Polytypic Two-Dimensional FeAs with High Anisotropy.

In the realm of two-dimensional (2D) crystal growth, the chemical composition often determines the thermodynamically favored crystallographic structures. This relationship poses a challenge in synthesizing novel 2D crystals without altering their chemical elements, resulting in the rarity of achieving specific crystallographic symmetries or lattice parameters. We present 2D polymorphic FeAs crystals that completely differ from bulk orthorhombic FeAs (Pnma), differing in the stacking sequence, i.e., polytypes. Preparing polytypic FeAs outlines a strategy for independently controlling each symmetry operator, which includes the mirror plane for 2Q-FeAs (I4/mmm) and the glide plane for 1Q-FeAs (P4/nmm). As such, compared to bulk FeAs, polytypic 2D FeAs shows highly anisotropic properties such as electrical conductivity, Young's modulus, and friction coefficient. This work represents a concept of expanding 2D crystal libraries with a given chemical composition but various crystal symmetries.

Extreme Ion-Transport Inorganic 2D Membranes for Nanofluidic Applications.

Inorganic 2D materials offer a new approach to controlling mass diffusion at the nanoscale. Controlling ion transport in nanofluidics is key to energy conversion, energy storage, water purification, and numerous other applications wherein persistent challenges for efficient separation must be addressed. The recent development of 2D membranes in the emerging field of energy harvesting, water desalination, and proton/Li-ion production in the context of green energy and environmental technology is herein discussed. The fundamental mechanisms, 2D membrane fabrication, and challenges toward practical applications are highlighted. Finally, the fundamental issues of thermodynamics and kinetics are outlined along with potential membrane designs that must be resolved to bridge the gap between lab-scale experiments and production levels.

Bacterial microbiota profiling of oyster mushrooms (Pleurotus ostreatus) based on cultivation methods and distribution channels using high-throughput sequencing.

The annual consumption and production of oyster mushrooms (Pleurotus ostreatus) have continued to rise due to its nutritive and health-promoting benefits. Cultivated mushrooms are mostly grown in small to medium-scaled scale production plants that present hygienic challenges which could, in turn, increase associated foodborne pathogenic outbreaks. The present study aimed to investigate the shift in microbial ecologies of oyster mushrooms from pre-distribution (cultivation in bottles or on shelves) to post-distribution at supermarkets and open-air markets. Aerobic plate counts and coliforms were quantified using traditional microbiological techniques, and the microbiome associated with oyster mushrooms (n = 70) was analyzed using 16S rRNA amplicon sequencing for an enhanced level of bacterial microbiota profiling. Overall, coliforms recovered from pre-distribution bottle-cultivated mushrooms were 1.9 log CFU/g higher (p < 0.05) than that of shelf-cultivated mushrooms. The mean aerobic plate counts of oyster mushrooms distributed to open-air markets was 1.2 log CFU/g higher (p < 0.05) than packaged mushrooms from supermarkets while there were no significant differences in coliform counts. The pattern of bacterial composition differed by post-distribution channels, with oyster mushrooms collected from the open-air markets demonstrating the richest microbiome diversity. An increase in the relative abundance of Enterobacteriaceae (55-68 %) and Pseudomonadaceae (27-35 %) was observed in pre- and post-distribution mushrooms, respectively. However, no distinct bacterial microbiota differences were observed for the different cultivation methods or different geographical locations for each market type. The current findings add to our understanding of the effects of cultivation methods and commercial distribution channels regarding the microbiome of oyster mushrooms and may inform potential intervention strategies for future production and distribution processes. Furthermore, the tandem analyses of culture-dependent and culture-independent methods can provide more comprehensive information than that obtained when using each approach independently.

Neighbor-Aware Non-Orthogonal Multiple Access Scheme for Energy Harvesting Internet of Things.

In a non-orthogonal multiple access (NOMA) environment, an Internet of Things (IoT) device achieves a high data rate by increasing its transmission power. However, excessively high transmission power can cause an energy outage of an IoT device and have a detrimental effect on the signal-to-interference-plus-noise ratio of neighbor IoT devices. In this paper, we propose a neighbor-aware NOMA scheme (NA-NOMA) where each IoT device determines whether to transmit data to the base station and the transmission power at each time epoch in a distributed manner with the consideration of its energy level and other devices' transmission powers. To maximize the aggregated data rate of IoT devices while keeping an acceptable average energy outage probability, a constrained stochastic game model is formulated, and the solution of the model is obtained using a best response dynamics-based algorithm. Evaluation results show that NA-NOMA can increase the average data rate up to 22% compared with a probability-based scheme while providing a sufficiently low energy outage probability (e.g., 0.05).

Unsupervised multi-sense language models for natural language processing tasks.

Existing language models (LMs) represent each word with only a single representation, which is unsuitable for processing words with multiple meanings. This issue has often been compounded by the lack of availability of large-scale data annotated with word meanings. In this paper, we propose a sense-aware framework that can process multi-sense word information without relying on annotated data. In contrast to the existing multi-sense representation models, which handle information in a restricted context, our framework provides context representations encoded without ignoring word order information or long-term dependency. The proposed framework consists of a context representation stage to encode the variable-size context, a sense-labeling stage that involves unsupervised clustering to infer a probable sense for a word in each context, and a multi-sense LM (MSLM) learning stage to learn the multi-sense representations. Particularly for the evaluation of MSLMs with different vocabulary sizes, we propose a new metric, i.e., unigram-normalized perplexity (PPLu), which is also understood as the negated mutual information between a word and its context information. Additionally, there is a theoretical verification of PPLu on the change of vocabulary size. Also, we adopt a method of estimating the number of senses, which does not require further hyperparameter search for an LM performance. For the LMs in our framework, both unidirectional and bidirectional architectures based on long short-term memory (LSTM) and Transformers are adopted. We conduct comprehensive experiments on three language modeling datasets to perform quantitative and qualitative comparisons of various LMs. Our MSLM outperforms single-sense LMs (SSLMs) with the same network architecture and parameters. It also shows better performance on several downstream natural language processing tasks in the General Language Understanding Evaluation (GLUE) and SuperGLUE benchmarks.

Kinetic 2D Crystals via Topochemical Approach.

The designing of novel materials is a fascinating and innovative pathway in materials science. Particularly, novel layered compounds have tremendous influence in various research fields. Advanced fundamental studies covering various aspects, including reactants and synthetic methods, are required to obtain novel layered materials with unique physical and chemical properties. Among the promising synthetic techniques, topochemical approaches have afforded the platform for widening the extent of novel 2D materials. Notably, the synthesis of binary layered materials is considered as a major scientific breakthrough after the synthesis of graphene as they exhibit a wide spectrum of material properties with varied potential applicability. In this review, a comprehensive overview of the progress in the development of metastable layered compounds is presented. The various metastable layered compounds synthesized from layered ternary bulk materials through topochemical approaches are listed, followed by the descriptions of their mechanisms, structural analyses, characterizations, and potential applications. Finally, an essential research direction concerning the synthesis of new materials is indicated, wherein the possible application of topochemical approaches in unprecedented areas is explored.

A study on the characteristics of pollutant release and transfer registers (PRTRs) and cancer incidence rates in Korea.

This study aims to identify the past decade's trend of harmful chemical emissions, which have been disclosed on the website as open information. During the past 10 years, the number of places of business, examined for their harmful chemical emissions, increased about 1.3× and their emissions went up 1.1×. More than 50% of total emissions have occurred in the top three areas, and the largest emissions were from xylene and toluene for the past 10 years. Among the total emissions, the group 1 carcinogen decreased from 5.3 to 2.1%, and among group 1 in particular, trichloroethylene and benzene accounted for more than 80%. Although it was impossible to find out any relationship between major cancers' development and the results of carcinogen emissions, considering the features of carcinogens emitted in specific areas, more research is needed to find out relationship. And, it is necessary to come up with proactive policies to reduce harmful chemical substances which can affect human health through environmental pollution.

Dopamine D2 receptor-mediated circuit from the central amygdala to the bed nucleus of the stria terminalis regulates impulsive behavior.

Impulsivity is closely associated with addictive disorders, and changes in the brain dopamine system have been proposed to affect impulse control in reward-related behaviors. However, the central neural pathways through which the dopamine system controls impulsive behavior are still unclear. We found that the absence of the D2 dopamine receptor (D2R) increased impulsive behavior in mice, whereas restoration of D2R expression specifically in the central amygdala (CeA) of D2R knockout mice (Drd2-/-) normalized their enhanced impulsivity. Inhibitory synaptic output from D2R-expressing neurons in the CeA underlies modulation of impulsive behavior because optogenetic activation of D2R-positive inhibitory neurons that project from the CeA to the bed nucleus of the stria terminalis (BNST) attenuate such behavior. Our identification of the key contribution of D2R-expressing neurons in the CeA → BNST circuit to the control of impulsive behavior reveals a pathway that could serve as a target for approaches to the management of neuropsychiatric disorders associated with impulsivity.

Correction to: Developing japonica rice introgression lines with multiple resistance genes for brown planthopper, bacterial blight, rice blast, and rice stripe virus using molecular breeding.

In the original publication.

Developing japonica rice introgression lines with multiple resistance genes for brown planthopper, bacterial blight, rice blast, and rice stripe virus using molecular breeding.

Yield losses as a result of biotic stresses by fungi, bacteria, viruses, and insects are a key challenge in most rice cultivation areas. The development of resistant cultivars is considered an efficient and sustainable approach to mitigate rice yield reduction. In the present study, we describe the development of japonica rice introgression lines with multiple resistance genes (MR lines), resistant to four different types of biotic stresses, and compare the agronomic performance, yield, and grain quality parameters of these lines with those of the recurrent parent. A total of nine MR lines were developed by marker-assisted backcrossing, which combined five single-R genes in a japonica background with a minimum of linkage drag. All the MR lines harbored the R genes Bph18 and qSTV11SG and two Pi genes (Pib + Pik) in common, offering resistance to brown planthopper (BPH), rice stripe virus (RSV), and rice blast disease, respectively. In the case of bacterial blight (BB), Xa40 was detected in only five out of the nine and Xa3 was validated in the others. In particular, the five MR lines pyramiding the R genes (Bph18 + qSTV11SG + Pib + Pik) in combination with Xa40 showed stable resistance to all bioassays for BPH, BB, blast, and RSV. The MR lines did not show any negative effects on the main agronomic traits, including yield production and rice grain quality. The lines have significant potential to stabilize rice yield and minimize production costs in disease and pest-prone areas in Korea, through the pyramiding of five R genes using a marker-assisted backcrossing strategy.

Rapid characterization of metabolites in soybean using ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) and screening for α-glucosidase inhibitory and antioxidant properties through different solvent systems.

This work was the first to investigate on the simultaneous characterization of metabolite profiles in soybean using UPLC-ESI-Q-TOF-MS/MS. Twenty two compositions were observed within 14 min from the methanol extract and confirmed as twelve isoflavones of three types and ten soyasaponins (Ab, Af, I-III, αg, ßg, ßa, γg, and γa). Moreover, the patterns of two chemicals showed considerable differences in seven solvent systems by HPLC analysis and their optimal extraction was achieved by 70% methanol (isoflavone: 4102.69 µg/g; soyasaponin: ten peaks). The second abundant isoflavones were detected in 50% methanol (4054.39 µg/g), followed by 30% methanol, 100% methanol, 10% methanol, CH2Cl2, and acetone extracts with 3134.03, 2979.49, 1681.33, 366.19, and 119.00 µg/g, respectively. Soyasaponins exhibited similar tendencies as those of isoflavones. The highest total phenolic was found as 2.10 ± 0.05 mg GAE/g in 70% methanol with remarkable differences by comparing other extracts. Specifically, this extract showed potent α-glucosidase inhibitory (81%) and antioxidant capacities (DPPH: 93% and ABTS: 95%) at a concentration of 1.0 mg/mL. Our results may be contributed to enhancing the value to functional foods and evaluating the secondary metabolites concern to antioxidant properties using solvent system in soybean.

Characterization of metabolite profiles from the leaves of green perilla (Perilla frutescens) by ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry and screening for their antioxidant properties.

The objective of this research was to access the determination of metabolite profiles and antioxidant properties in the leaves of green perilla (Perilla frutescens), where these are considered functional and nutraceutical substances in Korea. A total of 25 compositions were confirmed as six phenolic acids, two triterpenoids, eight flavonoids, seven fatty acids, and two glucosides using an ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) technique from the methanol extract of this species. The individual and total compositions exhibited significant differences, especially rosmarinic acid (10), and linolenic acids (22 and 23) were detected as the predominant metabolites. Interestingly, rosmarinic acid (10) was observed to have considerable differences with various concentrations in three samples (Doryong, 6.38 µg/g; Sinseong, 317.60 µg/g; Bongmyeong, 903.53 µg/g) by UPLC analysis at 330 nm. The scavenging properties against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals also showed potent effects with remarkable differences at a concentration of 100 µg/mL, and their abilities were as follows: Sinseong (DPPH, 86%; ABTS, 90%) > Bongmyeong (71% and 84%, respectively) > Doryong (63% and 73%, respectively). Our results suggest that the antioxidant activities of green perilla leaves are correlated with metabolite contents, especially the five major compositions 10 and 22-25. Moreover, this study may be useful in evaluating the relationship between metabolite composition and antioxidant activity.

EEG-Based Classification of Implicit Intention During Self-Relevant Sentence Reading.

From electroencephalography (EEG) data during self-relevant sentence reading, we were able to discriminate two implicit intentions: 1) "agreement" and 2) "disagreement" to the read sentence. To improve the classification accuracy, discriminant features were selected based on Fisher score among EEG frequency bands and electrodes. Especially, the time-frequency representation with Morlet wavelet transforms showed clear differences in gamma, beta, and alpha band powers at frontocentral area, and theta band power at centroparietal area. The best classification accuracy of 75.5% was obtained by a support vector machine classifier with the gamma band features at frontocentral area. This result may enable a new intelligent user-interface which understands users' implicit intention, i.e., unexpressed or hidden intention.

Implicit agreeing/disagreeing intention while reading self-relevant sentences: A human fMRI study.

The true intentions of humans are sometimes difficult to ascertain exclusively from explicit expressions, such as speech, gestures, or facial expressions. In this experiment, functional magnetic resonance imaging (fMRI) was used to investigate implicit intentions that were generated while a subject was reading self-relevant sentences. Short sentences, which were presented visually, consisted of self-relevant statements and a substantive verb, which indicated sentence polarity as either affirmative or negative. Each sentence was divided into the contents and the sentence ending, and the subjects were asked to respond with either agreement or disagreement after the complete sentence was presented. The overall group analysis suggested that the intention of the sentence response was found even before the reading of the complete sentences. Increased neural activation was found in the left medial prefrontal cortex (MPFC) during feelings of agreement compared to feelings of disagreement during self-relevant decision-making. In addition, according to the sentence ending, the decision of a response activated the frontopolar cortex (FPC) in the switching condition. These findings indicated that the implicit intentions of responses to the given statements were internally generated before an explicit response occurred, and, hence, intentions can be used to predict a subject's future answer.

Variations in label information and nicotine levels in electronic cigarette refill liquids in South Korea: regulation challenges.

BACKGROUND: In South Korea, the consumption of liquid nicotine used in electronic cigarettes has dramatically increased from 4310 L in 2012 to 7220 L in 2013. This study aimed to examine the level of heterogeneity of contents of the labels and discrepancy of the nicotine content between that indicated on the label and the actual values for electronic cigarette liquid refill products in South Korea. METHODS: We purchased 32 electronic cigarette liquid refill products (17 Korean domestic, 15 imported ones) and one pure nicotine product at six different electronic cigarette retail stores in Seoul between May and June 2014. The actual nicotine concentrations of each product were measured by a blinded analyst at Roswell Park Cancer Institute, Buffalo, NY, USA. RESULTS: Three out of 15 imported liquid refill products provided manufacturing dates, while expiration dates were available on eight products. The range of nicotine concentration was from "not detected" to 17.5 mg/mL. Labeling discrepancies of the concentrations ranged from -32.2% to 3.3% among electronic cigarette liquid refill products. The highest concentration (150.3 ± 7.9 mg/mL) was found in a sample labeled as "pure nicotine". CONCLUSIONS: There is no standardization of labelling among electronic cigarette liquids sampled from retail stores and the labels did not accurately reflect the content. One product labeled "pure nicotine" raises concerns, since it may be poisonous to consumers, especially to children. This study revealed the urgent need for the development of product regulations in South Korea.

Association of urinary 3-phenoxybenzoic acid levels with self-reported depression symptoms in a rural elderly population in Asan, South Korea.

OBJECTIVES: This study aimed to evaluate the association between presence of depression symptoms and the exposure level to insecticides among aged population in rural area, determined via measured levels of urinary 3-phenoxybenzoic acid (3-PBA), after controlling for socioeconomic confounding factors. METHODS: Using a cross-sectional study design, we randomly recruited participants for our study (161 male and 239 female) from rural areas of Asan, Chungnam, Korea. Environmental risk factor exposure was assessed using a questionnaire, and gas chromatography- mass spectrometry was used to analyze urinary 3-PBA levels. We used a logistic regression analysis to assess the association of urinary 3-PBA levels with the presence of self-reported depression symptoms. RESULTS: After controlling for creatinine levels, the median (interquartile range) concentration of 3-PBA was approximately 1.5 times (p<0.05) higher among female (1.54 [0.90 to 2.35]) µg/g) than among male (1.06 [0.64 to 1.81] µg/g). Our study found that among female participants, the unit increase in 3-PBA levels exhibited a likely positive association (odds ratio, 1.12; 95% confidence interval, 1.00 to 1.25) with an increased risk of presence of self-reported depression symptoms, after adjusting for socioeconomic insurance type, daily physical condition, marital status, smoking status, and age. CONCLUSIONS: Given our finding of a potential association between the presence of selfreported depression symptoms and 3-PBA levels, precautions should be considered to minimize exposure to insecticides and thus protect the health of aged residents in rural areas.

Nicotine levels in electronic cigarette refill solutions: A comparative analysis of products from the U.S., Korea, and Poland.

BACKGROUND: Electronic cigarettes vaporize nicotine dissolved in glycerine and/or propylene glycol (e-liquid). Due to a lack of regulations, e-liquids may contain inaccurately labelled nicotine levels. Our aim was to test nicotine levels in samples of e-liquids from three countries. METHODS: We measured nicotine concentration in 32, 29 and 30 e-liquids purchased between 2013 and 2014 from locations in the United States (US), South Korea, and Poland, respectively. RESULTS: Nicotine concentration in the US products varied from 0 to 36.6 mg/mL. Traces of nicotine were found in three US products labelled as 'nicotine free'. Two-thirds of South Korean products did not contain detectable amounts of nicotine, whereas nicotine concentration in other products varied from 6.4±0.7 to 150.3±7.9 (labelled as 'pure nicotine') mg/mL. In products from Poland, nicotine concentration varied from 0 to 24.7±0.1 mg/mL. Overall, we found significant discrepancies (>20%) in the labelled nicotine concentrations in 19% of analysed e-liquids. CONCLUSION: Most of the analysed samples had no significant discrepancies in labelled nicotine concentrations and contained low nicotine levels. However some products labelled as 'nicotine-free' had detectable levels of the substance, suggesting insufficient manufacturing quality control. We identified a single product labelled as 'pure nicotine' which contained significantly higher concentration of the drug, increasing the risk of accidental poisoning. The study reveals the need for quality standards of these new nicotine containing products.

Effects of allelic variations in starch synthesis-related genes on grain quality traits of Korean nonglutinous rice varieties under different temperature conditions.

Influences of allelic variations in starch synthesis-related genes (SSRGs) on rice grain quality were examined. A total of 187 nonglutinous Korean rice varieties, consisting of 170 Japonica and 17 Tongil-type varieties, were grown in the field and in two greenhouse conditions. The percentages of head rice and chalky grains, amylose content, alkali digestion value, and rapid visco-analysis characteristics were evaluated in the three different environments. Among the 10 previously reported SSRG markers used in this study, seven were polymorphic, and four of those showed subspecies-specific allele distributions. Six out of the seven polymorphic SSRG markers were significantly associated with at least one grain quality trait (R (2) > 0.1) across the three different environments. However, the association level and significance were markedly lower when the analysis was repeated using only the 170 Japonica varieties. Similarly, the significant associations between SSRG allelic variations and changes in grain quality traits under increased temperature were largely attributable to the biased allele frequency between the two subpopulations. Our results suggest that within Korean Japonica varieties, these 10 major SSRG loci have been highly fixed during breeding history and variations in grain quality traits might be influenced by other genetic factors.

Agronomic and genetic analysis of Suweon 542, a rice floury mutant line suitable for dry milling.

BACKGROUND: Producing rice flour of good quality by dry milling is necessary to reduce milling costs and promote the processed rice food industry. This study was conducted to evaluate the dry milling properties of Suweon 542, a floury endosperm mutant, and identify the chromosomal region responsible for the floury endosperm characteristics. RESULTS: Compared with the wild type, after dry milling process, the grain hardness of Suweon 542 was significantly lower because of its round and loosely packed starch granules. Also, the flour of Suweon 542 had significantly smaller particles and less damaged starch than Namil and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar. Considering that the yield loss of Suweon 542 due to its floury endosperm was largely compensated for by an increased number of spikelets per panicle, Suweon 542 has potential value as a raw material for rice flour production. Association analysis using 70 genome-wide SSR markers and 94 F2 plants derived from Suweon 542/Milyang 23 showed that markers on chromosome 5 explained a large portion of the variation in floury grains percentage (FGP). Further analysis with an increased number of SSR markers revealed that the floury endosperm of Suweon 542 was directed by a major recessive locus, flo7(t), located in the 19.33-19.86 Mbp region of chromosome 5, with RM18639 explaining 92.2% of FGP variation in the F2 population. CONCLUSIONS: The floury endosperm of Suweon 542 is suitable for dry milling, with a small flour particle size and low damaged starch content. Further physical mapping of flo7(t), the floury endosperm locus of Suweon 542, would facilitate efficient breeding of rice cultivars with proper dry milling adaptability that can be used in the processed rice food industry.

OsSNDP1, a Sec14-nodulin domain-containing protein, plays a critical role in root hair elongation in rice.

Rice is cultivated in water-logged paddy lands. Thus, rice root hairs on the epidermal layers are exposed to a different redox status of nitrogen species, organic acids, and metal ions than root hairs growing in drained soil. To identify genes that play an important role in root hair growth, a forward genetics approach was used to screen for short-root-hair mutants. A short-root-hair mutant was identified and isolated by using map-based cloning and sequencing. The mutation arose from a single amino acid substitution of OsSNDP1 (Oryza sativa Sec14-nodulin domain protein), which shows high sequence homology with Arabidopsis COW1/AtSFH1 and encodes a phosphatidylinositol transfer protein (PITP). By performing complementation assays with Atsfh1 mutants, we demonstrated that OsSNDP1 is involved in growth of root hairs. Cryo-scanning electron microscopy was utilized to further characterize the effect of the Ossndp1 mutation on root hair morphology. Aberrant morphogenesis was detected in root hair elongation and maturation zones. Many root hairs were branched and showed irregular shapes due to bulged nodes. Many epidermal cells also produced dome-shaped root hairs, which indicated that root hair elongation ceased at an early stage. These studies showed that PITP-mediated phospholipid signaling and metabolism is critical for root hair elongation in rice.