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Notwithstanding the latest advancements in anticancer therapy, non-small cell lung cancer (NSCLC) remains a prominent contributor to cancer-associated mortality worldwide. Therefore, effective anti-cancer agents are required for the treatment of NSCLC. We previously demonstrated that the natural alkaloid evodiamine efficiently suppressed lung cancer cells and lung cancer stem-like cell populations by suppressing heat shock protein 70 (Hsp70). This finding inspired us to formulate evodiamine-based anti-cancer compounds against NSCLC. In this study, we synthesized a series of evodiamine derivatives with substitutions at the N14 position. EV206 was chosen for further study because it was the most effective among the 22 evodiamine derivatives at stopping H1299 cell growth. EV206 treatment efficiently suppressed cell viability and colony formation in both attached cells and in soft agar, even in those carrying drug resistance, by inducing apoptosis. The effectiveness of EV206 is approximately ten times greater than that of evodiamine. Normal cell viability was marginally affected by EV206 treatment. Additionally, EV206 efficiently decreased the cancer stem cell (CSC) population in the NSCLC cells. EV206 reduced the growth of H460 xenograft tumors without exhibiting toxic effects. These data implied that EV206 has the potential to be an effective Hsp70-targeting anticancer drug with low toxicity. [ABSTRACT FROM AUTHOR]

Artificial Intelligence (AI) technology is leading the fourth industrial revolution, particularly as a key element in high-performance computing, complex data analysis, and real-time decision support systems. For the advancement and efficient implementation of these AI technologies, high-performance semiconductor chip manufacturing requires the essential technology of hybrid bonding processes. Hybrid bonding minimizes the physical distance between chips, enabling high-speed data transmission and low power consumption, thereby maximizing AI chip performance. Additionally, this process facilitates chip miniaturization, reduces manufacturing complexity, and supports economical production, thus expanding the application range of AI technologies across various industries. By enabling the integration of multi-functional chips, hybrid bonding significantly improves AI applications in fields such as automotive, healthcare, and telecommunications, contributing to the advancement of the fourth industrial revolution. In this paper, Wafer-to-Wafer (W2W) hybrid bonding system is developed to solve precision degradation issues occurring during the room-temperature hybrid bonding process. Performance evaluation and experiments conducted on the bonding system, fabricated based on optimal design, confirmed high-precision bonding performance at room temperature through precise position control to be compensate position error of wafer bonding. [ABSTRACT FROM AUTHOR]

The aim of this study was to design the user experience for a head-mounted display (HMD)-based universal virtual shopping store by conducting a literature analysis and employing video ethnography techniques. Subsequently, a prototype was developed to validate the outcomes. Despite the growing trend of contactless shopping, with various brands launching virtual store platforms, these often lack the elements and experiences that users find satisfying. To address this gap, we analysed users’ offline shopping experiences using video ethnography. The insights gained informed the development of a prototype that adopts a universal design approach, incorporating key features and interface designs tailored for a virtual store environment. The prototype includes innovative features include tutorials, avatar-based virtual fitting, user location/orientation control, and voice guidance. It also incorporates design features such as colour customisation, high contrast, central interface placement, and visual cues for differentiating product types. To validate the prototype’s usability, a study was conducted with 30 university students in their 20s (mean age 23.3 years, SD = 1.8), revealing high levels of satisfaction with its functionality and interface design. Further, in-depth interviews revealed that the appropriate design of features and interfaces, aligned with shopping goals and intentions, significantly enhanced interest in and engagement with virtual shopping. The prototype’s key features, representative of the main outcomes of this study, provide valuable insights for the future development of related services. [ABSTRACT FROM AUTHOR]

Introduction: This study is a retrospective case series to compare the accuracy of the Barrett toric calculator using predicted posterior corneal astigmatism (PCA) and PCA measurements using swept-source optical coherence tomography (SS-OCT) and a Scheimpflug camera. This evaluation was conducted across different types of anterior and posterior astigmatism. Methods: A total of 146 eyes from 146 patients implanted with toric intraocular lenses were included. Mean absolute prediction error, standard deviation of prediction error, and the percentage of eyes with prediction errors within ±0.50 diopters (D) were calculated using vector analysis. Biometric measurements were conducted using the IOLMaster 700 and Pentacam HR. A subgroup analysis was conducted based on the orientation of both anterior and posterior corneal astigmatism. Results: The Barrett toric calculator with predicted PCA yielded the best results, with 78.1% having a prediction error ≤ 0.50 D, which was a significantly higher percentage than the Barrett formula with the two versions of measured PCA (P < 0.05). In the subgroup with a horizontally steep meridian PCA using the IOLMaster 700, the Barrett formula with predicted PCA yielded the best results, with 78.3% of cases having a prediction error of less than 0.5 D. This percentage was significantly higher than the other two measured PCA subgroups (P < 0.05). Conclusion: The Barrett toric formula with predicted PCA demonstrated a statistically significantly higher proportion of cases with a prediction error ≤ 0.5 D compared to the two measured PCA formulas (from the IOLMaster 700 or Pentacam). This trend persisted even when the posterior corneal astigmatism was horizontally steep. [ABSTRACT FROM AUTHOR]

Out of practicality, ambient air rather than oxygen is preferred as a fuel in electrochemical systems, but CO2 and H2O present in air cause severe irreversible reactions, such as the formation of carbonates and hydroxides, which typically degrades performance. Herein, we report on a Na-air battery enabled by a reversible carbonate reaction (Na2CO3·xH2O, x = 0 or 1) in Nasicon solid electrolyte (Na3Zr2Si2PO12) that delivers a much higher discharge potential of 3.4 V than other metal-air batteries resulting in high energy density and achieves > 86 % energy efficiency at 0.1 mA cm−2 over 100 cycles. This cell design takes advantage of moisture in ambient air to form an in-situ catholyte via the deliquescent property of NaOH. As a result, not only reversible electrochemical reaction of Na2CO3·xH2O is activated but also its kinetics is facilitated. Our results demonstrate the reversible use of free ambient air as a fuel, enabled by the reversible electrochemical reaction of carbonates with a solid electrolyte. Metal-air batteries, operated in ambient air, suffer from irreversible redox reactions, limiting their energy density. Herein, the authors present a solid electrolyte-based sodium-air battery with a reversible carbonate reaction, facilitated by the in-situ formed catholyte enabled by moisture. [ABSTRACT FROM AUTHOR]

Digital clusters have been adopted as displays in vehicles, and various driving information is presented through the digital clusters with different colors. However, drivers with color vision deficiency (CVD) face difficulties in recognizing the information conveyed through color, which might lead to serious traffic accidents. In this paper, the usability of symbols in automobile digital clusters was evaluated from the perspective of people with CVD, and alternative designs were proposed and validated to improve recognition of the symbols. Twenty-seven participants with CVD and twenty-one participants with normal color vision (NCV) were recruited to investigate the influence of design elements, such as symbol color, stroke width, cluster background color, and adjacent symbol color. The choice reaction time and error rate were measured, and the perceived importance and visibility were collected using a questionnaire. As a result, the following four effects of symbol designs on the usability and recognition were identified: (1) if the existing color profile for symbols is applied, the symbol recognition was improved by modifying symbol design elements (e.g., stroke width); (2) For the symbol stroke width, a stroke width-to-height ratio of 0.12 or more was recommended; (3) Gray color is recommended for the background color, but lighting a red symbol on a gray background should be avoided for the participants with CVD; (4) When presenting a symbol adjacent to another one, presenting in red-red, green-green, orange-red, and orange-green combinations should be avoided. The results of this study can be used as reference materials when developing vehicle display interfaces that are accessible to all users including people with CVD. [ABSTRACT FROM AUTHOR]

Exposure to phthalates has been shown to impede the human endocrine system, resulting in deleterious effects on pregnant women and their children. Phthalates modify DNA methylation patterns in infant cord blood. We examined the association between prenatal phthalate exposure and DNA methylation patterns in cord blood in a Korean birth cohort. Phthalate levels were measured in 274 maternal urine samples obtained during late pregnancy and 102 neonatal urine samples obtained at birth, and DNA methylation levels were measured in cord blood samples. For each infant in the cohort, associations between CpG methylation and both maternal and neonate phthalate levels were analyzed using linear mixed models. The results were combined with those from a meta-analysis of the levels of phthalates in maternal and neonatal urine samples, which were also analyzed for MEOHP, MEHHP, MnBP, and DEHP. This meta-analysis revealed significant associations between the methylation levels of CpG sites near the CHN2 and CUL3 genes, which were also associated with MEOHP and MnBP in neonatal urine. When the data were stratified by the sex of the infant, MnBP concentration was found to be associated with one CpG site near the OR2A2 and MEGF11 genes in female infants. In contrast, the concentrations of the three maternal phthalates showed no significant association with CpG site methylation. Furthermore, the data identified distinct differentially methylated regions in maternal and neonatal urine samples following exposure to phthalates. The CpGs with methylation levels that were positively associated with phthalate levels (particularly MEOHP and MnBP) were found to be enriched genes and related pathways. These results indicate that prenatal phthalate exposure is significantly associated with DNA methylation at multiple CpG sites. These alterations in DNA methylation may serve as biomarkers of maternal exposure to phthalates in infants and are potential candidates for investigating the mechanisms by which phthalates impact maternal and neonatal health. [ABSTRACT FROM AUTHOR]

α,β-Unsaturated ketones are common feedstocks for the synthesis of fine chemicals, pharmaceuticals, and natural products. Transition metal-catalysed hydroacylation reactions of alkynes using aldehydes have been recognised as an atom-economical route to access α,β-unsaturated ketones through chemoselective aldehydic C–H activation. However, the previously reported hydroacylation reactions using rhodium, cobalt, or ruthenium catalysts require chelating moiety-bearing aldehydes to prevent decarbonylation of acyl-metal-hydride complexes. Herein, we report a nickel-catalysed anti-Markovnikov selective coupling process to afford non-tethered E-enones from terminal alkynes and S-2-pyridyl thioesters in the presence of zinc metal as a reducing agent. Utilization of a readily available thioester as an acylating agent and water as a proton donor enables the mechanistically distinctive and aldehyde-free hydroacylation of terminal alkynes. This non-chelation-controlled approach features mild reaction conditions, high step economy, and excellent regio- and stereoselectivity. Transition metal-catalysed hydroacylation of alkynes using aldehydes is an atom-economical route to access α,β-unsaturated ketones, but typically requires aldehydes that bear chelating moieties. Here, the authors report a nickel-catalysed anti-Markovnikov selective coupling process to afford non-tethered E-enones from terminal alkynes and S-2-pyridyl thioesters. [ABSTRACT FROM AUTHOR]

An experimental investigation of serpentine design flow channel heat sinks has been carried out to assess their suitability for the thermal management of high voltage direct current (HVDC) devices. This study contributes to the effective cooling technique that utilizes the mixture of water (70%) and propylene glycol (30%) as a working fluid. Fluid flow and heat transfer characteristics are significantly affected by the geometrical parameters of the flow channels in heat sink which are experimentally investigated in this study. The effects of coolant flow rate and four different flow channel shapes on the heat sink performance are investigated in detail. The assessment of heat sink performance for HVDC device is based on several exclusive attributes such as temperature profile, Nusselt number, thermal resistance, pressure drop, pumping power, Colburn j-factor, and friction factor. We conclude that the flow channel with vortex generator installed heat sink shows the best performance in contrast to other types of flow channel heat sinks studied. The proposed experimental approach provides comprehensive insights into flow channel design configurations for heat sinks. [ABSTRACT FROM AUTHOR]

Experiments on two cavitation bubbles, which are generated at the same instant, with three different sizes near solid wall are conducted and their impulses on the boundary are registered by polyvinylidene fluoride (PVDF) sensor. Due to being near the boundary, bubble interactions and deformed features are in contrast with those in infinite fluid medium. In this paper, five morphologies of bubble deformation during growth and collapse phases are observed by high-speed camera. These profiles are strongly influenced by inter-bubble distance (η), stand-off distance from boundary (γ), and bubble size differences. Analysis of photographs coupled with sensor measurements enabled qualitative investigation of two bubble interactions on the boundary. From sensor data acquisition, it is confirmed that lower bigger bubble with upper smaller bubble configuration produces highest impulses on the boundary compared with other vertical arrangements of the tandem cavitation bubble employed in this study. [ABSTRACT FROM AUTHOR]

This correction notice is for an article titled "Accuracy of Toric Intraocular Lens Calculators with Predicted and Measured Posterior Corneal Astigmatism Across Different Types of Astigmatism" published in the journal Ophthalmology & Therapy. The correction addresses an error in the funding information section of the original article. The corrected statement clarifies that the research was supported by the Korean Fund for Regenerative Medicine grant funded by the Korean government, and not the National Research Foundation as previously stated. The authors funded the journal's Rapid Service fee. The original article has been corrected. [Extracted from the article]

Conventional synthetic methods to yield polycyclic heteroarenes have largely relied on metal-mediated arylation reactions requiring pre-functionalised substrates. However, the functionalisation of unactivated azines has been restricted because of their intrinsic low reactivity. Herein, we report a transition-metal-free, radical relay π-extension approach to produce N-doped polycyclic aromatic compounds directly from simple azines and cyclic iodonium salts. Mechanistic and electron paramagnetic resonance studies provide evidence for the in situ generation of organic electron donors, while chemical trapping and electrochemical experiments implicate an iodanyl radical intermediate serving as a formal biaryl radical equivalent. This intermediate, formed by one-electron reduction of the cyclic iodonium salt, acts as the key intermediate driving the Minisci-type arylation reaction. The synthetic utility of this radical-based annulative π-extension method is highlighted by the preparation of an N-doped heptacyclic nanographene fragment through fourfold C–H arylation. The functionalisation of unactivated azines has been restricted because of their intrinsic low reactivity. Here the authors show a transition-metal-free, radical relay π-extension approach to produce N-doped polycyclic aromatic compounds directly from simple azines and cyclic iodonium salts. [ABSTRACT FROM AUTHOR]

For a reliable design of a thermal system with oil, which shows drastic change of material properties under low temperature condition, an improved prediction model is necessary because conventional correlations have limited applicability. In this paper, a numerical study on a single and concentric pipes was conducted with i) hydrodynamically fully developed and ii) uniform velocity profiles. Under a low inlet temperature condition, the fully developed velocity profile produced a z-shaped Nusselt number variation with the inverse Graetz number due to the velocity reset and re-developing mechanism. In contrast, the uniform velocity profile showed a large Nusselt number in the entrance region compared to the conventional correlation. Additionally, the simulations were carried out for parallel and counter flow arrangements. Then the Nusselt number correlations were suggested, using a sigmoidal function to reflect the z-shaped pattern. Finally, calculated friction factors were summarized and compared with the conventional correlations. [ABSTRACT FROM AUTHOR]

Purpose: We analyzed the effectiveness of insulin for treating hyperkalemia (≥ 5 mEq/L) during anesthesia and the effects of the estimated glomerular filtration rate (eGFR) and diabetes mellitus (DM) on the insulin treatment. Methods: Patients 18 years of age and older who received intravenous insulin lispro for hyperkalemia under general anesthesia between January 2010 and March 2020 were enrolled. We performed three propensity score matching analyses according to eGFR stages (eGFR ≥ 60 vs. 30 ≤ eGFR < 60 and eGFR ≥ 60 vs. eGFR < 30 mL/min/1.73 m2) and DM status. Results: The study included 475 patients. For patients with hyperkalemia during surgery, the odds ratios [ORs] of failure to decrease potassium (K+) after insulin treatment were higher in patients with eGFR < 30 mL/min/1.73 m2 (adjusted OR 3.24; 95% confidence interval 1.38–7.64; P = 0.007) than in patients with eGFR ≥ 60 mL/min/1.73 m2. There was no significant difference in the ORs of patients with 30 ≤ eGFR < 60 mL/min/1.73 m2 and DM. Conclusion: The patients with a low eGFR had a higher incidence of K+ not decreasing after insulin treatment. Periodic assessment of K+ may be required during anesthesia. [ABSTRACT FROM AUTHOR]

A self-seeded X-ray free-electron laser (XFEL) is a promising approach to realize bright, fully coherent free-electron laser (FEL) sources in the hard X-ray domain that have been a long-standing issue with longitudinal coherence remaining challenging. At the Pohang Accelerator Laboratory XFEL, we have demonstrated a hard X-ray self-seeded XFEL with a peak brightness of 3.2 × 1035 photons s–1 mm–2 mrad–2 0.1% bandwidth (BW)–1 at 9.7 keV. The bandwidth (0.19 eV) is about 1/70 times as wide (close to the Fourier transform limit) and the peak spectral brightness is 40 times higher than in self-amplified spontaneous emission (SASE), with substantial improvements in the stability of self-seeding and noticeably suppressed pedestal effects. We could reach an excellent self-seeding performance at a photon energy of 3.5 keV (lowest) and 14.6 keV (highest) with the same stability as the 9.7 keV self-seeding. The bandwidth of the 14.6 keV seeded FEL was 0.32 eV, and the peak brightness was 1.3 × 1035 photons s–1 mm–1 mrad–1 0.1%BW–1. We show that the use of seeded FEL pulses with higher reproducibility and a cleaner spectrum results in serial femtosecond crystallography data of superior quality compared with data collected using SASE mode. A hard X-ray self-seeded X-ray free-electron laser at the Pohang Accelerator Laboratory provides X-ray pulses with peak brightness of 3.2 × 1035 photons s–1 mm–2 mrad–2 0.1%BW–1 at 9.7 keV and a very small shot-to-shot electron energy jitter of 0.012%. [ABSTRACT FROM AUTHOR]

A cavitating venturi in the auxiliary feed water system of a nuclear power plant is a flow control device that limits the maximum flow rate in critical conditions. In this research, a numerical study was conducted to predict the characteristics of the cavitating flow in a venturi with various geometrical configurations. Assuming axisymmetric geometry and a steady state, equations of the flow field were solved numerically. The mixture model for the multi-phase flow and the standard k-ε turbulence model were adopted. The primary diffuser angle was varied to perform detailed parametric study. The flow and pressure variations, shape of the cavitation bubble, and corresponding flow control characteristics were summarized. Finally, the calculation results were analyzed to provide a physical basis for the design limits proposed in a previous patent. It is expected that the results of this study will be useful information for the future design of an optimized venturi. [ABSTRACT FROM AUTHOR]

In the present study, an improved heat exchanger model is proposed to efficiently analyze the cold oil removal process inside a fuel-cooled oil cooler. When exposed to low temperature condition, oil within a heat exchanger begins to congeal, preventing oil flow and causing loss of cooling. The conventional heat exchanger models, however, shows limits in reflecting the highly varying viscosity effects due to large temperature difference. To overcome this, the conventional porous media model was rewritten with the friction and Colburn j-factors that include the temperature dependent property variation. The property correction method by Shah and Sekulic [31] was added to enhance the prediction accuracy. Also, a relief valve model based on the porous media approximation is developed. The developed models were validated against the experimental data. Transient three-dimensional numerical simulations are carried out to analyze the effects of operating conditions on de-congealing phenomenon inside the FCOC. [ABSTRACT FROM AUTHOR]

This work addresses the derivation of hierarchical porous carbon material from waste biomass of spent coffee ground (SCG) via a facile pyrolysis/activation process, where the calcination of wet SCG at 800 °C induced pore development, which is attributed to the intrinsic moisture in raw SCG. Further treatment using a HNO3 and H2O2 solution at 80 °C resulted in a hierarchical pore structure of micro- and meso-pores in the carbon material with a high surface area of 1037.52 m2/g. Nitrogen, a rich heteroatom in raw SCG, is self-incorporated well in the carbon skeleton of the resultant porous carbon with a high nitrogen content of 3 w/w%. The prepared hierarchical porous carbon was tested as a material for Li–S batteries, and displayed a capacity of more than 600 mAh g−1 at 0.2 C up to 150 cycles. As a sustainable carbon material, the SCG derived porous carbon, which has abundant heteroatoms of O and N, can be employed as a potential energy storage material. [ABSTRACT FROM AUTHOR]

Background: Environmental exposure and genotype variation influence DNA methylation. Studies on the effects of genotype variation were performed mainly on European ancestries. We analyzed the genetic effects on cord blood methylation of Koreans. Methods: As part of the Korean Exposome study project, DNA was extracted from 192 cord blood samples for analysis. Cord blood samples were genotyped via Asian Precision Medicine Research Array analysis and methylation was measured using the Methylation EPIC Beadchip kits. The associations between genotypes and CpG methylation were analyzed with matrix eQTL. Results: Conditional analysis revealed 34,425 methylation quantitative trait loci (mQTLs), and trans-mQTLs constituted 7.2% of all the associated CpG sites. About 80% of the total trans-associations were trans-chromosomal and the related SNPs were concentrated on chromosome 19. According to the results of DAVID, cis-mQTL-related SNPs resulting in amino acid substitutions were related to signal peptides or glycosylation. Conclusion: We identified genotype variations associated with DNA methylation in the cord blood obtained from Koreans. [ABSTRACT FROM AUTHOR]

Chlorine evolution reaction (CER) is a critical anode reaction in chlor-alkali electrolysis. Although precious metal-based mixed metal oxides (MMOs) have been widely used as CER catalysts, they suffer from the concomitant generation of oxygen during the CER. Herein, we demonstrate that atomically dispersed Pt−N4 sites doped on a carbon nanotube (Pt1/CNT) can catalyse the CER with excellent activity and selectivity. The Pt1/CNT catalyst shows superior CER activity to a Pt nanoparticle-based catalyst and a commercial Ru/Ir-based MMO catalyst. Notably, Pt1/CNT exhibits near 100% CER selectivity even in acidic media, with low Cl− concentrations (0.1 M), as well as in neutral media, whereas the MMO catalyst shows substantially lower CER selectivity. In situ electrochemical X-ray absorption spectroscopy reveals the direct adsorption of Cl− on Pt−N4 sites during the CER. Density functional theory calculations suggest the PtN4C12 site as the most plausible active site structure for the CER. Chlorine evolution reaction (CER) is a key electrochemical reaction for chemical, pulp, and paper industries, and water treatments. Here, the authors report that an atomically dispersed Pt−N4 site can catalyse CER with high activity and selectivity under a wide range of Cl– concentrations and pH. [ABSTRACT FROM AUTHOR]

As a result of advances in sequencing technology, the role of gut microbiota in the mechanism of type-2 diabetes mellitus (T2DM) has been revealed. Studies showing wide distribution of microbiome throughout the human body, even in the blood, have motivated the investigation of the dynamics in gut microbiota across the humans. Particularly, extracellular vesicles (EVs), lipid bilayer structures secreted from the gut microbiota, have recently come into the spotlight because gut microbe-derived EVs affect glucose metabolism by inducing insulin resistance. Recently, intestine hyper-permeability linked to T2DM has also been associated with the interaction between gut microbes and leaky gut epithelium, which increases the uptake of macromolecules like lipopolysaccharide from the membranes of microbes leading to chronic inflammation. In this article, we firstly investigate the co-occurrence of stool microbes and microbe-derived EVs across serum and urine in human subjects (N = 284), showing the dynamics and stability of gut derived EVs. Stool EVs are intermediate, while the bacterial composition in both urine and serum EVs is distinct from the stool microbiome. The co-occurrence of microbes was compared between patients with T2DM (N = 29) and matched in healthy subjects (N = 145). Our results showed significantly higher correlations in patients with T2DM compared to healthy subjects across stool, serum, and urine, which could be interpreted as the dysfunction of intestinal permeability in T2DM. Therefore, the significant correlation of EVs might give insight into the pathophysiological mechanisms of T2DM, as well as the role of EVs as a biomarker in the intestinal permeability of T2DM. [ABSTRACT FROM AUTHOR]

This paper presents a mission-oriented service development environment with web-based modeling tool that enable users create workflow-based service composition. This approach utilizes the ontology-based mission service model composed of mission, task, service and resource, and task/service recommendation. During developing the mission-oriented service, capability-based semantic matching and hierarchical relationship-based filtering are used for three types of recommendation. Also, we develop a modeling environment to monitor and execute the mission service application. In experiments, we have conducted on test beds in two domains such as military environment and smart building. [ABSTRACT FROM AUTHOR]

Two-dimensional numerical simulations were used to analyze the temperature-driven natural convection phenomena in a square enclosure with an inner cylinder in the Rayleigh number range of Ra =105 ~ 106. The immersed boundary method based on the finite volume method (FVM) was applied to generate and treat inner cylinders, which remained at constant high temperature with no-slip boundary condition. The cylinder remained at a constant high temperature with no-slip boundary conditions. The detailed phenomena of natural convection were investigated according to the bottom wall temperature with a cold and isothermal top walls and adiabatic side walls. The numerical solutions at a Rayleigh number of 105 reached steady state once the solutions fully converged. When the Rayleigh number increased to 106, the solution showed unsteady characteristic depending on the bottom wall temperature. In addition, the distribution of the isotherms in the lower part of the enclosure depended on the temperature variation of the bottom wall and the Rayleigh number. These effects had a significant influence on the convection structure in the lower part of the enclosure and on the corresponding heat transfer on the walls. The convection structures in the enclosure changed significantly in several cases at 106 with a high bottom wall temperature. [ABSTRACT FROM AUTHOR]

This paper presents a novel XY nano-positioning stage using a compliant parallel mechanism with small crosstalk and yaw motion. A parallel mechanism can implement multi-degree-of-freedom motion with a small footprint. However, this implies crosstalk between the motion axes. In an effort to reduce crosstalk and yaw motion, we proposed a novel flexure guide structure. The proposed stage consists of two flexure displacement amplifiers driven by piezoelectric actuators, two combined double four-bar flexure guides, and two additional parallelogram guides. To prevent the rotational deformation of one amplifier due to the transverse force of the other, we introduce an intermediate leaf spring at the output ends of the amplifiers. This new parallel mechanism is optimally designed based on an analytical model of the stage to assure small crosstalk and yaw motion. The analytical model is verified as being well-described using a finite element analysis. An XY nano-positioning stage of size 150 × 150 × 30 mm3 is fabricated following the optimal design. Experiments are carried out to verify the static and dynamic performances of the proposed XY nano-positioning stage. The proposed stage has an X and Y directional motion range of 120 μm in closed loop. The resolution of the stage is 3 nm in both the X and Y directional motions. The actual crosstalk and yaw were limited to 0.770 μm and 13.5 μrad, while in the optimal design they were estimated at 0.5 μm and 15 μrad, respectively. [ABSTRACT FROM AUTHOR]

We consider the NP-hard problem of minimizing a convex quadratic function over the integer lattice Zn. We present a simple semidefinite programming (SDP) relaxation for obtaining a nontrivial lower bound on the optimal value of the problem. By interpreting the solution to the SDP relaxation probabilistically, we obtain a randomized algorithm for finding good suboptimal solutions, and thus an upper bound on the optimal value. The effectiveness of the method is shown for numerical problem instances of various sizes. [ABSTRACT FROM AUTHOR]

The magnetically levitated system, so called maglev system, has been researched and developed with the purpose of vacuum compatibility in the semiconductor industry. In the maglev system, the back electromotive force is inevitably generated when the system moves. The back electromotive force causes force/moment disturbances. Especially, the moment disturbances have negative effect on controlling the rotational motions ( θ , θ , θ ) whose control bandwidth is low. Therefore, the back electromotive force causes rotational motion errors. The rotational motion errors should be suppressed since they prevent high speed motion of the maglev system due to the rotational motion allowance of sensors. The rotational motion errors are suppressed by compensating the back electromotive force. In this paper, the back electromotive force, the cause of the rotational motion errors, is mathematically found in terms of the mover velocity and element of force-current matrix. A maglev system without the compensation was simulated and the rotational motion errors due to back electromotive force were found. Then, a feedforward compensated system using a mathematically modeled back electromotive force was simulated. It was verified that the feedforward compensation method with the modeled equation could be useful for suppressing rotational motion errors. [ABSTRACT FROM AUTHOR]

There are technological, operational, and environmental constraints at tactical edge, which are disconnected operation, intermittent connectivity, and limited bandwidth, size, weight and power limitations, ad-hoc and mobile network, and so on. Moreover, an operational environment is highly dynamic: requirements change in response to the emerging situation, and the availability of resources needs to be updated constantly due to the factors, such as technical failures. Therefore, an efficient matching mechanism is required that considers all possible criteria to achieve a mission. In this paper, we proposed an ontology-based mission service model that consists of a mission, tasks, services, and resources, and developed a capability-based matching mechanism in tactical edge environment. In addition, we have developed a prototype that supports dynamic resource allocation during executing a mission in tactical edge. [ABSTRACT FROM AUTHOR]

Simplified epipolar geometry is proposed in this paper to accelerate monocular visual odometry for ground vehicles. The vehicles on roads or indoors exhibit planar motion locally, and such prior has been effectively utilized to speed up monocular visual odometry. However, we observed that the previous planar motion models frequently failed because their over-simplification did not accept small non-planar motion caused by abrupt bumps or camera vibration. In this paper, simplified motion models are relaxed and their corresponding algorithms for relative pose estimation are derived. Effectiveness of the proposed algorithms is demonstrated by two types of experiments: relative pose estimation with synthetic data, and monocular visual odometry with real image sequences. In the first experiment, the proposed approximated 5-point algorithm provided similar (sometimes better) accuracy to the original 5-point algorithm, but it spent almost 15 times less computing time. In the second experiment, we also observed that monocular visual odometry with our algorithm had almost 9 times faster outlier rejection than previous approaches. [ABSTRACT FROM AUTHOR]

Red ginseng marc (RGM) is generally discarded as waste, even though it contains bioactive components. Hence, this study aimed to evaluate the bioactive components and properties of RGM extracts prepared via the fermentation of Bacillus subtilis (BSRGM) and Saccharomyces cerevisiae (SCRGM). Polyphenols were not detected in non-fermented RGM (NRGM) extracts, whereas the polyphenol levels in RGM extracts significantly increased with fermentation. The BSRGM and SCRGM extracts showed significantly higher free radicals scavenging activity than those of NRGM extracts. Treatment with the fermented RGM extracts also increased IgA levels compared to that of NRGM extracts, whereas it decreased IgE production by the mesenteric lymph node, spleen, and Peyer's patch lymphocytes. These results suggest that fermented RGM extracts may ameliorate inflammation. In addition, the phenolic compounds in fermented RGM extracts may have biological activity, making fermented RGM extracts a potential natural resource that could be used in the functional foods industry. [ABSTRACT FROM AUTHOR]

Hydrogen flow during low pressure chemical vapor deposition had significant effect not only on the physical properties but also on the electrical properties of graphene. Nucleation and grain growth of graphene increased at higher hydrogen flows. And, more oxygen-related functional groups like amorphous and oxidized carbon that probably contributed to defects or contamination of graphene remained on the graphene surface at low H flow conditions. It is believed that at low hydrogen flow, those remained oxygen or other oxidizing impurities make the graphene films p-doped and result in decreasing the carrier mobility. [ABSTRACT FROM AUTHOR]

new area expansion algorithm for the localization scheme, using temporary beacons, is proposed in this paper. The effective area of the active beacons is limited by the strength of the ultrasonic signals in a noisy environment. When a mobile robot needs to move into a hazardous area or into an unstructured environment where the beacons with pre-specified position information are not available, the localization may solely rely on dead reckoning sensors such as encoders. To overcome the error accumulation by using dead-reckoning, a new scheme is developed, in this paper, in which the mobile robot carries a few temporary beacons which do not have any pre-stored position information. When the mobile robot encounters a dangerous or unstructured environment, it utilizes the temporary beacons to localize itself. An auto-calibration algorithm has been developed to provide the position information to the temporary beacons before they are used for the localization. With these temporary beacons and the auto-calibration algorithm, mobile robots can safely pass unstructured areas. The effectiveness of the temporary beacons and auto-calibration algorithm is verified through real experiments of mobile robot navigation. [ABSTRACT FROM AUTHOR]

A concurrent localization method for multiple robots using ultrasonic beacons is proposed. This method provides a high-accuracy solution using only low-price sensors. To measure the distance of a mobile robot from a beacon at a known position, the mobile robot alerts one beacon to send out an ultrasonic signal to measure the traveling time from the beacon to the mobile robot. When multiple robots requiring localization are moving in the same block, it is necessary to have a schedule to choose the measuring sequence in order to overcome constant ultrasonic signal interference among robots. However, the increased time delay needed to estimate the positions of multiple robots degrades the localization accuracy. To solve this problem, we propose an efficient localization algorithm for multiple robots, where the robots are in groups of one master robot and several slave robots. In this method, when a master robot calls a beacon, all the group robots simultaneously receive an identical ultrasonic signal to estimate their positions. The effectiveness of the proposed algorithm has been verified through experiments. [ABSTRACT FROM AUTHOR]

Serial femtosecond X-ray crystallography (SFX) has revolutionized atomic-resolution structural investigation by expanding applicability to micrometer-sized protein crystals, even at room temperature, and by enabling dynamics studies. However, reliable crystal-carrying media for SFX are lacking. Here we introduce a grease-matrix carrier for protein microcrystals and obtain the structures of lysozyme, glucose isomerase, thaumatin and fatty acid-binding protein type 3 under ambient conditions at a resolution of or finer than 2 Å. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Despite more than a century of study, the fundamental mechanisms behind solid melting remain elusive at the nanoscale. Ultrafast phenomena in materials irradiated by intense femtosecond laser pulses have revived the interest in unveiling the puzzling processes of melting transitions. However, direct experimental validation of various microscopic models is limited due to the difficulty of imaging the internal structures of materials undergoing ultrafast and irreversible transitions. Here we overcome this challenge through time-resolved single-shot diffractive imaging using X-ray free electron laser pulses. Images of single Au nanoparticles show heterogeneous melting at the surface followed by density fluctuation deep inside the particle, which is directionally correlated to the polarization of the pumping laser. Observation of this directionality links the non-thermal electronic excitation to the thermal lattice melting, which is further verified by molecular dynamics simulations. This work provides direct evidence to the understanding of irreversible melting with an unprecedented spatiotemporal resolution. Laser-matter interaction has been intensively studied in equilibrium states, but irreversible processes in a highly nonequilibrium state at nanoscales remains elusive due to experimental challenges. Here, Ihm et al. image heterogeneous melting of gold nanoparticles with nanometer and picosecond resolution. [ABSTRACT FROM AUTHOR]

Fixed-target serial femtosecond crystallography (FT-SFX) was an important advance in crystallography by dramatically reducing sample consumption, while maintaining the benefits of SFX for obtaining crystal structures at room temperature without radiation damage. Despite a number of advantages, preparation of a sample holder for the sample delivery in FT-SFX with the use of many crystals in a single mount at ambient temperature is challenging as it can be complicated and costly, and thus, development of an efficient sample holder is essential. In this study, we introduced a nylon mesh-based sample holder enclosed by a polyimide film. This sample holder can be rapidly manufactured using a commercially available nylon mesh with pores of a desired size at a low cost without challenging technology. Furthermore, this simple device is highly efficient in data acquisition. We performed FT-SFX using a nylon mesh-based sample holder and collected over 130,000 images on a single sample holder using a 30 Hz X-ray pulse for 1.2 h. We determined the crystal structures of lysozyme and glucose isomerase using the nylon mesh at 1.65 and 1.75 Å, respectively. The nylon mesh exposed to X-rays produced very low levels of background scattering at 3.75 and 4.30 Å, which are negligible for data analysis. Our method provides a simple and rapid but highly efficient way to deliver samples for FT-SFX. [ABSTRACT FROM AUTHOR]