails to generate a satisfactory level of reactive oxygen species because of the widespread issue of hypoxia in the tumor microenvironment of solid tumors. To address this challenge, various approaches are developed to alleviate hypoxia and improve the efficiency of SDT. These strategies aim to either increase oxygen supply or prevent hypoxia exacerbation, thereby enhancing the effectiveness of SDT. In view of this, the current review provides an overview of these strategies and their underlying principles, focusing on the circulation of oxygen from consumption to external supply. The detailed research examples conducted using these strategies in combination with SDT are also discussed. Additionally, this review highlights the future prospects and challenges of the hypoxia-alleviated SDT, along with the key considerations for future clinical applications. These considerations include the development of efficient oxygen delivery systems, the accurate methods for hypoxia detection, and the exploration of combination therapies to optimize SDT outcomes.

Co-based Nanozymatic Profiling: Advances Spanning Chemistry, Biomedical, and Environmental Sciences.

Nanozymes, next-generation enzyme-mimicking nanomaterials, have entered an era of rational design; among them, Co-based nanozymes have emerged as captivating players over times. Co-based nanozymes have been developed and have garnered significant attention over the past five years. Their extraordinary properties, including regulatable enzymatic activity, stability, and multifunctionality stemming from magnetic properties, photothermal conversion effects, cavitation effects, and relaxation efficiency, have made Co-based nanozymes a rising star. This review presents the first comprehensive profiling of the Co-based nanozymes in the chemistry, biology, and environmental sciences. The review begins by scrutinizing the various synthetic methods employed for Co-based nanozyme fabrication, such as template and sol-gel methods, highlighting their distinctive merits from a chemical standpoint. Furthermore, a detailed exploration of their wide-ranging applications in biosensing and biomedical therapeutics, as well as their contributions to environmental monitoring and remediation is provided. Notably, drawing inspiration from state-of-the-art techniques such as omics, a comprehensive analysis of Co-based nanozymes is undertaken, employing analogous statistical methodologies to provide valuable guidance. To conclude, a comprehensive outlook on the challenges and prospects for Co-based nanozymes is presented, spanning from microscopic physicochemical mechanisms to macroscopic clinical translational applications.

Polyoxometalate-Nanozyme-Integrated Nanomotors (POMotors) for Self-Propulsion-Promoted Synergistic Photothermal-Catalytic Tumor Therapy.

Enzyme-powered nanomotors have demonstrated promising potential in biomedical applications, especially for catalytic tumor therapy, owing to their ability of self-propulsion and bio-catalysis. However, the fragility of natural enzymes limits their environmental adaptability and also therapeutic efficacy in catalysis-enabled tumor therapy. Herein, polyoxometalate-nanozyme-based light-driven nanomotors were designed and synthesized for targeted synergistic photothermal-catalytic tumor therapy. In this construct, the peroxidase-like activity of the P2 W18 Fe4 polyoxometalates-based nanomotors can provide self-propulsion and facilitate their production of reactive oxygen species thus killing tumor cells, even in the weakly acidic tumor microenvironment. Conjugated polydopamine endows the nanomotors with the capability of light-driven self-propulsion behavior. After 10 min of NIR (808 nm) irradiation, along with the help of epidermal growth factor receptor antibody, the targeted accumulation and penetration of nanomotors in the tumor enabled highly efficient synergistic photothermal-catalytic therapy. This approach overcomes the disadvantages of the intrinsically fragile nature of enzyme-powered nanomotors in physiological environments and, more importantly, provides a motility-behavior promoted synergistic anti-tumor strategy.

A computer-aided determining method for the myometrial infiltration depth of early endometrial cancer on MRI images.

To classify early endometrial cancer (EC) on sagittal T2-weighted images (T2WI) by determining the depth of myometrial infiltration (MI) using a computer-aided diagnosis (CAD) method based on a multi-stage deep learning (DL) model. This study retrospectively investigated 154 patients with pathologically proven early EC at the institution between January 1, 2018, and December 31, 2020. Of these patients, 75 were in the International Federation of Gynecology and Obstetrics (FIGO) stage IA and 79 were in FIGO stage IB. An SSD-based detection model and an Attention U-net-based segmentation model were trained to select, crop, and segment magnetic resonance imaging (MRl) images. Then, an ellipse fitting algorithm was used to generate a uterine cavity line (UCL) to obtain MI depth for classification. In the independent test datasets, the uterus and tumor detection model achieves an average precision rate of 98.70% and 87.93%, respectively. Selecting the optimal MRI slices method yields an accuracy of 97.83%. The uterus and tumor segmentation model with mean IOU of 0.738 and 0.655, mean PA of 0.867 and 0.749, and mean DSC of 0.845 and 0.779, respectively. Finally, the CAD method based on the calculated MI depth reaches an accuracy of 86.9%, a sensitivity of 81.8%, and a specificity of 91.7% for early EC classification. In this study, the CAD method implements an end-to-end early EC classification and is found to be on par with radiologists in terms of performance. It is more intuitive and interpretable than previous DL-based CAD methods.

Risk factors and predictive models for early recurrent intussusception in children: a retrospective cohort study.

Background: Early recurrent intussusception (ERI) in children is common and seriously affects the physical and mental health of the children. There are few reports discussing risk factors for ERI in children, and this study aims to identify risk factors for ERI in children and build predictive models. Methods: We conducted a retrospective study of 787 children with no relapse intussusception (NRI) and 82 children with ERI between January 2011 and December 2021. Univariate and multifactorial stepwise logistic regression analysis was used to analyze the correlation between 11 factors and ERI, to determine the independent risk factors for ERI in children. The prediction model was established by independent risk factors and then verified. Results: Age, vomiting, bloody stools, and monocyte ratios were independently correlated with the composite endpoint (P<0.05). A nomogram was constructed and a calibration curve was plotted, using independent risk factors. Based on the disease's diagnostic score, the predictive model's performance was validated by using logistic regression receiver operating characteristic (ROC) curve detection, with area under the curve (AUC) value of 0.883 [95% confidence interval (CI): 0.846-0.920], and the calibration curve was close to the ideal diagonal line. In addition, the decision curve analysis (DCA) showed that the model had significant net benefits. Conclusions: Independent risk factors for ERI in children are age, vomiting, bloody stool, and monocyte ratio. Children older than 1 year in age, who lacked vomiting and bloody stool symptoms, and who exhibited an elevated ratio of monocytes were more likely to relapse early. The predictive model constructed herein can predict the early recurrence of children with ERI, providing a reference for clinicians' individualized judgments.

Titanium-catalyzed highly stereoselective anti-Markovnikov intermolecular hydroalkoxylation of alkynes to prepare Z-enol ethers.

Enol ethers are essential synthetic frameworks and widely applied in organic synthesis; however, high regio- and stereo-selective access to enol ethers remains challenging. Herein, we report a titanium-catalyzed stereospecific anti-Markovnikov hydroalkoxylation reaction of alkynes for the synthesis of Z-enol ethers with excellent functional group tolerance and yields. Mechanistic studies showed that the titanium coordinates with the alkyne and then an oxygen anion attacks the π-bond of the alkyne from the backside to provide a trans-oxygen metallation intermediate, which accounts for the high Z-stereoselectivity. Furthermore, Z-enol ethers could be applied as a kind of synthon for late-stage transformations and gram-scale synthesis, which demonstrates their potential value in organic synthesis.

A Novel Bifunctional µOR Agonist and σ1R Antagonist with Potent Analgesic Responses and Reduced Adverse Effects.

Bifunctional ligands possessing both µOR agonism and σ1R antagonism have shown promise in producing strong analgesic effects with reduced opioid-related side effects. However, the µOR agonism activity of most dual ligands diminishes compared with classical opioids, raising concern about their effectiveness in managing nociceptive pain. In this study, a new class of dual µOR agonist/σ1R antagonist was reported. Through structure-activity relationship analyses, we identified the optimal compound, 4x, which displayed picomolar µOR agonism activity (EC50: 0.6 ± 0.2 nM) and good σ1R inhibitory activity (Ki: 363.7 ± 5.6 nM) with excellent selectivity. Compound 4x exhibited robust analgesic effects in various pain models, with significantly reduced side effects. Importantly, compound 4x also possessed good safety profiles and no abnormalities were observed in biological parameters even under a high dosage. Our findings suggest that 4x may be a promising lead compound for developing safer opioids and warrants further in-depth studies.

One-Year Survival for Developing Acute Kidney Injury in Adult Patients with AMI Cardiogenic Shock Receiving Venoarterial Extracorporeal Membrane Oxygenation.

Objective: The incidence of cardiogenic shock cases treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support has been on the rise. Acute kidney injury (AKI) is a significant complication of cardiogenic shock and a frequent serious complication in patients requiring ECMO-supported therapy. AKI is strongly associated with unfavorable patient prognosis. However, there is a paucity of data on the influence of AKI on the prognosis of patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) who are receiving ECMO support, particularly with regard to long-term outcomes. Methods: This retrospective observational study included 103 patients in the People's Hospital of Guangxi Zhuang Autonomous Region from January 2017 and June 2022. AKI was defined according to Kidney Disease Improving Global Outcome (KDIGO) criteria. Cox regression and logistic regression were used to identify risk factors. Results: In this study, the incidence of AKI was 63.11%, with AKI stage 1, 2, and 3 accounting for 21.36%, 12.62%, and 29.13%, respectively. Patients with severe AKI had significantly higher in-hospital mortality (43.33% vs 27.40%, P < 0.001), 30-day mortality (60.00% vs 31.51%, P = 0.001), and 1-year mortality (63.67% vs 34.25%, P<0.001) than those without severe AKI. Furthermore, severe AKI significantly increased the risk of one-year mortality (HR 10.816, CI 3.118-37.512, P<0.001). Baseline serum creatinine, baseline platelet, and active cardiopulmonary resuscitation were independent predictors of one-year mortality. In addition, baseline white blood cell count, baseline aspartate aminotransferase, baseline alanine aminotransferase (ALT), baseline serum creatinine, preoperative lactate, and postoperative mean arterial pressure were independent risk factors of severe AKI during hospitalization. Conclusion: In patients with AMI-CS receiving ECMO support, AKI is highly prevalent. Development of severe AKI significantly increased the risk of one-year mortality.

Influence of Benzothiadiazole on the Accumulation and Metabolism of C6 Compounds in Cabernet Gernischt Grapes (Vitis vinifera L.).

Pre-harvest application of elicitors improves grape quality, specifically the phenolic compounds and color characteristics. Limited research has been conducted on the impact of elicitors on the C6 compounds found in grapes. This is due to lack of comprehensive studies examining the combined effects of bound aroma compounds, enzyme activity, and substrate availability. This study aimed to assess the impact of benzothiadiazole (BTH) on the physicochemical properties and C6 compounds of Cabernet Gernischt grapes during ripening. Compared with the control group (CK), BTH treatment significantly increased the 100-berry weight, skin/berry ratio, pH, total phenolic content, and total flavonoid content in ripe grapes. Additionally, BTH treatment led to significant reductions in reducing sugar, total soluble solids, titratable acidity, linoleic acid, linolenic acid, and free C6 aldehydes. Furthermore, BTH treatment significantly decreased the contents of free C6 alcohols and increased the levels of free and bound C6 esters. BTH treatment also increased the activities of lipoxygenase, alcohol dehydrogenase, and alcohol acetyltransferase enzymes, while it decreased the activity of hydroperoxide lyase enzyme. The application of BTH resulted in changes to the physicochemical properties and levels of C6 compounds in Cabernet Gernischt grapes by up-regulating enzyme activity and down-regulating precursors.

A Conjugated Microporous Polymer/Wood Aerogel with Physical Adsorption, Chemical Degradation and Antibacterial Self-Cleaning Triple Sewage Treatment Functions.

Conjugated microporous polymers (CMPs) have important applications in the fields of optoelectronics and sewage treatment due to their high specific surface area, broad visible absorption, processability and simple synthesis process. Biocompatibility, recycling, mass production and solar photodegradation are particularly important in wastewater treatment. Here, A CMP with a high specific surface area and a hierarchical pore structure (CPOP) was constructed based on 4,4',4″-Tris(carbazol-9-yl)-triphenylamine (3CZ-TPA). Furthermore, a CMP-loaded wood aerogel (CPOP/wood aerogel) with physical adsorption, chemical degradation, bacterial inhibition and self-cleaning properties was prepared by in situ polymerization and used for wastewater treatment. The obtained CPOP/wood aerogel is highly biocompatible and easy to recycle. In addition, the inherent broad visible light absorption property of CPOP endows it with promising photocatalytic properties. Subsequently, we investigated the photocatalytic mechanism of CPOP, and the results showed that it was mainly affected by peroxyl radicals, which implied and confirmed its microbial self-cleaning for secondary cleaning of water pollutants. The reported studies on CPOP/wood aerogel provide a new direction for water purification materials with excellent adsorption, degradation and antibacterial properties.

Hyperbaric oxygen improves cerebral ischemia-reperfusion injury in rats via inhibition of ferroptosis.

BACKGROUND: Our previous study found that hyperbaric oxygen (HBO) attenuated cognitive impairment in mice induced by cerebral ischemia-reperfusion injury (CIRI). However, its mechanism of action is not fully understood. In this study, we aimed to establish a rat model of cerebral ischemia-reperfusion, explore the possible role of ferroptosis in the pathogenesis of CIRI, and observe the effect of HBO on ferroptosis-mediated CIRI. METHODS: Sprague Dawley (SD) rats were randomly divided into control, model, Ferrostatin-1 (Fer-1), HBO and Fer-1+ HBO groups. Morris water maze, myelin basic protein (MBP) and ß-tubulin immunoreactivity were assessed to evaluate the neuroprotective effects of HBO on cerebral ischemia reperfusion injury. Ferroptosis were examined to investigate the mechanism underlying the effects of HBO. RESULTS: Our result showed that Fer-1 and HBO improved learning and memory ability in the navigation trail and probe trail of the Morris water maze and increased MBP and ß-tubulin immunoreactivity of the cortex in the model rats. The levels of ferritin, malondialdehyde (MDA) and glutathione (GSH) in the serum were also reversed by Fer-1 and HBO treatment. Mitochondrial cristae dissolution and vacuolization were observed in the model group by transmission electron microscopy and these conditions were improved in the Fer-1 and HBO groups. Furthermore, Fer-1 and HBO treatment reversed Prostaglandin-Endoperoxide Synthase 2 (PTGS2), Iron Responsive Element Binding Protein 2 (IREB2), acyl-CoA synthetase long chain family member 4 (ACSL4) and Solute Carrier Family 7 Member 11 (SLC7A11) mRNA levels and Transferrin Receptor 1 (TFR1), ferritin light chain (FTL), ferritin heavy chain 1 (FTH1), glutathione peroxidase 4 (GPX4), Nuclear factor E2-related factor 2 (Nrf2), lysophosphatidylcholine acyltransferase 3 (LPCAT3), c-Jun N-terminal kinase (JNK), phosphorylated c-Jun N-terminal kinase (P-JNK) phosphorylated Extracellular signal-regulated protein kinase (P-ERK) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) protein levels. The above changes were more pronounced in Fer-1+ HBOGroup. DISCUSSION: The results of the present study indicated that HBO improves cerebral ischemia-reperfusion injury in rats, which may be related to inhibition of ferroptosis. This also means that ferroptosis may become a new target of HBO against CIRI.

Multiomics analyses reveal dose-dependent effects of dicofol exposure on host metabolic homeostasis and the gut microbiota in mice.

BACKGROUND: Environmental exposure to dicofol (DCF), one of common organochlorine pesticides (OCPs) widely used for controlling agricultural pests, elicits a potential risk for human health due to its toxicity. However, potential physiological hazards of oral DCF exposure remain largely unknown. METHODS: Mice were exposed to relatively chronic and subacute DCF at different doses (5, 20 and 100 mg/kg) by gavage for 2 weeks. 1H NMR-based metabolomics was used to explore alterations of metabolic profiling induced by DCF exposure. Targeted metabolomics was subsequently employed to investigate the dose-dependent effects of oral DCF exposure on lipid metabolism and the gut microbiota-derived metabolites of mice. 16S rRNA gene sequencing was further employed to evaluate the changes of gut community of mice exposed to DCF. RESULTS: Oral exposure to DCF dose-dependently induced liver injury, manifested by hepatic lipogenesis, inflammation and liver dysfunction of mice. Typically, DCF exposure disrupted host fatty acids metabolism that were confirmed by marked alteration in the levels of related genes. DCF exposure also dose-dependently caused dysbiosis of the gut bacteria and its metabolites including altered microbial composition accompanied by inhibition of bacterial fermentation. CONCLUSION: These results provide metabolic evidence that DCF exposure dose-dependently induces liver lipidosis and disruption of the gut microbiota in mice, which enrich our views of molecular mechanism of DCF hepatoxicity.

CuI-catalyzed synthesis of multisubstituted pyrido[1,2-a]pyrimidin-4-ones through tandem Ullmann-type C-N cross-coupling and intramolecular amidation reaction.

Various multi-substituted pyrido[1,2-a]pyrimidin-4-ones were synthesized via a one-pot tandem CuI-catalyzed C-N bond formation/intramolecular amidation reaction at 130 °C in DMF. This protocol features simple operation, broad substrate scope, good functional group tolerance and gram scale preparation, thus allowing practical and modular synthesis of pyrido[1,2-a]pyrimidin-4-ones from readily available 2-halopyridine and (Z)-3-amino-3-arylacrylate ester in good to excellent yields.