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Sn-doped indium oxide (ITO) semiconductor nano-films are fabricated by plasma-enhanced atomic layer deposition using trimethylindium (TMIn), tetrakis(dimethylamino)tin (TDMASn), and O2plasma as the sources of In, Sn and O, respectively. A shared temperature window of 150 °C- 200 °C is observed for the deposition of ITO nano-films. The introduction of Sn into indium oxide is found to increase the concentration of oxygen into the ITO films and inhibit crystallization. Furthermore, two oxidation states are observed for In and Sn, respectively. With the increment of interfaces of In-O/Sn-O in the ITO films, the relative percentage of In3+ions increases and that of Sn4+decreases, which is generated by interfacial competing reactions. By optimizing the channel component, the In0.77Sn0.23O1.11thin-film transistors (TFTs) demonstrate high performance, includingµFEof 52.7 cm2V-1s-1, and a highION/IOFFof â¼5 × 109. Moreover, the devices show excellent positive bias temperature stress stability at 3 MV cm-1and 85 °C, i.e. a minimalVthshift of 0.017 V after 4 ks stress. This work highlights the successful application of ITO semiconductor nano-films by ALD for TFTs.
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The asymmetric cycloaddition between N-2,2,2-trifluoroethylisatin ketimines and unsymmetrical dicarbonyl-activated alkenes catalyzed by a bifunctional squaramide has been discovered. The present study demonstrates an efficient approach for the regio-, diastereo-, and enantioselective synthesis of densely functionalized 5'-trifluoromethylated 3,2'-pyrrolidinyl spirooxindoles featuring three different types of carbonyl groups.
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Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis during chronic stress is essential for the pathogenesis of depression, and increased activity of cAMP response element binding protein (CREB)-regulated transcription co-activator 1 (CRTC1) in the paraventricular nucleus (PVN) plays a critical role. As a well-investigated microRNA (miRNA), miR-184 has two forms, miR-184-3p and miR-184-5p. Recently, miRNAs target genes predictive analysis and dual-luciferase reporter assays identified an inhibitory role of miR-184-3p on CRTC1 expression. Therefore, we speculated that miR-184-3p regulation was responsible for the effects of chronic stress on CRTC1 in the PVN. Various methods, including the chronic social defeat stress (CSDS) model of depression, behavioral tests, Western blotting, co-immunoprecipitation (Co-IP), quantitative real-time reverse transcription PCR (qRT-PCR), immunofluorescence, and adeno-associated virus (AAV)-mediated gene transfer, were used. CSDS evidently downregulated the level of miR-184-3p, but not miR-184-5p, in the PVN. Genetic knockdown and pharmacological inhibition of miR-184-3p in the PVN induced various depressive-like symptoms (e.g., abnormal behaviors, HPA hyperactivity, enhanced CRTC1 function in PVN neurons, downregulation of hippocampal neurogenesis, and decreased brain-derived neurotrophic factor (BDNF) signaling) in naïve male C57BL/6J mice. In contrast, genetic overexpression and pharmacological activation of miR-184-3p in the PVN produced significant beneficial effects against CSDS. MiR-184-3p in the PVN was necessary for the antidepressant actions of two well-known SSRIs, fluoxetine and paroxetine. Collectively. miR-184-3p was also implicated in the neurobiology of depression and may be a viable target for novel antidepressants.
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The UV/monochloramine (UV/NH2Cl) process, while efficiently eliminating micropollutants, produces toxic byproducts. This study utilized Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to investigate molecular-level changes in natural organic matter (NOM) and to disclose formation pathways of nitro(so) and chloro byproducts in the UV/NH2Cl process. The UV/NH2Cl process significantly increased the saturation and oxidation levels and altered the elemental composition of NOM. Using 15N labeling and a screening workflow, nitro(so) byproducts with nitrogen originating from inorganic sources (i.e., reactive nitrogen species (RNS) and/or NH2Cl) were found to exhibit total intensities comparable to those from NOM. RNS, rather than NH2Cl, played a significant role in incorporating nitrogen into NOM. Through linkage analysis, nitro(so) addition emerged as an important reaction type among the 25 reaction types applied. By using phenol as a representative model compound, the nitro byproducts were confirmed to be mainly generated through the oxidation of nitroso byproducts instead of nitration. Machine learning and SHAP analysis further identified the major molecular indices distinguishing nitro(so) and chloro precursors from non-precursors. This study enhances our fundamental understanding of the mechanisms driving the generation of nitro(so) and chloro byproducts from their precursors in complex NOM during the UV/NH2Cl process.
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Aprendizado de Máquina , Raios Ultravioleta , Espectrometria de Massas , Oxirredução , Cloraminas/químicaRESUMO
Ferroptosis is a form of iron-dependent regulated cell death which is different from apoptosis. Chemically-induced ferroptosis is characterized by an accumulation of lipid reactive oxygen species (ROS) in the cells. A number of earlier studies have suggested the involvement of mitochondrial ROS in ferroptosis, and the present study seeks to further investigate the role of mitochondrial ROS in the induction of chemically-induced ferroptotic cell death. We find that during erastin-induced, glutathione depletion-associated ferroptosis, mitochondrial ROS accumulation is an important late event, which likely is involved in the final execution of ferroptotic cell death. The mitochondrion-originated ROS is found to accumulate in large quantities inside the nuclei during the late phases of erastin-induced ferroptosis. Completion of the late-phase accumulation of mitochondrion-produced ROS inside the nucleus of a cell likely marks an irreversible point in the cell death process. Similarly, accumulation of large amounts of mitochondrion-produced ROS inside the nucleus is also observed in the late phases of RSL3-induced ferroptosis. The results of this study indicate that the mitochondrial ROS play an important role in the final steps of both erastin- and RSL3-induced ferroptotic cell death.
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BACKGROUND: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. As liver cancer often presents no noticeable symptoms in its early stages, most patients are diagnosed at an advanced stage, complicating treatment. Therefore, the identification of new biomarkers is crucial for the early detection and treatment of HCC. Research on exportin-5 (XPO5) could offer new avenues for early diagnosis and improve treatment strategies. AIM: To explore the role of XPO5 in HCC progression and its potential as a prognostic biomarker. METHODS: This study assessed XPO5 mRNA expression in HCC using The Cancer Genome Atlas, TIMER, and International Cancer Genome Consortium databases, correlating it with clinical profiles and disease progression. We performed in vitro experiments to examine the effect of XPO5 on liver cell growth. Gene Set Enrichment Analysis, Kyoto Encyclopedia of Genes and Genomes, and Gene Ontology were used to elucidate the biological roles and signaling pathways. We also evaluated XPO5's impact on immune cell infiltration and validated its prognostic potential using machine learning. RESULTS: XPO5 was significantly upregulated in HCC tissues, correlating with tumor grade, T-stage, and overall survival, indicating poor prognosis. Enrichment analyses linked high XPO5 expression with tumor immunity, particularly CD4 T cell memory activation and macrophage M0 infiltration. Drug sensitivity tests identified potential therapeutic agents such as MG-132, paclitaxel, and WH-4-023. Overexpression of XPO5 in HCC cells, compared to normal liver cells, was confirmed by western blotting and quantitative real-time polymerase chain reaction. The lentiviral transduction-mediated knockdown of XPO5 significantly reduced cell proliferation and metastasis. Among the various machine learning algorithms, the C5.0 decision tree algorithm achieved accuracy rates of 95.5% in the training set and 92.0% in the validation set. CONCLUSION: Our analysis shows that XPO5 expression is a reliable prognostic indicator for patients with HCC and is significantly associated with immune cell infiltration.
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To enhance the electrical safe operation area (eSOA) of laterally diffused metal oxide semiconductor (LDMOS) transistors, a novel reduced surface electric field (Resurf) structure in the n-drift region is proposed, which was fabricated by ion implantation at the surface of the LDMOS drift region and by drift region dimension optimization. Technology computer-aided design (TCAD) simulations show that the optimal value of Resurf ion implantation dose 1 × 1012 cm-2 can reduce the surface electric field in the n-drift region effectively, thereby improving the ON-state breakdown voltage of the device (BVon). In addition, the extended n-drift region length of the Ld design also improves device BVon significantly, and is aimed at reducing the current density and the electric field, and eventually suppressing the n-drift region impact ionization. The results show that the novel 60 V nLDMOS has a competitive BVon performance of 106.9 V, which is about 20% higher than that of the conventional one. Meanwhile, the OFF-state breakdown voltage of the device (BVoff) of 88.4 V and the specific ON-resistance (RON,sp) of 129.7 mΩâ mm2 exhibit only a slight sacrifice.
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BACKGROUND: Emerging data has demonstrated that in mature neurons, SorCS2 localizes to the postsynaptic density of dendritic spines and facilitates plasma membrane sorting of TrkB by interacting with it, transmitting positive signaling from BDNF on neurons. Thus, it is possible that SorCS2 plays a role in the pathophysiology of depression by regulating the BDNF-TrkB system. METHODS: In the present study, SorCS2 expression in different brain regions [hippocampus, medial prefrontal cortex (mPFC), hypothalamus, amygdala, ventral tegmental area (VTA), and nucleus accumbens (NAc)] was thoroughly investigated in the chronic social defeat stress (CSDS) and chronic unpredictable mild stress (CUMS) models of depression. The changes in depressive-like behaviors, the hippocampal BDNF signaling cascade, and amounts of hippocampal immature neurons were further investigated after SorCS2 overexpression by microinjection of the adenovirus associated virus vector containing the coding sequence of mouse SorCS2 (AAV-SorCS2) into the hippocampus of mice exposed to CSDS or CUMS. RESULTS: It was found that both CSDS and CUMS significantly decreased the protein and mRNA expression of SorCS2 in the hippocampus but not in other brain regions. Chronic stress also notably downregulated the level of hippocampal SorCS2-TrkB binding in mice. In contrast, AAV-based genetic overexpression of hippocampal SorCS2 fully reversed the chronic stress-induced not only depressive-like behaviors but also decreased SorCS2-TrkB binding, BDNF signaling pathway, and amounts of immature neurons in the hippocampus of mice. CONCLUSION: All these results suggest that enhancing the hippocampal SorCS2 expression protects against chronic stress, producing antidepressant-like actions. Hippocampal SorCS2 may participate in depression neurobiology and be a potential antidepressant target. SIGNIFICANCE STATEMENT: Targeting of proteins to distinct subcellular compartments is essential for neuronal activity and modulated by VPS10P domain receptors which include SorCS2. In mature neurons, SorCS2 localizes to the postsynaptic density of dendritic spines and facilitates plasma membrane sorting of TrkB by interacting with it, transmitting positive signaling from BDNF on neurons. Our study is the first direct evidence preliminarily showing that SorCS2 plays a role in depression neurobiology. It was found that chronic stress induced not only depressive-like behaviors but also decreased SorCS2 expression in the hippocampus. Chronic stress did not affect SorCS2 expression in the mPFC, hypothalamus, amygdala, VTA, or NAc. In contrast, genetic overexpression of hippocampal SorCS2 prevented against chronic stress, producing antidepressant-like actions in mice. Thus, hippocampal SorCS2 is a potential participant underlying depression neurobiology and may be a novel antidepressant target. Our study may also extend the knowledge of the neurotrophic hypothesis of depression.
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Fator Neurotrófico Derivado do Encéfalo , Depressão , Hipocampo , Camundongos Endogâmicos C57BL , Receptor trkB , Estresse Psicológico , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Hipocampo/metabolismo , Estresse Psicológico/metabolismo , Camundongos , Masculino , Receptor trkB/metabolismo , Depressão/metabolismo , Transdução de Sinais , Modelos Animais de Doenças , Comportamento Animal , Proteínas Tirosina Quinases/metabolismo , Proteínas Tirosina Quinases/genética , Neurônios/metabolismoRESUMO
Objective: This study investigated the impact of occupational mercury (Hg) exposure on human gene transcription and expression, and its potential biological mechanisms. Methods: Differentially expressed genes related to Hg exposure were identified and validated using gene expression microarray analysis and extended validation. Hg-exposed cell models and PTEN low-expression models were established in vitro using 293T cells. PTEN gene expression was assessed using qRT-PCR, and Western blotting was used to measure PTEN, AKT, and PI3K protein levels. IL-6 expression was determined by ELISA. Results: Combined findings from gene expression microarray analysis, bioinformatics, and population expansion validation indicated significant downregulation of the PTEN gene in the high-concentration Hg exposure group. In the Hg-exposed cell model (25 and 10 µmol/L), a significant decrease in PTEN expression was observed, accompanied by a significant increase in PI3K, AKT, and IL-6 expression. Similarly, a low-expression cell model demonstrated that PTEN gene knockdown led to a significant decrease in PTEN protein expression and a substantial increase in PI3K, AKT, and IL-6 levels. Conclusion: This is the first study to report that Hg exposure downregulates the PTEN gene, activates the PI3K/AKT regulatory pathway, and increases the expression of inflammatory factors, ultimately resulting in kidney inflammation.
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Inflamação , Mercúrio , PTEN Fosfo-Hidrolase , Humanos , Regulação para Baixo , Células HEK293 , Inflamação/induzido quimicamente , Inflamação/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-6/sangue , Mercúrio/toxicidade , Exposição Ocupacional/efeitos adversos , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Traumatic brain injury (TBI) is a major cause of morbidity and mortality globally. We unveiled the diagnostic value of serum NLRP3, metalloproteinase-9 (MMP-9) and interferon-γ (IFN-γ) levels in post-craniotomy intracranial infections and hydrocephalus in patients with severe craniocerebral trauma to investigate the high risk factors for these in patients with TBI, and the serological factors predicting prognosis, which had a certain clinical predictive value. Study subjects underwent bone flap resection surgery and were categorized into the intracranial infection/hydrocephalus/control (without postoperative hydrocephalus or intracranial infection) groups, with their clinical data documented. Serum levels of NLRP3, MMP-9 and IFN-γ were determined using ELISA kits, with their diagnostic efficacy on intracranial infections and hydrocephalus evaluated by receiver operating characteristic curve analysis. The independent risk factors affecting postoperative intracranial infections and hydrocephalus were analysed by logistic multifactorial regression. The remission after postoperative symptomatic treatment was counted. The intracranial infection/control groups had significant differences in Glasgow Coma Scale (GCS) scores, opened injury, surgical time and cerebrospinal fluid leakage, whereas the hydrocephalus and control groups had marked differences in GCS scores, cerebrospinal fluid leakage and subdural effusion. Serum NLRP3, MMP-9 and IFN-γ levels were elevated in patients with post-craniotomy intracranial infections/hydrocephalus. The area under the curve values of independent serum NLRP3, MMP-9, IFN-γ and their combination for diagnosing postoperative intracranial infection were 0.822, 0.722, 0.734 and 0.925, respectively, and for diagnosing hydrocephalus were 0.865, 0.828, 0.782 and 0.957, respectively. Serum NLRP3, MMP-9 and IFN-γ levels and serum NLRP3 and MMP-9 levels were independent risk factors influencing postoperative intracranial infection and postoperative hydrocephalus, respectively. Patients with hydrocephalus had a high remission rate after postoperative symptomatic treatment. Serum NLRP3, MMP-9 and IFN-γ levels had high diagnostic efficacy in patients with postoperative intracranial infection and hydrocephalus, among which serum NLRP3 level played a major role.
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Hidrocefalia , Interferon gama , Metaloproteinase 9 da Matriz , Proteína 3 que Contém Domínio de Pirina da Família NLR , Humanos , Masculino , Metaloproteinase 9 da Matriz/sangue , Feminino , Pessoa de Meia-Idade , Interferon gama/sangue , Adulto , Hidrocefalia/cirurgia , Traumatismos Craniocerebrais/complicações , Traumatismos Craniocerebrais/sangue , Complicações Pós-Operatórias/sangue , Idoso , Fatores de Risco , Biomarcadores/sangue , Adulto JovemRESUMO
The assessment of atherosclerosis (AS) progression has emerged as a prominent area of research. Monitoring various pathological features of foam cell (FC) formation is imperative to comprehensively assess AS progression. Herein, a simple benzospiropyran-julolidine-based probe, BSJD, with switchable dual-color imaging ability was developed. This probe can dynamically and reversibly adjust its molecular structure and fluorescent properties in different polar and pH environments. Such a polarity and pH dual-responsive characteristic makes it superior to single-responsive probes in dual-color imaging of lipid droplets (LDs) and lysosomes as well as monitoring their interaction. By simultaneously tracking various pathological features, including LD accumulation and size changes, lysosome dysfunction, and dynamically regulated lipophagy, more comprehensive information can be obtained for multiparameter assessment of FC formation progression. Using BSJD, not only the activation of lipophagy in the early stages and inhibition in the later phases during FC formation are clearly observed but also the important roles of lipophagy in regulating lipid metabolism and alleviating FC formation are demonstrated. Furthermore, BSJD is demonstrated to be capable of rapidly imaging FC plaque sites in AS mice with fast pharmacokinetics. Altogether, BSJD holds great promise as a dual-color organelle-imaging tool for investigating disease-related LD and lysosome changes and their interactions.
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Corantes Fluorescentes , Células Espumosas , Gotículas Lipídicas , Corantes Fluorescentes/química , Células Espumosas/metabolismo , Células Espumosas/patologia , Animais , Camundongos , Gotículas Lipídicas/metabolismo , Gotículas Lipídicas/química , Lisossomos/metabolismo , Aterosclerose/metabolismo , Aterosclerose/diagnóstico por imagem , Aterosclerose/patologia , Imagem Óptica , Humanos , Células RAW 264.7 , Concentração de Íons de Hidrogênio , CorRESUMO
Polymeric lattice materials with micro/nano-structures are attractive for applications in a wide range of bioengineering systems. Resent experimental results show that elastic constitutive law of polymer materials is in line with the Cosserat elasticity. In this work, a Cosserat continuum spectral element method is employed to explore the size-dependent mechanical performance of polymer polymeric lattice with horseshoe microstructures, efficiently. The mechanical performance predicted by the proposed method agrees very well with the experiment data. Our results demonstrate that size effects are significant in polymeric lattice materials. The size-dependent negative Poisson's ratio is found in the polymeric lattice materials with the same topological structure due to the size effect caused by the Cosserat elasticity of the polymer materials. It could be implied that it is possible to continuously adjust the negative Poisson's ratio of the polymeric lattice material over a wide range by only changing its microstructural size.
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Polímeros , ElasticidadeRESUMO
Ferroptosis is a recently identified form of regulated cell death, characterized by excessive iron-dependent lipid peroxidation. Recent studies have demonstrated that protein disulfide isomerase (PDI) is an important mediator of chemically induced ferroptosis and also a new target for protection against ferroptosis-associated cell death. In the present study, we identified that 4-hydroxyestrone (4-OH-E1), a metabolic derivative of endogenous estrogen, is a potent small-molecule inhibitor of PDI, and can strongly protect against chemically induced ferroptotic cell death in the estrogen receptor-negative MDA-MB-231 human breast cancer cells. Pull-down and CETSA assays demonstrated that 4-OH-E1 can directly bind to PDI both in vitro and in intact cells. Computational modeling analysis revealed that 4-OH-E1 forms two hydrogen bonds with PDI His256, which is essential for its binding interaction and thus inhibition of PDI's catalytic activity. Additionally, PDI knockdown attenuates the protective effect of 4-OH-E1 as well as cystamine (a known PDI inhibitor) against chemically induced ferroptosis in human breast cancer cells. Importantly, inhibition of PDI by 4-OH-E1 and cystamine or PDI knockdown by siRNAs each markedly reduces iNOS activity and NO accumulation, which has recently been demonstrated to play an important role in erastin-induced ferroptosis. In conclusion, this study demonstrates that 4-OH-E1 is a novel inhibitor of PDI and can strongly inhibit ferroptosis in human breast cancer cells in an estrogen receptor-independent manner. The mechanistic understanding gained from the present study may also aid in understanding the estrogen receptor-independent cytoprotective actions of endogenous estrogen metabolites in many noncancer cell types.
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Neoplasias da Mama , Hidroxiestronas , Piperazinas , Isomerases de Dissulfetos de Proteínas , Humanos , Feminino , Isomerases de Dissulfetos de Proteínas/química , Neoplasias da Mama/tratamento farmacológico , Cistamina , Morte Celular , Estrogênios , Receptores de EstrogênioRESUMO
Natural organic matter (NOM) is a major sink of radicals in advanced oxidation processes (AOPs) and understanding the transformation of NOM is important in water treatment. By using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in conjunction with machine learning, we comprehensively investigated the reactivity and transformation of NOM, and the formation of organosulfates during the UV/peroxydisulfate (PDS) process. After 60 min UV/PDS treatment, the CHO formula number and dissolved organic carbon concentration significantly decreased by 83.4 % and 74.8 %, respectively. Concurrently, the CHOS formula number increased substantially from 0.7 % to 20.5 %. Machine learning identifies DBE and AImod as the critical characteristics determining the reactivity of NOM during UV/PDS treatment. Furthermore, linkage analysis suggests that decarboxylation and dealkylation reactions are dominant transformation pathways, while the additions of SO3 and SO4 are also non-negligible. According to SHAP analysis, the m/z, number of oxygens, DBE and O/C of NOM were positively correlated with the formation of organosulfates in UV/PDS process. 92 organosulfates were screened out by precursor ion scan of HPLC-MS/MS and verified by UPLC-Q-TOF-MS, among which, 7 organosufates were quantified by authentic standards with the highest concentrations ranging from 2.1 to 203.0 ng Lâ1. In addition, the cytotoxicity of NOM to Chinese Hamster Ovary (CHO) cells increased by 13.8 % after 30 min UV/PDS treatment, likely responsible for the formation of organosulfates. This is the first study to employ FT-ICR MS combined with machine learning to identify the dominant NOM properties affecting its reactivity and confirmed the formation of organosulfates from sulfate radical oxidation of NOM.
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Aprendizado de Máquina , Sulfatos , Sulfatos/química , Animais , Células CHO , Raios Ultravioleta , Cricetulus , Espectrometria de Massas , Purificação da Água/métodos , OxirreduçãoRESUMO
Neurological disorders are closely linked to the alterations in cell membrane permeability (CMP) and mitochondrial membrane potential (MMP). Changes in CMP and MMP may lead to damage and death of nerve cells, thus triggering the onset and progression of neurological diseases. Therefore, monitoring the changes of these two physiological parameters not only benefits the accurate assessment of nerve cell health status, but also enables providing key information for the diagnosis and treatment of neurological diseases. However, the simultaneous monitoring of these two cellular physiological parameters is still challenging. Herein, we design and synthesize two quinolinium-carbazole-derivated fluorescent probes (OQ and PQ). As isomers, the only difference in their chemical structures is the linking position of the carbazole unit in quinoline rings. Strikingly, such a subtle difference endows OQ and PQ with significantly different organelle-staining behaviors. PQ mainly targets at the nucleus, OQ can simultaneously stain cell membranes and mitochondria in normal cells, and performs CMP and MMP-dependent translocation from the cell membrane to mitochondria then to the nucleus, thus holding great promise as an intracellular translocation probe to image the changes of CMP and MMP. After unraveling the intrinsic mechanism of their different translocation abilities by combining experiments with molecular dynamics simulations and density functional theory calculations, we successfully used OQ to monitor the continuous changes of CMP and MMP in three neurological disease-related cell models, including oxidative stress-damaged, Parkinson's disease, and virus-infected ones. Besides providing a validated imaging tool for monitoring cellular physiological parameters, this work paves a promising route for designing intracellular translocation probes to analyze cellular physiological parameters associated with various diseases.
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Corantes Fluorescentes , Potencial da Membrana Mitocondrial , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Humanos , Doenças do Sistema Nervoso , Teoria da Densidade Funcional , Permeabilidade da Membrana Celular , Carbazóis/química , Estrutura Molecular , Animais , Imagem ÓpticaRESUMO
Deterioration in mechanical performances and aging resistance due to the introduction of flame retardants is a major obstacle for bio-based fire-safety polypropylene (PP). Herein, we reported a kind of functionalized lignin nanoparticles assembled with MXene (MX@LNP), and applied it to construct the flame-retardant PP composites (PP-MA) with superior fire safety, excellent mechanical performance, electromagnetic shielding effects and aging resistance. Specifically, the PP-MA doped with only 18 wt% flame-retardant additives (PP-MA18) achieved the UL-94 V-0 rating. In comparison to pure PP, PP-MA18 presented a greatly decreased peak of heat release rate (pHRR), total heat rate (THR), and peak smoke production rate (pSPR) by 79.7 %, 69.0 % and 75.8 %, respectively, and satisfactory decrease in total flammable and toxic volatiles evolved. The formed fine solid microstructure of carbon residuals effectively promoted the compactness of char layers. More importantly, the nano-effect and the strong interface interaction between the complexed MX@LNP and PP enhanced the tensile strength (45.78 MPa) and elongation at break (725.95 %) of PP-MA. Additionally, the significant ultraviolet absorption and electromagnetic wave dissipation performance of MXene and lignin enabled excellent aging resistance and electromagnetic shielding effects of PP-MA compared with PP. This achieved MX@LNP afforded a novel approach for developing flame retardant materials with excellent application performance.
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Retardadores de Chama , Nanopartículas , Nitritos , Elementos de Transição , Lignina , Polipropilenos , Fenômenos EletromagnéticosRESUMO
Objectives: CD4+ T cell helper and regulatory function in human cancers has been well characterised. However, the definition of tumor-infiltrating CD4+ T cell exhaustion and how it contributes to the immune response and disease progression in human gastric cancer (GC) remain largely unknown. Methods: A total of 128 GC patients were enrolled in the study. The expression of CD39 and PD-1 on CD4+ T cells in the different samples was analysed by flow cytometry. GC-infiltrating CD4+ T cell subpopulations based on CD39 expression were phenotypically and functionally assessed. The role of CD39 in the immune response of GC-infiltrating T cells was investigated by inhibiting CD39 enzymatic activity. Results: In comparison with CD4+ T cells from the non-tumor tissues, significantly more GC-infiltrating CD4+ T cells expressed CD39. Most GC-infiltrating CD39+CD4+ T cells exhibited CD45RA-CCR7- effector-memory phenotype expressing more exhaustion-associated inhibitory molecules and transcription factors and produced less TNF-α, IFN-γ and cytolytic molecules than their CD39-CD4+ counterparts. Moreover, ex vivo inhibition of CD39 enzymatic activity enhanced their functional potential reflected by TNF-α and IFN-γ production. Finally, increased percentages of GC-infiltrating CD39+CD4+ T cells were positively associated with disease progression and patients' poorer overall survival. Conclusion: Our study demonstrates that CD39 expression defines GC-infiltrating CD4+ T cell exhaustion and their immunosuppressive function. Targeting CD39 may be a promising therapeutic strategy for treating GC patients.
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Carbazole derivatives can be used as antioxidants in the lubricating oil industry. The alkylation of carbazole with 2-chloro-2-methylpropane and 2-bromopropane catalyzed by anhydrous aluminum chloride was studied. Initially, 3,6-di-iso-propylcarbazole and 3,6-di-tert-butylcarbazole were using dichloromethane and dibromomethane as solvents at room temperature, respectively. The synthesis conditions were optimized. Subsequently, the effects of reaction time, catalyst dosage, and molar ratio of carbazole to alkylating agent were investigated, and orthogonal experiments were performed. The structures of the carbazole derivatives were characterized by Fourier infrared spectroscopy (FT-IR), mass spectrum (MS) and nuclear magnetic resonance spectroscopy (NMR). The thermal stability of the synthesized carbazole derivatives was investigated by differential scanning calorimetry (DSC). The carbazole derivatives were added into the lubricating oil with a mass fraction of 0.8% and the miscibility, stability and oxidation resistance of the mixed system were evaluated by mechanical stirring and a rotary pressure vessel oxidation test (RPVOT). The DSC results showed that there was good thermal stability for the carbazole derivatives. The mechanical stirring method revealed good solubility and stability for the mixture of oil and carbazole derivatives. The RPVOT results showed that isopropyl carbazole derivatives could increase the oxidation induction period of lubricating oil to 1.39 times, and tert-butyl carbazole derivatives could increase the oxidation induction period of lubricating oil to 1.91 times. The antioxidant effect of tert-butyl carbazole derivatives was better than that of isopropyl carbazole derivatives.
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The ectonucleotidase CD39 has been regarded as a promising immune checkpoint in solid tumors. However, the expression of CD39 by tumor-infiltrating CD8+ T cells as well as their potential roles and clinical implications in human gastric cancer (GC) remain largely unknown. Here, we found that GC-infiltrating CD8+ T cells contained a fraction of CD39hi cells that constituted about 6.6% of total CD8+ T cells in tumors. These CD39hi cells enriched for GC-infiltrating CD8+ T cells with features of exhaustion in transcriptional, phenotypic, metabolic and functional profiles. Additionally, GC-infiltrating CD39hiCD8+ T cells were also identified for tumor-reactive T cells, as these cells expanded in vitro were able to recognize autologous tumor organoids and induced more tumor cell apoptosis than those of expanded their CD39int and CD39-CD8+ counterparts. Furthermore, CD39 enzymatic activity controlled GC-infiltrating CD39hiCD8+ T cell effector function, and blockade of CD39 efficiently enhanced their production of cytokines IFN-γ and TNF-α. Finally, high percentages of GC-infiltrating CD39hiCD8+ T cells correlated with tumor progression and independently predicted patients' poor overall survival. These findings provide novel insights into the association of CD39 expression level on CD8+ T cells with their features and potential clinical implications in GC, and empowering those exhausted tumor-reactive CD39hiCD8+ T cells through CD39 inhibition to circumvent the suppressor program may be an attractive therapeutic strategy against GC.
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Linfócitos T CD8-Positivos , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Citocinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Flame retardants containing biomass receive growing interest in environmental friendliness and sustainability but usually face the low flame-retardant efficiency and deterioration on mechanical property of matrix. Herein, a calcium gluconate-based flame retardant (CG@APP) was chemically prepared using calcium gluconate (CG) and ammonium polyphosphate (APP) via ion exchange reaction, and enabled the excellent fire safety and mechanical enhancement for epoxy resin (EP). The resulted EP composites containing 6 wt% CG@APP (EP/CG@APP6) exhibited V-0 ratings in UL-94 test. Furthermore, with respect to EP/APP6, the peak of heat release rate (pHRR) and peak of smoke production rate (pSPR) of EP/CG@APP6 decreased by 70.5 % and 50.0 %, respectively. The well synergistic flame-retardant mechanism of CG@APP between gaseous and solid phases was revealed to generate denser and more continuous charring residuals, which could do well work on insulation for heat transfer and fuel diffusion. In addition, the shell rich in hydroxyl group and Ca2+ on the surface of CG@APP well enhanced the interface compatibility through the hydrogen bond and coordinated bond, thus the tensile strength, flexural strength and impact strength of EP/CG@APP6 increased by 18.2 %, 4.5 % and 9.1 % compared with pure EP, respectively. This work provided a simple and sustainable way to construct excellent fire-safety composites.