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Spectrally selective narrowband photodetection is critical for near-infrared (NIR) imaging applications, such as for communicationand night-vision utilities. It is a long-standing challenge for detectors based on silicon, to achieve narrowband photodetection without integrating any optical filters. Here, this work demonstrates a NIR nanograting Si/organic (PBDBT-DTBT:BTP-4F) heterojunction photodetector (PD), which for the first time obtains the full-width-at-half-maximum (FWHM) of only 26 nm and fast response of 74 µs at 895 nm. The response peak can be successfully tailored from 895 to 977 nm. The sharp and narrow response NIR peak is inherently attributed to the coherent overlapping between the NIR transmission spectrum of organic layer and diffraction enhanced absorption peak of patterned nanograting Si substrates. The finite difference time domain (FDTD) physics calculation confirms the resonant enhancement peaks, which is well consistent with the experiment results. Meanwhile, the relative characterization indicates that the introduction of the organic film can promote carrier transfer and charge collection, facilitating efficient photocurrent generation. This new device design strategy opens up a new window in developing low-cost sensitive NIR narrowband detection.
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Quantum dots (QDs) are exploited in visible light communication (VLC) due to their unique optical properties. However, it is still a challenge to conquer heating generation and photobleaching under prolonged illumination. In this paper, we proposed to utilize hexagonal boron nitride (h-BN) nanoplates to improve the thermal stability and photo stability of QDs and long-distance VLC data rate. After heating to 373â K and cooling to the initial temperature, photoluminescence (PL) emission intensity recovers to 62% of the original intensity and after 33 hours of illumination, PL emission intensity still maintains 80% of the initial intensity, while that of the bare QDs is only 34% and 53%, respectively. The QDs/h-BN composites perform a maximum achievable data rate of 98 Mbit/s by applying on-off keying (OOK) modulation, while the bare QDs are only 78 Mbps. In the process of extending the transmission distance from 0.3 m to 5 m, the QDs/h-BN composites exhibit superior luminosity corresponding to higher transmission data rates than bare QDs. Particularly, when the transmission distance reaches 5 m, the QDs/h-BN composites still show a clear eye diagram at a transmission rate of 50 Mbps while the eye diagram of bare QDs is indistinguishable at 25 Mbps. During 50 hours of continuous illumination, the QDs/h-BN composites keep a relatively stable bit error rate (BER) at 80 Mbps while that of QDs continuously increase, and the -3â dB bandwidth of QDs/h-BN composites keep around10 MHz while the bare QDs decrease from 12.6â MHz to 8.5â MHz. After illumination, the QDs/h-BN composites still indicate a clear eye diagram at a data rate of 50 Mbps while that of pure QDs is indistinguishable. Our results provide a feasible solution for realizing an enhanced transmission performance of QDs in longer-distance VLC.
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The experimental realization of multiple-input single-output (MISO) in visible light communication (VLC) has always been difficult due to dynamic channels, complex alignment, and limited capacity. We designed a quantum dot (QD) fluorescent concentrator combined with power domain multiplexing of a non-orthogonal multiple access (NOMA) scheme to provide an estimation-free MISO system. The system supports a large detection area of over 4â cm2 and a sum rate up to 120â Mbps over 2.3-m free space, providing a promising connection for the Internet of things (IoT). The concentrator was further implemented in an underwater environment under insufficient incident power. A record data rate of 120 Mbps has been achieved in a 1.5-m underwater MISO system, with a mean bit error rate of 3.24 × 10-3, which is below the forward error correction criterion.
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CONTEXT: Concanavalin A (Con A) exhibited multiple roles in cancer cells. However, the role of Con A in endothelial cells was not reported. OBJECTIVE: Our present study investigated the potential angiogenic role of Con A in endothelial cells and ischaemic hind-limb mice. MATERIALS AND METHODS: Human umbilical vein endothelial cells and Ea.hy926 cells were employed to determine the effect of Con A (0.3, 1, and 3 µg/mL) or vehicle on angiogenesis and cell proliferation with tube formation, ELISA, flow cytometry, EdU, and western blot. Hind-limb ischaemic mice were conducted to determine the pro-angiogenic effect of Con A (10 mg/kg) for 7 days. RESULTS: Con A promoted tube formation to about three-fold higher than the control group and increased the secretion of VEGFa, PDGFaa, and bFGF in the medium. The cell viability was promoted to 1.3-fold by Con A 3 µg/mL, and cell cycle progression of G0G1 phase was decreased from 77% in the vehicle group to 70% in Con A 3 µg/mL, G2M was promoted from 15 to 19%, and S-phase was from 7 to 10%. Con A significantly stimulated phosphorylation of Akt and ERK1/2 and expression of cyclin D1 and decreased the expression of p27. These effects of Con A were antagonised by the PI3K inhibitor LY294002 (10 µM) and MEK pathway antagonist PD98059 (10 µM). Moreover, Con A (10 mg/kg) exhibited a repair effect in ischaemic hind-limb mice. DISCUSSION AND CONCLUSIONS: This study will provide a new option for treating ischaemic disease by local injection with Con A.
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Inductores de la Angiogénesis/farmacología , Proliferación Celular/efectos de los fármacos , Concanavalina A/farmacología , Neovascularización Fisiológica/efectos de los fármacos , Inductores de la Angiogénesis/administración & dosificación , Animales , Supervivencia Celular/efectos de los fármacos , Cromonas/farmacología , Concanavalina A/administración & dosificación , Ciclina D1/metabolismo , Relación Dosis-Respuesta a Droga , Flavonoides/farmacología , Miembro Posterior , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Isquemia/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Morfolinas/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
Oxidative stress has a considerable influence on endothelial cell dysfunction and atherosclerosis. Acacetin, an anti-inflammatory and antiarrhythmic, is frequently used in the treatment of myocarditis, albeit its role in managing atherosclerosis is currently unclear. Thus, we evaluated the regulatory effects of acacetin in maintaining endothelial cell function and further investigated whether the flavonoid could attenuate atherosclerosis in apolipoprotein E deficiency (apoE-/- ) mice. Different concentrations of acacetin were tested on EA.hy926 cells, either induced or non-induced by human oxidized low-density lipoprotein (oxLDL), to clarify its influence on cell viability, cellular reactive oxidative stress (ROS) level, apoptotic ratios and other regulatory effects. In vivo, apoE-/- mice were fed either a Western diet or a chow diet. Acacetin pro-drug (15 mg/kg) was injected subcutaneously two times a day for 12 weeks. The effects of acacetin on the atherosclerotic process, plasma inflammatory factors and lipid metabolism were also investigated. Acacetin significantly increased EA.hy926 cell viability by reducing the ratios of apoptotic and necrotic cells at 3 µmol/L. Moreover, 3 µmol/L acacetin clearly decreased ROS levels and enhanced reductase protein expression through MsrA and Nrf2 pathway through phosphorylation of Nrf2 and degradation of Keap1. In vivo, acacetin treatment remarkably attenuated atherosclerosis by increasing reductase levels in circulation and aortic roots, decreasing plasma inflammatory factor levels as well as accelerating lipid metabolism in Western diet-fed apoE-/- mice. Our findings demonstrate the anti-oxidative and anti-atherosclerotic effects of acacetin, in turn suggesting its potential therapeutic value in atherosclerotic-related cardiovascular diseases (CVD).
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Antioxidantes/metabolismo , Apolipoproteínas E/metabolismo , Aterosclerosis/metabolismo , Células Endoteliales/metabolismo , Flavonas/uso terapéutico , Factor 2 Relacionado con NF-E2/metabolismo , Animales , Apolipoproteínas E/genética , Línea Celular , Supervivencia Celular/genética , Supervivencia Celular/fisiología , Citometría de Flujo , Humanos , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Ratones , Ratones Endogámicos C57BL , Factor 2 Relacionado con NF-E2/genética , Estrés Oxidativo/genética , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Diamide compounds were identified as potent DGAT1 inhibitors in vitro, but their poor molecular properties resulted in low oral bioavailability, both systemically and to DGAT1 in the enterocytes of the small intestine, resulting in a lack of efficacy in vivo. Replacing an N-alkyl group on the diamide with an N-aryl group was found to be an effective strategy to confer oral bioavailability and oral efficacy in this lipophilic diamide class of inhibitors.
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Diacilglicerol O-Acetiltransferasa/antagonistas & inhibidores , Diamida/química , Inhibidores Enzimáticos/química , Animales , Línea Celular Tumoral , Diacilglicerol O-Acetiltransferasa/metabolismo , Diamida/síntesis química , Diamida/farmacocinética , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacocinética , Semivida , Humanos , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
Due to the unique and excellent optical performance and promising prospect for various photonics applications, cavity-enhanced superfluorescence (CESF) in perovskite quantum dot assembled superstructures has garnered wide attention. However, the stringent requirements and high threshold for achieving CESF limit its further development and application. The high threshold of CESF in quantum dot superstructures is mainly attributed to the low radiation recombination rate of the quantum dot and the unsatisfactory light field limiting the ability of the assembled superstructures originating from low controllability of self-assembly. Herein, we propose a strategy to reduce the threshold of CESF in quantum dot superstructure microcavities from two aspects: facet engineering optimization of quantum dot blocks and controllability improvement of the assembly method. We introduce dodecahedral quantum dots with lower nonradiative recombination, substituting frequently used cubic quantum dots as assembly blocks. Besides, we adopt the micro-emulsion droplet assembly method to obtain spherical perovskite quantum dot superparticles with high packing factors and orderly internal arrangements, which are more controllable and efficient than the conventional solvent-drying methods. Based on the dodecahedral quantum dot superparticles, we realized low-threshold CESF (Pth = 15.6 µJ cm-2). Our work provides a practical and scalable avenue for realizing low threshold CESF in quantum dot assembled superstructure systems.
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Benefiting from the high modulation bandwidth (BW), low energy consumption and excellent optical performance, lead halide perovskite has attracted wide attention in visible light communication (VLC). However, the ion migration which results in mobile point defects in perovskite structures is recognized as a crucial key factor inducing the performance degradation. Here, the influence of ion migration in perovskite devices on the performance of VLC was systematically studied. The ion migration process is realized by mixing CsPbBr3 and CsPbI3 quantum dots, during which, the performance of the VLC system is reduced, but it can return to its initial state after stabilization. The on-off keying (OOK) modulation scheme of the perovskite light-emitting diode (LED) device was carried out, achieving a data rate of 90 Mbps.
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BACKGROUND: Protection of cardiac function following myocardial infarction was largely enhanced by bradykinin-pretreated cardiac-specific c-kit+ (BK-c-kit+) cells, even without significant engraftment, indicating that paracrine actions of BK-c-kit+ cells play a pivotal role in angiogenesis. Nevertheless, the active components of the paracrine actions of BK-c-kit+ cells and the underlying mechanisms remain unknown. This study aimed to define the active components of exosomes from BK-c-kit+ cells and elucidate their underlying protective mechanisms. METHODS: Matrigel tube formation assay, cell cycle, and mobility in human umbilical vein endothelial cells (HUVECs) and hindlimb ischemia (HLI) in mice were applied to determine the angiogenic effect of condition medium (CM) and exosomes. Proteome profiler, microRNA sponge, Due-luciferase assay, microRNA-sequencing, qRT-PCR, and Western blot were used to determine the underlying mechanism of the angiogenic effect of exosomes from BK-c-kit+. RESULTS: As a result, BK-c-kit+ CM and exosomes promoted tube formation in HUVECs and the repair of HLI in mice. Angiogenesis-related proteomic profiling and microRNA sequencing revealed highly enriched miR-3059-5p as a key angiogenic component of BK-c-kit+ exosomes. Meanwhile, loss- and gain-of-function experiments revealed that the promotion of angiogenesis by miR-3059-5p was mainly through suppression of TNFSF15-inhibited effects on vascular tube formation, cell proliferation and cell migration. Moreover, enhanced angiogenesis of miR-3059-5p-inhibited TNFSF15 has been associated with Akt/Erk1/2/Smad2/3-modulated signaling pathway. CONCLUSION: Our results demonstrated a novel finding that BK-c-kit+ cells enrich exosomal miR-3059-5p to suppress TNFSF15 and promote angiogenesis against hindlimb ischemia in mice.
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Bradiquinina , MicroARNs , Humanos , Ratones , Animales , Bradiquinina/metabolismo , Proteómica , Neovascularización Fisiológica/genética , MicroARNs/genética , MicroARNs/metabolismo , Isquemia/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Miembro Posterior/metabolismo , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/metabolismoRESUMEN
Parkin, an E3 ubiquitin ligase, plays an essential role in mitophagy. Emerging evidence indicates that mitophagy is involved in various processes closely related to immune diseases, including inflammatory bowel diseases (IBD). Here, the authors show that Parkin increases the occurrence of colitis and severe inflammation. Deletion of Parkin resulted in marked reductions in colonic inflammation and exhibited high resistance to DSS-induced colitis. Mechanism investigation indicated that Parkin interacts with Vitamin D receptors (VDR), a critical inhibitory regulator in IBD. Parkin promotes VDR degradation via the p62-related autophagy-lysosome pathway. Comparison of colitis in Parkin-/- and Parkin-/-Vdr-/- mice showed that the protective effect of Parkin deletion against colitis was abolished by VDR deletion. The result suggests that the regulatory effect of Parkin in colitis is a VDR-dependent pathway. Our research provides a new role of Parkin in colitis by downregulating VDR, which provides a potential strategy for treating IBD.
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Colitis , Enfermedades Inflamatorias del Intestino , Ratones , Animales , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Regulación hacia Abajo , Colitis/genética , Colitis/inducido químicamente , Enfermedades Inflamatorias del Intestino/metabolismo , Inflamación , Autofagia/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Metamaterial absorbers (MMAs) offer a novel and flexible method to realize perfect absorption in specific frequencies, especially in the THz range. Despite the exotic abilities to manipulate light, most previously reported MMAs still suffer from limited bandwidth and tunability. Here we present a thermally switchable terahertz (THz) metasurface that exhibits ultra-broadband absorption and high-transmission characteristics at different ambient temperatures. Our simulations demonstrate that at room temperature the structure is highly transparent. When the ambient temperature reaches 358 K, the proposed design exhibits an ultra-broadband absorption from 0.398 to 1.356 THz with the absorptivity maintaining above 90% and the relative absorption bandwidth reaches up to 109.2%. The structure is demonstrated to be insensitive to the incident angle. Moreover, the bandwidth of such a structure can easily be expanded or reduced by cascading or removing the rings, providing high scalability in practical applications. Such a thermally switchable THz metasurface may have potential applications in various fields, such as optical switching, THz imaging, modulating and filtering.
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Semiconductor quantum dots (QDs) are a promising luminescent phosphor for next-generation lightings and displays. In particular, QD-based white light-emitting diodes (WLEDs) are considered to be the candidate light sources with the most potential for application in displays. In this work, we synthesized quaternary/ternary core/shell alloyed CdZnSeS/ZnSeS QDs with high bright emission intensity. The QDs show good thermal stability by performing high temperature-dependent experiments that range from 295 to 433 K. Finally, the WLED based on the CdZnSeS/ZnSeS QDs exhibits a luminous efficiency (LE) of 28.14 lm/W, an external quantum efficiency (EQE) of 14.86%, and a warm bright sunlight close to the spectrum of daylight (Commission Internationale de l'éclairage (CIE) coordinates 0.305, 0.371). Moreover, the photoluminescence (PL) intensity, LE, EQE, and correlated color temperature (CCT) of as-prepared QD WLED remained relatively stable with only slight changes in the luminescence stability experiment.
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Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates plasma low-density lipoprotein cholesterol (LDL-C) levels by promoting hepatic LDL receptor (LDLR) degradation. Therapeutic antibodies that disrupt PCSK9-LDLR binding reduce LDL-C concentrations and cardiovascular disease risk. The epidermal growth factor precursor homology domain A (EGF-A) of the LDLR serves as a primary contact with PCSK9 via a flat interface, presenting a challenge for identifying small molecule PCSK9-LDLR disruptors. We employ an affinity-based screen of 1013in vitro-translated macrocyclic peptides to identify high-affinity PCSK9 ligands that utilize a unique, induced-fit pocket and partially disrupt the PCSK9-LDLR interaction. Structure-based design led to molecules with enhanced function and pharmacokinetic properties (e.g., 13PCSK9i). In mice, 13PCSK9i reduces plasma cholesterol levels and increases hepatic LDLR density in a dose-dependent manner. 13PCSK9i functions by a unique, allosteric mechanism and is the smallest molecule identified to date with in vivo PCSK9-LDLR disruptor function.
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Péptidos/farmacología , Proproteína Convertasa 9/metabolismo , Receptores de LDL/antagonistas & inhibidores , Animales , Relación Dosis-Respuesta a Droga , Células Hep G2 , Humanos , Ligandos , Masculino , Ratones , Ratones Endogámicos C57BL , Péptidos/síntesis química , Péptidos/química , Conformación Proteica , Receptores de LDL/metabolismoRESUMEN
BACKGROUND: Previous studies have demonstrated that human cardiac c-Kit+ progenitor cells (hCPCs) can effectively improve ischemic heart disease. However, the major challenge in applying hCPCs to clinical therapy is the low survival rate of graft hCPCs in the host heart, which limited the benefit of transplanted hCPCs. Bradykinin (BK) is a principal active agent of the tissue kinin-kallikrein system. Our previous studies have highlighted that BK mediated the growth and migration of CPCs by regulating Ca2+ influx. However, the protective effect of BK on CPCs, improvement in the survival rate of BK-pretreated hCPCs in the infarcted heart, and the related mechanism remain elusive. METHODS: HCPCs were treated with H2O2 to induce cell apoptosis and autophagy, and different concentration of BK was applied to rescue the H2O2-induced injury detected by MTT assay, TUNEL staining, flow cytometry, western blotting, and mitoSOX assays. The role of autophagy in the anti-apoptotic effect of BK was chemically activated or inhibited using the autophagy inducer, rapamycin, or the inhibitor, 3-methyladenine (3-MA). To explore the protective effect of BK on hCPCs, 3-MA or BK-pretreated hCPCs were transplanted into the myocardial infarcted rats. An echocardiogram was used to determine cardiac function, H&E and Masson staining were employed to assess pathological characteristics, HLA gene expression was quantified by qRT-PCR, and immunostaining was applied to examine neovascularization using confocal microscopy. RESULTS: The in vitro results showed that BK suppressed H2O2-induced hCPCs apoptosis and ROS production in a concentration-dependent manner by promoting pAkt and Bcl-2 expression and reducing cleaved caspase 3 and Bax expression. Moreover, BK restrained the H2O2-induced cell autophagy by decreasing LC3II/I, Beclin1, and ATG5 expression and increasing P62 expression. In the in vivo experiment, the transplanted BK- or 3-MA-treated hCPCs were found to be more effectively improved cardiac function by decreasing cardiomyocyte apoptosis, inflammatory infiltration, and myocardial fibrosis, and promoting neovascularization in the infarcted heart, compared to untreated-hCPCs or c-kit- cardiomyocytes (CPC- cells). CONCLUSIONS: Our present study established a new method to rescue transplanted hCPCs in the infarcted cardiac area via regulating cell apoptosis and autophagy of hCPCs by pretreatment with BK, providing a new therapeutic option for heart failure.
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Bradiquinina , Peróxido de Hidrógeno , Animales , Apoptosis , Autofagia , Bradiquinina/farmacología , Células Cultivadas , Miocitos Cardíacos , Ratas , Células MadreRESUMEN
MiR-30a-5p plays an important role in various cardiovascular diseases, but its effect in atherosclerosis has not been reported. Apolipoprotein E-deficient (Apo E-/-) mice were used to investigate the role of miR-30a-5p in atherosclerosis, and the underlying mechanism was investigated in vivo and in vitro. The fluorescence in situ hybridization test revealed that miR-30a-5p was expressed in Apo E-/- mice lesions. Nevertheless, in RAW264.7 macrophages, the expression of miR-30a-5p was reduced by lipopolysaccharide (LPS) or oxidized low-density lipoprotein. MiR-30a-5p-ago-treated Apo E-/- mice significantly reduced lesion areas in the aorta and aortic root, reduced levels of lipoprotein and pro-inflammatory cytokines, and increased levels of anti-inflammatory cytokines. The ratio of M1/M2 macrophages was decreased in miR-30a-5p-ago-treated Apo E-/- mice and LPS-treated RAW264.7 macrophages by the regulation of Smad-1/2 phosphorylation. MiR-30a-5p reduced lipid uptake in oxidized low-density lipoprotein-treated macrophages by regulating the expression of PPAR-γ, ABCA1, ABCG1, LDLR, and PCSK9. Ubiquitinated ligase NEDD4L was identified as a target of miR-30a-5p. Interestingly, knockdown of NEDD4L decreased the M1/M2 ratio and oxidized low-density lipoprotein uptake in macrophages by inhibiting the ubiquitination of PPAR-γ and phosphorylation of Smad-1/2 and regulating ABCA1, ABCG1, LDLR, and PCSK9. We demonstrated a novel effect and mechanism of miR-30a-5p in atherosclerosis.
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Metamaterial absorbers (MMAs) with dynamic tuning features have attracted great attention recently, but most realizations to date have suffered from a decay in absorptivity as the working frequency shifts. Here, thermally tunable multi-band and ultra-broadband MMAs based on vanadium dioxide (VO2) are proposed, with nearly no reduction in absorption during the tuning process. Simulations demonstrated that the proposed design can be switched between two independently designable multi-band frequency ranges, with the absorptivity being maintained above 99.8%. Moreover, via designing multiple adjacent absorption spectra, an ultra-broadband switchable MMA that maintains high absorptivity during the tuning process is also demonstrated. Raising the ambient temperature from 298 K to 358 K, the broadband absorptive range shifts from 1.194-2.325 THz to 0.398-1.356 THz, while the absorptivity remains above 90%. This method has potential for THz communication, smart filtering, detecting, imaging, and so forth.
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Although cuprous phosphide (Cu3P) has been widely studied and applied in other fields, its photoluminescence (PL) properties are rarely investigated. Herein, we report that Cu3P can emit near-infrared light at 750 nm. We show that the annealing and the presence of cuprous oxide can enhance the PL emission. The mechanism of the PL enhancement is the improvement of crystal quality and the formation of a space charge region. Our results provide a reference for improving the PL properties of p-type semiconductors.
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Advances in the design of permeable peptides and in the synthesis of large arrays of macrocyclic peptides with diverse amino acids have evolved on parallel but independent tracks. Less precedent combines their respective attributes, thereby limiting the potential to identify permeable peptide ligands for key targets. Herein, we present novel 6-, 7-, and 8-mer cyclic peptides (MW 774-1076 g·mol-1) with passive permeability and oral exposure that feature the amino acids and thioether ring-closing common to large array formats, including DNA- and RNA-templated synthesis. Each oral peptide herein, selected from virtual libraries of partially N-methylated peptides using in silico methods, reflects the subset consistent with low energy conformations, low desolvation penalties, and passive permeability. We envision that, by retaining the backbone N-methylation pattern and consequent bias toward permeability, one can generate large peptide arrays with sufficient side chain diversity to identify permeability-biased ligands to a variety of protein targets.
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Péptidos Cíclicos/farmacología , Sulfuros/farmacología , Administración Oral , Animales , Células CACO-2 , Permeabilidad de la Membrana Celular , Perros , Humanos , Células de Riñón Canino Madin Darby , Masculino , Metilación , Estructura Molecular , Péptidos Cíclicos/administración & dosificación , Péptidos Cíclicos/síntesis química , Péptidos Cíclicos/farmacocinética , Conformación Proteica , Ratas Sprague-Dawley , Bibliotecas de Moléculas Pequeñas/administración & dosificación , Bibliotecas de Moléculas Pequeñas/síntesis química , Bibliotecas de Moléculas Pequeñas/farmacocinética , Bibliotecas de Moléculas Pequeñas/farmacología , Sulfuros/administración & dosificación , Sulfuros/síntesis química , Sulfuros/farmacocinética , TermodinámicaRESUMEN
Differentiation potency of human dental pulp cells (hDPCs) is essential for dentin regeneration. DNA methylation is one of the major epigenetic mechanisms and is suggested to involve in differentiation of hDPCs, the machinery of which includes DNA methyltransferase enzymes (DNMTs) and methyl-CpG-binding domain proteins (MBDs). Our previous study has found that melatonin (MT) promoted hDPC differentiation, but its mechanism remains elusive. We aimed to investigate the role of DNA methylation in the promotion of MT to differentiation of hDPCs in vitro. hDPCs were cultured in basal growth medium (CO) or odontogenic medium (OM) exposed to MT at different concentrations (0, 10-12, 10-10, 10-8, 10-6, 10-4 M). The cell growth was analyzed using Cell Counting Kit-8 assay, and mineralized tissue formation was measured using Alizarin red staining. The expression of the 10 genes (DNMT1, DNMT3A, DNMT3B, MBD1-6, MeCP2) was determined using real-time qPCR and western blotting. The abundance of MeCP2 in the nuclei was evaluated using immunofluorescence analysis. Global methylation level was tested using ELISA. We found that mineralized tissue formation significantly increased in OM with MT at 10-4 M, while the levels of MeCP2 and global DNA methylation level declined. The expression of MBD1, MBD3, and MBD4 significantly increased in OM alone, and the expession of DNMT1 and MBD2 was decreased. These results indicate that MT promotes odontogenic differentiation of hDPCs in vitro by regulating the levels of DNMT1, MeCP2, and global DNA methylation, suggesting that MT-induced DNA methylation machinery may play an important role in tooth regeneration.
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Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Metilación de ADN/efectos de los fármacos , Metilación de ADN/genética , Pulpa Dental/citología , Melatonina/farmacología , Odontogénesis/efectos de los fármacos , Odontogénesis/genética , Adolescente , Adulto , Western Blotting , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Células Cultivadas , ADN (Citosina-5-)-Metiltransferasa 1/genética , ADN (Citosina-5-)-Metiltransferasa 1/metabolismo , ADN (Citosina-5-)-Metiltransferasas/genética , ADN (Citosina-5-)-Metiltransferasas/metabolismo , ADN Metiltransferasa 3A , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Masculino , Proteína 2 de Unión a Metil-CpG/genética , Proteína 2 de Unión a Metil-CpG/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Adulto Joven , ADN Metiltransferasa 3BRESUMEN
N-Acetyl-5-methoxytryptamine (melatonin, MT) at pharmacological concentrations promotes the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells; however, its role at physiological concentrations (1 pM-10 nM) remains unclear. We explored the effects of 1 pM-1 µM MT on the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and its underlying mitochondrial dynamics-mediated mechanisms. T he PDLSC phenotype was detected by flow cytometry and evaluated for three-line differentiation. Alkaline phosphatase activity assay and Alizarin red staining were used to evaluate osteogenic differentiation. Osteogenesis-related gene and protein expression levels were measured by quantitative reverse transcription -polymerase chain reaction and western blotting. Mitochondrial function assays were performed using reactive oxygen species, ATP and NAD+/NADH kits and molecular mechanisms of mitochondrial dynamics-related proteins were assessed by western blotting. Our results have shown that physiological MT concentrations induced differentiation of hPDLSCs and down-regulated osteopontin (OPN) and osteocalcin (OCN) expression levels, which were restored or even up-regulated by 1 µM MT (lowest pharmacological concentration). Compared to the osteogenic induction alone, this treatment decreased the intracellular ATP content, whereas the intracellular reactive oxygen species level and NAD+/NADH ratio were increased. Mitochondrial function- and dynamics-related protein expression levels were consistent with those of osteogenic genes following osteogenic induction and MT treatment of hPDLSCs at various physiological concentrations. Physiological MT concentrations inhibited the osteogenic differentiation of hPDLSCs and simultaneously altered mitochondrial function. These findings provide insights into the stem cell tissue engineering and functions of MT.