• Journal of Environmental Science International
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• v.25 no.8
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• pp.1177-1189
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• 2016

In order to prepare the information needed to construct a reduction system for volatile organic compounds (VOCs) exhausted from ship-block paint-booths in a giant shipyard, VOCs in paint-shop airs were analyzed and compared to the components in paint thinners. Aromatic hydrocarbons containing eight and nine carbon atoms are known to be major VOC compounds found in shipyard paint-shops. The total hydrocarbon (THC(C7)) concentrations calibrated using toluene gas, were measured in block paint-shops with two photo-ionization detector (PID) meters, and the resulting THC(C7) data were converted to THC(C1) concentrations according to the Standard Methods for the Measurements of Air Pollution in South Korea. THC(C1) concentrations near the spray site ranged from 10 to 2,000 ppm, but they were less than 400 ppm near the walls of the paint-booth. The measurements of THC concentrations, based on the height of the monitoring sites, were related to the height of the target to which the spray paints were applied. The maximum concentrations occurred at almost the same height as the spray targets. When painted blocks had been dried-by warming with no spraying, the THC concentrations were 80~100 ppm.

• Toxicological Research
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• v.35 no.1
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• pp.65-74
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• 2019

Tetrahydrocurcumin (THC) is a major metabolite of curcumin, which is obtained from Curcuma longa. THC has various benefits and overcomes the bioavailability issue of curcumin. To establish it as a pharmacologically active molecule, its safety profile has to be determined. Thus, the present study aimed to determine the preclinical safety profile of THC in a 90-day subchronic and reproductive/developmental toxicity study in Wistar rats. THC at oral doses of 100, 200, and 400 mg/kg was administered daily for 90 days. Rats in the recovery group were kept for 14 days after treatment termination. The animals were observed for treatment-related morbidity, mortality, and changes in clinical signs, clinical pathology, and histopathology. In the reproductive/developmental toxicity study, THC at 100, 200, and 400 mg/kg was administered orally to rats and the reproductive/developmental parameters in adult male and female rats and pups were observed. THC at up to 400 mg/kg/day of did not have any significant effect on all parameters in male and female rats in both toxicity studies. Thus, 400 mg/kg/day can be considered as the no-observed-adverse-effect-level of THC in rats.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.2
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• pp.107-112
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• 2012

Although various derivatives of caffeic acid have been reported to possess a wide variety of biological activities such as neuronal protection against excitotoxicity and anti-inflammatory property, the biological activity of 3,4,5-trihydroxycinnamic acid (THC), a derivative of hydroxycinnamic acids, has not been clearly examined. The objective of the present study is to evaluate the anti-inflammatory effects of THC on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. THC significantly suppressed LPS-induced excessive production of nitric oxide (NO) and expression of iNOS, which is responsible for the production of iNOS. THC also suppressed LPS-induced overproduction of pro-inflammatory cytokines such as IL-$1{\beta}$and TNF-${\alpha}$ in BV2 microgilal cells. Furthermore, THC significantly suppressed LPS-induced degradation of $I{\kappa}B$, which retains NF-${\kappa}B$ in the cytoplasm. Therefore, THC attenuated nuclear translocation of NF-${\kappa}B$, a major pro-inflammatory transcription factor. Taken together, the present study for the first time demonstrates that THC exhibits antiinflammatory activity through the suppression of NF-${\kappa}B$ transcriptional activation in LPS-stimulated BV2 microglial cells.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.4
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• pp.449-452
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• 2010

In this article, the performance of the THC analyzer was inspected using two different span gases of methane ($CH_4$) and propane ($C_3H_8$). To explore the effect of standard gas selection, MicroFID system was tested by the following procedures. Initially, the system is spanned by propane gas of 60 ppm (or 180 ppmC). The system is then run against methane standards prepared at 5 different concentrations of 200, 250, 300, 400, and 500 ppm. According to the suggestion of the KMOE's test procedure to use multiplying a factor of 3 (for propane), the resulting THC values derived by methane standards were systematically biased with ~500% error relative to true value. This paper discusses the interpretation procedures to obtain the least biased THC values for a given span set-up.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.121-121
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• 2022

마자인(麻子仁)은 뽕나무과에 속하는 대마(Cannabis sativa L.)의 종자로써, 治血虛津虧, 腸燥便秘하며, 中風汗出, 逐水, 利小便, 破積血, 復血脈, 乳婦産後餘疾, 長髮 등에 사용한다고 기록되어 있다. 마자인 종자의 외피에는 환각성분인 Tetrahydrocannabinol (THC) 및 뇌전증과 다발성경화증 등 희귀, 난치성 질환의 치료제로 사용되는 Cannabidiol (CBD) 성분이 함유되어 있다. 따라서 외피를 제거한 마자인은 햄프씨드(Hemp Seed)로써 식품으로 이용되지만, 외피를 제거하지 않은 마자인은 의약품으로써 사용이 되고 있다. 마자인은 윤조탕, 자윤환, 마자인환 등 다양한 한의학 처방에 사용되지만, 외피에 함유되어있는 THC 및 CBD의 함유량 및 안전성에 대한 연구는 밝혀지지 않았다. 이에 마자인 함유처방의 안전성을 입증하는 실험방법을 설계하였다. 우선 의약품으로 유통되는 마자인의 외피에 THC 및 CBD 성분이 있는지를 확인하기 위해 마자인을 다양한 용매별 (물, 헥산 등)로 추출한 후 LC/MS를 이용해 성분 유무를 확인한다. 또한, 마자인 함유 처방 (마자인환, 자윤환, 윤조탕 등)을 복용하였을 경우 혈중에 THC 및 CBD 성분이 있는지를 확인하는 방법으로 실험동물에 마자인 함유 /처방을 투여한 후 혈액을 채취한다. 마찬가지로 성분 유무를 측정하는 방법은 LC/MS를 이용해 확인한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.10-21
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• 2006

The aim in this study is to develop the combined EGR system with a non-thermal plasma reactor for reducing exhaust emissions and improving fuel economy in turbo intercooler ECU common-rail diesel engines. At the first step, in this paper, the characteristics of performance and $NO_x{\cdot}THC$ emissions under four kinds of engine loads are experimentally investigated by using a four-cycle, four-cylinder, direct injection type, water-cooled turbo intercooler ECU common-rail diesel engine with a combined plasma exhaust gas recirculation(EGR) system operating at three kinds of engine speeds. The EGR system is used to reduce $NO_x$ emissions, and the non-thermal plasma reactor and turbo intercooler system are used to reduce THC emissions. The plasma system is a flat-to-flat type reactor operated by a plasma power supply. The fuel is sprayed by pilot and main injections at the variable injection timing between BTDC $15^{\circ}$ and ATDC $1^{\circ}$ according to experimental conditions. It is found that the specific fuel consumption rate with EGR is increased, but the fuel economy is better than that of mechanical injection type diesel engine as compared with the same output. Results show that $NO_x$ emissions are decreased, but THC emissions are increased, as the EGR rate is elevated. $NO_x$ and THC emissions are also slightly decreased as the applied electrical voltage of the non-thermal plasma reactor is elevated. Thus one can conclude that the influence of EGR in $NO_x$ and THC emissions is larger than that of the non-thermal plasma reactor, but THC emissions are greatly influenced by the non-thermal plasma reactor as the EGR rate is elevated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.131-136
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• 2012

This paper investigated the combustion and exhaust gas characteristics of gasoline direct injection engines for various cooling water temperature. The engine-out nanoparticle emission number and size distribution were measured by a DMS-500 equipped upstream of the catalyst. A CLD-400 and an HFR-400 were equipped at the exhaust port to analyze the cyclic NOx and total hydrocarbon emission characteristics. The results showed that the nanoparticle emission number greatly increased at low coolant temperatures and that the exhaust mainly contained particulate matter of 5.10 nm. THC also increased under low temperature conditions because of fuel film on the combustion chamber. NOx emissions decreased under high temperature conditions because of the increase in internal exhaust gas recirculation. In conclusion, an engine management system control strategy for driving coolant temperature up rapidly is needed to reduce not only THC and NOx but also nanoparticle emissions.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.6
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• pp.479-506
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• 2021

Background: Chronic neuropathic pain (NP) presents therapeutic challenges. Interest in the use of cannabis-based medications has outpaced the knowledge of its efficacy and safety in treating NP. The objective of this review was to evaluate the effectiveness of cannabis-based medications in individuals with chronic NP. Methods: Randomized placebo-controlled trials using tetrahydrocannabinol (THC), cannabidiol (CBD), cannabidivarin (CBDV), or synthetic cannabinoids for NP treatment were included. The MEDLINE, Cochrane Library, EMBASE, and Web of Science databases were examined. The primary outcome was the NP intensity. The risk of bias analysis was based on the Cochrane handbook. Results: The search of databases up to 2/1/2021 yielded 379 records with 17 RCTs included (861 patients with NP). Meta-analysis showed that there was a significant reduction in pain intensity for THC/CBD by -6.624 units (P < .001), THC by -8.681 units (P < .001), and dronabinol by -6.0 units (P = .008) compared to placebo on a 0-100 scale. CBD, CBDV, and CT-3 showed no significant differences. Patients taking THC/CBD were 1.756 times more likely to achieve a 30% reduction in pain (P = .008) and 1.422 times more likely to achieve a 50% reduction (P = .37) than placebo. Patients receiving THC had a 21% higher improvement in pain intensity (P = .005) and were 1.855 times more likely to achieve a 30% reduction in pain than placebo (P < .001). Conclusion: Although THC and THC/CBD interventions provided a significant improvement in pain intensity and were more likely to provide a 30% reduction in pain, the evidence was of moderate-to-low quality. Further research is needed for CBD, dronabinol, CT-3, and CBDV.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2017.10a
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• pp.90-90
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• 2017

• Atmosphere
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• v.15 no.1
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• pp.69-74
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• 2005

In this short article, oceanic processes that could have strong effect on the climate have been explained while focusing on the oceanic thermohaline circulation (THC). First, the structure of THC is explained using a simple scaling law. Then, the thermohaline catastrophe, which is believed to be a cause of a rapid climate changes observed in paleoclimate records, and interdecadal variations in THC are explained. The interactions between the oceans and $CO_2$ are also mentioned briefly.