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BACKGROUND: Coronary atherosclerotic plaques susceptible to acute coronary syndrome have traditionally been characterized by their surrounding cellular architecture. However, with the advent of intravascular imaging, novel mechanisms of coronary thrombosis have emerged, challenging our contemporary understanding of acute coronary syndrome. These intriguing findings underscore the necessity for a precise molecular definition of plaque stability. Considering this, our study aimed to investigate the vascular microenvironment in patients with stable and unstable plaques using spatial transcriptomics. METHODS: Autopsy-derived coronary arteries were preserved and categorized by plaque stability (n=5 patients per group). We utilized the GeoMx spatial profiling platform and Whole Transcriptome Atlas to link crucial histological morphology markers in coronary lesions with differential gene expression in specific regions of interest, thereby mapping the vascular transcriptome. This innovative approach allowed us to conduct cell morphological and spatially resolved transcriptional profiling of atherosclerotic plaques while preserving crucial intercellular signaling. RESULTS: We observed intriguing spatial and cell-specific transcriptional patterns in stable and unstable atherosclerotic plaques, showcasing regional variations within the intima and media. These regions exhibited differential expression of proinflammatory molecules (eg, IFN-γ [interferon-γ], MHC [major histocompatibility complex] class II, proinflammatory cytokines) and prothrombotic signaling pathways. By using lineage tracing through spatial deconvolution of intimal CD68+ (cluster of differentiation 68) cells, we characterized unique, intraplaque subpopulations originating from endothelial, smooth muscle, and myeloid lineages with distinct regional locations associated with plaque instability. In addition, unique transcriptional signatures were observed in vascular smooth muscle and CD68+ cells among plaques exhibiting coronary calcification. CONCLUSIONS: Our study illuminates distinct cell-specific and regional transcriptional alterations present in unstable plaques. Furthermore, we characterize spatially resolved, in situ evidence supporting cellular transdifferentiation and intraplaque plasticity as significant contributors to plaque instability in human coronary atherosclerosis. Our results provide a powerful resource for the identification of novel mediators of acute coronary syndrome, opening new avenues for preventative and therapeutic treatments.
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Doença da Artéria Coronariana , Vasos Coronários , Perfilação da Expressão Gênica , Placa Aterosclerótica , Transcriptoma , Humanos , Vasos Coronários/patologia , Vasos Coronários/metabolismo , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/metabolismo , Perfilação da Expressão Gênica/métodos , Masculino , Ruptura Espontânea , Feminino , Autopsia , Idoso , Pessoa de Meia-Idade , Microambiente CelularRESUMO
The prevention and treatment of gastrointestinal mucosal injury caused by a plateau hypoxic environment is a clinical conundrum due to the unclear mechanism of this syndrome; however, oxidative stress and microbiota dysbiosis may be involved. The Robinia pseudoacacia L. flower, homologous to a functional food, exhibits various pharmacological effects, such as antioxidant, antibacterial, and hemostatic activities. An increasing number of studies have revealed that plant exosome-like nanoparticles (PELNs) can improve the intestinal microbiota and exert antioxidant effects. In this study, the oral administration of Robinia pseudoacacia L. flower exosome-like nanoparticles (RFELNs) significantly ameliorated hypoxia-induced gastric and small intestinal mucosal injury in mice by downregulating hypoxia-inducible factor-1α (HIF-1α) and HIF-2α expression and inhibiting hypoxia-mediated ferroptosis. In addition, oral RFELNs partially improved hypoxia-induced microbial and metabolic disorders of the stomach and small intestine. Notably, RFELNs displayed specific targeting to the gastrointestinal tract. In vitro experiments using gastric and small intestinal epithelial cell lines showed that cell death caused by elevated HIF-1α and HIF-2α under 1% O2 mainly occurred via ferroptosis. RFELNs obviously inhibited HIF-1α and HIF-2α expression and downregulated the expression of NOX4 and ALOX5, which drive reactive oxygen species production and lipid peroxidation, respectively, suppressing ferroptosis under hypoxia. In conclusion, our findings underscore the potential of oral RFELNs as novel, naturally derived agents targeting the gastrointestinal tract, providing a promising therapeutic approach for hypoxia-induced gastric and small intestinal mucosal ferroptosis.
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Fatores de Transcrição Hélice-Alça-Hélice Básicos , Exossomos , Ferroptose , Flores , Mucosa Gástrica , Subunidade alfa do Fator 1 Induzível por Hipóxia , Mucosa Intestinal , Intestino Delgado , Peroxidação de Lipídeos , Nanopartículas , Animais , Ferroptose/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Exossomos/metabolismo , Exossomos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Administração Oral , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Masculino , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Flores/química , Nanopartículas/química , Hipóxia/tratamento farmacológico , Hipóxia/metabolismo , Humanos , Camundongos Endogâmicos C57BLRESUMO
Mastitis, a serious threat to the health and milk production function of dairy cows decreases milk quality. Blood from three healthy cows and three mastitis cows were collected in this study and their transcriptome was sequenced using the Illumina HiSeq platform. Differentially expressed genes (DEGs) were screened according to the |log2FoldChange| > 1 and P-value < 0.05 criteria. Pathway enrichment and functional annotation were performed through KEGG and GO analyses. Finally, the mechanism of the AMP-activated protein kinase (AMPK) mediation of (-)-epigallocatechin-3-gallate (EGCG) to promote lipid metabolism in mastitis cows was analyzed in bovine mammary epithelial cells (BMECs). Transcriptome analysis revealed a total of 825 DEGs, with 474 genes showing increased expression and 351 genes showing decreased expression. The KEGG analysis of DEGs revealed that they were mainly linked to tumour necrosis factor, nuclear factor-κB signalling pathway, and lipid metabolism-related signalling pathway, whereas GO functional annotation found that DEGs were enriched in threonine and methionine kinase activity, cellular metabolic processes, and cytoplasm. AMPK expression, which is involved in several lipid metabolism pathways, was downregulated in mastitis cows. The results of in vitro experiments showed that the inhibition of AMPK promoted the expression of lipid synthesis genes in lipopolysaccharide-induced BMECs and that EGCG could promote lipid synthesis by decreasing the expression of AMPK and downregulating the expression of inflammatory factors in inflammatory BMECs. In conclusion, our study demonstrated that AMPK mediated EGCG to inhabit of inflammatory responses and promote of lipid synthesis in inflammatory BMECs.
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Proteínas Quinases Ativadas por AMP , Catequina , Metabolismo dos Lipídeos , Glândulas Mamárias Animais , Mastite Bovina , Animais , Bovinos , Catequina/análogos & derivados , Catequina/farmacologia , Feminino , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Mastite Bovina/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Perfilação da Expressão Gênica/veterinária , Transcriptoma/efeitos dos fármacosRESUMO
A small molecule disulfide unit technology platform based on dynamic thiol exchange chemistry at the cell membrane has the potential for drug delivery. However, the alteration of the CSSC dihedral angle of the disulfide unit caused by diverse substituents directly affects the effectiveness of this technology platform as well as its own chemical stability. The highly stable open-loop relaxed type disulfide unit plays a limited role in drug delivery due to its low dihedral angle. Here, we have built a novel disulfide unit starship based on the 3,4,5-trihydroxyphenyl skeleton through trigonometric bundling. The intracellular delivery results showed that the trigonometric bundling of the disulfide unit starship effectively promoted cellular uptake without any toxicity, which is far more than 100 times more active than that of equipment with a single disulfide unit in particular. Then, the significant reduction in cell uptake capacity (73-93%) using thiol erasers proves that the trigonometric bundling of the disulfide starship is an endocytosis-independent internalization mechanism via a dynamic covalent disulfide exchange mediated by thiols on the cell surface. Furthermore, analysis of the molecular dynamics simulations demonstrated that trigonometric bundling of the disulfide starship can significantly change the membrane curvature while pushing lipid molecules in multiple directions, resulting in a significant distortion in the membrane structure and excellent membrane permeation performance. In conclusion, the starship system we built fully compensates for the inefficiency deficiencies induced by poor dihedral angles.
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Dissulfetos , Dissulfetos/química , Humanos , Compostos de Sulfidrila/química , Compostos de Sulfidrila/metabolismo , Endocitose , Membrana Celular/metabolismo , Simulação de Dinâmica MolecularRESUMO
Six new 2α-hydroxy ursane triterpenoids, 3α-cis-p-coumaroyloxy-2α,19α-dihydroxy-12-ursen-28-oic acid (1), 3α-trans-p-coumaroyloxy-2α,19α-dihydroxy-12-ursen-28-oic acid (2), 3α-trans-p-coumaroyloxy-2α-hydroxy-12-ursen-28-oic acid (3), 3ß-trans-p-coumaroyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (4), 3ß-trans-feruloyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (5), and 3α-trans-feruloyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (6), along with eleven known triterpenoids (7-17), were isolated from the leaves of Diospyros digyna. Their chemical structures were elucidated by comprehensive analysis of UV, IR, HRESIMS, and NMR spectra. All the isolated compounds were evaluated for their PTP1B inhibitory activity. 3ß-O-trans-feruloyl-2α-hydroxy-urs-12-en-28-oic acid (13) showed the best inhibition activity with an IC50 value of 10.32 ± 1.21 µM. The molecular docking study found that the binding affinity of compound 13 for PTP1B was comparable to that of oleanolic acid (positive control).
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Diospyros , Triterpenos , Simulação de Acoplamento Molecular , Folhas de Planta , Hidroxiácidos , Triterpenos/farmacologiaRESUMO
Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation technique that uses a coil to induce an electric field (E-field) in the brain and modulate its activity. Many applications of TMS call for the repeated execution of E-field solvers to determine the E-field induced in the brain for different coil placements. However, the usage of solvers for these applications remains impractical because each coil placement requires the solution of a large linear system of equations. We develop a fast E-field solver that enables the rapid evaluation of the E-field distribution for a brain region of interest (ROI) for a large number of coil placements, which is achieved in two stages. First, during the pre-processing stage, the mapping between coil placement and brain ROI E-field distribution is approximated from E-field results for a few coil placements. Specifically, we discretize the mapping into a matrix with each column having the ROI E-field samples for a fixed coil placement. This matrix is approximated from a few of its rows and columns using adaptive cross approximation (ACA). The accuracy, efficiency, and applicability of the new ACA approach are determined by comparing its E-field predictions with analytical and standard solvers in spherical and MRI-derived head models. During the second stage, the E-field distribution in the brain ROI from a specific coil placement is determined by the obtained rows and columns in milliseconds. For many applications, only the E-field distribution for a comparatively small ROI is required. For example, the solver can complete the pre-processing stage in approximately 4 hours and determine the ROI E-field in approximately 40 ms for a 100 mm diameter ROI with less than 2% error enabling its use for neuro-navigation and other applications. Highlight: We developed a fast solver for TMS computational E-field dosimetry, which can determine the ROI E-field in approximately 40 ms for a 100 mm diameter ROI with less than 2% error.
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Encéfalo , Estimulação Magnética Transcraniana , Humanos , Estimulação Magnética Transcraniana/métodos , Encéfalo/fisiologia , Cabeça , Radiometria , Imageamento por Ressonância Magnética/métodosRESUMO
Somatostatin receptor type 2 (SSTR2) and thyroid-stimulating hormone receptor (TSHR) display variable expression in primary thyroid tumors and have been implicated as theranostic targets. This study was designed to explore the differential expression of SSTR2 and TSHR in oncocytic (Hurthle cell) carcinoma (OC) vs oncocytic adenoma (OA). We performed a retrospective review for oncocytic neoplasms treated at our institution from 2012 to 2019. Formalin-fixed paraffin-embedded tissue blocks were used for tissue microarray construction. Tissue microarray blocks were cut into 5-µm sections and stained with anti-SSTR2 and anti-TSHR antibodies. Immunostains were analyzed by 3 independent pathologists. χ2 and logistic regression analysis were used to analyze clinical and pathologic variables. Sixty-seven specimens were analyzed with 15 OA and 52 OC. The mean age was 57 years, 61.2% were women, and 70% were White. SSTR2 positivity was noted in 2 OA (13%) and 15 OC (28%; 10 primary, 4 recurrent, and 1 metastatic) (P = .22). TSHR positivity was noted in 11 OA (73%) and 32 OC (62%; 31 primary and 1 metastatic) (P = .40). Those who presented with or developed clinical recurrence/metastasis were more likely to be SSTR2-positive (50% vs 21%; P = .04) and TSHR-negative (64.3% vs 28.9%; P = .02) than primary OC patients. Widely invasive OC was more likely to be SSTR2-positive compared to all other OC subtypes (minimally invasive and angioinvasive) (P = .003). For all patients with OC, TSHR positivity was inversely correlated with SSTR2 positivity (odds ratio, 0.12; CI, 0.03-0.43; P = .006). This relationship was not seen in the patients with OA (odds ratio, 0.30; CI, 0.01-9.14; P = .440). Our results show that recurrent/metastatic OC was more likely to be SSTR2-positive and TSHR-negative than primary OC. Patients with OC displayed a significant inverse relationship between SSTR2 and TSHR expression that was not seen in patients with OA. This may be a key relationship that can be used to prognosticate and treat OCs.
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Neoplasias Epiteliais e Glandulares , Neoplasias da Glândula Tireoide , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Receptores da Tireotropina , Prognóstico , Neoplasias da Glândula Tireoide/patologia , TireotropinaRESUMO
BACKGROUND AND OBJECTIVES: Melasma is a refractory skin disease due to its complex pathogenesis and difficult treatment. Studies have found that human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exos) could serve as a novel cell-free therapeutic strategy in regenerative and esthetic medicine. It could potentially treat melasma, but the skin barrier is a challenge. In this study, we aim to explore the safety and efficacy of hUCMSC-Exos in the treatment of melasma and the means to promote its percutaneous penetration. MATERIALS AND METHODS: In the animal study about the effect of penetration, percutaneous penetration of PKH67-labeled hUCMSC-Exos was studied under microneedles, 1565 nm nonablative fractional laser (NAFL), and a plasma named Peninsula Blue Aurora Shumin Master (PBASM) treatments, observed by confocal laser scanning microscopy. In the clinical application study, 60 patients with melasma treated in our department were divided into four groups. NAFL combined with normal saline treatment was used for Group A. Microneedles, NAFL, and PBASM combined with hUCMSC-Exos treatments were used for Groups B, C, and D, respectively. Each patient received four treatments at 1-month intervals. Assessments were done using the degree of pain posttreatment, melasma area and severity score, improvement rate, physician global assessment score, satisfaction, and complications. RESULTS: In the animal study about the effect of penetration, hUCMSC-Exos can penetrate the deep dermis under microneedles, NAFL, and PBASM treatments. In the clinical application study, compared with Group A, Groups B, C, and D showed significantly improved therapeutic effect and patient satisfaction (p < 0.05), and there was no significant difference among Groups B, C, and D.(p > 0.05). Patients in Group B reported higher pain levels than those in the other three groups (p < 0.05); the treatment experience of patients in Group D was better. CONCLUSION: hUCMSC-Exos can improve the symptoms of melasma safely and effectively. Compared with microneedles, NAFL and PBASM can also achieve a good effect toward promoting penetration. These findings are worthy of exploration and clinical application.
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Exossomos , Melanose , Células-Tronco Mesenquimais , Animais , Humanos , Pele , Melanose/terapia , Células-TroncoRESUMO
Traditional chemical pesticides pose potential threats to human health, the environment, and food safety, and there is an urgent need to develop botanical pesticides that are easily degradable, renewable, and environmentally compatible. This research serves to detect the lethal impacts of Amanita pantherina(DC.:Fr) Schrmm.(Agaricales, Amanitaceae, Amanita), Amanita virgineoides Bas (Agaricales, Amanitaceae, Amanita), Coprinus comatus (O.F.Müll.) Pers. (Agaricales, Psathyrellaceae, Coprinus), Pycnoporus cinnabarinus(Jacq.:Fr) Karst (Polyporales, Polyporaceae, Polyporus) and Phallus rubicundus (Bosc) Fr. (Phallales, Phallaceae, Phallus) on Drosophila melanogaster(Diptera, Drosophilidae, Drosophila), including their effects on lifespan, fecundity, offspring growth and developmental characteristics, antioxidant enzyme activity, peroxide content, and the gene transcription associated with signaling pathways and lifespan of D. melanogaster. The results demonstrated that they all produced lethal effects on D. melanogaster. Female flies were more sensitive to the addition of macrofungi to their diet and have a shorter survival time than male flies. The toxic activity of A. pantherina-supplemented diet was the strongest, so that the D. melanogaster in this group had no offspring. The macrofungal-supplemented diets were able to significantly reduce the activity of antioxidant enzymes, accumulate peroxidation products, up-regulatd the transcription of genes related to signaling pathways, inhibit the expression of longevity genes, reduce the lifespan and fertility of D. melanogaster. Consequently, we hypothetically suggest that medicinal C. comatus, P. cinnabarinus and P. rubicundus hold the potential to be developed into an environmentally friendly biopesticide for fly killing.
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Antioxidantes , Drosophila melanogaster , Masculino , Feminino , Humanos , Animais , Longevidade , Drosophila , FertilidadeRESUMO
To study the chemical constituents from the stems and leaves of Humulus scandens, this study isolated thirteen compounds by different chromatographic methods including silica gel column, ODS, Sephadex LH-20 and preparative HPLC. Based on comprehensive analysis, the chemical structures were elucidated and identified as citrunohin A(1), chrysosplenetin(2), casticin(3), neoechinulin A(4), ethyl 1H-indole-3-carboxylate(5), 3-hydroxyacetyl-indole(6),(1H-indol-3-yl) oxoacetamide(7), inonotusic acid(8), arteannuin B(9), xanthotoxol(10), α-tocopherol quinone(11), eicosanyl-trans-p-coumarate(12), and 9-oxo-(10E,12E)-octadecadienoic acid(13). Among them, compound 1 was a new dihydrochalcone, and the other compounds were obtained from H. scandens for the first time.
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Chalconas , Medicamentos de Ervas Chinesas , Humulus , Indóis , Medicamentos de Ervas Chinesas/químicaRESUMO
BACKGROUND: Opioid prescription for inflammatory bowel disease (IBD)-related pain is on the rise. However, the use of strong opioids can result in severe complications, and even death, in IBD patients. This study aimed to define the role of fentanyl and morphine, two representative strong opioids, in the pathogenesis of dextran sodium sulfate (DSS)- and 2,4,6-trinitrobenzenesulfonic acid solution (TNBS)-induced colitis. METHOD: DSS and TNBS models were induced in C57BL/6J and Balb/c mice, respectively. Disease activity index (DAI), histopathology, enzyme-linked immunosorbent assay (ELISA), multiplex ELISA, and flow cytometry were performed to evaluate the effects of fentanyl and morphine. RESULT: Fentanyl exacerbated DSS- and TNBS-induced colitis, while morphine exhibited no significant immunomodulatory effect. Fentanyl and morphine had no obvious effects on the serum levels of adrenocorticotropic hormone (ACTH), glucocorticoid (GC), and prostaglandin E2 (PGE-2) in DSS and TNBS models. Fentanyl elevated the proportions of Th1 cells, µ-opioid receptor (MOR) + Th1 cells, and MOR + macrophages in the colonic mucosa of DSS-treated mice, and enhanced the proportions of Th1 cells, macrophages, MOR + Th1 cells, and MOR + macrophages in the colonic mucosa of TNBS-treated mice. We found that fentanyl upregulated the levels of inflammatory cytokines/chemokines in MOR + macrophages of the colonic lamina propria mononuclear cells (LPMCs) from DSS-treated mice, whereas it had no effect on the expression of most inflammatory cytokines/chemokines in MOR + macrophages in the colonic LPMCs from TNBS-treated mice. CONCLUSION: Our findings suggest that fentanyl exacerbates murine colitis via Th1 cell- and macrophage-mediated mechanisms, while morphine exhibits no significant immunomodulatory effect.
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Fentanila , Morfina , Camundongos , Animais , Ácido Trinitrobenzenossulfônico/toxicidade , Fentanila/farmacologia , Camundongos Endogâmicos C57BL , Morfina/farmacologiaRESUMO
Splitting water is an important method for producing clean and sustainable hydrogen to replace finite fossil fuels in future energy systems. MoS2 is reported as a promising catalyst without noble metallic elements to accelerate the rate of the electrocatalytic hydrogen evolution reaction. However, there is a real need and strong demand for further improvement of the MoS2-based catalyst. In the present study, a novel amorphous phosphorus-doped MoS2 nanocomposite (P-MoS2) is prepared by a facile hydrothermal method. Compared with crystalline molybdenum disulfide, the amorphous P-doped MoS2 catalyst exhibits much better activity with a smaller Tafel slope of 39 mV dec-1. Moreover, good stability is also demonstrated over the P-MoS2 catalyst in acidic electrolyte. This highly active amorphous P-doped MoS2 catalyst is a promising candidate to facilitate the development of economical hydrogen production systems.
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As highly efficient non-precious metal-based catalysts for the hydrogen evolution reaction (HER), molybdenum carbides have attracted much attention over the phase and structure modification for the improvement of HER performances. In this work, a novel strategy is proposed to modulate phases of molybdenum carbides by boron doping, so that the HER performances can be well controlled. After B-doping, the HER activity of the as-prepared B30 catalyst is significantly enhanced with a much smaller Tafel slope of 78 mV dec-1 than that of the blank one (134 mV dec-1), which originates from the increased amount of active sites, enhanced turnover frequency of each active site and reduced electron transfer resistance. Moreover, this work could broaden our view of phase regulation and provide more possible perspectives for the application in other fields.
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Audio tagging aims to infer descriptive labels from audio clips and it is challenging due to the limited size of data and noisy labels. The solution to the tagging task is described in this paper. The main contributions include the following: an ensemble learning framework is applied to ensemble statistical features and the outputs from the deep classifiers, with the goal to utilize complementary information. Moreover, a sample re-weight strategy is employed to address the noisy label problem within the framework. The approach achieves a mean average precision of 0.958, outperforming the baseline system with a large margin.
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Aprendizado Profundo , Rede Nervosa/fisiologia , Redes Neurais de Computação , Neoplasias Cutâneas/fisiopatologia , Biometria/métodos , HumanosRESUMO
Maintaining colloidal stability in unfriendly environments while retaining surface chemical properties is challenging for fundamental science and crucial for many applications. Here, we report for the first time that by using a low concentration of poly(sodium 4-styrenesulfonate) (PSS), graphene-based amphiphilic Janus nanosheets (AJNs) can be stabilized in high salt brine (3 wt % NaCl and 0.5 wt % CaCl2), whereas the interfacial behavior of the nanosheets is not affected. The adsorption of PSS on the hydrophilic and hydrophobic surfaces of AJNs in brine was investigated experimentally and by molecular dynamics simulations. Simulations further showed that the spatial configuration of absorbed PSS molecules with sulfonate functional groups facing outward favored the generation of electrosteric repulsive interactions. Calculations of the interaction energy between PSS molecules and the nanosheet revealed surface charge as a key parameter to stabilize AJNs in the salt environment, as demonstrated by the case of graphene oxide with higher surface charge. Simulations were also used to examine the interfacial behavior of graphene-based AJNs in biphasic systems. The AJNs, which exhibited asymmetry in surface wettability, remained at the oil/brine interface because of PSS detachment from the hydrophobic surface. The results were subsequently experimentally confirmed, consistent with our previously reported graphene-based AJN fluid prepared in fresh water. The process was thermodynamically supported by the demonstrated negative change of Gibbs free energy. We believe that such a strategy could benefit for the stabilization of other AJNs with surface chemical accessibility under harsh conditions.
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With the aim of evaluating the potential of selenium-containing groups in developing electroluminescent (EL) materials, a series of asymmetric heteroleptic Ir(III) phosphorescent complexes (Ir-Se0F, Ir-Se1F, Ir-Se2F, and Ir-Se3F) have been synthesized by using 2-selenophenylpyridine and one ppy-type (ppy = 2-phenylpyridine) ligand with a fluorinated selenide group. To the best of our knowledge, these complexes represent unprecedented examples of asymmetric heteroleptic Ir(III) phosphorescent emitters bearing selenium-containing groups. Natural transition orbital (NTO) analysis based on optimized geometries of the first triplet state (T1) have shown that the phosphorescent emissions of these Ir(III) complexes dominantly show 3π-π* features of the 2-selenophenylpyridine ligand with slight metal to ligand charge transfer (MLCT) contribution. In comparison with their symmetric parent complex Ir-Se with two 2-selenophenylpyridine ligands, these asymmetric heteroleptic Ir(III) phosphorescent complexes can show much higher phosphorescent quantum yields (ΦP) of ca. 0.90. Both the hole- and electron-trapping ability of these Ir(III) phosphorescent complexes can be enhanced by selenophene and fluorinated selenide groups to improve their EL efficiencies. The EL abilities of these asymmetric heteroleptic Ir(III) phosphorescent emitters fall in the order Ir-Se3F > Ir-Se2F > Ir-Se1F > Ir-Se0F. The highest EL efficiencies have been achieved by Ir-Se3F in the solution-processed OLEDs with external quantum efficiency (ηext), current efficiency (ηL), and power efficiency (ηP) of 19.9%, 65.6 cd A-1, and 57.3 lm W-1, respectively. These encouraging EL results clearly indicate the great potential of selenium-containing groups in developing high-performance Ir(III) phosphorescent emitters.
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The antibiotic compound, rifampicin (RFP), was loaded into porous reinforced ß-tricalcium phosphate (ß-TCP) scaffolds using three different solution adsorption methods. This resulted in drug delivery systems (DDS) generated by vacuum adsorption (VA), dynamic adsorption (DA), and static adsorption (SA). In vitro examination of the drug loading and release profiles of the DDS indicated that the unit mass of RFP loaded into the scaffold by the VA method (0.44 mg/g) was higher than that achieved by SA (0.42 mg/g) or DA (0.38 mg/g) (P < 0.05). The mechanical strength had no significant change after RFP-loading (P > 0.05). Moreover, there were no significant differences among the mechanical strength of three ß-TCP DDS generated by loading RFP using SA, DA, and VA (P > 0.05). In vitro release testing showed an initial burst release of RFP from the three different DDS within the first 3 h and in the first 51 h, the cumulative release of RFP from VA-DDS, DA-DDS, and SA-DDS had reached 56.2, 83.6, and 88.6 %, respectively. Complete RFP release had occurred from VA-DDS, DA-DDS, and SA-DDS after 23, 17, and 15 days, respectively. As the VA-DDS method showed improved RFP loading and a more sustained drug release, this method is recommended for solution adsorption drug loading into porous ß-TCP scaffolds to form a DDS.
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Substitutos Ósseos/síntese química , Fosfatos de Cálcio/química , Implantes de Medicamento/síntese química , Rifampina/administração & dosagem , Rifampina/química , Alicerces Teciduais , Absorção Fisico-Química , Adsorção , Antibióticos Antituberculose/administração & dosagem , Antibióticos Antituberculose/química , Força Compressiva , Difusão , Implantes de Medicamento/administração & dosagem , Porosidade , Resistência à Tração , VácuoRESUMO
OBJECTIVE: To investigate the off-label use of oral glucocorticoids in outpatients. METHODS: The information of outpatient glucocorticoids prescriptions from January 1st to June 30th in 2012 were collected from the information system in our hospital, then the software of Excel was employed to statistically analyze the data including the amount of drugs used in different departments,as well as the age, sex, and diagnosis of the patients. The diagnoses were compared with those included in the labels approved by China Food and Drug Administration and US Food and Drug Administration and domestic and foreign guidelines. RESULTS: It was found that 16.53% of the cases were off-label use,and dexamethasone had the highest proportion (60.50%) of off-label use. Most of the off-label use had evidence support, such as multiple myeloma and myasthenia gravis, while some cases did not, such as epilepsy and sudden deafness. CONCLUSION: The management of off-label use should be further strengthened to promote the safe and rational use of glucocorticoids.
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Uso Off-Label , Administração Oral , China , Epilepsia , Glucocorticoides , Humanos , Pacientes AmbulatoriaisRESUMO
A series of V2O5/CeO2 catalysts with different potassium loadings were prepared to investigate alkali deactivations for selective catalytic reduction of NOx with NH3. An alkali poisoning mechanism could be attributed to surface acidity, reducibility, and NOx adsorption/desorption behaviors. The detailed factors are as follows: (1) decrease of surface acidity suppresses NH3 adsorption by strong bonding of alkali to vanadia (major factor); (2) low reducibility prohibits NH3 activation and NO oxidation by formation bonding of alkali to vanadia and ceria (important factor); (3) active NOx(-) species at low temperature diminish because of coverage of alkali on the surfaces (minor factor); and (4) stable, inactive nitrate species at high temperature increase by generating new basic sites (important factor).
Assuntos
Ácidos/química , Cério/química , Potássio/química , Compostos de Vanádio/química , Adsorção , Catálise , Óxido Nítrico/análise , Óxidos de Nitrogênio/química , Oxirredução , Espectrofotometria Infravermelho , Análise Espectral Raman , Propriedades de Superfície , TemperaturaRESUMO
Polyamidoamine (PAMAM) dendrimers have been widely used as drug carriers, non-viral gene vectors and imaging agents. However, the use of dendrimers in biological system is constrained because of inherent toxicity and organ accumulation. In this study, the strategy of acetylation and PEGylation-acetylation was used to minimize PAMAM dendrimers toxicities and to improve their biodistribution and pharmacokinetics for medical application. PEGylated-acetylated PAMAM (G4-Ac-PEG) dendrimers were synthesized by PEGylation of acetylated PAMAM dendrimer of generation 4 (G4) with acetic anhydride and polyethylene glycol (PEG) 3.4 k. To investigate the cytotoxicity and in vivo biodistribution of the conjugates, in vitro cell viability analysis, Iodine-125 (125I) imaging, tissue distribution and hematoxylin-eosin (HE) staining were performed. We find that acetylation and PEGylation-acetylation essentially eliminates the inherent dendrimer cytotoxicity in vitro. Planar gamma (gamma) camera imaging revealed that all the conjugates were slowly eliminated from the body, and higher abdominal accumulation of acetylation PAMAM dendrimer was observed. Tissue distribution analysis showed that PEGylated-acetylated dendrimers have longer blood retention and lower accumulation in organs such as the kidney and liver than the non-PEGylated-acetylated dendrimers, but acetylation only can significantly increase the accumulation of G4 in the kidney and decrease the concentration in blood. Histology results reveal that no obvious damage was observed in all groups after high dose administration. This study indicates that PEGylation-acetylation could improve the blood retention, decrease organ accumulation, and improve pharmacokinetic profile, which suggests that PEGylation-acetylation provides an alternative method for PAMAM dendrimers modification.