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Microalgae are unicellular photosynthetic microorganisms typically found in aquatic environments and they play a vital role in the global carbon and energy cycles. Discrimination of dead and live cells is an important factor in microalgae research and environmental monitoring. Numerous research on the effects of various microalgae has been conducted concerning cell viability. Recently, dyes such as Trypan Blue (TB), Evans Blue (EB), and Neutral Red (NR) have been employed to assess the viability of microalgae. Existing approaches for identifying dead and living microalgal cells all have flaws, such as the requirement for staining and pre-treatment. A machine learning method was created to distinguish the living and dead microalgal cells by using of a digital holography microscopy, and the accuracy of this technique was greater. The machine learning method offers a new way of studying both freshwater and marine microalgal cell cultures. This review focuses on the existing methods and emerging technology for determining dead and living microalgae cells. This review work will enlighten the new research for the detection of live or dead microalgae. [ABSTRACT FROM AUTHOR]

The growing demand for electric vehicles highlights the need for energy storage solutions with higher densities, spotlighting Li metal anodes as potential successors to traditional Li-ion batteries (LIBs). Achieving longer calendar aging life for Li metal anodes is crucial for their practical use, given their propensity for corrosion due to a low redox potential, which leads to compromised cycling stability and significant capacity loss during storage. Recent research investigated that this susceptibility is mainly dependent on the surface area of Li metal anode and the properties of the solid electrolyte interphase (SEI), particularly its stability and growth rate. Our research adds to this understanding by demonstrating that the amount of Li plating is a key factor in its corrosion during open-circuit storage, as assessed across various electrolytes. We discovered that increasing the Li plating amount effectively reduces Coulombic efficiency (C.E.) loss during aging, due to a lower surface area-to-Li ratio. This implies that the choice of electrolyte for optimal storage life should consider the amount of Li plating, with higher capacities promoting better storage characteristics. [ABSTRACT FROM AUTHOR]

Political behavior is observed in every organization and is one of the most significant phenomena in organizations. Despite its importance, few studies have been conducted to explore the impact of perceived organizational politics on public organizations. This study examined the direct impact of perceived organizational politics on organizational performance as well as its indirect impact on performance through its influence on two mediating factors, task conflict and relationship conflict, using a data from a survey of New Jersey local government employees. Findings are discussed along with practical considerations and suggestions for future research. [ABSTRACT FROM AUTHOR]

A for-cause biopsy is performed to diagnose the cause of allograft dysfunction in kidney transplantation. We occasionally encounter ambiguous biopsy results in symptomatic kidney transplant recipients. Yet, the allograft survival outcome in symptomatic recipients with nonspecific allograft biopsy findings remains unclear. The purpose of this study was to analyze the impact of nonspecific for-cause biopsy findings in symptomatic kidney transplant recipients. We retrospectively collected records from 773 kidney transplant recipients between January 2008 and October 2021. The characteristics of transplant recipients with nonspecific findings in the first for-cause biopsy were analyzed. Nonspecific allograft biopsy findings were defined as other biopsy findings excluding rejection, borderline rejection, calcineurin inhibitor toxicity, infection, glomerulonephritis, and diabetic nephropathy. The graft outcome was compared between recipients who had never undergone a for-cause biopsy and those who had a first for-cause biopsy with nonspecific findings. The graft survival in recipients with nonspecific for-cause biopsy findings was comparable to that in recipients who did not require the for-cause biopsy before and after propensity score matching. Even in symptomatic kidney transplant recipients, nonspecific allograft biopsy findings might not be a poor prognostic factor for allograft survival compared to recipients who did not require the for-cause biopsy. [ABSTRACT FROM AUTHOR]

Background: Chest x-ray is commonly used for pulmonary abnormality screening. However, since the image characteristics of x-rays highly depend on the machine specifications, an artificial intelligence (AI) model developed for specific equipment usually fails when clinically applied to various machines. To overcome this problem, we propose an image manipulation pipeline. Methods: A total of 15,010 chest x-rays from systems with different generators/detectors were retrospectively collected from five institutions from May 2020 to February 2021. We developed an AI model to classify pulmonary abnormalities using x-rays from a single system. Then, we externally tested its performance on chest x-rays from various machine specifications. We compared the area under the receiver operating characteristics curve (AUC) of AI models developed using conventional image processing pipelines (histogram equalization [HE], contrast-limited histogram equalization [CLAHE], and unsharp masking [UM] with common data augmentations) with that of the proposed manipulation pipeline (XM-pipeline). Results: The XM-pipeline model showed the highest performance for all the datasets of different machine specifications, such as chest x-rays acquired from a computed radiography system (n = 356, AUC 0.944 for XM-pipeline versus 0.917 for HE, 0.705 for CLAHE, 0.544 for UM, p ≤ 0.001, for all) and from a mobile x-ray generator (n = 204, AUC 0.949 for XM-pipeline versus 0.933 for HE, p = 0.042, 0.932 for CLAHE (p = 0.009), 0.925 for UM (p = 0.001). Conclusions: Applying the XM-pipeline to AI training increased the diagnostic performance of the AI model on the chest x-rays of different machine configurations. Relevance statement: The proposed training pipeline would successfully promote a wide application of the AI model for abnormality screening when chest x-rays are acquired using various x-ray machines. Key points: • AI models developed using x-rays of a specific machine suffer from generalization. • We proposed a new image processing pipeline to address the generalization problem. • AI models were tested using multicenter external x-ray datasets of various machines. • AI with our pipeline achieved the highest diagnostic performance than conventional methods. [ABSTRACT FROM AUTHOR]

Ship biofouling is one of the main vectors for the introduction and global spread of non-indigenous organisms. Diatoms were the early colonizers of ship hulls; however, their community composition on ships is poorly understood. Herein, we investigated the diatom community on the hull samples collected from two Korean research vessels Isabu (IRV) and Onnuri (ORV) on September 2 and November 10, 2021, respectively. IRV showed low cell density (345 cells/cm2) compared to ORV (778 cells/cm2). We morphologically identified more than 15 species of diatoms from the two research vessels (RVs). The microalgae in both RVs were identified as Amphora, Cymbella, Caloneis, Halamphora, Navicula, Nitzschia, and Plagiogramma. Of them, the genus Halamphora was found to be predominant. However, both RVs had a varied dominant species with a significant difference in body size; Halamphora oceanica dominated at IRV, and Halamphora sp. at ORV, respectively. Molecular cloning showed similar results to morphological analysis, in which Halamphora species dominated in both RVs. The hull-attached species were distinct from species found in the water column. These results revealed diatoms communities that are associated with ship hull-fouling at an early stage of biofilm formation. Moreover, ships arriving from different regions could show some variation in species composition on their hull surfaces, with the potential for non-indigenous species introduction. [ABSTRACT FROM AUTHOR]

Post-stroke secondary brain damage is significantly influenced by the induction and accumulation of α-Synuclein (α-Syn). α-Syn-positive inclusions are often present in tauopathies and elevated tau levels and phosphorylation promotes neurodegeneration. Glycogen synthase kinase 3β (GSK-3β) is a known promoter of tau phosphorylation. We currently evaluated the interaction of α-Syn with GSK-3β and tau in post-ischemic mouse brain. Transient focal ischemia led to increased cerebral protein–protein interaction of α-Syn with both GSK-3β and tau and elevated tau phosphorylation. Treatment with a GSK-3β inhibitor prevented post-ischemic tau phosphorylation. Furthermore, α-Syn interaction was observed to be crucial for post-ischemic GSK-3β-dependent tau hyperphosphorylation as it was not seen in α-Syn knockout mice. Moreover, tau knockout mice show significantly smaller brain damage after transient focal ischemia. Overall, the present study indicates that GSK-3β catalyzes the α-Syn-dependent tau phosphorylation and preventing this interaction is crucial to limit post-ischemic secondary brain damage. [ABSTRACT FROM AUTHOR]

Vitamin C has recently been identified as an epigenetic regulator by activating ten-eleven translocases (TETs), enzymes involved in generating DNA hydroxymethylcytosine (5hmC). Currently, we investigated whether high-dose vitamin C promotes neuroprotection through epigenetic modulation of 5hmC, if there are sex-specific differences in outcome, and the therapeutic potential of vitamin C in stroke-related comorbidities in adult mice. Post-stroke treatment with ascorbate (reduced form), but not dehydroascorbate (oxidized form), increased TET3 activity and 5hmC levels and reduced infarct following focal ischemia. Hydroxymethylation DNA immunoprecipitation sequencing showed that ascorbate increased 5hmC across the genome and specifically in promoters of several stroke pathophysiology-related genes, particularly anti-inflammatory genes. Ascorbate also decreased markers of oxidative stress, mitochondrial fragmentation, and apoptosis in cortical peri-infarct neurons and promoted motor and cognitive functional recovery in both sexes via TET3. Furthermore, post-stroke ascorbate treatment reduced infarct volume and improved motor function recovery in aged, hypertensive and diabetic male and female mice. Delayed ascorbate treatment at 6 h of reperfusion was still effective at reducing infarct volume and motor impairments in adult mice. Collectively, this study shows that post-stroke treatment with high-dose ascorbate protects the brain through epigenetic reprogramming and may function as a robust therapeutic against stroke injury. [ABSTRACT FROM AUTHOR]

We construct an infinite family of topologically slice knots that are not smoothly concordant to their reverses. More precisely, if T denotes the concordance group of topologically slice knots and ρ is the involution of T induced by string reversal, then T / Fix (ρ) contains an infinitely generated free subgroup. The result remains true modulo the subgroup of T generated by knots with trivial Alexander polynomial. [ABSTRACT FROM AUTHOR]

The pattern-recognition-based control of myoelectric prostheses offers amputees a natural, intuitive approach to more finely control the prostheses. In this context, we recently developed a multichannel surface electromyography (sEMG) module with a low sampling rate and applied it for hand-motion research. In this study, we investigate the effects of the sEMG-signal sampling rate and feature extraction window length on the classification accuracy in hand-motion recognition. Ten normal subjects and one forearm amputee were made to wear an armband module consisting of eight EMG sensors, and seven and four hand movements of the normal subjects and amputee, respectively, were measured. The EMG signal was measured at 500 Hz and down-sampled to 250, 100, and 50 Hz. Four time-domain features (mean average value, waveform length, zero crossing, and slope sign change) were calculated as the sEMG features with six selected window lengths, which were increased in 50 ms intervals (50, 100, 150, 200, 250, and 300 ms). Hand-motion recognition was performed using artificial neural network, support vector machine, decision tree, and k-nearest neighbor classifiers. Our results showed that for all classifiers and all subjects, the hand-motion classification accuracy increases with an increase in the sampling rate and window length. We believe that our findings will aid in selecting the appropriate sampling rate and window length for prosthetics meant for daily use. [ABSTRACT FROM AUTHOR]

Alanine aminotransferase (ALT) levels reflect skeletal muscle volume and general performance, which are associated with chronic obstructive pulmonary disease (COPD) development and prognosis. This study aimed to investigate ALT levels as a risk factor for COPD development. This 13-year population-based retrospective observational cohort study included 422,452 participants for analysis. We classified groups according to the baseline ALT levels (groups 1–5: ALT (IU/L) < 10; 10–19; 20–29; 30–39; and ≥ 40, respectively). The incidence of COPD was the highest in group 1, decreasing as the group number increased in males, but not in females. The Cox regression analysis in males revealed that a lower ALT level, as a continuous variable, was a significant risk factor for COPD development [univariable, hazard ratio (HR): 0.992, 95% confidence interval (CI): 0.991–0.994; multivariable, HR: 0.998, 95% CI: 0.996–0.999]. In addition, COPD was more likely to develop in the lower ALT level groups (groups 1–4; < 40 IU/L), than in the highest ALT level group (group 5; ≥ 40 IU/L) (univariable, HR: 1.341, 95% CI: 1.263–1.424; multivariable, HR: 1.097, 95% CI: 1.030–1.168). Our findings suggest that males with low ALT levels should be carefully monitored for COPD development. [ABSTRACT FROM AUTHOR]

Despite advances in therapeutic strategies for multiple sclerosis (MS), the therapy options remain limited with various adverse effects. Here, the therapeutic potential of CKD-506, a novel HDAC6-selective inhibitor, against MS was evaluated in mice with myelin oligodendrocyte glycoprotein35–55 (MOG35–55)-induced experimental autoimmune encephalitis (EAE) under various treatment regimens. CKD-506 exerted prophylactic and therapeutic effects by regulating peripheral immune responses and maintaining blood–brain barrier (BBB) integrity. In MOG35–55-re-stimulated splenocytes, CKD-506 decreased proliferation and downregulated the expression of IFN-γ and IL-17A. CKD-506 downregulated the levels of pro-inflammatory cytokines in the blood of EAE mice. Additionally, CKD-506 decreased the leakage of intravenously administered Evans blue into the spinal cord; CD4+ T cells and CD4−CD11b+CD45+ macrophage/microglia in the spinal cord was also decreased. Moreover, CKD-506 exhibited therapeutic efficacy against MS, even when drug administration was discontinued from day 15 post-EAE induction. Disease exacerbation was not observed when fingolimod was changed to CKD-506 from day 15 post-EAE induction. CKD-506 alleviated depression-like behavior at the pre-symptomatic stage of EAE. In conclusion, CKD-506 exerts therapeutic effects by regulating T cell- and macrophage-mediated peripheral immune responses and strengthening BBB integrity. Our results suggest that CKD-506 is a potential therapeutic agent for MS. [ABSTRACT FROM AUTHOR]

Elevated concentration of matrix metalloproteinase-8 (MMP-8) in amniotic fluid is a known predictor of intra-amniotic inflammation and infection. The aim of this study was to determine the nature of the association between MMP-8 levels in oral fluid obtained immediately after birth and acute histologic chorioamnionitis (HCA) in preterm delivery. Oral fluid was collected from 93 consecutive preterm birth newborns between gestational weeks of 24 + 0 and 36 + 6. Concentrations of MMP-8 and interleukin-8 (IL-8) in after birth oral fluid were measured by ELISA. Acute HCA was defined as the presence of neutrophils infiltration into chorioamnionic membranes. Logistic regression analysis was used for the statistical analysis. MMP-8 concentrations in after birth oral fluid were significantly higher for women with acute HCA than for those without (median [range]; 68.3 ng/mL [0.06–12,479.6] vs. 10.2 ng/mL [0.06–1808.2], p = 0.002). A strong association was observed between MMP-8 and IL-8 levels (γ2 = 0.87, p < 0.01). The cutoff level of MMP-8 in after birth oral fluid for acute HCA was 39.7 ng/mL (sensitivity of 63.2%, specificity of 81.1%). Multivariable logistic regression analysis showed MMP-8 in after birth oral fluid had an odds ratio of 4.17 for acute HCA (95% confidence interval [CI] = 1.08–16.17, p = 0.03). An elevated MMP-8 level in after birth oral fluid is associated with acute HCA in preterm birth. Newborn oral fluid immediately after birth might provide another source for information of intra-amniotic condition just before birth. [ABSTRACT FROM AUTHOR]

Surface modification is one of the important steps for synthesizing hydrophobic silica aerogels by ambient pressure drying in which silylating agent plays a vital role. Trimethylchlorosilane and many kinds of methoxysilanes like trimethylmethoxysilane, dimethyldimethoxysilane, and methyltrimethoxysilane have been used as the silylating agents. In this work, silylation effects were investigated with different molar ratios of silylating agent/n-hexane mixture. In addition, the mechanism of the silylation reaction is explained based on the molecular structures by considering the number of methoxy/methyl groups. The silylation extent was characterized by using optical imaging, bulk density and porosity analyses, Fourier-transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller, Barrett-Joyner-Halenda, and contact angle measurements. It has been found that the methoxysilane-based silylating agents can be used as a replacement without producing the harmful hydrochloric acid and retaining the similar tendency to trimethylchlorosilane in surface modification. This research approach seeks to an alternative silylating agent by investigating the impact on the surface modification based on the molecular structural parameters and reaction mechanisms. Highlights: Sodium silicate-based silica aerogels were formed by using various silylating agents. Silylation ability depends on the molecular structure of the methoxysilane. Silylation could be evaluated from pore structure and electron distribution degree. DMDMS was found to be excellent silylating agent among the methoxysilanes studied. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop an accurate and efficient algorithm for post-fall detection. Thirty healthy male subjects were recruited and asked to perform 23 movements, comprising 14 activities of daily living and nine fall motions. The algorithm was developed using the ANN toolbox provided with MATLAB and inertial measurement unit (IMU) data were used to distinguish between fall and non-fall cases. An IMU sensor was located at the center between the left and right anterior superior iliac spines. A total of 32 feature vectors were extracted from 3-axis acceleration and angular velocity signals. Based on the five different ranking algorithms (relief-F, T-score, correlation, Fisher score, and minimum redundancy maximum relevance) used, feature vector subsets comprising the feature vectors were created and subsequently evaluated. Accuracy was compared according to the number of feature vectors constituting the subset, which were based on rank-lists. The results showed that the subset comprising all the feature vectors showed the best accuracy (99.86%), but a similar accuracy could be obtained with a subset comprising fewer feature vectors. The T-score was found to be the most optimal among the five ranking algorithms. Furthermore, T-score with two feature vectors achieved an accuracy of 99.17%. The results of this study are expected to assist in the construction of subsets of feature vectors based on ranking algorithms for post-fall detection with high accuracy and less computational cost. [ABSTRACT FROM AUTHOR]

The need to reduce the maximum injection pressure has been considered an important subject for storage efficiency and safety. Brine extraction from the storage formation is one of the most reliable methods to manage formation pressure. When brine extraction is performed, it is very important to select the optimum location of the extraction well, where the storage efficiency can be maximized. In this study, the sensitivities of the distance between injection/extraction wells and the length or depth of extraction intervals was investigated with a 20,183 metric ton/year injection/extraction rate for 30 years. The injected CO2 moves upward by buoyancy and spreads horizontally along with the top of the storage formation. Therefore, CO2 was re-extracted through extraction wells in the case with fully perforated intervals. Even if the intervals were shorter than 20 m, CO2 was re-extracted with an extraction distance within 500 m from the injection well. Excluding scenarios with CO2 re-extraction, the injection pressures at injection wells were reduced by 71.7% and the volumes of CO2 plume increased by 18.8%, compared with the maximum pressure and the gaseous volume of CO2 in case 1. It was found that the shorter extraction interval of the well located in the bottom part of the reservoir can significantly improve the injection performance, thus reducing the chance of CO2 re-extraction. With the viewpoint of long-term injectivity, in general, it was confirmed that as the distance of brine extraction increases, the injectivity decreases. However, we could find a considerable exception in general trends. If the extraction well is located within the lateral extension range of the CO2 migration, brine extraction can limit the lateral migration of CO2 and consequently increase the overpressure induced by the injection. Therefore, when determining the optimal location of the extraction well, the expected migration range of CO2 as well as the distance to the injection well, the depth and length of the extraction interval should be considered. [ABSTRACT FROM AUTHOR]

Development of efficient catalysts for selective electroreduction of CO2 to high-value products is essential for the deployment of carbon utilization technologies. Here we present a scalable method for preparing Cu electrocatalysts that favor CO2 conversion to C2+ products with faradaic efficiencies up to 72%. Grazing-incidence X-ray diffraction data confirms that anodic halogenation of electropolished Cu foils in aqueous solutions of KCl, KBr, or KI creates surfaces of CuCl, CuBr, or CuI, respectively. Scanning electron microscopy and energy dispersive X-ray spectroscopy studies show that significant changes to the morphology of Cu occur during anodic halogenation and subsequent oxide-formation and reduction, resulting in catalysts with a high density of defect sites but relatively low roughness. This work shows that efficient conversion of CO2 to C2+ products requires a Cu catalyst with a high density of defect sites that promote adsorption of carbon intermediates and C–C coupling reactions while minimizing roughness. Selective reduction of carbon dioxide to high-value products is key for advancing carbon capture and utilization technologies. Here the authors prepare a copper catalyst for electrocatalytic conversion of carbon dioxide to C2+ products with enhanced selectivity that is attributed to a high density of surface defects. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease requiring frequent outpatient visits and lifelong management. We aimed to evaluate the roles of frequent outpatient visits in prognosis of COPD. We used claims data in the national medical insurance review system provided by the Health Insurance Review and Assessment Service of Korea from May 1, 2014 to April 30, 2015. A definition of COPD was used based on the diagnosis code and medication. Frequent visitors were defined as subjects who visited the outpatient clinic for COPD three or more times per year. Among 159,025 subjects, 117,483 (73.9%) were classified as frequent visitors. Frequent visitors underwent pulmonary function tests and used various inhalers more often than did infrequent visitors. The rates of COPD exacerbation requiring admission to a general ward, emergency room, or intensive care unit were significantly lower in frequent visitors than in infrequent visitors. In multivariable analysis, frequent visits were identified as an independent factor preventing COPD exacerbation that required admission to a ward (odds ratio [OR], 0.387), emergency room, (OR, 0.558), or intensive care unit (OR, 0.39) (all P < 0.001). In conclusion, we showed frequent outpatient visits reduce the risk of COPD exacerbation by 45–60%. [ABSTRACT FROM AUTHOR]

Epoxy composites are widely used in commercial products. For industrial purposes, storage stability is one of their most important characteristics. To enable this feature, alternative promoters that are stable at a low-energy state, where they do not react, are needed. Zeolitic imidazolate frameworks (ZIFs) are organic–inorganic complexes, and they contain imidazolate linkers, which are one of the promoters in the epoxy–amine reaction. In this study, the stability of a one-pot epoxy–amine composite was improved by using ZIFs as promoters. ZIFs were synthesized using the solvothermal method, and their structure were confirmed using X-ray diffraction analysis and field-emission scanning electron microscopy. The activation energy of the ZIFs was measured using the non-isothermal method of differential scanning calorimetry, and it was calculated using the Kissinger equation. Furthermore, the storage stability of the one-pot epoxy–amine system was measured considering the viscosity change with time at constant temperature. The viscoelastic behavior of the cured sample was demonstrated using dynamic mechanical analysis. [ABSTRACT FROM AUTHOR]

Quantum dot (QD) light-emitting diodes (LEDs) are ideal for large-panel displays because of their excellent efficiency, colour purity, reliability and cost-effective fabrication1–4. Intensive efforts have produced red-, green- and blue-emitting QD-LEDs with efficiencies of 20.5 per cent4, 21.0 per cent5 and 19.8 per cent6, respectively, but it is still desirable to improve the operating stability of the devices and to replace their toxic cadmium composition with a more environmentally benign alternative. The performance of indium phosphide (InP)-based materials and devices has remained far behind those of their Cd-containing counterparts. Here we present a synthetic method of preparing a uniform InP core and a highly symmetrical core/shell QD with a quantum yield of approximately 100 per cent. In particular, we add hydrofluoric acid to etch out the oxidative InP core surface during the growth of the initial ZnSe shell and then we enable high-temperature ZnSe growth at 340 degrees Celsius. The engineered shell thickness suppresses energy transfer and Auger recombination in order to maintain high luminescence efficiency, and the initial surface ligand is replaced with a shorter one for better charge injection. The optimized InP/ZnSe/ZnS QD-LEDs showed a theoretical maximum external quantum efficiency of 21.4 per cent, a maximum brightness of 100,000 candelas per square metre and an extremely long lifetime of a million hours at 100 candelas per square metre, representing a performance comparable to that of state-of-the-art Cd-containing QD-LEDs. These as-prepared InP-based QD-LEDs could soon be usable in commercial displays. A method of engineering efficient and stable InP/ZnSe/ZnS quantum dot light-emitting diodes (QD-LEDs) has improved their performance to the level of state-of-the-art cadmium-containing QD-LEDs, removing the problem of the toxicity of cadmium in large-panel displays. [ABSTRACT FROM AUTHOR]

A robust algorithm to classify various hand postures using EMG signals is needed for the EMG-based electric hand prosthesis with the multiple degrees of freedom. In this study, an armband-type multi-channel EMG module was designed, and an algorithm for classifying seven different types of hand postures was developed using the artificial neural network (ANN). The classification accuracy was evaluated for ten normal volunteers, according to the independence of the EMG feature groups, donning and doffing training data size, and whether or not majority voting was applied. The results revealed an optimized accuracy of 97.49 ± 3.87% when majority voting was applied after using high independence feature group (HIFG) to perform classification training for seven or more sessions. The algorithm was successfully applied to provide seven different hand postures in a 5-finger myoelectric hand prosthesis. Confusion matrices and separability indexes of ANN classifiers showed that the major misclassifications, in spite of a good accuracy, were found to be lateral pinch versus palmar pinch, and index versus thumb-up. However, with the classification training for seven or more sessions, the probability of misclassification significantly decreased. [ABSTRACT FROM AUTHOR]

Cerebral ischemia is known to activate the repressor element-1 (RE1)-silencing transcription factor (REST) which silences neural genes via epigenetic remodeling and promotes neurodegeneration. We presently determined if REST inhibition derepresses target genes involved in synaptic plasticity and promotes functional outcome after experimental stroke. Following transient focal ischemia induced by middle cerebral artery occlusion (MCAO) in adult rats, REST expression was upregulated significantly from 12 h to 1 day of reperfusion compared to sham control. At 1 day of reperfusion, REST protein levels were increased and observed in the nuclei of neurons in the peri-infarct cortex. REST knockdown by intracerebral REST siRNA injection significantly reduced the post-ischemic expression of REST and increased the expression of several REST target genes, compared to control siRNA group. REST inhibition also decreased post-ischemic markers of apoptosis, reduced cortical infarct volume, and improved post-ischemic functional recovery on days 5 and 7 of reperfusion compared to the control siRNA group. REST knockdown resulted in a global increase in synaptic plasticity gene expression at 1 day of reperfusion compared to the control siRNA group and significantly increased several synaptic plasticity genes containing RE-1 sequences in their regulatory regions. These results demonstrate that direct inhibition of the epigenetic remodeler REST prevents secondary brain damage in the cortex and improves functional outcome potentially via de-repression of plasticity-related genes after stroke. [ABSTRACT FROM AUTHOR]

Trimethylethoxysilane (TMES) has been recognized as a good co-precursor to increase the degree of hydrophobicity during the synthesis of a silica aerogel because of its methyl groups. Therefore, some physical properties of silica aerogels, including the contact angle and porosity, were investigated using TMES as a co-precursor at different molar ratios with the main precursor such as tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS). In contrast to TMES, most silylating agents such as hexamethyldisilazane (HMDZ) and trimethylchlorosilane (TMCS) have been used for surface modification because of their ability to enhance the hydrophobicity of the aerogel surface. This work examines the silylation effect, which includes increasing hydrophobicity by TMES to determine the possibility of using it as an alternative silylating agent during ambient pressure drying in the synthesis of sodium silicate-based silica aerogel. In addition, the physical properties of sodium silicate-based silica aerogels with silylation under different TMES/TMCS volume ratio are investigated. The physical properties of sodium silicate-based aerogels can be changed by the TMES/TMCS volume ratio during the surface modification step. Aerogels with a high specific surface area (458 m2/g), pore volume (3.215 cm3/g), porosity (92.7%), and contact angle (131.8°) can be obtained TMES/TMCS volume ratio of 40/60. Sodium silicate-based silica aerogel was synthesized by APD using TMES/TMCS surface co-modifying agent.TMES can act as an alternative surface modification agent with TMCS.Hydrophobicity was not measured at the case of only TMES usage.TMES/TMCS surface co-modifier for silylation enhances the physical properties of silica aerogel. [ABSTRACT FROM AUTHOR]

Prion fibrils, which are a hallmark for neurodegenerative diseases, have recently been found to exhibit the structural diversity that governs disease pathology. Despite our recent finding concerning the role of the disease-specific structure of prion fibrils in determining their elastic properties, the mechanical deformation mechanisms and fracture properties of prion fibrils depending on their structures have not been fully characterized. In this work, we have studied the tensile deformation mechanisms of prion and non-prion amyloid fibrils by using steered molecular dynamics simulations. Our simulation results show that the elastic modulus of prion fibril, which is formed based on left-handed β-helical structure, is larger than that of non-prion fibril constructed based on right-handed β-helix. However, the mechanical toughness of prion fibril is found to be less than that of non-prion fibril, which indicates that infectious prion fibril is more fragile than non-infectious (non-prion) fibril. Our study sheds light on the role of the helical structure of amyloid fibrils, which is related to prion infectivity, in determining their mechanical deformation mechanisms and properties. [ABSTRACT FROM AUTHOR]

The geochemistry of CO2-rich springs and wells was monitored as a natural analogue study of CO2 leakage into shallow aquifers. In result, within the relatively small study area, diluted CO2-rich waters (DCWs), concentrated CW (CCW), and ordinary groundwaters were observed. DCWs showed an exceptionally low pH (mean 4.8) and low EC (mean 150 μS/cm). The low pH and EC as well as the time-invariant geochemistry of DCWs were probably due to continuous CO2 inputs into the open system, which had a short reaction time and rarely consisted of reactive minerals. DCWs showed the low concentrations of SiO2 (mean 20.4 mg/L) and the average tritium concentration of 3.4 TU, which indicates the low CO2–H2O–rock interaction. In addition, δ 13 C CO 2 g in equilibrium with water was estimated using the mass balance equation and δ13CDIC measured in water samples. The results of the stable carbon isotope analysis showed that the CO2 originated from a deep-seated source to the shallow DCW aquifer (<80 m deep below the surface), whereas the deeper CCW aquifer was affected by soil organic CO2 near the surface. To detect the CO2 leakage from CO2 storage sites, the geochemistry of shallow aquifers should be monitored. This study result suggests that at least pH, EC, DIC, and carbon isotopes should be monitored because the monitoring of pH is helpful in an aquifer with low buffering capacity; while EC can be low despite CO2 leakage and the subsequently low pH at early stages, depending on the subsurface environment. Above all, this present study indicates that understanding the characteristics of aquifer conditions is of great importance for CO2 leakage detection. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the correlations between T2 value, T2* value, and histological grades of degenerated human articular cartilage. Materials and methods: T2 mapping and T2* mapping of nine tibial osteochondral specimens were obtained using a 3-T MRI after total knee arthroplasty. A total of 94 ROIs were analyzed. Histological grades were assessed using the David-Vaudey scale. Spearman's rho correlation analysis and Pearson's correlation analysis were performed. Results: The mean relaxation values in T2 map with different histological grades (0, 1, 2) of the cartilage were 51.9 ± 9.2 ms, 55.8 ± 12.8 ms, and 59.6 ± 10.2 ms, respectively. The mean relaxation values in T2* map with different histological grades (0, 1, 2) of the cartilage were 20.3 ± 10.3 ms, 21.1 ± 12.4 ms, and 15.4 ± 8.5 ms, respectively. Spearman's rho correlation analysis confirmed a positive correlation between T2 value and histological grade (ρ = 0.313, p < 0.05). Pearson's correlation analysis revealed a significant negative correlation between T2 and T2* ( r = −0.322, p < 0.05). Although T2* values showed a decreasing trend with an increase in cartilage degeneration, this correlation was not statistically significant in this study (ρ = −0.192, p = 0.129). Conclusions: T2 mapping was correlated with histological degeneration, and it may be a good biomarker for osteoarthritis in human articular cartilage. However, the strength of the correlation was weak (ρ = 0.313). Although T2* values showed a decreasing trend with an increase in cartilage degeneration, the correlation was not statistically significant. Therefore, T2 mapping may be more appropriate for the initial diagnosis of articular cartilage degeneration in the knee joint. Further studies on T2* mapping are needed to confirm its reliability and mechanism in cartilage degeneration. [ABSTRACT FROM AUTHOR]

30BO-70VO binary-system glass was prepared, and variations in structural and electrical property were examined using crystallization. While different related research studies exist, few have evaluated the variations in the structure and properties with changes in the crystallization rate. 30BO-70VO glass was annealed in the graphite mold above the glass transition temperature for 2 h and heat-treated at each crystallization temperature for 3 h. 30BO-70VO glass showed predominantly electronic conductive characteristic. FTIR was preferentially used for analyzing the structural changes of B-O bond after crystallization, while XRD was utilized to verify the inferred changes in the structure array (BO + VO ↔ BO + 2VO). Structural changes induced by heat treatment were confirmed by analyzing the molecular volume determined from the sample density, and conductance was measured to correlate structural and property changes. Conductivity is discussed based on the migration of vanadate ions with different valence states because of the increase in VO crystallinity at 130°C, which, however, was not observed at 170°C. After VO structures were reinforced, a 1.8-fold increase in conductance was observed (as compared to the annealed sample) after crystallization at 130°C for 3 h. [ABSTRACT FROM AUTHOR]

Mitigation and control of borehole pressure at the bottom of an injection well is directly related to the effective management of well injectivity during geologic carbon sequestration activity. Researchers have generally accepted the idea that high rates of CO injection into low permeability strata results in increased bottom-hole pressure in a well. However, the results of this study suggested that this is not always the case, due to the occurrence of localized salt precipitation adjacent to the injection well. A series of numerical simulations indicated that in some cases, a low rate of CO injection into high permeability formation induced greater pressure build-up. This occurred because of the different types of salt precipitation pattern controlled by buoyancy-driven CO plume migration. The first type is non-localized salt precipitation, which is characterized by uniform salt precipitation within the dry-out zone. The second type, localized salt precipitation, is characterized by an abnormally high level of salt precipitation at the dry-out front. This localized salt precipitation acts as a barrier that hampers the propagation of both CO and pressure to the far field as well as counter-flowing brine migration toward the injection well. These dynamic processes caused a drastic pressure build-up in the well, which decreased injectivity. By modeling a series of test cases, it was found that low-rate CO injection into high permeability formation was likely to cause localized salt precipitation. Sensitivity studies revealed that brine salinity linearly affected the level of salt precipitation, and that vertical permeability enhanced the buoyancy effect which increased the growth of the salt barrier. The porosity also affected both the level of localized salt precipitation and dry-out zone extension depending on injection rates. High temperature injected CO promoted the vertical movement of the CO plume, which accelerated localized salt precipitation, but at the same time caused a decrease in the density of the injected CO. The combination of these two effects eventually decreased bottomhole pressure. Considering the injectivity degradation, a method is proposed for decreasing the pressure build-up and increasing injectivity by assigning a 'skin zone' that represents a local region with a transmissivity different from that of the surrounding aquifer. [ABSTRACT FROM AUTHOR]

During the operation of a PEMFC, the polymer membrane is degraded by electrochemical reactions and mechanical stresses. We investigated the effects of repeated electrochemical and mechanical degradations in a membrane. For mechanical degradation, the membrane and MEA were repeatedly subjected to wet/dry cycles; for electrochemical degradation, the cell was operated under open-circuit voltage (OCV)/low-humidity conditions. The repeated wet/dry cycles led to a decrease in the mechanical strength of the membrane. When the MEA was degraded electrochemically, repeated wet/dry cycling resulted in the formation of pinholes in the membrane. In the case of different MEAs that were first degraded electrochemically, the extents of their hydrogen crossover currents increased due to repeated wet/dry cycling being different. Therefore, these results indicated that the membrane durability could be evaluated by these methods of repeated electrochemical degradation and wet/dry cycles. [ABSTRACT FROM AUTHOR]

An accelerated single cell test and single electrode cell test were carried out to investigate membrane degradation by Pt dissolved/deposited on the membrane. For a cell operating under accelerated conditions (OCV, 90°C, anode RH 0%, cathode O2 supply), MEA analyses revealed that Pt particles were deposited in the membrane at the anode side, with a decrease in F, O, and C content near the anode side of the membrane. Dissolved Pt from the cathode showed that Pt existed mainly in the form of Pt2+ ionic species. Oxygen and hydrogen helped Pt dissolution from the cathode and Pt deposition in the membrane, respectively. Radical formation on deposited Pt in the membrane was detected by electron spin resonance (ESR). Fluoride emission rate (FER, an indicator of membrane degradation rate) increased with an increase in the amount of Pt in the membrane. [ABSTRACT FROM AUTHOR]

We investigated the hepatic effects of daidzein on the 7,12-dimethylbenz(a)anthracene (DMBA)-induced enzymatic activity and expression of CYP1A1 and CYP1B1 in mice. Daidzein was administered orally to mice at 5 or 25 mg/kg BW for three weeks, after which DMBA (34 mg/kg BW) was administered intragastrically twice a week for two weeks. Twenty-four hours after the last DMBA treatment, the mice were sacrificed. DMBA induced CYP1 activity as well as the expression of CYP1A1 and CYP1B1. The catalytic activity of CYP1 enzymes was determined as 7-ethoxyresorufin-O-deethylase (EROD) activity. Each of these effects was significantly reduced by daidzein; however, the reduction was more pronounced for CYP1A1. Daidzein also exerted a negative effect on the transcription of CYP1A1 by AhR, similar to its effect on CYP1A1. The AhR-dependent inhibition of CYP1 by daidzein may explain the anticancer effects of daidzein. [ABSTRACT FROM AUTHOR]

The springs of Jeju Island have been studied since 1999. However, previous studies did not provide a systematic analysis of survey results. Thus, we performed a systematic analysis of the groundwater flow system using cluster analysis of discharge variables, i.e., discharge rate, electrical conductivity (EC), and temperature, at 121 springs. The 121 springs were categorized into nine major groups based on discharge rates and ten groups based on EC. Springs in groups 1, 2, and 3 in discharge cases had peak discharge rates in September, October, and occasionally in November, following the rainy season. Other springs showed complex seasonal variation in discharge rates. Springs in groups 4–1, 4–3, 5–2, 9–1, and 9–2 had peak discharge rates in winter (December–February). The results of classification by EC were directly correlated with the absolute values of and seasonal variation in EC. Based on EC, springs in group 1 had relatively low EC of > 500 μS/cm in general. The highest EC at each spring in group 1 was 110–18,000 μS/cm. Coastal springs generally had higher EC than did springs located inland. The relation between discharge rate and EC was of interest. At some springs, discharge rate and EC were proportional, especially in winter. The proportionality between discharge and EC cannot be explained by the conventional groundwater management model of Jeju Island. To explain this proportionality, we examined the results of previous studies with regard to geological features, well locations, hydraulic head and hydraulic gradient distributions, and vertical reduction in groundwater EC within the zone influenced by saline water. We then proposed a hypothetical regional conceptual model of groundwater flow for Jeju Island. More precise studies are needed to clarify the relationships among responses at surveyed springs, hydraulic features in coastal areas, and the regional conceptual model for groundwater circulation on Jeju Island. [ABSTRACT FROM AUTHOR]

A novel solid polymer electrolyte (pore-gel SPE) has been found to provide superior SPE having a high conductivity, good mechanical strength and low solution leakage. This pore-gel SPE was prepared from gelation in pores of polymer membrane with electrolyte solution including solvent. The conductivity of pore-gel type PVDF-HFP/ TEABF4 (Tetraethylammomium tetrafluoroborate) membrane can reach 1.6×10-1 Scm-1. The tensile strength of this membrane was 4,000 kPa, which is about 23 times larger than that of gel-type SPE with the same composition. Poregel SPE reduced solution leakage to 0%, compared with 2% of hybrid-type SPE after 2.0 hr leakage test in PVDFHFP/ TEABF4 membrane. [ABSTRACT FROM AUTHOR]

Pain arising from cancer tends to be chronic and chemotherapy of cancer pain usually requires narcotics. Most injectable narcotics, however, have short half-lives (T1/2) and require either continuous infusion or repeated frequent injections which are both inconvenient and uncomfortable. An extended-release formulation of morphine sulfate (Depo/Morphine) in a lipid-based drug-delivery system was characterized and tested in an animal model. The encapsulation efficiency was 53% +/- 4%, and the in vitro release T1/2 in human plasma at 37 degrees C was 12.1 +/- 1.1 days. Following s.c. administration of Depo/Morphine, the total amount of morphine remaining at the s.c. injection site decreased monoexponentially with a T1/2 value of 2.59 +/- 0.16 days as compared with 0.46 +/- 0.04 h following the injection of unencapsulated morphine. The morphine concentration in plasma also decreased monoexponentially with a T1/2 value of 8.33 +/- 2.13 days as compared with 0.45 +/- 0.21 h for unencapsulated morphine. Cataleptic behavior was observed in mice injected with unencapsulated morphine but not in those given an identical dose of morphine in the form of Depo/Morphine. In conclusion, Depo/Morphine has potential as an extended-release formulation of morphine and may be useful in chemotherapy of cancer pain as well as in maintenance therapy of narcotic addicts. [ABSTRACT FROM AUTHOR]

Optimal anticancer treatment with cell cycle phase-specific antimetabolites requires a sustained maintenance of cytotoxic drug levels. However, drugs that can be administered intrathecally have short half-lives in cerebrospinal fluid (CSF) and require repeated administrations by lumbar punctures, which are painful and inconvenient. Implantable pumps are expensive and require surgery. In a rat model, a lipid-based formulation of methotrexate (Depo/methotrexate) was tested for extended maintenance of therapeutic CSF concentration after a single injection. The half-life of methotrexate in CSF after an intracisternal injection of Depo/methotrexate was 5.4 days compared to 0.30 days for unencapsulated methotrexate. This 18-fold increase in methotrexate half-life may make Depo/methotrexate useful for intrathecal chemotherapy of neoplastic meningitis. [ABSTRACT FROM AUTHOR]

The general disease burden associated with the restrictive spirometric pattern (RSP) is substantial. However, the impact of RSP by its severity on general health problems and quality of life has not been well elucidated. This study aimed to analyse nutrition, physical activity, and quality of life in subjects who participated in the Korea National Health and Nutrition Examination Survey 2007–2016 according to severity of RSP. Participants were classified as subjects with normal spirometry, those with mild-to-moderate RSP, and those with severe RSP. Poor quality of life was defined as 25th percentile value on the EuroQoL five dimensions (Eq5D) questionnaire index, i.e., 0.90. This study included 23,615 subjects composed of 20,742 with normal spirometry, 2758 with mild-to-moderate RSP, and 115 with severe RSP. The subjects with severe RSP were more likely to have attained lower education levels, had a lower total caloric intake, had less physical activity, had experienced a higher prevalence of comorbidities, and poorer quality of life than those with normal spirometry (P < 0.001 for all). In multivariable analysis, subjects with a mild-to-moderate RSP and severe RSP were more likely to show decreased total calories (coefficient for change in calorie = − 56.6 kcal and − 286.7 kcal, respectively) than those with normal spirometry; subjects with mild-to-moderate RSP and those with severe RSP were 1.26 times and 1.96 times more likely, respectively, to have a poorer quality of life than those with normal spirometry. Additionally, subjects with mild-to-moderate RSP and those with severe RSP were 0.84 times and 0.36 times less likely, respectively, to have high-intensity physical activity than those with normal spirometry in univariable analysis. The trends of a poorer quality of life and physical activity were only significant in the male subgroups. In conclusion, our study revealed that the severity of general health problems and quality of life reductions are correlated with the severity of RSP, especially in males. [ABSTRACT FROM AUTHOR]