• Title/Summary/Keyword: Retrograde

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A Study on High Energy Ion Implantation for Retrograde Well Formation (Retrograde Well 형성을 위한 고에너지 이온주입에 대한 연구)

  • 윤상현;곽계달
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.5
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    • pp.358-364
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    • 1998
  • Retrograde well is a new process for ULSI fabrication. High energy ion implantation has been used for retrograde well formation. In this paper the forming condition for retrograde well using high energy ion implantation is compared with that for conventional well. TW signals for retrograde p-,n-well($900^{\circ}C$),after annealing are similar trends to those of conventional ones($1150^{\circ}C$), however the signals for RTA have the highest value because of small thermal budget. Junction depths of retrograde well are varied from about 1.2 to $3.0\{mu}m$ as for conventional well. The peak concentrations of retrograde well, however, are about 10 times higher in values than those of conventional ones so that they can be used as any types of potential barriers or gettering sites. The critical dose for phosphorus implantation in our experiments is between $3\times10^{13} and 1\times10^{14}/cm^2$. Under the above critical dose, there are many secondary defects near projected range such as dislocation lines and dislocation loops.

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Experimental Study on Distally Based Free Flap Using Retrograde Arterial Flow (역행성 동맥 혈류를 이용한 원위 유리피판술의 실험적 연구)

  • Lee, Min-Goo;Minn, Kyung-Won
    • Archives of Reconstructive Microsurgery
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    • v.7 no.1
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    • pp.15-19
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    • 1998
  • Microsurgical free-tissue transfer has allowed surgeons to salvage injured limbs but choosing appropriate healthy recipient vessels has proved to be a difficult problem. Retrograde flow flaps are established in island flaps. Retrograde flow anastomosis could prevent the possible kinking and twisting of the arterial anastomosis. By not interrupting the proximal blood flow to the fracture or soft tissue defect site, the compromise of fracture or wound healing might be prevented. We wished to estabilish an animal model in rat for a retrograde arterial flow based free flap. Nembutal-anesthetized male rats; weighing 250 to 300 gm, were used. The femoral artery and common carotid artery were exposed and divided. The systemic and retrograde arterial pressure were quantified by utilizing a parallel tubing system connected with peripheral arterial line. In this study, the retrograde flow was not pulsatile and the retrograde arterial pressure was 64-65mmHg, with a mean arterial pressure of 106-109mmHg. An epigastiic skin flap, measuring $3{\times}3cm$, was raised with its vascular pedicle. The epigastric free flap was transfered in the same rat from femoral vessels to carotid vessels in end to end fashion. We anastomosed the donor arteries to the distal parts of the divided recipient arteries and the donor veins to the proximal parts of the recipient veins. Twelve experiments were performed and the transplantations succeeded in 75 percent of them. In the remaining 25 percent, the experiments failed due to thrombosis at the site of anastpmosis, or other causes. This animal model represents an excellent example of retrograde arterial flow free flap transfer that is reliable.

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Study on the Application of Retrograde Intravenous Regional Anesthesia in Claw Lamed Cows (발굽 천행우에서 회귀성 국부 정맥무취위 활용에 관한 연구)

  • 정순욱
    • Journal of Veterinary Clinics
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    • v.15 no.1
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    • pp.56-61
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    • 1998
  • A retrograde intravenous regional anesthesia was applied to the extremities of 30 cows, which was showed that mean value of induction time was 13.5 seconds, duration time 74.4 minutes, frequency of injection until to keep needle into the vein 1.27, and didn't observed local and systemic complications. Under the retrograde intravenous regional anesthesia, it was possible for surgical treatment of 20 cows with various foot disorders, to resect soft tissues of extremities and claw horns, to sexarticulate 2nd phalanx without pain reactions.

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Gate Workfunction Optimization of a 32 nm Metal Gate MOSFET for Low Power Applications

  • Oh Yong-Ho;Kim Young-Min
    • Journal of Electrical Engineering and Technology
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    • v.1 no.2
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    • pp.237-240
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    • 2006
  • The feasibility of a midgap metal gate is investigated for a 32 nm MOSFET for low power applications. The midgap metal gate MOSFET is found to deliver $I_{on}$ as high as a bandedge gate if a proper retrograde channel is used. An adequate design of the retrograde channel is essential to achieve the performance requirement given in the ITRS roadmap. A process simulation is also run to evaluate the feasibility of the necessary retrograde profile in manufacturing environments. Based on the simulated result, it is found that any subsequent thermal process should be tightly controlled to retain transistor performance, which is achieved using the retrograde doping profile. Also, the bandedge gate MOSFET is determined be more vulnerable to the subsequent thermal processes than the midgap gate MOSFET. A guideline for gate workfunction $(\Phi_m)$ is suggested for the 32 nm MOSFET.

A RETROSPECTIVE CLINICAL STUDY OF PERIAPICALLY INFECTED TEETH TREATED WITH PERIAPICAL SURGERY (치근단 감염 치아의 치근단 수술 후 예후에 관한 후향적 연구)

  • Kim, Hyeon-Min;Park, Chul-Hwi;Lee, Sang-Chil;Kim, Dong-Woo;Park, Dae-Song;Jung, Jin-Hwan;Lee, Seul-Ki;Song, Min-Seok
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.32 no.3
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    • pp.236-241
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    • 2010
  • Purpose: The purpose of this retrospective clinical study was to monitor the outcomes of periapical surgery in periapically infected tooth with or without retrograde filling materials (MTA or IRM). Patients and Methods: A total of 85 teeth in 63 patients were included in the study between November 2004 and August 2008. Randomly, MTA or IRM was used as a retrograde filling material or only apical resection without retrograde filling. Teeth with advanced periodontal bone loss or presence of root fracture were excluded from the study. The patients were subjected to a minimum follow-up period of 12 months, with a mean of 17.1 months. Results: Successful healing was observed in 83.3% of the MTA-treated teeth, 80% of the IRM-treated teeth and 75% of the teeth which was not retrograde filling. Doubtful healing was seen 9.3% (MTA), 13.3% (IRM), 12.5% (no retro-filling). The success rate of upper incisors (92%) was higher than lower lincisor and molars (66.7% and 50%, respectively). Conclusion: In this study, periapical surgery including retrograde filling improves the prognosis. And, no statistically significant differences were found between retrograde filling materials (MTA or IRM).

THE EFFECT OF ND : YAG LASER ON DENTINAL TUBULE SEAL AFTER ROOT END RESECTION (치근단절제시 노출된 상아세관의 밀폐효과에 대한 Nd : YAG 레이저의 효과)

  • Shin, Kwang-Chul;Hong, Chan-Ui
    • Restorative Dentistry and Endodontics
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    • v.21 no.1
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    • pp.311-320
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    • 1996
  • If root and resection is done during surgical endodontic treatment, newly exposed dentinal tubules form pathways between the canal and the peripheral tissue. Nd : YAG laser was used to block this phenomenon, and its effect was studied with dye penetration and SEM techniques. 40 intact single rooted teeth were divided into 4 groups(10 each) : control group and test groups, in which retrograde cavity surface, cutting surface, retrograde cavity surface & cutting surface were treated with laser(1 watt 15pps) and finally retrograde filling with IRM was conducted. After that, they were stained with 2 % methylene blue, sectioned and evaluated by the maximum infiltration depth. And to observe surface change, they were prepared for SEM. The results were as follows ; 1. All experimental groups showed microleakage with variation in amount. 2. The 2nd group which treated both the retrograde cavity and cutting surface showed significantly less microleakage than the other groups(p<0.05). There was no significant difference between groups treated on one side only. 3. As a result of SEM observation of dentin surface, obstruction of dentinal tubules with marble shaped granules, which were different from normal dentin could be seen. Cracks could be seen also. 4. In summary of this experiment, it is thought that effort to obstruct the exposed dentinal tubules as well as retrograde cavity after root end resection is needed.

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A STUDY OF THE APICAL LEAKAGE OF VARIOUS RETROGRADE TECHNIQUES (치근단 폐쇄방법에 따른 변연누출에 관한 실험적 연구)

  • Park, Sang-Ho;Lee, Chan-Young;Lee, Seung-Jong;Lee, Chung-Suck
    • Restorative Dentistry and Endodontics
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    • v.11 no.1
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    • pp.53-61
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    • 1985
  • This study was conducted to evaluate and compare the apical leakage in the following retrograde techniques; apicoectomys, retrograde filling with zinc oxide eugenol cement, non-zinc and zinc amalgam, and cold-burnished gutta-percha method. One hundred twenty five upper anterior and lower premolar teeth were divided into five above mentioned groups and each tooth was individually prepared for its particular group. The specimens were incubated at $37^{\circ}C$ for 14 days and then were infiltrated by 2% methylene blue for 24 hours. The apical leakage was evaluated by measuring the degree of dye penetration between the filling material and the canal wall. The results were as follows: 1. The cold-burnished gutta-percha group showed the least amount of apical leakage and the apicoectomy group showed the greastest amount of apical leakage. 2. Statistics showed that there were significant differences among the groups (P<0.05), however there was no difference between the zinc oxide eugenol cement retrograde filling group and the non-zinc amalgam retrograde filling group (P>0.05).

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Lightening up Light Therapy: Activation of Retrograde Signaling Pathway by Photobiomodulation

  • Kim, Hong Pyo
    • Biomolecules & Therapeutics
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    • v.22 no.6
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    • pp.491-496
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    • 2014
  • Photobiomodulation utilizes monochromatic (or quasimonochromatic) light in the electromagnetic region of 600~1000 nm for the treatment of soft tissues in a nondestructive and nonthermal mode. It is conceivable that photobiomodulation is based upon the ability of the light to alter cell metabolism as it is absorbed by general hemoproteins and cytochrome c oxidase (COX) in particular. Recently it has been suggested radiation of visible and infrared (IR) activates retrograde signaling pathway from mitochondria to nucleus. In this review, the role of COX in the photobiomodulation will be discussed. Further a possible role of water as a photoreceptor will be suggested.

Retrograde Cerebral Perfusion in the Surgical Treatment of Ascending Aortic Aneurysm -Report of 4 Cases- (역행성 뇌혈 관류를 이용한 상행대동맥류 수술 -4례 보고-)

  • 문승호
    • Journal of Chest Surgery
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    • v.28 no.8
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    • pp.788-791
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    • 1995
  • Dissecting aortic aneurysm of ascending aorta is a life threatening condition which requires prompt surgical correction. With deep hypothermic circulatory arrest and retrograde cerebral perfusion via superior vena cava, we could replaced ascending aorta in 4 cases safely. All of 4 cases; femoral artery, right auricle were used as cannulation site. The duration of circulatory arrest were 28, 30, 45, 60 minute in each cases and rectal temperature was 2$0^{\circ}C$ at that time. At the time of retrograde cerebral perfusion, we maintained central venous pressure under 25mmHg. We resected all of dissecting portion and replaced it with Hemashield graft. There were no deaths but two of four reoperated because of bleeding.

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Latchup characteristics of BL/BILLI retrograde twin well CMOS with MeV ion implanted Bored Layer (MeV 이온주입에 의한 매입층을 갖는 BILLI retrograde well과 latchup 특성)

  • Kim, Jong-Kwan;Kim, In-Soo;Kim, Young-Ho;Shin, Sang-Woo;Sung, Yung-Kwon
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1270-1273
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    • 1997
  • We have investigated the latchup characteristics of BL/BILLI retrograde twin well CMOS that has the high energy ion implanted buried layer to intend for more improvement of latchup compare to conventional retrograde well and BILLI structures. We explored the dependence of various latchup characteristics such as n+ trigger latchup and p+ trigger latchup on the buried layer implant doses. We show various DC latchup characteristics that allow us to evaluate each technology and suggest guidelines for the reduction of latchup susceptibility.

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