• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.250-250
• /
• 2012

Recently, multiferroic materials have attracted much attention due to their fascinating fundamental physical properties and potential technological applications in magnetic/ferroelectric data storage systems, quantum electromagnets, spintronics, and sensor devices. Among single-phase multiferroic materials, $BiFeO_3$, in particular, has received considerable attention because of its very interesting magnetoelectric properties for application to spintronics. Enhanced ferromagnetism was found by Fe-site ion substitution with magnetic ions. In this study, $BiFe_{1-x}Ni_xO_3$ (x=0 and 0.05) bulk ceramic compounds were prepared by solid-state reaction and rapid sintering. High-purity $Bi_2O_3$, $Fe_3O_4$ and NiO powders were mixed with the stoichiometric proportions, and calcined at $450^{\circ}C$ for 24 h to produce $BiFe_{1-x}Ni_xO_3$. Then, the samples were directly put into the oven, which was heated up to $800^{\circ}C$ and sintered in air for 20 min. The crystalline structure of samples was investigated at room temperature by using a Rigaku Miniflex powder diffractometer. The Raman measurements were carried out with a Raman spectrometer with 514.5-nm-excitation Ar+-laser source under air ambient condition on a focused area of $1-{\mu}m$ diameter. The field-dependent magnetization and the temperature-dependent magnetization measurements were performed with a vibrating-sample magnetometer. The x-ray diffraction study demonstrates the compressive stress due to Ni substitution at the Fe site. $BiFe_{0.95}Ni_{0.05}O_3$ exhibits the rhombohedral perovskite structure R3c, similar to $BiFeO_3$. The lattice constant of $BiFe_{0.95}Ni_{0.05}O_3$ is smaller than of $BiFeO_3$ because of the smaller ionic radius of Ni3+ than that of Fe3+. The field-dependent magnetization of $BiFe_{0.95}Ni_{0.05}O_3$ exhibits a clear hysteresis loop at 300 K. The magnetic properties of $BiFe_{0.95}Ni_{0.05}O_3$ were improved at room temperature because of the existence of structurally compressive stress.

• 대한두경부종양학회지
• /
• 제14권2호
• /
• pp.228-235
• /
• 1998

Objectives: Papillary microcarcinoma of the thyroid was evaluated as to the effectiveness of diagnostic modalities, lymphatic spread pattern, and therapeutic decision according to tumor size. Material and Methods: We retrospectively analyzed a clinicopathologic findings of 72 papillary microcarcinoma patients who were treated at the over 11 years between 1985 and 1995. The authors divided papillary microcarcinoma of the thyroid into two subgroups according to tumor size: $0{\leqq}5mm$ and $5<0{\leqq}10mm$. An analysis including age and gender distribution, diagnostic tools(thyroid sonogram, thyroid scan, thyroid function test, fine needle aspiration cytology, frozen section), pathological examination of lymphnode, and surgical procedures was carried out in each subgroups. Results: The carcinoma of smaller than 5mm were found in 32 patients, and of 6 -10mm were in 40 patients. The average age of patients was 45years and all of them were female. Cold nodules on thyroid scan were noticed in 53 patientss and normal findings were in 15 patients. Suspicious malignant lesions(fine calcification, solid mass, irregular margin) on thyroid sonography were detected in 23 patients and the sonography was more useful in detecting $0{\leqq}5mm$ small sized lesions than other diagnostic methods. FNAC were performed in 17 patients, and 7 patients were diagnosed as having thyroid papillary cancer. But diagnotic rate in $0{\leqq}5mm$ small sized lesions was very low(one of eights).Frozen section were performed in all patients, among these 15 patients were diagnosed as being benign diseases and false negative rates were higher in $0{\leqq}5mm$ small sized lesions than in $5<0{\leqq}10mm$ sized lesions(p-value<0.006). Only thyroidectomies were performed in 24 patients and thyroidectomy with node dissections in 48 patients. The lymphnode metastatic rates were much higher in multifocal lesions(61.5%) than in single lesion. The incidence of cervical lymphnode metastasis was 19.4% in $0{\leqq}5mm$ sized lesions and 47.9% in $5<0{\leqq}10mm$ sized lesions. Postoperative management were performed with TSH suppression therapy(T4, synthroid) in all patients and RI therapy in 29 patients. Conclusion: On the basis of our study, improved preoperative diagnostic tools for papillary microcarcinoma of the thyroid was helpful in the choice of surgical treatment. As a result of techninological progress(ultrasonography, FNAC), the pencentage of the discovery of papillary microcarcinoma has been increased. The thyroid ultrasonography was useful in detecting small sized lesions($0{\leqq}5mm$), but FNAC may not be beneficial in detecting small sized lesions($0{\leqq}5mm$). In the surgical procedure, thyroid lobectomy alone should be avoided because of the high rate of bilaterality and multifocality.

• 대한후두음성언어의학회지
• /
• 제26권2호
• /
• pp.117-121
• /
• 2015

Background : Cepstral analysis which is obtained from Fourier transformation of spectrum has been known to be effective indicator to analyze the voice disorder. To evaluate the voice disorder, phonation of sustained vowel /a/ sound or continuous speech have been used but the former was limited to capture hoarseness properly. This study is aimed to compare the effectiveness in analysis of cepstrum between the sustained vowel /a/ sound and continuous speech. Methods : From March 2012 to December 2014, total 72 patients was enrolled in this study, including 24 unilateral vocal cord palsy, vocal nodule and vocal polyp patients, respectively. The entire patient evaluated their voice quality by VHI (Voice Handicap Index) before and after treatment. Phonation of sustained vowel /a/ sample and continuous speech using the first sentence of autumn paragraph was subjected by cepstral analysis and compare the pre-treatment group and post-treatment group. Results : The measured values of pre and post treatment in CPP-a (cepstral peak prominence in /a/ vowel sound) was 13.80, 13.91 in vocal cord palsy, 16.62, 17.99 in vocal cord nodule, 14.19, 18.50 in vocal cord polyp respectively. Values of CPP-s (cepstral peak prominence in text-based speech) in pre and post treatment was 11.11, 12.09 in vocal cord palsy, 12.11, 14.09 in vocal cord nodule, 12.63, 14.17 in vocal cord polyp. All 72 patients showed subjective improvement in VHI after treatment. CPP-a showed statistical improvement only in vocal polyp group, but CPP-s showed statistical improvement in all three groups (p<0.05). Conclusion : In analysis of cepstrum, text-based analysis is more representative in voice disorder than vowel sound speech. So when the acoustic analysis of voice by cepstrum, both phonation of sustained vowel /a/ sound and text based speech should be performed to obtain more accurate result.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제33권2호
• /
• pp.124-130
• /
• 2007

In the present study, I investigated the effects of N-methyl-D-aspartate (NMDA), arachidonic acid (AA), and Nitric Oxide Synthase Inhibitor (NOSI), alone or in combination, on the proliferation of cultured primary normal human oral keratinocytes (NHOK). The purpose of this study was therefore the preliminary study for the examination of the interaction between these agents and NHOK in order to elucidate the mechanisms by which epithelial growth and regeneration are regulated. NHOK were obtained from gingival tissue of 20 individuals aged 20 to 29, and third passage (P3) cells were used for this study. The DNA synthesis was measured by the BrdU assay. Addition of low concentration of AA ($1{\mu}M$) and high concentration of AA with NMDA group (NMDA+AA $10{\mu}M$) made DNA synthesis rate increase significantly at the early stage. Adding NNA ($10{\mu}M$) affected DNA synthesis rate to increase significantly in 4 hours. At the early stage, DNA synthesis was significantly active in the NOS-I with NMDA groups than in the control and the NMDA-only group, while it didn't become statistically meaningful in 24 hours. AA $1{\mu}M$ and NNA $10{\mu}M$ may induce the proliferation of the NHOK independently and NOS-I may induce the proliferation of the NHOK with NMDA. These reactions might be related to the NMDA receptor in the cell and the change of the intracellular calcium ion concentration.

• 한국과학교육학회지
• /
• 제24권5호
• /
• pp.805-813
• /
• 2004

현재의 교육과정은 좌반구 중심의 활동으로 주로 이루어지고 있어 우반구 중심으로 사고하는 학생들은 학습에 어려움을 많이 느끼고 있다. 따라서 우뇌 우세 학생 집단에서 학습부진아가 많이 나타난다. 특히, 과학은 좌반구 중심의 사고가 많이 요구되는 과목으로 우뇌 우세 학생들이 흥미를 잃기 쉽고 학업성취도도 낮다. 본 연구에서는 좌뇌 중심의 과학 학습에서 소외되기 쉬운 우뇌 우세 학생들의 학업성취도를 향상시킬 수 방법으로 좌 우뇌 요소를 고루 활용하는 마인드 맵을 적용하여 마인드 맵을 활용한 수업이 학생들의 과학 학업성취도 향상에 효과적인지 알아보았다. 그리고 뇌 기능 분화와 성별에 따라서 수업의 효과 차이가 있는지 분석하였다. 본 연구의 대상은 중학교 1학년 학생 158명으로, 통제반은 전통적인 수업을 하였고, 실험반은 마인드 맵을 활용한 수업을 실시하였다. 연구 단원은 "생물의 구성", "상태변화와 에너지", "소화와 순환", "호흡"단원으로 약 17주간 50차시에 걸쳐 수업 처치를 하였다. 학생들의 뇌 기능 분화는 SOLAT 검사지를 사용하였고, 연구 결과는 SPSS 10.0 통계패키지를 사용하여 $x^2$검정과 공분산분석(ANCOVA)으로 분석하였다. 중학생들의 뇌 기능 분화 양상을 분석해 본 결과, 좌뇌형이 21.6%, 우뇌형이 31.4% 그리고 양뇌형이 47.1%이었고 뇌 기능 분화의 분포는 성별에 따라 차이가 없었다(p>.05). 마인드 맵을 활용한 수업을 함으로써 우뇌 학생들의 학업성취도를 좌뇌 학생 이상으로 높힐 수 있었다. 사전검사에서는 우뇌형 학생의 성취도가 가장 낮았으나 사후검사때서는 우뇌형 학생들의 학업성취도가 가장 많이 향상되었다. 따라서, 마인드 맵을 활용한 수업은 우뇌형 학생들의 학업성취도 향상에 효과적이고 우뇌형 학생들에게 고무적인 교수학습방법이 될 수 있다고 본다. 그리고 마인드 맵을 활용한 수업은 전통적 수업에 비해 남학생들보다는 여학생에게 효과적이어서 여학생들에게 고무적인 여학생 친화적인 과학 학습전략이 될 수 있다고 생각된다.

• Clinical and Experimental Reproductive Medicine
• /
• 제40권3호
• /
• pp.122-125
• /
• 2013

Objective: The majority of embryo transfers (ETs) to date have been performed on day 3 to reduce the potential risk of developmental arrest of in vitro cultured embryos before ET. Development of sequential media has significantly improved culture conditions and allowed blastocyst transfer on day 5. While day 5 ET provides higher clinical pregnancy outcomes with reduced risks of multiple pregnancies, it still has potential risks of developmental arrest of IVF embryos. The aim of this study was to evaluate the clinical outcomes of day 4 ETs and compare the efficacy of day 4 ET with day 5 ET. Methods: From 2006 to 2009, a total of 747 fresh IVF-ET cycles were retrospectively analyzed (day 4, n=440 or and day 5, n=307). The cycles with any genetic factors were excluded. The rates of matured oocytes, fertilization, good embryos, and clinical pregnancy of the two groups were compared. The chi-square test and t-test were used for statistical analysis. Results: There were no significant differences between the two groups with respect to the mean age of the females and rates of matured oocytes. The pregnancy outcomes of day 4 ET (40.7%) were similar to those of day 5 ET (44.6%). The implantation rate of day 5 ET (24.2%) was significantly higher than that of day 4 ET (18.4%) (p=0.003). Conclusion: Day 4 ET can be chosen to avoid ET cancellation in day 5 ET resulting from suboptimal circumstances in the IVF laboratory, but the decremented quality of embryos for transfer and the decreased pregnancy rate must be taken into consideration.

• 치위생과학회지
• /
• 제15권3호
• /
• pp.369-376
• /
• 2015

본 연구는 서울시 일개 치과의원에 내원한 환자를 대상으로 치과공포 수준을 측정하고, 치과공포 수준 감소를 위한 중재법에 대해 환자가 요구하는 방법을 적용한 후 치과공포 중재법의 효과를 측정하였다. 개입한 치과공포 중재법에 대해서는 전체적으로 '도움이 된다(3.57점)'는 의견이었고, 항목별로는 '어떤 진료인지 미리 설명해 준다(4.38점)', '진료 중에 환자가 손을 들면 언제든 치료를 잠시 멈추어 준다(4.35점)', '진료 중 통증이 발생할 것 같으면 미리 말해준다(4.24점)', '의료진이 부드럽고 웃는 표정을 한다(4.06점)' 순으로 도움이 된다고 하였다. 치과공포 중재법 적용 전과 후의 전체적인 만족도는 각각 4.37점과 4.35점으로 높은 수준이었으나, 적용 후 미미하게 감소하였으며 이는 치과치료 항목과 밀접한 연관이 있을 것으로 사료된다. 치과공포 수준을 감소하기 위해서는 환자의 치과공포 수준 뿐 아니라 치과공포 중재를 위한 요구도를 파악하여 이에 맞는 개입방법을 적용하여 주는 것이 효과적이며, 이에 대한 치과의료 인력에 대한 교육과 매뉴얼 개발이 필요하리라 생각된다.

• 치위생과학회지
• /
• 제18권3호
• /
• pp.164-171
• /
• 2018

To improve the oral health status of Korean people, it is necessary to encourage proper oral hygiene management habits, such as toothbrushing, through appropriate health promotion techniques. Therefore, the purpose of this study was to evaluate the removal of plaque and tooth abrasion using ultra-soft (filament 0.11~0.12 mm) and soft toothbrushes for toothbrushing. The plaque removal was performed using a dentiform and Arti-spray, and the Patient Hygiene Performance (PHP) index was calculated as the sum total score divided by the total number of surfaces. In the abrasivity experiment, according to the number of brushings, a micro Vickers hardness tester was used, and a sample in the range of 280~380 Vickers hardness number was selected. The number of toothbrushing stroke were 1,800 (2 months), 5,400 (6 months), 10,800 (12 months), and 21,600 (24 months). The tooth abrasion was measured using a scanning electron microscope. Statistical analysis was performed using IBM SPSS Statistics 22.0 and a p-value <0.05 was considered significant. According to the results, there was no statistically significant difference in the degree of plaque removal between ultra-soft and soft toothbrushes. The difference in tooth abrasion between before and after toothbrushing was found to be greater with the soft toothbrushes than with the ultra-soft toothbrushes. Therefore, the ultra-soft toothbrush not only lowers tooth damage by reducing tooth abrasion, but also shows a similar ability to remove plaque as soft toothbrushes.

• 한국균학회지
• /
• 제24권3호통권78호
• /
• pp.186-205
• /
• 1996

식품으로서의 가치가 증가하고 있는 느타리버섯(Pleurotus ostreatus) 이핵체와 이것의 자실체로부터 얻은 35 단포자분리균주의 핵산연쇄중합반응에 의한 DNA 다형성을 분석하여 몇가지 유전형질과의 관계를 검토하였다. 느타리의 300개 단포자분리균주중에서 다시 이차로 분리한 35균주의 균총생장 속도를 분석한 결과 4균주는 모균주와 유사한 경향을 나타내었고 느린 것, 아주 느린 것으로 나눌 수 있었다. 26개의 Primer를 사용한 RAPD 분석에서 모균주와 단포자분리균주간에 형성된 DNA 다형성 밴드는 345개로, 밴드의 크기는 $0.1{\sim}4.0Kb$였다. Primer J(OPA-01)와 W(OPB-04)는 균주간에 많은 차이를 보였고, 36-MI 103균주는 거의 모든 primer에서 다른 균주와 차이를 나타냈다. RAPD 분석에 의한 모균주와 단포자분리주의 유전유사도는 36-MI 103을 제외하고 약 73% 정도의 유전유사성을 보였으며, 36-MI 103 균주와 다른 분리균주간의 유사도는 49%로 낮았다. 모균주 및 단포자 분리균주들의 유전유사도는 균사 생장속도와 다소 상관이 있는 4개 군으로 나눌 수 있었는데 I군은 이핵성 모균주, II군은 빠른 생장의 단핵주, III군은 중간 및 느린 생장속도의 단핵주, IV군은 아주 느린 생장속도의 단핵주였다. 그러나 교배형과 유연관계는 상관관계가 없는 것으로 나타났다.

• 한국임상수의학회지
• /
• 제26권3호
• /
• pp.205-211
• /
• 2009

Perioperative pain relief is essential in veterinary practice. However, the cat is one of the most poorly understood species regarding pain control management. Ovariohysterectomy(OHE) produces considerable postoperative pain in cats. Practitioners are often reluctant to administer analgesics due to lack of familiarity with available drugs, concern about side effects, or frustration with the need for record keeping of controlled substances. The purpose of this study was to determine if intraperitoneal administration of bupivacaine can provide relief of pain following OHE in cats. Twelve healthy female cats were randomly divided into two groups. OHE was performed under general inhalation anesthesia. Just prior to complete closure of the linea alba, 6 cats in SAL group received 0.88 ml/kg 0.9% saline, 6 cats in BUP group received 4.4 mg/kg 0.75% bupivacaine diluted to an equivalent volume with saline in the intraperitoneal space. Cats were scored at 0, 1, 2, 4, 8, 12 and 24 hours post-extubation by one observer. Cats were evaluated using a visual analogue scale(VAS) and composite pain scale(CPS) that included physiologic variables. There were no significant differences in body weight, anesthesia time, surgery time, and incision length between the two groups. Cats in the BUP group had significantly(p<0.05) lower VAS-pain scores than cats in the SAL group at 4, 8, 12 hours after surgery. Cats in the BUP group had significantly lower CPS scores than cats in the SAL group at 8, 12 hours after surgery. No adverse side effects were observed. These results support that the intraperitoneal administration of bupivacaine following OHE can be used for the prevention of postoperative pain and pain-induced behavioral changes in cats.