Publications by authors named "Kyeongnam Kim"

The increase in nursery plant trade has heightened the risk of invasions of exotic pests, such as mealybugs and nematodes. In this study, we first evaluated the feasibility of using the currently approved methyl bromide (MB) treatment for imported nursery plants (IMP) against the longtailed mealybug, Pseudococcus longispinus. We then assessed ethyl formate (EF) fumigation as a potential MB-alternative treatment and tested 2 nematicides against the root-lesion nematode, Pratylenchus penetrans C.

View Article and Find Full Text PDF
Article Synopsis
  • Plastic pollution is a growing concern, as evidenced by the discovery of microplastics (MP) in freshwater fishes in the Han River tributary, with 38 fish analyzed showing significant contamination levels.
  • The prevalent sizes of microplastics found in these fish ranged from 45 to 100 μm, primarily in the form of fragments, with polypropylene being the most common type.
  • The study highlights that the concentration of microplastics in smaller fish depends on their habitat and size, emphasizing the need for continued monitoring of microplastics in freshwater ecosystems.
View Article and Find Full Text PDF

The prevalence of microplastic (MP) contamination has become a significant environmental concern due to its pervasive nature and persistent effects. While sediments are considered major repositories for MPs, information on their spatial distribution within these matrices is insufficient. This research examined both the horizontal and vertical presence of MPs in the sediments surrounding Lake Paldang in South Korea, alongside a comprehensive evaluation of the physicochemical characteristics of the samples obtained.

View Article and Find Full Text PDF

Cyanobacterial harmful algal blooms (cyanoHABs), which are a form of microbial dysbiosis in freshwater environments, are an emerging environmental and public health concern. Additionally, the freshwater environment serves as a reservoir of antibiotic resistance genes (ARGs), which pose a risk of transmission during microbial dysbiosis, such as cyanoHABs. However, the interactions between potential synergistic pollutants, cyanoHABs, and ARGs remain poorly understood.

View Article and Find Full Text PDF

Fungal infection and mycotoxin contamination are major hazards to the safe storage and distribution of foods and feeds consumed by humans and livestock. This study investigated the antifungal and antiaflatoxigenic activities of massoia essential oil (MEO) and its major constituent, C10 massoia lactone (C10), against aflatoxin B (AFB)-producing ATCC 22546. Their antifungal activities were evaluated using a disc diffusion assay, agar dilution method, and a mycelial growth inhibition assay with the AFB analysis using liquid chromatography triple quadrupole mass spectrometry.

View Article and Find Full Text PDF

An intermittent fasting regimen is widely perceived to lead to various beneficial health effects, including weight loss, the alleviation of insulin resistance, and the restructuring of a healthy gut microbiome. Because it shares certain commonalities with this dietary intervention, Ramadan fasting is sometimes misinterpreted as intermittent fasting, even though there are clear distinctions between these two regimens. The main purpose of this study is to verify whether Ramadan fasting drives the same beneficial effects as intermittent fasting by monitoring alterations in the gut microbiota.

View Article and Find Full Text PDF

The effects of climate change and shifting consumer preferences for tropical/subtropical mango fruits have accelerated their greenhouse cultivation in South Korea, which has consequently exacerbated the risk of unexpected or exotic insect pest outbreaks. This study used the pest risk analysis (PRA) of greenhouse-cultivated mangoes provided by the Animal & Plant Quarantine Agency in Korea to evaluate the potential of ethyl formate (EF) fumigation as a new pest management strategy against the yellow tea thrips (), which is considered a surrogate pest in the thrips group according to the PRA. The efficacy and phytotoxicity of EF were evaluated in greenhouse-cultivated mango tree (Irwin variety) and post-harvest mango fruit scenarios.

View Article and Find Full Text PDF

(Hemiptera: Aleyrodidae), commonly known as greenhouse whitefly, is one of the main insect pests of Oriental melon ( var L.) in South Korea. is of concern as a quarantine pest for the exportation of in Southeast Asian countries.

View Article and Find Full Text PDF

Piperlongumine (PL) and piperine (PP) are alkaloids presented in long pepper (Piper longum), and they exhibit various biological activities, especially anti-cancer properties. With these regards, they are considered as future medicines with high potential. Even they are exposed to humans such a long time, their potential toxicities in the environment have not been studied.

View Article and Find Full Text PDF

Trifloxystrobin (TFS) is one of the extensively used strobilurin fungicides, which is composed of four enantiomers and its active form is E,E-TFS. In this study, we assess the acute toxicity of four enantiomers, E,E-, E,Z-, Z,E-, and Z,Z-TFS in zebrafish (Danio rerio) embryos. Among the four enantiomers, only E,E-TFS was found to be acutely toxic, with an estimated LC value of 0.

View Article and Find Full Text PDF

Combined toxicity can occur in the environment according to the combination of single substances, and the combination works additively or in a synergistic or antagonistic mode. In our study, 3,5,6-trichloro-2-pyridinol (TCP) and 2-(bromomethyl)naphthalene (2-BMN) were used to measure combined toxicity in zebrafish (Danio rerio) embryos. As the lethal concentration (LC) values were obtained through single toxicity, the lethal effects at all combinational concentrations were considered synergistic by the Independent Action model.

View Article and Find Full Text PDF

Regulation of melanin production via the MC1R signaling pathway is a protective mechanism of the skin of living organisms against exposure to ultraviolet rays. The discovery of human skin-whitening agents has been one of the most intense pursuits of the cosmetic industry. The MC1R signaling pathway is activated by its agonist, alpha-melanocyte stimulating hormone (α-MSH), and mainly regulates melanogenesis.

View Article and Find Full Text PDF

Pymetrozine (PYM) is worldwide used to control sucking insect pests in rice-cultivated fields and it is degraded into various metabolites including 3-pyridinecarboxaldehyde (3-PCA). These two pyridine compounds were used to determine their impacts on aquatic environments, particularly on the aquatic animal model zebrafish (Danio rerio). PYM did not show acute toxicities in terms of lethality, hatching rate, and phenotypic changes in zebrafish embryos in the tested ranges up to a concentration of 20 mg/L.

View Article and Find Full Text PDF

Phosphine (PH) is an ideal fumigant alternative on methyl bromide (MB) as MB has been classified as an ozone-depleting substance. However, several challenges limit its efficient use in crop production, including the emergence of PH-resistant insect pests and the incidence of phytotoxic effects on nursery plants. Therefore, this study aims to elucidate the mechanism underlying PH phytotoxicity in plants using transcriptomic techniques.

View Article and Find Full Text PDF

Polyhalogenated polycyclic aromatic hydrocarbons (HPAHs) represent a major environmental concern due to their persistency and toxicity. Among them, mono-halogenated (HNs) and halomethyl naphthalenes (HMNs) are not well-studied, and the toxicity of many HNs to fishes has not been reported. In this study, we exposed zebrafish (Danio rerio) embryos to naphthalene and five HNs at concentrations ranging from 0.

View Article and Find Full Text PDF

Pyrethroid and organochlorine insecticides are enormously used to control agricultural and indoor insect pests. The metabolites of pyrethroid and endosulfan were used to evaluate environmental toxicities using a representative animal model, zebrafish (Danio rerio) embryos in this study. The LC values in 3-phenoxy benzoic acid (3-PBA) and endosulfan sulfate (ES) were 1461 μg/L and 1459 μg/L, respectively.

View Article and Find Full Text PDF

Toxicological studies of O-ethyl-O-(4-nitrophenyl) phenylphosphonothioate (EPN) to aquatic vertebrates have been reported, but no reports on toxic mechanism was reported. As zebrafish (Danio rerio) embryos were exposed to EPN, no changes in their survival and hatching rates were observed until 96 h post fertilization (hpf), even at the highest treated concentration of 500 μg/L. In both 250 μg/L and 500 μg/L, edemas were observed in the heart and yolk sac, and a blood pool was also found.

View Article and Find Full Text PDF

The increase in worldwide trade has caused the quality maintenance of commercialized agriproducts to be crucial in keeping its economic value. In recent years, methyl bromide (MB) has been used dominantly during quarantine and pre-shipment, despite it being an environmental hazard with global repercussions. Through this study, it was shown that Arabidopsis thaliana's 2 h exposure to the MB treatment displayed no signs of phytotoxicity, whereas its 4 h exposure significantly interfered with growth.

View Article and Find Full Text PDF

Melanogenesis represents a series of processes that produce melanin, a protective skin pigment (against ultraviolet rays), and determines human skin color. Chemicals reducing melanin production have always been in demand in the cosmetic market because of skincare interests, such as whitening. The main mechanism for inhibiting melanin production is the inhibition of tyrosinase (TYR), a key enzyme for melanogenesis.

View Article and Find Full Text PDF

Dimethyl sulfoxide (DMSO) is produced in nature and is known to be a source of carbon and sulfur for marine microorganisms. It is currently used in many biological experiments, pharmaceutical preparations, and energy-producing systems such as lithium batteries. Therefore, the toxicity of DMSO has been studied because of its various implications to living organisms; however, such studies are largely limited to measuring individual toxicity whereas the combined toxicity of DMSO with other compounds has rarely been investigated.

View Article and Find Full Text PDF

Azoxystrobin (AZ) and pyraclostrobin (PY) are strobilurin fungicides that inhibit fungal mitochondrial respiration. In this study, a representative model, zebrafish (Danio rerio), was used as a test species for acute and developmental toxicity. Survival and malformation rates were observed only PY-treated embryos, with an LC value of 77.

View Article and Find Full Text PDF

In this study, fluorene (FL), FL-1-carboxylic acid (FC-1), and FL-9-carboxylic acid (FC-9) were investigated to understand their acute toxicity by measuring inhibitory effects on hatching rates and developmental processes of zebrafish embryos (Danio rerio). For exposure concentrations up to 3000 μg/L, FC-1 alone showed acute toxicity at 1458 μg/L for LC value. FC-1 caused yolk sac and spinal deformities, and pericardial edema.

View Article and Find Full Text PDF

Endosulfan sulfate is a major oxidative metabolite of the chlorinated insecticide endosulfan. In this study, a targeted metabolomics approach was used to investigate the toxic mechanisms of endosulfan sulfate in adult zebrafish using the multiple reaction monitoring mode of a GC-MS/MS. The LC of endosulfan sulfate in adult zebrafish was determined and then zebrafish were exposed to endosulfan sulfate at one-tenth the LC (0.

View Article and Find Full Text PDF

Infestation of phosphine (PH) resistant insects threatens global grain reserves. PH fumigation controls rice weevil (Sitophilus oryzae) but not highly resistant insect pests. Here, we investigated naturally occurring strains of S.

View Article and Find Full Text PDF

This study assessed the developmental toxicities of water-soluble carbon black wastes (CBW) extract (1:5, w/v) in zebrafish embryos (Danio rerio). Acute embryonic toxicity was performed following OECD guideline 236. Analysis using ICP-OES revealed that nickel (Ni) and vanadium (V) were predominant in CBW.

View Article and Find Full Text PDF