• Applied Microscopy
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• v.34 no.2
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• pp.145-157
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• 2004

The aim of the present study was to examine in detail, both at light and electron microscopical levels, the morphological variations in ameloblast of the fetal rat incisor enamel organ. Rats were started on distilled water at the beginning of pregnancy. The pups were sacrificed 11 days after delivery and animals were perfused intravascularly with glutaraldehyde and the incisors were removed. To examine on the ultrastructure of the ameloblast, the study employed primary light microscopy but electron microscopy was used to clarify some of the light microscopic finding. Longitudinal sections through the incisors of the rat show a continuous layer of ameloblasts on the labial surface of the tooth. This layer contains the entire sequence of developmental stages in enamel production. The ameloblast layer was divided into three main zones: 1) Presecretory zone, region of ameloblasts facing pulp. 2) Secretory zone, region of inner and outer enamel secretion. 3) Maturation zone, region of reduced ameloblasts. In particularly, the present study has shown that two distinctively different types of ameloblasts appear in the enamel organ during enamel maturation in the rat incisor. These two types have been designated ruffle-ended ameloblasts (rAB) and smooth-ended ameloblasts (sAB). The fluoride produces marked alteration in the fine structure of ameloblast from teeth of young rats, such as large confluent distensions of the endoplasmic reticulum and swelling of isolated mitochondria. This experimental data suggested that exposure prolonged of animal to high level of fluoride appears to induce a few dramatic changes in the normal appositional growth and initial mineralization of enamel created during amelogenesis.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.368-377
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• 2017

This study investigated the possibility of application of the recently introduced cylindrical paper pot seedlings in hot pepper (Capsicum annuum L.) cultivation. The seedling growth, initial rooting after planting and accumulated fruit yield were investigated with the treatments of tray type (paper pot and plug) as a main factor, tray cell number (40 cell and 50 cell) as a sub-factor, and fertigation method (continuous fertigation and fertigation after 35 days sowing) as a sub-sub factor, respectively. The growth of pepper seedlings was significantly affected by tray type and fertigation method showing the highest value at 50 cell plug tray with continuous fertigation, and the effect of fertigation was greater than that of trays. 'Cheongyang', 'Daekwonseoneon' and 'Longgreenmat' cultivar showed all the same pattern in seedling growth. These three-cultivar seedlings were planted in plastic house and in open field in Jeonju area, respectively, and another 'Daekwonseoneon' seedlings raised Yeongyang local area was also planted at the same area. There was no difference in the rooting of 'Cheongyang' pepper at 2 weeks after planting in plastic house. The accumulated fruit weight was not significantly different between paper pot seedlings and plug seedlings in three cultivar grown in plastic house. However, that of 'Cheongyang' pepper showed higher at paper pot seedlings than plug seedlings and the other two cultivar were higher at plug seedlings in open field. 'Daekwonseoneon' pepper yield grown in open field in 'Yeongyang' area was not significant between paper pot seedlings and plug seedlings. In conclusion, the pattern of seedlings growth grown in the cylindrical paper pot was the same as those of the conventional plug seedlings and also fruit yield was similar between paper pot seedlings and plug seedlings even though minute difference among cultivars. These results suggest that pepper seedlings grown in paper pot should be highly applicable to pepper cultivation.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.227-237
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• 1999

As the interface bonding phenomenon between the matrix and the reinforcements has a large effect on the mechanical properties of MMCs, a sugestion of the strength analysis technique considering the residual stress and the interface bonding phenomenon is very important for the design of pans and the estimation of fatigue behavior. In this paper the three dimensional finite element anaysis is performed during the elasto-plastic deformation of the particulate reinforced metal matrix composites. It was analyzed with the volume fractions in view of microscale. Bonding strength. interface separation and matrix void growth between the matrix and the reinforcements will be predicted on deformation under tensile loading. An interface seperation is estimated by the fracture criterion which is a critical value of generalized plastic work per unit volume. The shape of the reinforcement is assumed to be a perfect sphere. And the type of the reinforcement distribution is assumed as FCC array. The thermal residual stress in MMCs is induced by the heat treatment. It is included at the simulation as an initial residual stress. The element birth and death method of the ANSYS program is used for the estimation of the interface bonding strength, void generation and propagation. It is assumed that the fracture in the matrix region begin to occur under the external loading when the plastic work per unit volume is equal to the critical value. The fracture strain will be defined. The experimental data of the extruded $SiC_p$>/606l Al composites are compared with the theoretical results.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.254-261
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• 2000

Since callus distraction technique was applied clinically for the correction of dentofacial deformity to the patients with hemifacial dysplasia by McCarthy in 1992, many surgeons have tried to apply this method to the maxillofacial region. But this technique has some drawbacks. One of the disadvantages of this technique is extensive scar formation in the facial area, which is a sequelae of extraoral approach for supraperiosteal dissection of the periosteum overlying the mandible. Recently, we have made an effort to perform this technique through intraoral approaches to prevent scar formation on the submandibular area and modified the design of the osteotomy, that is step osteotomy technique, to increase the raw bone surface on both osteotomized segments. The rationale for the application of this step osteotomy technique is to increase the amount of regenerated bone and the length of distraction, to avoid damage of inferior alveolar neurovascular bundle, and to increase initial stability of the splitted segments. Step osteotomy procedure can be done with fine micro-osteotomy saw through subperiosteal tunneling. Extraoral pins should be inserted before making the osteotomy. Since 1994 we have applied this technique at 8 sites In 5 patients with mandibular deficiencies: 2 cases of hemifacial microsomia, 1 case of developmental facial asymmetry and 2 cases of mandibular bony defect. Mandibular elongation have been achieved from 12 to 20mm in length. 1 out of 8 site, we experienced non-union in the case of mandibular body defect. Some skeletal relapse and growth retardation phenomenon have been observed in some cases with the longest follow-up of 48 months.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6541-6544
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• 2015

Background: Laryngeal malignancy is a common malignancy of the head and neck region. Affected patients usually present with features that are characteristic of certain subsites. The larynx is oncologically divided into three: supraglottis, glottis and subglottis. Studies from Western countries have shown that the glottis is the commonest subsite to harbour laryngeal malignancy. However, the supraglottis has been reported to be the commonest subsite in developing countries, including examples in the Indian subcontinent. To our knowledge, no study has been carried out in western Nepal about the epidemiology of laryngeal cancer to date. The purpose of this study was to analyse the epidemiology of laryngeal cancer in relation to its risk factors, age distribution,and preferred subsites and to see if there is any recent change in the subsite wise distribution of laryngeal malignancy in western Nepal. Materials and Methods: Patients of all ages and both sexes with suspected laryngeal malignancy were enrolled in the initial study. Detailed history taking and clinical examination was performed to find out the involved subsite in relation to the clinical features. Direct laryngoscopy was performed to further confirm the subsite and to take biopsy from the growth under general anesthesia. After confirmation of malignancy from the biopsy report, patients were finally included in the study. Data were analysed and observations were made to find out the distribution of laryngeal malignancy in different subsites. Results: The supraglottic larynx was the commonest subsite to harbor laryngeal malignancy. Smoking and alcohol were found to be the common risk factors. The mean age of the patients was in their sixties. Conclusions: Laryngeal malignancy is common in elderly individuals. Supraglottic laryngeal malignancy is the commonest laryngeal malignancy in people who smoke and drink alcohol in Nepal. Avoidance of alcohol use and smoking will be a milestone to reduce the incidence of laryngeal cancers and associated mortality.

• Journal of Forest and Environmental Science
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• v.34 no.4
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• pp.338-351
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• 2018

This study was conducted in a long-term experimental forest in the central hardwoods region of southwestern Michigan to retrospectively examine the role of past forest management practices and climate on red oak (Quercus rubra L.) productivity. Initially, in 1971, plots within the experimental forest were treated separately with a clearcut and shelterwood regeneration harvest in an attempt to increase red oak regeneration. From 1987-1989, a new study was initiated within a portion of the clearcut and shelterwood plots to evaluate the effectiveness of additional oak crop tree release using mechanical and chemical applications. Cumulative diameter and mortality rates of 719 red oaks were monitored across the four silvicultural treatments: Clearcut-A (clearcut without additional release treatment), Clearcut-B (clearcut with additional release treatment), Shelterwood-A (shelterwood without additional release), and Shelterwood-B (shelterwood with additional release) plus an untreated control. Increment cores were obtained from red oak trees and neighboring competitor species. Tree-ring analyses (dendrochronology) were applied to examine the effect of these silvicultural treatments and climatic factors (temperature and precipitation) on red oak productivity. The results indicated that crop tree release following a clearcut or shelterwood harvest reduced mortality rates and thus increased survival of red oak. Red oak in control plots or plots only receiving the initial regeneration harvesting treatment and no additional competition release were negatively affected by climatic stress, which included summer moisture stress. In contrast, red oak in plots that received the competition release treatment from shade tolerant tree species not only had higher tree level productivity (i.e., tree basal area) and lower mortality rates, but were also relatively more resilient to climatic stress by showing limited or no associations between climate and growth.

• Journal of the Korean Magnetics Society
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• v.12 no.4
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• pp.132-136
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• 2002

Enhancement of crystallinity and exchange bias characteristics for NiFe/FeMn/NiFe trilayer with Si buffer layer fabricated by ion-beam deposition were examined. A Si buffer layer promoted (111) texture of fcc crystallities in the initial growth region of NiFe layer deposited on it. FeMn layers deposited on Si/NiFe bilayer exhibited excellent (111) crystal texture. The antiferromagnetic FeMn layer between top and bottom NiFe films with the buffer Si 50 ${\AA}$-thick induced a large exchange coupling field Hex with a different dependence. It was found that H$\sub$ex/ of the bottom and top NiFe films with Si buffer layer revealed large value of about 110 Oe and 300 Oe, respectively. In the comparison of two Ta and Si buffer layers, the NiFe/FeMn/NiFe trilayer with Si could possess larger exchange coupling field and higher crystallinity.

• Journal of Energy Engineering
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• v.2 no.2
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• pp.179-186
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• 1993

Heat pipes. applied to a flat plate solar collector, have a long and slender configuration with relatively low heat flux in the evaporator section. Such a heat pipe has a tendency to build-up a liquid pool at the lower part of the evaporator section. and at this pool occurs such complicated phenomena of evaporation and fluid dynamics as superheat, sudden generation of bubble, its likely explosive growth process and flooding, etc. In the present study. we tried to solve these problems by means of adjusting two principal design parameters, the liquid inventory and the installation region of the wick, using 4 heat pipes and 3 thermospheres. The corresponding results can be summarized as follows$\^$1)/. The effective thermal conductances of the heat pipe was greatly improved by eliminating the wick in the adiabatic and condenser sections$\^$2)/. The liquid inventory should be increased by about 40% larger than what is saturated the wick$\^$3)/. In the evaporator section the wick has a favorable effect to reduce both unstable operation by intermittent occurrence of nucleate boiling and response time at the initial start-up process.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.37.1-37.7
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• 2018

Background: Fibrous dysplasia (FD) is characterized by the replacement of normal bone by abnormal fibro-osseous connective tissue and typically treated with surgical contouring of the dysplastic bone. When dysplastic lesions involve occlusion, not only is surgical debulking needed, orthognathic surgery for correction of dentofacial deformity is mandatory. However, the long-term stability of osteotomized, dysplastic bone segments is a major concern because of insufficient screw-to-bone engagement during surgery and the risk of FD lesion re-growth. Case presentation: This case report reviewed two patients with non-syndromic FD that presented with maxillary occlusal canting and facial asymmetry. Le Fort I osteotomy with recontouring of the dysplastic zygomaticomaxillary region had been performed. The stability of osseous segments were favorable. However, dysplastic, newly formed bone covered the previous plate fixation site and mild bony expansion was observed, which did not influence the facial profile. Including the current cases, 15 cases of orthognathic surgery for FD with dentition have been reported in the literature. Conclusion: The results showed that osteotomy did not appear to significantly reduce the long-term stability of the initial fixation insufficiency of the screw to the dysplastic bone. However, based on our results and those of the others, long-term follow-up and monitoring are needed, even in cases where the osteotomized segment shows stable results.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.544-546
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• 2014

A 1.5-year-old, female domestic rabbit was diagnosed with uterine torsion accompanying hydrometra of the right uterine horn and pyometra of the left horn. The exploratory laparotomy revealed the torsion of bilateral uterine horns in the region of the uterine cervix. No growth was detected in fluid collected from the right horn of the uterus; however, Gram-positive micrococcus and bacilli were cultured from the left horn. The pathophysiology of the simultaneous occurrence of these disorders was suspected considering that abdominal distension progressed over 4 months and the rabbit's condition deteriorated abruptly within 2 days, hydrometra was the initial disease and then infection to the left uterine horn and torsion developed later due to the large volume of fluid within the uterus. This report is the first case showing uterine torsion accompanying hydrometra and pyometra in each uterine horn.