235 research outputs found

    A state-dependent delay equation with chaotic solutions

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    We exhibit a scalar-valued state-dependent delay differential equation x 0 (t) = f(x(t − d(xt))) that has a chaotic solution. This equation has continuous (semi-strictly) monotonic negative feedback, and the quantity t − d(xt) is strictly increasing along solutions

    Corrigendum to "A state-dependent delay equation with chaotic solutions" - Electron. J. Qual. Theory Differ. Equ. 2019, No. 22, 1-20

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    We correct an error in “A state-dependent delay equation with chaotic solutions” [Electron. J. Qual. Theory Differ. Equ. 2019, No. 22, 1–20]

    Characteristics and Applications of Biochars Derived from Wastewater Solids

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    Pyrolysis is a thermochemical decomposition process that can be used to generate pyrolysis gas (py-gas), bio-oil, and biochar as well as energy from biomass. Biomass from agricultural waste and other plant-based materials has been the predominant pyrolysis research focus. Water resource recovery facilities also produce biomass, referred to as wastewater solids, that could be a viable pyrolysis feedstock. Water resource recovery facilities are central collection and production sites for wastewater solids. While the utilization of biochar from a variety of biomass types has been extensively studied, the utilization of wastewater biochars has not been reviewed in detail. This review compares the characteristics of wastewater biochars to more conventional biochars and reviews specific applications of wastewater biochar. Wastewater biochar is a potential candidate to sorb nutrients or organic contaminants from contaminated wastewater streams. While biochar has been used as a beneficial soil amendment for agricultural applications, specific research on wastewater biochar is lacking and represents a critical knowledge gap. Based on the studies reviewed, if biochar is applied to land it will contain less organic micropollutant mass than conventional wastewater solids, and polycyclic aromatic hydrocarbons are not likely to be a concern if pyrolysis is conducted above 700 °C. Wastewater biochar is likely to serve as a better catalyst to convert bio-oil to py-gas than other conventional biochars because of the inherently higher metal (e.g., Ca and Fe) content. The use of wastewater biochar alone as a fuel is also discussed. Finally, an integrated wastewater treatment process that produces and uses wastewater biochar for a variety of food, energy, and water (FEW) applications is proposed

    Epigenetic dynamics shaping melanophore and iridophore cell fate in zebrafish

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    BACKGROUND: Zebrafish pigment cell differentiation provides an attractive model for studying cell fate progression as a neural crest progenitor engenders diverse cell types, including two morphologically distinct pigment cells: black melanophores and reflective iridophores. Nontrivial classical genetic and transcriptomic approaches have revealed essential molecular mechanisms and gene regulatory circuits that drive neural crest-derived cell fate decisions. However, how the epigenetic landscape contributes to pigment cell differentiation, especially in the context of iridophore cell fate, is poorly understood. RESULTS: We chart the global changes in the epigenetic landscape, including DNA methylation and chromatin accessibility, during neural crest differentiation into melanophores and iridophores to identify epigenetic determinants shaping cell type-specific gene expression. Motif enrichment in the epigenetically dynamic regions reveals putative transcription factors that might be responsible for driving pigment cell identity. Through this effort, in the relatively uncharacterized iridophores, we validate alx4a as a necessary and sufficient transcription factor for iridophore differentiation and present evidence on alx4a\u27s potential regulatory role in guanine synthesis pathway. CONCLUSIONS: Pigment cell fate is marked by substantial DNA demethylation events coupled with dynamic chromatin accessibility to potentiate gene regulation through cis-regulatory control. Here, we provide a multi-omic resource for neural crest differentiation into melanophores and iridophores. This work led to the discovery and validation of iridophore-specific alx4a transcription factor

    Imaging Electronic Correlations in Twisted Bilayer Graphene near the Magic Angle

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    Twisted bilayer graphene with a twist angle of around 1.1{\deg} features a pair of isolated flat electronic bands and forms a strongly correlated electronic platform. Here, we use scanning tunneling microscopy to probe local properties of highly tunable twisted bilayer graphene devices and show that the flat bands strongly deform when aligned with the Fermi level. At half filling of the bands, we observe the development of gaps originating from correlated insulating states. Near charge neutrality, we find a previously unidentified correlated regime featuring a substantially enhanced flat band splitting that we describe within a microscopic model predicting a strong tendency towards nematic ordering. Our results provide insights into symmetry breaking correlation effects and highlight the importance of electronic interactions for all filling factors in twisted bilayer graphene.Comment: Main text 9 pages, 4 figures; Supplementary Information 25 page

    CRT-700.05 Impella Utilization in High-Risk Percutaneous Coronary Intervention Mitigates the Risks of Procedural and Clinical Adverse Events Independent of Left Ventricular Ejection Fraction: The Protect III Study

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    Background: Left ventricular (LV) dysfunction is associated with an increased risk of adverse events in patients undergoing percutaneous coronary intervention (PCI). However, the impact of LV ejection fraction (LVEF) on the outcomes of Impella-supported high-risk PCI (HRPCI) is unknown. Methods: Patients enrolled in the prospective, multicenter, and observational PROTECT III study from March 2017 to March 2020 who underwent Impella-supported HRPCI at the operator’s discretion (non-cardiogenic shock). Patients were divided into three tertiles (T) based on baseline LVEF: T1 (the lowest), T2, and T3 (the highest). The primary outcome is the rate of 90-day major adverse cardiac and cerebrovascular events (MACCE), defined as the composite of all-cause death, myocardial infarction, stroke/transient ischemic attack, and repeated revascularization as adjudicated by an independent CEC. Results: Of 1237 patients, 940 with available baseline LVEF were analyzed. T1 included 353 patients (mean LVEF 19.6±4.7), T2 included 274 patients (mean LVEF 32.2±3.5), and T3 included 313 patients (mean LVEF 52.6±9.2). Patients in the higher tertiles were older, more likely to be females, presented more with acute coronary syndrome, and had more frequent left main disease. Also, severely calcified lesions and atherectomy utilization were more frequent in the higher tertiles. The rates of 90-day MACCE were comparable across all tertiles. Furthermore, PCI-related complications and 1-year mortality were also comparable (Table). After multivariable adjustment, 90-day MACCE was not significantly different between the LVEF tertiles (p=0.32). Conclusion: In patients with HRPCI supported by Impella, the rates of in-hospital adverse events, PCI-related complications, 90-day MACCE, and 1-year mortality were comparable among the different LVEF tertiles

    Strain-Tuning of 2D and 3D Charge-Density Waves in High-Temperature Superconducting YBa2_{2}Cu3_{3}Oy_{\rm{y}}

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    Uniaxial pressure experiments in underdoped YBa2_{2}Cu3_{3}Oy_{\rm{y}} provide an efficient approach to the control of the competition between charge-density waves (CDWs) and superconductivity. It can enhance the correlation volume of ubiquitous short-range CDW correlations and above a critical value, even induce a long-range CDW order otherwise only accessible through the suppression of superconductivity by large magnetic fields. Here we use x-ray diffraction with access to large areas of reciprocal space to study the evolution of long- and short-range CDWs with in-plane strains and as a function of doping. This further allows us to precisely monitor in-situ the structural changes induced by uniaxial pressurization of the crystals for a precise strain estimation in measurements up to 0.85%-0.85 \% compression. Interestingly, we uncover direct evidence for a competition between long- and short-range CDWs and show that the long-range CDW modulation remains incommensurate at all investigated strains and temperatures, showing neither signs of discommensurations nor a pair-density wave component at λPDW=2λCDW\lambda_{\rm{PDW}} = 2\lambda_{\rm{CDW}} below TcT_c. We discuss the impact of structural disorder and the relationship of our findings to previous reports on nematicity in high-temperature superconducting cuprates. More generally, our results underscore the potential of strain tuning as a powerful tool for probing and manipulating competing orders in quantum materials.Comment: I. Vinograd and S. M. Souliou contributed equally to this wor

    The transcriptional coactivator TAZ regulates reciprocal differentiation of T(h)17 cells and T(reg) cells

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    自身免疫性疾病是一类机体对自身抗原发生免疫反应而导致自身多器官、组织受累的慢性炎症性疾病。目前大量研究表明机体内促炎症的TH17细胞和抑制炎症Treg细胞在类群数量和活化状态的失衡是造成自身免疫疾病的主要致病因素。陈兰芬教授和周大旺教授团队的前期研究发现小鼠中Hippo信号通路中激酶Mst1/2缺失导致免疫缺陷,机体易受病原体感染并伴随着严重自身免疫疾病。该研究揭示了Hippo 信号通路转录共激活因子TAZ在决定CD4+初始T细胞分化为促进炎症的TH17效应细胞和抑制免疫反应的Treg调节性细胞过程中发挥着关键作用,拓展了当前对于Hippo信号通路的相关研究内容。 陈兰芬,博士,厦门大学生命科学学院教授。【Abstraact】An imbalance in the lineages of immunosuppressive regulatory T cells (Treg cells) and the inflammatory TH17 subset of helper T cells leads to the development of autoimmune and/or inflammatory disease. Here we found that TAZ, a coactivator of TEAD transcription factors of Hippo signaling, was expressed under T H17 cell–inducing conditions and was required for TH17 differentiation and TH17 cell–mediated inflammatory diseases. TAZ was a critical co-activator of the TH17-defining transcription factor RORγt. In addition, TAZ attenuated Treg cell development by decreasing acetylation of the Treg cell master regulator Foxp3 mediated by the histone acetyltransferase Tip60, which targeted Foxp3 for proteasomal degradation. In contrast, under T regcell–skewing conditions, TEAD1 expression and sequestration of TAZ from the transcription factors RORγt and Foxp3 promoted Treg cell differentiation. Furthermore, deficiency in TAZ or overexpression of TEAD1 induced Treg cell differentiation, whereas expression of a transgene encoding TAZ or activation of TAZ directed TH17 cell differentiation. Our results demonstrate a pivotal role for TAZ in regulating the differentiation of Treg cells and TH17 cells.J. Avruch for comments on the manuscript.Supported by the National Basic Research Program (973) of China (2015CB910502 to L.C.), the National Natural Science Foundation of China (81422018 to L.C.; 31625010 and U1505224 to D.Z.; U1405225 and 81372617 to L.C.; J1310027 to D.Z.; 81472229 to L.H.; and 31600698 to J. Geng), the 111 Projects (B12001 and B06016), China's 1000 Young Talents Program (D.Z., and L.C.), the Fundamental Research Funds for the Central Universities of China-Xiamen University (20720160071 to D.Z. and 20720160054 to L.H.) and Major disease research projects of Xiamen (3502Z20149029 to L.C.)

    Contextualizing the Revised Patient Perception of Patient-Centeredness (Pppc-R) Scale in Primary Healthcare Settings: a Validity and Reliability Evaluation Study

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    BACKGROUND: An English version of the Patient Perception of Patient-Centeredness (PPPC) scale was recently revised, and it is necessary to test this instrument in different primary care populations. AIM: This study aimed to assess the validity and reliability of a Chinese version of the PPPC scale. DESIGN: A mixed method was used in this study. The Delphi method was used to collect qualitative and quantitative data to address the content validity of the PPPC scale by calculating the Content Validity Index, Content Validity Ratio, the adjusted Kappa, and the Item Impact Score. Confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) were used to assess the construct validity of the PPPC scale through a cross-sectional survey. The internal consistency was also assessed. SETTING/PARTICIPANTS: In the Delphi consultation, seven experts were consulted through a questionnaire sent by email. The cross-sectional survey interviewed 188 outpatients in Guangzhou city and 108 outpatients in Hohhot City from community health service centers or stations face-to-face. RESULTS: The 21 items in the scale were relevant to their component. The Item-level Content Validity Index for each item was higher than 0.79, and the average Scale-level content validity index was 0.97 in each evaluation round. The initial proposed 4-factor CFA model did not fit adequately. Still, we found a 3-factor solution based on our EFA model and the validation via the CFA model (model fit: [Formula: see text], P \u3c 0.001, RMSEA = 0.044, CFI = 0.981; factor loadings: 0.553 to 0.888). Cronbach\u27s α also indicated good internal consistency reliability: The overall Cronbach\u27s α was 0.922, and the Cronbach\u27s α for each factor was 0.851, 0.872, and 0.717, respectively. CONCLUSIONS: The Chinese version of the PPPC scale provides a valuable tool for evaluating patient-centered medical service quality

    High-yield single-step catalytic growth of graphene nanostripes by plasma enhanced chemical vapor deposition

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    We report a single-step growth process of graphene nanostripes (GNSPs) by adding certain substituted aromatics (e.g., 1,2-dichlorobenzene) as precursors during the plasma enhanced chemical vapor deposition (PECVD). Without any active heating and by using low plasma power (≤60 W), we are able to grow GNSPs vertically with high yields up to (13 ± 4) g/m^2 in 20 min. These GNSPs exhibit high aspect ratios (from 10:1 to >∼130:1) and typical widths from tens to hundreds of nanometers on various transition-metal substrates. The morphology, electronic properties and yields of the GNSPs can be controlled by the growth parameters (e.g., the species of seeding molecules, compositions and flow rates of the gases introduced into the plasma, plasma power, and the growth time). Studies of the Raman spectra, scanning electron microscopy images, ultraviolet photoelectron spectroscopy, transmission electron microscopy images, energy-dispersive x-ray spectroscopy and electrical conductivity of these GNSPs as functions of the growth parameters confirm high-quality GNSPs with electrical mobility ∼10^4 cm^2/V-s. These results together with residual gas analyzer spectra and optical emission spectroscopy taken during PECVD growth suggest the important roles of both substituted aromatics and hydrogen plasma in the rapid vertical growth of GNSPs with large aspect ratios
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