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1.
Circ Heart Fail ; 17(3): e010569, 2024 03.
Article in English | MEDLINE | ID: mdl-38410978

ABSTRACT

BACKGROUND: Exercise training can promote cardiac rehabilitation, thereby reducing cardiovascular disease mortality and hospitalization rates. MicroRNAs (miRs) are closely related to heart disease, among which miR-574-3p plays an important role in myocardial remodeling, but its role in exercise-mediated cardioprotection is still unclear. METHODS: A mouse myocardial hypertrophy model was established by transverse aortic coarctation, and a 4-week swimming exercise training was performed 1 week after the operation. After swimming training, echocardiography was used to evaluate cardiac function in mice, and histopathologic staining was used to detect cardiac hypertrophy, myocardial fibrosis, and cardiac inflammation. Quantitative real-time polymerase chain reaction was used to detect the expression levels of miR-574-3p and cardiac hypertrophy markers. Western blotting detected the IL-6 (interleukin-6)/JAK/STAT inflammatory signaling pathway. RESULTS: Echocardiography and histochemical staining found that aerobic exercise significantly improved pressure overload-induced myocardial hypertrophy (n=6), myocardial interstitial fibrosis (n=6), and cardiac inflammation (n=6). Quantitative real-time polymerase chain reaction detection showed that aerobic exercise upregulated the expression level of miR-574-3p (n=6). After specific knockdown of miR-574-3p in mouse hearts with adeno-associated virus 9 using cardiac troponin T promoter, we found that the protective effect of exercise training on the heart was significantly reversed. Echocardiography and histopathologic staining showed that inhibiting the expression of miR-574-3p could partially block the effects of aerobic exercise on cardiac function (n=6), cardiomyocyte cross-sectional area (n=6), and myocardial fibrosis (n=6). Western blotting and immunohistochemical staining showed that the inhibitory effects of aerobic exercise on the IL-6/JAK/STAT pathway and cardiac inflammation were partially abolished after miR-574-3p knockdown. Furthermore, we also found that miR-574-3p exerts cardioprotective effects in cardiomyocytes by targeting IL-6 (n=3). CONCLUSIONS: Aerobic exercise protects cardiac hypertrophy and inflammation induced by pressure overload by upregulating miR-574-3p and inhibiting the IL-6/JAK/STAT pathway.


Subject(s)
Heart Failure , MicroRNAs , Myocarditis , Mice , Animals , Interleukin-6/metabolism , Janus Kinases/metabolism , Heart Failure/metabolism , Signal Transduction , STAT Transcription Factors/metabolism , Myocytes, Cardiac/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Cardiomegaly/pathology , Myocarditis/genetics , Myocarditis/prevention & control , Inflammation/pathology , Disease Models, Animal , Fibrosis
2.
J Phys Chem Lett ; 15(2): 556-564, 2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38198134

ABSTRACT

The human brain efficiently processes only a fraction of visual information, a phenomenon termed attentional control, resulting in energy savings and heightened adaptability. Translating this mechanism into artificial visual neurons holds promise for constructing energy-efficient, bioinspired visual systems. Here, we propose a self-rectifying artificial visual neuron (SEVN) based on a NiO/Ga2O3 bipolar heterojunction with attentional control on patterns with a target color. The device exhibits short-term potentiation (STP) with quantum point contact (QPC) traits at low bias and transitions to long-term potentiation (LTP) at high bias, particularly facilitated by electron capture in deep defects upon ultraviolet (UV) exposure. With the utilization of two wavelengths of light upon the target and interference part of CAPTCHA to simulate top-down attentional control, the recognition accuracy is enhanced from 74 to 84%. These findings have the potential to augment the visual capability of neuromorphic systems with implications for diverse applications, including cybersecurity, healthcare, and machine vision.


Subject(s)
Brain , Synapses , Humans , Synapses/physiology , Neurons
3.
Acta Pharmacol Sin ; 45(2): 312-326, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37833535

ABSTRACT

Apoptosis plays a critical role in the development of heart failure, and sphingosylphosphorylcholine (SPC) is a bioactive sphingolipid naturally occurring in blood plasma. Some studies have shown that SPC inhibits hypoxia-induced apoptosis in myofibroblasts, the crucial non-muscle cells in the heart. Calmodulin (CaM) is a known SPC receptor. In this study we investigated the role of CaM in cardiomyocyte apoptosis in heart failure and the associated signaling pathways. Pressure overload was induced in mice by trans-aortic constriction (TAC) surgery. TAC mice were administered SPC (10 µM·kg-1·d-1) for 4 weeks post-surgery. We showed that SPC administration significantly improved survival rate and cardiac hypertrophy, and inhibited cardiac fibrosis in TAC mice. In neonatal mouse cardiomyocytes, treatment with SPC (10 µM) significantly inhibited Ang II-induced cardiomyocyte hypertrophy, fibroblast-to-myofibroblast transition and cell apoptosis accompanied by reduced Bax and phosphorylation levels of CaM, JNK and p38, as well as upregulated Bcl-2, a cardiomyocyte-protective protein. Thapsigargin (TG) could enhance CaM functions by increasing Ca2+ levels in cytoplasm. TG (3 µM) annulled the protective effect of SPC against Ang II-induced cardiomyocyte apoptosis. Furthermore, we demonstrated that SPC-mediated inhibition of cardiomyocyte apoptosis involved the regulation of p38 and JNK phosphorylation, which was downstream of CaM. These results offer new evidence for SPC regulation of cardiomyocyte apoptosis, potentially providing a new therapeutic target for cardiac remodeling following stress overload.


Subject(s)
Calmodulin , Heart Failure , Phosphorylcholine/analogs & derivatives , Sphingosine/analogs & derivatives , Mice , Animals , Calmodulin/metabolism , Calmodulin/pharmacology , Calmodulin/therapeutic use , Cardiomegaly/drug therapy , Cardiomegaly/metabolism , Heart Failure/metabolism , Myocytes, Cardiac , Signal Transduction , Ventricular Remodeling , Mice, Inbred C57BL
4.
Nat Commun ; 14(1): 4459, 2023 Jul 25.
Article in English | MEDLINE | ID: mdl-37491528

ABSTRACT

Avalanche and surge robustness involve fundamental carrier dynamics under high electric field and current density. They are also prerequisites of any power device to survive common overvoltage and overcurrent stresses in power electronics applications such as electric vehicles, electricity grids, and renewable energy processing. Despite tremendous efforts to develop the next-generation power devices using emerging ultra-wide bandgap semiconductors, the lack of effective bipolar doping has been a daunting obstacle for achieving the necessary robustness in these devices. Here we report avalanche and surge robustness in a heterojunction formed between the ultra-wide bandgap n-type gallium oxide and the wide-bandgap p-type nickel oxide. Under 1500 V reverse bias, impact ionization initiates in gallium oxide, and the staggered band alignment favors efficient hole removal, enabling a high avalanche current over 50 A. Under forward bias, bipolar conductivity modulation enables the junction to survive over 50 A surge current. Moreover, the asymmetric carrier lifetime makes the high-level carrier injection dominant in nickel oxide, enabling a fast reverse recovery within 15 ns. This heterojunction breaks the fundamental trade-off between robustness and switching speed in conventional homojunctions and removes a key hurdle to advance ultra-wide bandgap semiconductor devices for power industrial applications.

5.
Biochim Biophys Acta Mol Basis Dis ; 1869(8): 166813, 2023 12.
Article in English | MEDLINE | ID: mdl-37488049

ABSTRACT

Ubiquitin-specific protease 22 (USP22) is a member of the ubiquitin specific protease family (ubiquitin-specific protease, USPs), the largest subfamily of deubiquitinating enzymes, and plays an important role in the treatment of tumors. USP22 is also expressed in the heart. However, the role of USP22 in heart disease remains unclear. In this study, we found that USP22 was elevated in hypertrophic mouse hearts and in angiotensin II (Ang II)-induced cardiomyocytes. The inhibition of USP22 expression with adenovirus significantly rescued hypertrophic phenotype and cardiac dysfunction induced by pressure overloaded. Consistent with in vivo study, silencing by USP22 shRNA expression in vitro had similar results. Molecular analysis revealed that transforming growth factor-ß-activating protein 1 (TAK1)-(JNK1/2)/P38 signaling pathway and HIF-1α was activated in the Ang II-induced hypertrophic cardiomyocytes, whereas HIF-1α expression was decreased after the inhibition of USP22. Inhibition of HIF-1α expression reduces TAK1 expression. Co-immunoprecipitation and ubiquitination studies revealed the regulatory mechanism between USP22 and HIF1α.Under hypertrophic stress conditions, USP22 enhances the stability of HIF-1α through its deubiquitination activity, which further activates the TAK1-(JNK1/2)/P38 signaling pathway to lead to cardiac hypertrophy. Inhibition of HIF-1α expression further potentiates the in vivo pathological effects caused by USP22 deficiency. In summary, this study suggests that USP22, through HIF-1α-TAK1-(JNK1/2)/P38 signaling pathway, may be potential targets for inhibiting pathological cardiac hypertrophy induced by pressure overload.


Subject(s)
Cardiomegaly , MAP Kinase Kinase Kinases , Animals , Mice , Cardiomegaly/metabolism , MAP Kinase Kinase Kinases/genetics , Myocytes, Cardiac/metabolism , Signal Transduction , Ubiquitin-Specific Proteases/metabolism , Ubiquitin-Specific Proteases/pharmacology
6.
Opt Lett ; 48(2): 247-250, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36638429

ABSTRACT

The authors demonstrate the enhanced light output from 275-nm AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) structures via the in-plane modulation of shallow photonic crystal (PC) patterns that were fabricated on the p-AlGaN contact layer surface. The employed PC lattice constants are in the range of 270-780 nm, much larger than the fundamental Bragg order lattice constant (∼95 nm). As compared to the unpatterned sample, the intensity of the top (or bottom) emission can be enhanced by up to 331% (or 246%), attributed to the high-order coherent diffraction of the internal trapped light and also the Purcell enhancement of spontaneous emission. The findings in this Letter suggest an easier way for the realization of more energy-efficient DUV LEDs which offer the advantage of high emission for various applications in disinfection and sterilization.

7.
Acta Pharmacol Sin ; 44(7): 1366-1379, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36721009

ABSTRACT

Previous studies show that notoginsenoside R1 (NG-R1), a novel saponin isolated from Panax notoginseng, protects kidney, intestine, lung, brain and heart from ischemia-reperfusion injury. In this study we investigated the cardioprotective mechanisms of NG-R1 in myocardial ischemia/reperfusion (MI/R) injury in vivo and in vitro. MI/R injury was induced in mice by occluding the left anterior descending coronary artery for 30 min followed by 4 h reperfusion. The mice were treated with NG-R1 (25 mg/kg, i.p.) every 2 h for 3 times starting 30 min prior to ischemic surgery. We showed that NG-R1 administration significantly decreased the myocardial infarction area, alleviated myocardial cell damage and improved cardiac function in MI/R mice. In murine neonatal cardiomyocytes (CMs) subjected to hypoxia/reoxygenation (H/R) in vitro, pretreatment with NG-R1 (25 µM) significantly inhibited apoptosis. We revealed that NG-R1 suppressed the phosphorylation of transforming growth factor ß-activated protein kinase 1 (TAK1), JNK and p38 in vivo and in vitro. Pretreatment with JNK agonist anisomycin or p38 agonist P79350 partially abolished the protective effects of NG-R1 in vivo and in vitro. Knockdown of TAK1 greatly ameliorated H/R-induced apoptosis of CMs, and NG-R1 pretreatment did not provide further protection in TAK1-silenced CMs under H/R injury. Overexpression of TAK1 abolished the anti-apoptotic effect of NG-R1 and diminished the inhibition of NG-R1 on JNK/p38 signaling in MI/R mice as well as in H/R-treated CMs. Collectively, NG-R1 alleviates MI/R injury by suppressing the activity of TAK1, subsequently inhibiting JNK/p38 signaling and attenuating cardiomyocyte apoptosis.


Subject(s)
Ginsenosides , Myocardial Reperfusion Injury , Mice , Animals , Myocardial Reperfusion Injury/drug therapy , Myocardial Reperfusion Injury/prevention & control , Myocardial Reperfusion Injury/metabolism , Ginsenosides/pharmacology , Ginsenosides/therapeutic use , Ginsenosides/metabolism , Myocardium , Myocytes, Cardiac , Apoptosis
8.
Can J Cardiol ; 39(1): 73-86, 2023 01.
Article in English | MEDLINE | ID: mdl-36240973

ABSTRACT

BACKGROUND: Ischemic cardiomyopathy (ICM) is associated with electrical and structural remodelling, leading to arrhythmias. Caveolin-1 (Cav1) is a membrane protein involved in the pathogenesis of ischemic injury. Cav1 deficiency has been associated with arrhythmogenicity. The current study aimed to determine how Cav1 overexpression inhibits arrhythmias and cardiac remodelling in ICM. METHODS: ICM was modelled using left anterior descending (LAD) artery ligation for 4 weeks. Cardiac-specific Cav1 overexpression in ICM on arrhythmias, excitation-contraction coupling, and cardiac remodelling were investigated using the intramyocardial injection of an adeno-associated virus serotype 9 (AAV-9) system, carrying a specific sequence expressing Cav1 (AAVCav1) under the cardiac troponin T (cTnT) promoter. RESULTS: Cav1 overexpression decreased susceptibility to arrhythmias by upregulating gap junction connexin 43 (CX43) and reducing spontaneous irregular proarrhythmogenic Ca2+ waves in ventricular cardiomyocytes. It also alleviated ischemic injury-induced contractility weakness by improving Ca2+ cycling through normalizing Ca2+-handling protein levels and improving Ca2+ homeostasis. Masson stain and immunoblotting revealed that the deposition of excessive fibrosis was attenuated by Cav1 overexpression, inhibiting the transforming growth factor-ß (TGF-ß)/Smad2 signalling pathway. Coimmunoprecipitation assays demonstrated that the interaction between Cav1 and cSrc modulated CX43 expression and Ca2+-handling protein levels. CONCLUSIONS: Cardiac-specific overexpression of Cav1 attenuated ventricular arrhythmia, improved Ca2+ cycling, and attenuated cardiac remodelling. These effects were attributed to modulation of CX43, normalized Ca2+-handling protein levels, improved Ca2+ homeostasis, and attenuated cardiac fibrosis.


Subject(s)
Cardiomyopathies , Caveolin 1 , Myocardial Ischemia , Animals , Rats , Arrhythmias, Cardiac/etiology , Cardiomyopathies/pathology , Caveolin 1/genetics , Caveolin 1/metabolism , Connexin 43/genetics , Connexin 43/metabolism , Myocardial Ischemia/complications , Myocardial Ischemia/metabolism , Myocytes, Cardiac/metabolism , Ventricular Remodeling
9.
Acta Pharmacol Sin ; 43(7): 1721-1732, 2022 Jul.
Article in English | MEDLINE | ID: mdl-34853445

ABSTRACT

Endoplasmic reticulum stress-mediated apoptosis plays a vital role in the occurrence and development of heart failure. Dapagliflozin (DAPA), a new type of sodium-glucose cotransporter 2 (SGLT2) inhibitor, is an oral hypoglycemic drug that reduces glucose reabsorption by the kidneys and increases glucose excretion in the urine. Studies have shown that DAPA may have the potential to treat heart failure in addition to controlling blood sugar. This study explored the effect of DAPA on endoplasmic reticulum stress-related apoptosis caused by heart failure. In vitro, we found that DAPA inhibited the expression of cleaved caspase 3, Bax, C/EBP homologous protein (CHOP), and glucose-regulated protein78 (GRP78) and upregulated the cardiomyoprotective protein Bcl-2 in angiotensin II (Ang II)-treated cardiomyocytes. In addition, DAPA promoted the expression of silent information regulator factor 2-related enzyme 1 (SIRT1) and suppressed the expression of activating transcription factor 4 (ATF4) and the ratios p-PERK/PERK and p-eIF2α/eIF2α. Notably, the therapeutic effect of DAPA was weakened by pretreatment with the SIRT1 inhibitor EX527 (10 µM). Simultaneous administration of DAPA inhibited the Ang II-induced transformation of fibroblasts into myofibroblasts and inhibited fibroblast migration. In summary, our present findings first indicate that DAPA could inhibit the PERK-eIF2α-CHOP axis of the ER stress response through the activation of SIRT1 in Ang II-treated cardiomyocytes and ameliorate heart failure development in vivo.


Subject(s)
Endoplasmic Reticulum Stress , Heart Failure , Animals , Apoptosis , Benzhydryl Compounds , Eukaryotic Initiation Factor-2/metabolism , Glucose/pharmacology , Glucosides , Heart Failure/drug therapy , Mice , Sirtuin 1/metabolism
10.
Opt Lett ; 47(21): 5485-5488, 2022 Nov 01.
Article in English | MEDLINE | ID: mdl-37219250

ABSTRACT

We propose red micro-LEDs integrated with plasmonic gratings, which demonstrate high efficiency and broad modulation bandwidth. The Purcell factor and external quantum efficiency (EQE) for an individual device can be improved up to 5.1 and 11%, respectively, due to the strong coupling between surface plasmons and multiple quantum wells. The cross talk effect between adjacent micro-LEDs can be efficiently alleviated as well, thanks to the high-divergence far-field emission pattern. Moreover, the 3-dB modulation bandwidth of the designed red micro-LEDs is predicted to be ∼ 528 MHz. Our results can be used to design high-efficiency and high-speed micro-LEDs for the applications of advanced light display and visible light communication.

11.
Front Pharmacol ; 12: 593682, 2021.
Article in English | MEDLINE | ID: mdl-33815099

ABSTRACT

Background: Angiotensin II (AngII) induces renal fibrosis, characterized by fibroblast proliferation, inflammatory cell infiltration and excessive extracellular matrix deposition, all of which was relevant closely to hypertension. The vagus nerve-related cholinergic anti-inflammatory pathway (CAP) modulates local and systemic inflammatory responses. The aim of present study was to determine the effect of CAP on renal inflammation and fibrosis. Methods and Results: AngII-induced hypertension was induced in vivo by 14-days low-dose AngII infusion from osmotic minipumps. We used GTS-21 dihydrochloride, a selective nicotinic acetylcholine receptor agonist. Daily intraperitoneal GTS-21 injection and/or vagotomy started after hypertension was confirmed and continued for 4 weeks. The elevated blood pressure caused by AngII was significantly attenuated by GTS-21. Improved baroreflex sensitivity was observed after GTS-21 administration. Masson stain and immunoblotting revealed that deposition of excessive fibrosis and overexpression of inflammatory cytokines induced by AngII was reduced by GTS-21. To determine the role of autonomic control in CAP, unilateral vagotomy was performed. Vagotomy weakened the effect of CAP on AngII-induced hypertension. In vitro, GTS-21 suppressed NF-κB activation, attenuated AngII-induced epithelial-mesenchymal transition and reduced inflammation and fibrosis in NRK-52E cells; α-bungarotoxin (α-Bgt, an α7-nAChR selective antagonist) partly inhibited these effects. Conclusion: CAP protected against AngII-induced hypertension via improvement in autonomic control, suppression of NF-κB activation, and reduction of renal fibrosis and inflammatory response.

12.
Sci Rep ; 9(1): 8796, 2019 Jun 19.
Article in English | MEDLINE | ID: mdl-31217468

ABSTRACT

Implementing selective-area p-type doping through ion implantation is the most attractive choice for the fabrication of GaN-based bipolar power and related devices. However, the low activation efficiency of magnesium (Mg) ions and the inevitable surface decomposition during high-temperature activation annealing process still limit the use of this technology for GaN-based devices. In this work, we demonstrate successful p-type doping of GaN using protective coatings during a Mg ion implantation and thermal activation process. The p-type conduction of GaN is evidenced by the positive Seebeck coefficient obtained during thermopower characterization. On this basis, a GaN p-i-n diode is fabricated, exhibiting distinct rectifying characteristics with a turn-on voltage of 3 V with an acceptable reverse breakdown voltage of 300 V. Electron beam induced current (EBIC) and electroluminescent (EL) results further confirm the formation of p-type region due to Mg ion implantation and subsequent thermal activation. This repeatable and uniform manufacturing process can be implemented in mass production of GaN devices for versatile power and optoelectronic applications.

13.
ACS Appl Mater Interfaces ; 11(7): 7131-7137, 2019 Feb 20.
Article in English | MEDLINE | ID: mdl-30676013

ABSTRACT

To suppress noise from full daylight background or environmental radiation, a spectrally selective solar-blind photodetector is widely required in many applications that need detection of light within a specific spectral range. Here, we present highly narrow-band solar-blind photodetectors by light polarization engineering of the anisotropic transitions in ß-Ga2O3 single crystals. The polarized transmittance characteristics reveal that direct transitions from valance subbands to the conduction band minimum are tuned between 4.53 and 4.76 eV for the light polarized E// c and E// b. The polarization-dependent photoresponsivity verifies that the order of fundamental band-to-band transitions obeys well the selection rules in terms of the valence-band splitting in the ß-Ga2O3 monoclinic crystal band structure. By combining an orthogonally aligned identical ß-Ga2O3 (100) single crystal filter with a detector measured at a chopper frequency of 17 Hz, a highly narrow-band detection is produced with a peak responsivity of 0.23 A/W at 262 nm, an EQE of 110%, a bandwidth of 10 nm, a light rejection ratio over 800, and a response time of 0.86 ms. This provides a new paradigm for a narrow-band solar-blind photodetector with broad applications where background noise emission needs to be suppressed.

14.
ACS Nano ; 12(7): 7327-7334, 2018 Jul 24.
Article in English | MEDLINE | ID: mdl-29894159

ABSTRACT

The ability to manipulate light-matter interaction in semiconducting nanostructures is fascinating for implementing functionalities in advanced optoelectronic devices. Here, we report the tailoring of radiative emissions in a ZnTe/ZnTe:O/ZnO core-shell single nanowire coupled with a one-dimensional aluminum bowtie antenna array. The plasmonic antenna enables changes in the excitation and emission processes, leading to an obvious enhancement of near band edge emission (2.2 eV) and subgap excitonic emission (1.7 eV) bound to intermediate band states in a ZnTe/ZnTe:O/ZnO core-shell nanowire as well as surface-enhanced Raman scattering at room temperature. The increase of emission decay rate in the nanowire/antenna system, probed by time-resolved photoluminescence spectroscopy, yields an observable enhancement of quantum efficiency induced by local surface plasmon resonance. Electromagnetic simulations agree well with the experimental observations, revealing a combined effect of enhanced electric near-field intensity and the improvement of quantum efficiency in the ZnTe/ZnTe:O/ZnO nanowire/antenna system. The capability of tailoring light-matter interaction in low-efficient emitters may provide an alternative platform for designing advanced optoelectronic and sensing devices with precisely controlled response.

15.
Nano Lett ; 18(6): 3414-3420, 2018 06 13.
Article in English | MEDLINE | ID: mdl-29781625

ABSTRACT

Semiconductor nanowire (NW) lasers have attracted considerable research effort given their excellent promise for nanoscale photonic sources. However, NW lasers currently exhibit poor directionality and high threshold gain, issues critically limiting their prospects for on-chip light sources with extremely reduced footprint and efficient power consumption. Here, we propose a new design and experimentally demonstrate a vertically emitting indium phosphide (InP) NW laser structure showing high emission directionality and reduced energy requirements for operation. The structure of the laser combines an InP NW integrated in a cat's eye (CE) antenna. Thanks to the antenna guidance with broken asymmetry, strong focusing ability, and high Q-factor, the designed InP CE-NW lasers exhibit a higher degree of polarization, narrower emission angle, enhanced internal quantum efficiency, and reduced lasing threshold. Hence, this NW laser-antenna system provides a very promising approach toward the achievement of high-performance nanoscale lasers, with excellent prospects for use as highly localized light sources in present and future integrated nanophotonics systems for applications in advanced sensing, high-resolution imaging, and quantum communications.

16.
Opt Express ; 26(24): 31965-31975, 2018 Nov 26.
Article in English | MEDLINE | ID: mdl-30650775

ABSTRACT

Wide-bandgap inorganic semiconductors based ultraviolet lasers bring versatile applications with significant advantages including low-power consumption, high-power output, robustness and long-term operation stability. However, flexible membrane lasers remain challenging predominantly due to the need for a lattice matched supporting substrate. Here, we develop a simple laser liftoff process to make freestanding single crystalline ZnO membranes that demonstrate low-threshold ultraviolet stimulated emissions together with large sized dimension (> 2 mm), ultralow-weight (m/A<15 g/m2) and excellent flexibility. The 2.6 µm-thick crack-free ZnO membrane exhibits well-retained single crystallinity and enhanced excitonic emissions while the defect-related emissions are completely suppressed. The inelastic exciton-exciton scattering stimulated emissions with increased spontaneous emission rate is obtained with a reduced threshold of 0.35 MW/cm2 in the ZnO membrane transferred onto a flexible polyethylene naphthalate substrate. Theoretical simulations reveal that it is a synergetic effect of the increased quantum efficiency via Purcell effect and the improved optical gain due to vertical directional waveguiding of the membrane, which functions as a Fabry-Perot photonic resonator due to the refractive index contrast at ZnO-air boundaries. With simple architecture, efficient exciton recombination and easy fusion with waveguide system, the ZnO membranes provide an alternative platform to develop compact low-threshold ultraviolet excitonic lasers.

17.
ACS Appl Mater Interfaces ; 9(42): 36997-37005, 2017 Oct 25.
Article in English | MEDLINE | ID: mdl-28975779

ABSTRACT

The metastable α-phase Ga2O3 is an emerging material for developing solar-blind photodetectors and power electronic devices toward civil and military applications. Despite its superior physical properties, the high quality epitaxy of metastable phase α-Ga2O3 remains challenging. To this end, single crystalline α-Ga2O3 epilayers are achieved on nonpolar ZnO (112̅0) substrates for the first time and a high performance Au/α-Ga2O3/ZnO isotype heterostructure-based Schottky barrier avalanche diode is demonstrated. The device exhibits self-powered functions with a dark current lower than 1 pA, a UV/visible rejection ratio of 103 and a detectivity of 9.66 × 1012 cm Hz1/2 W-1. Dual responsivity bands with cutoff wavelengths at 255 and 375 nm are observed with their peak responsivities of 0.50 and 0.071 A W-1 at -5 V, respectively. High photoconductive gain at low bias is governed by a barrier lowing effect at the Au/Ga2O3 and Ga2O3/ZnO heterointerfaces. The device also allows avalanche multiplication processes initiated by pure electron and hole injections under different illumination conditions. High avalanche gains over 103 and a low ionization coefficient ratio of electrons and holes are yielded, leading to a total gain over 105 and a high responsivity of 1.10 × 104 A W-1. Such avalanche heterostructures with ultrahigh gains and bias-tunable UV detecting functionality hold promise for developing high performance solar-blind photodetectors.

18.
Sci Rep ; 7(1): 7503, 2017 08 08.
Article in English | MEDLINE | ID: mdl-28790363

ABSTRACT

Intermediate band solar cells (IBSCs) are conceptual and promising for next generation high efficiency photovoltaic devices, whereas, IB impact on the cell performance is still marginal due to the weak absorption of IB states. Here a rational design of a hybrid structure composed of ZnTe:O/ZnO core-shell nanowires (NWs) with Al bowtie nanoantennas is demonstrated to exhibit strong ability in tuning and enhancing broadband light response. The optimized nanowire dimensions enable absorption enhancement by engineering leaky-mode dielectric resonances. It maximizes the overlap of the absorption spectrum and the optical transitions in ZnTe:O intermediate-band (IB) photovoltaic materials, as verified by the enhanced photoresponse especially for IB states in an individual nanowire device. Furthermore, by integrating Al bowtie antennas, the enhanced exciton-plasmon coupling enables the notable improvement in the absorption of ZnTe:O/ZnO core-shell single NW, which was demonstrated by the profound enhancement of photoluminescence and resonant Raman scattering. The marriage of dielectric and metallic resonance effects in subwavelength-scale nanowires opens up new avenues for overcoming the poor absorption of sub-gap photons by IB states in ZnTe:O to achieve high-efficiency IBSCs.

19.
J Huazhong Univ Sci Technolog Med Sci ; 37(3): 412-418, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28585128

ABSTRACT

Nasal polyp (NP) is a common chronic inflammatory disease of the nasal cavity and sinuses. Although some authors have suggested that NP is related to inflammatory factors such as interleukin (IL)-1ß, IL-5, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor (TNF)-α, and IL-17, the mechanisms underlying the pathogenesis and progression of NP remain obscure. This study investigated the expression and distribution of IL-17 and syndecan-1 in NP, and explored the roles of these two molecules in the pathogenesis of eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) and non-Eos CRSwNP. Real-time PCR and immunohistochemistry were used to detect the expression of IL-17 and syndecan-1 in samples [NP, unciform process (UP) from patients with CRS, and middle turbinate (MT) from healthy controls undergoing pituitary tumor surgery]. The results showed that the expression levels of IL-17 and syndecan-1 were upregulated in both NP and UP tissues, but both factors were higher in NP tissues than in UP tissues. There was no significant difference in IL-17 levels between the Eos CRSwNP and non-Eos CRSwNP samples, and syndecan-1 levels were increased in the non-Eos CRSwNP tissues as compared with those in Eos CRSwNP tissues. In all of the groups, there was a close correlation between the expression of IL-17 and syndecan-1 in nasal mucosa epithelial cells, glandular epithelial cells, and inflammatory cells, suggesting that IL-17 and syndecan-1 may play a role, and interact with each other, in the pathogenesis of non-Eos CRSwNP.


Subject(s)
Eosinophilia/genetics , Interleukin-17/genetics , Nasal Polyps/genetics , Rhinitis/genetics , Sinusitis/genetics , Syndecan-1/genetics , Case-Control Studies , Chronic Disease , Eosinophilia/immunology , Eosinophilia/pathology , Epithelial Cells/immunology , Epithelial Cells/pathology , Gene Expression Regulation , Humans , Interleukin-17/immunology , Nasal Cavity/immunology , Nasal Cavity/pathology , Nasal Mucosa/immunology , Nasal Mucosa/pathology , Nasal Polyps/complications , Nasal Polyps/immunology , Nasal Polyps/pathology , Rhinitis/complications , Rhinitis/immunology , Rhinitis/pathology , Sinusitis/complications , Sinusitis/immunology , Sinusitis/pathology , Syndecan-1/immunology
20.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-238361

ABSTRACT

Nasal polyp (NP) is a common chronic inflammatory disease of the nasal cavity and sinuses.Although some authors have suggested that NP is related to inflammatory factors such as interleukin (IL)-1β,IL-5,IL-8,granulocyte-macrophage colony-stimulating factor (GM-CSF),tumor necrosis factor (TNF)-α,and IL-17,the mechanisms underlying the pathogenesis and progression of NP remain obscure.This study investigated the expression and distribution of IL-17 and syndecan-1 in NP,and explored the roles of these two molecules in the pathogenesis of eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) and non-Eos CRSwNP.Real-time PCR and immunohistochemistry were used to detect the expression of IL-17 and syndecan-1 in samples [NP,unciform process (UP) from patients with CRS,and middle turbinate (MT) from healthy controls undergoing pituitary tumor surgery].The results showed that the expression levels of IL-17 and syndecan-1 were upregulated in both NP and UP tissues,but both factors were higher in NP tissues than in UP tissues.There was no significant difference in IL-17 levels between the Eos CRSwNP and non-Eos CRSwNP samples,and syndecan-1 levels were increased in the non-Eos CRSwNP tissues as compared with those in Eos CRSwNP tissues.In all of the groups,there was a close correlation between the expression of IL-17 and syndecan-1 in nasal mucosa epithelial cells,glandular epithelial cells,and inflammatory cells,suggesting that IL-17 and syndecan-1 may play a role,and interact with each other,in the pathogenesis ofnon-Eos CRSwNP.

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