Non-Contrast Cine Cardiac Magnetic Resonance Derived-Radiomics for the Prediction of Left Ventricular Adverse Remodeling in Patients With ST-Segment Elevation Myocardial Infarction

A Xin,Liu Mingliang,Chen Tong,Chen Feng,Qian Geng,Zhang Ying,Chen Yundai 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.9

Objective: To investigate the predictive value of radiomics features based on cardiac magnetic resonance (CMR) cine images for left ventricular adverse remodeling (LVAR) after acute ST-segment elevation myocardial infarction (STEMI). Materials and Methods: We conducted a retrospective, single-center, cohort study involving 244 patients (random-split into 170 and 74 for training and testing, respectively) having an acute STEMI (88.5% males, 57.0 ± 10.3 years of age) who underwent CMR examination at one week and six months after percutaneous coronary intervention. LVAR was defined as a 20% increase in left ventricular end-diastolic volume 6 months after acute STEMI. Radiomics features were extracted from the oneweek CMR cine images using the least absolute shrinkage and selection operator regression (LASSO) analysis. The predictive performance of the selected features was evaluated using receiver operating characteristic curve analysis and the area under the curve (AUC). Results: Nine radiomics features with non-zero coefficients were included in the LASSO regression of the radiomics score (RAD score). Infarct size (odds ratio [OR]: 1.04 (1.00–1.07); P = 0.031) and RAD score (OR: 3.43 (2.34–5.28); P < 0.001) were independent predictors of LVAR. The RAD score predicted LVAR, with an AUC (95% confidence interval [CI]) of 0.82 (0.75–0.89) in the training set and 0.75 (0.62–0.89) in the testing set. Combining the RAD score with infarct size yielded favorable performance in predicting LVAR, with an AUC of 0.84 (0.72–0.95). Moreover, the addition of the RAD score to the left ventricular ejection fraction (LVEF) significantly increased the AUC from 0.68 (0.52–0.84) to 0.82 (0.70–0.93) (P = 0.018), which was also comparable to the prediction provided by the combined microvascular obstruction, infarct size, and LVEF with an AUC of 0.79 (0.65–0.94) (P = 0.727). Conclusion: Radiomics analysis using non-contrast cine CMR can predict LVAR after STEMI independently and incrementally to LVEF and may provide an alternative to traditional CMR parameters.

Biodegradable cross-linked poly(L-lactide-co-e-caprolactone) networks for ureteral stent formed by gamma irradiation under vacuum

Xiliang Liu,Song Liu,Youkun Fan,Jin Qi,Xin Wang,Wei Bai,Dongliang Chen,Chengdong Xiong,Lifang Zhang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

The poly(L-lactide-co-e-caprolactone) (PLCL) ureteral stent creeps and loses shape stability, increasingthe risk of stent tube dislocation. The rubbery biodegradable cross-linked PLCL networks were preparedthrough gamma irradiation under vacuum in the presence of trimethylolpropane triacrylate (TMPTA),pentaerythritol tetraacrylate (PET4A), and pentaerythritol triacrylate (PETA). At a standard sterilizationdose of 25 kGy, the gel content and network density of PLCL networks increased with increasingcrosslinking agent content (1, 3, 5, 7 wt%), and crosslinking efficiency decreased in the order ofPETA > PET4A > TMPTA. The average molecular weight (Mc ) between two crosslinks ranged from 2000to 105 g/mol. To perform the beneficial semi-interpenetrated polymer network and characterized bythe principle, the networks were processed in several doses (25, 50, 75, 100, and 125 kGy). In place ofthe Charlesby-Pinner equation, the irradiation cross-linking followed the Chen-Liu-Tang equation. ThePLCL network with 7 wt% PETA had a gel fraction of 83%, tensile strength of 34.7 MPa, and tensile setvalue as low as 5%. Furthermore, degradation in vitro was slowed down. Thus, PLCL networks with appropriateelasticity and flexibility, inherent biodegradability, and excellent biocompatibility can provide apromising alternative method for soft tissue repair engineering, such as ureteral stents.

A New Kind of Three-Valued Predicated Logic with Applications to Theory of Programs

Chen Xin Yuan 대한전자공학회 1987 TENCON 87 - Computers and Communications Technolog Vol.- No.-

Social Changes and the Revival of Liberal Education in China since the 1990s

Chen Xin 서울대학교 교육연구소 2004 Asia Pacific Education Review Vol.5 No.1

China’s higher education placed exclusive emphasis on narrowly specialized education and neglected liberal education before the 1990s. However, along with the dramatic social changes since the 1990s, liberal education has revived in China. This paper first examines the characteristics of higher education in China before the 1990s, and then explores the ideas, policies, and specific measures in higher education reform since the 1990s within the larger social context, and thirdly, with a case study on the “liberal education curriculum” introduced by Peking University in 2000, it investigates the ideas, contents and characteristics of liberal education. Finally, it reveals the rationale for the liberal education revival in China.

Utilization of Information from International Observation Trials for the Introduction of New Crops: An Introduction of Azuki Bean Varieties from China to Thailand

Xin, Chen,Volkaert, Hugo,Chatwachirawong, Prasert,Srinives, Peerasak The Korean Society of Crop Science 2008 Journal of crop science and biotechnology Vol.11 No.1

Azuki bean has never been commercially grown in Thailand, due in part to a lack of suitable varieties. A core collection of 114 azuki bean accessions, originally from different parts of China(northern, central, southern) representing the germplasm of Chinese land races, were evaluated in the experimental field of the Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, China from June to October 2004. The same experiment was repeated at Kamphaeng Saen campus of Kasetsart University, Thailand from February to May 2005. Yield, yield components, and agronomic traits were recorded in all accessions in order to identify certain genotypes for further investigation. The statistical parameters that were used as indicators of phenotypic variation were mean, coefficient of variability(CV), correlation coefficient(r), range, mean difference, and phenotypic clustering of the accessions. The results indicated that the azuki bean varieties planted in Kamphaeng Saen were shorter, earlier in growing duration, and lower in plant height, seed yield per plant, 100-seed weight, and pods per plant as compared to when they were grown in China. This discrepancy was caused largely by the combined effect of temperature, rainfall, and day length. The traits that were rather stable in both locations were branches per plant and seeds per pod. Azuki bean varieties from northern China showed higher response to the changing environments compared with those from central and southern China. Some agronomic traits showed high correlation coefficient between the environments in Thailand and China. The CV of agronomic traits in both locations were ranked in descending order as follows: seed yield per plant, pods per plant, branches per plant, plant height, 100-seed weight, seeds per pod, and growing duration. The CV of seeds per pod and branches per plant were almost the same in both locations. Yield per plant in China correlated well(r=0.75) with pods per plant, but not with the other traits. Based on their response to both environments, the azuki bean accessions can be broadly divided into four groups, viz. northern 1, northern 2, central, and southern. This implied that there was more diversity, but probably less stability among the accessions originating from northern China.

On Convergence and Parameter Selection of an Improved Particle Swarm Optimization

Xin Chen,Yangmin Li 대한전기학회 2008 International Journal of Control, Automation, and Vol.6 No.4

This paper proposes an improved particle swarm optimization named PSO with Controllable Random Exploration Velocity (PSO-CREV) behaving an additional exploration behavior. Different from other improvements on PSO, the updating principle of PSO-CREV is constructed in terms of stochastic approximation diagram. Hence a stochastic velocity independent on cognitive and social components of PSO can be added to the updating principle, so that particles have strong exploration ability than those of conventional PSO. The conditions and main behaviors of PSO-CREV are described. Two properties in terms of "divergence before convergence" and "controllable exploration behavior" are presented, which promote the performance of PSO-CREV An experimental method based on a complex test function is proposed by which the proper parameters of PSO-CREV used in practice are figured out, which guarantees the high exploration ability, as well as the convergence rate is concerned. The benchmarks and applications on FCRNN training verify the improvements brought by PSO-CREV.

Management of Primary Hepatic Tuberculosis: A Single Center Experience

( Xin Long ),( Lei Zhang ),( Jianping Zhao ),( Qi Cheng ),( Peng Zhu ),( Zhu Chen ),( Zhiyong Huang ),( Xiaoping Chen ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Primary hepatic tuberculosis is a rare benign disease, without typical manifestation and specific test, which usually contribute to the misdiagnosis of the disease. Therefore, we reviewed eleven cases of primary hepatic tuberculosis in our medical center, in order to find the common features, which might be conductive to improve the diagnostic accuracy of the disease. Methods: Eleven cases of hepatic tuberculosis confirmed by histopathological examination from 2012 to 2017, were collected in our hospital. Clinical features and outcomes were retrospectively analyzed. Results: All the patients were in good condition at admission, including seven male and four female, aging from 18 to 66 years (average 42.7 years). They disclaimed history of pulmonary and any extra-pulmonary tuberculosis. Tumor markers including AFP, CA19-9 and CEA were within the normal range. All the patients, with liver function classified as Child Pugh A, showed no signs of infection. The lesions were presented as hypo-echoic, cystic or solid-cystic in ultrasonography, low density with periphery enhancement on CT scan, and mixed signals on MRI. Two patients were initially diagnosed as liver cancer, two as liver benign tumor, three as hilar tumor, two as liver abscess, and one as others. Five cases underwent partial hepatectomy, two received laparotomy and drainage of the abscess, two experienced laparotomy and liver biopsy, and two with percutaneous needle biopsy. All recovered well after the operation, subsequently received regular treatment of anti-tuberculosis, and completely cured for hepatic tuberculosis. Conclusions: Surgical intervention is an effective way to clarify the diagnosis of asymptomatic primary hepatic tuberculosis.

Smooth Formation Navigation of Multiple Mobile Robots for Avoiding Moving Obstacles

Xin Chen,Yangmin Li 대한전기학회 2006 International Journal of Control, Automation, and Vol.4 No.4

This paper addresses a formation navigation issue for a group of mobile robots passing through an environment with either static or moving obstacles meanwhile keeping a fixed formation shape. Based on Lyapunov function and graph theory, a NN formation control is proposed, which guarantees to maintain a formation if the formation pattern is C<SUP>κ</SUP>, κ≥1. In the process of navigation, the leader can generate a proper trajectory to lead formation and avoid moving obstacles according to the obtained information. An evolutionary computational technique using particle swarm optimization (PSG) is proposed for motion planning so that the formation is kept as C¹ function. The simulation results demonstrate that this algorithm is effective and the experimental studies validate the formation ability of the multiple mobile robots system.

Effect of meridional shape on performance of axial-flow fan

Xin Chen,Linlin Cao,Peng Yan,Peng Wu,Dazhuan Wu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11

In this study, the effect of impeller meridional shape on the performance of axial-flow fan is investigated by CFD method. Three axialflow fan impellers with different meridional shapes are designed. The blade angle, blade stacking condition and other structure factors of the impellers are all remained consistent. The performance curves of the three impellers are calculated and compared. In almost all the interested flowrate range, the impeller W3 with an inverted-isosceles-trapezoid meridional shape and the longer blade camber achieves both the higher pressure rise and the higher efficiency than the other two impellers. A two-stage axial-flow fan designed on basis of W3 is manufactured and tested. Test results show good agreement with the calculated performance curves. Further, analyses of the CFD results are conducted to reveal the reasons for the different performance. A newly-defined Local Euler head (LEH) is introduced to represent the distribution of the major Euler work in the axial-flow fan. And the LEH distributions in the three impellers are obtained. W3 achieves the highest LEH at blade Trailing edge (TE), because it could perform the most Euler work to the fluid with the longest blade camber. Then losses in the impellers are analyzed by means of the entropy generation. Among the losses in impeller, the tip leakage loss and endwall friction loss are dominated at design flowrate. The generation condition of the tip leakage loss shows significant differences among the three impellers. And the whole power loss in impeller of W3 is slightly higher than those of the other two models. However, the power loss difference among the three impellers is negligible. And due to the highest shaft power, the efficiency loss of W3 is the lowest of all.

서비스 산업의 종업원 커뮤니케이션이 소비자의 긍정적 감정과 삶의 질에 미치는 영향

Xin Chen,김규배 한국유통과학회 2018 유통과학연구 Vol.16 No.6

Purpose – There are many antecedences and consequences of the positive emotions of customers. The purpose of this research is to examine how Chinese service companies improve not only the positive emotions of customers but also the quality of life through effective verbal and nonverbal communication. Furthermore, we tried to analyze the moderating role of negative expectancy disconfirmation perceived by customers in those causal relationships among the variables. Research design, data, and methodology – The eight hypotheses were proposed and we tested them empirically in this research. Four hypotheses were about the relationship among communication, positive emotion, trust and quality of life. The other four hypotheses were about the moderating effect of negative expectancy disconfirmation in the causal relationships among four variables such as communication, positive emotion, trust and quality of life. A total of 356 samples who had visited the service companies in China were surveyed and 8 hypotheses were tested by empirical analysis using SPSS and AMOS. Results - The results of this research are as follows. First, positive verbal communication and nonverbal communication of employees in the service company have a positive effects on the positive emotions of customers. Second, positive emotion has a positive effect on the overall quality of life on the customer side as well as the trust on the corporate side. Third, negative expectancy disconfirmation perceived by customers has negative moderating effect in the causal relationship between employees' positive verbal communication and customers' positive emotion, and it also has a negative moderating role in the causal relationship between customers' positive emotion and overall quality of life. Conclusions - Based on these results, there can be such implications as follows. First, managers and employees of service companies can induce positive emotion of customers through effective communication. Second, service companies should try to improve not only the corporate-side performance like trust but also the customer-side performance like quality of life. Third, it will be significant for them to lower the level of negative expectancy disconfirmation for the purpose of improving not only the positive emotions of customers but also the quality of customers' life.