We demonstrate the realization of the high-brightness and high-efficiency light emitting diodes (LEDs) using dislocation-free indium gallium nitride (InGaN)/gallium nitride (GaN) multiquantum-well ...(MQW) nanorod (NR) arrays by metal organic-hydride vapor phase epitaxy (MO−HVPE). MQW NR arrays (NRAs) on sapphire substrate are buried in spin-on glass (SOG) to isolating individual NRs and to bring p-type NRs in contact with p-type electrodes. The MQW NRA LEDs have similar electrical characteristics to conventional broad area (BA) LEDs. However, due to the lack of dislocations and the large surface areas provided by the sidewalls of NRs, both internal and extraction efficiencies are significantly enhanced. At 20 mA dc current, the MQW NRA LEDs emit about 4.3 times more light than the conventional BA LEDs, even though overall active volume of the MQW NRA LEDs is much smaller than conventional LEDs. Moreover, the fabrication processes involved in producing MQW NRA LEDs are almost the same for conventional BA LEDs. It is, thus, not surprising that the total yield of these MQW NRA LEDs is essentially the same as that of conventional BA LEDs. The present method of utilizing dislocation-free MQW NRA LEDs is applicable to super-bright white LEDs as well as other semiconductor LEDs for improving total external efficiency and brightness of LEDs.
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IJS, KILJ, NUK, PNG, UL, UM
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Nowadays, solid-state inorganic-organic hybrid solar cells based on one-dimensional (1D) inorganic semiconducting nanostructures and organic polymers are believed to offer convincing ...solutions for the realm of next generation solar cells. In this regard, 1D ZnCdS nanowire (NW) arrays were fabricated on transparent conducting substrates through a catalyst free co-evaporation method and their wurtzite structural characteristics, 1D morphological layout and valence state/composition were studied in detail using X-ray diffraction, high-resolution electron microscopy and X-ray photoelectron spectroscopy, respectively. The existence of deep level traps and optical band gap of ZnCdS NWs were additionally studied using room-temperature cathodoluminescence and UV–vis absorbance measurements. The inorganic-organic hybrid cells were then fabricated using these NWs via spin coating poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate) based polymers. The morphological dissemination of the polymer deposits on NWs were also studied individually by electron microscopy. The solar cell (J-V) characteristics of the fabricated architectures were investigated at room-temperature and as a function of temperature and different intensities of incident light irradiation. The trap energy of the devices was noted to decrease from 68.1 to 40.7eV, suggesting the active role of trap sites that could have originated from the surface defects and other structural disorders across the hybrid heterostructures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Here in, we report the fabrication of thin two dimensional (2D) ZnO nanosheets (NSs) flexible piezo-phototronic ultraviolet (UV) photodetector (PD). The morphological and optical properties of the ...as-synthesized ZnO NSs is characterized in detail. The flexible Ag–ZnO NSs-Ag lateral PDs are fabricated on the polyethylene terephthalate (PET) substrate. A striking photoresponse is observed for 2D-ZnO under UV illumination. Furthermore, by introducing a strain (in the form of bending) the photocurrent and responsivity of this PD can be modulated via piezo-phototronic effect, emerging from the ZnO nanosheets. The photocurrent enhancement under bending could be attributed to the piezo polarization charges produced at ZnO/Ag interface due to strain. This piezo polarization charges result in the modulation of Schottky barrier (SB) height at the semiconductor/metal interface and induce improved photogenerated charge carriers and reduced recombination probability to result enhanced performances from the ZnO NSs photodetector. The physical mechanism involved in the enhancement of photocurrent via piezo-phototronic is proposed to explain change in SB height at semiconductor/metal interface using the band diagrams. This results demonstrates an efficient prototype of the piezo-phototronic PD based on thin ZnO NSs, which provides an effective pathway to enhance the performance of optoelectronic devices.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Etching of materials on the nanoscale is a challenging but necessary process in nanomaterials science. Gas sensing using a single ZnO nanocactus (NC), which was prepared by facile isotropic ...nanoetching of zinc oxide nanorods (NR) grown by chemical vapor deposition (CVD) using an organic photoresist (PR) by a thermochemical reaction, is reported in this work. PR consists of carboxylic acid groups (COOH) and cyclopentanone (C5H8O), which can react with zinc and oxygen atoms, respectively, on the surface of a ZnO NR. The thermochemical reaction is controllable by varying the concentration of PR and reaction time. A gas sensor was fabricated using a single NC. Gas sensing was tested using different gases such as CH4, NH3 and carbon monoxide (CO). It was estimated that the surface area of a ZnO NC in the case of 50% PR was found to increase four-fold. When compared with a single ZnO NR gas sensor, the sensitivity of a ZnO NC was found to increase four-fold. This increase in sensitivity is attributed to the increase in surface area of the ZnO NC. The formed single ZnO NC gas sensor has good stability, response and recovery time.
Among the five members of the dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK) family, the cellular functions of DYRK3 have not been fully elucidated. Some studies have indicated ...limited physiological roles and substrates of DYRK3, including promotion of glioblastoma, requirement in influenza virus replication, and coupling of stress granule condensation with mammalian target of rapamycin complex 1 signaling. Here, we demonstrate that serum deprivation causes a decrease in intracellular DYRK3 levels via the proteolytic autophagy pathway, as well as the suppression of DYRK3 gene expression. To further demonstrate how DYRK3 affects cell viability, especially in neurons, we used a yeast two-hybrid assay and identified multiple DYRK3-binding proteins, including SNAPIN, a SNARE-associated protein implicated in synaptic transmission. We also found that DYRK3 directly phosphorylates SNAPIN at the threonine (Thr) 14 residue, increasing the interaction of SNAPIN with other proteins such as dynein and synaptotagmin-1. In central nervous system neurons, SNAPIN is associated with and mediate the retrograde axonal transport of diverse cellular products from the distal axon terminal to the soma and the synaptic release of neurotransmitters, respectively. Moreover, phosphorylation of SNAPIN at Thr-14 was found to positively modulate mitochondrial retrograde transport in mouse cortical neurons and the recycling pool size of synaptic vesicles, contributing to neuronal viability. In conclusion, the present study demonstrates that DYRK3 phosphorylates SNAPIN, positively regulating the dynein-mediated retrograde transport of mitochondria and SNARE complex-mediated exocytosis of synaptic vesicles within the neurons. This finding further suggests that DYRK3 affects cell viability and provides a novel neuroprotective mechanism.
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•A novel flexible photodetector composed of 2D-ZnO/1D-GaN was fabricated through two step growth method.•A striking photoresponse was observed for 2D-ZnO/1D-GaN heterojunction under ...UV illumination.•Piezo-phototronic effect is utilized to enhance the performances of photodetector.•The photoresponsitivity of the photodetector enhances by one order under tensile strain.
Here in, we report on the fabrication of a flexible ultraviolet photodetector composed of two dimensional (2D) ZnO nanosheets (NSs) and one dimensional (1D) GaN nanorods (NRs). ZnO NSs were grown on the surface of GaN NRs to form 2D/1D heterojunction via simple hydrothermal method. A striking photoresponse was observed across 2D-ZnO/1D-GaN heterojunction under UV illumination. The photoresponsitivity and detectivity of the photodetector enhanced by two order magnitude than that of 1D GaN NRs. Furthermore, under a tensile strain the photoresponsivity of this photodetector was also tuned through piezo-phototronic effect arising from ZnO NSs. Due to lowering of barrier height under the application of strain, more photogenerated electron-hole pairs can transport through the heterojunction without recombination, resulting in enhanced photorespositivity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
7.
Cardiac papillary fibroelastoma Ryu, Sang-Wan; Beom, Min Sun; Kim, Sung Ryong ...
Revista portuguesa de cardiologia,
07/2015, Volume:
34, Issue:
7-8
Journal Article
Peer reviewed
Open access
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study was undertaken to evaluate the antithrombotic effects of Korean Red Ginseng (KRG) and its new prescription (KRGP) consisting of five herbs such as
Korean red ginseng,
Ganoderma,
Cinnamomi ...Cortex,
Glycyrrhizae Radix and
Laminaria. In rats with blood stasis induced by high molecular weight dextran, KRG and KRGP significantly restored not only the number of platelets and fibrinogen, but also suppressed the fibrin degradation products (FDP) to normal range. In platelet aggregation assay with human platelet rich plasma (PRP), KRG and KRGP significantly inhibited thrombin and collagen-induced platelet aggregation. The IC
50 values of KRG and KRGP were >2 and 0.23±0.01 mg/ml for thrombin, 0.32±0.01 and 0.17±0.02 mg/ml for collagen and 0.72±0.25 and >2 mg/ml for ADP, respectively. In coagulation assay, KRG and KRGP significantly prolonged activated partial prothrombin time (APPT) and prothrombin time (PT) as compared with control data. KRGP was found to be more effective than KRG alone on antithrombotic activity. These results suggest that KRGP may exert its antithrombotic activity due to inhibition of platelet aggregation and coagulation activity more than KRG.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper presents an open innovation strategy by identifying the patent impact index and cooperation network through patent analysis for leading companies developing technology in the UAM field. ...Among companies developing UAM technology, patent analysis was conducted on the leading companies with active patent activities, technology classification was used to match companies by parts, and a technical capability index was utilized to identify the companies. When developing UAM technology in the future, this can help companies seek effective partners to improve competitiveness in technology development. To the best of our knowledge, the work done in this paper is unprecedented, as it suggests methods for patent analysis and verifies them by analyzing the UAM patents with the proposed method.
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