• Journal of Korean Elementary Science Education
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• v.18 no.1
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• pp.75-85
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• 1999

This paper describes some major trends in primary and secondary education now. It is a selective views of significant topics with important implication for the future. These trends are summarized as follows, after examining historical development of Teaching-learning Methodology in primary and secondary education. 1. Education is seen as part of interdisciplinary world; emphasis is on relating education to the students' world, which is not compartmentalized. 2. Emphasizing students' individual growth with their own goal of lives. 3. Open-education with variable contents and purposes of education. 4. Education for all from that for some. 5. Consructivist based from behavior based. 6. Cooperative learning, peer tutoring, group projects. 7. Authentic assessment; assessment integrated with instruction. 8. The teacher is a facilitator of learning and a learner as well; students are learners and teachers in some situations; networks emerge instead of one-way forms or communication. 9. Spiral curriculum from single exposure.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.90.1-90.1
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• 2013

Nature utilizes various of the colorization process. Some species of birds can express their mood of tempers by changing their collagen structures on skin. For example, turkey can change their skin color by expansion of the collagen structures, which are associated with the distinct color changes. Here, we developed bioinspired virus-based colorimetric sensors which can be genetically tuned for target molecule. Using M 13 bacteriophage, we fabricated responsive self-assembled color matrices composed of quasi-ordered fiber bundle structures. These virus matrices can exhibit color change by stimuli through fiber bundle structure modulation. Upon exposure of volatile organic compounds, the resulting multi-colored matrices exhibited distinct color changes with different ratios that can be recognized by the naked eyes. Using the directed evolutionary approaches, we genetically engineered the virus matrix to incorporate binding motif for explosive detection (i.e., trinitrotoluene (TNT)). Through utilizing a common handheld device (i.e., iPhone), we could distinguish TNT molecules down to 20 ppb in a selective manner. Our novel biomimetic virus colorimetric sensor can overcome current limitation for low response selectivity.

• Clinical and Experimental Reproductive Medicine
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• v.8 no.2
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• pp.35-43
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• 1981

In order to evaluate the clinical utilization and efficacy of X-ray pelvimeter, a study of selective information from 292 cases, who had clinical and X-ray pelvimetry, among 7346 single term deliveries in the years 1975 and 1978 was undertaken in Yonsei University Medical Center. The results revealed that there were no significant statistical difference between X-ray and clinical pelvimetry groups in terms of the outcome of labor and in regard to determining the pelvic size (p > 0.05). Most X-ray examination which caused significant fetal exposure were pelvimetries.

• Mass Spectrometry Letters
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• v.10 no.1
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• pp.27-31
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• 2019

In this article, the properties of ${CO_2}^+(CO_2)_n$ clusters in a Paul ion trap have been investigated using mass-selective instability mode which conducted by chosen precursor ions, mainly $Ar^+$ and ${CO_2}^+$ produced by a mixture of Ar and $CO_2$. Exposure of ${CO_2}^+$ ions to $CO_2$ molecules, lead to the formation of ${CO_2}^+(CO_2)_n$ clusters. Here, Ar gas react as a buffer gas and lead to form ${CO_2}^+(CO_2)_n$ cluster by collisional effect.

• Molecules and Cells
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• v.27 no.5
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• pp.525-531
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• 2009

We studied the effect of carbachol on pacemaker currents in cultured interstitial cells of Cajal (ICC) from the mouse small intestine by muscarinic stimulation using a whole cell patch clamp technique and $Ca^{2+}$-imaging. ICC generated periodic pacemaker potentials in the current-clamp mode and generated spontaneous inward pacemaker currents at a holding potential of -70 mV. Exposure to carbachol depolarized the membrane and produced tonic inward pacemaker currents with a decrease in the frequency and amplitude of the pacemaker currents. The effects of carbachol were blocked by 1-dimethyl-4-diphenylacetoxypiperidinium, a muscarinic $M_3$ receptor antagonist, but not by methotramine, a muscarinic $M_2$ receptor antagonist. Intracellular $GDP-{\beta}-S$ suppressed the carbachol-induced effects. Carbachol-induced effects were blocked by external $Na^+$-free solution and by flufenamic acid, a non-selective cation channel blocker, and in the presence of thapsigargin, a $Ca^{2+}$-ATPase inhibitor in the endoplasmic reticulum. However, carbachol still produced tonic inward pacemaker currents with the removal of external $Ca^{2+}$. In recording of intracellular $Ca^{2+}$ concentrations using fluo 3-AM dye, carbachol increased intracellular $Ca^{2+}$ concentrations with increasing of $Ca^{2+}$ oscillations. These results suggest that carbachol modulates the pacemaker activity of ICC through the activation of non-selective cation channels via muscarinic $M_3$ receptors by a G-protein dependent intracellular $Ca^{2+}$ release mechanism.

• Korean Journal of Biological Psychiatry
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• v.4 no.2
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• pp.237-245
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• 1997

The study was designed to evaluate the significant roles of SSRI in rat of depression model. Chronic exposure to mild unpredictable stress has been found to depress the consumption of sweet 1% sucrose solutions in the Sprague-Dawley rats. We applied the variety of 11 types of stress regimens and identified depressive behaviours(developed by Willner) in 70 Sprague-Dawley rats. Rats in experiments were stratified into 6 groups, ie ; 3 kinds of SSRI(paroxetine, fluoxetine, sertraline), clomipramine, choline and saline control. Memory function was evaluated by passive avoidance learning and retention test. The authors determined how long memory retention would remain improved with 24 hour, 1 week, 2 weeks, 3 weeks, and 4 weeks at training-testing interval in depressive states of the Sprague-Dawley rats. The results were as follows ; 1) There were no significant differences between the 6 groups at the 24 hour training-testing interval. 2) The paroxetine treated group showed significant differences from the control group at the 1 week and 2 weeks training-testing interval. 3) The paroxetine and the fluoxetine treated groups showed singificant differences from the control group at 3 week training-testing interval. 4) The paroxetine and the choline treated groups showed significant differences from the control group at 4 week training-testing interval. In summary, paroxetine had an effect on long term memory processing from 1st week to 4th week. Also, fluoxetine(at 3rd week) and choline(at 4th week) had effect on long term memory processing. Sertraline, clomipramine were ineffective on memory processing during 4 weeks observation. Possible explanations why paroxetine had early effect on memory processing than the other selective serotonin reuptake inhibitors are rapid bioavailability, which is the characteristics of pharmacokinetics of paroxetine. In clinical situation, author carefully suggest that SSRI would be beneficial to improve the memory function caused by depressive neurochemical changes.

• Applied Microscopy
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• v.39 no.1
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• pp.17-25
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• 2009

This study investigated that exposure of male mice to estrogen receptor $\alpha$-selective agonist, 4,4',4"-(4-propyl-[1H]-pyrazole-1,3,5-triyl)tris-phenol (PPT) induce morphological changes of accessory genital glands. The male reproductive organs were fixed and processed for light microscopy. The PPT induced decreases of ventral prostates, seminal vesicles and preputial glands weights with experimental time. The glandular lumen of ventral prostate was atrophied compared with control group. Type of epithelial tissues in the prostate was changed from simple columnar epithelium to stratified cuboidal or squamous epithelium. Treated group with the agonist showed that increased connective tissue underlying epithelium in the prostate and seminal vesicle. Especially, the glandular lumen of the seminal vesicle was contracted when PPT-treated animals were compared with control group. Secretion cells of preputial gland were smaller than that of control group. On week 8, PPT treatment caused decrease of epithelial cell height lining the lumen of preputial gland. These results provide information useful in researching the physiological function of estrogen mediated by estrogen receptor $\alpha$ in male accessory genital gland.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.133-134
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• 2009

Cold temperature development (CTD) of electron beam (EB) patterned resists and subsequent dry etching were investigated for fabrication of nano-patterned Niobium (Nb). Bulky Nb fims on GaAs substrates were deposited with EB evaporation. Line patterns on Nb cathode were fabricated by EB patterning and reactive ion etching (RIE). Size deviations of nano-sized line patterns from CAD designed patterns are dependent on the EB total exposure, but it can be improved by CTD of EB-exposed resist. Line patterns of 10 to 300 nm widths of EB-exposed resist patterns were drawn under various exposure conditions of $0.2{\mu}s$/dot (total 240,000 dot) with a constant current (50 pA). Compared with room temperature development (RTD), the CTD improves pattern resolution due to the suppression of backscattering effect. RIE with $CF_4$ was performed for formation of several nano-sized line patterns on Nb. Each EB-resist patterned samples with RTDs and CTDs were etched with two different $CF_4$ gas pressures of 5 Pa. Nb etching rate increases while GaAs (or ZEP) etching rate decreases as the chamber pressure increases. This different dependent of the etching rate on the $CF_4$ pressure between Nb and GaAs (or ZEP) has a significant meaning because selective etching of nano-sized Nb line patterns is possible without etching of the underlying active layer.

• BMB Reports
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• v.39 no.4
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• pp.383-393
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• 2006

Little is known concerning the mechanisms responsible for the transplacental transfer of thiamine. So, the aim of this work was to characterize the placental uptake of thiamine from the maternal circulation, by determining the characteristics of $^3H$-thiamine uptake by a human trophoblast cell line (BeWo). Uptake of $^3H$-thiamine (50-100 nM) by BeWo cells was: 1) temperature-dependent and energy-independent; 2) pH-dependent (uptake increased as the extracellular medium pH decreased); 3) $Na^+$-dependent and $Cl^-$-independent; 4) not inhibited by the thiamine structural analogs amprolium, oxythiamine and thiamine pyrophosphate; 5) inhibited by the unrelated organic cations guanidine, N-methylnicotinamide, tetraethylammonium, clonidine and cimetidine; 6) inhibited by the organic cation serotonin, and by two selective inhibitors of the serotonin plasmalemmal transporter (hSERT), fluoxetine and desipramine. We conclude that $^3H$-thiamine uptake by BeWo cells seems to occur through a process distinct from thiamine transporter-1 (hThTr-1) and thiamine transporter-2 (hThTr-2). Rather, it seems to involve hSERT. Moreover, chronic (48 h) exposure of cells to caffeine ($1\;{\mu}M$) stimulated and chronic exposure to xanthohumol and iso-xanthohumol (1 and $0.1\;{\mu}M$, respectively) inhibited $^3H$-thiamine uptake, these effects being not mediated through modulation of the expression levels of either hThTr-1 or hSERT mRNA.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.4
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• pp.192-198
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• 2019

Objectives: Oral and maxillofacial surgeons must gain mastery of various approaches to the midface due to the increasing incidence, complexity, and severity of presenting midfacial fractures. Unlike in the case of other body parts, the need to preserve facial aesthetics makes it more difficult for the surgeon to select an approach for managing the facial injuries. The midfacial degloving (MFD) approach is a combination of intraoral and intranasal incisions made to access the midface without any external incision. The aim of the present study was to evaluate the efficacy of MFD in maxillofacial surgery and to assess its advantages and complications. Materials and Methods: The MFD approach was used in five cases, with three cases treated with open reduction and internal fixation and two cases operated on for posttraumatic deformity. Nasal dorsum augmentation was completed in three cases and nasal osteotomy was performed in one case. The bicoronal flap technique was combined with MFD for frontal bone augmentation in one case. The intraoperative time required for flap completion and the ease of performing the planned procedures were noted. Postoperative evaluation was done for reduction, aesthetics, function, and complications. Results: Access was excellent for performing all planned procedures. Average time spent for flap elevation and exposure of the midface was 63 minutes. Complications like postoperative swelling, infraorbital nerve paresthesia, and intranasal crusting were all transient. No long-term complications like stenosis of the nose, sneer deformity, or weakness of the facial muscles were noticed. Additionally, no complications were noted when MFD was combined with bicoronal flap. Conclusion: Though the MFD approach is technically demanding and takes more time than other facial approaches, it should be learned and applied by maxillofacial surgeons in selective cases, as it provides complete exposure of the midface without facial scarring.