• 대한수학회지
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• 제54권3호
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• pp.987-997
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• 2017

A deterministic model for the spread of pine wilt disease with asymptomatic carrier trees in the host pine population is designed and rigorously analyzed. We have taken four different classes for the trees, namely susceptible, exposed, asymptomatic carrier and infected, and two different classes for the vector population, namely susceptible and infected. A complete global analysis of the model is given, which reveals that the global dynamics of the disease is completely determined by the associated basic reproduction number, denoted by $\mathcal{R}_0$. If $\mathcal{R}_0$ is less than one, the disease-free equilibrium is globally asymptotically stable, and in such a case, the endemic equilibrium does not exist. If $\mathcal{R}_0$ is greater than one, the disease persists and the unique endemic equilibrium is globally asymptotically stable.

• 치과방사선
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• 제18권1호
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• pp.203-212
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• 1988

This study was designed to observe mandibular condyle shape and position in an asymptomatic popular ion. Using Accurad-200 head holder(Denar Corp.) for transcranial radiography of the temporo-mandibular joint region, transcranial radiographs were taken at the centric occlusion and 1 inch mouth opening in 73 males and females who were asymptomatic for TMJ disturbances, had no severe carious or missing teeth, and no history of prosthodontic or orthodontic treatments. Mandibular condyles were classified morphologically at the centric occlusion and evaluated in positional relationship with mandibular fossa and articular eminence at the centric occlusion and 1 inch mouth opening. The results were as follows: 1. In the morphologic classification of mandibular condyle, the convex shape was more prevalent in an asymptomatic population(90.4%), the locally concave shape and wedge shape were 5.5%, 4.1%. 2. At the centric occlusion, the means of joint space were 3.43nm superiorly, 2.17㎜ anteriorly, and 2.61㎜ posteriorly. 3. At the centric occlusion, the mandibular condyles were placed slightly anterior to the center of their fossa. 4. At the 1 inch mouth opening, the mandibular condyles were placed anterior to the articular eminence more than posterior to or below the top of the articular eminence.

• Journal of Korean Neurosurgical Society
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• 제53권2호
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• pp.89-95
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• 2013

Objective : Similar to back pain, neck pain has recently shown to have increasing prevalence. Magnetic resonance imaging (MRI) is useful in identifying the causes of neck pain. However, MRI shows not only pathological lesions but also physiological changes at the same time, and there are few Korean data. The authors have attempted to analyze the prevalence of disc degeneration in highly selective asymptomatic Korean subjects using MRI. Methods : We performed 3 T MRI sagittal scans from C2 to T1 on 102 asymptomatic subjects (50 men and 52 women) who visited our hospital between the ages of 14 and 82 years (mean age 46.3 years). All images were read independently by three observers (two neurosurgeons and one neuroradiologist) who were not given any information about the subjects. We classified grading for cervical disc herniation (HN), annular fissure (AF), and nucleus degeneration (ND), using disc degeneration classification. Results : The prevalence of HN, AF, and ND were 81.0%, 85.9%, and 95.4%, respectively. High prevalence of HN, AF, and ND was shown compared to previous literature. Conclusion : In asymptomatic Korean subjects, the abnormal findings of 3 T MRI showed a high prevalence in HN, AF, and ND. Several factors might play important roles in these results, such as population-specific characters, MRI field strength, and disc degeneration grading system.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1083-1088
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• 2016

Background: Cervical cancer is the second commonest cancer among Indian women and its association with human papilloma virus (HPV) is well established. This preventable cancer accounts for the maximum number of cancer related deaths among rural Indian women. Unlike in developed countries there are no organized cervical cancer screening programmes in India due to lack of resources and manpower. Objective: To detect genital HPV infection using urine samples among asymptomatic rural women in the age group of 18-65 years. Materials and Methods: The study area chosen was Perdoor village in Udupi Taluk, Karnataka State and all the women in the age group of 18-65 years formed the study cohort. A cross sectional study was conducted by house visits and 1,305 women were enrolled in the study. After taking written informed consent a data sheet was filled and early stream random urine samples were collected, transported to a laboratory at 4OC and aliquoted. Samples were tested using nested HPV PCR with PGMY09/11 and GP5+/6+ primers. Positive cases were genotyped by sequence analysis. Results: Study participants included 1,134 sexually active and 171 unmarried women with a mean age at marriage of 22.1 (SD=3.9) years. Study area showed high female literacy rate of 86.6%. Five urine samples tested positive for HPV DNA (0.4%). Conclusions: We found very low genital HPV infection rate among women from monogamous community. This is the first major population based study carried out among asymptomatic rural women to detect genital HPV infectio from Karnataka using urine samples.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8837-8842
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• 2014

Background: Hepatitis C virus (HCV) infection is an important cause of liver cancer in Thailand. The highest prevalence of anti-HCV positive among Thai blood donors is found in the northeastern region. The present analysis of the genotype distribution among anti-HCV positive northeastern-Thai blood donors was conducted to provide a base for the epidemiological pattern of HCV infection in this region. Materials and Methods: A total of 112 HCV seropositive healthy blood donors were randomly selected and tested for the presence of HCV-RNA by RT-PCR. HCV-RNA positive samples were genotyped by direct sequencing at core region genomes and confirmed by phylogenetic analysis. Results: HCV viremia was found in 94.6% (106/112) of HCV seropositive blood donors. There were 3 major genotypes distributed among this population. HCV genotype 3a was the most prevalent (71.7%) followed by genotypes 1a (7.5%), 1b (7.5%), 6i (3.8%), 6f (2.8%) and 6n (1.9%). Conclusions: HCV genotype 3a in asymptomatic infections in northeastern Thailand is significantly higher than other previous reports. Subgenotype 6 prevalence is less than in neighboring countries and distribution patterns differ. The findings are relevant as predictors for using interferon therapy in this population.

• Imaging Science in Dentistry
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• 제36권2호
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• pp.103-109
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• 2006

Purpose : To evaluate position of the mandibular condyle within articular fossa in an asymptomatic population radiographically by a cone beam computed tomography. Materials and Methods : Cone beam computed tomography of 60 temporomandibular joints was performed on 15 males and 15 females with no history of any temporomandibular disorders, or any other orthodontic or prosthodontic treatments. Position of mandibular condyle within articular fossa at centric occlusion was evaluated. A statistical evaluation was done using a SPSS. Results : In the sagittal views, mandibular condyle within articular fossa was posteriorly located at medial and central sections. In the coronal views, mandibular condyle within articular fossa was laterally located at central section. Mandibular condyles in the right and left sides were showed asymmetric positional relationship at medial, central, and lateral sections. Conclusion : Mandibular condyle within articular fossa in an asymptomatic population was observed nonconcentric position in the sagittal and coronal views.

• 농업과학연구
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• 제49권4호
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• pp.881-892
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• 2022

Fire blight in apple and pear orchards, caused by Erwinia amylovora, is a global problem. Ongoing outbreaks have occurred since 2015. In 2020, 744 orchards were infected compared with 43 orchards in 2015 in Korea. When are insufficient. In Korea, all host plants in infected orchards are buried deeply with lime to eradicate the E. amylovora outbreak within a few days. Apple trees with infected trunks and branches and twigs with infected leaves and infected blooms were collected from an apple orchard in Chungju, Chungbuk province, where fire blight occurred in 2020. We used these samples to investigate the population density and internal distribution of E. amylovora on infected branches and twigs during early season infections. Infected branches and twigs were cut at 10 cm intervals from the infected site, and E. amylovora was isolated from tissue lysates to measure population density (colony-forming unit [CFU]·mL^-1). The polymerase chain reaction was performed on genomic DNA using E. amylovora specific primers. Real-time polymerase chain reaction (PCR) was performed to detect E. amylovora in asymptomatic tissue. The objective of these assays was to collect data relevant to the removal of branches from infected trees during early season infection. In infected branches, high densities of greater than 10⁶ CFU·mL^-1 E. amylovora were detected within 20 cm of the infected sites. Low densities ranging from 10² to 10⁶ CFU·mL^-1 E. amylovora were found in asymptomatic tissues at distances of 40 - 75 cm from an infection site.

• Journal of Korean Neurosurgical Society
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• 제53권2호
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• pp.96-101
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• 2013

Objective : The purpose of this study was to analyze the differences of spinopelvic parameters between degenerative spondylolisthesis (DSPL) and isthmic spondylolisthesis (ISPL) patients. Methods : Thirty-four patients with DSPL and 19 patients with ISPL were included in this study. Spinopelvic parameters were evaluated on whole spine X-rays in a standing position. The following spinopelvic parameters were measured : pelvic incidence (PI), sacral slope, pelvic tilt (PT), lumbar lordosis (LL), and sagittal vertical axis from C7 plumb line (SVA). The population of patients was compared with a control population of 30 normal and asymptomatic adults. Results : There were statistically significant differences in LL (p=0.004) and SVA (p=0.005) between the DSPL and ISPL group. The LL of DSPL ($42{\pm}13^{\circ}$) was significantly lower than that of the control group ($48{\pm}11^{\circ}$; p=0.029), but that of ISPL ($55{\pm}6^{\circ}$) was significantly greater than a control group (p=0.004). The SVA of DSPL ($55{\pm}49$ mm) was greater than that of a control group (<40 mm), but that of ISPL ($21{\pm}22$ mm) was within 40 mm as that of a control group. The PT of DSPL ($24{\pm}7^{\circ}$) and ISPL ($21{\pm}7^{\circ}$) was significantly greater than that of a control group ($11{\pm}6^{\circ}$; p=0.000). Conclusion : Both symptomatic DSPL and ISPL patients had a greater PI than that of the asymptomatic control group. In conclusion, DSPL populations are likely to have global sagittal imbalance (high SVA) compared with ISPL populations because of the difference of lumbar lordosis between two groups.

• Clinical and Experimental Pediatrics
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• 제45권12호
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• pp.1540-1545
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• 2002

목 적 : 방광요관역류는 국외의 연구에 의하면 가족력이 중요하며 무증상 형제 자매에서의 방광요관역류 발생빈도가 26-51%의 높은 빈도로 보고되고 있고 역류성 신병증, 소아 고혈압, 만성 신부전으로 진행될 수 있으므로 선별검사의 중요성이 강조되어 왔는데 우리나라 소아에서도 무증상 형제 자매의 방광요관역류 빈도를 조사하여 선별검사의 근거를 제시하고자 본 연구를 시행하였다. 방 법: 인제대학교 의과대학 상계백병원에 내원하여 방광요관역류로 진단받은 환아 중 VCUG 검사에 동의한 28명의 무증상 형제 자매를 대상으로 하였고 방광요관역류 환아의 무증상 형제 자매 중 VUR로 진단받은 형제 자매는 모두 DMSA 신스캔을 시행하였다. 결 과 : VUR로 진단받은 환아는 총 28명이고 남아 14 명, 여아 14 명, 나이는 1개월에서 8년 5개월로 평균 2.7세였다. VCUG 검사에 동의한 무증상 형제 자매는 총 28명으로 남아 17명, 여아 11명, 나이는 2개월에서 7년 5개월로 평균 3.3세였다. VUR로 진단된 환아 28명 중 20례에서 신손상이 있어 전체적으로 71.4%의 신손상의 빈도를 보였다. 무증상 형제 자매 28명 중 VCUG 검사상 VUR로 진단된 형제 자매는 3명으로 10.7%의 VUR 발생빈도를 보였고 DMSA 신스캔 상 이상이 발견된 경우는 1명이였다. 결 론 : 방광요관역류 환아의 무증상 형제 자매에서 역류빈도는 10.7%로 조사되어 방광요관역류의 위험인자로서 가족력이 중요함을 제시해주고 있으며 방광요관역류의 가족선별검사의 근거를 확립하기 위해서 앞으로 더 많은 연구가 시행되어야 하겠다.

• Korean Journal of Radiology
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• 제2권1호
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• pp.8-13
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• 2001

Objective: To determine the incidence and etiologies of celiac axis stenosis in asymptomatic individuals. Materials and Methods: This prospective study involved 400 consecutive patients (male: 319, female: 81) referred to us for celiac arteriography between April and July 1999. When celiac axis branches were opacified by collateral circulation during superior mesenteric arteriography, the presence of celiac axis stenosis was suspected; lateral projection celiac arteriography was performed and the pressure gradient was measured. The indicators used to determine whether or not celiac axis stenosis was significant were luminal narrowing of more than 50% and a resultant pressure gradient of at least 10 mmHg. Its etiology was determined on the basis of angiographic appearances and CT findings. Results: Twenty-nine patients (7.3%) had celiac axis stenosis. The etiology of the condition was extrinsic compression due to the median arcuate ligament in 16 patients (55%) and atherosclerosis in three (10%), while in ten (35%) it was not determined. The incidence of celiac axis stenosis did not vary significantly according to sex, age and the presence of calcified aortic plaque representing atherosclerosis. Conclusion: The incidence of hemodynamically significant celiac axis stenosis in this asymptomatic Korean population was 7.3% and the most important etiology was extrinsic compression by the median arcuate ligament of the diaphragm. Atherosclerosis was only a minor cause of the condition.