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Rechargeable sodium-ion batteries (SIBs) have received significant attention as a promising alternative to traditional lithium-ion counterparts for large-scale energy storage applications owing to the low cost and abundance of sodium resources. Herein, we demonstrate the photonic irradiated mesoporous reduced graphene oxide (rGO)-TiO2 nanocomposite architectures using environmentally benign, ultrafast split-second (millisecond) intense pulsed light (IPL) process at room temperature. The photonic IPL irradiation spontaneously triggers the deoxygenation of graphene oxide (GO) and the simultaneous structural engineering of TiO2 nanocomposites. The precisely controlled IPL irradiation (energy density of 10 J cm−2) exhibits excellent conductivity, high surface area, and outstanding electrochemical performance as a green anode material for SIBs. The photonic IPL irradiated rGO-TiO2 nanocomposite delivers a high reversible capacity of 244 mAh g−1 at 0.1 Ag-1, a high rate performance of 112 mAh g−1 at 1 Ag-1, and high cycling stability compared to pristine GO-TiO2 and conventional furnace annealed rGO-TiO2 (FH-rGO-TiO2) nanocomposites. The detailed electrochemical analysis suggests that the improved capacitance contribution results from the fast kinetics of the IPL irradiated rGO-TiO2 nanocomposite anode. This work provides new insight into the fabrication of versatile, cost-effective techniques for developing advanced electrode materials for energy applications.

Summary Metal halide perovskites (MHPs) are being widely studied as a light-absorber for high-efficiency solar cells. With efforts being made throughout the globe, the power conversion efficiency of MHP solar cells has recently soared up to 25.2%. MHPs are now being spotlighted as a next-generation light-emitter as well. Their high color purity and solution-processability are of particular interest for display applications, which in general benefit from wide color gamut and low-cost high-resolution subpixel patterning. For this reason, research activities on perovskite light-emitting diodes (LEDs) are rapidly growing, and their external quantum efficiencies have been dramatically improved to over 20%. As more and more research groups with different backgrounds are working on these perovskite optoelectronic devices, the demand is growing for standard methods for accurate efficiency measurement that can be agreed upon across the disciplines and, at the same time, can be realized easily in the lab environment with due diligence. Herein, optoelectronic characterization methods are revisited from the viewpoint of MHP solar cells and LEDs. General efficiency measurement practices are first reviewed, common sources of errors are introduced, and guidelines for avoiding or minimizing those errors are then suggested to help researchers in fields develop the best measurement practice.

There is great interest in carbon-based printed electronics as a promising technology to achieve lighter, thinner and flexible electronic devices at low-costs. Despite the surge of enthusiasm in this area, research advances in printed electronics are not yet able to realize diverse carbon structures yet. This is due to the limitations in conventional solution-based printing methods (e.g., inkjet printing, roll-to-roll, screen printing). Processes such as polymer phase-inversion offer one possibility but a much faster and efficient method should be devised for reliable production. Here, we demonstrate laser printing combined with intense pulsed-light (IPL) annealing as a novel and efficient technique which can form inter-connected carbon spheres electrode on flexible polymer substrate. Our observations show that the printed patterns from a laser printer consist of a solid-state polymer matrix with inorganic nanoparticles randomly embedded inside. Through ultrafast (5 ms) IPL treatment, core/shell type nanosphere arrays of carbon-coated SiO2 were successfully fabricated, which could be used as a functional platform for highly selective NO2 gas sensing.

Solution-processed nanostructured mesoporous rutile phase titanium dioxides (TiO2) are a fascinating class of materials for energy applications owing to their remarkable properties, including thermal stability. The unique lattice structure of rutile TiO2 (R-TiO2) leads to multifaceted physicochemical properties, which influence its performances. We here report the preparation of mesoporous R-TiO2 via a simple and scalable solution process at a low temperature (

An ideal conducting polymer anode (CPA) in organic and perovskite light-emitting diodes (LEDs) requires high electrical conductivity κ, high work function WF, and prevention of exciton quenching between an anode and an overlying emitting layer. However, increasing the κ and WF at the same time has been a very challenging unsolved issue due to their trade-off relationship: previous approaches to increase the WF have reduced the films’ κ and vice versa. Therefore, delicate molecular scale control of the conducting polymer compositions are required to solve this fundamental issue. Here, we introduce an effective molecular scale control strategy to decouple the WF with κ in a CPA while maintaining blocking capability of exciton quenching. This change resulted in a high current efficiency up to 52.86 cd A−1 (10.93% ph el−1) in green polycrystalline perovskite LEDs. Our results provide a significant clue to develop effective CPAs for highly-efficient organic and perovskite LEDs.

Metabolic rewiring or reprogramming is the alteration of metabolism in living organisms, leading to disordered states aberrant from homeostasis. As large amounts of omics data become available, complex mechanisms leading to or driven by metabolic rewiring of cells can be better understood using reconstructed context-specific genome-scale metabolic models (GEMs). Here, we review recent advances in reconstructing context-specific GEMs for studying metabolic rewiring of human cells or tissues, from generic GEMs and omics databases to multiomics data integration methods. Also, we review recent studies that use context-specific GEMs to obtain insights such as identifying key regulators or therapeutic targets. Analyses of recent trends indicate the importance of integrating context-specific GEMs with multiscale networks for understanding metabolic diseases and advancing precision medicine.

Achieving both performances and functionalities of energy storage devices at extreme conditions remains a critical challenge due to the property trade-offs of materials. Here, we demonstrate highly ion-conducting, stretchable, and ultradurable double network (DN) ionogel films, where ionic liquids are confined in chemically-coupled DNs consisting of hard and soft polymers, for high-temperature flexible supercapacitors (hfSCs). Both mechanical and electrochemical integrities at high temperatures are attributed to the unique DN structure and thermally activated ionic transport of the ionogels. Even at 100 °C, the DN ionogel film demonstrates remarkable properties, such as the ionic conductivity of 36.8 mS cm−1, the tensile strength of 1.4 MPa, stretchability of 500%, and dissipation energy of 216 kJ m−3. Thus, the hfSCs achieve the highest energy density of 51.0 Wh kg−1 at 180 °C among previous solid-state SCs, showing extreme durability of 91% over 100,000 cycles and functional hybrid system at both elevated temperatures and bent states.

In flexible display technology, the electronic components are constructed on a flexible polymer substrate film and are released from a carrier glass with the detachment of the polymer film. During the debonding process, however, strong polymer-glass bonding often causes the formation of wrinkles and buckles of the polymer film and thereby the damage of electronics. Here, we report on a novel debonding layer (DBL) of graphene/MnO hybrids for scalable and stable detachment of the polymer film. The DBL acted to decrease the polymer-glass bonding strength. The weakly bonded polymer film was safely detached from the glass in ∼170 s by gas-evolution at DBL. The gas-induced debonding (GID) process was functional in H2O2 solution, not in other tested solutions, indicating its good solution selectivity. As proof of concept, flexible thin-film transistors (TFTs) were fabricated using our DBL and exhibited the similar transfer characteristics before and after the GID process. We believe our DBL will also pave the ways for flexible photovoltaic cells, flexible flash memories and flexible sensor arrays as well as flexible displays.

Owing to their unique properties and biological activities, ionic liquids (ILs) have attracted research interest in pharmaceutics and medicine. Hypoxia-inducible factor (HIF)- 1α is an attractive cancer drug target involved in cancer malignancy in the hypoxic tumor microenvironment. Herein, we report the inhibitory activity of ILs on the HIF-1α pathway and their mechanism of action. Substitution of a dimethylamino group on pyridinium reduced hypoxia-induced HIF-1α activation. It selectively inhibited the viability of the human colon cancer cell line HCT116, compared to that of the normal fibroblast cell line WI-38. These activities were enhanced by increasing the alkyl chain length in the pyridinium. Under hypoxic conditions, dimethylaminopyridinium reduced the accumulation of HIF-1α and its target genes without affecting the HIF1A mRNA level in cancer cells. It suppressed the oxygen consumption rate and ATP production by directly inhibiting electron transfer chain complex I, which led to enhanced intracellular oxygen content and oxygen-dependent degradation of HIF-1α under hypoxia. These results indicate that dimethylaminopyridinium suppresses the mitochondria and HIF-1α-dependent glucose metabolic pathway in hypoxic cancer cells. This study provides insights into the anticancer activity of pyridinium-based ILs through the regulation of cancer metabolism, making them promising candidates for cancer treatment.

In this study, sulfonated graphene oxide (sGO) with a large enhanced sulfonation degree of 1.65 mmol g−1 was simultaneously introduced as a highly ion conduction-activating carbonaceous filler for ionic polymer–metal composite (IPMC) actuator. The nanostructured styrenic block copolymer/sGO/ionic liquid (IL) composite membrane actuators revealed much larger actuation performance than top-ranked polyelectrolyte/IL actuators ever reported so far in terms of bending strain (0.88% under 2 V dc), initial strain rate (0.312% min−1), and charge-specific displacement (276.4 mm C−1). Moreover, SSPB/sGO/IL actuators exhibited excellent actuation performance without drawbacks of conventional IPMCs, such as back-relaxation and early loss of inner solvent. In addition, via tracking the movement of the IL's anion through energy-dispersive X-ray spectroscopy (EDS) analysis, not only the transporting behaviour of IL but also the pumping effect with solvated ion complexes inside the actuator are confirmed for the first time.

The conversion of the electrokinetic energy arising from evaporation-induced water flow through nanoporous materials has great potential for renewable energy production. In this study, we prepare a nanocapillary membrane containing both nanopores and nanochannels based on an assembly of holey graphene oxide (HGO) nanosheets, which enables water molecules to permeate and simultaneously evaporate from the nanostructure. In particular, we find that the performance of our HGO membrane-based water evaporation-induced energy harvester (WEEH) can be significantly improved by ensuring (1) a high capillary flow of water through low-friction nanochannels and (2) a high rate of evaporation, which is achieved by the presence of large nanoscale pores with a broad size distribution. Our WEEH yields a maximum voltage of 0.44 V, current of 200 nA, and output energy density of 2.2 μWh cm−2. Furthermore, the use of multiple WEEHs allows for the generation of sufficient energy to charge a 1-F supercapacitor and power a light-emitting diode (2 V × 20 mA). Thus, our proposed nanocapillary, thin-membrane-based WEEH has great practical potential for energy generation, as well as other membrane-based technologies such as water purification.

In the study, we report a novel polyimide (PI) delamination process using thermally reduced graphene oxide (rGO) and a Zinc Oxide (ZnO) photocatalyst as a De-Bonding Layer (DBL). The role of rGO was to control the adhesion force between the carrier glass and PI film. The ZnO nanoparticle (NP) was used as a photocatalyst to promote the chemical reaction between reduced graphene oxide and the atmosphere. The adhesion force was reduced safely and reproducibly between the carrier glass and the PI under ultraviolet (UV, 385 nm wavelength) irradiation environment, and the optimal rGO and ZnO NP concentration were 0.8 mg/ml and 15 mM, respectively. Finally, amorphous InGaZnO (a-IGZO) TFT was fabricated on the PI substrate with rGO/ZnO NP to confirm the effect of the UV irradiation process on the reliability of the backplane. The a-IGZO TFTs on Glass/rGO/ZnO/PI exhibit the following parameters; Vth: 0.60 ± 0.12 V, µFE: 16.60 ± 0.71 cm2/Vs, and SS: 0.31 ± 0.01. After the dry delamination, there was no significant change in the a-IGZO TFT performance (ΔµFE: 0.17 cm2/Vs, ΔVth: 0.24 V, ΔS·S: 0.00) as well as less than ΔVth less than 0.3 V under the negative/positive bias temperature stability condition (VGS=±20 V, 60 °C, and 10,000sec)).

Noble metal/metal-oxide-based hybrid gas sensors exhibit a low operating temperature, remarkable sensitivity, and fast recovery. As additives, noble metals induce a catalytic sensitization effect, which promotes charge transfer from the metal oxide to the analyte molecules, the so-called spillover mechanism. This suggests that metal catalysts can improve gas sensing performance. Herein, for the first time, non-noble metals are introduced on hybrid metal oxide/graphene fibers as sensitizers to fabricate high-performance chemiresistive sensors. The formation of metal components can be effectively controlled by annealing the metal oxide on graphene. Remarkably, compared with the corresponding metal oxide/graphene fiber sensors without metal components, the metal/metal oxide/graphene fiber sensors exhibit over a 16-fold higher response to NO2 gas as well as effective recovery characteristics. Specifically, the Cu/Cu2O/graphene and Ni/NiO/graphene fiber sensors operating at 150 °C exhibit sensitivities of 18.90 % and 0.82 %, respectively, for 5 ppm NO2 gas. The proposed strategy to achieve flexible graphene fiber chemiresistors by decorating them with non-noble metal and metal oxide nanoparticles opens a new avenue for realizing high-performance devices, such as photovoltaic devices, photocatalysts, and chemical catalysts.

Electroplating of metals on polymer materials is one of the best decorative processes for achieving low cost and light weight. However, low interfacial adhesion often limits practical utilization due to the potential peel-off behavior of metal layers. The interface between the metal layers and acrylonitrile-butadiene-styrene (ABS) substrate and its peeling mechanism are investigated as a function of etching time. Sa, the arithmetic average roughness of the unit area, and Sdr, the interfacial area ratio, are adopted instead of linear roughness, Ra, to quantify the surface profile. As the etching time increases, both Sa and Sdr for the etched ABS and corresponding metal side increase. The failure mode changes from adhesive to cohesive as the etching time increases, and the peel-off strength of the electroplated ABS exhibits a dependence on the tensile strength of the substrate. The peel-off strength of the electroplated ABS specimens increases to 8.46 N/cm after 30 min of etching time, but the interface degrades, forming inner voids. The Sdr ratio (Sdr, polymer / Sdr, plating) is proposed as a surface parameter to predict the peel-off strength of electroplated ABS and represents a new attempt to quantitatively correlate the interfacial morphology with the adhesion strength.

We investigated the growth behavior of Al2O3 using atomic layer deposition (ALD) on the surface of chemical vapor deposition (CVD)-grown graphene and graphene oxide (GO). While selective ALD growth was observed on CVD-grown graphene along defective sites, smooth and continuous films were grown on GO without selective growth. Linear growth of Al2O3 on GO was observed without a nucleation region or growth selectivity. This result indicates that the ALD film growth is more suitable for GO because of the abundant and homogeneously distributed reactive sites over its basal plane. By taking advantage of GO as an ideal substrate for the ALD growth of metal oxides, highly aligned, multiple-stacked, three-dimensional Al2O3/GO structures were fabricated, which showed much better effective gas barrier characteristics (1.73 × 10−4 g/m2day) than that exhibited by pristine single Al2O3 thin films of the same thickness.

Flexible electronic devices fabricated on plastic substrate are more desirable than rigid counterparts for future displays, lightings, or solar cells. For flexible electronics to become practical, the indium-tin-oxide (ITO) electrode should be replaced due to its brittleness, increasing cost, and chemical instability. Graphene has emerged as a promising material for flexible transparent conducting electrodes because of its unique electronic and mechanical properties with high optical transmittance. Therefore, graphene has been widely used in flexible electronic devices including light-emitting diodes (LEDs), solar cells (SCs), and field-effect transistors (FETs). However, for practical applications of graphene in flexible electronics, its limitations should also be overcome. This review describes the use of graphene in LEDs, SCs and FETs, and various strategies to overcome the deficiencies of graphene to obtain highly-efficient and stable flexible electronics. Finally, we present future prospects and suggest further directions for research on graphene-based flexible electronic devices.

The recent increase in demand for miniaturized electronics has necessitated the development of lightweight, narrow, and flexible channels with high current density as next-generation conductors. Despite the high electrical conductivity and current-carrying capacity (i.e., ampacity) of conventional metal conductors (e.g., copper and gold), their high mass density should be overcome for potential weight-critical applications. In this regard, defect-free graphene fibers (GFs) are excellent alternatives owing to their lightweight and high electroconductivity. In this study, GFs were electrothermally annealed at ~3000 K for a very short time (~50 s) via sequential continuous current injection. This treatment led to the carbonization and subsequent graphitization of the GFs, resulting in successful reparation of the structural disorder and crystalline defects of the GFs. This continuous process is advantageous for scaled production of highly electroconductive GFs. The resultant meter-scale GFs exhibit an electrical conductivity of 2721 S cm−1, maximum ampacity of 3.84 × 104 A cm−2, and specific current-carrying capacity of 4.67 × 104 A cm g−1, which are higher than the corresponding values of a commercial copper wire. This study provides a versatile and cost-effective technique for the development of advanced fibers and films as lightweight conductors for relevant applications.

Graphene has gained much attention for a wide variety of applications including optics, electronics, and energy applications due to its unprecedented physical properties. However, a cost-effective, scalable, environmentally-benign graphene production method is crucial for realizing commercial uses of graphene in emerging applications. Reduced graphene oxide can be obtained by chemical or thermal methods, which are considered to be scalable routes for the mass production of graphene. However, these methods require toxic chemicals or high energy consumption. Here, we show that highly reduced graphene oxide can be simply synthesized from a metal-assisted mechanochemical method. Addition of magnesium during mechanical ball milling results in the selective reduction of oxygen atoms in graphene oxide. Magnesium also preferentially donates electrons necessary for restoring sp2-carbon bonds. The resulting graphene oxide is highly reduced with a high C/O ratio (∼30) and its structural characteristics in powder form are similar to those of graphite. The present metal-assisted mechanochemical method is a scalable method for facile reduction of graphene oxide because the mechanical milling method used in this study is commonly employed for many metal/ceramic products in industry.

A facile strategy to control the interfacial energy at graphite-water interface is introduced by coating the hydrophobic graphite powder with a hydrophilic manganese oxide layer. This modification not only improves the aqueous dispersion stability of graphite particles, but also supplements the low lithium ion storage capacity of graphite due to the high lithium ion uptake capability of manganese oxide. A catalytic reaction between graphite particles and permanganate ions leads to the formation of MnO2 layer on the surface of graphite particles. Successively, annealing the resulting composite powder in a reducing atmosphere transforms surface MnO2 to MnO. The electrode prepared with MnO-coated graphite powder showed the specific capacitance of 402 mAh g−1 at a current density of 25 mA g−1, which is higher than that of the pristine graphite electrode (338 mAh g−1 at 25 mA g−1). In addition, the electrode exhibited outstanding charge–discharge cycling stability for 100 cycles at a current density of 100 mA g−1 without any fluctuation or abnormal increase in the capacity that is often observed in transition metal oxide-based electrodes. It also showed excellent rate capability comparable to the pristine graphite electrode.

SUMMARY Glutamate receptor auxiliary proteins control receptor distribution and function, ultimately controlling synapse assembly, maturation, and plasticity. At the Drosophila neuromuscular junction (NMJ), a synapse with both pre- and postsynaptic kainate-type glutamate receptors (KARs), we show that the auxiliary protein Neto evolved functionally distinct isoforms to modulate synapse development and homeostasis. Using genetics, cell biology, and electrophysiology, we demonstrate that Neto-α functions on both sides of the NMJ. In muscle, Neto-α limits the size of the postsynaptic receptor field. In motor neurons (MNs), Neto-α controls neurotransmitter release in a KAR-dependent manner. In addition, Neto-α is both required and sufficient for the presynaptic increase in neurotransmitter release in response to reduced postsynaptic sensitivity. This KAR-independent function of Neto-α is involved in activity-induced cytomatrix remodeling. We propose that Drosophila ensures NMJ functionality by acquiring two Neto isoforms with differential expression patterns and activities., In Brief Han et al. report that Neto-α functions on both pre- and postsynaptic sides of individual synapses at the Drosophila NMJ. Postsynaptic Neto-α regulates the organization of glutamate receptor fields, whereas presynaptic Neto-αis required for normal physiology and homeostatic plasticity., Graphical Abstract

Photocarrier (e−/h+) generation at low dimension graphene quantum dots offers multifunctional applications including bioimaging, optoelectronics and energy conversion devices. In this context, graphene quantum dots onto metal oxide electron transport layer finds great deal of attention in solar light driven photoelectrochemical (PEC) hydrogen fuel generation. The merits of combining tailored optical properties of the graphene quantum dots sensitizer with the transport properties of the host wide band gap one dimensional nanostructured semiconductor provide a platform for high charge collection which promotes catalytic proton reduction into fuel generation at PEC cells. However, understanding the underlying mechanism of photocarrier transfer characteristics at graphene quantum dots/metal oxide interface during operation is often difficult as graphene quantum dots may have a dual role as sensitizer and catalyst. Therefore, exploring photocarrier generation and injection at graphene quantum dot/metal oxide heterointerfaces in contact with hole scavenging electrolyte afford a new pathway in developing graphene quantum dots based photoelectrochemical fuel generation systems. In this work, we demonstrate direct assembly of surface modified graphene quantum dots (∼2 nm particle size) onto TiO2 hollow nanowire (∼3 μm in length and ∼100 to 250 nm in diameter) by electrostatic attraction and examine the photocarrier accumulation and recombination processes leading to device operation. Optical characterization reveals that GQDs absorbed light photons at visible light wavelength up to 600 nm. Hybrid TiO2-GQDs heterostructures show a photocurrent enhancement of ∼70% for water oxidation compared to pristine TiO2 using sacrificial-free electrolyte, which is further validated by incident photon to current efficiency. Additionally, the charge accumulation processes and charge transfer characteristics are investigated by electrochemical impedance spectroscopy. These results provide the platform to understand the insights of graphene quantum dots/metal oxide interfaces in PEC reactions and discuss the feasibility of graphene quantum dots in wide range of electrochemical and photoelectrochemical based fuel conversion devices.

Since the introduction of dye-sensitized solar cells (DSSCs) with low fabrication cost and high power conversion efficiency, extensive studies have been carried out to improve the charge transfer rate and performance of DSSCs. In this paper, we present DSSCs that use surface modified fluorine-doped tin oxide (FTO) substrates with reduced graphene oxide (r-GO) sheets prepared using the Langmuir–Blodgett (LB) technique to decrease the charge recombination at the TiO 2 /FTO interface. R-GO sheets were excellently attached on FTO surface without physical deformations such as wrinkles; effects of the surface coverage of r-GO on the DSSC performance were also investigated. By using graphene modified FTO substrates, the resistance at the interface of TiO 2 /FTO was reduced and the power conversion efficiency was increased to 8.44%.

We have discovered a methodology to realize the fabrication of flexible metal oxide film using two-dimensional (2D) nanosheets. Atomic scale titanium oxide (TiO x ) nanosheets were exfoliated from bulk TiO x powder that had a layered structure via the modified Sasaki’s method. The vacuum-assisted filtration generates films with laterally aligned TiO x nanosheets. The 2D sheet-like structure and hydrophilic nature of TiO x nanosheets enables the film consisting of TiO x nanosheets to be bendable. Also, we demonstrate the fabrication of electrochemical capacitors using this film. The mechanically flexible metal oxide film is expected to open up the possibility of fabricating flexible energy storage devices from 2D metal oxide nanosheets.

Background Early diagnosis of hepatitis C virus (HCV) infection is essential to allow appropriate treatment and prevent transmission. Objectives To evaluate the Elecsys ® Anti-HCV II assay as a routine screening assay in Asia using a large number of samples from different Asian Pacific populations and compare its performance with other HCV assays routinely used in the region. Study design The sensitivity and specificity of the Elecsys ® Anti-HCV II assay were determined using routine hospital samples and compared with at least one of the following comparator assays at nine independent centers: ARCHITECT™ Anti-HCV; Serodia ® -HCV Particle Agglutination; Vitros ® ECi Anti-HCV; Elecsys ® Anti-HCV; ADVIA Centaur ® HCV; InTec ® HCV EIA; or Livzon ® Anti-HCV. Commercially available seroconversion panels were used to assess sensitivity for early detection of infection. Results The Elecsys ® Anti-HCV II assay was more sensitive in recognizing early infection and detected acute HCV infection earlier on average than the comparator assays for all six panels tested. 7,726 routine samples were tested and 322 identified as HCV positive. Elecsys ® Anti-HCV II had a sensitivity of 100% and a specificity of 99.66%, both of which were comparable or superior to the results obtained for competitor assays, which ranged from 87.5–100% and 98.98–100%, respectively. Conclusions The Elecsys ® Anti-HCV II assay has the sensitivity and specificity to support its use as a routine screening method in the Asia Pacific region. Furthermore, this assay shortens the diagnostic window between infection and the detection of antibodies compared with established methods.

Unstable nature against moisture is one of the major issues of metallic halide perovskite solar cell application. Thin-film encapsulation is known as a powerful approach to notably enhance the operational stability of perovskite solar cells in humid environment. However, encapsulation layers with ideal gas barrier performance always require harsh fabrication conditions with high temperature and harmful precursors. For this reason, here we provide a mild encapsulation strategy to maintain the original performance of solar cell devices by utilization of ethylene glycol-induced immediate layer to minimize the damage of plasma-enhanced atomic layer deposition to perovskite solar cells. The organic-inorganic alternating encapsulation structure has exhibited a water vapor transmittance rate of 1.3 × 10−5 g m−2·day−1, which is the lowest value among the reported thin film encapsulation layers of perovskite solar cells. Our perovskite solar cells have survived at 80% relative humidity and 30 °C for over 2000 h while preserving 96% of its initial performance.

In solution-processed zinc tin oxide (ZTO) dual-active-layer (DAL) thin-film transistors (TFTs), a thermal limitation exists whereby the ZTO channel layer requires a high annealing temperature—above 470 °C—to achieve stable performance. This disadvantage has been overcome by applying ZnO/SnO2 channel structures and additional annealing methods. However, these methods are expensive due to equipment requirements. Therefore, we aimed at lowering the annealing temperature of solution-processed ZnO/SnO2 TFTs by varying the molar ratio and annealing conditions of the channel layers. The optimized TFTs were fabricated at an annealing temperature of 350 °C without employing additional annealing methods. The fabricated TFTs showed superior and more stable performance as compared to ZTO TFTs annealed at 350 °C. The electrical characteristics of the fabricated ZnO/SnO2 TFTs included a saturation mobility (µsat) of 3.04 cm2/V·s, an on-off-current ratio (ION/OFF) of 1.41 × 106, a threshold voltage (Vth) of 3.04 V, and a subthreshold swing (SS) of 1.49 V/dec. Based on X-ray photoelectron spectroscopy results, compared with the ZTO DAL channel layer, the ZnO/SnO2 channel layer showed an increased ratio of metal-oxygen bonds and a decreased ratio of metal-hydroxyl bonds in O 1s deconvolution peaks.

The diurnal rhythm of the autonomic function is known to be blunted in heart failure, but the timing of this blunting is not well understood. We examined the time course of the alterations in autonomic function in rats with myocardial infarction (MI) by analyzing heart rate variability (HRV). MI was induced by coronary artery ligation, and HRV was analyzed at 2, 4, 6, and 8 weeks post-MI. Diurnal rhythm in heart rate (HR) was maintained over the study period. However, diurnal rhythm in the standard deviation of averages of normal R-R intervals (SDANN) and the ratio between low and high frequency band powers (LF/HF ratio) were disrupted in MI rats at 2 weeks, which persisted up to 8 weeks, with the exception of 4 weeks. The dark-light differences in the LF/HF ratio changed from negative to positive values between weeks 2 and 4 in the MI rats. We also found decreases in HR, SDANN, and the LF/HF ratio in the dark phase at weeks 6 and 8 and an increase in plasma norepinephrine (NE) level at week 8. Collectively, the results indicate that the timing of the disturbance of diurnal rhythm in SDANN and the LF/HF ratio is different from those in HR and in plasma NE level, suggesting that the mechanisms underlying these changes are different. In addition, there is a transition from the compensatory to the decompensatory phase between 4 and 6 weeks post-MI. These findings may help to understand the progression and pathophysiology of heart failure.

Hybrid optical network-on-chip (HONoC) is a promising alternative to all-electrical NoC whose capability in the performance and the power consumption is facing ultimate physical limitation. However, the latency unfairness problem and the associated performance degradation due to the circuit switched characteristic of HONoC must be resolved. In this paper, we propose a new shortest path adaptive routing technique for HONoC by exploiting an elaborate rollback scheme and a rapid flow control method to promote the fast routing path setup and the parallel data transfers. Compared to existing works, experimental results show reduction by 41.6% in latency and improvement by 16.9% in throughput with negligible extra energy consumption. Additional benefits in the network resource utilization and the performance under increasing network sizes are also analyzed.

Background Human parechoviruses (HPeVs) have recently been recognized as important viral pathogens causing sepsis-like illness and meningitis in children, but the data on these infections in Korea is limited. Klassevirus is emerging as a novel etiologic agent of acute gastroenteritis, but its role in meningitis remains unclear. Objectives To understand the epidemiology of HPeVs and klassevirus in sepsis-like illness and meningitis through the detection and typing of the virus in cerebrospinal fluid (CSF) samples. Study design One hundred and eighty-three CSF samples collected from 183 patients ranging in the age group 1 day to 15 years were tested by using a RT-PCR assay for HPeV, EV and klassevirus. Amplification products of the VP3/VP1 and 3D region of the HPeV, and VP1 region of the EV were sequenced to identify the type. Results A total of 12 HPeV positive samples (6.5%) were detected from 183 CSF samples and all the samples were typed as HPeV-3. EVs were detected in 39 patients (21.3%) in which echovirus 25 and CVA6 were frequently detected, but mixed infection of HPeV-3 and EV was not observed. Klassevirus was not detected in the study population. Most of the HPeV-3 positive patients were under 3 months of age. HPeV-3 infection was detected mostly in the summer season. The VP3/VP1 gene of the 12 Korean strains clustered most closely to the Japan strain (AB759192) and the 3D gene of the Korean strains also clustered to the Japan strain, which showed no evidence of recombination. Conclusions To our knowledge, this is the first report on the detection of HPeV-3 from CSF samples in Korea, which suggests the necessity of routine screening for this virus in young infants with sepsis-like illness and meningitis.

The flux-lock type superconducting fault current limiter (SFCL) can quickly limit the fault current shortly after the short circuit occurs and recover the superconducting state after the fault removes. However, the superconducting element comprising the flux-lock type SFCL can be destructed when the high fault current passes through the SFCL. Therefore, the countermeasure to control the fault current and protect the superconducting element is required. In this paper, the flux-lock type SFCL with an isolated transformer, which consists of two parallel connected coils on an iron core and the isolated transformer connected in series with one of two coils, was proposed and the short-circuit experimental device to analyze the fault current limiting and the recovery characteristics of the flux-lock type SFCL with the isolated transformer were constructed. Through the short-circuit tests, the flux-lock type SFCL with the isolated transformer was confirmed to perform more effective fault current limiting and recovery operation compared to the flux-lock type SFCL without the isolated transformer from the viewpoint of the quench occurrence and the recovery time of the SFCL.

In this paper, the transformer type superconducting fault current limiter (SFCL) with two triggering current levels was suggested and its current limiting characteristics were analyzed. The structure of the suggested transformer type SFCL with two triggering current levels largely consists of two parts. One is the transformer with two magnetically coupled coils, which correspond to the primary winding and the secondary one connected with one high-TC superconducting (HTSC) element. The other is third coil, or, another secondary winding with one HTSC element, which is wound on the same iron core together with two coils. This suggested transformer type SFCL can limit the fault current by generating its limiting impedance with two different amplitudes, which are dependent on the initial amplitude of the fault current in case of the fault occurrence. To confirm the usefulness of the proposed SFCL, the current limiting tests of the SFCL according to the fault angle, one of the effective fault conditions to affect the amplitude of the initial fault current, were carried out and its effective limiting operations were discussed.

Adenosine is an inhibitory modulator of neuronal transmission, including GABAergic transmission in the hypothalamus. It is known that the local GABAergic inputs tonically inhibit the hypothalamic paraventricular neurons projecting to the rostral ventrolateral medulla (RVLM; PVN-RVLM neurons) which regulate sympathetic outflow. In this study, we examined the effects of adenosine on GABAergic synaptic transmission in the PVN-RVLM neurons using whole cell patch-clamp combined with the retrograde labeling technique. Adenosine (100 μM) reversibly decreased the frequency of miniature IPSCs (from 3.41 ± 0.75 to 2.19 ± 0.49 Hz) in a concentration-dependent manner (IC₅₀ = 1.0 μM) without affecting the amplitude and the decay time constant of miniature IPSCs. Adenosine increased the paired-pulse ratio of evoked IPSCs from 1.19 ± 0.05 to 2.28 ± 0.09 (P

Phagocytosis of foreign pathogens by cells of the immune system is a vitally important function of innate immunity. The phagocytic response is initiated when ligands on the surface of invading microorganisms come in contact with receptors on the surface of phagocytic cells such as neutrophils, monocytes/macrophages, and dendritic cells. The complement receptor CR3 (CD11b/CD18, Mac-1) mediates the phagocytosis of complement protein (C3bi)-coated particles. Fcγ receptors (FcγRs) bind IgG-opsonized particles and provide a mechanism for immune clearance and phagocytosis of IgG-coated particles. We have observed that stimulation of FcγRs modulates CR3-mediated phagocytosis and that FcγRIIA and FcγRI exert opposite (stimulatory and inhibitory) effects. We have also determined that an intact FcγR immunoreceptor tyrosine-based activation motif is required for these effects, and we have investigated the involvement of downstream effectors. The ability to up-regulate or down-regulate CR3 signaling has important implications for therapeutics in disorders involving the host defense system.

The hypothalamus plays an important role in maintaining a homeostasis of the body against stress response. In particular, the paraventricular nucleus of the hypothalamus is a critical region for disorders related to the autonomic nervous system, such as congestive heart failure and hypertension. αB-crystallin is a family of heat shock proteins that are widely expressed in the brain, including in glial cells, astrocytes, oligodendrocytes, and neurons. Many studies have demonstrated that expression level of αB-crystallin is up-regulated and involved in protecting cells from pathological conditions. In the present study, we examined the expression and potential role of αB-crystallin in the paraventricular nucleus (PVN) regions of rats with myocardial infarction (MI). Our results demonstrate that mRNA encoding αB-crystallin and protein for both native and phosphorylate forms (Ser-59) of αB-crystallin was significantly increased in the PVN during MI.

Highly ordered, multi-dimensional dendritic nanoarchitectures were created via self-assembly of diphenylalanine from an acidic buffer solution. The self-similarity of dendritic structures was characterized by examining their fractal dimensions with the box-counting method. The fractal dimension was determined to be 1.7, which demonstrates the fractal dimension of structures generated by diffusion limited aggregation on a two-dimensional substrate surface. By confining the dendritic assembly of diphenylalanine within PDMS microchannels, the self-similar dendritic growth could be hierarchically directed to create linearly assembled nanoarchitectures. Our approach offers a novel pathway for creating and directing hierarchical nanoarchitecture from biomolecular assembly.

Basic and clinical studies have revealed that depression is frequently observed following myocardial infarction (MI). We observed changes in neurons in the subgranular zone of the hippocampal dentate gyrus (DG) 14 days after chronic cardiac ischemia. Cresyl violet staining was conducted to examine neurodegeneration. Cresyl violet-positive neurons in the hippocampus in the MI-operated group were similar to those in the sham-operated group, and Fluoro-Jade B-positive cells were not observed in either group. Next, we observed changes in cell proliferation using Ki67 and in the differentiation of neuroblasts using doublecortin (DCX) in the DG. The number of Ki67- and DCX-positive cells in the subgranular zone of the DG in the MI-operated group was significantly increased compared to that in the sham-operated group. In addition, DCX-positive processes were prominent in the MI group. These results suggest that MI may influence cell proliferation and affect neuroblast differentiation in the subgranular zone of the DG.

Activation of serotonin (5-hydroxytryptamine, 5-HT) receptors produces various autonomic and neuroendocrine responses in the hypothalamic paraventricular nucleus (PVN), including increased blood pressure and heart rate. However, the role(s) of 5-HT on the local GABA synaptic circuit have not been well understood in the PVN, where the inhibitory neurotransmitter GABA plays a key role in the modulation of sympathoexcitatory outflow. In the present study, we examined the effects of 5-HT on GABA synaptic transmission in presympathetic PVN neurons projecting to spinal cord using patch-clamp electrophysiology combined with tract-tracing techniques. Bath application of 5-HT (0.01-100 microM) reversibly decreased the frequency of spontaneous GABAergic inhibitory postsynaptic currents (sIPSC) in a concentration dependent manner (IC50, 0.07 microM), with no significant changes in the amplitudes and decay kinetics of sIPSC. The sIPSC inhibition of 5-HT was mimicked by 5-HT1A agonist, 8-OH-DPAT (8-hydroxy-2(di-n-propylamino)tetralin, 10 microM), and blocked by 5-HT1A antagonist WAY-100635 but not by 5-HT1B antagonist SB224289. 5-HT also reduced the frequency of miniature IPSC (mIPSC) (2.59+/-0.51 Hz, control vs. 1.25+/-0.31 Hz, 5-HT, n=16) in similar extent with 5-HT induced reduction of sIPSC frequency (sIPSCs, 55.8+/-6.2%, n=11 vs. mIPSCs, 52.30+/-5.85%, n=16; p>0.5). All together, our results indicate that 5-HT can inhibit presynaptic GABA release via presynaptic 5-HT1A receptors in presympathetic PVN neurons projecting to spinal cord.

The quench characteristics of high- T C superconducting (HTSC) elements in the integrated three-phase flux-lock type superconducting fault current limiter (SFCL), which consisted of HTSC elements and a three-phase flux-lock reactor wound on one iron core with the same turn’s ratio between coil 1 and coil 2 in each single phase, were investigated. In a normal condition, the magnetic flux generated in the iron core is zero because the magnetic flux generated between two coils of each single phase is canceled out. However, unlike other three-phase SFCL with three isolated iron cores, the integrated three-phase flux-lock type SFCL showed the different fault current limiting characteristics for the three-phase faults such as the single line-to-ground fault, the double line-to-ground fault, the line-to-line fault and the triple line-to-ground fault. In addition, the power burden of HTSC elements comprising the integrated three-phase flux-lock type SFCL can be decreased. In this paper, we investigated the quench characteristics of HTSC elements in the integrated three-phase flux-lock type SFCL according to three-phase ground fault types. Through the experiments for the fault current limiting characteristics of this type SFCL according to three-phase ground fault types, the quench characteristics of HTSC elements were analyzed and compared with those of three-phase resistive type SFCL.

The flux-lock type superconducting fault current limiter (SFCL) has attractive characteristics that the current limiting level can be adjusted by a winding direction and the inductance ratio between two coils. We changed the winding direction and the number of coils to compare the resistive type SFCL with the flux-lock type SFCL. The initial limiting current ( I ini ) and quench characteristic were dependent on the winding direction and the inductance ratio of two coils. As a winding number was increased from 21 to 42, I ini and quench characteristic were proportionally increased. In additive polarity winding, I ini was 10.2 A and the quench time ( T q ) was 0.53 ms, which was faster than that of a subtractive polarity winding. The consumed energy and recovery characteristics in a superconducting element showed the same tendency. Recovery characteristics in the flux-lock type SFCL were dependent on the consumed energy of a superconducting element. The recovery time was related to a heat energy and it was represented as the consuming time of the heat energy. As the heat energy was shown in H = 0.24 I 2 Rt , the recovery time was shortened in the following order: a subtractive polarity winding, a resistive type and an additive polarity winding. It was known that the recovery time was proportional to a consumed energy of a superconducting element.

The development of more selective delivery systems for cancer diagnosis and chemotherapy is one of the most important goals of current anticancer research. The purpose of this study is to evaluate various self-assembled nanoparticles as candidates to shuttle radionuclide and/or drugs into tumors and to investigate the mechanisms underlying the tumor targeting with self-assembled nanoparticles. By combining different hydrophobic moieties and hydrophilic polymer backbones, various self-assembled nanoparticles were prepared, and their in vivo distributions in tumor-bearing mice were studied by radionuclide imaging. One type of nanoparticles (fluorescein isothiocyanate-conjugated glycol chitosan (FGC) nanoparticles) exhibited highly selective tumoral localization. Scintigraphic images obtained 1 day after the intravenous injection of FGC nanoparticles clearly delineated the tumor against adjacent tissues. The mechanisms underlying the tumor targeting with self-assembled nanoparticles were investigated in terms of the physicochemical properties of nanoparticles and tumor microenvironments. FGC nanoparticles were preferentially localized in perivascular regions, implying their extravasation to tumors through the hyperpermeable tumor vasculature. The magnitude and pattern of tumoral distribution of self-assembled nanoparticles were influenced by several key factors —(i) in vivo colloidal stability: nanoparticles should maintain their intact nanostructures in vivo for a long period of time, (ii) particle size, (iii) intracellular uptake of nanoparticle: fast cellular uptake greatly facilitates the tumor targeting, (iv) tumor angiogenesis: pathological angiogenesis permits access of nanoparticles to tumors. We believe that this work can provide insight for the engineering of nanoparticles and be extended to cancer therapy and diagnosis, so as to deliver multiple therapeutic agents and imaging probes at high local concentrations.

Nano-sized vesicular systems (nanoparticles), ranging from 10 nm to 1000 nm in size, have potential applications as drug delivery systems. Successful clinical applications require the efficient intracellular delivery of drug-loaded nanoparticles. Here we describe N-acetyl histidine-conjugated glycol chitosan (NAcHis-GC) self-assembled nanoparticles as a promising system for intracytoplasmic delivery of drugs. Because N-acetyl histidine (NAcHis) is hydrophobic at neutral pH, the conjugates formed self-assembled nanoparticles with mean diameters of 150−250 nm. In slightly acidic environments, such as those in endosomes, the nanoparticles were disassembled due to breakdown of the hydrophilic/hydrophobic balance by the protonation of the imidazole group of NAcHis. Cellular internalization and drug release of the pH-sensitive self-assembled nanoparticles were investigated by flow cytometry and confocal microscopy. NAcHis-GC nanoparticles internalized by adsorptive endocytosis were exocytosed or localized in endosomes. The amount of exocytosed nanoparticles was dependent on the pre-incubation time prior to removal of free nanoparticles from the culture media. Flow cytometry and confocal microscopy showed that NAcHis-GC nanoparticles released drugs into the cytosol and cell cycle analysis demonstrated that paclitaxel-incorporated NAcHis-GC nanoparticles were effective in inducing arrest of cell growth.

Photostimulated tethered free radical reactions for the intramolecular cyclizations towards α-tetralones, N-containing α-tetralone analogues, 3,4,4a,10b-tetrahydro-2H-pyrano[3,2-c]chromen-5-ones and 2,3,4,4a,6,10b-hexahydropyrano[3,2-c]quinolin-5-one were investigated. Photolysis of the t-BuHgX/Dabco with 1-aryl-4-penten-1-ones produced α-tetralones via tert-butyl radical attacks on the terminal, followed by secondary radical attack to the aromatic ring, proton abstraction and electron transfer from the radical anion intermediate to t-BuHgX. At similar conditions, formation of N-containing α-tetralone analogues, 3,4,4a,10b-tetrahydro-2H-pyrano[3,2-c]chromen-5-ones and 2,3,4,4a,6,10b-hexahydropyrano[3,2-c]quinolin-5-one also occurs in reasonable yields.

The INK4a/ARF locus, which encodes the two distinct proteins p16(INK4a) and p14(ARF), is frequently altered in various hematological malignancies as well as in other types of cancers in humans. In this study, we surveyed tumors that had spontaneously developed in Ink4a/Arf-deficient mice with an inbred FVB/NJ genetic background. We found that an Ink4a/Arf-deficiency exerted more severe effects on the induction of hematopoietic malignancies in mice with an inbred FVB/NJ genetic background than in mice with a mixed genetic background. We also provided the evidence that this prevalence of hematopoietic malignancies in Ink4a/Arf-deficient mice is associated with the upregulated expressions of Stat5 and its transcriptional target, Bcl-x(L), both of which are involved in the regulation of hematopoiesis. These results suggest a possible implication of the Ink4a/Arf locus in the control of hematopoietic pathways by negatively regulating the Stat5-signalling pathways.

Homo-oligomerization via a coiled-coil (C-C) domain has been shown to be necessary for the promyelocytic leukemia (PML)-retinoic acid receptor-alpha (RARalpha) fusion protein to acquire oncogenic potential in acute promyelocytic leukemia. We show here that PML(DeltaC-C)-RARalpha, which contains a deletion in its C-C domain, is neither localized as characteristic microspeckles nor modified by small ubiquitin-like modifiers (SUMO). The absence of sumoylation of the DeltaC-C mutant was due to the lack of binding to Ubc9, a SUMO conjugation enzyme. The integrity of RING finger domain was also needed for both sumoylation and microspeckle formation. In GAL4-DNA tethering assays, the DeltaC-C mutant completely lost the inhibitory effect on retinoic acid (RA)-mediated transactivation. Furthermore, the expression of CD14 in U937 cells expressing the DeltaC-C mutant in response to vitamin D3 was markedly higher than in cells expressing PML-RARalpha. However, the RA-mediated induction of C/EBPbeta in cells expressing the DeltaC-C mutant was comparable to that of control cells. Thus, our results suggest that the C-C domain-associated functions of sumoylation, localization as microspeckles, and the inhibition of monocyte differentiation all contribute to the oncogenic activity of PML-RARalpha.

The expression of CD14, a monocyte receptor for the bacterial lipopolysaccharide (LPS), is upregulated during monocytic cell differentiation. Although a Sp1 site at −110 bp of the CD14 promoter was shown to be critical for activation of the promoter during the differentiation, how the Sp1 site is regulated has not been well understood. We have recently reported that expression of MEF2D protein increases during the differentiation of HL60 promyeloid cells to monocyte and that the upregulation of the protein is required for CD14 expression during the differentiation [Mol. Immunol. 36 (1999) 1209]. However, there is no obvious MEF2 binding site in the critical region of the CD14 promoter. In this study, which aimed to determine the regulatory role of MEF2D in monocytic cell differentiation, MEF2D was found to form a complex with Sp1 in U937 promyeloid cells. Transient transfection experiments showed that co-expression of MEF2D and Sp1 synergistically activated the CD14 promoter. The results support a model in which increased MEF2D protein during monocytic cell differentiation activates the CD14 promoter through interaction with Sp1.