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The purpose of this article is to attempt to combine North Korean humanities research with digital humanities methods, using the North Korean Humanities Data Archive (NKHDA) project as an example, and to report on a newly constructed semantic data processing model. Although NKHDA targeted the entire scope of North Korean humanities, it mainly focused on the field of historiography, which has a relatively large accumulation of scholarly information. This article focuses on North Korean historiography to discuss the following three points. Firstly, the theoretical and technical background of the NKHDA is summarized. Secondly, the trial-and-error process of constructing NKHDA is described. Thirdly, the process of creating a new model of semantic data processing by combining wiki documentation and triple data/visualization is described. A new model was made possible by embedding triple data lists and network graphs into wiki pages and developing a data entry tool for triple data generation. Also described is the NKHDA's use as an educational platform for the digital humanities. [ABSTRACT FROM AUTHOR]

Precise control over the topology of plasmonic metal-semiconductor heteronanostructures is essential for fully harnessing their plasmonic function and hence for designing innovative solar energy conversion platforms. Here, we present a rational synthesis strategy for the realization of plasmonic metal-semiconductor heteronanocrystals with intended configurations through the site-selective overgrowth of semiconductor Cu2O on desired sites of anisotropic Au nanocrystals. Both the exploitation of structural characteristics of Au nanocrystals and the selective stabilization of their surfaces are keys to the construction of heteronanocrystals with a specific configuration. Our approach can provide an opportunity to precisely explore the link between the solar energy conversion efficiency and the structure of heteronanocrystals as well as to obtain important insights into the underpinning mechanism. Heteronanocrystals produced by Cu2O overgrowth preferentially on the multiple high-curvature sites of Au nanocrystals exhibited prominent photocatalytic hydrogen production activity due to efficient charge separation by strong plasmon excitation at the Au-Cu2O interface and subsequent sustainable hot electron transfer from Au to Cu2O. [ABSTRACT FROM AUTHOR]

We report a universal sulfide-assisted synthesis strategy to prepare dumbbell-like M-Ag heterodimers (M = Pd, Au, Pt). Sulfide ions can give fine control over the reaction kinetics of Ag precursors, resulting in the anisotropic overgrowth of Ag to realize the dumbbell-like heterodimers irrespective of the surface facets or components of the M domain. The M-Ag heterodimers were facilely transformed to M-Ag2S heterodimers via a simple sulfidation reaction. This study provides a versatile approach to realizing not only metal-metal heterodimers but also semiconductor-metal heterodimers and will pave the way for designing heteronanostructures with unprecedented morphologies and functions. [ABSTRACT FROM AUTHOR]

Au nanocrystals (NCs) with an unprecedented hexoctahedral structure enclosed exclusively by high-index {321} facets have been prepared for the first time. Manipulating the NC growth kinetics by controlling the amount of reductant and the reaction temperature in the presence of a suitable surfactant was the key synthetic lever for controlling the morphology of the Au NCs. The hexoctahedral Au NCs exhibited efficient optical and surface-enhanced Raman scattering activities due to their unique morphological characteristics. [ABSTRACT FROM AUTHOR]

Treatment of U937 cells with epidermal growth factor (EGF) induces phosphorylation of tis21 and subsequent interaction of tis21 with Pin-1, resulting in the increased cell death with mitochondrial depolarization. Ser147 and Ser149 residues of tis21 were strongly phosphorylated by p-Erk½ and p-p38MAPK, respectively, but not by JNK. To investigate the significance of phosphorylation of the Ser147 residue, Pin-1, one of the mitotic regulators that binds to the Ser(P)/Thr(P)-Pro region, was employed. Wild type tis21 phosphorylated by p-Erk½ clearly increased its binding to Pin-1, but not the P148A mutant, indicating that Pin-1 was bound to the Ser(P)147-Pro148 region of tis21. Transfection of tis21 significantly enhanced EGF-induced Pin-1 diffusion to cytoplasm, compared with that in the vector-transfected cells. Knockdown of tis21 expression by using shRNAi significantly inhibited EGF-induced Pin-1 diffusion, and analysis by flow cytometry after JC-1 stain and confocal microscope revealed that EGF aggravated tis21-induced mitochondrial depolarization and cell death. Furthermore, tis21 was bound to cyclin B1 and Cdc2 and inhibited its activity in vivo and in vitro. In summary, treatment of U937 cells with EGF activates Erk½, which in turn phosphorylates Ser147 of tis21 and induces tis21 and Pin-1 binding and mitochondrial depolarization. These data suggest, for the first time, a mechanism of how EGF can be antiproliferative in human tumor cells: binding of tis21/ BTG2/pc3 to Pin-1 or cyclin B1-Cdc2 complex and induction of mitochondrial depolarization. [ABSTRACT FROM AUTHOR]

Microfluidic chip platforms for manipulating liquid volumes in the nanoliter range are slowly inching their way into mainstream genomic and proteomic research. The principal challenge faced by these technologies is the need for high-throughput processing of increasingly smaller volumes, with ever higher degrees of parallelization. Significant advances have been made over the past few years in addressing these needs through electrokinetic manipulation, vesicle encapsulation and mechanical valve approaches. These strategies allow levels of integration density and platform complexity that promise to make them into serious alternatives to current robotic systems. [ABSTRACT FROM AUTHOR]

Bimetallic alloy Au–Pd nanoparticles with an unprecedented octapodal shape have been prepared by a one-pot aqueous synthesis method. This unique structure was produced through selective etching of {100} facets by in situgenerated Br−ions. The octapodal Au–Pd nanoparticles exhibited efficient electrocatalytic properties toward ethanol oxidation. [ABSTRACT FROM AUTHOR]

The relation between surface structure and friction and adhesion is a long-standing question in tribology. Tuning the surface structure of the exposed facets of metal nanoparticles is enabled by shape control. We investigated the effect of the shape of Au nanoparticles on friction and adhesion. Two nanoparticle systems, cubic nanoparticles with a low-index (100) surface and hexoctahedral nanoparticles with a high-index (321) surface, were used as model nanoparticle surfaces. Atomic force microscopy was used to probe the nanoscale friction and adhesion on the nanoparticle surface. Before removing the capping layers, the friction results include contributions from both the geometric factor and the presence of capping layers. After removing the capping layers, we can see the exclusive effect of the surface atomic structure while the geometric effect is maintained. We found that after removing the capping layer, the cubic Au nanoparticles exhibited higher adhesion and friction, compared with cubes capped with layers covering 25% and 70%, respectively. On the other hand, the adhesion and friction of hexoctahedral Au nanoparticles decreased after removing the capping layers, compared with nanoparticles with capping layers. The difference in adhesion and friction forces between the bare Au surfaces and Au nanoparticles with capping layers cannot be explained by geometric factors, such as the slope of the nanoparticle surfaces. The higher adhesion and friction forces on cubic nanoparticles after removing the capping layers is associated with the atomic structure of (100) and (321) (i.e., the flat (100) surfaces of the cubic nanoparticles have a larger contact area, compared with the rough (321) surfaces of the hexoctahedral nanoparticles). This study implies an intrinsic relation between atomic structure and nanomechanical properties, with potential applications for controlling nanoscale friction and adhesion via colloid chemistry. [ABSTRACT FROM AUTHOR]

The development of single site electrocatalysts such as single-atom catalyst (SAC) has demonstrated the advantages of high precious metal utilization and tunable metalsupport interfacial properties. However, the fundamental understanding of unalloyed single metal atom decorated on a metallic substrate is still lacking. Herein, we report unalloyed single atomic, partially oxidized Rh on the Pt nanocube surface as the electrocatalyst to completely oxidize ethanol to CO2 at a record-low potential of 0.35 V. In situ X-ray absorption fine structure measurements and density functional theory calculations reveal that the single-atom Rh sites facilitate the C-C bond cleavage and the removal of the *CO intermediates. This work not only reveals the fundamental role of unalloyed, partially oxidized SAC in ethanol oxidation reaction but also offers a unique single-atom approach using low-coordination active sites on shape-controlled nanocatalysts to tune the activity and selectivity toward complicated catalytic reactions. [ABSTRACT FROM AUTHOR]

In this study, electrochemical detection of acrylamide using hemoglobin (Hb)-modified core-shell Fe3O4@Au nanostructures was conducted. Fe3O4 nanoparticles (~4.9 nm) and core-shell Fe3O4@Au (5.0-6.4 nm) nanostructures were successfully synthesized by the thermal decomposition method. Electrochemical investigation revealed that the optimum amount of Hb of 2 mg/mL could be immobilized in 0.1 M acetate buffer solution (pH = 6). Moreover, the detection of acrylamide using Fe3O4@Au/Hb was evaluated by the cyclic voltammetry technique. A linear calibration curve (R² = 0.98) in the concentration range of 0.1 to 1.0 µM could be achieved with an estimated limit of detection, limit of quantification, and sensitivity of 0.136 µM, 0.453 µM, and 0.4411 µA/µM, respectively. Furthermore, the developed biosensor exhibited high selectivity in the presence of ascorbic acid, melamine, and caffeine. The developed biosensor was applied to the detection of acrylamide in coffee samples and validated using the standard high-performance liquid chromatography (HPLC) method. The concentration of acrylamide in coffee samples was determined to be 37.450 and 35.377 ppm using electrochemical measurement and HPLC, respectively. [ABSTRACT FROM AUTHOR]

Microbubbles and nanobubbles (MNBs) can be prepared using various shells, such as phospholipids, polymers, proteins, and surfactants. MNBs contain gas cores due to which they are echogenic and can be used as contrast agents for ultrasonic and photoacoustic imaging. These bubbles can be engineered in various sizes as vehicles for gas and drug delivery applications with novel properties and flexible structures. Hypoxic areas in tumors develop owing to an imbalance of oxygen supply and demand. In tumors, hypoxic regions have shown more resistance to chemotherapy, radiotherapy, and photodynamic therapies. The efficacy of photodynamic therapy depends on the effective accumulation of photosensitizer drug in tumors and the availability of oxygen in the tumor to generate reactive oxygen species. MNBs have been shown to reverse hypoxic conditions, degradation of hypoxia inducible factor 1α protein, and increase tissue oxygen levels. This review summarizes the synthesis methods and shell compositions of micro/nanobubbles and methods deployed for oxygen delivery. Methods of functionalization of MNBs, their ability to deliver oxygen and drugs, incorporation of photosensitizers and potential application of photo-triggered theranostics, have also been discussed. [ABSTRACT FROM AUTHOR]

Microfluidic devices based on the multilayer soft lithography allow accurate manipulation of liquids, handling reagents at the sub-nanoliter level, and performing multiple reactions in parallel processors by adapting micromixers. Here, we have experimentally evaluated and compared several designs of micromixers and operating conditions to find design guidelines for the micromixers. We tested circular, triangular, and rectangular mixing loops and measured mixing performance according to the position and the width of the valves that drive nanoliters of fluids in the micrometer scale mixing loop. We found that the rectangular mixer is best for the applications of highly integrated microfluidic platforms in terms of the mixing performance and the space utilization. This study provides an improved understanding of the flow behaviors inside micromixers and design guidelines for micromixers that are critical to build higher order fluidic systems for the complicated parallel bio/chemical processes on a chip. [ABSTRACT FROM AUTHOR]

A simpleway of preparing fluorescent silicon nanoparticles (SiNPs)with a mean diameter of ∼5 nm was demonstrated from used siliconwafers. Anodic etching of used wafers performed in a customized electrochemicalcell produced H-terminated, nano- and micropores on the wafer surface,and SiNPs were attained by mechanically crumbling the nano-/microporousSi surface structures on the etched wafers in an ultrasonic bath.The obtained SiNPs were then re-etched in different ratios of HF/HNO3acid mixture to produce different PL intensities, sizes,and yields. When the particle sizes were decreased by adjusting theexperimental conditions (e.g., strength of the acid mixture, reactiontime), the PL spectra from etched SiNPs were also shifted from redto blue, indicating the quantum confinement effect from the nanoparticles.Typically, blue-emitting SiNPs were observed with an average diameterof 2.7 nm and a yield of 0.3 mg/cm2of used wafers. Re-etchedSiNPs were dialyzed by a 1K-dialysis membrane for purification andfor potential use in bioapplications. The efficient method of preparingfluorescent nanoparticles from used monocrystalline Si wafers wasdemonstrated with a high production yield. The produced particlesshowed outstanding physical and chemical properties, indicating theapplicability of these materials in semiconductor research and bioapplications. [ABSTRACT FROM AUTHOR]

A systematic study of heterogeneous Buchwald--Hartwig amination using shape-controlled Pd nanocrystals with distinctly differen surface facets is presented. [ABSTRACT FROM AUTHOR]

Systematic screening of algal cells is getting huge interest due to their capability of producing lipid-based biodiesel. Here, we introduce a new microfluidic platform composed of an array of perfusion chambers designed for long-term cultivation and preliminary screening of motile microalgal cells through loading and releasing of cells to and from the chambers. The chemical environment in each perfusion chamber was independently controlled for 5 days. The effect of nitrogen-depletion on the lipid production, phototaxis behavior in the absence of Ca2+, and cytotoxic effect of herbicide on microalgal cells was successfully monitored and compared with simultaneous control experiments on the platform. The present methodology could be extended to effective screening of algal cells and various cell lines for the production of biodiesel and other useful chemicals. [ABSTRACT FROM AUTHOR]

High-throughput growth phenotyping is receiving great attention for establishing the genotype-phenotype map of sequenced organisms owing to the ready availability of complete genome sequences. To date, microbial growth phenotypes have been investigated mostly by the conventional method of batch cultivation using test tubes, Erlenmeyer flasks, or the recently available microwell plates. However, the current batch cultivation methods are time- and labor-intensive and often fail to consider sophisticated environmental changes. The implementation of batch cultures at the nanoliter scale has been difficult because of the quick evaporation of the culture medium inside the reactors. Here, we report a microfluidic system that allows independent cell cultures in evaporation-free multiplex nanoliter reactors under different culture conditions to assess the behavior of cells. The design allows three experimental replicates for each of eight culture environments in a single run. We demonstrate the versatility of the device by performing growth curve experiments with Escherichia coli and microbiological assays of antibiotics against the opportunistic pathogen Pseudomonas aeruginosa. Our study highlights that the microfluidic system can effectively replace the traditional batch culture methods with nanoliter volumes of bacterial cultivations, and it may be therefore promising for high-throughput growth phenotyping as well as for single-cell analyses. [ABSTRACT FROM AUTHOR]

Cell-based assays play a critical role in discovery of new drugs and facilitating research in cancer, immunology, and stem cells. Conventionally, they are performed in Petri dishes, tubes, or well plates, using milliliters of reagents and thousands of cells to obtain one data point. Here, we are introducing a new platform to realize cell-based assay capable of increased throughput and greater sensitivity with a limited number of cells. We integrated an array of open-well microchambers into a gradient generation system. Consequently, cell-based dose responses were examined with a single device. We measured IC50 values of three cytotoxic chemicals, Triton X-100, H2O2, and cadmium chloride, as model compounds. The present system is highly suitable for the discovery of new drugs and studying the effect of chemicals on cell viability or mortality with limited samples and cells. [ABSTRACT FROM AUTHOR]

We demonstrate the accommodation of log-scale concentration gradients of inhibitors on a single microfluidic chip with a semidirect dilution capability of reagents for the determination of the half-inhibitory concentration or IC50. The chip provides a unique tool for hosting a wide-range of concentration gradient for studies that require an equal distribution of measuring points on a logarithmic scale. Using Matrix metalloproteinase IX and three of its inhibitors, marimastat, batimastat, and CP471474, we evaluated the IC50 of each inhibitor with a single experiment. The present work could be applied to the systematic study of biochemical binding and inhibition processes particularly in the field of mechanistic enzymology and the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

We present a new methodology for generating a stepwise concentration gradient in a series of microdroplets by using monolithic micro valves that act as "faucets" in micrometer-scale. A distinct concentration gradient of a substrate was generated for the determination of the kinetic parameters of two different enzymes using only 10 picoliter-scafe droplets. With a single experiment on a chip, we obtained KM and Kcat, values of matrix metalloproteinase 2 (MMP-2) and matrix metalloproteina.se 9 (MMP-9), and compared the catalytic competence of the two enzymes. The present system and method are highly suitable for applications where the reagents or samples are limited and precious. [ABSTRACT FROM AUTHOR]

We describe a microfluidic device for generating nonlinear (exponential and sigmoidal) concentration gradients, coupled with a microwell array for cell storage and analysis. The device has two inputs for coflowing multiple aqueous solutions, a main coflow channel and an asymmetrical grid of fluidic channels that allows the two solutions to combine at intersection points without fully mixing. Due to this asymmetry and diffusion of the two species in the coflow channel, varying amounts of the two solutions enter each fluidic path. This induces exponential and sigmoidal concentration gradients at low and high flow rates, respectively, making the microfluidic device versatile. A key feature of this design is that it is space-saving, as it does not require multiplexing or a separate array of mixing channels. Furthermore, the gradient structure can be utilized in concert with cell experiments, to expose cells captured in microwells to various concentrations of soluble factors. We demonstrate the utility of this design to assess the viability of fibroblast cells in response to a range of hydrogen peroxide (H2O2) concentrations. [ABSTRACT FROM AUTHOR]