• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.231-234
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• 2002

Ultrasonic machining technology has been developed over recent years for the manufacture of cost-effective and quality-assured precision parts for several industrial application such as optics, semiconductors, aerospace, and automobile. Ultrasonic machining process is an efficient and economical means of precision machining of ceramic materials. The process is non-thermal, non-chemical and non-electric and hardly creates changes to the mechanical properties of the brittle materials machined. This paper describes the characteristics of the micro-hole of $\textrm{Al}_2\textrm{O}_3$ by ultrasonic machining with tungsten carbide tool. The effects of various parameters of ultrasonic machining, including abrasives, machining force and pressure, on the material removal rate, hole quality, and tool wear presented and discussed. The ultrasonic Machining of micro-holes in ceramics has been under taken and the machining mechanism in the ultrasonic machining of ceramics based on the fracture-mechanics concept has been analyzed.

• 대한수의학회지
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• 제34권2호
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• pp.395-406
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• 1994

To study the conditions to enhance success of embryo transfer in the dog, 20 mixed-breed bitches were used for the experiment along with 4 male dogs for mating. The bitches were paired according to synchronism of natural estrus, or the counterpart as donor or recipient was treated with gonadotropin as FSH (follicular stimulating hormone) or PMSG (pregnant mare serum gonadotropin) for induction of estrus to be synchronized with estrus of the other bitch in natural estrus. Embryo recovery was performed in two ways for comparison, either by flushing each uterine horn after ovariohysterectomy or by flushing each horn in the state of non-ovariohysterectomy. In addition, the result of pregnancy according to the embryo stage and the repeatability of the experimental animals as donor or recipient were also investigated. FSH or PMSG was administered to the bitches which had passed over 4 months from last estrus, resulting in estrus-positive in 3 dogs of 6 FSH-treated dogs (50.0%), and in 5 dogs of 9 PMSG-treated dogs (55.6%), determined by proestrus signs and vaginal smear test. Estrus-positive bitches induced with gonadotropin were used as donor or recipient resulting in one embryo-recovered bitch as donor and one offspring-delivered bitch as recipient in 5 PMSG-treated dogs, whereas no result was obtained from 3 FSH-treated dogs. The rate of embryo recovery to be compared with number of corpus luteum was 68.2% in ovariohysterectomized dogs and 55.2% in non-ovariohysterectomized dogs, respectively. The number of dogs from which embryo was collected were 4 dogs of 6 ovariohysterectomized dogs (66.7%) and 6 dogs of 7 non-ovariohysterectomized dogs (85.7%), respectively. The result of parturition was obtained from one dog of 5 estrus-induced recipients, whereas no result was obtained from 3 natural-estrus recipients. The only dog which delivered a male puppy had been transferred 3 morulae and 2 blastocysts. Of 6 repeat-used bitches in canine embryo transfer, 3 dogs showed repeatability either as donor or recipient. These results indicated that inducing estrus of a dog with gonadotropin is feasible in canine embryo transfer to be synchronized with that of a natural-estrus dog, that embryo recovery is also possible in non-hysterectomized dogs, that the estrus-induced dog is also usable as recipient to result in parturition, and that repeat-use of a bitch as donor or(and) recipient is possible in canine embryo transfer.

• 대한수의학회지
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• 제12권1호
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• pp.133-139
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• 1972

Estrous and non-estrous rabbits were inoculated with E. coli or Streptococcus pyogenes, and the mixture of the two organisms, and bacterial count and histopathological studies of uterine horns were made to observe the effects of estrogen on the resistance of the uterus to bacterial infection. The results obtained were summarized as followings; 1. Four hours after inoculation of bactoria into uterine horn, the number of organisms was significantly lower in estrous rabbits than in non-estrous regardless of the kind of organisms inoculated. 2. The highest reduction rate of the organisms among the three bacterial inoculation groups was found in estrous rabbits inoculated with E. coli, and the lowest reduction rate was with Streptococcus pyogenes. 3. Histopathological changes of uterine horns induced five days after bacterial inoculation were observed. In estrous rabbits, a mild inflammatory reaction was found in Streptococcus pyogenes group, but a slight inflammatory reaction and only a negligible inflammatory reaction were observed in mixed bacteria group, and in E. coli group respectively. In non-estrous group, however, a marked inflammatory reaction was observed in Streptococcus pyogenes group, a moderate inflammatory reaction and a slight inflammatory reaction were observed in the mixed bacterial group and E. coli group, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제17권7호
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• pp.919-923
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• 2004

Ultrasonographic study was undertaken to establish the echogenecity and size of reproductive organs of 18 cycling buffaloes of different parities and compared with the sizes measured by palpation per rectum at estrus (day 0), met estrus (day 2), mid diestrus (day 10) and late diestrus (day 16). The overall mean size of cervix, uterine body, right horn, left horn, right ovary and left ovary measured by palpation per rectum were 2.70$\pm$0.43, 2.36$\pm$0.36, 2.17$\pm$0.37, 2.12$\pm$0.38, 2.63$\pm$0.41 and 2.72$\pm$0.37 cm, respectively. The corresponding ultrasonographic observations were 2.10$\pm$0.40, 1.85$\pm$0.30, 1.73$\pm$0.36, 1.64$\pm$0.37, 2.16$\pm$0.36 and 2.29$\pm$0.38 cm respectively. Variations in the size of genitalia due to stages of estrous cycle were non-significant. The size of genitalia measured by palpation per rectum was significantly higher (p<0.05) than by ultrasonography. However, there was linear positive correlation (r=+0.87) in the measurements by the two techniques. The ultrasonographic characteristics of tubular genitalia revealed different echogenic gray shades around the nonechogenic (black) central area of lumen depending upon the stage of cycle. The ovarian stroma appeared as hyperechoic (white) area with nonechogenic (black) follicle. The corpus luteum (CL) exhibited different echogenic texture viz. grayish black, grayish granular and grayish white at met estrus, mid diestrus and late diestrus, respectively. Therefore, ltrasonography can be effectively employed to record the exact size and echotexture of the buffalo genitalia during different stages of estrous cycle.

• International Journal of Oral Biology
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• 제39권1호
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• pp.49-56
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• 2014

이상의 실험결과들을 요약하면, CFA를 안면영역 피하로 주입하여 발생한 염증성 통증 행위반응은 P2X 수용체의 억제제의 투여로 감소할 수 있었다. 특히 $P2X_7$ 수용체 억제제를 투여하면 진통작용 뿐 아니라 활성화된 신경아교세포 발현을 억제하였다. 이러한 실험 결과는 $P2X_7$ 수용체가 신경아교세포에 영향을 미쳐 안면에서 발생하는 만성 염증성 통증의 발생과 유지에 관여하고 있다는 것을 보여준다. 따라서 중추신경계의 신경아교세포를 조절할 수 있는 중추성 $P2X_7$ 수용체 작용기전은 임상에서 만성 염증성 통증을 보다 효과적으로 치료할 수 있는 새로운 방법을 제시해 줄 수 있다고 생각된다.

• 한국임상수의학회지
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• 제15권1호
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• pp.94-99
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• 1998

This study was carried out to determine the effects of uterus shortening on the duration required for estrus, the number of ovulation and the level of serum progesterone and prostaglandin $F_{2}{\alpha} (PGF_{2}{\alpha} $). The duration required for estrus after the surgical shortening of uterine horns and the interval between the following estrus was not affected by the surgical treatment but affected by luteal and follicular phase. The number of ovulations were increased by induction of superovulation to gilts with shortened uterine horns compared to the control. Serum progesterone concentration during the luteal phase was higher than that during the follicular phase with no difference between the control and me horns than that of the control. Findings of this study indicate that luteal formation and regressions and estrus cycle were normal when the unconnected parts of uterine horns were left in abdominal cavity. Therefore surgical shortening of uterine horns of sows helps embryo collections by non-surgical methods.

• Journal of Hospice and Palliative Care
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• 제1권1호
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• pp.65-68
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• 1998

The neuropathic pains are not well controlled by common analgesics and opioid drugs in terminal cancer patients. The types of these pains are divided within the two cages, one is due to continuous central sensitization and the other is due to paroxymal peripheral sensitization. The mechanism of continuous central sensitization is the activity of dorsal horn neurones that are activated by C-fiber input. The tricyclic antidepressants, non-tricyclic antidepressants, and oral local anaesthesia probably produce analgesic effects in neuropathic pains through suppression of this activity. The mechanism of paroxymal peripheral sensitization is the hyper-excitability of peripheral neurones. The neuropathic pains due to peripheral sensitization respond relatively the anticonvulsants and baclofen that stabilize membranes and suppress paroxymal electrical discharge. The patients was a 38-year-old female who complained of hyperthemia on upper right extremity. The symptom of this patient was improved with anticonvulsant(dilantin 600mg).

• The Korean Journal of Physiology
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• 제30권2호
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• pp.289-297
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• 1996

Excitatory amino acids (EAA) are thought to play an important role in producing cell death associated with ischemic and traumatic spinal cord injury. The present study was carried out to determine if the response characteristics of spinal sensory neurons in segments adjacent to degeneration sites induced by EAA are altered following these morphological changes. Intraspinal injections of quisqualic acid (QA) produced neuronal degeneration and spinal cavitation of gray matter. The severity of lesions was significantly attenuated by pretreatment with a non-NMDA antagonist NBQX. In extracellular single unit recordings, dorsal horn neurons in QA injected animal showed the increased mechanosensitivity, which included a shift to the left in the stimulus-response relationship, an increased background activity and an increase in the duration of after-discharge responses. Neuronal responses, especially the C-fiber response, to suprathreshold electrical stimulation of sciatic nerve also increased in most cases. These results suggest that altered functional states of neurons may be responsible for sensory abnormalities, e.g. allodynia and hyperalgesia, associated with syringomyolia and spinal cord injury.

• 한국정보통신학회논문지
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• 제4권5호
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• pp.931-936
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• 2000

이 논문에서는 완만한 곡면을 모델링하기 위한 새로운 CPFDTD 앨거리즘을 제안한다. 이 구조에서는 기존의 근접 전계 대여 근사법을 피하기 위하여, 변형된 궤적상의 전계 성분을 확장 궤적 전계, 무변형 궤적 전계, 그리고 준-사용 전계로 세분한다. 기존의 몇몇 방법들과 개선된 방법을 I-면 흔 안테나의 해석에 적용하여 각각의 방법으로 계산된 원거리 필드 패턴을 측정치와 비교함으로써, 개선된 CPFDTD법의 정확도를 검증한다.

• 한국임상수의학회지
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• 제14권2호
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• pp.223-229
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• 1997

This study was carried out to determine the effect of uterus shortening on the pvaries, the length of uterine horn and the recovery of embryos. The length of the shortened uterine horns increased more in part of uterine tip from connecting part for shortening than in base (P<0.05), and collection of embryos was also difficult in gilts because of its narrow pelvis. The embryos collected surgically from gilts with shortened uterine horns were developed into 2~8cells (87.5%) 3days and 4cell~morula (88.9%) 5days after mating.