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1.
Animals (Basel) ; 14(3)2024 Jan 29.
Article in English | MEDLINE | ID: mdl-38338080

ABSTRACT

This review examines the significant role of methane emissions in the livestock industry, with a focus on cattle and their substantial impact on climate change. It highlights the importance of accurate measurement and management techniques for methane, a potent greenhouse gas accounting for 14-16% of global emissions. The study evaluates both conventional and AI-driven methods for detecting methane emissions from livestock, particularly emphasizing cattle contributions, and the need for region-specific formulas. Sections cover livestock methane emissions, the potential of AI technology, data collection issues, methane's significance in carbon credit schemes, and current research and innovation. The review emphasizes the critical role of accurate measurement and estimation methods for effective climate change mitigation and reducing methane emissions from livestock operations. Overall, it provides a comprehensive overview of methane emissions in the livestock industry by synthesizing existing research and literature, aiming to improve knowledge and methods for mitigating climate change. Livestock-generated methane, especially from cattle, is highlighted as a crucial factor in climate change, and the review underscores the importance of integrating precise measurement and estimation techniques for effective mitigation.

3.
Sci Rep ; 9(1): 11249, 2019 Aug 02.
Article in English | MEDLINE | ID: mdl-31375722

ABSTRACT

The phase velocity of the wakefield of a laser wakefield accelerator can, theoretically, be manipulated by shaping the longitudinal plasma density profile, thus controlling the parameters of the generated electron beam. We present an experimental method where using a series of shaped longitudinal plasma density profiles we increased the mean electron peak energy more than 50%, from 175 ± 1 MeV to 262 ± 10 MeV and the maximum peak energy from 182 MeV to 363 MeV. The divergence follows closely the change of mean energy and decreases from 58.9 ± 0.45 mrad to 12.6 ± 1.2 mrad along the horizontal axis and from 35 ± 0.3 mrad to 8.3 ± 0.69 mrad along the vertical axis. Particle-in-cell simulations show that a ramp in a plasma density profile can affect the evolution of the wakefield, thus qualitatively confirming the experimental results. The presented method can increase the electron energy for a fixed laser power and at the same time offer an energy tunable source of electrons.

4.
Rev Sci Instrum ; 89(2): 025110, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29495828

ABSTRACT

A novel gas target for interactions between high power lasers and gaseous medium, especially for laser wakefield accelerators, has been designed, manufactured, and characterized. The gas target has been designed to provide a uniform density profile along the central gas cell axis by combining a gas cell and slit nozzle. The gas density has been tuned from ∼1017 atoms/cm3 to ∼1019 atoms/cm3 and the gas target length can be varied from 0 to 10 cm; both changes can be made simultaneously while keeping the uniform gas profile. The gas density profile inside the gas cell has been measured using interferometry and validated using computational fluid dynamics.

5.
Int J Infect Dis ; 66: 45-50, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29031605

ABSTRACT

BACKGROUND: In June 2015, a local public health laboratory was notified that students had developed gastroenteritis symptoms after attending a camp. An outbreak investigation was conducted to determine the extent and cause of the outbreak. METHOD: A retrospective cohort study was conducted to determine the correlations between the illness and specific exposures at the school camp. All attendees were interviewed with a standard questionnaire that addressed clinical symptoms, food consumption, and environmental exposures. Clinical specimens were cultured using standard microbiological methods for bacterial and viral pathogens. The genetic relationships of all isolates were determined using pulsed-field gel electrophoresis (PFGE). RESULTS: A total 188 patients with symptoms of diarrhoea, abdominal pain, and nausea were identified. The completed questionnaires suggested that the consumption of drinking water was likely to be linked to this outbreak. Using microbiological methods, enterohaemorrhagic Escherichia coli, enteropathogenic E. coli, and enteroaggregative E. coli were isolated, and the isolates from both patient stool and environmental water samples displayed indistinguishable XbaI-PFGE patterns. The water system in the camp used groundwater drawn from a private underground reservoir for cooking and drinking. The environmental investigation revealed some problems with the water supply system, such as the use of inappropriate filters in the water purifier and a defect in the pipeline between the reservoir and the chlorination device. CONCLUSIONS: This outbreak points to the importance of drinking water quality management in group facilities where underground water is used and emphasizes the need for periodic sanitation and inspection to prevent possible waterborne outbreaks.


Subject(s)
Camping , Drinking Water/microbiology , Escherichia coli Infections/etiology , Waterborne Diseases/etiology , Cohort Studies , Diarrhea/epidemiology , Diarrhea/etiology , Diarrhea/microbiology , Disease Outbreaks , Electrophoresis, Gel, Pulsed-Field , Escherichia coli/isolation & purification , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Gastroenteritis/epidemiology , Humans , Retrospective Studies , Schools , Waterborne Diseases/epidemiology
6.
Angew Chem Int Ed Engl ; 56(43): 13387-13391, 2017 10 16.
Article in English | MEDLINE | ID: mdl-28799217

ABSTRACT

N-Alkynylindoles were divergently cyclized for the synthesis of multifused N-heterocycles. An ortho-aryl palladium species was added to the α position of an ynamine to generate (Z)-6-alkylidene/benzylidene-6H-isoindolo[2,1-a]indoles, while Pt-catalyzed ß-addition through π-activation gave 5-alkyl/arylindolo[2,1-a]isoquinolines. Double cyclizations using PdCl2 and oxidant afforded bright yellow benzo[7,8]indolizino[2,3,4,5-ija]quinolines, the synthesis of which was also demonstrated in a different synthetic route.

7.
J Clin Virol ; 94: 63-66, 2017 09.
Article in English | MEDLINE | ID: mdl-28759774

ABSTRACT

BACKGROUND: Hepatitis A virus (HAV), a major cause of acute hepatitis, has had the highest occurrence among group 1 nationally notifiable infectious diseases in Korea since 2010.Recently,the annual increase in the HAV infection rate among young adults has become a public health concern. OBJECTIVES: The aim of this study was to describe an outbreak of acute hepatitis in a residential facility in April 2015 and to identify potential sources of this outbreak. STUDY DESIGN: Sera from all exposed residents were tested for anti-HAV IgM or IgG antibodies by ELISA. Clinical (sera and stool) and environmental samples were screened for the presence of HAV RNA using one-step RT-PCR and nested PCR. The VP3-VP1 regions of HAV were analyzed using the BLAST database and MEGA7 software. RESULTS: Of the 82 persons in the facility, 12 (14.6%, including 10 residents and 2 health care workers) were diagnosed with hepatitis A. Clinical symptoms were evident in 9 individuals, one of whom died, and the remaining four patients were asymptomatic. Traceback investigation revealed that HAV-RNA (genotype IA) was detected in the patients' stools and the groundwater used in the facility. CONCLUSIONS: We described an HAV outbreak in a facility for the disabled due to using a water supply that was mixed with contaminated groundwater. Therefore, HAV vaccination and periodic water inspections in group facilities should be emphasized to prevent HAV infection.


Subject(s)
Disease Outbreaks/statistics & numerical data , Hepatitis A virus/genetics , Hepatitis A/epidemiology , Water Microbiology , Adolescent , Adult , Genotype , Hepatitis A/immunology , Hepatitis A/transmission , Hepatitis A Antibodies/blood , Hepatitis A virus/immunology , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Phylogeny , Republic of Korea/epidemiology , Water Supply , Young Adult
8.
Org Lett ; 19(15): 3994-3997, 2017 08 04.
Article in English | MEDLINE | ID: mdl-28727437

ABSTRACT

A copper-catalyzed regiocontrolled three-component reaction afforded diversified 4-aminoquinolines using nitriles, diaryliodoniums, and ynamides. The C7-substituted regioisomers were formed regioselectively when meta-substituted phenyliodonium salts were used. [1,3] N-to-C rearrangement of the products to quinolin-4-ylmethanesulfonamides and simultaneous deprotection of benzyl and sulfonamide group were newly developed. Finally, antimalarial CK-2-68 was successfully prepared.

9.
Article in English | MEDLINE | ID: mdl-28652229

ABSTRACT

We investigated an outbreak of enterotoxigenic Escherichia coli (ETEC) O159:H20 associated with the consumption of a tossed-noodle dish in a high school in 2016. Thirty-three ETEC strains isolated from clinical and food samples were genetically indistinguishable. The outbreak strains were resistant to third-generation cephalosporins and harbored a blaCTX-M-15 gene on a 97-kb self-transferable IncK plasmid. This is the first outbreak caused by CTX-M-15-producing ETEC strains.


Subject(s)
Enterotoxigenic Escherichia coli/metabolism , Escherichia coli Infections/epidemiology , beta-Lactamases/metabolism , Cephalosporins/therapeutic use , Disease Outbreaks , Enterotoxigenic Escherichia coli/drug effects , Humans , Plasmids/genetics , Republic of Korea/epidemiology
10.
Jpn J Infect Dis ; 70(3): 320-322, 2017 May 24.
Article in English | MEDLINE | ID: mdl-28003591

ABSTRACT

We compared 47 enterohemorrhagic Escherichia coli (EHEC) O157 isolates with 184 EHEC non-O157 isolates from Korean patients with diarrhea. In the O157 group, the strains harboring both Shiga toxin genes (stx1 and stx2) were detected with highest frequency, whereas the strains harboring only stx1 gene were most frequently detected in the non-O157 group. Eight virulence genes (eaeA, hlyA, ehx, iha, efa1, tir, toxB, and espA) were found to show a higher frequency of occurrence in the O157 group than in the non-O157 group. In addition, the symptom of bloody diarrhea was exhibited at a higher rate in the O157 group (51.1%) than in the non-O157 group (16.8%). Our findings demonstrate that EHEC O157 strains are more frequently implicated in cases of bloody diarrhea in the Korean population than EHEC non-O157 strains.


Subject(s)
Diarrhea/microbiology , Enterohemorrhagic Escherichia coli/classification , Escherichia coli Infections/microbiology , O Antigens/analysis , Shiga Toxin 1/genetics , Shiga Toxin 2/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Diarrhea/epidemiology , Diarrhea/pathology , Enterohemorrhagic Escherichia coli/genetics , Enterohemorrhagic Escherichia coli/isolation & purification , Enterohemorrhagic Escherichia coli/pathogenicity , Escherichia coli Infections/epidemiology , Escherichia coli Infections/pathology , Female , Humans , Infant , Infant, Newborn , Korea/epidemiology , Male , Middle Aged , Serogroup , Virulence Factors/genetics , Young Adult
12.
Sci Signal ; 9(452): ra106, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27803284

ABSTRACT

The roles of photoreceptors and their associated signaling mechanisms have been extensively studied in plant photomorphogenesis with a major focus on the photoresponses of the shoot system. Accumulating evidence indicates that light also influences root growth and development through the light-induced release of signaling molecules that travel from the shoot to the root. We explored whether aboveground light directly influences the root system of Arabidopsis thaliana Light was efficiently conducted through the stems to the roots, where photoactivated phytochrome B (phyB) triggered expression of ELONGATED HYPOCOTYL 5 (HY5) and accumulation of HY5 protein, a transcription factor that promotes root growth in response to light. Stimulation of HY5 in response to illumination of only the shoot was reduced when root tissues carried a loss-of-function mutation in PHYB, and HY5 mutant roots exhibited alterations in root growth and gravitropism in response to shoot illumination. These findings demonstrate that the underground roots directly sense stem-piped light to monitor the aboveground light environment during plant environmental adaptation.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Light , Phytochrome B/metabolism , Plant Roots/metabolism , Plant Stems/metabolism , Signal Transduction/physiology , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Gravitropism/physiology , Phytochrome B/genetics , Plant Roots/genetics , Plant Stems/genetics
13.
Foodborne Pathog Dis ; 13(10): 535-543, 2016 10.
Article in English | MEDLINE | ID: mdl-27557346

ABSTRACT

BACKGROUND: Two outbreaks of gastroenteritis occurred in South Korea, affecting a middle school in the Jeollanam-do province in 2013 (Outbreak 1) and 10 schools in the Incheon province in 2014 (Outbreak 2). We investigated the outbreaks to identify the pathogen and mode of transmission. METHODS: A retrospective cohort study was conducted in the Outbreak 1; and case-control studies were performed for the Outbreak 2. Samples from students, environments, and preserved food items were collected and pulsed-field gel electrophoresis (PFGE) was conducted to identify strains of pathogen. RESULTS: We identified 167 and 1022 students who met the case definition (≥3 loose stools in any 24-h period) in the Outbreaks 1 and 2, respectively. The consumption of cabbage kimchi and young radish kimchi were significantly associated with the illness. Adjusted odds ratios of kimchi were 2.62-11.74. In the Outbreak 1, cabbage kimchi was made and consumed in the school restaurant and in the Outbreak 2, young radish kimchi was supplied by food company X and distributed to all the 10 schools in the Incheon province. Enterotoxigenic Escherichia coli (ETEC) O6 was isolated from fecal samples in 375 cases (33.9%) and from kimchi samples. PFGE patterns of the outbreak strains isolated from cases and food were indistinguishable in each outbreak. CONCLUSION: The suspected food vehicle in these two consecutive outbreaks was kimchi contaminated with ETEC O6. We recommend continued monitoring and stricter sanitation requirements for the food supply process in Korea, especially in relation to kimchi.


Subject(s)
Disease Outbreaks , Enterotoxigenic Escherichia coli/growth & development , Escherichia coli Infections/etiology , Food Contamination , Food, Preserved/adverse effects , Foodborne Diseases/etiology , Gastroenteritis/etiology , Brassica/adverse effects , Brassica/microbiology , Case-Control Studies , Cohort Studies , Enterotoxigenic Escherichia coli/classification , Enterotoxigenic Escherichia coli/isolation & purification , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Escherichia coli Infections/transmission , Feces/microbiology , Fermentation , Food Services , Food, Preserved/microbiology , Foodborne Diseases/epidemiology , Foodborne Diseases/microbiology , Gastroenteritis/epidemiology , Gastroenteritis/microbiology , Humans , Lunch , Molecular Typing , Plant Leaves/adverse effects , Plant Leaves/microbiology , Plant Roots/adverse effects , Plant Roots/microbiology , Raphanus/adverse effects , Raphanus/microbiology , Republic of Korea/epidemiology , Retrospective Studies , Risk , Schools
14.
Chem Commun (Camb) ; 52(34): 5884-7, 2016 Apr 30.
Article in English | MEDLINE | ID: mdl-27052458

ABSTRACT

This communication reports a new nanocatalytic scheme based on the facts that the redox reaction between a highly outer-sphere-reaction-philic (OSR-philic) species and a highly inner-sphere-reaction-philic (ISR-philic) species is slow and that an OSR- and ISR-philic Au-nanocatalyst label can mediate the two different types of redox species. This scheme allows highly sensitive and incubation free detection of creatine kinase-MB.


Subject(s)
2,2'-Dipyridyl/analogs & derivatives , Biosensing Techniques/methods , Gold/chemistry , Hydrazines/chemistry , Organometallic Compounds/chemistry , 2,2'-Dipyridyl/chemistry , Animals , Catalysis , Creatine Kinase, MB Form/blood , Electrochemical Techniques , Electrodes , Humans , Immunoglobulin G/blood , Limit of Detection , Mice , Nanoparticles , Oxidation-Reduction , Tin Compounds
15.
Org Lett ; 18(9): 2204-7, 2016 05 06.
Article in English | MEDLINE | ID: mdl-27097044

ABSTRACT

A base-controlled Cu-catalyzed tandem cyclization/alkynylation of propargylic amines provides rapid access to functionalized indolizine derivatives under mild reaction conditions. The reaction first proceeded via a 5-endo-dig aminocupration, followed by a coupling between the copper-bound intermediate and alkynyl bromide, to afford the products in good to excellent yields. The successful tandem reaction is attributed to the unique property of the bases, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) and MTBD (7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene used).

17.
Sci Rep ; 6: 19696, 2016 Jan 25.
Article in English | MEDLINE | ID: mdl-26806215

ABSTRACT

We developed an ultra-high speed photonic sintering method involving flash white light (FWL) combined with near infrared (NIR) and deep UV light irradiation to produce highly conductive copper nano-ink film. Flash white light irradiation energy and the power of NIR/deep UV were optimized to obtain high conductivity Cu films. Several microscopic and spectroscopic characterization techniques such as scanning electron microscopy (SEM), a x-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy were employed to characterize the Cu nano-films. Optimally sintered Cu nano-ink films produced using a deep UV-assisted flash white light sintering technique had the lowest resistivity (7.62 µΩ·cm), which was only 4.5-fold higher than that of bulk Cu film (1.68 µΩ•cm).

18.
Jpn J Infect Dis ; 68(6): 514-9, 2015.
Article in English | MEDLINE | ID: mdl-25971323

ABSTRACT

In June 2013, a diarrheal outbreak occurred among high school students in Incheon, South Korea. We investigated the outbreak to identify the pathogen and mode of transmission. A case-control study using a self-administered questionnaire was conducted by local authorities and the Korean Centers for Disease Control and Prevention. Bacterial cultures of stool samples, environmental samples, and samples of preserved food items were prepared. PCR, serotyping, and pulsed-field gel electrophoresis (PFGE) were used to identify and characterize the outbreak-related pathogen. We identified 54 cases of gastroenteritis, with symptoms including diarrhea, abdominal pain, and nausea. None of the food items served in the high school cafeteria were significantly associated with illness, although the odds ratio for kippered trotters mixed with vegetables was relatively high (odds ratio: 2.92, 95% confidence interval: 0.62-13.69). Enteroaggregative Escherichia coli (EAEC) was isolated from this item and the stool samples from 22 symptomatic students and 4 asymptomatic food handlers. The PFGE patterns of EAEC isolated from these sources were indistinguishable. This outbreak was caused by EAEC, and kippered trotters mixed with vegetables, perhaps contaminated by asymptomatic food handlers, were linked to the outbreak. This case-control study highlights the importance of safe food preparation.


Subject(s)
Diarrhea/epidemiology , Disease Outbreaks , Escherichia coli Infections/epidemiology , Escherichia coli/isolation & purification , Foodborne Diseases/epidemiology , Gastroenteritis/epidemiology , Adolescent , Case-Control Studies , Diarrhea/microbiology , Electrophoresis, Gel, Pulsed-Field , Escherichia coli/classification , Escherichia coli Infections/microbiology , Female , Foodborne Diseases/microbiology , Gastroenteritis/microbiology , Genotype , Humans , Male , Molecular Typing , Republic of Korea/epidemiology , Schools , Serogroup , Serotyping , Surveys and Questionnaires
19.
Foodborne Pathog Dis ; 11(10): 775-81, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25054886

ABSTRACT

UNLABELLED: Background: In May 2013, an outbreak of gastroenteritis occurred in a high school in Incheon, South Korea. We investigated the outbreak in order to identify the pathogen and mode of transmission. MATERIALS AND METHODS: A case-control study was performed using standardized questionnaires with a case definition of illness with diarrhea. Stool samples, environmental samples, and samples from preserved food items were collected to test pathogens. Pulsed-field gel electrophoresis (PFGE) was performed on the outbreak-related Escherichia coli strains. RESULTS: Thirty-three people (attack rate: 2.5%) met the case definition, and the pattern of the epidemic curve suggested a point-source outbreak. The common symptoms of cases were diarrhea (100.0%), abdominal pain (75.8%), chills (45.5%), and nausea (39.4%). Cases were found to be 8.26 times more likely to have eaten spicy fish soup with cod (95% confidence interval: 1.05-65.01). Consumption of egg soup with spring onions or braised eggs with razor clam flesh was significantly associated with illness. Atypical enteropathogenic E. coli O157:H45 was isolated from samples of 9 cases (27.3%) and tuna bibimbap. PFGE patterns of all tested isolates of O157 serotype were indistinguishable. CONCLUSIONS: This outbreak was caused by atypical enteropathogenic E. coli O157:H45 and the food vehicle was suspected to be tuna bibimbap. The statistical analysis was not in concordance with the microbiologic tests, probably owing to low pathogenicity of atypical enteropathogenic E. coli O157. This is the first report of an outbreak caused by atypical enteropathogenic E. coli O157.


Subject(s)
Diarrhea/epidemiology , Disease Outbreaks , Escherichia coli Infections/epidemiology , Escherichia coli O157/isolation & purification , Foodborne Diseases/microbiology , Case-Control Studies , Diarrhea/microbiology , Electrophoresis, Gel, Pulsed-Field , Escherichia coli O157/classification , Food Contamination/analysis , Food Microbiology , Foodborne Diseases/epidemiology , Humans , Republic of Korea/epidemiology , Serotyping
20.
PLoS One ; 9(5): e96896, 2014.
Article in English | MEDLINE | ID: mdl-24841334

ABSTRACT

Enterotoxigenic Escherichia coli (ETEC) is one of the major causes of infectious diarrhea in developing countries. In order to characterize the molecular features of human ETEC isolates from Korea, we investigated the profiles of enterotoxin and colonization factor (CF) genes by polymerase chain reaction (PCR) and performed multilocus sequence typing (MLST) with a total of 291 ETEC strains. The specimens comprised 258 domestic strains isolated from patients who had diarrhea and were from widely separated geographic regions in Korea and 33 inflow strains isolated from travelers visiting other Asian countries. Heat-stable toxin (STh)-possessing ETEC strains were more frequent than heat-labile toxin (LT)-possessing ETEC strains in the domestic isolates, while the detection rates of both enterotoxin genes were similar in the inflow isolates. The profile of CF genes of domestic isolates was similar to that of inflow isolates and the major CF types of the strains were CS3-CS21-CS1/PCF071 and CS2-CS3-CS21. Most of these 2 CF types were detected in ETEC strains that possess both lt and sth genes. The major MLSTST types of domestic isolates were ST171 and ST955. Moreover, the 2 major CF types were usually found concomitantly with the 2 major MLST STs, ST171 and ST955. In conclusion, our genotyping results may provide useful information for guiding the development of geographically specific vaccines against human ETEC isolates.


Subject(s)
Enterotoxigenic Escherichia coli/metabolism , Enterotoxigenic Escherichia coli/drug effects , Enterotoxigenic Escherichia coli/genetics , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Genotype , Humans , Microbial Sensitivity Tests , Multilocus Sequence Typing , Republic of Korea
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