• Natural Product Sciences
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• 제26권4호
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• pp.340-344
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• 2020

A new chromone analogue (1) was isolated from an EtOAc-extract of Pleosporales sp. culture medium, together with five known chromones (2 - 6). The isolation workflow was guided by a Molecular Networking-based dereplication strategy. The chemical structure of the new compound was elucidated using NMR and MS spectroscopy, and the absolute configuration was established by the Mosher's method. All isolated compounds were evaluated for their inhibitory effects on lipopolysaccharide-induced nitirc oxide production in RAW 264.7 macrophages. Compound 1 showed marginal inhibitory activity with an IC50 value of 118.7 μM.

• Archives of Pharmacal Research
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• 제23권1호
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• pp.54-58
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• 2000

To elucidate the molecular mechanisms for the suppression of LPS-induced nitric oxide (NO) production by a dehydrocostus lactone (DL) from Saussurea lappa, we examined the preventive effect of this compound on $NF-{\kappa}B$ activation in LPS-treated RAW 264.7 macrophages and U937 human monocytic cells. The results suggest that the suppression of NO production is mediated by the inhibitory action on the i-NOS gene expression through the inactivation of $NF-{\kappa}B$ and this sesquiterpene lactone can act as a pharmacological inhibitor of the $NF-{\kappa}B$ activation.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3299-3302
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• 2014

The In2S3 thin films of tetragonal structure and In2O3 films of cubic structure were synthesized by a spin coating method from the organometallic compound precursor triethylammonium indium thioacetate ($[(Et)_3NH]^+[In(SCOCH_3)_4]^-$; TEA-InTAA). In order to determine the electron mobility of the spin-coated TEA-InTAA films, thin film transistors (TFTs) with an inverted structure using a gate dielectric of thermal oxide ($SiO_2$) was fabricated. These devices exhibited n-channel TFT characteristics with a field-effect electron mobility of $10.1cm^2V^{-1}s^{-1}$ at a curing temperature of $500^{\circ}C$, indicating that the semiconducting thin film material is applicable for use in low-cost, solution-processed printable electronics.

• Journal of Information Display
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• 제10권4호
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• pp.171-174
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• 2009

The optical and electrical properties of the amorphous indium gallium zinc oxide thin-film transistor ($\alpha$-IGZO TFT) were studied. When the $\alpha$-IGZO TFT was illuminated at a wavelength of 660 nm, the off-state drain current slightly increased, while below 550 nm it increased significantly. The $\alpha$-IGZO TFT was found to be extremely sensitive, with deep-level defects at approximately 2.25 eV near the midgap. After UV light illumination, a slight change occurred on the surface of the $\alpha$-IGZO films, such as in terms of the oxygen 1s spectra, resistivity, and carrier concentrations. It is believed that these results will provide information regarding the photo-induced behaviors in the $\alpha$-IGZO films.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.531-533
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• 2009

We've studied the optical and electrical properties of amorphous indium gallium zinc oxide thin-film transistor (a-IGZO TFT). When the a-IGZO TFT was illuminated at a wavelength of 660 nm, the offstate drain current was slightly increased, while below 550 nm it was increased significantly. The a-IGZO TFT was extremely sensitive, with deep-level defects at approximately 2.25 eV near the midgap.

• 한국표면공학회지
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• 제34권2호
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• pp.142-150
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• 2001

Due to naturally formed copper oxides, the adhesion strength between copper and epoxy resin is often very poor. To improve the adhesion strength between copper and epoxy resin, Cu-based leadframe sheets were oxidized in a brown-oxide forming solution. Then the effect of brown-oxide formation on the adhesion strength of leadframe to epoxy molding compound (EMC) was studied using pull-out specimens. After the pull-out test, fracture surfaces were analyzed using SEM, AES and EDS to determine failure path. The results showed that the failure path lay over inside the CuO and inside the EMC irrespective of the pull strength.

• 약학회지
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• 제50권6호
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• pp.367-371
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• 2006

Phellinus pini (Hymenocaetaceae) has been used for the immunomodulating activity hypolipidemic effect, gastric cancer non-insulin dependant diabetes, diarrhea, and menstrual irregularity. From the screening of each fraction for the inhibitory activity of NO production in lipopolysaccaride (LPS) activated RAW 264.7 cells, methanol extract of Phellinus pini and hexane soluble fraction exhibited inhibition of NO production compared with LPS control without toxicity. The hexane soluble fraction showed dose dependent inhibition of NO production. According to activity guided fractionation, the active hexane fr. was repeatedly chromatographed over silica gel, ergosta-4,6,8(14),22- tetraen-3-one was isolated. The compound inhibited NOS activation (IC$_{50}$ = 29.7 uM) and NO production of activated macrophage at 30 uM.

• 한국안전학회지
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• 제38권2호
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• pp.30-35
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• 2023

Acetone is a widely used Volatile Organic Compound (VOC) in industries and laboratories. However, acetone affects human health adversely and causes fires and explosions. Early acetone detection and improved personnel training in safety and emergency management are necessary to prevent acetone-related accidents. The multi-VOC acetone detectors used currently have a sensitivity and selectivity limit. In this study, we discovered that Pt-loaded iron oxide (a metal oxide semiconductor) conversely, has high detection and selectivity for very low-levels of acetone gas. The loaded Pt catalyzes the reaction between the sensing materials' surface and the oxygen molecules in the air; this optimizes acetone detection and can decrease acetone-related illnesses, fires and explosions.

• 한국환경농학회지
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• 제10권2호
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• pp.167-177
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• 1991

O,S-dialkyl alkylphosphonothioates 계열 유기인제 농약의 체내 작용기작을 이해하기 위하여 model 화합물 (1), O-ethyl S-methyl ethylphosphonothioate [$LD_{50}$(rat, oral) 4.6mg/kg ; $K_i$(bovine erythrocyte acetylcholinesterase) 303 $M^{-1}min^{-1}$]이 선정되었다. 이 유기인계 화합물들은 체내에서 활성화(活性化) 과정을 겪으면서 독성(毒性)을 발현하는 것으로 가설(假說)되어져 왔다. 생체 내 mixed function oxidases에 의한 산화 활성화 과정을 화학적(化學的)으로 재현하기 위하여 두 종류의 유기산화제 즉, meta-chloroperoxybenzoic acid와 monoperoxyphthalic acid가 사용되었고, 대사적(代謝的) 산화를 재현하기 위하여 쥐 간(肝)에서 추출한 microsomal oxidation system을 이용한 in vitro 산화반응이 시도되었다. 산화반응 중간생성물인 S-oxide의 존재가 전구물질(1)의 가설적 산화 반응경로를 통해서 간접적으로나마 충분히 확인 되어질 수 있었다. 더욱이 ethanol을 이용한 trapping 실험에서 불안정한 산화중간물질인 S-oxide가 강한 phosphorylating agent라는 것이 확인되어, 전구물질 (1)로부터 산화반응을 거치면서 생성된 이 중간물질이 체내 신경전달에 중요한 역할을 하는 acetylcholinesterase를 phosphorylation하게 되고, 결국 이런 활성화 과정을 통해 이 계열의 화합물들이 독성을 발휘하는 것으로 이해될 수 있었다.

• 대한치과보철학회지
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• 제28권2호
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• pp.91-108
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• 1990

The purpose of this study was to compare the maganitude of the discrepancies of the mounting errors in according to the states of dentitions, and to the superoinferior, anteroposterior, and rightleft driecetions. GROUP I. : Fourteen patients 22 to 26 years of age with a full complement of teeth, were used in the study. The criteria fro patient selection were a complete dentition, sparse restorarive treatment, and adequate posterior and anterior occlusan stops. And they had no sign and sympton at TMG area. GROUPII. : Eigth patients 37 to 62 years of age with bilateral free ends. The criteria for patient selection were Kennedy classification class 1 cases, and adequate posterior and anterior stops. And the opposite dentitions were a full complement of teeth. Irreversible hydrocolloid impresiion of each arch was taken of each patient. These were immediatel poured in stone and mounted on a Denar Mark II. Articulator with the arbitrary slidematic face-bow. With hand articulation th e mandibular cast was mounted to the maxillary cast in centric occlusion. Five types of interocclusal records were taken of each patient : (1) aluwax (2) baseplate wax; (3) znic oxide-eugenol pasts; (4) polyether (Ramitec); (5) modeling compound. All measurement of the five selected recording materials were compared with those of the hand-articulated full arch models in centric occlusion or maximum interdigitation. The results were as follows; 1. There were statistical differences in amount of devitation in according to the materials and the states of dentition. The amount of deviation of compound was the largest. 2. There were statistical differences in amount of deviation in complete dentition at all directions. The amount of diviation of compound was the largest. And at the right-left direction the amount of znic oxide-eugenol paste was larger than that of baseplate wax. 3. There was a statistical difference in amount of diviations in partial edentulous dentition at the superoinferior direction. The amount of deviation of compound was larger than that of znic oxide-eugenol paste. 4. There was as statistical difference in amount of deviations in partial edentulous dentition at the right-left direction. The amount of deviation of baseplate wax was larger that tnat of polyether. 5. There was not a statistical difference in amount of diviation in partial edentulous dentition at the anteroposterior direction.