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OBJECTIVE: In the surgery-focused field of obstetrics and gynecology (OB-GYN), the development of residents' skills is paramount. This study aims to evaluate the impact of an enhanced Peyton Four-Step Teaching Model on the foundational skill training of first-year OB-GYN residents. METHODS: Utilizing a cohort study design, we assessed 116 first-year residents from the OB-GYN residency program at Shengjing Hospital of China Medical University from June 2021 to June 2023. The 57 residents beginning their training in 2022 were part of the Refined Peyton (RP) group, introduced to the RP method; the 59 residents from 2021 served as the Traditional Teaching-mode (TTM) group, receiving conventional simulation-based instruction. Teaching effectiveness was assessed by comparing theoretical knowledge and skill performance assessments, National Medical Licensing Examination (NMLE) pass rates, direct observation of procedural skills (DOPS) one year post-training, and survey feedback. RESULTS: The theoretical knowledge scores for both groups were comparable at 78.78 ± 4.08 and 78.70 ± 3.83, with no significant difference (P = 0.76). However, the experimental group demonstrated superior performance in skill operation assessments, first-time NMLE pass rates, and DOPS evaluations one year after training [(77.05 ± 5.39) vs. (84.60 ± 5.65), 100.0% (57/57) vs. 86.4% (51/59), and (75.22 ± 3.56) vs. (82.54 ± 3.43)], as well as higher teaching satisfaction scores [(4.63 ± 0.46) vs. (3.92 ± 0.62)], with all differences being statistically significant (P < 0.05). CONCLUSION: The refined Peyton Four-Step Teaching Model significantly improves the immediate acquisition and long-term retention of clinical basic skills among OB-GYN residents, enhancing both teaching efficacy and resident satisfaction.
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Competência Clínica , Ginecologia , Internato e Residência , Obstetrícia , Humanos , Obstetrícia/educação , Ginecologia/educação , Feminino , China , Avaliação Educacional , Ensino , Estudos de Coortes , Masculino , Adulto , Educação de Pós-Graduação em MedicinaRESUMO
OBJECTIVES: This study investigated the role of fibrin on neutrophil extracellular traps (NETs) formation from neutrophils and to elucidate the involvement of mitochondria in NETs formation during periodontitis. MATERIALS AND METHODS: Plasminogen-deficient (Plg-/-) mice were employed to evaluate the effects of fibrin deposition on inflammation, bone resorption, and neutrophil infiltration in periodontal tissues. In addition, in vitro tests evaluated fibrin's impact on neutrophil-driven inflammation. Mitochondrial reactive oxygen species (mtROS) levels within neutrophils were quantified utilizing flow cytometry and immunofluorescence in vitro. Furthermore, the anti-inflammatory properties of the mtROS scavenger, Mito-TEMPO, were confirmed to regulate the NET formation in vitro and in vivo. RESULTS: Plasminogen deficiency resulted in increased fibrin deposition, neutrophil infiltration, inflammatory factors concentration, and alveolar bone resorption in periodontal tissues. After neutrophils were treated by fibrin in vitro, the expression of inflammatory factors, the formation of mtROS, and NETs enriched in mitochondrial DNA (mtDNA) were upregulated, which were reversed by Mito-TEMPO in vitro. Moreover, Mito-TEMPO alleviated inflammation in Plg-/- mice. CONCLUSIONS: This study showed that fibrin deposition in gingiva induced the NET formation in Plg-/- mice, in which the DNA in NETs was from mitochondria depending on increasing mtROS.
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ETHNOPHARMACOLOGICAL RELEVANCE: Bronchitis is a respiratory disease characterized by a productive cough. Polygala tenuifolia Willd., commonly known as Yuan zhi, is a traditional Chinese herbal medicine used for relieving cough and removing phlegm. Despite its historical use, studies are lacking on the effectiveness of P. tenuifolia in treating bronchitis. Furthermore, the molecular mechanisms underlying the action of its bioactive compounds remain unknown. AIM OF THE STUDY: This study aims to identify the main bioactive compounds responsible for the effects of P. tenuifolia liquid extract (PLE) in treating bronchitis and to elucidate the associated molecular mechanisms. MATERIALS AND METHODS: The main chemical compounds in PLE were identified and determined using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The antitussive, expectorant and anti-inflammatory activities of PLE were evaluated in an ammonia-induced mouse cough model, a tracheal phenol red excretion mouse model, and a xylene-induced ear swelling mouse model, respectively. A network pharmacology analysis was conducted to investigate the associated gene targets, gene ontology, and KEGG pathways related to the main bioactives in PLE targeting bronchitis. PLE and its five bioactive compounds were assessed for their potential anti-inflammatory activities in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Western blot analysis was conducted to elucidate the associated molecular mechanisms. RESULTS: Thirty-seven compounds in PLE were identified, and twelve main compounds were further quantified in PLE using UPLC-MS/MS. PLE oral gavage administrations (0.6 and 0.12 mg/kg) for 7 days markedly reduced cough frequency, prolonged latency period of cough, reduced phlegm and inflammation in mice. The network pharmacology analysis identified 57 gene targets of PLE against bronchitis. The PI3K/AKT and MAPK signalling pathways were the top two modulated pathways. In RAW264.7 cells, PLE (12.5-50 µg/mL) significantly reduced cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α. PLE downregulated LPS-elevated protein targets in both PI3K/AKT and MAPK signaling pathways. In PLE, tenuifolin, polygalaxanthone â â â , polygalasaponin ⠩⠩⠤⠢, tenuifoliside B, and 3,6'-Disinapoyl sucrose, were identified as the top five core components responsible for treating bronchitis. These compounds were also found to modulate the protein targets in the PI3K/AKT and MAPK signalling pathways. CONCLUSIONS: This study demonstrated the potential therapeutic effects of PLE on bronchitis by reducing cough, phlegm and inflammation. The anti-inflammatory action and molecular mechanisms of the 5 main bioactive compounds in PLE were partly validated through the in vitro assays. The findings provide valuable insights into the mechanisms underlying the traditional use of PLE for bronchitis.
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Anti-Inflamatórios , Bronquite , Tosse , Farmacologia em Rede , Extratos Vegetais , Raízes de Plantas , Polygala , Espectrometria de Massas em Tandem , Animais , Polygala/química , Espectrometria de Massas em Tandem/métodos , Camundongos , Tosse/tratamento farmacológico , Células RAW 264.7 , Anti-Inflamatórios/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Masculino , Raízes de Plantas/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Bronquite/tratamento farmacológico , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/análise , Antitussígenos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Modelos Animais de Doenças , Xilenos , Amônia , Espectrometria de Massa com Cromatografia LíquidaRESUMO
BACKGROUND: Rapid Cycle Deliberate Practice (RCDP) has gained prominence in recent years as an innovative teaching method in simulation-based training for adult and pediatric emergency medical skills. However, its application in the training of forceps delivery skills among obstetrics and gynecology residents remains unexplored. This study aimed to assess the impact of RCDP in this domain. METHODS: Conducted in March 2021, this randomized controlled study involved 60 second-year obstetrics and gynecology residents undergoing standardized training. Participants were randomly assigned to the RCDP group or the traditional teaching method (TTM) group, each comprising 30 residents. The RCDP group followed the RCDP practice mode, while the TTM group adhered to conventional simulation teaching. Post-training assessment of operational proficiency was conducted immediately and after one year. Independent operational confidence and training satisfaction were evaluated through questionnaire surveys and the Satisfaction with Simulation Experience (SSE) scale. Data analysis utilized SPSS 23.0. RESULTS: The RCDP group displayed significantly higher immediate post-training forceps operation scores compared to the TTM group (92.00 [range: 90.00-94.00] vs. 88.00 [range: 86.75-92.00]; z = 3.79; p < .001). However, no significant difference emerged in forceps operation scores after one year (86.00 [range: 85.00-88.00] vs. 85.50 [range: 84.00-88.25]; z = 0.54; p = .59). The RCDP group exhibited notable performance improvement over the TTM group (z = 3.49; p < .001). Independent operation confidence showed no significant discrepancy (p > .05). Importantly, the RCDP group reported higher satisfaction scores, particularly in the Debriefing and Reflection subscale (44.00 [range: 43.00-45.00] vs. 41.00 [range: 41.50-43.00]; z = 5.24; p < .001), contributing to an overall superior SSE score (z = 4.74; p < .001). CONCLUSIONS: RCDP exhibits immediate efficacy in elevating forceps delivery skills among residents. However, sustained skill enhancement necessitates innovative approaches, while RCDP's value lies in tailored feedback and reflection for enriched medical education.
Rapid Cycle Deliberate Practice (RCDP) demonstrates immediate effectiveness in enhancing forceps delivery skills among obstetrics and gynecology residents, leading to improved immediate performance, which also increased their satisfaction with the teaching process and operational confidence.Long-term skill retention through RCDP appears limited, highlighting the importance of ongoing reinforcement to prevent skill decay and maintain proficiency.
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Ginecologia , Internato e Residência , Treinamento por Simulação , Humanos , Competência Clínica , Ginecologia/educação , Instrumentos CirúrgicosRESUMO
A novel enrofloxacin-degrading fungus was isolated from a rhizosphere sediment of the submerged macrophyte Vallisneria spiralis L.. The isolate, designated KC0924g, was identified as a member of the genus Humicola based on morphological characteristics and tandem conserved sequence analysis. The optimal temperature and pH for enrofloxacin degradation by strain KC0924g were 28 °C and 9.0, respectively. Under such condition, 98.2% of enrofloxacin with an initial concentration of 1 mg L-1 was degraded after 72 h of incubation, with nine possible degradation products identified. Four different metabolic pathways were proposed, which were initiated by cleavage of the piperazine moiety, hydroxylation of the aromatic ring, oxidative decarboxylation, or defluorination. In addition to enrofloxacin, strain KC0924g also degraded other fluoroquinolone antibiotics (ciprofloxacin, norfloxacin, and ofloxacin), malachite green (an illegal additive in aquaculture), and leucomalachite green. Pretreatment of cells of strain KC0924g with Cu2+ accelerated ENR degradation. Furthermore, it was speculated that a flavin-dependent monooxygenase was involved in ENR degradation, based on the increased transcriptional levels of these two genes after Cu2+ induction. This work enriches strain resources for enrofloxacin remediation and, more importantly, would facilitate studies on the molecular mechanism of ENR degradation with degradation-related transcriptome available.
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Intumescent flame retardants (IFRs) are mainly composed of ammonium polyphosphate (APP), melamine (ME), and some macromolecular char-forming agents. The traditional IFR still has some defects in practical application, such as poor compatibility with the matrix and low flame-retardant efficiency. In order to explore the best balance between flame retardancy and mechanical properties of flame-retardant polyformaldehyde (POM) composite, a biobased calcium magnesium bi-ionic melamine phytate (DPM) synergist was prepared based on renewable biomass polyphosphate phytic acid (PA), and its synergistic system with IFRs was applied to an intumescent flame-retardant POM system. POM/IFR systems can only pass the V-1 grade of the vertical combustion test (UL-94) if they have a limited oxygen index (LOI) of only 48.5%. When part of an IFR was replaced by DPM, the flame retardancy of the composite was significantly improved, and the POM/IFR/4 wt%DPM system reached the V-0 grade of UL-94, and the LOI reached 59.1%. Compared with pure POM, the PkHRR and THR of the POM/IFR/4 wt%DPM system decreased by 61.5% and 51.2%, respectively. Compared with the POM/IFR system, the PkHRR and THR of the POM/IFR/4 wt%DPM system were decreased by 20.8% and 27.5%, respectively, and carbon residue was increased by 37.2%. The mechanical properties of the composite also showed a continuous upward trend with the increase in DPM introduction. It is shown that the introduction of DPM not only greatly reduces the heat release rate and heat release amount of the intumescent flame-retardant POM system, reducing the fire hazard, but it also effectively improves the compatibility between the filler and the matrix and improves the mechanical properties of the composite. It provides a new approach for developing a new single-component multifunctional flame retardant or synergist for intumescent flame-retardant POM systems.
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[This corrects the article DOI: 10.3389/fonc.2022.887068.].
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The significant anatomical changes in large intestine of germ-free (GF) mice provide excellent material for understanding microbe-host crosstalk. We observed significant differences of GF mice in anatomical and physiological involving in enlarged cecum, thinned mucosal layer and enriched water in cecal content. Furthermore, integration analysis of multi-omics data revealed the associations between the structure of large intestinal mesenchymal cells and the thinning of the mucosal layer. Increased Aqp8 expression in GF mice may contribute to enhanced water secretion or altered hydrodynamics in the cecum. In addition, the proportion of epithelial cells, nutrient absorption capacity, immune function and the metabolome of cecum contents of large intestine were also significantly altered. Together, this is the first systematic study of the transcriptome and metabolome of the cecum and colon of GF mice, and these findings contribute to our understanding of the intricate interactions between microbes and the large intestine.
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To investigate whether intermittent theta burst stimulation over the cerebellum induces changes in resting-state electroencephalography microstates in patients with subacute stroke and its correlation with cognitive and emotional function. Twenty-four stroke patients and 17 healthy controls were included in this study. Patients and healthy controls were assessed at baseline, including resting-state electroencephalography and neuropsychological scales. Fifteen patients received lateral cerebellar intermittent theta burst stimulation as well as routine rehabilitation training (intermittent theta burst stimulation-RRT group), whereas 9 patients received only conventional rehabilitation training (routine rehabilitation training group). After 2 wk, baseline data were recorded again in both groups. Stroke patients exhibited reduced parameters in microstate D and increased parameters in microstate C compared with healthy controls. However, after the administration of intermittent theta burst stimulation over the lateral cerebellum, significant alterations were observed in the majority of metrics for both microstates D and C. Lateral cerebellar intermittent theta burst stimulation combined with conventional rehabilitation has a stronger tendency to improve emotional and cognitive function in patients with subacute stroke than conventional rehabilitation. The improvement of mood and cognitive function was significantly associated with microstates C and D. We identified electroencephalography microstate spatiotemporal dynamics associated with clinical improvement following a course of intermittent theta burst stimulation therapy.
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Eletroencefalografia , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/complicações , Estimulação Magnética Transcraniana , Cerebelo , CogniçãoRESUMO
The gut-liver axis is a complex bidirectional communication pathway between the intestine and the liver in which microorganisms and their metabolites flow from the intestine through the portal vein to the liver and influence liver function. In a sterile environment, the phenotype or function of the liver is altered, but few studies have investigated the specific cellular and molecular effects of microorganisms on the liver. To this end, we constructed single-cell and spatial transcriptomic (ST) profiles of germ-free (GF) and specific-pathogen-free (SPF) mouse livers. Single-cell RNA sequencing (scRNA-seq) and single-nucleus RNA sequencing (snRNA-seq) revealed that the ratio of most immune cells was altered in the liver of GF mice; in particular, natural killer T (NKT) cells, IgA plasma cells (IgAs) and Kupffer cells (KCs) were significantly reduced in GF mice. Spatial enhanced resolution omics sequencing (Stereo-seq) confirmed that microorganisms mediated the accumulation of Kupffer cells in the periportal zone. Unexpectedly, IgA plasma cells were more numerous and concentrated in the periportal vein in liver sections from SPF mice but less numerous and scattered in GF mice. ST technology also enables the precise zonation of liver lobules into eight layers and three patterns based on the gene expression level in each layer, allowing us to further investigate the effects of microbes on gene zonation patterns and functions. Furthermore, untargeted metabolism experiments of the liver revealed that the propionic acid levels were significantly lower in GF mice, and this reduction may be related to the control of genes involved in bile acid and fatty acid metabolism. In conclusion, the combination of sc/snRNA-seq, Stereo-seq, and untargeted metabolomics revealed immune system defects as well as altered bile acid and lipid metabolic processes at the single-cell and spatial levels in the livers of GF mice. This study will be of great value for understanding host-microbiota interactions.
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Nitrate and SMX both play a critical role in their biotransformation in biodegradable polymer-supported denitrification biofilters. However, the mutual influences of nitrate and SMX on their biotransformation for long-term operation remained obscure. Results showed SMX and nitrate had divergent effects on SMX removal. SMX removal rates was positively related with its loading rates, whereas they were negatively related to NLRs. The most abundant metabolite C10H14O3N3S (the reduced form of SMX moiety) from the N-O bond cleavage pathway by UHPLC-LTQ-Orbitrap-MS/MS and effluent TOC variations confirmed the presence of electron donor competition between nitrate and SMX. SMX less than 1000 µg/L had a negligible influence on denitrification performance. Denitrifiers such as Azospira and Denitratisoma were still enriched after chronic exposure, and nosZ/narG positively correlated with sul1/sul2 resistance genes, which were both responsible for the negligible influence of SMX. This work could guide the operational management of denitrification biofilters for simultaneous nitrate and antibiotics removal.
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Nitratos , Sulfametoxazol , Ácido 3-Hidroxibutírico , Desnitrificação , Espectrometria de Massas em Tandem , Biotransformação , HidroxibutiratosRESUMO
Context: Ras-associated binding 35 (RAB35) is an oncogenic, guanosine triphosphate (GTP)ase that plays a role in cancer invasion, metastasis, and immune evasion. However, systematic and comprehensive research to identify the importance of RAB35 in various cancer types is still absent. Objective: The study intended to explore the potential value of RAB35 as a molecular biomarker. Design: The research team performed a genetic evaluation of RAB35. Setting: The study took place at the Second Affiliated Hospital of Wenzhou Medical University in Wenzhou, China. Outcome Measures: The research team assessed the expression of RAB35 in various tumor tissues and performed correlation analyses between RAB35 expression and prognosis, molecular subtypes, immunological subtypes, immune-associated cell infiltration, the tumor immune microenvironment, and drug sensitivity in pan-cancer. Results: RAB35 exhibited significant differential expression for 21 cancer types. It demonstrated high sensitivity and specificity in diagnosing eight cancer types, showed distinct expression patterns in various molecular subtypes for six cancer types, and found different immune subtypes for eight cancer types. The abnormal expression of RAB35 was significantly related to overall survival (OS) for nine cancer types, progress free interval (PFI) for five cancer types, and disease-specific survival (DSS) for five cancer types. Its abnormal expression was closely associated with the immune microenvironment and multiple immune cells. Furthermore, it was related to the drug sensitivity for various drugs and might be associated with chemotherapy resistance. Conclusions: RAB35 showed significant differential expression in various cancers and was significantly related to the prognosis of cancer patients, the immune microenvironment, multiple immune cells, drug sensitivity to various drugs, and chemotherapy resistance. It may serve as a potential biomarker and therapeutic target for cancer treatment.
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Neoplasias , Humanos , Prognóstico , Neoplasias/diagnóstico , China , Biomarcadores , Microambiente Tumoral , Proteínas rab de Ligação ao GTP/genéticaRESUMO
Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (R-SNAREs) mainly promoted the assembly of the SNARE complex to drive the final membrane fusion step of membrane transport. Previous research on R-SNAREs has mainly focused on development and growth and has rarely been involved in abiotic stress, especially in cotton. Here, we performed a comprehensive analysis of R-SNARE genes in upland cotton. In total, 51 Gh-R-SNARE genes across six phylogenetic groups were unevenly distributed on 21 chromosomes. Cis elements related to plant growth and response to abiotic stress responses were found in the promoter region of Gh-R-SNAREs. Nine Gh-R-SNARE genes were obviously upregulated under drought stress conditions by RNA-seq and qRT-PCR analysis. Among them, GhVAMP72l might be the key candidate gene contributing to drought stress tolerance in cotton by virus-induced gene silencing (VIGS) assay. These results provide valuable insights for the functional analysis of cotton R-SNAREs in response to drought stress and highlight potential beneficial genes for genetic improvement and breeding in cotton.
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Gut microbes exhibit complex interactions with their hosts and shape an organism's immune system throughout its lifespan. As the largest secondary lymphoid organ, the spleen has a wide range of immunological functions. To explore the role of microbiota in regulating and shaping the spleen, we employ scRNA-seq and Stereo-seq technologies based on germ-free (GF) mice to detect differences in tissue size, anatomical structure, cell types, functions, and spatial molecular characteristics. We identify 18 cell types, 9 subtypes of T cells, and 7 subtypes of B cells. Gene differential expression analysis reveals that the absence of microorganisms results in alterations in erythropoiesis within the red pulp region and congenital immune deficiency in the white pulp region. Stereo-seq results demonstrate a clear hierarchy of immune cells in the spleen, including marginal zone (MZ) macrophages, MZ B cells, follicular B cells and T cells, distributed in a well-defined pattern from outside to inside. However, this hierarchical structure is disturbed in GF mice. Ccr7 and Cxcl13 chemokines are specifically expressed in the spatial locations of T cells and B cells, respectively. We speculate that the microbiota may mediate the structural composition or partitioning of spleen immune cells by modulating the expression levels of chemokines.
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Análise da Expressão Gênica de Célula Única , Baço , Camundongos , Animais , Baço/metabolismo , Linfócitos B , Quimiocinas/metabolismo , ImunidadeRESUMO
Drought stress is the major abiotic factor that can seriously affect plant growth and crop production. The functions of flavin-containing monooxygenases (FMOs) are known in animals. They add molecular oxygen to lipophilic compounds or produce reactive oxygen species (ROS). However, little information on FMOs in plants is available. Here, we characterized a tomato drought-responsive gene that showed homology to FMO, and it was designated as FMO1. FMO1 was downregulated promptly by drought and ABA treatments. Transgenic functional analysis indicated that RNAi suppression of the expression of FMO1 (FMO1-Ri) improved drought tolerance relative to wild-type (WT) plants, whereas overexpression of FMO1 (FMO1-OE) reduced drought tolerance. The FMO1-Ri plants exhibited lower ABA accumulation, higher levels of antioxidant enzyme activities, and less ROS generation compared with the WT and FMO1-OE plants under drought stress. RNA-seq transcriptional analysis revealed the differential expression levels of many drought-responsive genes that were co-expressed with FMO1, including PP2Cs, PYLs, WRKY, and LEA. Using Y2H screening, we found that FMO1 physically interacted with catalase 2 (CAT2), which is an antioxidant enzyme and confers drought resistance. Our findings suggest that tomato FMO1 negatively regulates tomato drought tolerance in the ABA-dependent pathway and modulates ROS homeostasis by directly binding to SlCAT2.
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Drosophila sodium channel 1 (DSC1) encodes a voltage-gated divalent cation channel that mediates neuronal excitability in insects. Previous research revealed that DSC1 knockout Drosophila melanogaster conferred different susceptibility to insecticides, which indicated the vital regulation role of DSC1 under insecticide stress. Haedoxan A (HA) is a lignan compound isolated from Phryma leptostachya, and we found that HA has excellent insecticidal activity and is worthy of further study as a botanical insecticide. Herein, we performed bioassay and electrophysiological experiments to test the biological and neural changes in the larval Drosophila with/without DSC1 knockout in response to HA. Bioassay results showed that knockout of DSC1 reduced the sensitivity to HA in both w1118 (a common wild-type strain in the laboratory) and parats1 (a pyrethroid-resistant strain) larvae. Except for parats1 /DSC1-/- , electrophysiology results implicated that HA delayed the decay rate and increased the frequency of miniature excitatory junctional potentials of Drosophila from w1118 , parats1 , and DSC1-/- strains. Moreover, the neuromuscular synapse excitatory activities of parats1 /DSC1-/- larvae were more sensitive to HA than DSC1-/- larvae, which further confirmed the functional contribution of DSC1 to neuronal excitability. Collectively, these results indicated that the DSC1 channel not only regulated the insecticidal activity of HA, but also maintained the stability of neural circuits through functional interaction with voltage-gated sodium channels. Therefore, our study provides useful information for elucidating the regulatory mechanism of DSC1 in the neural system of insects involving the action of HA derived from P. leptostachya.
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Proteínas de Drosophila , Inseticidas , Canais de Sódio Disparados por Voltagem , Animais , Drosophila melanogaster/fisiologia , Drosophila/metabolismo , Inseticidas/farmacologia , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Canais de Sódio Disparados por Voltagem/genéticaRESUMO
Citrullinated neoepitopes have emerged as key triggers of autoantibodies anti-citrullinated protein antibodies (ACPA) synthesis in rheumatoid arthritis (RA) patients. Apart from their critical role in homeostasis and thrombosis, platelets have a significant contribution to inflammation as well. Although anuclear in nature, platelets have an intricate post-translational modification machinery. Till now, citrullination in platelets and its contribution to trigger autoantibodies ACPA production in RA is an unexplored research direction. Herein, we investigated the expression of peptidylarginine deiminase (PAD) enzymes and citrullinated proteins/peptides in the human platelets and platelet derived microparticles (PDP). Both PAD4 mRNA and protein, but not the other PAD isoforms, are detectable in the human platelets. With a strict filtering criterion,108 citrullination sites present on 76 proteins were identified in the human platelets, and 55 citrullinated modifications present on 37 different proteins were detected in the PDPs. Among them, some are well-known citrullinated autoantigens associated with RA. Citrullinated forms of thrombospondin-1, ß-actin, and platelet factor-4 (also known as CXCL4) are highly immunogenic and bound by autoantibodies ACPA. Furthermore, ACPA from RA sera and synovial fluids recognized citrullinated proteins from platelets and significantly activated them as evidenced by P-selectin upregulation and sCD40 L secretion. These results clearly demonstrate the presence of citrullinated autoantigens in platelets and PDPs, thus could serve as potential targets of ACPA in RA.
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Artrite Reumatoide , Micropartículas Derivadas de Células , Humanos , Autoanticorpos , Micropartículas Derivadas de Células/metabolismo , Citrulina/metabolismo , Desiminases de Arginina em Proteínas , AutoantígenosRESUMO
Ammonium polyphosphate (APP) was successfully modified by a titanate coupling agent which was compounded with benzoxazine (BOZ) and melamine (ME) to become a new type of intumescent flame retardant (Ti-IFR). Ti-IFR and CaCO3 as synergists were utilized to modify polyoxymethylene (POM), and the flame-retardant properties and mechanism of the composites were analyzed by vertical combustion (UL-94), limiting oxygen index (LOI), TG-IR, and cone calorimeter (Cone), etc. The results show that Ti-IFR can enhance the gas phase flame retardant effect, while CaCO3 further strengthens the barrier effect in the condensed phase. When they were used together, they can exert their performance, respectively, at the same time showing excellent synergistic effect. The FR-POM composite with 29% Ti-IFR and 1% CaCO3 can pass the UL-94 V0 level. The LOI reaches 58.2%, the average heat release (Av HRR) is reduced by 81.1% and the total heat release (THR) is decreased by 35.3%.