The synthesis of dextran from rice hydrolysates using Gluconobacter oxydans KACC 19357 bioconversion (Gluconobacter oxydans 생물전환을 통한 쌀 가수분해물 유래 dextran 합성)
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- Food Science and Preservation
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- v.31 no.1
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- pp.149-160
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- 2024
Dextran is a glucose homo-polysaccharide with a predominantly α-1,6 glycosidic linkage of microbial source and is known to be produced primarily by lactic acid bacteria. However, it can also be obtained through the dextran dextrinase of acetic acid bacteria (Gluconobacter oxydans). The dextrin-based dextran was obtained from rice starch using G. oxydans fermentation of rice hydrolysate, and its properties were studied. Both dextrin- and rice hydrolysate-added media maintained the OD value of 6 after 20 h of incubation with acetic acid bacteria, and the gel permeation chromatography (GPC) analysis of the supernatant after 72 h of incubation confirmed that a polymeric material with DP of 480 and 405, which was different from the composition of the substrate in the medium, was produced. The glucose linkage pattern of the polysaccharide was confirmed using the proton nuclear magnetic resonance (1H-NMR) and the increased α-1,4:α-1,6 bond ratio from 0.23 and 0.13 to 1:2.37 and 1:4.4, respectively, indicating that the main bonds were converted to α-1,6 bonds. The treatment of dextrin with a rat-derived alpha-glucosidase digestive enzyme resulted in a slow release of glucose, suggesting that rice hydrolysate can be converted to dextran using acetic acid bacteria with glycosyltransferase activity to produce high-value bio-materials with slowly digestible properties.
Purpose To evaluate the pattern of use and the perception of digital breast tomosynthesis (DBT) among Korean breast radiologists. Materials and Methods From March 22 to 29, 2021, an online survey comprising 27 questions was sent to members of the Korean Society of Breast Imaging. Questions related to practice characteristics, utilization and perception of DBT, and research interests. Results were analyzed based on factors using logistic regression. Results Overall, 120 of 257 members responded to the survey (response rate, 46.7%), 67 (55.8%) of whom reported using DBT. The overall satisfaction with DBT was 3.31 (1-5 scale). The most-cited DBT advantages were decreased recall rate (55.8%), increased lesion conspicuity (48.3%), and increased cancer detection (45.8%). The most-cited DBT disadvantages were extra cost for patients (46.7%), insufficient calcification characterization (43.3%), insufficient improvement in diagnostic performance (39.2%), and radiation dose (35.8%). Radiologists reported increased storage requirements and interpretation time for barriers to implementing DBT. Conclusion Further improvement of DBT techniques reflecting feedback from the user's perspective will help increase the acceptance of DBT in Korea.
The purpose of this study is to development and validate kkondae tendency scale. Kkondae tendencies are defined as "a response pattern to others in a way that values authority in social relationships, is self-centered, and does not accept other people's opinions," and the subjects of the study are workers aged 19 or older who act as seniors, seniors, and bosses in the workplace. In Study 1, 65 preliminary questions were produced with 7 factors for the compositional concept of kkondae tendency through literature review, expert interviews, and open questionnaire survey. In Study 2, a preliminary survey was conducted with 65 questions derived from Study 1. Exploratory factor analysis was conducted based on the responses of a total of 395 people, and 22 items for 4 factors were derived. In Study 3, this survey was conducted with 22 questions derived from Study 2. A total of 880 responses were analyzed, and cross-validation verification was conducted by dividing the data into two groups (Group 1 and Group 2). Exploratory factor analysis was conducted on Group 1 (N=429) to derive 19 items with 4 factors. The four factors are authoritarianism(3 items), egocentrism (5 items), inertial thinking (5 itemss), and one-sided communication (6 items). A confirmatory factor analysis was conducted on 19 questions obtained from Group 1 for Group 2 (N = 451), and 19 questions of four factors were accepted due to the good fit of the model. To verify the convergent validity of the Kkondae tendency scale, the correlation with the Kkondae scale was examined, and to verify the criterion-related validity, the relationship between self-reflection, relationship conflict, social connectedness was examined. All were statistically significant, and convergence validity and criterion-related validity were verified. Finally, discussions on the process and results of this study, differences from related measures, academic significance, practical implications, limitations of the study, and future research directions were presented.
Nitrogen is a major and essential macronutrient for plant growth and development. However, excessive nitrogen application can lead to ecological pollution or greenhouse gas emissions, consequently resulting in climate change. In this study, we used 153 genetic resources of rice to evaluate the effects of the levels of nitrogen application on grain yield and yield-related traits. Significant differences were noted in the yield and yield-related traits of genetic resources between two nitrogen application levels, namely, 4.5 kg/10a (NN: normal nitrogen condition) and 9.0 kg/10a (LN: low-nitrogen condition). Among the tested traits, days to heading (DTH), clum length (CL), grain yield per plant (GYP), number of panicles per plant (NPP), and number of spikelets per panicle (NSP) decreased by 1.8 to 17.9% when the nitrogen application levels decreased from NN to LN. The 1,000-grain weight (TWG) and percentage of ripened grain (PRG) increased by 2.6 to 11.2% under these conditions. Based on nitrogen application levels, two-way analysis of variance (ANOVA) demonstrated significant differences in GYP, NPP, and PRG but not in NSP and TGW. NPP exhibited negative correlations with NSP (-0.44) and TGW (-0.44), and TGW displayed a negative correlation with PRG (-0.34), whereas, GYP exhibited a positive correlation with PRG (0.37) and NSP (0.38). A similar pattern was recorded under the LN condition. NPP, TGW, and PRG were clustered as PA (principle axis) 1 under the LN condition by factor analysis. NSP and GYP were clustered as PA (principle axis) 2. These results demonstrated NPP and NSP as the primary factors contributing to the decrease in grain yield under LN conditions. In conclusion, we selected eight genetic resources that exhibited higher GYP under both NN and LN conditions with higher NPP or NSP. These genetic resources can be considered valuable breeding materials for the adaptation of plants to nitrogen deficiency.
Although thymomas are relatively common mediastinal tumors, to date not only has a universal system of pathologic classification not been established but neither has a clearly defined predictable relationship between treatment and prognosis been made. Recently, a new guideline for classification was reported by WHO, and efforts, based on this work, have been made to better define the relationship between treatment and prognostic outcome. In the present study a comparative analysis between the WHO classification and Masaoka stage system with the clinical disease pattern was conducted. Material and Method: A total of 98 patients undergoing complete resection for mediastinal thymoma between Juanuary 1993 and June 2003 were included in the present study. The male female ratio was 48 : 50 and the mean age at operation was
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As social data become into the spotlight, mainstream web search engines provide data indicate how many people searched specific keyword: Web Search Traffic data. Web search traffic information is collection of each crowd that search for specific keyword. In a various area, web search traffic can be used as one of useful variables that represent the attention of common users on specific interests. A lot of studies uses web search traffic data to nowcast or forecast social phenomenon such as epidemic prediction, consumer pattern analysis, product life cycle, financial invest modeling and so on. Also web search traffic data have begun to be applied to predict tourist inbound. Proper demand prediction is needed because tourism is high value-added industry as increasing employment and foreign exchange. Among those tourists, especially Chinese tourists: Youke is continuously growing nowadays, Youke has been largest tourist inbound of Korea tourism for many years and tourism profits per one Youke as well. It is important that research into proper demand prediction approaches of Youke in both public and private sector. Accurate tourism demands prediction is important to efficient decision making in a limited resource. This study suggests improved model that reflects latest issue of society by presented the attention from group of individual. Trip abroad is generally high-involvement activity so that potential tourists likely deep into searching for information about their own trip. Web search traffic data presents tourists' attention in the process of preparation their journey instantaneous and dynamic way. So that this study attempted select key words that potential Chinese tourists likely searched out internet. Baidu-Chinese biggest web search engine that share over 80%- provides users with accessing to web search traffic data. Qualitative interview with potential tourists helps us to understand the information search behavior before a trip and identify the keywords for this study. Selected key words of web search traffic are categorized by how much directly related to "Korean Tourism" in a three levels. Classifying categories helps to find out which keyword can explain Youke inbound demands from close one to far one as distance of category. Web search traffic data of each key words gathered by web crawler developed to crawling web search data onto Baidu Index. Using automatically gathered variable data, linear model is designed by multiple regression analysis for suitable for operational application of decision and policy making because of easiness to explanation about variables' effective relationship. After regression linear models have composed, comparing with model composed traditional variables and model additional input web search traffic data variables to traditional model has conducted by significance and R squared. after comparing performance of models, final model is composed. Final regression model has improved explanation and advantage of real-time immediacy and convenience than traditional model. Furthermore, this study demonstrates system intuitively visualized to general use -Youke Mining solution has several functions of tourist decision making including embed final regression model. Youke Mining solution has algorithm based on data science and well-designed simple interface. In the end this research suggests three significant meanings on theoretical, practical and political aspects. Theoretically, Youke Mining system and the model in this research are the first step on the Youke inbound prediction using interactive and instant variable: web search traffic information represents tourists' attention while prepare their trip. Baidu web search traffic data has more than 80% of web search engine market. Practically, Baidu data could represent attention of the potential tourists who prepare their own tour as real-time. Finally, in political way, designed Chinese tourist demands prediction model based on web search traffic can be used to tourism decision making for efficient managing of resource and optimizing opportunity for successful policy.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
During the period from 2001 to 2005, 29,892 burglaries took place in Korea with the approximate average annual number - 5,978 cases. This study was conducted to analyze the reported burglaries and the result was summarized as follows. There were 8,605 residential invasion burglaries (28.8%) as the most frequent characteristic pattern. The exit was used as the most frequent invasion route for 4,031 invasion burglaries (64.3%), and an unlocked exit door or window was used as the most frequent invasion method for 2,462 invasion burglaries (28.6%). The hours just after midnight (between 00:00 and 04:00) were the most frequent time for invasion burglary to occur. Also, 5,652 burglaries occurred on Wednesday which was twice higher than on Sunday (2,988 burglaries). It was shown that the number of persons injured during burglaries were 260 deaths and 10,610 injuries. The places of the highest occurrence were the street with 10,183 burglaries (34%) and then residential place with 7,527 burglaries (approximately 25%). One-man burglary was the highest complicity: 15,012 offenders (56.1%). The knife was used as the most frequent instrument for 6,498 burglaries (24,3%) what is rare, while no criminal tool or instrument was used for 15,631 burglaries (58.4). During the period from 2001 to 2006, 1,506 burglaries occurred in Daegu and the average annual number was 251 burglaries. Among those,515 residential invasion burglaries (34.2%) took place and the average annual number was approximately 86 cases. The hours just after midnight (between 00:00 and 04:00) were the most frequent time for invasion burglary to occur (194 cases, 37.7%), the place of the highest invasion occurrence was the residential place (259 cases, 50.3%), and the exit was used as the most frequent invasion route (87 cases, 37.7%). An unlocked exit door or window was the most frequent invasion method (65 cases, 25.1%). In addition, pretending to be a delivery man, visitor or following the victim methods were used for 26 burglaries (10%). It is apparent that personal preventive measures against crimes, as well as governmental and social measures, play an important role in preventing burglaries. In particular, based on the analyzed result that an unlocked window or exit door was most frequently used for reported burglaries, it seems that there is a lack of understanding of crime prevention while little effort has been made to prevent crimes. Although everyone knows that locking a door is one of the basic measures to prevent crimes, many people tend to pay little attention to lock a door properly so burglary takes place. This study, therefore, is intended to encourage people to pay more careful attention to crime prevention, in order to help reduce the probability of burglary. With the recent improvement in social understanding of scientific crime investigation, a wide variety of police professions, including crime analysts, crime victim police counselors and coroners, have been prepared to develop the scientific crime investigation and crime analysis. In addition, it is hoped that further this study will contribute to encourage studies on crime prevention to be carried out in the future.