• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.411-419
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• 2022

This study conducted acute oral toxicity test and acute dermal toxicity test to evaluate the toxicity of lightweight and high-strength cement composite containing carbon nanotube. It was compared with the toxicity of ordinary concrete that did not contain carbon nanotube. Both lightweight and high-strength cement composite and ordinary concrete were categorized in GHS category 5 as a result of acute oral toxicity test. In addition, no toxic symproms were observed during the acute dermal toxicity test in all specimens, concluding that those were judged to correspond to GHS category 5/unclassified.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1245-1258
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• 2022

This study was conducted to determine the effect of natural ingredient seasoning on the reduction of heterocyclic amine (HCA) production that may occur when pork belly is cooked at a very high temperature for a long time. Pork belly seasoned with natural ingredients, such as natural spices, blackcurrant, and gochujang, was cooked using the most common cooking methods, such as boiling, pan fry, and barbecue. HCAs in pork belly were extracted through solid-phase extraction and analyzed via high-performance liquid chromatography. For short-term toxicity, a mouse model was used to analyze weight, feed intake, organ weight, and length; hematology and serology analysis were also performed. Results revealed that HCAs formed only when heating was performed at a very high temperature for a long time, not under general cooking conditions. Although the toxicity levels were not dangerous, the method showing the relatively highest toxicity among various cooking methods was barbecue, and the natural material with the highest toxicity reduction effect was blackcurrant. Furthermore, seasoning pork belly with natural materials containing a large amount of antioxidants, such as vitamin C, can reduce the production of toxic substances, such as HCAs, even if pork belly is heated to high temperatures.

• The Korea Journal of Herbology
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• v.35 no.2
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• pp.1-6
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• 2020

Objectives : Heating process is the traditional processing method that has been applied to reduce the toxicity of dried resin of Toxicodendron vernicifluum (Anacardiacea) used as Geon-chil (乾漆, Lacca Rhois Exsiccata or Toxicodendri Resina). Urushiol, which is found in the plants of Toxicodendron genus, is a toxic compound that is absorbed into the skin and induces allergic dermatitis by being contacted. Hence, the reduction of urushiol level by heating processing of Geon-chil is crucial method for its medicinal application. Methods : Due to lack of Geon-chil processing-related articles, the articles researching the processing of lacquer (漆), as a coating material, were collected and analyzed to investigate the chemical change of urushiol during heating process. Results : The results demonstrate that the resin which was collected from the sap of T. vernicifluum tree was dried under warm and humid conditions repeatedly. During primary drying process, the laccase, a copper-containing enzyme in the resin, participated in the formation of urushiol polymers and thereafter urushiol-related toxicity could be reduced by making a lacquer harder and more stable. Moreover, heating a lacquer over 200℃ could cause thermo-degradation of urushiol polymers, and vaporized thermally degraded urushiol monomers and their by-products, which were determined using pyrolysis/GC-MS. Conclusions : These results support that heating process being performed over 200 ℃, such as stir-frying (炒) or calcination (煅), reduces the urushiol content in Geon-chil and hence, its medicinal use can be more stable without urushiol-related allergic reactions.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.1
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• pp.31-38
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• 2023

Carboplatin, an advanced anticancer drug with excellent efficacy against ovarian cancer, was developed to alleviate the side effects that often occur with cisplatin and other platinum-based compounds. Our study reports the in vitro characteristics, viability, and activity of cells expressing the inducible nitric oxide synthase (iNOS) gene after carboplatin was conjugated with polysuccinimide (PSI) and administered in combination with other widely used anticancer drugs. PSI, which has promising properties as a drug delivery material, could provide a platform for prolonging carboplatin release, regulating its dosage, and improving its side effects. The iNOS gene has been shown to play an important role in both cancer cell survival and inhibition. Herein, we synthesized a PSI-carboplatin conjugate to create a modified anticancer agent and confirmed its successful conjugation. To ensure its solubility in water, we further modified the structure of the PSI-carboplatin conjugate with 2-aminoethanol groups. To validate its biological characteristics, the ovarian cancer cell line SKOV-3 and normal ovarian Chinese hamster ovary cells were treated with the PSI-carboplatin conjugate alone and in combination with paclitaxel and topotecan, both of which are used in conventional chemotherapy. Notably, PSI-carboplatin conjugation can be used to predict changes in the genes involved in cancer growth and inhibition. In conclusion, combination treatment with the newly synthesized polymer-carboplatin conjugate and paclitaxel displayed anticancer activity against ovarian cancer cells but was not toxic to normal ovarian cancer cells, resulting in the development of an effective candidate anticancer drug without severe side effects.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.1003-1013
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• 2021

Thioredoxin (TRX) protein is an antioxidant responsible for reducing other proteins by exchanging cysteine thiol-disulfide and is also known for its anti-allergic and anti-aging properties. On the other hand, epidermal growth factor (EGF) is an important material used in the cosmetics industry and an essential protein necessary for dermal wound healing facilitated by the proliferation and migration of keratinocytes. EGF also assists in the formation of granulation tissues and stimulates the motility of fibroblasts. Hence, genetically modified soybeans were developed to overexpress these industrially important proteins for mass production. A single-dose oral-toxicity-based study was conducted to evaluate the potential toxic effects of TRX and EGF proteins, as safety assessments are necessary for the commercial use of seed-specific protein-expressing transgenic soybeans. To achieve this rationale, TRX and EGF proteins were mass purified from recombinant E. coli. The single-dose oral-toxicity tests of the TRX and EGF proteins were carried out in six-week old male and female Institute of Cancer Research (ICR) mice. The initial evaluation of the single-dose TRF and EGF treatments was based on monitoring the toxicity signatures and mortality rates among the mice, and the resultant mortality rates did not show any specific clinical symptoms related to the proteins. Furthermore, no significant differences were observed in the weights between the treatment and control groups of male and female ICR mice. After 14 days of treatment, no differences were observed in the autopsy reports between the various treatment and control groups. These results suggest that the minimum lethal dose of TRX and EGF proteins is higher than the allowed 2,000 mg·kg^-1 limit.

• Advances in nano research
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• v.14 no.6
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• pp.507-519
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• 2023

Postsurgical infections are caused by implant-related pathogenic microorganisms that lead to graft rejection. Hence, an intrinsically antibacterial material is required to produce a biocompatible biomaterial with osteogenic properties that could address this major issue. Hence, this current research aims to make strontium-doped hydroxyapatite nanorods (SrHANRs) via an ethylene diamine tetraacetic acid (EDTA)-enable microwave mediated method using Anodontia alba seashells for biomedical applications. This investigation also perceives that EDTA acts as a soft template to accomplish Sr-doping and mesoporous structures in pure hydroxyapatite nanorods (HANRs). The X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis reveals the crystalline and mesoporous structures, and Brunauer-Emmett-Teller (BET) indicates the surface area of all the samples, including pure HANRs and doped HANRs. In addition, the biocidal ability was tested using various implant-related infectious bacteria pathogens, and it was discovered that Sr-doped HANRs have excellent biocidal properties. Furthermore, toxicity evaluation using zebrafish reports the non-toxic nature of the produced HANRs. Incorporating Sr²⁺ ions into the HAp lattice would enhance biocompatibility, biocidal activity, and osteoconductive properties. As a result, the biocompatible HANRs materials synthesized with Sr-dopants may be effective in bone regeneration and antibacterial in-built implant applications.

• Advances in materials Research
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• v.13 no.3
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• pp.211-220
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• 2024

Polylactic acid or polylactide (PLA) is a biodegradable thermoplastic that can be produced from renewable material to create various components for industrial purposes. In 3D printing technology, PLA is used due to its good mechanical, electrical, printing properties, environmentally friendly and non-toxic properties. However, the physical properties and excellent electrical insulation properties of PLA have limited its application. In this study, with the carbon black (CB) as filler added into PLA, the lattice spacing and morphology were investigated by using X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The physical properties of PLA-carbon composite were evaluated by using tensile test, shore D hardness test and density and voids measurement. Impedance test was conducted to investigate the electrical properties of PLA-Carbon composites. The results demonstrate that the inclusion of carbon black as filler enhances the physical properties of the PLA-carbon composites, including tensile properties, hardness, and density. The addition of carbon black also leads to improved electrical conductivity of the composites. Better enhancement toward the electrical properties of PLA-carbon composites is observed with 1wt% of carbon black in N774 grade. The N550 grade with 2wt% of carbon black shows better improvement in the physical properties of PLA-carbon composites, achieving 10.686 MPa in tensile testing, 43.330 in shore D hardness test, and a density of 1.200 g/cm3 in density measurement. The findings suggest that PLA-carbon composites have the potential for enhanced performance in various industrial applications, particularly in sectors requiring improved physical and electrical properties.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.949-957
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• 2024

There has been a growing interest in skin beauty and antimelanogenic products. Melanogenesis is the process of melanin synthesis whereby melanocytes are activated by UV light or hormone stimulation to produce melanin. Melanogenesis is mediated by several enzymes, such as tyrosinase (TYR), microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TRP-1), and TRP-2. In this study, we investigated the effect of Tuber himalayense extract on melanin synthesis in α-melanocyte-stimulating hormone (α-MSH)-treated B16F10 melanoma cells. We confirmed that T. himalayense extract was not toxic to α-MSH-treated B16F10 melanoma cells and exhibited a significant inhibitory effect on melanin synthesis at concentrations of 25, 50, and 100 ㎍/ml. Additionally, the T. himalayense extract inhibited melanin, TRP-1, TRP-2, tyrosinase, and MITF, which are enzymes involved in melanin synthesis, in a concentration-dependent manner. Furthermore, T. himalayense extract inhibited the mitogen-activated protein kinase (MAPK) pathways, such as extracellular signal-regulated kinase-1/2 (ERK), c-Jun N-terminal kinase (JNK), and p38. Therefore, we hypothesized that various components of T. himalayense extract affect multiple factors involved in melanogenesis in B16F10 cells. Our results indicate that T. himalayense extract could potentially be used as a new material for preparing whitening cosmetics.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.473-477
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• 2013

This study was performed to evaluate the acute contact and oral toxicity of plant extracts (neem, sophora and derris) against Honeybee (Apis mellifera L.). As a result of acute contact toxicity test, $LD_{50}$ of neem and derris extracts were more than 100 ${\mu}g/bee$ while $LD_{50}$ of sophora extracts were 1.7 ${\mu}g/bee$. In case of acute oral toxicity test, $LD_{50}$ of neem and derris extracts were more than 100 ${\mu}g/bee$ while $LD_{50}$ of sophora extracts were 1.7 and 0.3 ${\mu}g/bee$. In conclusion, it is evaluated that neem and derris extracts are practically nontoxic while sophora extracts are highly toxic.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.397-401
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• 2016

A new solid oxidizer, pyridinium dinitramide (Py-DN) is a low toxic energetic material which can be utilized as a HPGP (high performance green propellant). In this work, Py-DN was synthesized using various starting materials including potassium sulfamate, pyridine hydrochloride, strong nitric acid and sulfuric acid. Physical and chemical properties of the Py-DN were characterized using UV-Vis, FT-IR and a thermal analyzer and their properties were compared to those of previously prepared salts including ammonium dinitramide[ADN, $NH_4N(NO_2)_2$] and guanidine dinitramide[GDN, $NH_2C(NH_2)NH_2N(NO_2)_2$] in our lab. Endothermic and exothermic decomposition temperatures of Py-DN were $77.4^{\circ}C$ and $144.7^{\circ}C$, respectively. The combustion caloric value was 1739 J/g, which is thermally more sensitive than that of conventional dinitramides. It may enable to lower the decomposition temperature, which can reduce preheating temperature required for satellite thruster applications.