• Parasites, Hosts and Diseases
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• 제60권4호
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• pp.273-279
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• 2022

Laelapinae mites are involved in transmission of microbial diseases between wildlife and humans, with an impact on public health. In this study, 5 mite members in the subfamily Laelapinae (laelapin mites; LM) were morphologically identified by light microscopy, and the phylogenetic relationship of LM was analyzed in combination with the sequence information of part of the LM cytochrome oxidase subunit I (cox1) gene. The morphological identification revealed that 5 mites belonged to the genera Laelaps and Haemolaelaps, respectively. Sequence analysis showed that the ratio of nonsynonymous mutation rate to synonymous mutation rate of LM was less than 1, indicating that the LM cox1 gene had undergone purifying selection. Phylogenetic analysis showed that the Laelapinae is a monophyletic group. The genera Haemolaelaps and Hyperlaelaps did not separated into distinct clades but clustered together with species of the genus Laelaps. Our morphological and molecular analyses to describe the phylogenetic relationships among different genera and species of Laelapinae provide a reference for the improvement and revision of the LM taxonomy system.

• 상하수도학회지
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• 제30권1호
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• pp.19-31
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• 2016

The Saemangeum watershed is required to manage water pollution effectively but the effect of liquid manure (LM) on soil and water quality in the basin is not clearly identified as yet. This study aims at assessing the effect on soil of a rice field and water quality of water bodies near the rice field during rice-crop time period to find out the effect of LM, the effect of rainfall, and the effect of rice-crop environment on soil and water quality by analyzing data of nitrogen components. As a result of the LM distribution, $NO_3-N$ was much higher than other N components in the entire soil layers and it was accelerated by rainfall right after the LM distribution. Compared to chemical fertilizer (CF), LM was slightly affected but still influenced on the surface water quality. During weak rainfall, low nitrogen concentration in topsoil was resulted as NH3-N decreased and Org-N and $NO_3-N$ increased. $NO_3-N$ concentration in the water of irrigation canals increased with time. During intensive rainfall, $NO_3-N$ and Org-N of the soil were measured highly in the submerged condition, while the water quality of the rice field was lower due to flooding into the irrigation canal as well as the growth of the rice plants. Also, total nitrogen was increased more than 7 times and it showed serious water quality deterioration due to LM and excessive fertilizer distribution, and rainfall during all rice-crop processes. The effect of LM on water quality should be studied consistently to provide critical data while considering weather condition, cropping conditions, soil characteristics, and so on.

• Brain Tumor Research and Treatment
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• 제6권2호
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• pp.54-59
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• 2018

Background Leptomeningeal metastasis (LM) is an uncommon, but devastating complication of advanced cancer and has no standard treatment. Herein, we analyzed the clinical characteristics and outcomes of patients with solid tumors who were diagnosed with LM. Methods Between January 2007 and December 2017, we retrospectively analyzed the medical records of patients with solid tumors who were diagnosed with LM. Results A total of 58 patients were enrolled in this study. The median age of patients was 51 years (range, 27-72 years), and 62.1% had a poor Eastern Cooperative Oncology Group (ECOG) performance status (PS) (>2). The common types of primary tumor were breast cancer (39.7%), gastric cancer (25.9%), and non-small cell lung cancer (20.7%). Forty-two patients (72.4%) were diagnosed with LM by MRI of the brain and/or spine and cerebrospinal fluid (CSF) analysis, 14 were diagnosed by CSF analysis alone, and 2 were diagnosed by MRI alone. Treatments for LM were performed in 53 patients (91.4%), and best supportive care was provided for 5 patients (8.6%). Intrathecal chemotherapy, radiotherapy, and systemic chemotherapy were administered in 43 (74.1%), 17 (29.3%), and 24 (41.4%) patients, respectively. The median overall survival of the entire cohort was 2.4 months (95% confidence interval, 1.0-3.7). In the analysis of prognostic factors for survival, a good ECOG PS (${\leq}2$), administration of systemic chemotherapy after LM diagnosis, and a prior history of brain radiation were associated with prolonged survival. Conclusion Although the prognosis of LM in patients with solid tumors is poor, systemic chemotherapy might improve survival in selected patients with a good PS.

• Journal of Chest Surgery
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• 제55권5호
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• pp.397-404
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• 2022

Background: Distant recurrence of esophageal cancer (EC), even after radical resection, is common, and the most frequent site of EC metastasis is the liver. However, a multidisciplinary treatment strategy for postoperative liver metastasis (LM) from EC has yet to be established; in particular, the role of liver-directed therapy (LDT) remains uncertain. We investigated the clinicopathological features and outcomes of patients undergoing post-esophagectomy LM with versus without LDT to explore its therapeutic implications. Methods: Among 624 consecutive patients undergoing R0/R1 esophagectomy for EC, 30 were identified in whom LM had developed as the initial recurrence. Their characteristics were retrospectively reviewed. Results: Six of the 30 subjects underwent LDT for metachronous LM. Five of those 6 also received systemic chemotherapy. A comparison between the 6 LDT and 24 non-LDT cases revealed no significant differences in major clinicopathological and operative factors, except for concurrent metastasis to extrahepatic organs (1/6 vs. 15/24, p=0.044). Twenty-nine of the 30 patients died during the study period, whereas 1 who had received multimodal treatment with LDT remained alive more than 200 months after multiple LM had been detected. Kaplan-Meier analysis for survival after LM demonstrated significantly prolonged survival in LDT cases compared to non-LDT cases treated with systemic chemotherapy alone (p=0.014). Even when the analysis was limited to patients without extrahepatic metastasis, this significant prognostic advantage of LDT was maintained (p=0.047). Conclusion: Multimodal treatment combined with LDT might be beneficial for patients with metachronous LM from EC and should therefore be considered a potential treatment option.

• Journal of Korean Neurosurgical Society
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• 제66권4호
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• pp.465-475
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• 2023

Objective : Our objective is to analyze the occurrence, clinical course and risk factors for glioma patients with leptomeningeal metastasis (LM) according to different metastasis patterns and clinical variables. Methods : We retrospectively reviewed data from 376 World Health Organization (WHO) grade II-IV adult glioma patients who were treated in the National Cancer Center from 2001 to 2020. Patients who underwent surgery at other institutions, those without initial images or those with pathologically unconfirmed cases were excluded. LM was diagnosed based on magnetic resonance imaging (MRI) findings or cerebrospinal fluid (CSF) cytology. The metastasis pattern was categorized as nodular or linear according to the enhancement pattern. Tumor proximity to the CSF space was classified as involved or separated, whereas location of the tumor was dichotomized as midline, for tumors residing in the thalamus, basal ganglia and brainstem, or lateral, for tumors residing in the cerebral and cerebellar hemispheres. Results : A total of 138 patients were enrolled in the study. A total of 44 patients (38%) were diagnosed with LM during a median follow-up of 9 months (range, 0-60). Among the clinical variables, tumor proximity to CSF space, the location of the tumor and the WHO grade were significant factors for LM development in univariate analysis. In multivariate analysis, the midline location of the tumor and WHO grade IV gliomas were the most significant factor for LM development. The hazard ratio was 2.624 for midline located gliomas (95% confidence interval [CI], 1.384-4.974; p=0.003) and 3.008 for WHO grade IV gliomas (95% CI, 1.379-6.561; p=0.006). Conclusion : Midline location and histological grading are an important factor for LM in glioma patients. The proximity to the CSF circulation pathway is also an important factor for WHO grade IV glioma LM. Patients carrying high risks should be followed up more thoroughly.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.909-913
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• 2013

Purpose: The liver is the organ to which colorectal carcinomas (CRCs) most commonly metastasize, and surgical resection has been established as the most effective and potentially curative treatment for CRC with liver metastasis (LM). Therefore, surveillance of LM is vital for improvement of prognosis of CRC patients. In this study, we aimed to explore the potential value of carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA), and marker enzymes in indicating LM with CRC. Methods: Three groups of eligible patients with metastatic cancers were retrospectively included: CRC patients with LM (CRC-LM) or without LM (CRC-NLM), and non-CRC patients with LM (NCRC-LM). All metastatic lesions were identified by CT or MRI. Data on characteristics of the patients, the primary site, the locations of metastasis, CA 19-9, CEA, and biochemical parameters were collected for analysis. Results: A total of 493 patients were retrospectively included. More alcohol consumption was found in CRC-LM than CRC-NLM. Some biochemical enzymes were found to be significantly higher in groups with LM than without (CRC-LM or NCRC-LM v.s CRC-NLM). Both CEA and CA 19-9 were much higher in CRC-LM than CRC-NLM or NCRC-LM. For CRC patients, CA 19-9, ${\gamma}$-glutamyl transpeptidase, CEA and alcohol consumption were identified as independent factors associated with LM. Conclusion: Our analysis suggested the CA 19-9 might be a potential valuable indicator for LM of CRC in the clinic.

• Archives of Plastic Surgery
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• 제43권1호
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• pp.10-18
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• 2016

Background Lymphatic malformation (LM) is a form of congenital vascular malformation with a low incidence. Although LM has been studied, no consensus has emerged regarding its cause or treatment. Methods In this study, we retrospectively evaluated 40 patients who visited our vascular anomalies center for the treatment of cervicofacial LM, which is a common manifestation of LM. The medical records of patients over a period of 12 years were reviewed and analyzed for commonalities regarding the diagnosis and the results of treatment. Results Suspected cervicofacial LM was confirmed through imaging studies. No difference in incidence was observed according to sex, and 73% of patients first presented with symptoms before the age of two years. The left side and the V2-V3 area were most commonly affected. No significant differences in incidence were observed among the macrocystic, microcystic, and combined types of LM. A total of 28 out of 36 patients received sclerotherapy as the first choice of treatment, regardless of the type of lesion. Complete resolution was achieved in only 25% of patients. Conclusions LM is important to confirm the diagnosis early and to choose an appropriate treatment strategy according to the stage of the disease and each individual patient's symptoms. When treatment is delayed or an incorrect treatment is administered, patient discomfort increases as the lesion gradually spreads. Therefore, more so than is the case for most other diseases, a team approach on a case-by-case basis is important for the accurate and appropriate treatment of LM.

• ETRI Journal
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• 제38권3호
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• pp.487-493
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• 2016

Two new methods are proposed for an unsupervised adaptation of a language model (LM) with a single sentence for automatic transcription tasks. At the training phase, training documents are clustered by a method known as Latent Dirichlet allocation (LDA), and then a domain-specific LM is trained for each cluster. At the test phase, an adapted LM is presented as a linear mixture of the now trained domain-specific LMs. Unlike previous adaptation methods, the proposed methods fully utilize a trained LDA model for the estimation of weight values, which are then to be assigned to the now trained domain-specific LMs; therefore, the clustering and weight-estimation algorithms of the trained LDA model are reliable. For the continuous speech recognition benchmark tests, the proposed methods outperform other unsupervised LM adaptation methods based on latent semantic analysis, non-negative matrix factorization, and LDA with n-gram counting.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1270-1274
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• 2003

The objective of this paper is to introduce the standard of evaluation methods and fatigue test for linear motion rolling bearing. In particular, attention well be given to the list of evaluation and fatigue results in this paper. The life of a linear motion rolling bearing is given by the length of distance covered between the connection parts before the first evidence of fatigue develops in the material of one of the raceways of rolling elements. The main factors that contribute to fatigue failures include: Number of load cycles experienced; Range of stress experienced in each load cycle; Mean stress experienced in each toad cycle; Presence of local stress concentrations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.210-210
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• 2000

In this paper, we have investigated the properties of multi-layer perceptron (MLP) for odour patterns classification and concentration estimation simultaneously. When the MLP may be has a fast convergence speed with small error and excellent mapping ability for classification, it can be possible to use for classification and concentration prediction of volatile chemicals simultaneously. However, the conventional MLP, which is back-Propagation of error based on the steepest descent method, was difficult to use for odour classification and concentration estimation simultaneously, because it is slow to converge and may fall into the local minimum. We adapted the Levenberg-Marquardt(LM) algorithm [4,5] having advantages both the steepest descent method and Gauss-Newton method instead of the conventional steepest descent method for the simultaneous classification and concentration estimation of odours. And, We designed the artificial odour sensing system(Electronic Nose) and applied LM-BP algorithm for classification and concentration prediction of VOC gases.