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While microplastic analysis in aquatic systems is rather well standardized, the determination of microplastics in terrestrial samples has been less explored. Here, we review methods for microplastic analysis, with focus on sampling location and design, soil quantity, sampling depth and equipment, and sample handling and preservation. We found that the random sampling design can be used to collect a representative sample. Stainless steel shovels or soil augers were the most common tools for collecting topsoil, from 0 to 30 cm. Deep soil samples, of more than 100 cm depth, can only be obtained using a core drill. The number of soil samples collected in the field depends on the available budget and instruments for microplastic analysis. For example, if a micro-Fourier transform infrared microscope is used for analysis, soil samples as small as 15.0 g per point can be collected. Once the soils are collected, they can be stored in non-plastic containers, e.g., aluminum bags, to reduce contamination. [ABSTRACT FROM AUTHOR]

The bean bug Riptortus pedestris causes major damage to soybean and has become a serious problem due to its high resistance to insecticides. To address this problem, this study aimed to select the most effective entomopathogenic fungi for the control of R. pedestris. Selection was performed through the evaluation of virulence, thermotolerance, and UV‐B tolerance of fungal isolates against R. pedestris and conidial production on grain medium. The pathogenicity of 30 Beauveria bassiana isolates and 30 Metarhizium anisopliae isolates was evaluated, and pathogenicity was confirmed in all but 3 isolates of B. bassiana. Among the 57 isolates, 11 exhibited high virulence. Of these 11 isolates, B. bassiana JB13G1W1 and M. anisopliae CB6T1G1 and JB12R3G1 showed the highest virulence of more than 80%. The conidial production of all fungal isolates in millet grain medium was good, ranging from 108 to 109 conidia/g. The UV‐B tolerance and thermotolerance of the 57 isolates varied according to the isolate, and those of M. anisopliae isolates were slightly higher than those of B. bassiana. As a result of comparative evaluation of the virulence, conidial production, thermotolerance, and UV‐B tolerance of fungal isolates, B. bassiana JB13G1W1 and M. anisopliae CB6T1G1 and JB12R3G1 were selected as excellent fungal isolates for the control of R. pedestris. Among them, B. bassiana JB13G1W1 showed the highest virulence, with LC50 and LT50 values of 7.86 × 105 conidia/mL and 5.24 days at 108 conidia/mL, respectively. The most effective growth stage to control R. pedestris with B. bassiana JB13G1W1 was 2nd‐instar nymphs. [ABSTRACT FROM AUTHOR]

A new stable transition-metal trihydride (ScH3) molecular nanowire was recently reported by Li et al. [J. Am. Chem. Soc. 139, 6290–6293 (2017)]. Of the two typical structures (T–ScH3 and O–ScH3), T–ScH3 is more stable than O–ScH3. However, the reason why O–ScH3 is less stable than T–ScH3 was not known. Using Perdew–Burke–Ernzerhof (PBE), PBE+U, SCAN, and HSE06, as well as crystal orbital Hamilton populations (COHPs), we investigate the orbital-projected band structures and chemical bonding of T–ScH3 and O–ScH3. It is found that the energies calculated by PBE, SCAN, and HSE06 indeed reveal that T–ScH3 is more stable than O–ScH3, and there is no occupied antibonding state at the Fermi level of the COHP curves of T–ScH3, supporting the stable Sc–H bonding of T–ScH3. To the contrary, the Sc–H bonding of O–ScH3 is unstable because there exist occupied antibonding states at the Fermi level of the COHP curves of O–ScH3. We found that the results of PBE+U are consistent with those of PBE, SCAN, and HSE06 in the case of U < Uc. However, when U > Uc, the results of PBE+U are opposite to those of PBE, SCAN, and HSE06. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a toxic heavy metal that is widely present in the environment. Renal proximal tubule disorder is the main symptom of Cd chronic poisoning. Our previous study demonstrated that Cd inhibits the total activities of peroxisome proliferator-activated receptor (PPAR) transcription factors in human and rat proximal tubular cells. In this study, we investigated the involvement of PPAR in Cd renal toxicity using the HK-2 human proximal tubular cell line. Among PPAR isoform genes, only PPARD knockdown significantly showed resistance to Cd toxicity in HK-2 cells. The transcriptional activity of PPARδ was decreased not only by PPARD knockdown but also by Cd treatment. DNA microarray analysis showed that PPARD knockdown changed the expression of apoptosis-related genes in HK-2 cells. PPARD knockdown decreased apoptosis signals and caspase-3 activity induced by Cd treatment. PPARD knockdown did not affect the intracellular Cd level after Cd treatment. These results suggest that PPARδ plays a critical role in the modification of susceptibility to Cd renal toxicity and that the apoptosis pathway may be involved in PPARδ-related Cd toxicity. [ABSTRACT FROM AUTHOR]

Aggregation of profilin-1 (PFN1) causes a fatal neurodegenerative disease, familial amyotrophic lateral sclerosis (fALS). Histidine (His) tautomerism has been linked to the formation of fibril aggregation causing neurodegenerative disease. Characterization of intermediate species that form during aggregation is crucial, however, this has proven very challenging for experimentalists due to their transient nature. Hence, molecular dynamics (MD) simulations have been performed on the His tautomeric isomers εε, εδ, δε, and δδ of PFN1 to explain the structural changes and to correlate them with its aggregation propensity. MD simulations show that His133 presumably plays a major role in the aggregation of PFN1 upon His tautomerism compared to His119. Further, the formation of a new 3 10 -helix is observed in εε and δε but 3 10 -helix is not observed in δδ and εδ isomers. In addition, our findings unveil that β-sheet dominating conformations are observed in His119(δ)-His133(δ) δδ isomer of PFN1 with significant antiparallel β-sheets between residues T15-G23, S29-A33, L63-L65, Q68-S76, F83-T89, T97-T105, and K107-K115, suggesting a novel aggregation mechanism possibly occur for the formation of PFN1 aggregates. Overall, these results propose that MD simulations of PFN1 His tautomers can provide a detailed microscopic understanding of the aggregation mechanisms which are hard to probe through experiments. [ABSTRACT FROM AUTHOR]

Accessory minerals in granitic rocks are unlikely significant radionuclide contributions to groundwater due to their remarkable durability. However, accessory minerals incorporating U and Th may suffer structural damages due to the radioactivity and become highly susceptible to alteration. This study investigates geochemistry coupled with textural analysis of the U–Th bearing accessory minerals using a field emission scanning electron microscope and an electron probe micro-analyzer. Altered zircons with numerous open structures related to the radioactive decay show higher contents of U and Th and low analytical totals. Some thorites show high contents of U and non-formula elements due to the hydrothermal alteration in the metamicted thorite. The cerianite including U occurs as micro-veinlet in fracture with trace of Fe and Mn oxides, which indicates secondary phase formation from the decomposed accessory minerals in an oxidizing environment. Some accessory minerals with the high content of U and Th have been found in Mesozoic granite terrain in South Korea, where high concentration levels of radionuclide in groundwater were also reported. The leaching of U may be more likely when the accessory minerals are highly metamicted or altered as found in our samples. The altered zircon and thorite of the study area could be major carriers of radioelement in Mesozoic granitic aquifers where the occurrence of soluble U-minerals has not been reported. [Display omitted] • High radionuclides concentration in groundwater poses a threat to human health. • Accessary minerals can enrich groundwater with radionuclides in granite aquifers. • Altered zircons contain high U and Th levels with open structures. • Thorites show elevated U levels and non-formula elements due to alteration. • Metamicted and/or altered accessory minerals increase uranium leaching potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • Groundwater Deficit (GWD) highlights delayed response to precipitation decline. • GWD characterizes and quantifies groundwater drought, including spatial extent. • GWD identifies thirteen drought events over a two-decade span in South Korea. Although South Korea is frequently subjected to monsoons, the shortage of summer monsoons and relatively dry spring and winter seasons cause droughts in the Korean Peninsula. Since the late 1960s, severe droughts in South Korea have encouraged extensive groundwater development for agricultural and economic growth. Therefore, identifying and estimating the impact of droughts on the country's groundwater resources is crucial for establishing policies and regulations on groundwater exploitation and recharge. Current drought management of the country relies on a meteorological drought index. However, these estimates lack a comprehensive understanding of absolute drought severity and propagation. This study aims to develop a quantitative method for calculating the frequency and severity of groundwater droughts based on the Groundwater Deficit (GWD) derived from NASA's Gravity Recovery and Climate Experiment (GRACE) mission data. The estimated annual GWD in mass over the country ranges from -0.07 km3 to 0.04 km3, with a trend in the mass of -1.60×10−3 km3/year from 2002 to 2021. Thirteen groundwater drought events were identified based on GWD. Among those, the highest drought severities recorded in 2015 and 2019 were -34.27 km3 months and -55.38 km3 months, respectively. Monthly deficits define the quantity of water required to restore normal groundwater storage conditions. Hence, the minimum and average days to recover from groundwater droughts were estimated based on the strength of the storage-based approaches. The GWD approach aligns with meteorological drought databases with a time lag. It illustrates the transition from meteorological drought to groundwater drought, along with their onset, cessation, propagation, instantaneous severity, and peak magnitude. [ABSTRACT FROM AUTHOR]

Plastic particles of less than 5 mm size, referred as microplastics, have recently become a major environmental issue. While microplastics are well known in marine and lake systems, there have been less investigations in soils and groundwater. Here we review the origin, shape, impact, and mitigation strategies of soil and groundwater microplastics. We found that littering is the main origin of microplastics in global topsoils, while greenhouses are the main source of microplastics in South Korea. Fibers and pellets are dominant microplastic shapes in soil and groundwater. Microplastic contamination of soil and groundwater is detrimental to human health, plants, nematodes, earthworms, and soil properties. Remediation methods include pyrolysis, replacing plastics by biodegradable plastics, plastic filtration, and subsequent chemical or biological degradation. [ABSTRACT FROM AUTHOR]

Monoclinic scheelite bismuth vanadate is an efficient photocatalyst for water splitting. In this paper, we perform DFT + U calculations to investigate the structural, electronic, and optical properties, water adsorption and the oxygen evolution reaction processes on BiVO4 (001) and BiVO4 (110) surfaces in acidic medium both in the gas and solution (water) phases. The structural, electronic, optical, and water adsorption properties reveal that BiVO4 (001) surface is energetically more stable than BiVO4 (110) surface in vacuum. On other hand, the water oxidation mechanisms reveal that BiVO4 (110) surface in water and in strained form in vacuum is energetically more stable than BiVO4 (001) surface in water and in strained form in vacuum both U = 0 and 2.1 V. The free energy of adsorption for all systems at U = 2.1 V reduce about 2 times than that at U = 0 V. Such analyzes provide important insights into the role of different facets on BiVO4 surface for photocatalytic reactions. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is an environmental contaminant that causes renal toxicity. We have previously demonstrated that Cd induces renal toxicity by altering transcriptional activities. In this study, we show that Cd markedly inhibited the activity of transcription factor MEF2A in HK‐2 human proximal tubule cells, which generated significant cytotoxicity in the cells. This reduction in the nuclear levels of MEF2A protein may be involved in the Cd‐induced inhibition of MEF2A activity. We also demonstrate that one of the glucose transporters, GLUT4, was downregulated not only by Cd treatment but also by MEF2A knockdown. Knockdown of SLC2A4, encoding GLUT4, eliminated both cell viability and Cd toxicity. Cd treatment or SLC2A4 deficiency reduced the cellular concentration of glucose. Therefore, the suppression of SLC2A4 expression, which mediates the reduction in cellular glucose, is involved in Cd toxicity. The Cd toxicity induced by the reduction in GLUT4 may be associated with a reduction of cellular ATP levels in HK‐2 cells. The levels of Slc2a4 mRNA in the kidney of mice exposed to Cd for 6 or 12 months were significantly lower than those in the control group. These results demonstrate that Cd exerts its cytotoxicity through the suppression in SLC2A4 expression and the subsequent inhibition of MEF2A transcriptional activity. Cd‐induced suppression of SLC2A4 expression also reduces cellular ATP levels, partly by reducing glucose levels. This study suggests that the glucose transporter plays an important role in the renal toxicity of Cd, and provides a crucial breakthrough in our understanding of the mechanism of Cd toxicity. [ABSTRACT FROM AUTHOR]

Hypothesized model of the inhibitory effect of Cd on Fe transport. • Cadmium decreases serum iron concentrations in mice. • Cadmium inhibits the expression of iron transport-related genes in the mouse duodenum. • Cadmium decreases duodenum levels of divalent metal transporter 1 and ferroportin 1. • Cadmium decreases the expression of iron transport-related factors in Caco-2 cells. Cadmium (Cd) is an environmental contaminant that triggers toxic effects in various tissues such as the kidney, liver, and lung. Cd can also cause abnormal iron metabolism, leading to anemia. Iron homeostasis is regulated by intestinal absorption. However, whether Cd affects the iron absorption pathway is unclear. We aimed to elucidate the relationship between the intestinal iron transporter system and Cd-induced iron deficiency anemia. C57BL/6J female and male mice, 129/Sv female mice, and DBA/2 female mice were given a single oral dose of CdCl 2 by gavage. After 3 or 24 h, Cd decreased serum iron concentrations and inhibited the expression of iron transport-related genes in the duodenum. In particular, Cd decreased the levels of divalent metal transporter 1 and ferroportin 1 in the duodenum. In addition, human colon carcinoma Caco-2 cells were treated with CdCl 2. After 72 h, Cd decreased the expression of iron transport-related factors in Caco-2 cells with a pattern similar to that seen in the murine duodenum. These findings suggest that Cd inhibits iron absorption through direct suppression of iron transport in duodenal enterocytes and contributes to abnormal iron metabolism. [ABSTRACT FROM AUTHOR]

We introduce amphiphilic nanoplatelets (ANPLs) that not only have a nanoscale Janus platelet geometry, but can also induce complementary face-to-face interactions among Pickering emulsion droplets. We showed that the ANPLs with such high surface activity can be a promising colloid surfactant enabling smart rheology modification of complex emulsion fluids. [ABSTRACT FROM AUTHOR]

• RT increased the risk of ischemic CVD by 40.8% in the entire HNC cohortand by 44.3% in the PSM cohort. • The risk of ischemic CVD by RT was adjusted for other clinical risk factors. • The ischemic CVD risk by RT was lower than the risk by hypertension or diabetes. • Regular follow up and appropriate screening for CVD are required for HNC patients after RT. Several reports suggested that radiotherapy (RT) was related to an increased risk of cerebrovascular disease (CVD) in head and neck cancer (HNC) patients, but other risk factors of CVD were not properly considered in estimating the risk of RT. The purpose of this study is to analyze the effect of RT on the risk of CVD in HNC patients. The Korean Central Cancer Registry data and Korean National Health Insurance Service data were used. A total of 5570 patients with newly diagnosed HNC between the years 2003–2005 was included in our study cohort. We analyzed the effect of treatment modality and other socioeconomic variables on ischemic CVD incidence using the Cox proportional hazard regression model both in the entire cohort (n = 5570) and in the propensity score matching (PSM) cohort (n = 3310). RT increased the CVD risk by 40.8% (aHR: 1.408, p = 0.006) in the entire cohort and by 44.3% (aHR: 1.443, p = 0.047) in the PSM cohort, respectively. The risk of ischemic CVD increased by RT after adjusting for other socioeconomic and clinical risk factors. Regular follow up and appropriate screening for CVD are required for HNC patients who received RT, and focus should be on advanced-age patients with a low socioeconomic status and known clinical risk factors of CVD. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the optimal entomopathogenic fungus for the simultaneous control of the adults of two mosquito species, Aedes albopictus and Culex pipiens. The pathogenicity and virulence against the two species of mosquitoes were evaluated by using 30 isolates of Beauveria bassiana, an entomopathogenic fungus isolated from Korea that has high thermotolerance and UV-B tolerance. Regarding pathogenicity, 23 isolates were pathogenic to Ae. albopictus and 12 isolates were pathogenic to Cx. pipiens; Ae. albopictus adults were more susceptible to B. bassiana than Cx. pipiens adults. Among the isolates, 6 isolates that were simultaneously pathogenic to the two species of mosquitoes were used to evaluate virulence and conidia productivity. B. bassiana CN6T1W2 and JN5R1W1 had higher virulence than the other isolates, and they were more virulent in Ae. albopictus than inCx. pipiens. The conidia productivity of B. bassiana JN5R1W1 on millet grain medium was higher than that of B. bassiana CN6T1W2. Based on these results, B. bassiana JN5R1W1 was selected as the most efficient isolate for the simultaneous control of the two mosquito species. B. bassiana JN5R1W1 can be used effectively in the development of fungal insecticides to simultaneously control Ae. albopictus and Cx. pipiens adults with similar distribution areas. [ABSTRACT FROM AUTHOR]

The structures and properties of high capacity conversion electrodes are key factors as these undergo successive lithium insertion and conversion during an electrochemical process in the rechargeable lithium-ion batteries. The invention of alloying, conversion and displacement reactions seem to be crucial for reversible intercalation/de-intercalation of more than one Li during the metal redox oxidation state to achieve the high capacity with the electrode of modern lithium-ion batteries. Therefore, the exploration of new electrode materials is necessary based on the conversion or displacement concept and their potential applications. In addition, most of the electrode materials were selected on the basis of not only capacity, voltage and volume change of bulk, but it is also important to consider point defects, surface and interface properties, nano-size effects and metal-mixtures theoretically to meet their requirements of practical applications. In this review, we overview the development of recent conversion electrodes for their better performance experimentally and theoretically with key issues, challenges and future directions in this rapidly developing field. • High capacity conversion anodes for Li-ion batteries are thoroughly reviewed. • The invention of alloying is crucial for high capacity conversion anodes. • The reversible capacity can be increased by applying nano- and hybrid-architectures. • Theoretical studies on mechanisms of the conversion reactions have been reviewed. [ABSTRACT FROM AUTHOR]

Background and Aim: Alcoholic hepatitis (AH) ranks among the most costly diseases in South Korea. However, accurate hospitalization incidence rates, mortality rates, and contributing factors have not been investigated in South Korea. This study aimed to provide the nationwide incidence of hospitalization, inhospital mortality, and readmission rates for South Korean patients with AH. Methods: Using the Korean Health Insurance Review and Assessment service database, a total of 39 800 inpatient cases from 2008 to 2012 were identified based on the International Classification of Diseases, 10th Revision diagnosis code for AH (K70.1). Standardized hospitalization incidence and mortality rates were calculated, and logistic regression analysis was performed to identify risk factors for inhospital mortality and readmission. Follow‐up data for those admitted in 2008 were collected to assess readmissions. Results: The standardized incidence rate for AH hospitalization per 105 person/year decreased from 19 in 2008 to 14 in 2012 (P = 0.001). The annual inhospital mortality rate ranged from 0.2% to 0.5%. Inhospital mortality was significantly higher in older patients (odds ratio [OR], 1.36) and those with cirrhosis (OR, 4.40). The readmission rate for patients admitted in 2008 was 34.0%. Male sex (OR, 1.21) and low economic status (OR, 2.35) were significantly associated with readmission, whereas older age (OR, 0.96), cirrhosis (OR, 0.77), and urban residency (OR, 0.68) were inversely associated with readmission. Conclusions: This study captured a 5‐year epidemiologic period in South Korea of patients with AH to reflect the real burden of AH and to provide valuable information to policy‐makers assessing public health priorities. [ABSTRACT FROM AUTHOR]

Abstract Background Previous epidemiologic studies of the natural course of urticaria mainly focused on chronic spontaneous urticaria and were conducted at hospitals. The natural course of new-onset urticaria in the general population is unknown. Methods Patients with new-onset urticaria were identified from the National Health Insurance Service–National Sample Cohort data. Patients who had at least one visit for urticaria in 2002 and 2003 were excluded and the study cohort consisted of 1,027,620 subjects with no history of urticaria. We analyzed cumulative incidences of urticaria, chronic urticaria, and chronic urticaria remission using the life table estimation method from 2004 to 2013. Their association with related factors was analyzed using the Cox proportional hazards analysis. Results From 2004 to 2013, a total of 49,129 patients with new-onset urticaria were identified. The 10-year cumulative incidence rate of urticaria for the general population was 4.9% and that of chronic urticaria among patients with new-onset urticaria was 7.8%. Remission rates of chronic urticaria were 52.6% at 1 year and 88.9% at 5 years. Age, sex, residential area, and autoimmune thyroid disease were significantly associated with urticaria or chronic urticaria, but not with chronic urticaria remission, after adjusting for covariates. Female individuals were more likely to have new-onset urticaria but less likely to develop chronic urticaria compared with male individuals. Conclusions During the 10-year follow-up period, only a small proportion of patients with new-onset urticaria developed chronic urticaria. Remission was achieved in the majority of patients with chronic urticaria regardless of demographic characteristics or accompanying thyroid disease. [ABSTRACT FROM AUTHOR]

Abstract We performed DFT calculations to investigate the role of solvent of the non-aqueous electrolytes for the oxygen reduction reaction (ORR) kinetics in Li-air batteries. The calculated results on structural, thermodynamic and vibrational properties revealed that dimethyl sulfoxide (DMSO) is the most stable solvent among DME, DMSO, and MeCN of non-aqueous electrolytes. The LiCF 3 SO 3 /DMSO electrolyte was primarily assumed to be the most favorable for ORR kinetics from the IR analysis. We calculated thermodynamic properties of the ORR reactions held during the formation of superoxide (O 2 −) ion and the sole discharge products lithium peroxide (Li 2 O 2), and lithium oxide (Li 2 O) to study the ORR kinetics of the stable salt LiCF 3 SO 3 with three solvents namely dimethoxyethane (DME), dimethyl sulfoxide (DMSO), and acetonitrile (MeCN). The thermodynamic properties of the ORR reaction signified the best role of LiCF 3 SO 3 /DMSO electrolyte compared to LiCF 3 SO 3 /DME and LiCF 3 SO 3 /MeCN both in the gas and solution (water) phases. Highlights • The role of solvent of non-aqueous electrolyte in Li-air batteries was studied theoretically. • The LiCF 3 SO 3 /DMSO electrolyte was primarily assumed to be the most favorable for ORR kinetics from the IR analysis. • The thermodynamic properties of the ORR reactions including the (O 2 −) ion and Li 2 O 2 and Li 2 O • Improved ORR kinetics was due to the key role of LiCF 3 SO 3 /DMSO electrolyte compared to LiCF 3 SO 3 /DME and LiCF 3 SO 3 /MeCN. [ABSTRACT FROM AUTHOR]

Abstract Monoclinic clinobisvanite BiVO 4 is one of the most promising photocatalyst due to its stability, low cost, narrow band gap, and suitable valence band maximum (VBM) position. The valence band maximum of about −7.10 eV at vacuum level was observed, which is well below the redox potential of water. However, the conduction band minimum, CBM of about −4.86 eV at vacuum level, which was responsible for its low efficiency. The presence of metal (Bi or V) vacancy changed the charge density and VBM of pristine BiVO 4. Our calculated results revealed that 0.04% of the intrinsic Bi or V defects enhanced p-type conductivity and hence improved photocatalytic activity than O-interstitial in pristine BiVO 4. The optical properties of both pristine and intrinsically defective BiVO 4 were calculated and analyzed with perspective of their photocatalytic properties. Conclusively, the role of Bi or V (metal) vacancies in pristine BiVO 4 was found to be significant than O interstitials in enhancing the photocatalytic properties regarding the solar water splitting. Highlights • The electronic structure of pristine and intrinsically defective BiVO4 was investigated by DFT. • The CBM of BiVO 4 was calculated to be -4.86 eV at vacuum level, which is responsible for its low efficiency. • Bi or V vacancies enhanced p-type conductivity and hence improved photocatalytic activity than O-interstitial in BiVO 4. [ABSTRACT FROM AUTHOR]

Host molecules with a cavity or scaffold with a limited space have been utilized for photodimerization of trans‐stilbene dimer with [2 + 2] cycloaddition. The degrees of freedom of the molecules inside the cavity are generally constrained. The cycloaddition reaction of trans‐stilbene dimer was investigated for variously constrained with inter‐stilbene distances and torsional angles by ab‐initio calculations at MP2/6‐31G* level of theory. In a very short inter‐stilbene distance, a new multicyclic compound (P1) was obtained, while [2 + 2] cycloaddition product (P2) was obtained from a wide range of geometries. Both inter‐stilbene distance and torsional angle play a pivotal role in determining which product (P1 or P2) could be obtained from the cycloaddition reaction of trans‐stilbene dimer. [ABSTRACT FROM AUTHOR]

Various levels of ab initio theory using various basis sets have been tested for the energy, structure, and harmonic vibrational frequencies of the water monomer. The level of the single, double, and perturbative triple excitation coupled-cluster method [CCSD(T)] using a large basis set (O:13s,8p,4d,2f/ H:8s,4p,2d) reproduced the experimental harmonic vibrational frequencies of the water monomer within the error of 0.6 cm-1. Other calculational methods seem to have inherent errors in predicting vibrational frequencies. Even with the above large basis set significant differences between symmetric and asymmetric stretching frequencies were found at various levels of calculational method including the commonly used Möller–Plesset 2nd (MP2) and 4th (MP4) order perturbation theories. The harmonic vibrational frequencies and force constants of the water dimer at various levels of ab initio theory have also been studied, and their shifts in the dimer relative to the monomer are discussed. At the Hartree–Fock (HF) level frequency shifts in the dimer relative to the monomer as well as hydrogen bonding strength in the dimer are underestimated, while at the MP2 level these are overestimated. The values at the CCSD(T) level seem to be reliable. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

At least 246 cases of coronavirus disease (COVID-19) have been linked to nightclubs in Seoul, South Korea. During the April 30-May 5 holiday, young adults from across the country who visited nightclubs in Seoul contracted COVID-19 and spread it nationally. Nightclubs were temporarily closed to limit COVID-19 spread. [ABSTRACT FROM AUTHOR]

We introduce high-performance polyaniline (PANI) nanocomposite supercapacitors based on gamma aluminum oxide (γ-Al 2 O 3 ) and gamma iron (III) oxide (γ-Fe 2 O 3 ) nanoparticles with a high specific surface area. PANI and its polymer nanocomposites are synthesized via in situ electropolymerization on gold electrodes. The structures and morphologies are characterized by cyclic voltammetry, FT-IR spectroscopy, SEM, TEM, and EDX. The electrochemical properties and specific surface area of the electrodes are investigated by galvanostatic charge–discharge, electrochemical impedance spectroscopy (EIS) and BET theory. The enhanced specific capacitance with higher surface area and conductivities is observed in PANI/γ-Fe 2 O 3 (342 F/g), PANI/γ-Al 2 O 3 (292 F/g) and PANI (180 F/g) electrodes with a constant current density of 1A/g. The cyclic performance of the PANI electrodes following 8000 cycles of operations were at 87% (PANI), 91% (PANI/γ-Al 2 O 3 ), and 93% (PANI/γ-Fe 2 O 3 ) of their initial capacitance. In addition, higher specific capacitances, higher conductivity and cyclic self-stabilities observed for the PANI/nanocomposite electrodes can provide new opportunities in the field of energy storage and supercapacitor applications. [ABSTRACT FROM AUTHOR]

We present a review of groundwater studies over the past 50 years (1968-2017) in Korea. With economic and agricultural growth, water demand has been expanding, and groundwater development is gradually increasing. Initially, groundwater studies were largely focused on using pumping and slug tests to understand aquifers in Korea. However, the interest has expanded to groundwater monitoring and data analyses, as many national and local networks for monitoring groundwater quantity and quality have been implemented. Frequent severe droughts in recent decades have led to research on the design and pilot tests for managed aquifer recharge, especially on the volcanic island of Jeju and agricultural areas. As groundwater development and its use has increased, groundwater contamination is becoming a public grievance. Thus, effective investigation of contaminated groundwater and its efficient remediation are big issues in the Research and Development (R & D) sector. The recent Gyeongju earthquake posed an additional challenge for Korean groundwater scientists to develop a method to predict earthquakes using groundwater monitoring. Furthermore, changes in precipitation patterns caused by the changing climate aggravate groundwater recharge conditions. The country has seen many academic and technical achievements in groundwater science, but many issues remain to be resolved in the near future. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy) and polypyrrole-based gamma aluminum oxide (γ-Al 2 O 3 ) and gamma iron (III) oxide (γ-Fe 2 O 3 ) nanocomposites were synthesized via in situ electropolymerization methods Films were characterized via cyclic voltammetry (CV) and in situ spectroelectrochemistry methods such as in situ UV–Visible spectroscopy and in situ conductivity measurements. Polymer nanocomposite structures and morphologies were studied and characterized via Fourier transform infrared (FT-IR) spectroscopy, electrochemical impedance spectroscopy (EIS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to the CV results of the nanocomposites, the separation of anodic and cathodic peak potential of the redox couples (ΔE) exhibited good reversibility with a positive potential shift compared with PPy during redox sweeps. The electrochemical properties of PPy, PPy/γ-Fe 2 O 3, and PPy/γ-Al 2 O 3 nanocomposite electrodes in a solution of H 2 SO 4 were studied via CV, galvanostatic charge–discharge, and EIS measurements to understand the pseudocapacitance that formed due to oxidation and reduction reactions over the double layer capacitance. Results for the nanocomposites revealed that they were very good candidates for supercapacitor applications, with higher specific capacitances, cyclic self-stabilities, and better rate capabilities than those of PPy films. The specific capacitance values of PPy/γ-Fe 2 O 3 (106 F/g) and PPy/γ-Al 2 O 3 (92 F/g) nanocomposites based on a three-electrode cell configuration from galvanostatic charge–discharge at a constant current density of 1 A/g were higher than that for PPy (75 F/g). [ABSTRACT FROM AUTHOR]

Mutations and histidine (His) tautomerism in profilin-1 (PFN1) are associated with amyotrophic lateral sclerosis (ALS). The conformational changes in PFN1 caused by the collective effects of G117V mutation and His tautomeric isomers εε, εδ, δε, and δδ were clarified using molecular dynamics (MD) simulations. The predominant structural variations were seen in α-helices, β-sheets, turns, and coils and the His tautomer's unique degree of disruption was seen in these conformations. The content of α-helices was 23.2 % in the εε and δδ isomers, but the observed α-helices in the isomers εδ and δε were 20.3 % and 21.7 % respectively. The percentage of β-sheet was found to be higher (34.1) in the εε isomer than in the εδ, δε, and δδ isomers, and the values were 30.4, 29.7, and 31.9, respectively. Intermolecular water dynamics analysis discloses that His 133 can form an intramolecular H-bond interaction (Nα-H---Nδ), confirming the experimental observations in the simulations of εε, δε, and δδ isomers of G117V PFN1 mutant. It was concluded that these solvent molecules are crucial for aggregation and must be considered in future research on the PFN1 associated with ALS. Overall, the study offers a thorough microscopic understanding of the pathogenic mechanisms behind conformational changes that cause aggregation illnesses like ALS. [ABSTRACT FROM AUTHOR]

The adsorption of sulfur dioxide (SO 2 ) on pristine and modified graphyne (including boron- or nitrogen- doping and introducing a single carbon atom defect) was investigated by density functional theory calculations. The structural, electronic, and magnetic properties of graphyne were changed according to the dopant atom site of doping and vacancy. SO 2 adsorption was obviously affected by modification of graphyne. SO 2 weakly interacted with pristine and nitrogen-doped graphynes. Boron doping at the sp-hybridized carbon site and introducing a single carbon atom vacancy in graphyne brought about a dramatic enhancement in SO 2 adsorption. The strongly chemisorbed SO 2 at these active sites caused deformation of the graphyne structure and electron redistribution, which induced changes in the conductivity and magnetism of graphynes. [ABSTRACT FROM AUTHOR]

Rubber nanocomposites based on carbon nanotubes (CNT), graphitic nanofiller (GR), and their hybrid (CNT+GR) were studied under static and cyclic strain for robotics applications. Room temperature vulcanized (RTV) silicone rubber was used as a matrix for the nanocomposites, which were prepared by solution mixing. The specimens based on CNT show a better modulus of 1.77 MPa than GR (0.71 MPa) and CNT+GR hybrid (0.85 MPa) specimens. The resistance was 0.27 kΩ (CNT) and 30.48 kΩ (CNT+GR hybrid) at 10% strain and increased to 0.35 kΩ and 46.49 kΩ at 100% strain. During cyclic strain (30%) tests, the CNT-based specimen shows larger hysteresis losses (slope m = -0.179) as dissipated heat than the GR (m = −0.032) and CNT+GR hybrid (m = -0.096) specimens. The specimens were tested as electrode materials in an actuator, and higher displacements of 1.992 mm (CNT), 1.489 mm (CNT+GR hybrid), and 0.075 mm (GR) were achieved at 10 kV (3 phr). Such improvements could be useful in intelligent objects as artificial muscles or electro-active locomotive parts. [ABSTRACT FROM AUTHOR]

Background: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening diseases; however, it is hard to estimate their incidence due to the rarity of these diseases. We evaluated the incidence of SJS and TEN using a nationwide administrative database. Methods: We used a national medical insurance review system (Health Insurance Review and Assessment) database which contained the claim data of the entire nation from 2009 to 2013 to estimate the accurate incidence of SJS and TEN in Korea. The diagnostic codes of L511 (SJS) or L512 (TEN) from the International Classification of Diseases-10th revision were used to define the target study population. We also retrospectively followed up a 2011 SJS and TEN cohort for 24 months in order to assess the in-hospital mortality, related complications and total claims cost due to SJS and TEN. Results: A total of 1,167 (938 SJS and 229 TEN) cases were newly diagnosed from 2010 to 2013. The age- and sex-standardized annual incidences estimated in this study were 3.96 to 5.03 in SJS and 0.94 to 1.45 in TEN per million. There was no significant change in annual incidence throughout the study periods. When analyzed by 10-year age groups, the annual incidence was the lowest in group 20–29 years and the highest in group 70 for both SJS and TEN. Based on the 2011 cohort analysis, the in-hospital mortality were 5.7 and 15.1% for SJS and TEN, respectively. The mortality increased with age, particularly, after 40 years of age. Among the complications related with SJS or TEN, ocular sequelae was the most common (43.1 and 43.4% of SJS and TEN patients, respectively) followed by urethral sequelae (5.7 and 9.4% of SJS and TEN patients, respectively). Conclusion: Overall, our data suggest that SJS, and TEN are infrequent but constantly arise throughout the years. [ABSTRACT FROM AUTHOR]

This study aimed to identify the factors influencing South Korean voters’ attitudes towards increasing public expenditure on health and to identify whether the issue of healthcare expenditure influenced candidate choice in the 2012 Korean presidential election. The study used the data from a survey conducted by the Institute of Korean Politics at Seoul National University immediately following the 2012 presidential election. The survey was completed by a nationwide sample of 1,200 people aged 19 or over using a face-to-face interview method and proportional quota sampling based on sex, age, and region. About 44.3% of respondents had a positive attitude toward increasing public health expenditure. There was no significant difference by the candidate they supported (conservative Park Geun-hye or liberal Moon Jae-in). In particular, even 44.9% of conservative supporters agreed with more spending. Politically neutral respondents (OR = 1.76, 90% CI 1.22–2.54) and strong conservative party supporters (OR = 1.53, 90% CI 1.05–2.25) were more likely to support public health expenditure increase compared to strong liberal party supporters. Also, respondents who believed that the economic gap in the country was widening were 1.91 times more likely to support an increase in public health expenditures. However, the issue of health expenditure had no influence on voters’ choice of presidential candidates, and in particular no negative effect of choice of the ruling (conservative) party’s candidate. Our results should be interpreted with care; one possible reason for this lack of effect might be that constituents voted along partisan lines regardless of their attitude to the welfare issue; another possible explanation might be the success of the “left click strategy” of the conservative party. That is, the conservatives did not reject economic democratization or social welfare expansion. Further research should be done to explain why attitudes to health spending did not directly affect choice of candidate. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to identify private clinics that have a potential to perform the role of primary care providers (PCPs) in a primary care setting in Korea where private specialists are dominant. Methods: The 2013 National Patient Sample claim data of Health Insurance Review and Assessment Service in Korea was used. Two-step cluster analysis was performed using characteristics of private clinics, and patient and utilization characteristics of 27,797 private clinics. External validation of clusters was performed by assessing the association among clusters and outcomes of care provided by private clinics. Stability of clusters was cross-validated using discriminant analysis. Results: The result classified more than a half of private clinics into a potential PCP cluster. These were private clinics with specialties considered to be those of primary care physicians and were more likely to be located in non-metropolitan areas than specialized PCPs were. Compared to specialized PCPs, they had a higher percentage of pediatric and geriatric patients, patients with greater disease severity, a higher percentage of patients with complex comorbidities or with simple or minor disease groups, a higher number of patients and visits, and the same or higher quality of primary care. The most important factor in explaining variations between PCP clusters was the number of simple or minor disease groups per patient. Conclusion: This study identified potential PCPs and suggested the identifying criteria for PCPs. It will provide useful information for formulation of a primary care strengthening policy to policy makers in Korea as well as other countries with similar specialist-dominant primary care settings. [ABSTRACT FROM AUTHOR]

Soil temperatures, water temperatures, and weather parameters were monitored at a variety of locations in the vicinity of King Sejong station, King George Island, Antarctica, during summer 2010-2011. Thermal characteristics of soil and water were analysed using time-series analyses, apparent thermal diffusivity (ATD), and active layer thickness. The temperatures of pond water and nearby seawater showed the distinctive diurnal variations and correlated strongly with solar radiation (r = 0.411-0.797). Soil temperature (0.1-0.3 m depth) also showed diurnal fluctuations that decreased with depth and were directly linked to air temperature (r = 0.513-0.783) rather than to solar radiation; correlation decreased with depth and the time lag in the response increased by 2-3 hours per 0.1 m of soil depth. Owing to the lack of snow cover, summertime soil temperature was not decoupled from air temperature. Estimated ATD was between 0.022 and 29.209 mm2/sec, showed temporal and spatial variations, and correlated strongly with soil moisture content. The maximum estimated active layer thickness in the study area was a 41-70 cm, which is consistent with values reported in the previous work. [ABSTRACT FROM AUTHOR]

We present an overview of the current status of unconventional energy development, particularly of shale gas, and underground CO storage as a measure to mitigate greenhouse gas increase in the atmosphere. We review their potential to induce seismicity, which has caused debates among related energy enterprises, engineers, researchers, and environmental and public communities regarding their potential hazards. Studies show that fracking can be a problem in that it consumes abundant water, but the seismicity induced by fracking has not yet been observed to induce many felt earthquakes. However, massive wastewater injection, a part of the unconventional energy development process has caused M5.0+ earthquakes in the past as well as several recent and ongoing cases of induced seismicity. Large-scale CO injection as a part of carbon sequestration efforts in the near future has a high risk of inducing large earthquakes. Therefore, injection operations related to both unconventional energy development and carbon sequestration should be optimized and managed to mitigate the likelihood of an induced seismic event. [ABSTRACT FROM AUTHOR]

We previously reported that some of the substrate proteins recognized by Hrt3 or Ucc1, a component of Skp1/Cdc53/F-box protein ubiquitin ligase, may include proteins that are involved in the methylmercury toxicity and degraded by the proteasome. In this study, we found that Dld3 and Grs1 bound to Hrt3 and that Eno2 bound to Ucc1 using a yeast two-hybrid screening. We demonstrated that Dld3 and Grs1 are substrates that are ubiquitinated by Hrt3, and Eno2 is a substrate that is ubiquitinated by Ucc1. Moreover, any yeast showing overexpression of Dld3, Grs1, and Eno2 demonstrated higher methylmercury sensitivity. This indicates that Hrt3 and Ucc1 are involved in alleviating the methylmercury toxicity by promoting proteasomal degradation through the ubiquitination of Dld3, Grs1, and Eno2. [ABSTRACT FROM AUTHOR]

There is limited quantitative evidence to investigate short-term suicide rates although the risk of suicide in psychiatric patients is exceptionally high in the early post-discharge period. This study aimed to explore the trends of the 30 days suicide rate after discharge using population-based data from Korea. This study was conducted on psychiatric patients aged 15 years or older discharged between 2010 and 2018. Patients were extracted from the National Health Insurance Claim Database (NHICD) and information on suicide was obtained from the National Statistical Office. Age-standardized suicide rate (ASR) and Standardized Mortality Ratio (SMR) within 30 days after discharge was estimated and tested using joinpoint regression. Of the 1,576,028 patients discharged from hospitals from 2010 to 2018, 53.9 % were male and 47.9 % were aged between 40 and 59 years. The 30 days ASRs for psychiatric patients after discharge varied from 174.9 to 218.0 per 100,000 patients with no clear trend excluding patients with schizophrenia and anxiety disorder. The SMR for suicide within 30 days after discharge was 66.8 in 2016–2018, and patients aged 20 to 39, female, and patients with depression had high SMRs compared to other groups. Factors that may impact the suicide were not considered in this study. Since the NHICD data is collected for payment of medical expenses, there may be scope for inaccuracies. The 30 days suicide rate after psychiatric discharge has failed to decrease between 2010 and 2018. This study recommends early interventions after discharge and intensive interventions for patient groups who may be vulnerable to suicide. • The annual age-standardized suicide rates varied from 174.9 to 218.0 per 100,000 patients and there were no significant decrease between 2010 and 2018 in Korea • The standardized mortality ratio for suicide indicated a steady decline over time. • Patients aged 20 to 59, female, and patients with depression had high standardized mortality ratios compared to other groups. [ABSTRACT FROM AUTHOR]

Research on soil microplastics is currently at an early stage, and there is no widely approved sampling protocol. Even so, any basic research should minimize errors to ensure that they are not amplified in future research. This paper examines some weaknesses of the original research paper 'Soil microplastic pollution under different land uses in tropics, southwestern China' recently published in this journal. The authors neglected to report the equipment used for soil sampling and did not use field blank samples. There is also a soil layer that was incorrectly named. The type and pore size of filter paper used for filtration during pre-analytical soil sample preparation is very important. In this paper the nature of the filter paper used, and its larger pore sizes are questionable by today's scientists. In addition, the authors in the original paper also overlooked reporting the statistical package used for statical analysis and ensuring if all data sets obey normality, homogeneity, and equality before running the one-way ANOVA test. This statistical step is widely considered mandatory, especially in the soil science community. So, this makes it difficult to trust the results documented. Furthermore, in the original paper, the needle and stereo microscope instruments used to sort microplastic-like materials prior to proper analysis are not reliable. [Display omitted] • A dissecting needle and stereo microscope shouldn't be used to sort out soil microplastics. • Gold-coated filter paper with smaller pore size is better than nitrocellulose filter paper. • The 0–10cm is the top soil layer and 10–20cm is the subsoil layer not a deep soil layer. • The statistical package used for analysis must be documented accordingly. • If the dataset is a normal distribution prior to ANOVA testing, it must be confirmed and reported. [ABSTRACT FROM AUTHOR]

We examined groundwater and stream water interaction in the Inbuk stream, Korea, using various approaches including hydrologic, thermal, hydrochemical, and isotopic methods. For this purpose, we installed four piezometers (IYHW1-4) in the streambed at 10 m interval across the stream and at depths of 0.90 to 1.54 m. We monitored water levels and water temperatures every hour using automatic transducers at the piezometers and in the stream (IYSW1) from September 2013 to April 2014. We also analyzed chemical and isotopic compositions for the hyporheic waters, stream water, and nearby groundwater in early September and late November in 2013. The water levels and hydraulic gradients revealed that three (IYHW1, 2, and 4) of the piezometers were in upwelling conditions for most of the monitoring period, except for the earliest short period (considered to be the wet season), whereas one piezometer (IYHW3) showed a reverse behavior, indicating that the gaining was dominant in the dry period. The mean calculated influx to the stream was 3.04 × 10 cm/sec. Observed temperatures of stream water, hyporheic waters, and groundwater also revealed that stream water was downwelling in the early monitoring period (wet season), whereas the groundwater was generally upwelling in most of the resting period, which is consistent with the water level interpretation. Chemical composition analysis indicated that most of the waters were Ca-HCO type for both seasons. However, no distinctive difference between chemical compositions of water without substantial seasonal variation negated any inference on the flow conditions. The mixing ratios computed from oxygen and hydrogen isotopic compositions indicated that losing conditions were dominant in the wet season, whereas gaining conditions prevailed in the dry season. The interpretations of stream water and groundwater interactions based on these different methods are relatively consistent for this study area, indicating that such combined methods will be very useful in enhancing understanding of groundwater and stream water interaction. [ABSTRACT FROM AUTHOR]

Low bandgap conjugated copolymers composed of thiophene-capped diketopyrrolopyrrole and benzene with/without fluorination were synthesized to investigate the effect of fluorine substitution on their photovoltaic properties. With increasing the number of substituted fluorine atom on benzene, both HOMO and LUMO energy levels of the copolymer are lowered and its crystallinity is increased. The fibril size of copolymer:PC 71 BM blend becomes smaller as the number of substituted fluorine increases. As a result, the copolymer with two fluorine substitution exhibits deeper HOMO energy level (−5.30 eV), leading to higher V OC (0.72 V), and also enhanced crystallinity (polymer chain packing), leading to higher J SC (12.4 mA cm −2 ) as compared to mono- and non-fluorinated ones. The copolymer with two fluorine atoms shows a promising power conversion efficiency of 5.63%. [ABSTRACT FROM AUTHOR]

We constructed α-graphyne nanotubes (αGyNTs) and performed density functional theory calculations to investigate the electronic properties of zigzag and armchair αGyNTs. We found that all zigzag graphyne nanotubes (Z-αGyNTs) were semiconductors. In particular, the band gap of Z-αGyNTs showed an oscillatory dependence on tube size which could be further classified into three families with N z = 3 m − 1, 3 m and 3 m + 1 where m is a positive integer. This resulted in band gap magnitudes in the following rank order: 3 m − 1 > 3 m + 1 > 3 m. Armchair αGyNTs were also calculated to be semiconductor with very small band gaps when tube size is small, though they become metallic as the tube size increases. [ABSTRACT FROM AUTHOR]

In this study, we investigated a series of metal-free benzotriazole-based organic dyes. The geometries, electronic properties, light harvesting efficiency, and electronic absorption spectra of these dyes were studied using the density functional theory and time-dependent density functional theory. The optimised geometries indicate that these dyes are non-planar and thereby effectively inhibit close intermolecular π–π aggregation. The band gap of these dyes ensures a positive effect on the process of electron injection and dye regeneration. The band gap trend corroborates well with the predicted spectra data. Our theoretical calculations reveal that the designed metal-free organic dyes can be used as potential sensitisers for solar cells compared to the best known organic sensitiser (Y123) to date. [ABSTRACT FROM AUTHOR]

The article presents a case study of milium-like syringoma (MLS) limited to the neck in a 30-year-old Korean woman with papules on her anterior benign tumour. The patient under histopathology, showing a syringoma with a cyst that consists of laminated keratinous materials. It mentions the role of race or ethnicity in the pathogenesis of the lesions.

Highlights: [•] The interaction strength of the C–X…π complex can be tuned by up to ∼2.35kcal/mol through substituents. [•] The introduction of electron-donating groups on benzene increased the interaction energy. [•] Whereas electron-withdrawing groups give the opposite effect. [ABSTRACT FROM AUTHOR]

With a growing demand for fresh water, mainly due to the rapidly developing economy, their interests focus on securing plentiful groundwater resources for drinking, domestic, agricultural and industrial purposes. In addition, remediation of contaminated groundwater has become another main interest. Hence, many environmental tracers, such as CFCs, Ra, Rn, CH, δO, δD, H, He, δC, δCl, and applied tracers, such as Cl, Br and rhodamine WT, have been widely used in the country for groundwater studies with different purposes. The main purposes include estimations of submarine groundwater discharge pathways and their quantification in coastal regions, especially in Jeju (volcanic island), as well as examinations of groundwater origin and mixing with stream water, groundwater age dating, tracing (apportioning) the contamination sources of chlorinated solvents (e.g., TCE, PCE) in industrial areas, and identification of reservoir (large dam) leakage. This paper reviews the use of environmental and applied tracers in Korean groundwater studies and provides perspectives on their use. [ABSTRACT FROM AUTHOR]

We examined the alteration of gene expression in HK-2 human proximal tubular cells exposed to cadmium (Cd) using DNA microarray analysis. Cd increased the expression of 30 genes, including 7 genes coding for heat shock proteins, more than 2.0-fold and decreased the expression of 21 genes, including transcription-related genes, such as AP2B1, HOXA7, HOXA9 and TCEB2, less than 0.5-fold prior to the appearance of cytotoxicity in HK-2 cells. [ABSTRACT FROM AUTHOR]

Ube2d ubiquitin-conjugating enzymes promote p53 ubiquitination and proteasomal degradation. We previously showed that cadmium induced p53-dependent apoptosis through the suppression of expression of Ube2d family genes (Ube2d1, Ube2d2, Ube2d3 and Ube2d4) in normal rat proximal tubular cells. Here we examined the effects of inorganic arsenic and inorganic mercury, which induce apoptosis in proximal tubular cells, on cellular protein level of p53 and gene expression of Ube2d family. Inorganic arsenic induced apoptosis with p53 accumulation, and suppressed Ube2d1, Ube2d2 and Ube2d4 expression, but not Ube2d3. On the other hand, although apoptosis was induced in response to inorganic mercury in proximal tubular cells, protein level of p53 was not elevated by inorganic mercury. These results suggest that inorganic arsenic, but not inorganic mercury, may induce p53-dependent apoptotic pathways through downregulation of gene expression of Ube2d family in proximal tubular cells. [ABSTRACT FROM AUTHOR]

The chemical and isotopic compositions of groundwater and stream water in the Haean basin, Korea, which have been intensively used for agricultural irrigation, were examined. The field parameters and chemical compositions were typical of relatively uncontaminated waters, except for the agricultural impact. The low EC levels indicated that the waters had not experienced any significant geochemical processes such as water-rock interaction and evaporation. The very similar chemical compositions and ionic ratios were also indicative of fast circulation and good hydraulic connection. The oxygen and hydrogen isotopic compositions of most of the samples in wet and dry seasons showed very similar range which indicated a single source for both waters without any significant geochemical alteration. However, in the wet season, evaporation trends were observed in some groundwaters because of inflow of irrigation return flow from a rice paddy field. The isotopes of both waters were affected by the altitude and amount of precipitation. [ABSTRACT FROM AUTHOR]