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1.
Artículo en Inglés | MEDLINE | ID: mdl-38743475

RESUMEN

Strain CJN36-1NT, a Gram-stain-positive, non-flagellated, strictly aerobic and short rod-shaped bacterium, was isolated from flowerpot soil sampled in the Jeonju region of the Republic of Korea. Based on 16S rRNA gene sequences and the resulting phylogenetic tree, the strain belonged to the genus Microbacterium. Strain CJN36-1NT contained a chromosome of 3.6 Mbp with a G+C content of 68.5 mol%. The strain grew at 10-37 °C (optimally at 28 °C), at pH 5.0-8.0 (optimally at pH 8.0), and in the presence of 0-7 % NaCl (w/v; optimally with 0 % NaCl). Digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values between strain CJN36-1NT and its closest related species, Microbacterium protaetiae DFW100M-13T, were 82.0, 81.2, and 23.2 %, respectively. We propose naming this novel species Microbacterium horticulturae sp. nov., with CJN36-1NT (=KACC 23027T=NBRC 116065T) as the type strain.


Asunto(s)
Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Microbacterium , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Microbiología del Suelo , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , República de Corea , Microbacterium/genética
2.
Sensors (Basel) ; 23(22)2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-38005666

RESUMEN

Salt, one of the most commonly consumed food additives worldwide, is produced in many countries. The chemical composition of edible salts is essential information for quality assessment and origin distinction. In this work, a simple laser-induced breakdown spectroscopy instrument was assembled with a diode-pumped solid-state laser and a miniature spectrometer. Its performances in analyzing Mg and Ca in six popular edible sea salts consumed in South Korea and classification of the products were investigated. Each salt was dissolved in water and a tiny amount of the solution was dropped and dried on the hydrophilicity-enhanced silicon wafer substrate, providing homogeneous distribution of salt crystals. Strong Mg II and Ca II emissions were chosen for both quantification and classification. Calibration curves could be constructed with limits-of-detection of 87 mg/kg for Mg and 45 mg/kg for Ca. Also, the Mg II and Ca II emission peak intensities were used in a k-nearest neighbors model providing 98.6% classification accuracy. In both quantification and classification, intensity normalization using a Na I emission line as a reference signal was effective. A concept of interclass distance was introduced, and the increase in the classification accuracy due to the intensity normalization was rationalized based on it. Our methodology will be useful for analyzing major mineral nutrients in various food materials in liquid phase or soluble in water, including salts.

3.
Rep Pract Oncol Radiother ; 28(3): 370-378, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37795400

RESUMEN

Background: Epidemiologic studies have demonstrated race as a predictor of worse oncological outcomes. To better understand the effect of race on oncological outcomes, we utilized the Surveillance, Epidemiology, and End Results (SEER) database to determine what treatment courses are provided to minority patients and how this impacts survival. Materials and methods: A retrospective review of bone and soft tissue sarcoma cases was performed using the SEER database for a minimum 5-year survival rate (SR) using Kaplan-Meier curves. Categorical variables were compared using Pearson's χ2 test and Cramer V. Kaplan-Meier curves were used to determine survival rates (SR) and Cox regression analysis was used to determine hazard ratios (HRs). Results: Races that had an increased risk of death included Native American/Alaska Native (NA/AN) [hazard ratio (HR): 1.36, 95% confidence interval (CI): 1.049-1.761, p = 0.020) and Black (HR = 1.17, 95% CI: 1.091-1.256, p < 0.001). NA/AN individuals had the lowest SR (5-year SR = 70.9%, 95% CI: 63.8-78.0%, p < 0.001). The rate of metastasis at diagnosis for each race was 13.07% - Hispanic, 10.62% - NA/AN, 12.77% - Black, 10.61% - Asian/Pacific Islander (A/PI), and 9.02% - White individuals (p < 0.001). There were increases in the rate of metastasis at diagnosis and decreases in rates of surgical excision for Hispanic and Black patients (p < 0.001). Conclusion: Race is determined to be an independent risk factor for death in NA/AN and Black patients with sarcomas of the extremities. Access to healthcare and delay in seeking treatment may contribute to higher rates of metastasis upon diagnosis for minority patients, and decreased rates of surgical excision could be associated with poor follow up and lack of resources.

4.
Rep Pract Oncol Radiother ; 28(6): 711-719, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38515824

RESUMEN

Background: The low incidence of myxofibrosarcoma (MFS) makes high power studies difficult to perform. Demographic and prognostic factors for MFS and how they differ from all extremity soft tissue sarcomas (STS) are not well understood. The purpose of this study was to characterize a large cohort of patients with MFS and evaluate epidemiologic and survival factors when compared to all STS. Materials and methods: We performed a retrospective review of the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2015 to identify 1,440 patients diagnosed with MFS and 12,324 with STS. Survival curves were creased using Kaplan-Meier, and Cox regression analyses were performed to identify hazard ratios (HRs). Results: Overall survival was greater for STS than MFS (79% vs. 67%). Patients with MFS had a higher average age at diagnosis than STS (62 vs. 56), and older age was strongly associated with decreased survivorship for MFS (HR = 7.94). A greater proportion of patients under 30 diagnosed with MFS were female when compared to STS (49.6% vs. 45.4%). The incidence of MFS and STS increased over the 15-year period, with MFS increasing at a greater rate than STS (1.25% vs. 2.59%). Survival increased for patients diagnosed after 2008 for both STS (9.4%) and MFS (13.2%). Conclusions: There are differences between patient demographics and survival factors when comparing MFS to all STS. Monitoring changes in demographic and survival trends for rare STS subtypes like MFS is important to improve diagnostic algorithms and treatment options.

5.
Analyst ; 147(14): 3193-3200, 2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-35611571

RESUMEN

Laser-induced breakdown spectroscopy (LIBS) and near-infrared (NIR) spectroscopy, enabling the measurement of raw bile directly without sample pretreatment, were cooperatively combined to enhance the discrimination of gallbladder cancer (GBC) from other diseases of gallstone and gallbladder (GB) polyp. Since elemental contents and metabolite compositions of bile vary according to the pathological conditions of pancreaticobiliary patients, the use of complementary information could be synergetic to improve disease identification accuracy. The ratios of Mg and Na peak areas (AMg/ANa) and Na and K peak areas (ANa/AK) in the LIBS spectra of GBC samples were different from those of the remaining samples. Also, the intensity ratios of main NIR peaks differed in GBC. Nonetheless, the use of only element peak area ratio or NIR peak intensity ratio was not sufficient to clearly discriminate GBC. On the other hand, when the ANa/AK values and second NIR principal component scores were combined, the discrimination of GBC from normal/gallstone/GB polyp was substantially enhanced owing to incorporation of both complementary GBC-discriminant spectroscopic signatures.


Asunto(s)
Enfermedades de la Vesícula Biliar , Neoplasias de la Vesícula Biliar , Cálculos Biliares , Pólipos , Bilis/química , Neoplasias de la Vesícula Biliar/diagnóstico , Cálculos Biliares/diagnóstico , Humanos , Análisis Espectral
6.
J Infect Chemother ; 28(1): 47-53, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34627705

RESUMEN

INTRODUCTION: Patients with aspiration pneumonia (AP) exhibit higher mortality than those with non-AP. However, data regarding predictors of short-term prognosis in patients with community-acquired AP are limited. METHODS: Patients hospitalized with community-acquired pneumonia (CAP) were retrospectively classified into aspiration pneumonia (AP) and non-AP groups. The AP patients were further divided into nonsurvivors and survivors by 30-day mortality, and various clinical variables were compared between the groups. RESULTS: Of 1249 CAP patients, 254 (20.3%) were classified into the AP group, of whom 76 patients (29.9%) died within 30 days. CURB-65, pneumonia severity index (PSI), and Infectious Diseases Society of America/American Thoracic Society criteria for severe CAP (SCAP) showed only modest prognostic performance for the prediction of 30-day mortality (c-statistics, 0.635, 0.647, and 0.681, respectively). Along with the PSI and SCAP, Eastern Cooperative Oncology Group performance status (ECOG-PS) and blood biomarkers, including, N-terminal of prohormone brain natriuretic peptide (NT-proBNP) and albumin, were independent predictors of 30-day mortality. In models based on clinical prediction rules, including CURB-65, PSI, and SCAP, the addition of ECOG-PS further improved their c-statistics compared to the clinical prediction rules alone. In the four combinations based on SCAP, ECOG-PS, and two blood biomarkers (NT-proBNP and albumin), the c-statistics further increased to reach approximately 0.8. CONCLUSIONS: CURB-65, PSI, and SCAP exhibited only modest discriminatory power in predicting the 30-day mortality of patients with community-acquired AP. The addition of performance status and blood biomarkers, including NT-proBNP and albumin, further increased prognostic performance, showing good predictive accuracy in the SCAP-based model.


Asunto(s)
Infecciones Comunitarias Adquiridas , Neumonía por Aspiración , Neumonía , Humanos , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad
7.
Opt Express ; 29(6): 9242-9251, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33820356

RESUMEN

It was reported that whispering gallery cavities designed by conformal transformation optics can support high-Q resonant modes with emission directionality. Intrinsically, these cavities have gradient index profiles implementing conformal mappings in physical space. In this paper, using the linear coordinate transformation, we propose another design scheme of whispering gallery cavities with (piecewise-) homogeneous, anisotropic index profile. We numerically show that so-designed cavities are also able to support high-Q whispering gallery modes with directional far-field emission patterns. We verify such characteristics by using a phase space representation (called the Poincaré Husimi function) of the intracavity wave function.

8.
Opt Express ; 29(10): 14736-14744, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33985189

RESUMEN

Using the transformation cavity, a gradient index cavity designed by transformation optics, we propose a hybrid resonator system to extract unidirectional narrow-beam emission from high-Q whispering gallery modes by embedding a transformation cavity inside a deformed uniform index cavity that exhibits unidirectional narrow-beam emission. For effective mode coupling between the transformation cavity and enclosing cavity, the embedded transformation cavity is designed to have bidirectional evanescent emission, which enables most of the emission from the transformation cavity to be laterally incident on the rim of the enclosing deformed cavity. Consequently, ultrahigh-Q resonances of this system can provide a sharp free-space light output, which is difficult to achieve by embedding a homogeneous disk cavity instead of the transformation cavity.

9.
Emerg Infect Dis ; 26(10): 2346-2352, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32568662

RESUMEN

We evaluated the clinical course of asymptomatic and mildly symptomatic patients with laboratory-confirmed coronavirus disease (COVID-19) admitted to community treatment centers (CTCs) for isolation in South Korea. Of 632 patients, 75 (11.9%) had symptoms at admission, 186 (29.4%) were asymptomatic at admission but developed symptoms during their stay, and 371 (58.7%) remained asymptomatic during their entire clinical course. Nineteen (3.0%) patients were transferred to hospitals, but 94.3% (573/613) of the remaining patients were discharged from CTCs upon virologic remission. The mean virologic remission period was 20.1 days (SD + 7.7 days). Nearly 20% of patients remained in the CTCs for 4 weeks after diagnosis. The virologic remission period was longer in symptomatic patients than in asymptomatic patients. In mildly symptomatic patients, the mean duration from symptom onset to virologic remission was 11.7 days (SD + 8.2 days). These data could help in planning for isolation centers and formulating self-isolation guidelines.


Asunto(s)
Infecciones Asintomáticas , Centros Comunitarios de Salud/estadística & datos numéricos , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/epidemiología , Neumonía Viral/complicaciones , Neumonía Viral/epidemiología , Adulto , Betacoronavirus , COVID-19 , Comorbilidad , Infecciones por Coronavirus/diagnóstico , Progresión de la Enfermedad , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Pandemias , Admisión del Paciente , Transferencia de Pacientes/estadística & datos numéricos , Neumonía Viral/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , República de Corea/epidemiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , SARS-CoV-2 , Factores de Tiempo , Adulto Joven
10.
Part Fibre Toxicol ; 17(1): 5, 2020 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-31992310

RESUMEN

BACKGROUND: Although biocides at low concentrations have been used to control pests, they can be more harmful than industrial chemicals as humans are directly and frequently exposed to such biocides. Benzalkonium chloride (BAC or BKC) is a non-toxic substance used to control pests. Recently, BAC has been increasingly used as a component in humidifier disinfectants in Korea, raising a serious health concern. Moreover, it poses significant health hazards to workers handling the chemical because of direct exposure. In the present study, we aimed to evaluate the respiratory toxicity of BAC due to its inhalation at exposure concentrations of 0.8 (T1 group), 4 (T2 group) and 20 (T3 group) mg/m3. RESULTS: In our previous study on the acute inhalational toxicity of BAC, bleeding from the nasal cavity was observed in all the rats after exposure to 50 mg/m3 BAC. Therefore, in this study, 20 mg/m3 was set as the highest exposure concentration, followed by 4 and 0.8 mg/m3 as the medium and low concentrations for 6 h/day and 14 days, respectively. After exposure, recovery periods of 2 and 4 weeks were provided. Additionally, alveolar lavage fluid was analyzed in males of the BAC-exposed groups at the end of exposure and 2 weeks after exposure to evaluate oxidative damage. In the T3 group exposed to BAC, deep breathing, hoarseness, and nasal discharge were observed along with a decline in feed intake and body weight, and nasal discharge was also observed in the T1 and T2 groups. ROS/RNS, IL-1ß, IL-6, and MIP-2 levels decreased in a concentration-dependent manner in the bronchoalveolar lavage fluid. Histopathological examination showed cellular changes in the nasal cavity and the lungs of the TI, T2, and T3 groups. CONCLUSIONS: As a result, it was confirmed that the target organs in the respiratory system were the nasal cavity and the lungs. The adverse effects were evaluated as reversible responses to oxidative damage. Furthermore, the no observed adverse effect level was found to be less than 0.8 mg/m3 and the lowest benchmark dose was 0.0031 mg/m3. Accordingly, the derived no-effect level of BAC was calculated as 0.000062 mg/m3.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Compuestos de Benzalconio/toxicidad , Exposición por Inhalación/efectos adversos , Pulmón/efectos de los fármacos , Cavidad Nasal/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/inmunología , Relación Dosis-Respuesta a Droga , Exposición por Inhalación/análisis , Pulmón/inmunología , Pulmón/metabolismo , Masculino , Cavidad Nasal/inmunología , Cavidad Nasal/metabolismo , Ratas , Ratas Endogámicas F344
11.
J Toxicol Pathol ; 33(4): 265-277, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33239844

RESUMEN

The use of polyhexamethylene guanidine hydrochloride (PHMG·HCl) as a humidifier disinfectant caused an outbreak of pulmonary disease, leading to the deaths of pregnant women and children in South Korea. However, limited information is available on the inhalation toxicity of PHMG·HCl. Therefore, this study aimed to characterize the subacute inhalation toxicity of PHMG·HCl by whole-body exposure in rats. F344 rats were exposed to 0 mg/m3, 1 mg/m3, 5 mg/m3, or 25 mg/m3 of PHMG·HCl for 6 h/day, 5 days/week for two weeks via whole-body inhalation. Emaciation and rale were observed in rats in the 25 mg/m3 PHMG·HCl group. Significant changes in body weight, hematology, serum chemistry and organ weight were observed in all PHMG·HCl-exposed groups. Gross lesions showed ballooning or red focus in the lungs of rats in the PHMG·HCl-exposed groups. In histopathological examination, most of histological lesions (including degeneration, atrophy, ulcer, inflammatory cell infiltration, inflammation, and fibrosis in nasal cavity, larynx, trachea, and lungs) indicated tissue damage by PHMG·HCl in all PHMG·HCl-exposed groups. Additionally, atrophy of the spleen, thymus, and reproductive organs; immaturity of the testes; and cell debris in the epididymides were affected by the reduction in body weight in PHMG·HCl-exposed groups. In conclusion, two-week repeated whole-body inhalation exposure of rats to PHMG·HCl reveled toxic effects on the respiratory system and secondary effects on other organs. The results of this study indicate that the no observable adverse effect level (NOAEL) for PHMG·HCl is below 1 mg/m3.

12.
Appl Opt ; 58(36): 9940-9948, 2019 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-31873640

RESUMEN

A compact laser-induced breakdown spectroscopy (LIBS) instrument and a simple sample preparation method were developed for rapid on-site analysis of Mg, Ca, and K in edible sea salt products. The LIBS instrument was assembled using a small diode-pumped solid-state laser and a handheld spectrometer. Aqueous solutions of salts were prepared and sampled by using pieces of filter papers. The dried filter paper was attached on the flat surface of a silicon wafer and then analyzed by LIBS. Calibration curves were obtained using binary mixtures of ${\rm NaCl} {-} {{\rm MgSO}_4}$NaCl-MgSO4, ${\rm NaCl} {-} {{\rm CaCl}_2}$NaCl-CaCl2, and NaCl-KCl and used to estimate the concentrations of Mg, Ca, and K in 13 edible sea salt products. Matrix effects on the results from LIBS were identified in comparison with those from inductively coupled plasma optical emission spectroscopy. This indicates that the matrix of sea salt samples is significantly different from that of the binary mixture standards. The sea salts with known concentrations of Mg, Ca, and K were employed to match the matrices of samples and standards. This improved analysis accuracy remarkably. Furthermore, an alternative indirect method for estimating the concentration of K was suggested on the basis of the strong positive correlations observed between the concentrations of Mg and K in the sea salt samples.

13.
J Toxicol Pathol ; 32(4): 311-317, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31719760

RESUMEN

Polyhexamethylene guanidine hydrochloride (PHMG-HCl), an antimicrobial additive in humidifier disinfectants, was associated with the pulmonary disease outbreak in South Korea. However, PHMG-mediated oxidative stress has only been studied in vitro. Here, we evaluated PHMG-induced oxidative stress in the lungs of rats exposed to PHMG-HCl. Male F344 rats were exposed to different concentrations of PHMG-HCl for 13-weeks via whole-body inhalation. Histopathological examination of the exposed rats showed the presence of lung lesions, including alveolar/interstitial fibrosis with inflammatory cell infiltration, bronchioalveolar hyperplasia, bronchiolar/alveolar squamous metaplasia, bronchial/bronchiolar epithelial detachment, and alveolar hemorrhage. Immunohistochemical analysis showed that 4-hydroxynonenal (4-HNE) was expressed in the bronchiolar epithelium, mainly in Clara cells and macrophages of the fibrotic tissue. The number of 4-HNE-positive cells increased significantly in a dose-dependent manner. This is the first in vivo study to report PHMG-induced oxidative stress. Our study provides clues to elucidate the mechanisms underlying PHMG-induced damage in patients affected by humidifier disinfectants.

14.
Environ Toxicol ; 32(4): 1226-1240, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27441813

RESUMEN

Although the use of lanthanum has increased in field of high-tech industry worldwide, potential adverse effects to human health and to the environment are largely unknown. The present study aimed to investigate the potential toxicity of nano-sized lanthanum oxide (La2 O3 ) following repeated inhalation exposure in male Sprague-Dawley rats. Male rats were exposed nose-only to nano-sized La2 O3 for 28 days (5 days/week) at doses of 0, 0.5, 2.5, and 10 mg/m3 . In the experimental period, we evaluated treatment-related changes including clinical signs, body weight, hematology, serum biochemistry, necropsy findings, organ weight, and histopathology findings. We also analyzed lanthanum distribution in the major organs and in the blood, bronchoalveolar lavage fluids (BALF), and oxidative stress in lung tissues. Lanthanum level was highest in lung tissues and showed a dose-dependent relation. Alveolar proteinosis was observed in all treatment groups and was accompanied by an increase in lung weight; moreover, lung inflammation was observed in the 2.5 mg/m3 and higher dose groups and was accompanied by an increase in white blood cells. In the BALF, total cell counts including macrophages and neutrophils, lactate dehydrogenase, albumin, nitric oxide, and tumor necrosis factor-alpha increased significantly in all treatment groups. Furthermore, these changes tended to deteriorate in the 10 mg/m3 group at the end of the recovery period. In the present experimental conditions, we found that the lowest-observed-adverse-effect level of nano-sized La2 O3 was 0.5 mg/m3 in male rats, and the target organ was the lung. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1226-1240, 2017.


Asunto(s)
Lantano/química , Pulmón/efectos de los fármacos , Nanopartículas del Metal/toxicidad , Estrés Oxidativo/efectos de los fármacos , Óxidos/química , Administración por Inhalación , Animales , Peso Corporal/efectos de los fármacos , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/citología , L-Lactato Deshidrogenasa/sangre , Pulmón/metabolismo , Pulmón/patología , Macrófagos/citología , Masculino , Nanopartículas del Metal/química , Neutrófilos/citología , Óxido Nítrico/análisis , Ratas , Ratas Sprague-Dawley , Factor de Necrosis Tumoral alfa/sangre
16.
Environ Technol ; 36(1-4): 254-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25413120

RESUMEN

In this study, Fe(VI) was applied to treat three mine tailings containing different amounts of sulphides and heavy metals. Oxidation of sulphides by Fe(VI) was studied at pH 9.2 with variation of solid to solution ratio, Fe(VI) concentration and injection number of Fe(VI) solution. The major dissolved products from the treatment of mine tailings with Fe(VI) solution were sulphate and arsenic. Oxidation efficiency of sulphides was evaluated by reduction efficiency of Fe(VI) as well as by measurement of dissolved sulphate concentration. Even though inorganic composition of three mine tailings was different, reduction fraction of Fe(VI) was quite similar. This result can suggest that Fe(VI) was involved in several other reactions in addition to oxidation of sulphides. Oxidation of sulphides in mine tailing was greatly dependent on the total amount of sulphides as well as kinds of sulphides complexed with metals. Over the five consecutive injections of Fe(VI) solution, dissolved sulphate concentration was greatly decreased by each injection and no more dissolved sulphate was observed at the fifth injection. While dissolved arsenic was decreased lineally up to the fifth injection. Sulphate generation was slightly increased for all mine tailings as Fe(VI) concentration was increased; however, enhancement of oxidation efficiency of sulphides was not directly proportional to the initial Fe(VI) concentration.


Asunto(s)
Residuos Industriales/prevención & control , Hierro/química , Metales Pesados/química , Minería , Eliminación de Residuos/métodos , Sulfuros/química , Ensayo de Materiales , Metales Pesados/aislamiento & purificación , Oxidación-Reducción , Sulfuros/aislamiento & purificación
17.
Microbiol Resour Announc ; : e0034524, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38785431

RESUMEN

We report the whole genome sequence of Microbacterium rhizosphaerae KACC 19337T. The genome consists of a 4.05-Mb circular chromosome, with a G + C content of 69.7 %, and 3,627 total coding genes predicted.

18.
Appl Spectrosc ; 77(12): 1351-1361, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37844583

RESUMEN

In this work, we applied a hydrophilicity-enhanced solid substrate and an alternating laser-ablation data sampling (ALADS) scheme to improve laser-induced breakdown spectroscopy (LIBS) measurement precision and demonstrated the performance in analyzing K, Mg, Ca, and S contained in commercially available edible salt products. Five edible salt products from Australia, Bolivia, France, and South Korea were dissolved in water and a tiny volume of each solution was dropped on the solid substrate, that is, a miniaturized salt pond. After being dried, the residual salt crystals distributed still inhomogeneously, but the homogeneity could be significantly improved in comparison with that from typical drop-and-dry methods. The ALADS scheme was applied to extract three precise measurements from 9798 single-shot LIBS spectra covering the entire salt pond. The measurements obtained by ALADS were found to agree well with one another regardless of the inhomogeneous distribution of salt crystals. As a result, the measurement precision was proved remarkably. Limits of detection for K, Mg, Ca, and S were estimated to be 0.64, 1.7, 14, and 530 mg/kg, respectively, which are enough to analyze those elements contained in salts typically at the level of 100 parts per million (ppm) to ∼3 wt% for the purpose of salt quality assessment.

19.
Appl Spectrosc ; 77(4): 371-381, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36650747

RESUMEN

A simple cost-effective laser-induced breakdown spectroscopy (LIBS) instrument was used for quantification of major elements in several nickel alloys and also sorting them. A compact low-power diode-pumped solid-state laser and a miniature low-resolution spectrometer were assembled for the LIBS instrument. Material properties of the nickel alloys depend mainly on the composition of the major elements, Ni, Cr, and Fe, ranging from a few to ∼60 wt%. The emission peaks at 547.7 nm, 520.4 nm, and 438.1 nm for Ni, Cr, and Fe, respectively, were chosen for this analysis. The analytical performance was found to be enough for the quantification of Ni, Cr, and Fe in the nickel alloys. Limits of detection and accuracy were estimated to be a few weight percent (wt%) and measurement precisions were less than 10% in terms of relative standard deviation. The calibration performance of this intensity-based method was compared with that of the "ratio method" which is used in conventional optical emission spectroscopy analyses. The comparison indicates that the intensity-based method is more appropriate with the low-performance LIBS instrument that detects emission peaks of only a few major elements. Also, multivariate modeling of the six different nickel alloy samples based on the emission peak intensities of Ni, Cr, and Fe was performed using k-nearest neighbors (KNN) and linear discriminant analysis (LDA). The KNN and ordinary LDA models showed 95.0% and 98.3% classification correctness for the separate test data set, respectively. To improve classification performance further, the two-step LDA model was trained. In this approach, the two closest sample classes responsible for the decrease in the classification correctness were separately modeled in the second step to exploit their difference effectively. The two-step LDA model showed 100% correctness in classifying the test objects. Our results indicate that such a low-performance LIBS instrument can be effectively utilized for quantitative analysis of the major elements in the nickel alloys and their rapid identification or sorting in combination with an appropriate multivariate modeling algorithm.

20.
Food Chem ; 399: 133956, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36027807

RESUMEN

Laser-induced breakdown spectroscopy (LIBS) and near-infrared (NIR) spectroscopy were combined to enhance discrimination of soybean paste samples according to geographical origin. Since element and organic component compositions of soybean pastes depend on soybean cultivation areas and fermentation conditions, utilization of two complementary spectroscopic signatures would be synergetic for the discrimination. When the areas of C (AC) and Ca (ACa) peaks in the LIBS spectra were used as the inputs for linear discriminant analysis, the accuracy was 95.4%. The accuracy became 92.1%, when the principal component (PC) scores obtained by principal component analysis of the NIR spectra were employed. To enhance NIR discrimination, two-trace two-dimensional (2T2D) correlation analysis was adopted to recognize minute spectral differences. With using the 1st/2nd PC scores of 2T2D slice spectra, accuracy increased to 95.0%. When the ratios of ACa/AC and the 2nd PC scores of the samples were combined together, the accuracy improved to 99.6%.


Asunto(s)
Fabaceae , Glycine max , Análisis Discriminante , Geografía , Análisis de Componente Principal , Espectroscopía Infrarroja Corta/métodos
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