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Background Polypropylene (PP) is used in various products such as disposable containers, spoons, and automobile parts. The disposable masks used for COVID-19 prevention mainly comprise PP, and the disposal of such masks is concerning because of the potential environmental pollution. Recent reports have suggested that weathered PP microparticles can be inhaled, however, the inhalation toxicology of PP microparticles is poorly understood. Results Inflammatory cell numbers, reactive oxygen species (ROS) production, and the levels of inflammatory cytokines and chemokines in PP-instilled mice (2.5 or 5 mg/kg) increased significantly compared to with those in the control. Histopathological analysis of the lung tissue of PP-stimulated mice revealed lung injuries, including the infiltration of inflammatory cells into the perivascular/parenchymal space, alveolar epithelial hyperplasia, and foamy macrophage aggregates. The in vitro study indicated that PP stimulation causes mitochondrial dysfunction including mitochondrial depolarization and decreased adenosine triphosphate (ATP) levels. PP stimulation led to cytotoxicity, ROS production, increase of inflammatory cytokines, and cell deaths in A549 cells. The results showed that PP stimulation increased the p-p38 and p-NF-κB protein levels both in vivo and in vitro, while p-ERK and p-JNK remained unchanged. Interestingly, the cytotoxicity that was induced by PP exposure was regulated by p38 and ROS inhibition in A549 cells. Conclusions These results suggest that PP stimulation may contribute to inflammation pathogenesis via the p38 phosphorylation-mediated NF-κB pathway as a result of mitochondrial damage.

89Zr is an emerging radionuclide with promising application in nuclear medicine for the non-invasive diagnosis of various cancers with PET imaging. This paper would discuss optimization efforts in the production of 89Zr carried out at Accelerator Radioisotope Development Team, Korea Atomic Energy Research Institute. Optimized conditions reveal high production yields of 89Zr ~ 37 ± 1.4 MBq/µA using 89Y(p,n)89Zr, ~ 12.7 MeV of proton, and 35 µA using yttrium coin target with indigenously constructed 30 MeV Cyclotron (RFT-30). Besides, the production optimization, quality control, and biological behavior of [89Zr]Zr-oxalate, chloride and, DFO demonstrated promising results.

Background: To determine the optimal direction of the syndesmotic screw and introduce a consistent landmark for practical application by analyzing three-dimensional (3D) modeling and virtual implantation.Methods: A total of 102 cadaveric lower legs (50 males and 55 females, average height of 160.6 ± 7.1cm) were used to reconstruct a 3D model by using the Mimics® software and the joint morphology was evaluated. Syndesmotic cylinders (Ø3.5 mm/Length 100 mm) were transversely placed in the proximal end of the incisura fibularis for simulating screw fixation. The tibial proximal cylinder, which was tangent to the posterior tibial condyles, was traced and the angle between the two cylinders was measured as the tibial torsion angle (TTA). After rotating the syndesmotic cylinder parallel to the ground, the overlapping degree between the proximal fibula and tibia were assessed as a radiologic indicator. Results: Concerning tibial torsion, the TTA was an average of 36.7° (range, 17.2°–54.4°, SD 8.78) When the syndesmotic cylinder was rotated to be parallel to the ground, the proximal fibula had non- or linear overlap with the lateral border of the tibia, regardless of the joint morphology. In this nonoverlapping view, compared to the mortise view, the three criteria for normal fibular length could be better visualized. Conclusion: The syndesmotic cylinder in the proximal end of the incisura fibularis could be consistently placed parallel to the ground by internally rotating the tibia until there was a non- or linear overlap between the proximal fibula and the tibia, regardless of the joint morphology.

This study aimed to prepare a bio-based organic adsorbent (W-PEI) with amine functionalization via Schiff’s reaction without carbonization of biomass. The bio-based organic adsorbent was prepared from wheat bran husk (WH), and amine functionalized to absorb CO2 gas by conjugating polyethyleneimine (PEI) via Schiff’s reaction to the aldehyde groups of periodated WH (p-WH). Then, the bio-based organic adsorbent was compounded with low-density polyethylene (LDPE) using a twin screw extruder. The polymeric composites (LDPE/W-PEI) and W-PEI were studied to characterize chemical structure, thermal properties, and CO2 adsorption ability. The CO2 adsorption capacity was measured by thermogravimetric analysis (TGA), and the analysis was performed through the exchange of N2 and CO2 under isothermal conditions at 75 °C. The amount of CO2 adsorption was 0.425 mmol/g of W-PEI powder, while that of polymeric composite (LDPE/W-PEI_20%) containing 20 wt% W-PEI was 0.034 mmol/g, which corresponds to an adsorption efficiency of 40% compared to that of the powder state. Therefore, polymeric composites with improved CO2 gas adsorption could be successfully applied to food packaging and building materials.

As a matrix resin of silica/epoxy hybrid encapsulation material with high heat resistance and low coefficient of thermal expansion, a tri-functional triglycidyl p-aminophenol (TGPAP) epoxy was successfully synthesized with the desired chemical structure by reacting epichlorohydrin with p-aminophenol using sodium hydroxide catalyst. In order to produce highly pure TGPAP with lower viscosity, a physical thin film vacuum distillation was carried out after synthesis, resulting in 97% purity with the viscosity of 700 cps at room temperature. Silica/TGPAP hybrid was fabricated using two kinds of ground fumed silica with different sizes of 20 μm and 9 μm. Glass transition temperature of the hybrid was found to be as high as 185 °C. Viscosity of the hybrid was 30,000 cps at room temperature before curing, implying good processability. When two different sizes of silica were used with 1 to 1 weight ratio, very low coefficient of thermal expansion of 22.79 ppm/°C was obtained. From thermal shock test, no cracks were observed even after 1,000 cycles of thermal shock between −40 °C and 125 °C when 67 wt% (45.8 vol%) of silica was involved in the hybrid. In conclusion, silica/TGPAP hybrid with improved processability, superior thermal shock resistance and low thermal expansion coefficient could be fabricated as electronic device encapsulation.

Low spatter CO2 arc welding is often used for ultra-thin steel sheets with a thickness of under 1.0-mm. In this paper, a high speed forward and reverse motion control algorithm for the motor in a welding torch and a dedicated controller for it are presented. The dedicated controller is designed with a motor driver IC (A3930) and a DSP (TMS320F-28069) coded with the proposed motion control algorithm. It is easy to optimize the operating parameters in the proposed algorithm according to various thin steel sheets. Since the torch motor must be able to feed or retract welding wire at a high speed while cooperating with the brushed DC motor in the wire feeder, the performance required in selecting the torch motor is examined and presented in this paper. With the proposed control algorithm, an optimal torch motor and the developed controller, the feeding and retracting motions of the welding wire at high speeds are possible. This results in low heat inputs to the base material and low spatter short-circuiting transfer. To verify the superiority of CO2 arc welding with the proposed torch motor control algorithm and the developed controller, an arc welding robot prototype system was fabricated and 100% purity CO2 gas arc welding with thin steel plates with a thickness of 0.8-mm was performed. This was accomplished with an interlocking a 50 W class brushless DC motor as the torch motor, the developed low spatter motion controller and an arc welding power supply.

A bipolar low-voltage DC (LVDC) distribution system used in residential and building applications requires AC–DC converters and voltage balancers that balance the two DC bus polarities. The bipolar DC bus voltage level only relies on the voltage balancer tied with the AC grid. An isolated DC–DC converter for an energy storage system (ESS) with the voltage balancing capability is proposed to prevent the bipolar voltage level collapse caused by the failure of the grid-tied voltage balancer. The proposed converter topology is an enhanced three-port dual-active-bridge (DAB) converter which can balance the bipolar DC voltage level without complex control. Furthermore, it has less current stress in power switches than that of the conventional three-port DAB converter. The effectiveness of the proposed converter is verified with a 3-kW prototype converter.

This study tested the efficacy of the phosphodiesterase type III inhibitor cilostazol in Alzheimer’s disease patients with white matter lesions treated with donepezil in comparison with donepezil monotherapy using fluorodeoxyglucose ((18)F) positron-emission tomography (FDG PET). A 24-week, randomized, double-blind, placebo-controlled, parallel-group study was conducted. Thirty-six Alzheimer’s disease patients with white matter lesions who received donepezil (n = 18 each in the cilostazol and placebo groups) were enrolled. Participants underwent pre and post FDG PET imaging scans and three rounds of clinical and neuropsychological tests. The cilostazol group did not show a significant decrease of regional glucose metabolism; however, regional glucose metabolism was significantly decreased in the parietal and frontal lobes of the placebo group. The repeated measures ANOVA measuring differences in uptake change revealed that regional glucose metabolism in the left inferior frontal gyrus was significantly more preserved in the cilostazol group than that in the placebo group (p

The recycling of raw-state bottom ash as it is holds an advantage from an economic and environmental standpoint in that it omits pre-processes such as milling and wetting. Its physical and chemical properties are first characterized for the purpose, and then the use of raw-state bottom ash for aggregates in construction materials is proposed. Preplaced aggregate concrete or dry-mixing concrete scheme can be selectively applied according to the particle size requirement of bottom ash aggregate. Preplaced bottom ash aggregate concrete is produced by placing the bottom ash aggregate in formwork and injecting grout to fill the voids. To ensure the injectability of the grout, relatively large-sized particles, greater than 5 mm, are recommended to be used. In the case of dry-mixing concrete, this is originally designed for manufacturing concrete masonry units and concrete blocks with a low water-to-cement ratio and consolidated zero-slump concrete using a mechanized vibrating mold. The experimental results show that bottom ash aggregate concrete has moderate compressive strength with a low density.

Scoring atopic dermatitis (AD) severity with the Eczema Area and Severity Index (EASI) in an objective and reproducible manner is challenging. Automated measurement of erythema, papulation, excoriation, and lichenification severity using images has not yet been investigated. Our aim was to determine whether convolutional neural networks (CNNs) could assess erythema, papulation, excoriation, and lichenification severity at a level of competence comparable to dermatologists. We created a standard dataset of 8,000 clinical images showing AD. Each component of the EASI was scored from 0 to 3 by three dermatologists. We trained four CNNs (ResNet V1, ResNet V2, GoogLeNet, and VGG-Net) with the image dataset and determined which CNN was the most suitable for erythema, papulation, excoriation, and lichenification scoring. The brightness of the images in each dataset was adjusted to − 80% to + 80% of the original brightness (i.e., 9 levels by 20%) to investigate if the CNNs accurately measured scores if image brightness levels were changed. Compared to the dermatologists’ scoring, accuracy rates of the CNNs were 99.17% for erythema, 93.17% for papulation, 96.00% for excoriation, and 97.17% for lichenification. CNNs trained with brightness-adjusted images achieved a high accuracy without the need to standardize camera settings. These results suggested that CNNs perform at level of competence comparable to dermatologists for scoring erythema, papulation, excoriation, and lichenification severity.

Patients with chronic kidney disease (CKD) have a high prevalence of left ventricular hypertrophy (LVH), which increases as kidney function decreases. LVH pathophysiology is complex, making it difficult to generalise its evolution in CKD. Therefore, early detection and prevention of risk factors are critical. Assessment and management of volume status can minimise cardiovascular complications including LVH. We retrospectively investigated the associations between fluid overload and LVH in patients with stage 5 CKD not undergoing dialysis in prospective cohort of 205 patients (age: 59.34 ± 13.51 years; women: 43.4%). All patients, free of intrinsic heart disease, were assessed for relative overhydration/extracellular water (OH/ECW) by bioimpedance spectroscopy. Our results show that markers reflecting fluid balance were significantly higher in the LVH group and as OH/ECW increased, the left ventricular mass index (LVMI) trended higher. Furthermore, our results show that systolic blood pressure, serum phosphorus levels, and OH/ECW were independently associated with LVMI and that OH/ECW was independently associated with LVH. Structural and functional evaluation of the heart using echocardiography and volume status assessment using bioimpedance should be performed simultaneously in patients with early-stage CKD, even in those without evident cardiovascular disease.

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

Crosslinked organosilicon-acrylate copolymer thin film with desired chemical composition was successfully fabricated by a simply modified initiated chemical vapor deposition (iCVD) process. Unlike the conventional iCVD copolymerization process, in our novel process, comonomers were injected together as one gas phase into the polymerization chamber from miscible liquid comonomer mixture. 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (V4D4) and cyclohexyl methacrylate (CHMA) were used as the comonomers and tert-butyl peroxide was used as the initiator. From Fourier transform infrared (FTIR) spectra and solvent resistance test, we clearly confirmed that the crosslinked copolymer thin film with desired chemical composition could be obtained by controlling only the mixing ratio of liquid comonomers. It is expected that crosslinkable V4D4 organosilicon moiety provides hydrophobic moisture barrier property and CHMA acrylate moiety provides mechanical flexibility and better adhesion. We observed a certain level of moisture blocking capability of the copolymer thin film, implying potential application of the crosslinked organosilicon-acrylate copolymer thin film as flexible polymer buffer layer in organic/inorganic or metal oxide hybrid moisture barrier for flexible display or electronic devices.

Prognostics and health management (PHM) has emerged as an intelligent solution to improve the availability of manufacturing systems. PHM consists of system health monitoring, feature extraction, fault diagnosis, and fault prognosis through remaining useful life estimation. However, the application of PHM to manufacturing systems is challenging because systems have become more complex and uncertain. In particular, small and medium-sized enterprises have difficulty in applying PHM due to the lack of internal expertise, time and resources for research and development. The objective of this paper is to develop a framework to provide a readily usable and accessible guideline for PHM application to manufacturing systems. A survey was performed to gather the current practices in dealing with system failures and maintenance strategies in the field. A framework was developed for giving a guideline for PHM application based on common core modules across manufacturing systems and their kinds with respect to the amount of available data and domain knowledge. A reference table was developed to track the PHM techniques for feature extraction, fault diagnosis, and fault prognosis. Finally, fault prognosis of a system was conducted as a case study, following the framework and the reference table to verify its practical use.

Fluorodeoxyglucose (FDG) positron emission tomography (PET) is useful to predict Alzheimer’s disease (AD) conversion in patients with mild cognitive impairment (MCI). However, few studies have examined the extent to which FDG PET alone can predict AD conversion and compared the efficacy between visual and computer-assisted analysis directly. The current study aimed to evaluate the value of FDG PET in predicting the conversion to AD in patients with MCI and to compare the predictive values of visual reading and computer-assisted analysis. A total of 54 patients with MCI were evaluated with FDG PET and followed-up for 2 years with final diagnostic evaluation. FDG PET images were evaluated by (1) traditional visual rating, (2) composite score of visual rating of the brain cortices, and (3) composite score of computer-assisted analysis. Receiver operating characteristics (ROC) curves were compared to analyze predictive values. Nineteen patients (35.2%) converted to AD from MCI. The area under the curve (AUC) of the ROC curve of the traditional visual rating, composite score of visual rating, and computer-assisted analysis were 0.67, 0.76, and 0.79, respectively. ROC curves of the composite scores of the visual rating and computer-assisted analysis were comparable (Z = 0.463, p = 0.643). Visual rating and computer-assisted analysis of FDG PET scans were analogously accurate in predicting AD conversion in patients with MCI. Therefore, FDG PET may be a useful tool for screening AD conversion in patients with MCI, when using composite score, regardless of the method of interpretation.

Accumulation of triphenylphosphonium (TPP) is normally observed in the mitochondria from the extracellular spaces due to the high difference in plasma membrane potential of the mitochondria. In the cancer cells, the mitochondrial membrane potential gap is higher as compared to that of normal cells resulting in elevated uptake of TPP. Silica nanoparticles (SNPs) being widely developed and used for biomedical applications, in this study, we tried to modify the surface of SNPs with varying amounts of TPP to verify their possible application as a positron emission tomography (PET) agent. The studies confirmed that the high level of TPP loading on the surface of SNPs possess higher positive charge (+ 31.5 mV). Owing to this behavior of plasma membrane potential of cancerous cells the uptake of positively charged SNPs was much higher in tumor cells than that of normal cells which was confirmed by PET imaging.

We used a water-in-oil emulsification method to prepare particulate CO2 absorbents from branched poly(ethyleneimine) (PEI), utilizing 13C nuclear magnetic resonance spectroscopy to determine the amount of free PEI NH2 groups and thus calculate the required cross-linker amount. The functional groups and reactivity of branched PEI particles were characterized by Fourier transform infrared spectroscopy, and their CO2 absorption capacity was determined by thermogravimetric analysis. Dynamic light scattering measurements showed that the synthesized particles exhibited sizes of 0.2-2 μm and high surface areas, which resulted in high CO2 absorption capacities of up to 2.18 mmol CO2 per gram sorbent at 75 °C.

A study was conducted to determine the appropriate surface treatment for rice husks (RH) in polymer composite film to improve the physical properties relative to those of untreated RH/linear low-density polyethylene (LLDPE) film. Pulverized RH was treated with NaOH (RH-m) and acetic acid (RH-ac) to prepare composite films with LLDPE resin. The treated RH showed typical mercerization and acetylation, as confirmed by spectroscopic and thermal analysis methods. The RH-m sample was mercerized, allowing decomposition of hemicellulose and partially amorphous cellulose. The RH-ac sample was processed via acetylation inducing partial lignin decomposition. Field-emission scanning electron microscopy showed smaller gaps at the RH/LLDPE interface for RH-m and RH-ac compared to that with untreated RH, implying increased composite compatibility. RH-m in particular showed superior tensile strength (15.85 N/mm2), elongation (884%), Young’s modulus (60.01 N/mm2), and tear strength (7.71N/mm2) compared to untreated RH and RH-ac.

Metallically conducting flexible alginate fibers with superior mechanical strength and environmental stability was obtained by metal ion-exchange using a simply modified continuous wet-spinning process. Spinning solution was prepared by dissolving Na-alginate polymer in distilled water, followed by spinning into CaCl2 coagulation bath to form Ca-alginate swollen gel fiber. The Ca-alginate fiber was then immersed into AgNO3 aqueous solution for incorporation of Ag+ ion into the swollen Ca-alginate alginate fiber, resulting in the alginate fiber complexed with both Ca++ and Ag+ ions (Ag/Ca-alginate fiber). The Ag/Ca-alginate fiber was finally immersed into aqueous dimethylamine borane complex (DMAB) reduction solution, reducing Ag+ ions to Ag nanoparticles (AgNP) in the fiber. The AgNP embedded Ca-alginate conducting fiber (AgNP/Ca-alginate fiber) was washed with distilled water several times and dried. It was observed that AgNPs were uniformly formed and dispersed both on the surface and inside of the AgNP/Ca-alginate fiber. The fiber exhibits superior room temperature electrical conductivity and mechanical strength as high as 2,000 S/cm and 290 MPa, respectively. The AgNP/ Ca-alginate fiber also possessed excellent environmental stability, showing little conductivity change even after 800 hours under a harsh 60 oC and 70% relative humidity condition. Conductive fabric with extremely low surface resistivity of 0.6 Ω/□ could be fabricated using the AgNP/Ca-alginate fibers.

Small mobile robots with transformable wheels have recently emerged thanks to their increased mobility and maneuverability. When a high payload is applied to these robots, however, wheel transformation becomes difficult because they must directly overcome the payload’s weight. In this paper, we propose a wheel that can be transformed from its starting circular shape (radius, 56 mm) to a wheel with three legs (radius, 99 mm) under a high payload with low operating force. The key design principle of this wheel is to kinematically decoupled legs and passive locking. Its legs are kinematically decoupled but operated by a single air pump using a pneumatic channel connected to soft pneumatic actuators installed at each leg. Application of pressure causes the legs to behave like a coupled system through the pneumatic channel. With pressurization, the two legs that are not in contact with the ground easily emerge from body, and the leg in contact with the ground emerges once the wheel rotates. Once emerged, each leg is supported by a rigid pawl instead of by the soft pneumatic actuators. This setup enables the legs to be transformed independently with low air pressure, even under high payloads. It reduces system weight and the energy required to maintain the transformed shape. This legged wheel can overcome obstacles up to 2.9 times the radius of the wheel in its circular form, and wheel transformation can be accomplished with 85 kPa air pressure for payloads up to 1115 g.

Poly(vinyl alcohol) (PVA)/ linear low-density polyethylene (LLDPE) composite films were prepared using PVAs of various molecular weights and degrees of hydrolysis. The crystallinity, water permeability, mechanical properties, and optical properties of the composite films were analyzed based on the absorption properties of the different PVAs. The formation of the composite film became increasingly difficult with increase in the molecular weight and the degree of hydrolysis of PVA, because the resulting crystallinity increased the intramolecular hydrogen bonding of the hydroxyl groups on the main chains of PVA. The 4-98/LLDPE composite film absorbed water gradually and continuously for a long time, and its water vapor absorption rate was similar to that of the 4-88/LLDPE film but lower than that of the PVA 205/LLDPE film. The mechanical properties of the 4-98/LLDPE film were slightly better than those of the 4-88/LLDPE film but inferior to those of the PVA 205/LLDPE film.

In biological applications of nanoparticles, the control of physicochemical properties such as size, shape, and surface charge enables the improvement of their ability for cancer target. In addition, it can be tracked by labeling in these nanoparticles with medical radionuclides for detection of cancer. Here, we report novel chelator-free direct-labeling of hierarchical hematite nanoclusters with 89Zr (89Zr-IONCs) through hydrothermal reaction to develop biocompatible radiolabeled nanoparticle which is effective for tracking cancer cells. Characterization of 89Zr-IONCs revealed that the zirconium ions were tightly bound inside hematite crystals with intervals of glutamic acid absorbed on their surfaces having spindle shape with a mean width of 180 nm and length of 80 nm. This method showed promising radiolabeling yield and labeling stability in biological environments which was ≥ 99%. Their high colloidal stability in serum was considerably maintained for the span of a week by the formation of protein corona with the hematite nanoclusters. For the result of biological evaluations, cytotoxicity assay provides evidence of the high biocompatibility of the product. The elevated in vitro cellular uptake of 89Zr-IONCs for the CT-26 and A549 cells was observed. Furthermore, we found that the spindle shape of 89Zr-IONCs was more effective for cell internalization compared with round shape due to the extended interfacial surface area with a cell membrane when their endocytosis is started. Our one-pot synthesized 89Zr-incorporated hematite nanoclusters show the promising approach for a simple and highly stable chelator-free radiolabeling system, which exploits the non-toxic potential carrier to target cancer cells.

Biomimetic nanoparticles (NPs) have been actively studied for their biological compatibility due to its distinguished abilities viz. long-term circulation, low toxicity, ease for surface modification, and its ability to avoid phagocytosis of NPs by macrophages. Coating the NPs with a variety of cell membranes bearing the immune control proteins increases drug efficacy while complementing the intrinsic advantages of the NPs. In this study, efforts were made to introduce oxophilic radiometal 89Zr with hollow mesoporous silica nanospheres (HMSNs) having abundant silanol groups and were bioengineered with red blood cell membrane (Rm) having cluster of differentiation 47 (CD47) protein to evaluate its long-term in vivo behavior. We were successful in demonstrating the increased in vivo stability of synthesized Rm-camouflaged, 89Zr-labelled HMSNs with the markedly reduced 89Zr release. Rm camouflaged 89Zr-HMSNs effectively accumulated in the tumor by avoiding phagocytosis of macrophages. In addition, re-injecting the Rm isolated using the blood of the same animal helped to overcome the immune barrier. This novel strategy can be applied extensively to identify the long-term in vivo behavior of nano-drugs while enhancing their biocompatibility.

Probiotics such as lactobacilli and bifidobacteria have healthpromoting effects by immune modulation. In the present study, we examined the immunomodulatory properties of Lactobacillus curvatus WiKim38, which was newly isolated from baechu (Chinese cabbage) kimchi. The ability of L. curvatus WiKim38 to induce cytokine production in bone marrow-derived dendritic cells (BMDCs) was determined by enzyme-linked immunosorbent assay. To evaluate the molecular mechanisms underlying L. curvatus Wikim38-mediated IL-10 production, Western blot analyses and inhibitor assays were performed. Moreover, the in vivo anti-inflammatory effects of L. curvatus WiKim38 were examined in a dextran sodium sulfate (DSS)-induced colitis mouse model. L. curvatus WiKim38 induced significantly higher levels of IL-10 in BMDCs compared with that induced by LPS. NF-κB and ERK were activated by L. curvatus WiKim38, and an inhibitor assay revealed that these pathways were required for L. curvatus WiKim38-induced production of IL-10 in BMDCs. An in vivo experiment showed that oral administration of L. curvatus WiKim38 increased the survival rate of mice with DSS-induced colitis and improved clinical signs and histopathological severity in colon tissues. Taken together, these results indicate that L. curvatus Wikim38 may have health-promoting effects via immune modulation, and may thus be applicable for therapy of various inflammatory diseases.

Spherical porous polymer particles with high surface area were synthesized using the water-in-oil-inwater (W/O/W) emulsion polymerization and Friedel-Crafts reaction. After the preparation of W/O emulsions, spherical porous polymer particles were synthesized by suspension polymerization. Spherical porous polymer precursor particles were subjected to Friedel-Crafts reaction using a Lewis acid catalyst. The properties of the final products synthesized with different porogen contents in the water-in-oil (W/O) emulsion were explored. The Friedel-Crafts reaction was used to increase the Brunauer-Emmett-Teller (BET) surface area. In order to identify the effects of the porogen levels and of the Friedel-Crafts reaction, the synthesized porous particles were analyzed by particle size analyzer (PSA), Hg porosimetry, and the BET surface area method. In addition, the morphology of the particles was investigated by FE-SEM.

Near-elderly adults go through many changes in socioeconomic status, such as retirement, which may affect their mental health differently according to when they live. We aimed to compare the prevalence of major depressive disorder (MDD) and its changes according to sociodemographic factors using nationally representative surveys of Korean near-elderly adults conducted 10 years apart. Nationwide community samples of individuals aged 55–64 years living in 2001 (n = 1256) and 2011 (n = 1066) were compared. Face-to-face interviews were conducted using the Korean version of the Composite International Diagnostic Interview to diagnose MDD. Sociodemographic data were collected using self-reported questionnaires including questions on employment and economic status. We examined differences in MDD prevalence and its association with sociodemographic factors over time by calculating 2011-to-2001 odds ratios (ORs) using multivariable logistic regression models. Among near-elderly people, MDD tended to be more prevalent in 2011 than in 2001. However, only near-elderly men in 2011 showed a higher risk of MDD compared with those in 2001 (2011-to-2001 OR 4.19), while women did not. The prevalence ratio by gender decreased from 7.04 in 2001 to 2.34 in 2011. Among vulnerable sociodemographic groups, a significant increase in MDD was observed in unemployed men (adjusted OR 8.35), but not in unemployed women or other vulnerable groups. This study provides evidence of a substantial increase in MDD in Korean near-elderly men and suggests that unemployment should be considered as an important correlate of MDD in this group.

We designed a 68Ga labeled Fe3O4 nano-biocomposite for dual applications as diagnostic imaging agent in positron emission tomography (PET)/magnetic resonance imaging (MRI). The nano-biocomposites (68GaNHFCNP) were fabricated via surface modified iron oxide nanoparticles and NOTA as bi-functional chelating agent with 68Ga isotopes from 68Ge/68Ga generator. The structure and morphological properties of nano-biocomposite was characterized by XRD, TEM and IR analysis. 68GaNHFCNPs exhibits very low cytotoxicity and high cellular uptake upon SK-BR-3 and CT-26 cell lines. The advantages of high biocompatibility, magnetism and cell uptake make this composite promising as a potential probe of PET/MRI for effective detection of cancer.

It is very important to understand flow patterns within the continuous casting mold because they have a significant impact on product quality. Water model experiment and particle image velocimetry were conducted to identify the fluid flow pattern in the steel slab continuous casting mold. The fluid flow pattern in the mold is not steady but instead an oscillatory flow with a specific oscillation frequencies. Many studies have been reported about oscillatory flow within the mold. However, these studies do not provide a clear explanation of physical origin of oscillatory flow. We identified the physical origins of various specific oscillation frequencies, and confirmed through experimentation and simulation that each frequency is related to the cross flow and injection stream oscillation. Moreover, the degree of oscillation at each frequency appears differently depending on the location within the mold, and is shown to have a effect near the mold wall. These results provide a better understanding of complex oscillatory flow patterns within the mold.

We synthesized core-shell microcapsule absorbents with crosslinked poly(acrylic acid) (PAA) as the core and poly(styrene-alt-maleic anhydride) (cPAA-PSMA) as the shell by the precipitation polymerization method for delayed absorption of excess water in cement mortar. To control the shell thickness, cPAA-PSMA capsules were synthesized with the core-to-shell monomer mass ratios of 1: 0 (cPAA #1), 1: 0.5 (cPAA-PSMA #2), 1: 1 (cPAA-PSMA #3), and 1: 1.5 (cPAA-PSMA #4). The viscosity of the cement paste with cPAA-PSMA #4 absorbent increased slowly until 90minutes after absorbent addition, beyond which it increased rapidly. This suggests that mortars with cPAA-PSMA #4 absorbents can secure up to 90 minutes of working time. Incorporation of 1.0 wt% cPAA-PSMA #4 into cement mortar increased the compressive and flexural strengths by approximately 35% and 22%, respectively, compared to those of cement mortars without absorbents.

This study compared the factors associated with the utilization of mental health services across various age cohorts, with a particular focus on the differential influence of the stigma placed on mental illness on the use of these services. The present study used data from a Korean national epidemiological survey of mental disorders among community-dwelling adults aged 18–74 years (n = 3,055). The subjects were categorized into three age groups: young (18–39), middle-aged (40–59), and late adulthood (60–74). The Perceived Devaluation-Discrimination scale was used to assess the stigma placed on mental disorders in each group. The influence of perceived stigma on lifetime utilization of mental health services was examined according to age cohort using multiple logistic regression analyses that were adjusted for various sociodemographic factors (p

The first synthesis of a well-defined star polymer consisting of three regioregular poly(3-hexylthiophene) (rr-P3HT) arms emanating from an electron acceptor thiacalix[3]wtriazine core via direct arylation polymerization is described. Its structural characteristics as well as optical and thermal properties were evaluated using Fourier transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR), X-ray diffraction (XRD), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and atomic force microscopy (AFM) methods. The UV-vis and photoluminescence spectroscopy results evidenced the impact of the electron-withdrawing feature of the thiacalix[3]triazine core and the star structure on the optical behavior of the star-shaped material, as compared to the rr-P3HT linear analogue. The anion-binding property of the star-shaped P3HT resulting in fluorescence quenching was also studied.

Zinc (Zn) is an essential trace element that plays important roles in the immune system. There is little known about the role of trace elements in allergic diseases, and previous reports have shown conflicting results. The aim of this study was to investigate the relationship between serum Zn levels and total or allergen-specific immunoglobulin E (IgE) levels. The initial candidates for this study were those who participated in the 5th Korean National Health and Nutrition Examination Survey 2010 (n = 8,958), and 1,867 adults who had serum total and allergen specific-IgE levels measured were included. Upon adjusting for covariates, mean total IgE, Dermatophagoides farinae and dog-specific IgE levels increased significantly as the Zn levels decrease from the highest to the lowest quartile (p = 0.009, 0.004, and D. farinae-, cockroach-, and dog-specific IgE levels (p-value for linear trend = 0.004, 0.006, 0.027, and

Internet gaming disorder (IGD) has been conceptualized as a behavioral addiction and shares clinical, neuropsychological, and personality characteristics with alcohol use disorder (AUD), but IGD dose not entail brain exposure to toxic agents, which renders it different from AUD. To achieve a clear understanding of the neurobiological features of IGD, we aimed to identify morphological and functional changes in IGD and compare them with those in AUD. Individuals with IGD showed larger volume in the hippocampus/amygdala and precuneus than healthy controls (HCs). The volume in the hippocampus positively correlated with the symptom severity of IGD. Moreover, functional connectivity analysis with the hippocampus/amygdala cluster revealed that the left ventromedial prefrontal cortex showed stronger functional connectivity in individuals with IGD compared to those with AUD. In contrast, individuals with AUD exhibited the smaller cerebellar volume and thinner medial frontal cortex than HCs. The volume in the cerebellum correlated with impaired working memory function as well as duration of illness in AUD group. Findings suggested that altered volume and functional connectivity in the hippocampus/amygdala in IGD might be associated with abnormally enhanced memory process of gaming-related cues, while abnormal cortical changes and cognitive impairments in AUD might be associated with neurotoxic effects of alcohol.

Background Personality traits are not only associated with psychiatric symptoms, but also with treatment seeking behavior. Our purpose was to examine the relationship between mental health service utilization and personality characteristics in a nationwide community sample of Korean adults. Method Of the 6022 subjects aged 18–74 years who participated in the Korean Epidemiologic Catchment Area study, 1544 (25.6%) with a lifetime diagnosis of any DSM-IV psychiatric disorder were analyzed. Diagnostic assessments were based on the Composite International Diagnostic Interview and personality constructs were measured by Big Five Personality Inventory-10. Results Of the 1544 participants, 275 (17.8%) had used mental health services. Multivariate analyses revealed positive associations between mental health service utilization and both neuroticism and openness, and an inverse association between mental health service utilization and agreeableness. Conclusions These findings suggest that specific personality traits may have a role in treatment-seeking behaviors for mental health problems independent of the psychiatric disorder.

One of the theories regarding oral carcinogenesis is that the tumor growth is initiated from cancer stem cells (CSCs) that self-renew and give rise to differentiated tumor cells, like stem cells do in normal tissues. The most common methods of CSC identification are based on CSC marker expression in carcinogenesis. This study examined the expression of CD133 and CD44, the most commonly used CSC biomarkers in oral squamous cell sarcoma (SCC), with the goal of identifying molecular biomarkers whose expression is associated with the multistep oral carcinogenesis. The expression of CD133, CD44, proliferating cell nuclear antigen (PCNA), and Cytokeratin (CK) was examined by Western blot analysis and confirmed by immunohistochemistry in a 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis model. Also, the expression of aldehyde dehydrogenase 1 (ALDH1), OCT-4 and Nanog were investigated for alteration of cancer cell stemness by Western blot. Along with the progress of multistep carcinogenesis, there were slight increases of CD133 and CD44 expression in the dysplasia group compared with normal rats. However, CD133 protein level was significantly overexpressed in SCC. The expression of PCNA and CK were low in normal group, but sequentially increased in SCC. ALDH1, Nanog and OCT-4 expression were significantly increased according to SCC grade during carcinogenesis. The findings indicate that CD133 is useful in identifying oral CSCs, which suggests that CD133 may serve as a predictor to identify CSCs with a high risk of oral cancer development.

A meso- and microporous hypercrosslinked polyxylene was synthesized via Friedel-craft reaction in the presences of iron(III) chloride as a Lewis acid catalyst. Dichloro-p-xylene, which has both benzene ring and chlorine functional groups, was used as monomer for the one-step synthetic process. A different amount of catalyst was used for polymerization and hypercrosslinking reaction. Yield and properties of the hypercrosslinked polyxylene were affected by the concentration of catalyst. Maximum yield of hypercrosslinked polyxylene was 65.4% above 30 wt%/monomer. Maximum Brunauer-Emmett-Teller (BET) surface area was 1168.37 m2/g at 40 wt%/monomer. Micropore volume and peak diameter at maximum differential volume, determined using Horvath-Kawazoe (H-K) method, were 0.2324 cm3/g and 0.55 nm, respectively. Open image in new window

In order to realize flexible organic light emitting diode (OLED), it is critically important to protect moisture and oxygen penetration into the flexible device through the polymer substrates because of intrinsically poor stability of organic materials of OLED to moisture. Since complete protection of the moisture penetration is almost impossible, moisture absorbents are used inside OLED. In this study, metal oxide/polymer hybrid nanofiber with mechanical flexibility and efficient moisture absorption capability was fabricated by electrospinning. Hydrophilic poly(vinyl pyrrolidone) (PVP) or hydrophobic poly(vinylidenefluoride) (PVDF) and calcium oxide (CaO) were used as the fiber forming polymers and as the moisture absorbing particle, respectively. Polymers were first dissolved in appropriate solvents and CaO was then dispersed in the prepared polymer solutions. The hybrid solution was then electrospun, producing the hybrid nanofiber web looking like paper with thickness of about 100 µm. It was observed that all CaO particles were uniformly held by the nanofiber. It was also observed that only a small portion of the surface of CaO particles was covered by fiber since the fiber diameter was much smaller than the CaO particle size. This implied effective moisture absorption through the free surface of CaO. The hybrid nanofiber absorbed moisture very efficiently upto about 70 % of the nanofiber mass. Once moisture was absorbed by the nanofiber, it was never released even at 150 °C in vacuum for 2 hours. It is, therefore, expected that the nanofiber may be applied as the flexible thin moisture absorbent to improve stability of the flexible OLED.