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The spatiotemporal variations of surface air pollutants (O3, NO2, SO2, CO, and PM10) with four land-use types, residence (R), commerce (C), industry (I) and greenbelt (G), have been investigated at 283 stations in South Korea during 2002–2013, using routinely observed data. The volatile organic compound (VOC) data at nine photochemical pollutant monitoring stations available since 2007 were utilized in order to examine their effect on the ozone chemistry. The land-use types, set by the Korean government, were generally consistent with the satellite-derived land covers and with the previous result showing anti-correlation between O3 and NO2 in diverse urban areas. The relationship between the two pollutants in the Seoul Metropolitan Area (SMA) residence land-use areas was substantially different from that outside of the SMA, probably due to the local differences in vehicle emissions. The highest concentrations of air pollutants in the diurnal, weekly, and annual cycles were found in industry for SO2 and PMPM10, in commerce for NO2 and CO, and in greenbelt for O3. The concentrations of air pollutants, except for O3, were generally higher in big cities during weekdays, while O3 showed its peak in suburban areas or small cities during weekends. The weekly cycle and trends of O3 were significantly out of phase with those of NO2, particularly in the residential and commercial areas, suggesting that vehicle emission was a major source in those areas. The ratios of VOCs to NO2 for each of the land-use types were in the order of I (10.2) > C (8.7) > G (3.9) > R (3.6), suggesting that most areas in South Korea were likely to be VOC-limited for ozone chemistry. The pollutants (NO2, SO2, CO, and PMPM10 except for O3 have decreased, most likely due to the effective government control. The total oxidant values (OX = O3 + NO2) with the land-use types were analyzed for the local and regional (or background) contributions of O3, respectively, and the order of OX (ppb) was C (57.4) > R (53.6) > I (50.7) > G (45.4), indicating the greenbelt observation was close to the background.

Trapping and transport in an optical nanochannel One of the obstacles to the development of active nanosystems is the ability to controllably deliver nanoscopic matter to and within nanostructures. This paper describes the combination of near-field optical forces (such as those used in optical traps) to confine nanoscopic matter inside a liquid core-slot waveguide and photon scattering forces to transport them. The waveguide overcomes the diffraction limits of conventional optical trapping systems to manipulate objects down to tens of nanometres in scale. As the waveguide is linear, it can also manipulate extended biomolecules demonstrated by trapping and transporting DNA molecules. This paper describes the combination of near-field optical forces (such as those used in optical traps) to confine nanoscopic matter inside a liquid core-slot waveguide and photon scattering forces to transport them. The waveguide overcomes the diffraction limits of conventional optical trapping systems to manipulate objects down to tens of nanometres in scale. As the waveguide is linear, it can also manipulate extended biomolecules demonstrated by trapping and transporting DNA molecules. The ability to manipulate nanoscopic matter precisely is critical for the development of active nanosystems. Optical tweezers 1 , 2 , 3 , 4 are excellent tools for transporting particles ranging in size from several micrometres to a few hundred nanometres. Manipulation of dielectric objects with much smaller diameters, however, requires stronger optical confinement and higher intensities than can be provided by these diffraction-limited 5 systems. Here we present an approach to optofluidic transport that overcomes these limitations, using sub-wavelength liquid-core slot waveguides 6 . The technique simultaneously makes use of near-field optical forces to confine matter inside the waveguide and scattering/adsorption forces to transport it. The ability of the slot waveguide to condense the accessible electromagnetic energy to scales as small as 60 nm allows us also to overcome the fundamental diffraction problem. We apply the approach here to the trapping and transport of 75-nm dielectric nanoparticles and λ-DNA molecules. Because trapping occurs along a line, rather than at a point as with traditional point traps 7 , 8 , the method provides the ability to handle extended biomolecules directly. We also carry out a detailed numerical analysis that relates the near-field optical forces to release kinetics. We believe that the architecture demonstrated here will help to bridge the gap between optical manipulation and nanofluidics.

Blended learning combines online digital resources with traditional classroom activities and enables students to attain higher learning performance through well-defined interactive strategies involving online and traditional learning activities. Learning analytics is a conceptual framework and as a part of our Precision education used to analyze and predict students' performance and provide timely interventions based on student learning profiles. This study applied learning analytics and educational big data approaches for the early prediction of students' final academic performance in a blended Calculus course. Real data with 21 variables were collected from the proposed course, consisting of video-viewing behaviors, out-of-class practice behaviors, homework and quiz scores, and after-school tutoring. This study applied principal component regression to predict students' final academic performance. The experimental results show that students' final academic performance could be predicted when only one-third of the semester had elapsed. In addition, we identified seven critical factors that affect students' academic performance, consisting of four online factors and three traditional factors. The results showed that the blended data set combining online and traditional critical factors had the highest predictive performance.

In this study, an augmented reality-based mobile learning system is proposed for conducting inquiry-based learning activities. An experiment has been conducted to examine the effectiveness of the proposed approach in terms of learning achievements and motivations. The subjects were 57 fourth graders from two classes taught by the same teacher in an elementary school in northern Taiwan. The experimental results showed that the proposed approach is able to improve the students' learning achievements. Moreover, it was found that the students who learned with the augmented reality-based mobile learning approach showed significantly higher motivations in the attention, confidence, and relevance dimensions than those who learned with the conventional inquiry-based mobile learning approach.

Virtual reality (VR) learning environments can provide students with concepts of the simulated phenomena, but users are not allowed to interact with real elements. Conversely, augmented reality (AR) learning environments blend real-world environments so AR could enhance the effects of computer simulation and promote students' realistic experience. However, AR-based learning environments had a lot of dynamic real objects which may increase learners' mental effort. Moreover, paucity of research compared AR with VR and other mature technologies. Thus, the aim of this study is to compare the influence of the 2D image-based VR and AR in an inquiry-based astronomy course. The findings of this study suggested that the real objects presented in the AR system could reduce the mental load because students could take the real objects of the AR system as the reference objects of the movement of the moon. Furthermore, the sense of the immediacy is increased due to the fact that peers appear on the AR system. Accordingly, the real objects and the sense of the immediacy not only enhance the learning motivations, but also encourage the students to keep conducting the tasks.

In 1985 Fridriech and Wintgen proposed a mechanism for bound states in the continuum based on full destructive interference of two resonances which can be easily applied to the two- and three-dimensional wave systems. Here we explicitly show that this mechanism can be realized in one-dimensional quantum potential well, owing to destructive interference of electron paths with different spin in tilted magnetic field. Due to one-by-one correspondence between the spin of the electron and the polarization state of light, we have found numerous bound states in the continuum in the one-dimensional photonic system and experimentally confirmed them. The experimental set-up consists of the one-dimensional photonic crystal conjugated with a liquid-crystalline anisotropic defect layer and covered by metal film. Bound states in the continuum have recently found application to sensing, lasing and optoelectronics, but have not been realised in 1D. Here, destructive interference of electron spin in a tilted magnetic field is shown to give rise to bound states in the continuum of a 1D layered photonic crystal.

SummaryThe mortality risk showed a positive correlation as the number of subsequent fractures increased. Hip fracture showed the greatest association with mortality risk, followed by vertebral fracture. For the combination of hip and vertebral fracture, a hip fracture after a vertebral fracture showed the highest mortality risk.IntroductionIt is unclear whether subsequent fractures or a certain location and sequence of subsequent fractures are associated with mortality risk in the elderly. We aimed to investigate the relationship between subsequent fractures and mortality risk.MethodsUsing the Korean National Health Insurance Research Database, we analyzed the cohort data of 24,756 patients aged > 60 years who sustained fractures between 2002 and 2013. Cox regression was used to assess the mortality risk associated with the number, locations, and sequences of subsequent fractures.ResultsMortality hazard ratios (HRs) for women and men were shown to be associated with the number of subsequent fractures (one, 1.63 (95% confidence interval [CI], 1.48–1.80) and 1.42 (95% CI, 1.28–1.58); two, 1.75 (95% CI, 1.47–2.08) and 2.03 (95% CI, 1.69–2.43); three or more, 2.46(95% CI, 1.92–3.15) and 1.92 (95% CI, 1.34–2.74), respectively). For women, the mortality risk was high when hip (HR, 2.49; 95% CI, 1.80–3.44) or vertebral (HR, 1.40; 95% CI, 1.03–1.90) fracture occurred as a second fracture. Compared with a single hip fracture, there was a high mortality risk in the group with hip fracture after the first vertebral fracture (HR, 2.90; 95% CI, 1.86–4.54), followed by vertebral fracture after the first hip fracture (HR, 1.90; 95% CI, 1.12–3.22).ConclusionThe mortality risk showed a positive correlation as the number of subsequent fractures increased. Hip fracture showed the greatest association with mortality risk, followed by vertebral fracture. For the combination of hip and vertebral fracture, a hip fracture after a vertebral fracture showed the highest mortality risk.

This study developed a 5-step vocabulary learning (FSVL) strategy and a mobile learning tool in a situational English vocabulary learning environment and assessed their effects on the learning motivation and performance of English as a foreign language (EFL) students in a situational English vocabulary learning environment. Overall, 80 EFL students and 1 teacher participated in this study. Two learning methods were implemented. The first involved employing the FSVL strategy and the mobile learning tool in a situational English vocabulary learning environment, and the other method involved employing the FSVL strategy and traditional learning tools in a situational English vocabulary learning environment. Data were collected by conducting interviews and tests and administering the Attention, Relevance, Confidence, and Satisfaction motivation questionnaire. The results showed that the learning motivation and performance of students taught using the FSVL strategy and mobile learning tool were superior to those of students taught using the FSVL strategy and traditional learning tools in a situational English vocabulary learning environment.

Chimeric antigen receptor-modified T cell (CAR-T) immunotherapy has revolutionised blood cancer treatment. Parsing the genetic underpinnings of T cell quality and CAR-T efficacy is challenging. Transcriptomics inform CAR-T state, but the nature of dynamic transcription during activation hinders identification of transiently or minimally expressed genes, such as transcription factors, and over-emphasises effector and metabolism genes. Here we explore whether analyses of transcriptionally repressive and permissive histone methylation marks describe CAR-T cell functional states and therapeutic potential beyond transcriptomic analyses. Histone mark analyses improve identification of differences between naïve, central memory, and effector memory CD8 + T cell subsets of human origin, and CAR-T derived from these subsets. We find important differences between CAR-T manufactured from central memory cells of healthy donors and of patients. By examining CAR-T products from a clinical trial in lymphoma (NCT01865617), we find a novel association between the activity of the transcription factor KLF7 with in vivo CAR-T accumulation in patients and demonstrate that over-expression of KLF7 increases in vitro CAR-T proliferation and IL-2 production.  In conclusion, histone marks provide a rich dataset for identification of functionally relevant genes not apparent by transcriptomics. Transcriptomics is widely used to identify functional and developmental states of T cells and their genetically engineered therapeutic counterparts, such as CAR-T cells. Here authors show that by looking at epigenetic markers in human CD8 + T cells and CAR-T cells, properties and quality of these cells, which are not obvious from gene expression analysis, could be accurately described.