• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.272-277
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• 2001

Objective : Polymethylmethacrylate(PMMA) is often used to reconstruct the spine after total corpectomy, but the exothermic curing of liquid PMMA poses a risk of thermal injury to the spinal cord. The purposes of this study are to analyze the heat blocking effect of pre-polymerized PMMA sheet in the corpectomy model and to establish the minimal thickness of PMMA sheet to protect the spinal cord from the thermal injury during PMMA cementation of vertebral body. Materials & Methods : An experimental fixture was fabricated with dimensions similar to those of a T12 corpectomy defect. Sixty milliliters of liquid PMMA were poured into the fixture, and temperature recordings were obtained at the center of the curing PMMA mass and on the undersurface(representing the spinal cord surface) of a prepolymerized PMMA sheet of variable thickness(group 1 : 0mm, group 2 : 5mm, or group 3 : 8mm). Six replicates were tested for each barrier thickness group. Results : Consistent temperatures($106.8{\pm}3.9^{\circ}C$) at center of the curing PMMA mass in eighteen experiments confirmed the reproducibility of the experimental fixture. Peak temperatures on the spinal cord surface were $47.3^{\circ}C$ in group 2, and $43.3^{\circ}C$ in group 3, compared with $60.0^{\circ}C$ in group 1(p<0.00005). So pre-polymerized PMMA provided statistically significant protection from heat transfer. The difference of peak temperature between theoretical and experimental value was less than 1%, while the predicted time was within 35% of experimental values. The data from the theoretical model indicate that a 10mm barrier of PMMA should protect the spinal cord from temperatures greater than $39^{\circ}C$(the threshold for thermal injury in the spinal cord). Conclusion : These results suggest that pre-polymerized PMMA sheet of 10mm thickness may protect the spinal cord from the thermal injury during PMMA reconstruction of vertebral body.

• Journal of the Korean GEO-environmental Society
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• v.16 no.4
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• pp.13-22
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• 2015

The combined impact of Dissolved Organic Matter (DOM) fouling and inorganic ($CaSO_4,Ca_3(PO_4)_2$) scaling on the retention of TNT (2, 4, 6-Trinitrotoluene), RDX (Hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine) and HMX (1, 3, 5, 7-Tetranitro-1, 3, 5, 7-tetrazocane) explosive contaminants by nano-filtration membrane were studied, since organic fouling and salt scaling are the major limitations for membrane filtration. Results reported here indicate that DOM fouling layer with a humic acid does not necessarily lead to an immediate loss of permeate flux but can result in a severe impact on the flux loss when both humic acid and inorganic scaltants were presented simultaneously. The $Ca_3(PO_4)_2$ mixed with humic acid showd most sever flux loss (42%) compared to that of only humic acid presence (8%). It could be a result that the scaling formation of the NF membrane was dominated by cake layer formation of DOM and it was along with pore blocking by the formation of crystals inside the porous active matrix of the NF membrane. In addition, these results indicated that the membrane selectivity of the explosives retention trended correlated with respect to increasing explosives size (listed by MW) based on greater steric interactions and followed the order (MW, g $mol^{-1}$; removal, %): HMX (296.15; 83%) ${\gg}$ RDX (222.12; 49%) ≋ TNT (227.13; 32%). Because the scaling and fouling layer could lead to a additional cake-enhanced concentration polarisation effect, the retention of explosives with the presence of humic acid in the feed solution and inorganic scaling formation on top of an organic fouling layer do not differ substantially retention from that of pure DI feed and NaCl solution.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.7
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• pp.37-43
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• 2008

In this paper, the dependence of electrical characteristics of Silicon-$Al_2O_3$-Nitride-Oxide-Silicon (SANOS) memory cell transistors and program/erase (P/E) speed, reliability of memory device on interface trap between Si substrate and tunneling oxide and bulk trap in nitride layer were investigated using charge pumping method which has advantage of simple and versatile technique. We analyzed different SANOS memory devices that were fabricated by the identical processing in a single lot except the deposition method of the charge trapping layer, nitride. In the case of P/E speed, it was shown that P/E speed is slower in the SANOS cell transistors with larger capture cross section and interface trap density by charge blocking effect, which is confirmed by simulation results. However, the data retention characteristics show much less dependence on interface trap. The data retention was deteriorated as increasing P/E cycling number but not coincides with interface trap increasing tendency. This result once again confirmed that interface trap independence on data retention. And the result on different program method shows that HCI program method more degraded by locally trapping. So, we know as a result of experiment that analysis the SANOS Flash memory characteristic using charge pumping method reflect the device performance related to interface and bulk trap.

• Journal of The Korean Association For Science Education
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• v.18 no.1
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• pp.61-70
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• 1998

This study investigated the effects of grouping (group composition) in cooperative learning strategy upon students' achievement, the attitude toward science instruction, the perception of learning environment, and the self-esteem. Three different groups were used in this study. For the two treatment groups with cooperative learning strategies, High-Medium-Low ability grouping (HML) and High-Low I Medium-Medium ability grouping (HL/MM) were used. For the control group, traditional instruction was used. Before the instructions, the short-version Group Assessment of Logical Thinking, the test of attitudes toward science instruction, the perception questionnaire of learning environment, and the questionnaire of self-esteem were administered, and their scores were used as covariates. Mid-term examination score was used as a blocking variable. After the instructions, a researcher-made achievement test consisting of three subtests (knowledge, understanding, and application), the test of attitude toward science instruction, the perception questionnaire of learning environment, and the questionnaire of self-esteem were administered. The ANCOVA results revealed that there were significant interactions between the instruction and the level of prior achievement although there were no significant differences in all subtest scores of the achievement test. The high-level students in the HL/MM cooperative group performed better than those in the control group and the HML cooperative group. The low-level students in the HL/MM cooperative group also performed better in the subtest of knowledge than those in the other groups. However, the medium-level students in the HML cooperative group scored better than those in the control group and the HL/MM cooperative group. Significant main effect was also found in the perception of learning environment but not in the attitude toward science instruction and self-esteem. The cooperative groups, regardless of grouping, exhibited more positive perception than the control group.

• Journal of Pharmaceutical Investigation
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• v.31 no.4
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• pp.289-295
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• 2001

Carvedilol is an antihypertensive and antianginal compound that combines nonselective beta-adrenoceptor blocking and vasodilation properties and is devoid of intrinsic sympathomimetic activity. The purpose of the present study was to evaluate the bioequivalence of two carvedilol tablets, $Dilatrend^{TM}$ (Chong Kun Dang Pharmaceutical Co., Ltd.) and $Carvelol^{TM}$ (Dae Won Pharmaceutical Co., Ltd.), according to the prior and revised guidelines of Korea Food and Drug Administration (KFDA). The carvedilol release from the two carvedilol tablets in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution, water and blend of PSB80 into water). Eighteen normal male volunteers, $24.22{\pm}1.86$ years in age and $64.81{\pm}4.56\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 25 mg of carvedilol was orally administered, blood was taken at predetermined time intervals and the concentrations of carvedilol in serum were determined using HPLC method with fluorescence detector. The dissolution profiles of two carvedilol tablets were very similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using non-transformed and logarithmically transformed $AUC_t$ and $C_{max}$. The results showed that the differences in $AUC_t$, $C_{max}$ and $T_{max}$ between two tablets based on the $Dilatrend^{TM}$ were 2.23%, -2.00% and 0.00%, respectively. Minimum detectable differences $({\Delta})$ at ${\alpha}=0.05$ and $1-{\beta}=0.8$ were less than 20% (e.g., 13.55% and 17.61% for $AUC_t$ and $C_{max}$, respectively). The powers $(l-{\beta})$ at ${\alpha}=0.05$, ${\Delta}=0.2$ for $AUC_t$ and $C_{max}$ were 98.08% and 88.81%, respectively. The 90% confidence intervals were within ${\pm}20%$ (e.g., $-5.69{\sim}10.16$ and $-12.30{\sim}8.30$ for $AUC_t$ and $C_{max}$, respectively). There were no sequence effect between two tablets in logarithmically transformed $AUC_t$ and $C_{max}$. The 90% confidence intervals using logarithmically transformed were within the acceptance range of log(0.8) to log(1.25) (e.g., $0.95{\sim}1.11$ and $0.89{\sim}1.09$ for $AUC_t$ and $C_{max}$, respectively). Two parameters met the criteria of prior and revised KFDA guideline for bioequivalence, indicating that $Carvelol^{TM}$ tablet is bioequivalent to $Dilatrend^{TM}$ tablet.

• Tuberculosis and Respiratory Diseases
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• v.54 no.1
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• pp.104-113
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• 2003

Background : Rhinovirus(RV) infections frequently trigger dyspnea and paroxysmal cough in adult patients with asthma and are the most prevalent cause of the common cold. However, the mechanisms of a RV-induced airway inflammation is unclear. Since the RV does not directly destroy the airway epithelium, it is presumed that the immune response to the RV contributes to the pathogenesis of the respiratory symptoms. In order to test this hypothesis, this study characterized the time-sequenced alterations in interleukin(IL)-8 elaboration from the human bronchial epithelial cells and evaluated the role of NF(nuclear factor)-${\kappa}B$ in the RV-induced IL-8 production by pretreating the inhibitors of NF-${\kappa}B$ activation. Methods : The ability of RV-infected human bronchial epithelial cells and BEAS-2B cells to produce the IL-8 was compared with the controls. This study infected BEAS-2B cells with the RV14 obtained from the American Type Culture Collection. The supernatants were harvested from the RV infected BEAS-2B cells and the controls at 2hr, 4hr, 6hr, 12hr, 24hr, 48hr from the inoculation time. This study measured the IL-8 concentration using the ELISA kits. In order to elucidate the role of NF-${\kappa}B$ in the RV-induced IL-8 production, the effect of the NF-${\kappa}B$ inhibitors was evaluated on RV-induced IL-8 production. Results: The BEAS-2B cells produced small amounts of IL-8 that accumulated slowly with time in the culture. The RV was a potent stimulator of the IL-8 proteins production by BEAS-2B human bronchial epithelial cells. Antioxidants, N-acetyl-L-cysteine(NAC),\ and pyrrolidine dithiocarbamate(PDTC), blocked the IL-8 elaboration by the RV-infected BEAS-2B cells, which was dose-dependent, but N-Tosyl-L-phenylalanine chloromethyl ketone(TPCK) did not. Conclusion: Some antioxidants inhibited the RV-induced IL-8 production by blocking the NF-${\kappa}B$, which may have a therapeutic potential in asthma.

• Journal of Haehwa Medicine
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• v.9 no.1
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• pp.547-594
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• 2000

I. Introduction The essence of Oriental medicine consists of ancient books, experienced doctors and succeeded skills of common society. Many famous doctors studied medical science by their fathers or teachers. So the history of medical science is long. $\ll$DangDaeMyeongIImJeungJeongHwa(當代名醫臨證精華)$\gg$ written by SaWoogWang(史宇廣) and DanSeoGeon(單書健) has many medical experience of famous doctors. So it has important historical value. Bi(痺) means blocking. BiJeung is one kind of symptoms making muscles, bones and jonts feel pain, numbness or edema. For example it can be gout or SLE etc. So I studied ${\ll}BiJeungJuJip{\gg}$. II. Final Decision Following decisions of Chinese doctors of 20th century are as follows ; 1. JuYangChun(朱良春) emphasized on IkSinJangDok(益腎壯督) to treat BiJeong. And he devided WanBi(頑痺) as PungHanSeup(風寒濕), DamEo(痰瘀), YeolDok(熱毒), SinHeo(腎虛). He used insects for medicine. 2. ChoSuDoek(焦樹德) introduced past prescription. He used ChiBiTang(治痺湯) to treat HaengBi(行痺), TongBi(痛痺), ChakBi(着痺). He insisted that Han(寒; coldness) and Seup(濕; dampness) be Eum(陰) and Pung(風; wind) can change his character to be Eum. After all BiJeung is usually EumJeung. So he used GaeJi(桂枝) and BuJa(附子). By the way he used ChungYeolSanBiTang(淸熱散痺湯) for YeolBi, BoSinGeoHanChiWangTang SaBok(王士福) emphasized on the importance of medicine. He introduced many treatments like CheongYeol(情熱) for YeolBi and YiO(二烏) for HanBi. And he divided BiJeung period for three steps. At 1st step, we must use GeoSa(祛邪), at 2nd step, we must use BuJeong(扶正) and at 3rd step, we must use BoHyeol(補血), he insisted. And he introduced many herbs to treat BiJeung. 4. JeongGwangJeok(丁光迪) said that GaeJi(桂枝), MaHwang(麻黃), OYak(烏蘖) and BuJa(附子) are very important for TongRak(通絡). And pain usually results from Han(寒), so he liked to use hot-character herbs. 5. MaGi(馬志) insisted that BiJeung usually result from ChilJeong(七情). And he liked to use insects for treatment of BiJeung. 6. WeolSeokMu(越錫武) introduced 8 kinds of treatments and divided BiJeung period. Also he divided BeJeung for PungBi(風痺), HanBi(寒痺) and SeupBi(濕痺). 7. SeoGeaHam(徐季含) observed many patients and concluded that 86.7% of BiJeung is HeuJeung(虛症). 8. YuJiMyeong(劉志明) said that YeolBi is important and CheongYeol is also important. So he emphasized on DangGyuiJeomTongTang(當歸拈痛湯) and SeonBiTang(宣痺湯). 9. WangLiChu(汪履秋) studied cause of WanBi. Internal cause is GiHyeolHeo(氣血虛) and GanSinHeo(肝腎虛) and external cause is SaGi(邪氣) he insisted. 10. WangSaSang(王士相) said that YeolBi can be SeupYeolBi or EumHeuYeolBi(陰虛熱痺) and HanSeupBi(寒濕痺) is rare. He use WooBangJaSan(牛蒡子散) and BangPungHwan(防風丸) for SeupYeolBi, DangGyuiSaYeokTang(當歸四逆湯) for HanSeupBi. 11. JinTaekGang(陳澤江) treated YeolBi with BaekHoGaGyeJiTang(自虎加桂枝湯) and SaMyoSan(四妙散). If they don't have effect, he tried to cure BiJeung step by step. And he used e term of GeunBi(筋痺) and BangGiMogwaEIInTang(防己木瓜薏苡仁湯) was good for GeunBi. 12. MaSeoJeong(麻瑞亭) said that PungSeupYeokJeul(風濕歷節) is BiJeung and it is related to GanBinSin(肝脾腎; liver, Spleen, Kindey). And he emphasized on balance WiGi(衛氣) and YoungHeul(營血). 13. SaJeJu(史濟桂) said that GeunGolBi(筋骨痺) is similar to arthritis and sometimes called ChakBi. And SinBi(腎痺) is terminal stage of ChakBi, he said. He also used insects for treatment. 14. JeongJeNam(丁濟南) tried to cure SLE and used GyeJi, CheonCho(川椒), SinGeunCho(伸筋草), SunRyeongBi(仙靈脾), HyconSam(玄蔘) and GamCho(甘草). 15. JinGYungHwa(陳景和) emphasized on diagnosis of tongue. If the color of tongue is blue, it usually has EoHyeol(瘀血), for example. And he also used insects. 16. JuSongI(朱松毅) tried to devide YeolBi with OnByeong(溫病), Wi(衛), Gi(氣) and Hyeol(血). 17. RuDaBong(蔞多峰) said that JyeongHeo(正虛), OiSa(外邪) and EoHyeol are closely related. And he explained BiJeung by deviding the body into the part, for example head, neck, shoulder, waist, upper limb and lower limb. 18. YuMuBo(劉茂甫) defined PungHanSyubBi as chronic stage and YeolBi as acute stage.

• Journal of Life Science
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• v.22 no.12
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• pp.1688-1696
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• 2012

Oenanthe javanica has been used as a food source and also in traditional folk medicine for its detoxifying properties and anti-microbial effects since ancient times. In this study, we evaluated the effect and mechanism of O. javanica seed methanol extract (OJSE) on adipocyte differentiation by 3T3-L1 preadipocytes. Under non-toxic conditions, OJSE treatment resulted in a dose-dependent inhibition of lipid droplet generation and triglyceride accumulation by suppressing adipocyte differentiation, which are associated with the decreased expression of key proadipogenic transcription factors including CCAAR/enhancer binding protein ${\alpha}$, ${\beta}$ ($C/EBP{\alpha}$, $C/EBP{\beta}$) and peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$). OJSE also significantly inhibited proliferation and differentiation of 3T3-L1 preadipocytes through G1-phase arrest, indicating that OJSE blocked mitotic clonal expansion during adipocyte differentiation. Investigation of the alteration of G1 phase arrest-related proteins indicated a dose-dependent increase in the expression of p21 and reduction in expression of cyclin E, Cdk2, E2F-1 and phospho-Rb by OSJE. Taken together, these results suggest that OJSE inhibits adipocyte differentiation by blocking the mitotic clonal expansion, which is accompanied by preadipocyte cell cycle arrest.

• Journal of Life Science
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• v.27 no.9
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• pp.1070-1077
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• 2017

Chondrocyte apoptosis induced by reactive oxygen species (ROS) plays an important role in the pathogenesis of osteoarthritis. Schisandrin A, a bioactive compound found in fruits of the Schisandra genus, has been reported to possess multiple pharmacological and therapeutic properties. Although several studies have described the antioxidant effects of analogues of schisandrin A, the underlying molecular mechanisms of this bioactive compound remain largely unresolved. The present study investigated the cytoprotective effect of schisandrin A against oxidative stress (hydrogen peroxide [$H_2O_2$]) in SW1353 human chondrocyte cells. The results showed that schisandrin A preconditioning significantly inhibited $H_2O_2-induced$ growth inhibition and apoptotic cell death by blocking the degradation of poly (ADP-ribose) polymerase proteins and down-regulating pro-caspase-3. These antiapoptotic effects of schisandrin A were associated with attenuation of mitochondrial dysfunction and normalization of expression changes of proapoptotic Bax and antiapoptotic Bcl-2 in $H_2O_2-stimulated$ SW1353 chondrocytes. Furthermore, schisandrin A effectively abrogated $H_2O_2-induced$ intracellular ROS accumulation and phosphorylation of histone H2AX at serine 139, a widely used marker of DNA damage. Thus, the present study demonstrates that schisandrin A provides protection against $H_2O_2-induced$ apoptosis and DNA damage in SW1353 chondrocytes, possibly by prevention of ROS generation. Collectively, our data indicate that schisandrin A has therapeutic potential in the treatment of oxidative disorders caused by overproduction of ROS.

• Journal of Life Science
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• v.31 no.11
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• pp.987-994
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• 2021

Our previous studies have reported that antimicrobial peptides (AMPs) derived from the larvae of white-spotted flower chafer (Protaetia brevitarsis seulensis) exert anti-inflammatory and neuroprotective activities. This study explored the anti-inflammatory effects of protaetiamycine 9 (CVLKKAYFLTNLKLRG-NH₂), a novel AMP, derived from P. b. seulensis against lipopolysaccharide (LPS)-mediated inflammatory response in RAW264.7 macrophage cells. Protaetiamycine 9 (25, 50, 75, and 100 ㎍/ml) did not cause cytotoxic effects against RAW264.7 cells. The RAW264.7 cells were pre-treated with various concentrations of protaetiamycine 9 (25-100 ㎍/ml) for 1 hr and then exposed to LPS (100 ng/ml) for 24 hr. Protaetiamycine 9 treatments decreased the LPS-induced secretion of inflammatory mediators, such as nitric oxide (NO), in a dose-dependent manner. Protaetiamycine 9 (25-100 ㎍/ml) effectively downregulated the LPS-induced increase in mRNA and the protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), which are involved in the production of inflammatory mediators. Protaetiamycine 9 also suppressed the production and gene expression of pro-inflammatory cytokines, including interleukin (IL)-6 and IL-1β, compared to the presence of LPS alone. Furthermore, protaetiamycine 9 inhibited the degradation of inhibitory kappa B alpha (IκB-α) and the phosphorylation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. In conclusion, these results suggest that protaetiamycine 9 exhibits LPS-mediated inflammatory responses by blocking IκB-α degradation and MAPK phosphorylation.