Search

An experimental study was performed to investigate the effect of external prestressed truss steel-bar units installed on an unreinforced masonry (URM) wall under out-of-plane loadings. The key components of this new retrofitting method are prestressed vertical and diagonal bars. The prestressed vertical bars induce a prestressing force onto the horizontal section of the URM wall and the diagonal bars resist lateral loadings. Reverse cyclic tests were conducted on a full-scale URM wall as a control specimen and URM walls retrofitted in-plane and/or out-of-plane (parallel to short intersecting walls). The test results showed that the specimen strengthened using the new technique was superior to the control specimen in terms of seismic performance, including lateral load resistance, stiffness, energy dissipation and restrained slip of the entire specimen. Two units installed on short intersecting walls exhibited the same shear strength as four units installed on the in-plane and in-plane retrofitted masonry walls. The out-of-plane masonry specimen demonstrated the best performance. It was confirmed that aligning the retrofitting method based on the loading direction was effective, despite the lower axial load level.

Background/aims Heme oxygenase-1 (HO-1) plays a central role in cellular defense against inflammatory insults, and its induction in macrophages potentiates their efferocytic activity. In this study, we explored the potential role of macrophage HO-1 in the resolution of experimentally induced colitis. Methods To induce colitis, male C57BL/6 mice were treated with 2% dextran sulfate sodium (DSS) in the drinking water for 7 days. To investigate efferocytosis, apoptotic colon epithelial CCD 841 CoN cells were coincubated with bone marrow-derived macrophages (BMDMs). Results Administration of the HO-1 inhibitor zinc protoporphyrin IX (ZnPP) blunted the resolution of DSS-induced intestinal inflammation and expression of the proresolving M2 macrophage marker CD206. BMDMs treated with apoptotic colonic epithelial cells showed significantly elevated expression of HO-1 and its regulator Nrf2. Under the same experimental conditions, the proportion of CD206-expressing macrophages was also enhanced. ZnPP treatment abrogated the upregulation of CD206 expression in BMDMs engulfing apoptotic colonic epithelial cells. This result was verified with BMDMs isolated from HO-1-knockout mice. BMDMs, when stimulated with lipopolysaccharide, exhibited increased expression of CD86, a marker of M1 macrophages. Coculture of lipopolysaccharide-stimulated BMDMs with apoptotic colonic epithelial cell debris dampened the expression of CD86 as well as the pro-inflammatory cytokines in an HO-1-dependent manner. Genetic ablation as well as pharmacologic inhibition of HO-1 significantly reduced the proportion of efferocytic BMDMs expressing the scavenger receptor CD36. Conclusions HO-1 plays a key role in the resolution of experimentally induced colitis by modulating the polarization of macrophages.

This study examines the flexural performance of reinforced concrete (RC) columns strengthened through a seismic jacket technique developed using a prefabricated steel bar unit that forms peripheral closed hoops and supplementary V ties, satisfying the design requirements of the ACI 318-14 seismic provisions. Three RC jacketed columns were prepared with a parameter of axial load levels and tested under a constant concentric axial load and cyclic lateral loads. Analytical approaches were also applied to examine the axial load–moment interaction of the RC jacketed columns when considering the confinement effect provided by the jacket section and to investigate the applicability of the previous performance-based design models proposed for virgin seismic columns. The test results show that the developed jacket technique possesses a good potential in enhancing the flexural stiffness, strength and ductility of deficient columns, even under a high axial load. Reinforced concrete jacketed columns possess a higher ductility than that estimated using the ductility parameter model, regardless of the axial load level. Thus, the jacket section including the seismic details of a transverse reinforcement can be conservatively designed, based on the axial load–moment interaction and ductility parameter model for the moment and ductility enhancements required by deficient columns.

To improve the stability and sensitivity of pH sensors based on AlGaN/GaN high electron mobility transistors (HEMTs), we proposed a modified sensing structure by integrating a reference HEMT device. This structural pH sensor exhibits a typical Nernstian behavior with a sensitivity of 54.38 mV/pH, which is higher than the value of 49.43mV/pH derived from the AlGaN/GaN HEMT-based sensor without integrating the reference HEMTs device. Furthermore, the stability of the new structural sensor is enhanced by approximately 19.2% in comparison with that of its traditional counterpart. The improved performances are analyzed using an electrical double-layer model together with an equivalent circuit model, and we find that the new sensor structure has a larger capacitor and exhibits a better rectification effect, hence decreasing the electrical noise and enhancing the stability of the testing signal. Meanwhile, the new sensor structure displays a smaller equivalent resistance and results in a larger available output current, hence exhibiting a higher sensitivity.

Highlights • The phagocytosis of tumor cell debris by tumor-associated macrophages reduces chemotherapeutic efficacy. • Expression of heme oxygenase-1 in tumor-associated macrophages was enhanced following chemotherapy. • Tumor cell debris-induced heme oxygenase-1 expression in macrophages regulates their polarization. • The proportion of M2-like macrophages was higher in macrophages treated with tumor cell debris. • The therapeutic efficacy of PTX was increased in heme oxygenase-1 KO mice compared to WT mice., Chemotherapy is commonly used as a major therapeutic option for breast cancer treatment, but its efficacy is often diminished by disruption of patient’s anti-tumor immunity. Chemotherapy-generated tumor cell debris could hijack accumulated tumor-associated macrophages (TAMs), provoking tumor recurrence. Therefore, reprogramming TAMs to acquire an immunocompetent phenotype is a promising strategy to potentiate therapeutic efficacy. In this study, we analyzed the proportion of immune cells in the breast cancer patients who received chemotherapy. To validate our findings in vivo, we used a syngeneic murine breast cancer (4T1) model. Chemotherapy generates an immunosuppressive tumor microenvironment in breast cancer. Here, we show that phagocytic engulfment of tumor cell debris by TAMs reduces chemotherapeutic efficacy in a 4T1 breast cancer model. Specifically, the engulfment of tumor cell debris by macrophages reduced M1-like polarization through heme oxygenase-1 (HO-1) upregulation. Conversely, genetic or pharmacologic inhibition of HO-1 in TAMs restored the M1-like polarization. Our results demonstrate that tumor cell debris-induced HO-1 expression in macrophages regulates their polarization. Inhibition of HO-1 overexpression in TAMs may provoke a robust anti-tumor immune response, thereby potentiating the efficacy of chemotherapy.

Early atherosclerosis depends upon responses by immune cells resident in the intimal aortic wall. Specifically, the healthy intima is thought to be populated by vascular dendritic cells (DCs) that, during hypercholesterolemia, initiate atherosclerosis by being the first to accumulate cholesterol. Whether these cells remain key players in later stages of disease is unknown. Using murine lineage-tracing models and gene expression profiling, we reveal that myeloid cells present in the intima of the aortic arch are not DCs but instead specialized aortic intima resident macrophages (MacAIR) that depend upon colony-stimulating factor 1 and are sustained by local proliferation. Although MacAIR comprise the earliest foam cells in plaques, their proliferation during plaque progression is limited. After months of hypercholesterolemia, their presence in plaques is overtaken by recruited monocytes, which induce MacAIR-defining genes. These data redefine the lineage of intimal phagocytes and suggest that proliferation is insufficient to sustain generations of macrophages during plaque progression. Williams and colleagues investigate the origin, dynamics and transcriptional profiles of aortic intima macrophages during atherosclerosis disease progression.

Light-emitting diodes (LEDs) based on metal halide perovskite nanocrystals (MHP NCs) have been rapidly developed to reach external quantum efficiencies of up to 22% with their defect-tolerant nature and extremely high color purity (full width half maxima

Background Povidone-iodine (PVP-I) is well known as an antiseptic and exhibits extensive activity against various pathogens. However, due to its uniquely unpleasant nature, it cannot be used locally to deactivate various sinonasal pathogens. Therefore, we developed a PVP-I composite that blocks the unpleasant odor of PVP-I for use as a local antiseptic in the sinonasal cavity and evaluated its effect on bacterial biofilm's formation and elimination in in vivo and in vitro models. Methods MTT, lactate dehydrogenase, and live/dead staining assay were performed to examine the cellular toxicity of PVP-I composites on the primary human nasal epithelial and RPMI 2650 cells. Crystal violet assay was performed to quantify bacterial biofilm after treating with various agents, including PVP-I and antibiotics. Hematoxylin-and-eosin staining, live/dead staining assay, and scanning electron microscopy were conducted to evaluate the effect of PVP-I on biofilm formation in a mice biofilm model. Results It was observed that the PVP-I composite did not have any significant toxic effect on the nasal epithelial cells. Furthermore, the PVP-I composite effectively inhibited the formation of bacterial biomass within a dose-dependent manner after 48 hours of incubation with Pseudomonas aeruginosa and Staphylococcus aureus. In mice, it effectively eliminated biofilm from the mucosa of the nasal cavity and maxillary sinus at the tested concentrations. Conclusion The results of this study indicate that the PVP-I composite is a promising compound that could be used locally to prevent the formation of biofilms and to eliminate them from the sinonasal cavity.

This study analyzed the risk level of non-managed products excluded from the Product Safety Certification System (PSCS) in South Korea and suggested the need of those products to be managed by PSCS. It focused on seven products including lawn trimmer, sickle, saw (saw blade), luggage carrier, snow chain, exercising ball, and alpine stick, which were found hazardous by the 1st Multi-ministries Product Safety Policy Council in 2017. The risk and need of safety management for each product were analyzed using domestic and foreign standards, accident case analysis, and Delphi technique. We then modified the analysis results based on the opinions of stakeholders such as external experts, consumers and manufacturers and suggested which products should be included in PSCS. The results showed that an exercising ball and an alpine stick should be included in PSCS to manage the potential risks. Concerning an appropriate level of safety management for those products, an exercising ball should be managed by safety verification system while an alpine stick by supplier guarantee system. Besides, further study is needed for a luggage carrier regarding its need of safety management and testing items from a long-term perspective.

This study presents a novel approach to automatically perform instant phenotypic assessment of red blood cell (RBC) storage lesion in phase images obtained by digital holographic microscopy. The proposed model combines a generative adversarial network (GAN) with marker-controlled watershed segmentation scheme. The GAN model performed RBC segmentations and classifications to develop ageing markers, and the watershed segmentation was used to completely separate overlapping RBCs. Our approach achieved good segmentation and classification accuracy with a Dice's coefficient of 0.94 at a high throughput rate of about 152 cells per second. These results were compared with other deep neural network architectures. Moreover, our image-based deep learning models recognized the morphological changes that occur in RBCs during storage. Our deep learning-based classification results were in good agreement with previous findings on the changes in RBC markers (dominant shapes) affected by storage duration. We believe that our image-based deep learning models can be useful for automated assessment of RBC quality, storage lesions for safe transfusions, and diagnosis of RBC-related diseases.

Exposure to a toxic stress environment leads to excessive inflammatory reactions and induces allergic asthma resulting in airway hyper-responsiveness. We investigated whether Rosa laevigata Michx. (RL) exhibits anti-inflammatory effects related allergic asthma in both an in vitro and in vivo studies. To investigate the preventive effect of RL, A549 cells were pretreated with non-toxic doses of RL (500, 1000 μg/mL) and induced by epidermal growth factor (EGF) (10 ng/mL). First, we evaluated cytotoxicity via a MTT assay. The inhibitory effects of NF-κB activity and COX-2 expression were confirmed by a western blot assay. In the in vivo study, BALB/c mice were challenged with regard to ovalbumin via an intraperitoneal injection of RL (50, 100 mg/kg) and were killed to collect bronchoalveolar lavage fluid, lung tissues and blood serum. The number of inflammatory cells, the secretion of IgE and related cytokines were monitored by ELISA and multiplex assays. RL significantly suppressed NF-κB activity and COX-2 expression levels in EGF-induced A549 cells. In a chronic inflammation mice model, pretreatment of RL attenuated allergic airway inflammation by reducing inflammatory cells, the secretion of IgE and related cytokines in a dose-dependent manner. The results of this study present the possibility of RL as a therapeutic agent for allergic asthma patients via the suppression of IgE and related cytokines.

Au/TiO2/GaN junctions with a TiO2 interlayer were deposited at various oxygen pressures from 5 mTorr to 80 mTorr, and their surface, microstructural, and electrical properties were investigated. Compared with a single 5 μm-Si-doped GaN film on an (0001) Al2O3 substrate, the 0.2 μm-Si-doped GaN film with an undoped GaN buffer layer demonstrated improved properties for the application to metal/semiconductor junctions. Atomic force microscope and tunneling electron microscope measurements suggested that the TiO2 interlayer deposited at room temperature exhibited a distinctive change above the oxygen deposition pressure of 40 mTorr. In contrast to the small rectification ratio of 101-102 for Au/GaN junctions, the Au/TiO2/GaN junctions with the TiO2 interlayers displayed a large rectification ratio of 106-107 when the oxygen pressure during the deposition of TiO2 interlayer was maintained at 40 mTorr. These results suggest that the leakage current and the rectification behavior in a metal/oxide/semiconductor junction can be effectively controlled using the oxygen deposition pressure for an oxide interlayer.

BRIS has been established by the Ministry of Agriculture, Food and Rural Affairs since 2011 under Article 21 of the Act on the Preservation, Management and Utilization of Agricultural Life Resources. It is an information service that provides information related to agricultural life resources in connection with the Rural Development Administration, the Forest Service, and Korea Seed & Variety Service, Agricultural Resources and Agricultural and Livestock Quarantine Headquarters. The purpose of this study is to evaluate how the users assess the information system quality (information quality, system quality) for the current Bio Resource Information Service (BRIS). Ultimately, the structural equation modeling analyzes the causal relationship between each variable and how it responds to the user's continuous use intention. As a result, information quality among information system quality and information quality among system quality used as the main variables for the evaluation of BRIS were statistically positively influenced by users' perceived usefulness, while system quality It has been analyzed to have a positive effect on the sustained use intention. The user's continuous use intention is positively influenced by the information system quality and perceived usefulness at a statistically significant level. Especially, the perceived usefulness plays a role in mediating the user's continuous use intention.

Afatinib, a second-generation, irreversible pan-HER inhibitor, shows better suppression of T790M-positive lung cancer cells than gefitinib in preclinical studies. However, whether the effect of afatinib on T790M acquisition differs from that of gefitinib when used clinically as first-line therapy remains unclear. To reaffirm the preclinical efficacy of afatinib on T790M-positive lung cancer cells, H1975 cells and established PC-9 cells resistant to gefitinib and erlotinib by T790M were used. In total, 398 patients with second biopsy at progression with stage IIIB/IV non–small cell lung cancer with EGFR mutation, treated with afatinib or gefitinib as first-line therapy, were retrospectively reviewed. Propensity score matching was used to balance covariates. Afatinib inhibited the growth of lung cancer cells with low T790M allele frequencies, which are resistant to gefitinib, but not those with high T790M allele frequencies. Afatinib and gefitinib showed similar efficacy in terms of progression-free survival (PFS) (11.5 vs 13.4 months, P = .08) and overall survival (OS) (29.3 vs 28.5 months, P = .76). T790M patients had better PFS and OS than those without T790M. There was no significant difference in the cumulative T790M acquisition ratio over time between afatinib and gefitinib (48.8% vs 59.3%, P = .317). The median time to acquire T790M was 12.9 months for afatinib and 15.7 months for gefitinib (P = .342). Although afatinib inhibited the growth of lung cancer cells with low T790M allele frequencies in preclinical studies, this could not be translated into clinical efficacy in terms of lowering the rate or delaying the time of T790M acquisition.

Titanium alloy is a highly specific strength material, having excellent mechanical characteristics such as high stiffness, fracture resistance, and hardness at high temperature, so it is applied to various fields such as automotive, aerospace and bio-industry. Yet, the excellent characteristics of titanium alloy generate high cutting heat in cutting process, stimulating tool wear and degrading process accuracy. This study looked into turning characteristics of Ti–6Al–4V alloy using super light, coated carbide and cermet tool and applied Taguchi method to identify factors affecting turning process. In the process of titanium alloy, the major cause of tool wear was adhesion of the chip by cutting heat at a high temperature, and to enhance tool life, cutting speed control is necessary. Factors affecting tool life were in the order of tool material, cutting speed and feed rate.

AlGaN/GaN heterostructures were successfully grown with the AlIn(Ga)N back barrier at 900 °C. However, the atomic composition of the AlIn(Ga)N layer was strongly dependent on the growth pressure, which resulted in a different lattice constant of the layer. The AlIn(Ga)N back barrier grown at 400 torr was almost lattice-matched to GaN layer. The AlGaN/GaN heterostructures with 10 and 15 nm-thick AlIn(Ga)N back barrier exhibited improved 2-DEG properties, compared to those of the conventional AlGaN/GaN heterostructure without the back barrier. The high electron mobility transistors (HEMTs) fabricated on the AlGaN/GaN heterostructure with a 15 nm-thick AlIn(Ga)N back barrier exhibited a very low off-state leakage current of ∼2 × 10−7 A/mm which is about 1 order lower in magnitude than the value of the device without the back barrier. The AlIn(Ga)N back barrier is a promising candidate as an alternative to conventional AlGaN and InGaN back barrier.

Purpose Transition is an important goal for ensuring that adolescents and young adults (AYAs) with spina bifida (SB) lead autonomous lives. This study aimed to identify the educational needs of AYAs with SB based on the discrepancies between perceived importance and proficiency levels during the transition process. Design and methods A cross-sectional study was conducted through face-to-face and online surveys from Jan-Dec 2020 of AYAs aged 13–25 years who had previously been diagnosed with SB. The survey consisted of 37 transition-related questions, of which 11 pertained to healthcare environments and 26 pertained to transition education needs SPSS and Excel were used for statistical analysis. Transition educational needs were analyzed by the Borich Needs Assessment Model. Higher the mean weighted discrepancy scores, lower the proficiency as compared to the perceived importance, indicating that the educational needs were high. Results Overall, 108 responses were analyzed, and 56 (51.9%) AYAs were diagnosed with lipomyelomeningocele. The highest ranked educational needs were for “Health insurance system”, “SB related urinary system diseases management”, “SB related nervous system symptoms”, and “Self-catheterization management”. “The demands for ‘SB related work life”, “Urinary incontinence management”, and “Constipation management” were significantly higher in young adults than adolescents. Conclusions During the transition process, activities perceived as important by AYAs with SB may differ from the activities that they can actually perform proficiently. It is important to assess their needs based on these discrepancies. Practice implications Transition education programs are needed that consider the individual educational needs and developmental stage-specific characteristics of AYAs with SB.

Acute pneumonia is an inflammatory disease caused by several pathogens, with symptoms such as fever and chest pain, to which children are particularly vulnerable. Gancaonin N is a prenylated isoflavone of Glycyrrhiza uralensis that has been used in the treatment of various diseases in oriental medicine. There are little data on the anti-inflammatory efficacy of Gancaonin N, and its effects and mechanisms on acute pneumonia are unknown. Therefore, this study was conducted as a preliminary analysis of the anti-inflammatory effect of Gancaonin N in lipopolysaccharide (LPS)-induced RAW264.7 cells, and to identify its preventive effect on the lung inflammatory response and the molecular mechanisms underlying it. In this study, Gancaonin N inhibited the production of NO and PGE2 in LPS-induced RAW264.7 cells and significantly reduced the expression of iNOS and COX-2 proteins at non-cytotoxic concentrations. In addition, in LPS-induced A549 cells, Gancaonin N significantly reduced the expression of COX-2 and pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6. Moreover, Gancaonin N reduced MAPK signaling pathway phosphorylation and NF-κB nuclear translocation. Therefore, Gancaonin N relieved the inflammatory response by inactivating the MAPK and NF-κB signaling pathways, thus, it is a potential natural anti-inflammatory agent that can be used in the treatment of acute pneumonia.

Background Exposure to airborne urban particulate matter (UPM) has been closely related to the development and aggravation of respiratory disease, including sinonasal disorders. Objective The aims of this study were to investigate the effect of UPM on nasal epithelial tight junctions (TJs) and mucosal barrier function and delineate the underlying mechanism by using both in vitro and in vivo models. Methods In this study, human nasal epithelial cells (hNECs) and BALB/c mice were exposed to UPMs. UPM 1648a and 1649 b were employed. TJ and endoplasmic reticulum (ER) stress marker expression was measured using western blot analysis and immunofluorescence. TJ integrity and nasal epithelial barrier function were evaluated by transepithelial electric resistance (TER) and paracellular flux. In addition, the effects of N‐acetyl‐L‐cysteine (NAC) on UPM-induced nasal epithelial cells were investigated. Results UPM significantly impaired the nasal epithelial barrier, as demonstrated by decreased protein expression of TJ and ER stress markers in human nasal epithelial cells. This finding was in parallel to reduced transepithelial electrical resistance and increased fluorescein isothiocyanate–dextran permeability. Pretreatment with NAC decreased the degree of UPM-mediated ER stress and restored nasal epithelial barrier disruption in human nasal epithelial cells (hNEC) and the nasal mucosa of experimental animals. Conclusion These data suggest that UPMs may induce nasal epithelial barrier dysfunction by targeting TJs and ER stress could be related in this process. Based on these results, we suggest that suppression of this process with an inhibitor targeting ER stress responses could represent a novel promising therapeutic target in UPM-induced sinonasal disease.

Electroluminescence efficiencies of metal halide perovskite nanocrystals (PNCs) are limited by a lack of material strategies that can both suppress the formation of defects and enhance the charge carrier confinement. Here we report a one-dopant alloying strategy that generates smaller, monodisperse colloidal particles (confining electrons and holes, and boosting radiative recombination) with fewer surface defects (reducing non-radiative recombination). Doping of guanidinium into formamidinium lead bromide PNCs yields limited bulk solubility while creating an entropy-stabilized phase in the PNCs and leading to smaller PNCs with more carrier confinement. The extra guanidinium segregates to the surface and stabilizes the undercoordinated sites. Furthermore, a surface-stabilizing 1,3,5-tris(bromomethyl)-2,4,6-triethylbenzene was applied as a bromide vacancy healing agent. The result is highly efficient PNC-based light-emitting diodes that have current efficiency of 108 cd A−1 (external quantum efficiency of 23.4%), which rises to 205 cd A−1 (external quantum efficiency of 45.5%) with a hemispherical lens. Guanidinium doping is shown to enhance the operation of perovskite nanocrystal light-emitting diodes.

The current COVID-19 pandemic has resulted in many changes in the IT systems and services of institutions, which also heightened the concerns regarding the potential increase in intrusion incidents, especially when most works in institutions are performed at home. The need for pre-training against intrusion incidents has then become extremely necessary. Unfortunately, current learning methods in existing studies are insufficient for application in the present demand because these methods were originally designed for environments that are tailored-fit for learners and not in actual environments. This paper proposes a training system, namely, computer emergency response team (CERT), that can be specifically designed for learners in an institution to provide intrusion-incident cases using a Web-based training system. CERT can easily replicate the service or system in an institution to a honeypot environment to automatically collect and classify intrusion incidents using diverse evaluation criteria so that learning can be achieved from different perspectives. Hence, the institution operating service and system can easily be replicated. Artifacts of intrusion incidents are collected using the Docker container technology and event-recordable container, which are analyzed using a Web browser without installing a separate program. Thus, optimal learning results from the analysis of actual attacks are expected.

In this work, threshold voltage modulation realized by adjusting fin width and dielectric layer were investigated through MIS-FinFETs. As fin width decreases from 120 to 30 nm, threshold voltage shifts toward positive direction and finally becomes positive value while maintaining SS smaller than 60 mV/dec. The phenomenon of achieving sub-60 mV/dec characteristics were illustrated by simulation and the concept of effective channel length. As for dielectric layer, by 20 nm-thick SiO 2 dielectric layer, device with fin width of 90 nm exhibits a threshold voltage of −0.5 V with SS as small as 50 mV/dec. Even when fin width is 30 nm, drain leakage is still not small enough when VG = 0, which indicates that the gate is not able to totally deplete the fin structure. In order to further increase threshold voltage and enhance the gate controllability, by 10 nm-thick Al 2 O 3 dielectric layer, a threshold voltage of 2 V is achieved when fin width is 40 nm with SS as small as 52 mV/dec due to the higher dielectric constant and thinner thickness of Al 2 O 3 compared with SiO 2 . Therefore, by the modulation of fin width, dielectric layer type, and dielectric thickness, threshold voltage can be carefully designed according to the application requirements while maintaining SS below 60 mV/dec.

Background We determined the characteristics and evaluated associated risks of sprayed pesticide exposure among workers cultivating Korean cabbage. The test pesticide, a mixture of 3% chlorantraniliprole and 4% indoxacarb wettable granules diluted 2000 times, was sprayed on Korean cabbage within a 3000 m2 area in Goesan, Korea. Dermal exposures were measured using a whole-body dosimetry method. Results Exposure to chlorantraniliprole was observed among ten individuals, ranging from 140.4 to 4234.0 µg person-1 . The legs were the most prominent exposure area (86.35%), with the face being the least exposed (0.06%). Exposure risk was assessed by calculating the margin of safety (MOS) on the exposure amount for each body part. The MOS based on dermal and inhalation exposure doses ranged from 59 to 1765. Conclusion Exposure was the greatest for the legs, probably as a result of the low height of the crop and the use of a long-wand sprayer. An MOS value >1 indicates a low risk for applicators using this method of application. However, with tall crops, exposure level and MOS values can vary widely, as MOS increases or decreases based on exposure dose. Therefore, future research is needed to better understand appropriate safety precautions when working with potent pesticides. © 2018 Society of Chemical Industry.

We report herein a simple ligand-assisted reprecipitation method at room temperature to synthesize mixed-cation hybrid organic–inorganic perovskite nanocrystals with low structural dimensionality., We report herein a simple ligand-assisted reprecipitation method at room temperature to synthesize mixed-cation hybrid organic–inorganic perovskite nanocrystals with low structural dimensionality. The emission wavelength of iodide-based perovskites is thus tuned from the near-infrared to the red part of the visible spectrum. While this is mostly achieved in the literature by addition of bromide, we demonstrate here a controllable blueshift of the band gap by varying the chain length of the alkylammonium ligands. Furthermore, an antisolvent washing step was found to be crucial to purify the samples and obtain single-peak photoluminescence with a narrow linewidth. The so-formed nanocrystals exhibit high and stable photoluminescence quantum yields exceeding 90% over 500 hours, making these materials ideal for light-emitting applications.

Conventional organic light-emitting devices without an encapsulation layer are susceptible to degradation when exposed to air, so realization of air-stable intrinsically-stretchable display is a great challenge because the protection of the devices against penetration of moisture and oxygen is even more difficult under stretching. An air-stable intrinsically-stretchable display that is composed of an intrinsically-stretchable electroluminescent device (SELD) integrated with a stretchable color-conversion layer (SCCL) that contains perovskite nanocrystals (PeNCs) is proposed. PeNCs normally decay when exposed to air, but they become resistant to this decay when dispersed in a stretchable elastomer matrix; this change is a result of a compatibility between capping ligands and the elastomer matrix. Counterintuitively, the moisture can efficiently passivate surface defects of PeNCs, to yield significant increases in both photoluminescence intensity and lifetime. A display that can be stretched up to 180% is demonstrated; it is composed of an air-stable SCCL that down-converts the SELD's blue emission and reemits it as green. The work elucidates the basis of moisture-assisted surface passivation of PeNCs and provides a promising strategy to improve the quantum efficiency of PeNCs with the aid of moisture, which allows PeNCs to be applied for air-stable stretchable displays.

Although Campylobacter is the main cause for bacterial acute gastroenteritis (AGE), there has been no notable clinical research into it, especially for Korean children. In this study, we share our experience of clinical, laboratory and image findings with Campylobacter AGE. Methods Between May 2013 and June 2016, children diagnosed as having Campylobacter AGE were retrospectively enrolled in our study. Campylobacter AGE was considered diagnosed when a patient had symptoms of bacterial AGE and a positive Campylobacter result in stool using multiplex PCR. Results Among 539 patients with suspected bacterial AGE, 31 (5.8%) patients had a positive result for Campylobacter. The average age of the 31 patients was 10.2 ± 5.0 years with a range between 1.1 and 16.9 years. Eighteen (58%) of the total patients were hospitalized between June and August. Diarrhea (93.5%), abdominal pain (83%) and fever (83%) were common symptoms. For 20 patients (65%), diarrhea lasted for less than three days, and fever lasted for 2.1 days on average. Among the 20 patients subjected to imaging studies, 12 patients (60%) showed bowel wall thickening on the right side of colon. In blood tests of 30 patients, 22 (73%) and 29 (97%) patients exhibited leukocytosis and elevated C-reactive protein, respectively. During treatment for Campylobacter AGE, prediagnostic empirical antibiotics were used for 6 (19%) patients. All patients recovered without complications. Conclusions Among the children with suspected bacterial AGE, 5.8% had a positive result on Campylobacter in stool using multiplex PCR. Therefore, we observe that Campylobacter AGE should be considered in school-age children who have diarrhea, fever, and abdominal pain.

Background/Aims: Outcomes of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancer (EGC) need to be further evaluated. We aimed to simulate the outcomes of ESD for undifferentiated-type EGC from a surgical database. Methods: Among 802 patients who underwent gastrectomy with endoscopic biopsy for poorly differentiated adenocarcinoma (PD-type) or signet ring cell carcinoma (SRC-type), ESD candidates meeting the expanded indication (n=280) were selected by reviewing the endoscopic images. According to the surgical pathologic results, the outcomes of the ESD simulation were evaluated. Results: Among the candidates, 104 (37.1%) were PD-type and 176 (62.9%) were SRC-type. The curative resection (CR) rate was 42.1%. Among the patients with CR, three patients (2.5%) showed lymph node metastasis (LNM). Three EGCs with CR and LNM were mucosal cancers ≥1.0 cm in size. The CR rate was higher in the SRC-type than in the PD-type (48.3% vs 31.7%, respectively, p=0.007). In the SRC-type, the CR rate was increased, with a smaller size criterion for the ESD indication, but was similar between the 1.0 cm and 0.6 cm criteria (63.3% and 63.6%, respectively), whereas the CR rate was below 50% in all of the different tumor size criteria (2.0 to 0.6 cm) in the PD-type. Conclusions: In undifferentiated- type EGC, ESD should be considered in selected patients with tumor sizes

Objective: The purpose of this study was to investigate the impact of wearing various types of shoes on gait ability in stroke survivors and in order to gain information in regards to shoes that could possibly replace ankle orthosis. Design: Cross-sectional study. Methods: Eight hemiplegic survivors diagnosed with stroke participated in the study. Gait was analyzed using the GAITRite Electronic Walkway (CIR System Inc., USA) when subjects walked with no showed, walked with non-ankle-covered shoes, and walked with ankle-covered shoes. This study collected gait variables, including velocity, cadence, step length, stride length, single support time, and double support time, respectively. Results: In the comparison of walking with no shoes, non-ankle-covered shoes, and ankle-covered shoes, there were significant differences in gait velocity, step length, stride length, and the less affected side single support time (p

Post-stroke depression (PSD) affects approximately one-third of stroke patients. PSD not only impairs recovery and lowers quality of life, but has also serious neurological consequences, high mortality, and stroke recurrence risks. Studies on PSD-related prognostic factors are still lacking, especially environmental factors. Moreover, relieving factors after PSD in stroke patients has not been reported. This study aimed to investigate (study design 1) risk factors for PSD diagnosis after three months, and (study design 2) related factors for the relieving of early PSD after three months. This retrospective study included 227 patients hospitalized for acute ischemic stroke within three days at Jeonbuk National University Hospital from January to December 2019. The depressive status was assessed using the Hamilton Depression Rating Scale (HDRS) at admission and after three months. Clinical and laboratory data were analyzed for relevant prognostic factors. (Study design 1) HDRS score at admission (adjusted odds ratio (aOR) 1.22, 95% confidence interval (CI) 1.14–1.31, p &lt, 0.001) and hospitalization period (aOR 1.11, 95% CI 1.02–1.20, p = 0.013) were confirmed as prognostic factors of PSD after three months. (Study design 2) The National Institute of Health Stroke Scale (NIHSS) score at discharge (aOR 0.80, 95% CI 0.68–0.94, p = 0.006) and HDRS score at admission (aOR 0.80, 95% CI 0.71–0.89, 0.001) were confirmed as prognostic factors of depression improvement after three months. In conclusion, environmental factors such as hospitalization period could be important in managing PSD. Factors related to PSD improvement are expected to be helpful in establishing a strategy for PSD recovery.

In this paper, we investigated characteristics of AlGaN/GaN high-electron mobility transistors (HEMTs) with high resistive buffer structure consisted of periodically carbon-doped (PCD) GaN buffer layer and AlGaN back barrier layer. The PCD structure was proposed for reducing undesirable trapping effects, which resulted in effective suppression of the current collapse compared to that in conventional carbon buffer structure. To further improve the dynamic performances of the device and to increase the electron confinement of the 2-D electron gas (2-DEG) channel, AlGaN back barrier was inserted between the GaN channel and the PCD buffer layer, which results in greatly improved current collapse with slightly improved 2-DEG mobility compared to those of the device without back barrier. The OFF-state leakage current of the device with back-barrier is about 2 orders lower in magnitude than that of device without back barrier, which leads to the breakdown voltage of 2 kV and figure of merit of 2.27 GV $^{2} \Omega ^{-1}$ cm−2 for the device with LGD of $10~{{\mu }}\text{m}$ , one of the highest values ever reported for the GaN-based HEMTs.

Atopic dermatitis (AD), a common childhood skin disorder, can limit a child's learning and physical activities. South Korean mothers, as primary caregivers, experience anxiety and helplessness when caring for their ill children. The aim of this study was to develop a hybrid AD education programme (consisting of a face-to-face session followed by 8 online sessions) and evaluate its effects on anxiety, caregiving efficacy and caregiving behaviour among mothers of children with AD. Twenty mothers of patients with AD treated in a South Korean hospital received one on-site session and 8 weekly online modules. After the intervention, mothers' mean±standard deviation anxiety reduced (from 50.3 ± 14.2 to 31.7 ± 6.3 points, t = 5.75, p < 0.001). Their caregiving efficacy and caregiving behaviour improved significantly, from 18.3 ± 3.5 to 29.4 ± 3.2 points (t = -9.64, p < 0.001) and from 47.7 ± 7.7 to 78.8 ± 4.9 points (t = -14.4, p < 0.001), respectively. The effects of the hybrid education programme for this population were significant. Healthcare providers should consider examining the programme nationwide, including in rural areas, while investigating its long-term effects.

Background/aims In some Western countries, up to 50% of patients with ankylosing spondylitis (AS) have subclinical gut inflammation. This study was conducted to evaluate the prevalence and severity of gut inflammation and to determine clinical factors associated with colonic inflammation in Korean AS patients who performed ileocolonoscopy without evidence of established inf lammatory bowel diseases before. Methods One hundred and eight AS patients who underwent ileocolonoscopy were included in this study. Patients were divided into two groups based on gross ileocolonoscopic findings; patients with inflammatory lesions, and patients without inflammatory lesions. Results Inf lammatory lesions in ileocolonoscopic findings were found in 40 patients. The Ankylosing Spondylitis Disease Activity Score C-reactive protein was higher in the group with inflammatory lesions and gut lesions were found often in the terminal ileum. The risk of inflammatory lesions was higher for AS patients whose symptoms required ileocolonoscopy than for AS patients who underwent routine ileocolonoscopy screening (odds ratio, 3.96). However, abnormal lesions were detected also in 17.6% of the patients who underwent ileocolonoscopy for routine screening and most of them were erosion and ulcer. Among patients with inflammatory lesions (n = 40), 23 showed subclinical gut inflammation associated with AS and 17 were diagnosed finally as Crohn's disease (n = 12), intestinal tuberculosis (n = 4), and ulcerative colitis (n = 1). Conclusions Our findings suggest that ileocolonoscopy might be recommended regularly in AS patients even without gastrointestinal symptoms, especially in the patients with high AS activity.