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1.
Plant Mol Biol ; 114(1): 5, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38227117

RESUMO

Floral transition is accelerated by exposure to long-term cold like winter in plants, which is called as vernalization. Acceleration of floral transition by vernalization is observed in a diversity of biennial and perennial plants including Brassicaceae family plants. Scientific efforts to understand molecular mechanism underlying vernalization-mediated floral transition have been intensively focused in model plant Arabidopsis thaliana. To get a better understanding on floral transition by vernalization in radish (Raphanus sativus L.), we investigated transcriptomic changes taking place during vernalization in radish. Thousands of genes were differentially regulated along time course of vernalization compared to non-vernalization (NV) sample. Twelve major clusters of DEGs were identified based on distinctive expression profiles during vernalization. Radish FLC homologs were shown to exert an inhibition of floral transition when transformed into Arabidopsis plants. In addition, DNA region containing RY motifs located within a Raphanus sativus FLC homolog, RsFLC1 was found to be required for repression of RsFLC1 by vernalization. Transgenic plants harboring disrupted RY motifs were impaired in the enrichment of H3K27me3 on RsFLC1 chromatin, thus resulting in the delayed flowering in Arabidopsis. Taken together, we report transcriptomic profiles of radish during vernalization and demonstrate the requirement of RY motif for vernalization-mediated repression of RsFLC homologs in radish (Raphanus sativus L.).


Assuntos
Arabidopsis , Brassicaceae , Raphanus , Raphanus/genética , Arabidopsis/genética , Vernalização , Cromatina
2.
Diabetes Obes Metab ; 26(7): 2588-2597, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38618974

RESUMO

AIMS: To explore the effect of renal function on the pharmacokinetic (PK) and pharmacodynamic (PD) profile and safety of enavogliflozin, a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes mellitus (T2DM). METHODS: An open-label, two-part clinical trial was conducted in T2DM patients, stratified by renal function: Group 1, normal renal function; Group 2, mild renal impairment (RI); Group 3, moderate RI; and Group 4, severe RI. In Part A, Groups 2 and 4 received enavogliflozin 0.5 mg once. In Part B, Groups 1 and 3 received enavogliflozin 0.5 mg once daily for 7 days. Serial blood and timed urine samples were collected to analyse the PK and PD characteristics of enavogliflozin. Pearson's correlation coefficients were calculated to assess the correlations between PK or PD parameters and creatinine clearance (CrCL). RESULTS: A total of 21 patients completed the study as planned. The area under the curve (AUC) for enavogliflozin was not significantly correlated with CrCL, although the maximum concentration slightly decreased as renal function decreased. By contrast, daily urinary glucose excretion (UGE) was positively correlated with CrCL after both single- (r = 0.7866, p < 0.0001) and multiple-dose administration (r = 0.6606, p = 0.0438). CONCLUSIONS: Systemic exposure to oral enavogliflozin 0.5 mg was similar among the patients with T2DM regardless of their renal function levels. However, the glucosuric effect of enavogliflozin decreased with RI. Considering the UGE observed and approved therapeutic use of other SGLT2 inhibitors, the efficacy of enavogliflozin with regard to glycaemic control could be explored in patients with mild and moderate RI (estimated glomerular filtration rate ≥30 or ≥45 mL/min/1.73 m2) in a subsequent larger study.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Masculino , Inibidores do Transportador 2 de Sódio-Glicose/farmacocinética , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Pessoa de Meia-Idade , Feminino , Idoso , Taxa de Filtração Glomerular/efeitos dos fármacos , Glicemia/efeitos dos fármacos , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/uso terapêutico , Glucosídeos/farmacocinética , Glucosídeos/uso terapêutico , Glucosídeos/farmacologia , Glucosídeos/efeitos adversos , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/fisiopatologia , Adulto , Nefropatias Diabéticas/tratamento farmacológico , Hemoglobinas Glicadas/análise , Hemoglobinas Glicadas/efeitos dos fármacos , Hemoglobinas Glicadas/metabolismo , Insuficiência Renal/metabolismo , Transportador 2 de Glucose-Sódio , Glicosúria/induzido quimicamente , Benzofuranos
3.
Int J Mol Sci ; 24(4)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36834697

RESUMO

The threshold displacement energy (TDE) is an important measure of the extent of a material's radiation damage. In this study, we investigate the influence of hydrostatic strains on the TDE of pure tantalum (Ta) and Ta-tungsten (W) alloy with a W content ranging from 5% to 30% in 5% intervals. Ta-W alloy is commonly used in high-temperature nuclear applications. We found that the TDE decreased under tensile strain and increased under compressive strain. When Ta was alloyed with 20 at% W, the TDE increased by approximately 15 eV compared to pure Ta. The directional-strained TDE (Ed,i) appears to be more influenced by complex ⟨i j k⟩ directions rather than soft directions, and this effect is more prominent in the alloyed structure than in the pure one. Our results suggest that radiation defect formation is enhanced by tensile strain and suppressed by compressive strain, in addition to the effects of alloying.


Assuntos
Tantálio , Tungstênio , Tantálio/química , Tungstênio/química , Ligas/química
4.
Mol Biol Evol ; 38(9): 3664-3675, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-33964159

RESUMO

Limited genome resources are a bottleneck in the study of horizontal transfer (HT) of DNA in plants. To solve this issue, we tested the usefulness of low-depth sequencing data generated from 19 previously uncharacterized panicoid grasses for HT investigation. We initially searched for horizontally transferred LTR-retrotransposons by comparing the 19 sample sequences to 115 angiosperm genome sequences. Frequent HTs of LTR-retrotransposons were identified solely between panicoids and rice (Oryza sativa). We consequently focused on additional Oryza species and conducted a nontargeted investigation of HT involving the panicoid genus Echinochloa, which showed the most HTs in the first set of analyses. The comparison of nine Echinochloa samples and ten Oryza species identified recurrent HTs of diverse transposable element (TE) types at different points in Oryza history, but no confirmed cases of HT for sequences other than TEs. One case of HT was observed from one Echinochloa species into one Oryza species with overlapping geographic distributions. Variation among species and data sets highlights difficulties in identifying all HT, but our investigations showed that sample sequence analyses can reveal the importance of HT for the diversification of the TE repertoire of plants.


Assuntos
Elementos de DNA Transponíveis , Oryza , Elementos de DNA Transponíveis/genética , Evolução Molecular , Transferência Genética Horizontal , Oryza/genética , Poaceae/genética , Análise de Sequência
5.
Proc Natl Acad Sci U S A ; 116(10): 4416-4425, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30787193

RESUMO

A fundamental tenet of multicellular eukaryotic evolution is that vertical inheritance is paramount, with natural selection acting on genetic variants transferred from parents to offspring. This lineal process means that an organism's adaptive potential can be restricted by its evolutionary history, the amount of standing genetic variation, and its mutation rate. Lateral gene transfer (LGT) theoretically provides a mechanism to bypass many of these limitations, but the evolutionary importance and frequency of this process in multicellular eukaryotes, such as plants, remains debated. We address this issue by assembling a chromosome-level genome for the grass Alloteropsis semialata, a species surmised to exhibit two LGTs, and screen it for other grass-to-grass LGTs using genomic data from 146 other grass species. Through stringent phylogenomic analyses, we discovered 57 additional LGTs in the A. semialata nuclear genome, involving at least nine different donor species. The LGTs are clustered in 23 laterally acquired genomic fragments that are up to 170 kb long and have accumulated during the diversification of Alloteropsis. The majority of the 59 LGTs in A. semialata are expressed, and we show that they have added functions to the recipient genome. Functional LGTs were further detected in the genomes of five other grass species, demonstrating that this process is likely widespread in this globally important group of plants. LGT therefore appears to represent a potent evolutionary force capable of spreading functional genes among distantly related grass species.


Assuntos
DNA de Plantas/genética , Transferência Genética Horizontal , Genes de Plantas , Poaceae/genética , Cromossomos de Plantas , Filogenia , Poaceae/classificação
6.
Int J Mol Sci ; 23(18)2022 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-36142775

RESUMO

Owing to the emergence and improvement of high-throughput technology and the associated reduction in costs, next-generation sequencing (NGS) technology has made large-scale sampling and sequencing possible. With the large volume of data produced, the processing and downstream analysis of data are important for ensuring meaningful results and interpretation. Problems in data analysis may be encountered if researchers have little experience in using programming languages, especially if they are clinicians and beginners in the field. A strategy for solving this problem involves ensuring easy access to commercial software and tools. Here, we observed the current status of free web-based tools for microbiome analysis that can help users analyze and handle microbiome data effortlessly. We limited our search to freely available web-based tools and identified MicrobiomeAnalyst, Mian, gcMeta, VAMPS, and Microbiome Toolbox. We also highlighted the various analyses that each web tool offers, how users can analyze their data using each web tool, and noted some of their limitations. From the abovementioned list, gcMeta, VAMPS, and Microbiome Toolbox had several issues that made the analysis more difficult. Over time, as more data are generated and accessed, more users will analyze microbiome data. Thus, the availability of free and easily accessible web tools can enable the easy use and analysis of microbiome data, especially for those users with less experience in using command-line interfaces.


Assuntos
Microbioma Gastrointestinal , Microbiota , Microbioma Gastrointestinal/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Microbiota/genética , RNA Ribossômico 16S/genética , Software
7.
Environ Monit Assess ; 194(10): 754, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36083375

RESUMO

Organochlorine pesticides (OCPs) are widely used in certain countries. We determined atmospheric concentrations, distribution patterns, and seasonal variations of OCPs at four sites in South Korea for 1 year. Samples of 22 OCPs were collected using a high-volume air sampler, and measured via the isotope dilution method with HRGC/HRMS. In South Korea, pentachlorobenzene (PeCB), hexachlorocyclohexane (HCB), and endosulfan (EnSF) were dominant, accounting for > 87% of total OCPs. Spatial distributions showed significant differences and the highest levels were observed in Seosan (295.2 pg·m-3), indicating the compounding potential of diverse sources as Seosan has concentrated large-scale industrial complexes and agricultural activity (Seoul: 243.6 pg·m-3 > Jeju: 193.5 pg·m-3 > Baengnyeong: 178.2 pg·m-3). The isomeric ratios of OCPs in the South Korean atmosphere indicated that the dominant sources of HCB and dichlorodiphenyltrichloroethane were primarily used in the past; meanwhile, chlordane (CHL) and EnSFs were derived from recent material inputs. Seasonally, OCP concentrations largely peaked in summer with minimum values in winter. This apparent temperature dependence suggests the re-volatilization of accumulated chemicals into the atmosphere. Additionally, an air mass back trajectory indicated the influence of pollutants released from a reservoir through long-range atmospheric transport in the summer. In particular, restricted OCPs are primarily released into the atmosphere by inadvertent sources, such as industrial activities and volatilization from contaminated areas. Thus, severe OCP pollution in Korea is due to the mobile nature of the particles. These data can be useful for the continuous monitoring of long-range transported air pollutants that are transferred between countries.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Clorados , Praguicidas , Poluentes Atmosféricos/análise , Atmosfera/química , Monitoramento Ambiental , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Estações do Ano
8.
Plant J ; 104(3): 581-595, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32748440

RESUMO

Similar progressive leaf lesion phenotypes, named conring for "concentric ring," were identified in 10 independently derived maize lines. Complementation and mapping experiments indicated that the phenotype had the same genetic basis in each line - a single recessive gene located in a 1.1-Mb region on chromosome 2. Among the 15 predicted genes in this interval, Zm00001d003866 (subsequently renamed Conring or Cnr) had insertions of four related 138 bp transposable element (TE) sequences at precisely the same site in exon 4 in nine of the 10 cnr alleles. The 10th cnr allele had a distinct insertion of 226 bp of in exon 3. Genetic evidence suggested that the 10 cnr alleles were independently derived, and arose during the derivation of each line. The four TEs, named COINa (for COnring INsertion) through COINd, have not been previously characterized and consist entirely of imperfect 69-bp terminal inverted repeats characteristic of the Foldback class of TEs. They belong to three clades of a family of maize TEs comprising hundreds of sequences in the genome of the B73 maize line. COIN elements preferentially insert at TNA sequences with a preference for C and G nucleotides in the immediately flanking 5' and 3' regions, respectively. They produce a three-base target site duplication and do not have homology to other characterized TEs. We propose that Cnr is an unstable gene that is mutated insertionally at high frequency, most commonly due to COIN element insertions at a specific site in the gene.


Assuntos
Elementos de DNA Transponíveis/genética , Zea mays/genética , Morte Celular/genética , Genoma de Planta/genética , Sequências Repetidas Terminais/genética
9.
Int J Mol Sci ; 22(19)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34638784

RESUMO

While horizontally transferred transposable elements (TEs) have been reported in several groups of plants, their importance for genome evolution remains poorly understood. To understand how horizontally transferred TEs contribute to plant genome evolution, we investigated the composition and activity of horizontally transferred TEs in the genomes of four Vitis species. A total of 35 horizontal transfer (HT) events were identified between the four Vitis species and 21 other plant species belonging to 14 different families. We determined the donor and recipient species for 28 of these HTs, with the Vitis species being recipients of 15 of them. As a result of HTs, 8-10 LTR retrotransposon clusters were newly formed in the genomes of the four Vitis species. The activities of the horizontally acquired LTR retrotransposons differed among Vitis species, showing that the consequences of HTs vary during the diversification of the recipient lineage. Our study provides the first evidence that the HT of TEs contributes to the diversification of plant genomes by generating additional TE subfamilies and causing their differential proliferation in host genomes.


Assuntos
Transferência Genética Horizontal , Variação Genética , Genoma de Planta , Retroelementos , Vitis/genética
10.
Opt Express ; 27(20): 29178-29195, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31684656

RESUMO

We herein propose a multiwalled carbon nanotube (MWCNT) doping method into liquid crystal (LC) alignment polyimides (PIs) with low resistivity for resolving both issues of voltage holding and image sticking in low-frequency-driven fringe-field switching (FFS) LC modes using negative dielectric LCs (n-LCs). By utilizing strong ion trapping ability of MWCNTs, the FFS n-LC cell aligned by low resistivity PIs with 0.05 wt% MWCNT doping exhibited an excellent voltage holding ratio of 99% under an extremely low operation frequency of 0.5 Hz and approximately 23.6 times better surface discharging property than that aligned by high resistivity PIs.

11.
Part Fibre Toxicol ; 16(1): 31, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31319864

RESUMO

BACKGROUND: Titanium dioxide (TiO2) nanoparticles are among the most manufactured nanomaterials in the industry, and are used in food products, toothpastes, cosmetics and paints. Pregnant women as well as their conceptuses may be exposed to TiO2 nanoparticles; however, the potential effects of these nanoparticles during pregnancy are controversial, and their internal distribution has not been investigated. Therefore, in this study, we investigated the potential effects of oral exposure to TiO2 nanoparticles and their distribution during pregnancy. TiO2 nanoparticles were orally administered to pregnant Sprague-Dawley rats (12 females per group) from gestation days (GDs) 6 to 19 at dosage levels of 0, 100, 300 and 1000 mg/kg/day, and then cesarean sections were conducted on GD 20. RESULTS: In the maternal and embryo-fetal examinations, there were no marked toxicities in terms of general clinical signs, body weight, food consumption, organ weights, macroscopic findings, cesarean section parameters and fetal morphological examinations. In the distribution analysis, titanium contents were increased in the maternal liver, maternal brain and placenta after exposure to high doses of TiO2 nanoparticles. CONCLUSION: Oral exposure to TiO2 during pregnancy increased the titanium concentrations in the maternal liver, maternal brain and placenta, but these levels did not induce marked toxicities in maternal animals or affect embryo-fetal development. These results could be used to evaluate the human risk assessment of TiO2 nanoparticle oral exposure during pregnancy, and additional comprehensive toxicity studies are deemed necessary considering the possibility of complex exposure scenarios and the various sizes of TiO2 nanoparticles.


Assuntos
Encéfalo/metabolismo , Fígado/metabolismo , Nanopartículas/análise , Placenta/metabolismo , Titânio/farmacocinética , Administração Oral , Animais , Relação Dose-Resposta a Droga , Feminino , Exposição Materna , Nanopartículas/química , Especificidade de Órgãos , Gravidez , Ratos , Distribuição Tecidual , Titânio/química
12.
Appl Opt ; 58(23): 6251-6256, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31503768

RESUMO

We experimentally demonstrate an all-fiber high-power fiber amplifier with high beam quality and a slope efficiency of 81.8%, using a fiber-Bragg-grating-stabilized laser diode as a narrow spectral linewidth (0.08 nm) seed source. During amplification, the spectral linewidth of the laser output is broadened from 0.08 to 0.24 nm due to nonlinear phenomena. To the best of our knowledge, we report the first experimental observation of the suppression of stimulated Brillouin scattering (SBS), with increased output power. In addition, we investigated the SBS suppression by simultaneously measuring the optical backscattered power, backscattered spectrum, and output spectrum at different values of output power. The beam quality, M2, was measured to be ∼1.28 at the maximum output power of 2.05 kW, and modal instability was not observed.

13.
Dermatol Surg ; 45(2): 203-209, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30286001

RESUMO

BACKGROUND: Minimally invasive aesthetic procedures of the neck are becoming more popular. However, anatomical studies on the venous structures of the neck in relation to these procedures are lacking. OBJECTIVE: The aims of this study were to identify the locations and communication patterns of the anterior jugular vein and external jugular vein (AJV and EJV) and the communicating vein (CV) based on superficial anatomical landmarks and to determine dangerous areas for dermal filler injections into the neck. MATERIALS AND METHODS: Thirty sides of the neck from Korean adult cadavers were dissected for this study. RESULTS: Four anatomical variants were identified. In Type Ia, the CV ran along the anterior border of the sternocleidomastoid muscle (SCM) (33.4%); in Type Ib, a single vein was observed connecting the CV and the EJV at the level of laryngeal prominence (23.3%); in Type Ic, the CV proceeded separately from the medial side of the anterior border of the SCM (13.3%); and in Type II, the CV was absent while the EJV and AJV were observed (30%). CONCLUSION: Given the 4 anatomical variants identified in this study, the authors recommend exerting caution when performing dermal filler injections approximately 10, 30, and 60 mm lateral to the midsagittal line to avoid iatrogenic side effects.


Assuntos
Preenchedores Dérmicos/administração & dosagem , Pescoço/irrigação sanguínea , Veias/anatomia & histologia , Idoso , Pontos de Referência Anatômicos , Variação Anatômica , Cadáver , Feminino , Humanos , Injeções , Veias Jugulares/anatomia & histologia , Masculino , República da Coreia
14.
Ecotoxicol Environ Saf ; 182: 109457, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31349106

RESUMO

Siloxanes have been used as chemical additives in various products since the 1940s. They are known to have potentially toxic effects, to be environmentally persistent, and to be bioaccumulative. Previous studies have reported high levels of siloxanes in various environmental matrices. In this study, 6 cyclic siloxanes (D4-D9) and 13 linear siloxanes (L3-L15) in coastal sediment collected from southeastern bays adjacent to industrial zones in South Korea (Busan, Ulsan, Jinhae, and Gwangyang) were analyzed. The contamination levels and spatial distribution of siloxanes in the coastal sediment samples were investigated, with the hazard quotients (HQs) for siloxanes evaluated using Monte Carlo simulation. Across all samples, the total concentration (Σ19) of siloxanes was in the range of 11.6-3877 (mean: 305; median: 133) ng/g dry weight (dw). The highest average concentration of Σ19 siloxanes was found in Busan (mean: 580; median: 233 ng/g dw), followed by Ulsan (mean: 316; median: 209 ng/g dw), Jinhae (mean: 266; median: 125 ng/g dw), and Gwangyang (mean: 33; median: 27 ng/g dw), all of which are suggested to be affected by both industrial and domestic activities. The highest contributions were from D5 (18%) and D6 (34%), followed by D9 (7.3%) and L11 (5.8%). The HQs for siloxanes were less than 1, indicating that there was no risk to benthic organisms in the study areas; however, further monitoring of various environmental matrices is required to fully assess the potential ecological risks.


Assuntos
Baías/química , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Siloxanas/análise , Poluentes Químicos da Água/análise , Desenvolvimento Industrial , República da Coreia
15.
Environ Geochem Health ; 41(5): 1895-1907, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30673964

RESUMO

Paddy soil contamination is directly linked to human dietary exposure to toxic chemicals via crop consumption. In Korea, rice paddy fields are often located around industrial complexes, a major anthropogenic source of metals. In this study, rice paddy soils were collected from 50 sites in three industrial cities to investigate the contamination characteristics and ecological risk of metals in the soils. The cities studied and their major industries are as follows: Ulsan (petrochemical, nonferrous, automobile, and shipbuilding), Pohang (iron and steel), and Gwangyang (iron and steel, nonmetallic, and petrochemical). Thirteen metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn) were analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES). The mean concentration of Cd (1.98 mg/kg) exceeded the soil quality guideline of Canada (1.4 mg/kg), whereas concentrations of other metals were under the standards of both Korea and Canada. Generally, levels of metal concentrations decreased with increasing distance from industrial complexes. Among the three cities, Pohang showed high concentrations of Zn (142.2 mg/kg), and Ulsan and Gwangyang showed high concentrations of Cr (33.9 mg/kg) and Ba (126.4 mg/kg), respectively. These contamination patterns were influenced by the different major industries of each city, which was clearly demonstrated by the principal component analysis results. Pollution indices suggested that As, Cd, Pb, and Zn were enriched in the paddy soils via anthropogenic activities. Comprehensive potential ecological risk indices were at considerable levels for most sites, especially because of major contributions from As and Cd, which can pose potential ecological threats.


Assuntos
Arsênio/análise , Monitoramento Ambiental , Indústrias , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Cidades , Humanos , Oryza/crescimento & desenvolvimento , República da Coreia , Solo/normas
16.
Environ Monit Assess ; 191(8): 525, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363866

RESUMO

Arsenic contamination in marine environments is a serious issue because some arsenicals are very toxic, increasing the health risks associated with the consumption of marine products. This study describes the development of an improved rapid method for the quantification of arsenic species, including arsenite (AsIII), arsenate (AsV), arsenocholine (AsC), arsenobetaine (AsB), dimethylarsinic acid (DMA), and monomethyl arsonic acid (MMA), in seaweed, sediment, and seawater samples using high-performance liquid chromatography/inductively coupled plasma-mass spectrometry (HPLC/ICP-MS). ICP-MS based on dynamic reaction cells was used to eliminate spectral interference. Ammonium nitrate- and phosphate-based eluents were used as the mobile phases for HPLC analysis, leading to shorter overall retention time (6 min) and improved peak separation. Arsenicals were extracted with a 1% HNO3 solution that required no clean-up process and exhibited reasonable sensitivity and peak resolution. The optimized method was verified by applying it to hijiki seaweed certified reference material (CRM, NMIJ 7405-a) and to spiked blank samples of sediment and seawater. The proposed method measured the concentration of AsV in the CRM as 9.6 ± 0.6 µg/kg dry weight (dw), which is close to the certified concentration (10.1 ± 0.5 µg/kg dw). The recovery of the six arsenicals was 87-113% for the sediment and 99-101% for the seawater. In the analysis of real samples, AsV was the most abundant arsenical in hijiki and gulfweed, whereas AsB was dominant in other seaweed species. The two inorganic arsenicals (AsIII and AsV) and AsV were the most dominant in the sediment and seawater samples, respectively.


Assuntos
Arsenicais/análise , Cromatografia Líquida de Alta Pressão/métodos , Monitoramento Ambiental/métodos , Espectrometria de Massas/métodos , Poluentes Químicos da Água/análise , Monitoramento Ambiental/instrumentação , Sedimentos Geológicos/química , República da Coreia , Água do Mar/química , Alga Marinha/química
17.
Opt Express ; 26(16): 20281-20297, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30119340

RESUMO

We demonstrated a 2D/3D switchable mobile display using a polarization-dependent switching liquid crystalline polymeric (LCP) lens array film. In spite of short viewing distance and enough viewing window conditions provided by a small f-number lens for mobile displays, the 3D images when switched to the multi-view 3D mode showed a low crosstalk property owing to the improved lens aberration, as applying an aspherical lens curvature interface between the planar-convex LCP layer and the concave-planar isotropic polymer layer. Both 2D and 3D images were demonstrated based on a 5.5-inch quad high definition mobile display panel, where the binocular crosstalk of the 3D mode was 3.3%.

18.
Opt Express ; 25(13): 14427-14443, 2017 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-28789029

RESUMO

We demonstrate a bistable switching liquid crystal (LC) mode utilizing a topologically self-structured dual-groove surface for degenerated easy axes of LC anchoring. In our study, the effect of the bulk elastic distortion of the LC directors on the bistable anchoring surface is theoretically analyzed for balanced bistable states based on a free energy diagram. By adjusting bulk LC chirality, we developed ideally symmetric and stable bistable anchoring and switching properties, which can be driven by a low in-plane pulsed field of about 0.7 V/µm. The fabricated device has a contrast ratio of 196:1.

19.
Opt Express ; 25(24): 30503-30512, 2017 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-29221078

RESUMO

An integral imaging microscopy (IIM) system with improved depth-of-field (DoF) using a custom-designed bifocal polarization-dependent liquid-crystalline polymer micro lens array (LCP-MLA) is proposed. The implemented MLA has improved electro-optical properties such as a small focal ratio, high fill factor, low driving voltage, and fast switching speed, utilizing a well-aligned reactive mesogen on the imprinted reverse shape of the lens and a polarization switching layer. A bifocal MLA switches its focal length according to the polarization angle and acquires different DoF information of the specimen. After two elemental image arrays are captured, the depth-slices are reconstructed and combined to provide a widened DoF. The fabricated bifocal MLA consists of two identical polarization-dependent LCP-MLAs with 1.6 mm and f/16 focal ratio. Our experimental results confirmed that the proposed system improves the DoF of IIM without the need for mechanical manipulation.

20.
BMC Pediatr ; 17(1): 169, 2017 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-28720085

RESUMO

BACKGROUND: Sudden breath-holding episodes during sleep in young children are potentially related to sudden infant death syndrome and other life-threatening events. Additionally, these episodes can negatively affect child's growth and development. CASE PRESENTATION: Here, we present 3 cases of preschool children with similar paroxysmal nocturnal waking events associated with choking that had different etiologies (nocturnal frontal lobe epilepsy, nocturnal gastroesophageal reflux disease, and parasomnia, respectively). CONCLUSIONS: It is important to take into consideration the fact that breath spells during sleep can occur as a rare manifestation of parasomnia due to gastroesophageal reflux or as a symptom of nocturnal frontal lobe epilepsy. Full video electroencephalography, polysomnography, and simultaneous gastric pH monitoring should be used for the differential diagnosis of sleep-related disorders, such as breath spells, in children.


Assuntos
Suspensão da Respiração , Epilepsia do Lobo Frontal/diagnóstico , Refluxo Gastroesofágico/diagnóstico , Parassonias/diagnóstico , Pré-Escolar , Diagnóstico Diferencial , Eletroencefalografia , Epilepsia do Lobo Frontal/fisiopatologia , Monitoramento do pH Esofágico , Feminino , Refluxo Gastroesofágico/fisiopatologia , Humanos , Parassonias/fisiopatologia , Polissonografia
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