• 대한치과보철학회지
• /
• 제36권2호
• /
• pp.336-354
• /
• 1998

Traditionally, many kinds of mechanical bonding techniques were used for bonding resins to the surface of the metal alloys. If there is a seperation between resin and metal junction by stress accumulation and temperature change of oral cavity, the cracks or crazing may occur, accompanied by failure of resin bonding to metal. This study was designed to compare the shear bond strength of the type IV gold alloy and Cr-Co alloy surfaces treated with various methods and thermocycling. Universal Instron (Model 1000) and scanning electron microscope (JEOL, Japan) was used to record the shear bond strength of 5 groups. Forty specimens were made for each group ; group 1 was treated with sandblasting only, group 2 was coated with V-primer after sandblasting, group 3 was coated with Metal primer, group 4 wase coated with MR Bond and group 5 was coated with silane. After treated with various methods, thermocycling was done for half of the each group. The surfaces of failed pattern were observed with SEM. The results were as follows : 1. Shear bond strength of the group 1 was lower than that of another groups in type IV gold alloys and bond strength of the group 1, 2 were lower than that of group 3, 4, 5 in Cr-Co alloys. 2. Shear bond strength of the gold alloy with resin was higher than that of Cr-Co alloy when specimens were coated with V-primer. 3. Shear bond strength of the Co-Cr alloys with resin was higher than that of gold alloys when specimens were coated with Metal primer. 4. The bond strength of all specimens did not decreased significantly after thermocycling. 5. Adhesive failures were found in group 1 and Cr-Co alloy in group 2, but adhesive and cohesive failures were found in another groups.

• Applied Microscopy
• /
• 제25권1호
• /
• pp.1-14
• /
• 1995

The purpose of this study was to investigate the main sensory trigeminal nucleus in the aging rat brain by means of electron microscope. Male Sprague-Dawley rats, two (control group) and thirty six (aging group) months of age, were used. These animals were sacrificed by perfusion fixation with 2.5% glutaraldehyde-2.0% paraformaldehyde (0.1M phosphate buffer, pH 7.4) under sodium pentobarbital. The objective area was punched out with a sharp-edged metal cylinder of 0.8 mm in diameter. These blocks of tissue were then washed in 0.1M phosphate buffer, postfixed in 2% osmium tetroxide, dehydrated in a graded series of ethyl alcohol, and embedded in Epon 812. Thin sections were cut with Super Nova ultramicrotome, pick up on grids and double stained with lead citrate and uranyl acetate, and observed in JEOL 100B electron microscope. The results were as follows: 1. In the control group, the neuronal cell body of the main sensory trigeminal nucleus was filled with nucleus, Golgi complex, Nissl substance, mitochondria, microfilaments and microtubules. However, few Nissl substances are seen in neuronal cell body. Axoaxonic synapse, axodendritic synapse, axosomatic synapse, axospinous synapse, myelinated and unmyelinated nerve fibers were well organized around cell bodies. Neurons with abnormal changes were not seen. 2. In the aging group, the neuronal cell body of the main sensory trigeminal nucleus contained large number of lipofuscin granules, dense body and swollen mitochondria. Terminal boutons contained glycogen, crystal-like vesicle and membranous indicating first signs of degeneration. The dendrites were found to be in synaptic contact with altered axon terminals. Frequently axons filled with dark axoplasn and splitted myelin sheath were noticed.

• Restorative Dentistry and Endodontics
• /
• 제23권2호
• /
• pp.690-700
• /
• 1998

Rubber-toughened particles which are used in the field of chemical engineering are used to increase the fracture toughness of thermoset resin. The application of Core-Shell particles, one of rubber-toughened particles, as a filler for dental composite or restoration have not been examined. The purpose of this study was to evaluate possible use of Core-Shell particles for dental composite, and the hypothesis was that additional toughening mechanisms are activated by the addition of Core-Shell particles. After blending 50vol% quartz with Bis-GMA/TEGDMA resin matrix, the experimental resins were made by the addition of Core-Shell particles with varied content level as 0, 2.5, 5, 7.5, 10, 12.5, 15, and 20wt%. Fracture toughness was determined on three-point bending specimen with single-edge notch according to ASTM-E 399. Also, flexural properties, that is, strength and modulus were measured by three-point bending testing. Fractogragh of fracture toughness specimen was observed using SEM (JEOL 6400 SEM, MA). The following results from this study were obtained ; 1. Fracture toughness of composite resin added 2.5wt% Core-Shell particles was significantly higher than control group ($p{\leq}0.05$). 2. Flexural properties were decreased with increasing Core-Shell particle content, which showed a correlation statistically ($p{\leq}0.05$). 3. A toughening mechanism such as lamination and microcrack was observed in specimen determined high fracture toughness. 4. The dispersion of Core-Shell itself and quartz filler particles was limited present high content of Core-Shell particles, which decreased a resulting mechanical properties of composites. These results suggest that adequate Core-Shell particles can be used to enhance mechanical properties included toughening for dental composites.

• Applied Microscopy
• /
• 제22권2호
• /
• pp.118-126
• /
• 1992

The pathway and time course of fucose-containing glycoprotein synthesis and intracellular translocation in osteoclasts of the mice maxillary alveolar bone were investigated by electron microscopic radioautography. Male Balb-C mice weighing 17gm were anesthetized with Nembutal and injected via the external jugular vein with 2.5 mCi of $L-[6-^{3}H]-fucose$ (specific activity 16.8 mCi/mmol) in 0.1 ml of sterile saline solution. At 5, 10, 20, 35 minutes and 8 hours after administration of the $^{3}H-fucose$, animals were killed by intracardiac perfusion of 30ml of 2% glutaraldehyde in a modified Tyroid solution, pH 7.4. The maxillae were then removed and further fixed in Karnovsky fixative for an additional 3-4 hours. After rinsing in 0.1M cacodylate buffer for 10 minutes, the maxillae were demineralized for 2 weeks at $4^{\circ}C$ in ethylene diamine tetra acetate containing 2% glutaraldehyde. The first interdental areas were mesiodistally sectioned into slices of 1mm thickness and postfixed in osmium tetroxide. Tissues were then dehydrated and embedded in Poly Bed. To prepare electron microscopic radioautography, the dipping method of Kopriwa (1973) was employed. Thin sections were coated with a crystalline monolayer of ILford $L_4$ photographic emulsion. After exposure for 4 months at $4^{\circ}C$, the sections were developed Kodak Microdol-X and Phenidon (for compact grains), fixed in 30% sodium thiosulfate, stained with uranyl acetate and lead citrate and examined in the electron microscope (JEOL 1200 EX). At 5, 10 and 20 minutes after injection, $^{3}H-fucose$ was concentrated in Golgi cisternae of the osteoblasts. By 35 minutes the labels were observed over small vesicles in the suprannclear area of osteoclasts. At 8 hours, numerous silver grains were located on the ruffled border and cell membrane of osteoclasts. These results indicate that fucose molecules are added in the Golgi apparatus and small vesicles appear to be responsible for translocation of the glycoproteins to the marginal portion of osteoblasts. The glycoproteins are distributed on the osteoclast cell surface and especially over the ruffled border.

• Restorative Dentistry and Endodontics
• /
• 제17권2호
• /
• pp.365-382
• /
• 1992

The purpose of this study was to evaluate the adaptation of filling material to the dentinal walls of root canals with and without smear layer. Fifty extracted upper and lower anterior teeth were selected, and the root canals were instrumented with K - files 1mm short of the apical foramen by step - back method. The teeth were randomly divided into two groups of 25 each : in the group I, smear layers were not removed, and in the group II, smear layers were removed by 15% EDTA solution. Again the two groups 25 teeth were randomly divided into unfilled contol group and filling groups(lateral, ultrasonic, ULTRAFIL, McSpadden compaction group). Upon completion of root canal filling, the teeth were grooved on the both the labial and lingual surfaces and then split with mallet and chisel. Each specimens were examined with JSM - 840 Scanning Electron Microscope (JEOL., Japan). The results were as follows : 1. In the contol group, dentinal tubules of group I couldn't be distinguished in the canal wall, but those of group II appeared to be open and patent. 2. In the filling groups of group I, the tubular penetration of the sealer or gutta percha couldn't be seen, but in the filling groups of group II, it could be seen except McSpadden compaction group. 3. In the filling groups, ULTRAFIL group showed the best adaptation of filling material to root canal wall among the group I, and lateral and ultrasonic condensation group showed the best adaptation of filling material among the group II. McSpadden compaction group showed the worst adaptation in group I, II. 4. Generally, the group II showed better adapation of filling material to root canal wall than the group I.

• PNF and Movement
• /
• 제8권2호
• /
• pp.1-8
• /
• 2010

Purpose : The purpose of this study was to investigate the effects of proprioceptive exercise (PE) using a trampoline and a balance board on a balance ability after stroke. Method : Sixteen chronic stroke patients participated. Participants were randomly assigned to the PE group or control group (8 experimental, 8 control). All of participants were in-patients at local rehabilitation centre and had been receiving a traditional rehabilitation program, five days a week. The PE group have additionally undergone for four weeks, three days a week, the PE using a trampoline and a balance board under supervision by a physical therapist but control group was not received any additional program except the traditional rehabilitation program. The position sense test used to assess a proprioceptive sense at a knee joint. The Berg Balance Scale (BBS) and the Timed Up & Go (TUG) test to measure the balance ability were carried out before and after the training. Result : After the training the error of position sense at knee joint of PE group significantly decreased compared to the control group. The PE group demonstrated a significant improvement in the scores of the BBS and TUG. Conclusion : The present study suggests that the PE program using a trampoline and balance board may become a useful tool for enhancing a balance ability in chronic stroke patients through the ennced proprioceptive position senses.

• 대한한방부인과학회지
• /
• 제20권1호
• /
• pp.239-257
• /
• 2007

Purpose : In the part of Ob & Gy disease, the health insurance application is very limited. This study has been performed for gaining the basic data of enlargement of insurance coverage and reform of the insurance system corresponded with real clinical conditions. Methods : The survey has been practiced twice, the subjective questionnaire was used at the first survey. Then the questionnaire written using the results of first survey was distributed to the Korean medical doctors(KMD) who participated in the autumn symposium of the society of Oriental Obstetrics & Gynecology. Results : 1. The main Ob & Gy disease that the acupuncture treatment has been used actually or thought be positively necessary on the clinic were Dysmenorrhea(including premenstrual syndrome), Climacteric syndrome, Menstrual disorder, Postpartum Pain syndrome. Amenorrhea, Low back pain with pregnancy, JingHa(pelvic tumor), Infertility etc. 2. The main additional complex the sick and wounded names given to visiting patients for Ob & Gy disease as the limits of acupuncture items of insurance coverage were Low back Pain(J10), Qi-stasis(B13.0), SimHwaHangYeom(C2l.1). 3. Suitable the sick and wounded name of Ob & Gy disease thought be added in BokGangNae(Intra-abdominal acupuncture: CV13 ${\cdot}$CV16${\cdot}$CV10). TuJa(Puncture each adjoining acu-points in one insertion : SP6-GB39), TuJa(PC6-TE5) among acupuncture items of insurance coverage were Dysmenorrhea(K05). Menstrual disorder(K02) and Dysmenorrhea(K05), Hyperemesis(K16.0). 4. Climacteric syndrome(K04) and Dysmenorrhea(K05) should be added as suitable the sick and wounded name of TuJa(SP6-GB39), and Postpartum pain syndrome(K29) as KwanJeolGangNea(Intra-articular acupuncture: S35, LE201). Conclusion : Standing on this study, additional survey to general KMD should be continued. And the academic verifications through the oriental medical literatures and RCT papers on acupuncture should be also required.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.453-453
• /
• 2013

유기 태양전지는 저비용으로 제작이 가능하고 제작이 용이한 장점을 가지고 있으므로 많은 그룹에서 관심을 가지고 있다. 정공 수송층으로 사용되는 PEDOT:PSS는 많이 사용되지만 강한 산성 특성 때문에 ITO 전극에 식각이 되므로 문제가 있다. 그러므로 산화물 반도체 $WO_3$, $MoO_3$, 그리고 $V_2O_3$ 등이 태양전지에 많이 만들어지고 있다. 특히 copper oxide는 높은 광흡수율을 가지고 있으므로 태양전지에 사용하는 데 많은 기대되는 물질이다. Copper oxide 박막은 열증착 법, 스프레이 필로시스, 전기화학 증착, 화학증착법, 그리고 솔-젤법 등 다양한 증착 방법이 있다. 넓은 면적의 소자를 제작할 경우 솔-젤 방법은 기존의 증착법에 비해 낮은 비용으로 제작, 높은 성장율, 그리고 높은 기계적 탄력성의 장점이 있다. 솔-젤법으로 만든 copper oxide는 P3HT의 HOMO (high occupied molecular orbital)와 비슷한 위치에 접하고 있으므로 정공수송층으로 적합하다. 본 연구에서 제작된 태양전지의 구조는 ITO/P3HT:PCBM/CuxO로 구성되어 있다. ITO가 $10{\Omega}$/sq의비저항을 가지고 있었고 UV 처리를 하였다. 그 위에 P3HT:PCBM (1:0.8 weight)를 스핀 코팅하였다. 마지막으로 0.1 M $Cu_xO$용액은 Cu (II) acetate monohydrate를 소스로 2-methoxyethanol ($C_3H_8O_2$)의 용제와 안정제로 monoethanolamine ($C_2H_7NO$)을 섞어서 만들었다. 그리고 P3HT:PCBM 위에 스핀 코팅하였고 열증착 방법으로 전극인 Ag 을 증착하여 최종 소자를 만들었다. Cu(II) acetate의 소스로 제작된 박막의 투과율 측정을 통해 에너지 밴드갭을 구할 수 있었다. Copper oxide 박막은 다결정구조 이므로 다중 밴드갭으로 구성되어지는 것을 알 수 있었다. 최종적으로 만들어진 소자를 열처리를 통해 소자 특성을 조사했더니 250도에서 가장 좋은 결과를 얻을 수 있었다.

• 식물분류학회지
• /
• 제39권4호
• /
• pp.309-314
• /
• 2009

전남 구례군, 광주광역시 그리고 인천광역시에서 미기록 귀화식물 2종을 발견하였다. 유럽육절보리풀로 이름 붙인 Glyceria declinata $Br{\acute{e}}b$.(벼과)는 전남 구례군 구례읍 섬진강 부근과 광주광역시 동구 사동 광주천 부근에서 확인되었으며, 근연 분류군인 육절보리풀(G. acutiflora)과 비교하여 소수의 길이는 15-20mm로 짧고, 호영의 끝부분이 뭉툭한 특징으로 구별된다. 또한 처진미꾸리광이로 이름 붙인 Puccinellia distans (Jacq.) Parl. (벼과) 는 인천광역시 영종도, 용유도, 강화군 초지진 등에서 확인되었으며, 근연 분류군인 갯꾸러미풀(P. nipponica)에 비해 호영은 길이 1.8-2.5mm이고, 엽설은 길이 1-2mm로 더 작고, 개화기 후 화서의 밑 부분 가지가 밑으로 젖혀지는 특징으로 구별된다.

• 대한한의진단학회지
• /
• 제9권2호
• /
• pp.25-56
• /
• 2005

Background and purpose: Gin Ga Chu Yo(診家樞要) was written in the year 1359 by Hwal Su(滑壽) who was a famous oriental doctor between Won(元) and Myeong(明) dynasty. As specialized in sphygmology(脈學), this book was brought together most things about sphygmology(脈學) before Won(元) dynasty by the author. Moreover he added the self-realized things to this book. Methods: In this book, besides a author's preface, there are all 20 chapters which are Chu Yo Hyeon Eon(樞要玄言), Jwa U Su Bae Jang Bu Bu Wi(左右手配臟腑部位), O Jang(五臟), Sa Si peong Maek(四時平脈), Nae Gyeong Sam Bu Maek Beop(內經三部脈法), Ho Heup Chim Bu Jeong O Jang Beop(呼吸沈浮定五臟法), In Ji Ha Gyeong Jung I Jeong 0 Jang Beop(因指下輕重以定五臟法), Sam Bu So Ju(三部所主), Ji Maek Su Beop(持脈手法), Maek Gwi Yu Sin(脈貴有神), Maek Eum Yang Yu Seong(脈陰陽類成), Gyeom Hyeon Maek Ryu(兼見脈類), Je Maek Ui Gi Ryu(諸脈宜忌類), Heom Je Sa Jeung Ryu(驗諸死症類), Sa Jeol Maek Ryu(死絶脈類), O Jang Dong Ji Maek(五藏動止脈), Bu In Maek Beop(婦人脈法), So A Maek Beop(小兒脈法), Maek Sang Tong Hoe(脈象統會), Maek Sang Ga(脈象歌) and an epilogue in the end. Result and Conclusion: Looking into this book, we can know that it is very detail in analyzing item by item, bright and simple in explaining and it is very useful in studying pulse evaluation(脈診). In his preface, Hwal Su(滑壽) expresses his opinion with firm confidence that ‘Do(道) of the World scattered in several scholarships and books of method and technique(方術). Nothing of method and technique(方術) is more important than medicine. Nothing of medicine goes before pulse evaluation(脈診).’ With such good reasons, as a student of sphygmology(脈學), I think this book is very valuable in studying pulse evaluation. So I add Hangul suffixes(吐) to a part of this book and translate it into Korean.