We investigated the optical and electrical properties of red AlGaInP light-emitting diodes (LEDs) as functions of chip size, p-cladding layer thickness, and the number of multi-quantum wells (MQWs). ...External quantum efficiency (EQE) decreased with decreasing chip size. The ideality factor gradually increased from 1.47 to 1.95 as the chip size decreased from 350 μm to 15 μm. This indicates that the smaller LEDs experienced larger carrier loss due to Shockley-Read-Hall nonradiative recombination at sidewall defects. S parameter, defined as ∂lnL/∂lnI, increased with decreasing chip size. Simulations and experimental results showed that smaller LEDs with 5 pairs of MQWs had over 30% higher IQE at 5 A/cm
than the LED with 20 pairs of MQWs. These results show that the optimization of the number of QWs is needed to obtain maximum EQE of micro-LEDs.
We investigated how the performance and reliability of AlGaInP-based red (620 nm) micro-light-emitting diodes (micro-LEDs) (25 × 17 μm2) were influenced by the use of n-AlInP ohmic layer and ...distributed Bragg reflector (DBR). The AlGaAs-based DBR showed reflectivity of 94.9% at 622 nm with a 14 nm-stopband width. The micro-LEDs with n-GaAs gave slightly lower forward voltages by 0.013 - 0.021 V than those with n-Al0.5In0.5P/n-Al0.6Ga0.4As and n-Al0.5In0.5P/DBR. However, the micro-LEDs with n-Al0.5In0.5P/n-Al0.6Ga0.4As and n-Al0.5In0.5P/DBR gave 61% and 125% higher light output power at 20 μA compared with that with n-GaAs. It was shown that after annealing at 120 °C for 2,000 h, the forward voltage and the light output power at 4.7 A/cm2 of the micro-LEDs with n-Al0.5In0.5P/DBR were degraded by 0.09% and 6.33%, respectively, with reference to those before annealing.
The future of safe cell-based therapy rests on overcoming teratoma/tumor formation, in particular when using human pluripotent stem cells (hPSCs), such as human embryonic stem cells (hESCs) and human ...induced pluripotent stem cells (hiPSCs). Because the presence of a few remaining undifferentiated hPSCs can cause undesirable teratomas after transplantation, complete removal of these cells with no/minimal damage to differentiated cells is a prerequisite for clinical application of hPSC-based therapy. Having identified a unique hESC signature of pro- and antiapoptotic gene expression profile, we hypothesized that targeting hPSC-specific antiapoptotic factor(s) (i.e., survivin or Bcl10) represents an efficient strategy to selectively eliminate pluripotent cells with teratoma potential. Here we report the successful identification of small molecules that can effectively inhibit these antiapoptotic factors, leading to selective and efficient removal of pluripotent stem cells through apoptotic cell death. In particular, a single treatment of hESC-derived mixed population with chemical inhibitors of survivin (e.g., quercetin or YM155) induced selective and complete cell death of undifferentiated hPSCs. In contrast, differentiated cell types (e.g., dopamine neurons and smooth-muscle cells) derived from hPSCs survived well and maintained their functionality. We found that quercetin-induced selective cell death is caused by mitochondrial accumulation of p53 and is sufficient to prevent teratoma formation after transplantation of hESC- or hiPSC-derived cells. Taken together, these results provide the “proof of concept” that small-molecule targeting of hPSC-specific antiapoptotic pathway(s) is a viable strategy to prevent tumor formation by selectively eliminating remaining undifferentiated pluripotent cells for safe hPSC-based therapy.
•Electrochemical doping on SWCNTs network film was performed with multiple CV scans.•Electronic structure of SWCNTs network was analysed with in-depth Raman study.•Selective oxidation of m-SWCNTs ...endowed the enhanced performance for the DA sensing.•DA was discriminated from the mixture of UA and AA with a LOD of sub-uM.•Eox-SWCNTs network film showed the determination of DA even on curved structure.
Transparent and flexible single-walled carbon nanotube (SWCNT) network electrodes were used for the determination of neurotransmitters. The surface of SWCNT network film was oxidised by multiple electrochemical anodic scans, thereby the electronic structure of SWCNTs network film was modulated with p-typed doping. Herein, we analysed the electronic structure in-depth by resonant Raman spectroscopy with two different wavelength lasers (514 and 633 nm) and UV–vis-NIR absorption spectroscopy. From this analysis, it is found that the electrochemical oxidation process selectively occurred on metallic SWCNTs surface in the mixture of metallic and semiconducting SWCNTs. Interestingly, after electrochemical oxidation, the charge transfer resistance was observed to have decreased by 52%, compared to that of a SWCNT network electrode before treatment (4.7 kΩ). This is probably due to the suppression of Schottky barrier of junctions between metallic and semiconducting SWCNT bundles. The enhanced electrocatalytic activity of a SWCNT network film by electrochemical doping (Eox-SWCNT network film) has enabled discrimination of dopamine (DA) from a mixture with ascorbic acid (AA) and uric acid (UA). The limit of detection was estimated to be 0.51 μM DA in the presence of 100 μM AA and 10 μM UA, and the DA sensing activity was not significantly affected even using a bent configuration of Eox-SWCNT network film. The simple and eco-friendly electrochemical doping with multiple cyclic voltammetric scans can be a powerful tool to modulate the electronic energy in the band structure of carbon-related materials.
ABSTRACT
The vertebrate skeletal system has various functions, including support, movement, protection, and the production of blood cells. The development of cartilage and bones, the core components ...of the skeletal system, is mediated by systematic inter‐ and intracellular communication among multiple signaling pathways in differentiating progenitors and the surrounding tissues. Recently, Pannexin (Panx) 3 has been shown to play important roles in bone development in vitro by mediating multiple signaling pathways, although its roles in vivo have not been explored. In this study, we generated and analyzed Panx3 knockout mice and examined the skeletal phenotypes of panx3 morphant zebrafish. Panx3‐/‐ embryos exhibited delays in hypertrophic chondrocyte differentiation and osteoblast differentiation as well as the initiation of mineralization, resulting in shortened long bones in adulthood. The abnormal progression of hypertrophic chondrogenesis appeared to be associated with the sustained proliferation of chondrocytes, which resulted from increased intracellular cAMP levels. Similarly, osteoblast differentiation and mineralization were delayed in panx3 morphant zebrafish. Taken together, our results provide evidence of the crucial roles of Panx3 in vertebrate skeletal development in vivo.—Oh, S.‐K., Shin, J.‐O., Baek, J.‐I., Lee, J., Bae, J. W., Ankamerddy, H., Kim, M.‐J., Huh, T.‐L., Ryoo, Z.‐Y., Kim, U.‐K., Bok, J., Lee, K.‐Y. Pannexin 3 is required for normal progression of skeletal development in vertebrates. FASEB J. 29, 4473‐4484 (2015). www.fasebj.org
Developing an effective and efficient recycling process for marine debris (MD) is one of the most urgent issues to maintain environmental sustainability on Earth. However, restricted storage ...capacities and secondary pollution (e.g., microbial adhesion, putrefaction) limit the proper MD recycling. Here, we proposed a complete eco-friendly low-temperature MD pulverizing system that utilizes excessive liquefied natural gas (LNG) cold energy (LCE) in an LNG propulsion ship to improve the efficiency and effectiveness of MD recycling. The prototype design of the low-temperature pulverization (LTP) system showed that consumable refrigerant (liquid nitrogen) up to 2831 kg per hour could be substituted. Furthermore, with a 20% ship output, 1250 kg of MD could be treated with 363 kg of additional refrigerant. In addition, LTP systems utilizing LCE could increase the storage capacity by more than 10 times compared to bulk MD while minimizing the required energy consumption. To determine the feasibility of LTP for MD recycling, four types of plastics obtained from actual MD from a coastal area in Busan, Korea were classified and tested.
Myocardial infarction (MI) causes serious loss of cardiac muscle and dysfunction. To restore MI, exogenous stem cells should be efficiently delivered. However, due to severe physical and ...physiological cardiac environment, recent strategies have faced challenges, including low cell persistence, low integration, and delayed therapeutic effects. Herein, we proposed mesenchymal stem cell (MSC) therapeutic platform using adhesive protein-based immiscible condensed liquid system (APICLS) derived from bioengineered mussel adhesive protein (MAP). With high encapsulation efficiency and survival rate of encapsulated MSCs, APICLS was successfully grafted by intramyocardial injection and distributed throughout the scarred myocardium. Its underwater adhesiveness and biocompatibility fostered integration with damaged tissue, resulting in high cell persistence and maximized paracrine effects. Bioactive molecules released from APICLS with MSCs induced angiogenesis and cardioprotection, delayed cardiac remodeling, reduced fibrosis, and recovered contractive force. Thus, our proposed strategy represents an innovative approach for recovering infarcted cardiac tissues with damaged structural and contractive function.
The unique physiochemical properties of APICLS allow transplanted MSCs to stably remain and to be rapidly integrated at the injected site, resulting in enhanced therapeutic efficacy through maximized paracrine effects. Display omitted
•Fluid-immiscible sticky platform helps prolonged cell retention in harsh condition.•Surviving cells regenerate infarcted myocardium with maximized paracrine effect.•This study suggests a promising assessment for direct stem cell injection strategy.
Hydrogels with 0.1 mol of three kinds of metal oxides are fabricated to improve shielding performance with ductility. Fe
2
O
3
, WO
3
, and PbO
2
micropowders as a supplement are used to shield γ-ray ...radiation. Transmittance of γ-ray is measured for the hydrogels according to the energy level of γ-ray from Cs-137 (0.662 MeV) and Co-60 (1.173 and 1.332 MeV). Subsequently, tenth value layers (TVLs) as thickness to nearly shield radiation are calculated using the obtained attenuation coefficient from the transmittance. The shielding performance as the transmittance and attenuation coefficient is improved according to the atomic number of contained metal. Among Fe
2
O
3
, WO
3
, and PbO
2
composite, the PbO
2
composite has the lowest transmittance and highest attenuation coefficient for the all γ-ray energy range. The calculated TVLs of the PbO
2
and WO
3
composites are 12.65 and 13.62 cm for Co-60, respectively. The difference of TVLs between the PbO
2
and WO
3
composites is merely small as 1 cm, and the tungsten metal is not harmful to human and environment, unlike lead. As a result, it is suggested that the WO
3
composite is suitable for the soft radiation shielding materials of the radioactive waste multiple containers with appropriate shielding and cushioning performance.
Gynecologic malignancy is one of the leading causes of mortality in female adults worldwide. Comprehensive genomic analysis has revealed a list of molecular aberrations that are essential to ...tumorigenesis, progression, and metastasis of gynecologic tumors. However, targeting such alterations has frequently led to treatment failures due to underlying genomic complexity and simultaneous activation of various tumor cell survival pathway molecules. A compilation of molecular characterization of tumors with pharmacological drug response is the next step toward clinical application of patient-tailored treatment regimens.
Toward this goal, we establish a library of 139 gynecologic tumors including epithelial ovarian cancers (EOCs), cervical, endometrial tumors, and uterine sarcomas that are genomically and/or pharmacologically annotated and explore dynamic pharmacogenomic associations against 37 molecularly targeted drugs. We discover lineage-specific drug sensitivities based on subcategorization of gynecologic tumors and identify TP53 mutation as a molecular determinant that elicits therapeutic response to poly (ADP-Ribose) polymerase (PARP) inhibitor. We further identify transcriptome expression of inhibitor of DNA biding 2 (ID2) as a potential predictive biomarker for treatment response to olaparib.
Together, our results demonstrate the potential utility of rapid drug screening combined with genomic profiling for precision treatment of gynecologic cancers.
We investigated the effect of plasma-etching on the electrical and optical performance of lateral AlGaInP-based red micro-LEDs as a function of etching time, where plasma-etched Ag particles were ...used as masks. For the sample etched for 12 s, around 33% of the sample surface were randomly etched, whereas for the sample etched for 24 s, nearly 60% were randomly etched with additional nanoscale hillocks. Regardless of etching times, all samples exhibited similar forward voltages of 1.944-1.929 V at <inline-formula> <tex-math notation="LaTeX">20~\mu \text{A} </tex-math></inline-formula> and reverse leakage currents of <inline-formula> <tex-math notation="LaTeX">1\times 10^{-8} </tex-math></inline-formula> A at −10 V. The micro-LEDs fabricated with 12 s-etched and 24 s-etched <inline-formula> <tex-math notation="LaTeX">p </tex-math></inline-formula>-GaP gave 26.2% and 42.3% higher light output powers at <inline-formula> <tex-math notation="LaTeX">20~\mu \text{A} </tex-math></inline-formula>, respectively, than the one with unetched <inline-formula> <tex-math notation="LaTeX">p </tex-math></inline-formula>-GaP. The <inline-formula> <tex-math notation="LaTeX">S </tex-math></inline-formula> parameter decreased with increasing forward current and etching time. The electroluminescence (EL) peak intensities of the micro-LEDs were consistent with their light output performance and included shoulder peaks at 612 nm. Emission images showed that the micro-LEDs with the 24 s-etched <inline-formula> <tex-math notation="LaTeX">p </tex-math></inline-formula>-GaP revealed the most intense and uniform emission area among the three samples.
PDF
