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      • KCI등재

        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.

      • KCI등재

        Preparation of activated carbon spheres and their electrochemical properties as supercapacitor electrode

        An Xin,Xing Guannan,Wang Jing,Tian Yanhong,Liu Yunfang,Wan Qiong 한국탄소학회 2021 Carbon Letters Vol.31 No.4

        The carbon spheres (CSs) synthesized by an ultrasonic-spray pyrolysis method were activated for supercapacitor electrode. There are plenty of cracks on the surface of the activated carbon spheres (ACSs), which expend with increasing the activation temperature and activator dosage. The specifc capacitance of ACSs increases with the activation temperature and activator dosage and reach to maximal value at certain conditions. Importantly, the ACS sample activated at relatively low activation temperature (600 °C) and 7 of mass ratio of KOH to CSs has the highest specifc capacitance (about 209 F g−1 at 50 mA g−1 of current density) and indicates the excellent cycling stability after 1000 consecutive charge–discharge cycles. Furthermore, the graphene sheets could be found in the samples that were activated at 1000 °C. And the electrode prepared by the sample has the very low series resistance because of the excellent conductivity of the formed graphene sheets.

      • KCI등재

        Evaluation of insecticidal activity of the essential oil of Allium chinense G. Don and its major constituents against Liposcelis bostrychophila Badonnel

        Xin Chao Liu,Xiao Nan Lu,Qi Zhi Liu,Zhi Long Liu 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.4

        Water-distilled essential oil from the dried bulbs of Allium chinense (Liliaceae) was analyzed by gaschromatography–mass spectrometry (GC–MS). Eighteen compounds, accounting for 98.4% of the total oil,were identified and the main components of the essential oil of A. chinense were methyl allyl trisulfide(30.7%), dimethyl trisulfide (24.1%), methyl propyl disulfide (12.8%) and dimethyl disulfide (9.6%) followed bymethyl allyl disulfide (3.4%) and methyl propyl trisulfide (3.6%). The essential oil exhibited contact toxicityagainst the booklice (Liposcelis bostrychophila) with an LC50 value of 441.8 μg/cm2 while the two major constituents,dimethyl trisulfide and methyl propyl disulfide had LC50 values of 153.0 μg/cm2 and 738.0 μg/cm2 againstthe booklice, respectively. The essential oil of A. chinense possessed strong fumigant toxicity against the booklicewith an LC50 value of 186.5 μg/l while methyl allyl trisulfide (LC50=90.4 μg/l) and dimethyl trisulfide (LC50=114.2 μg/l) exhibited stronger fumigant toxicity than methyl propyl disulfide (LC50= 243.4 μg/l) and dimethyldisulfide (LC50= 340.8 μg/l) against the booklice. The results indicated that the essential oil and itsmajor constituentshave potential for development into natural insecticides or fumigants for control of insects in stored grains.

      • WILL STRONG RETAILERS ACQUIRE BETTER PROCUMENT PERFORMANCE?: ANALYSIS BASED ON THE MEDIATING EFFECT OF THE QUALITY OF RETAILER-SUPPLIER RELATIONSHIP

        Wenchao Liu,Rupan Sun,Xin Xin,Lihui Sun 글로벌지식마케팅경영학회 2016 Global Marketing Conference Vol.2016 No.7

        Due to the continuous development of international retailers in the Chinese market, and the merger and reorganization among Chinese retailers in recent years, the degree of concentration of the Chinese retail industry has been increasing, and the scale of retailers has been expanding. It is suggested by the report China Powers of Retailing 2014 that an increasing number of large-scale retail groups have been formed in the Chinese retail industry. In large and medium-sized cities in China, such large-scale supermarkets as Wal-Mart, Carrefour and RT-Mart have controlled most market shares of food and daily necessities. And large-scale household appliance chains, such as Gome and Suning, have controlled most market shares of home appliance. Due to the advantage of scale and brand of large-scale retailers, these retailers have gradually occupied a leading role in the supply chain, and formed buyer monopoly power and countervailing power. Intuitively speaking, retailers can acquire obvious advantages in procurement activities, no matter it is the buyer monopoly power or countervailing power that is being utilized. And the advantages are beneficial to the improvement of retailers’ procurement performance. However, it is pointed out by a number of scholars’ research that buyer power’s influence on retail enterprises’ performance is quite complicated. Whether buyer power can improve economic efficiency depends on the quality of retailer-supplier relationship. The quality of the relationships between retailers and suppliers exerts direct influence on the stability, durability and equity of the trade. In the long term, the reinforcement of buyer power will probably exert adverse influence on the suppliers and retailers. By imposing influence on suppliers with buyer power, retailers will cause twisted competition and prifit shrinkage to suppliers in the upstream market. As a result, the quantity of suppliers will be decreased, which will be disadvantageous to the selection of retailers and affect retailers’ utilization of their negotiating advantage. In the meanwhile, by imposing special prices and discounts, collecting extra charges and signing exclusive agreement with suppliers, retailers will lead to suppliers’ impaired benefit. It will further affect the quality of the retailer-supplierrelationship and ultimately exert adverse influence on both parties’ long-term earnings. In the existing research, few scholars have thoroughly discussed the influence of retailers’ buyer power on the quality of retailer-supplier relationship and retail enterprises’ procurement performance. In addition, different conclusions exist in the analysis of the relationships among the three factors, or between two of them. In order to empirically test the influence of retailers’ buyer power on the quality of retailer-supplier relationship and retail enterprises’ procurement performance, we established the theoretical model of this study in figure 1. The research will help us to cognize the influence of retailers’ buyer power more reasonably, and guide retailers better utilize buyer power, an attempt is made to explore the following questions in this research: 1. Does direct positive influence exist between large-scale retailers’ buyer power and retailers’ procurement performance? 2. Are there any differences in the influence of different types of retailers’ buyer power on retailers’ procurement performance? 3. What influence will large-scale retailers’ buyer power exert on the quality of retailer-supplier relationship? 4. When the quality of retailer-supplier relationship is brought in as a mediating variable, what influence will large-scale retailers’ buyer power exert on retailers’ procurement performance? From the perspective of the relationships among channel members, large-scale retailers in the Chinese market, such as Wal-Mart, Carrefour, RT-Mart, OUYA Supermarket and Vanguard, as well as suppliers of their products are taken as the object of the research. Methods like interview, pre-survey and official survery with questionnaire are adopted to verify different hypotheses in the research. During the indepth interview, twelve respondents are invited respectively to the interview. Seven of them are in charge of large-scale retailers’ procurement, and five of them are salespersons of manufacturers, who supply products to retailers. It can be seen from the result of the interview that the twelve respondents hold different opinions towards the relationships among large-scale retailers’ buyer power, the quality of retailer-supplier relationship and retailers’ procurement performance. In terms of the influence of large-scale retailers’ buyer power on retailers’ procurement performance, some believe that there’s positive influence, some believe there’s negative influence, and some believe the influence should be respectively analyzed according to the degree of buyer power. In terms of the influence of large-scale retailers’ buyer power on the quality of retailer-supplier relationship, some believe large-scale retailers’ buyer power exerts positive influence on the quality of retailer-supplier relationship, some believe it exerts negative influence, and some believe the influence depends on specific circumstances. During the pre-survey with questionnaire, scales of retailers’ buyer power, the quality of retailer-supplier relationship and retailers’ procurement performance are developed on the basis of theoretical overview and interview research. Specifically speaking, the scale of retailers’ buyer power is constituted of two level-1 dimensions (buyer’s monopoly power and countervailing power) and seven level-2 dimensions; the scalerelationship and ultimately exert adverse influence on both parties’ long-term earnings. In the existing research, few scholars have thoroughly discussed the influence of retailers’ buyer power on the quality of retailer-supplier relationship and retail enterprises’ procurement performance. In addition, different conclusions exist in the analysis of the relationships among the three factors, or between two of them. In order to empirically test the influence of retailers’ buyer power on the quality of retailer-supplier relationship and retail enterprises’ procurement performance, we established the theoretical model of this study in figure 1. The research will help us to cognize the influence of retailers’ buyer power more reasonably, and guide retailers better utilize buyer power, an attempt is made to explore the following questions in this research: 1. Does direct positive influence exist between large-scale retailers’ buyer power and retailers’ procurement performance? 2. Are there any differences in the influence of different types of retailers’ buyer power on retailers’ procurement performance? 3. What influence will large-scale retailers’ buyer power exert on the quality of retailer-supplier relationship? 4. When the quality of retailer-supplier relationship is brought in as a mediating variable, what influence will large-scale retailers’ buyer power exert on retailers’ procurement performance? From the perspective of the relationships among channel members, large-scale retailers in the Chinese market, such as Wal-Mart, Carrefour, RT-Mart, OUYA Supermarket and Vanguard, as well as suppliers of their products are taken as the object of the research. Methods like interview, pre-survey and official survery with questionnaire are adopted to verify different hypotheses in the research. During the indepth interview, twelve respondents are invited respectively to the interview. Seven of them are in charge of large-scale retailers’ procurement, and five of them are salespersons of manufacturers, who supply products to retailers. It can be seen from the result of the interview that the twelve respondents hold different opinions towards the relationships among large-scale retailers’ buyer power, the quality of retailer-supplier relationship and retailers’ procurement performance. In terms of the influence of large-scale retailers’ buyer power on retailers’ procurement performance, some believe that there’s positive influence, some believe there’s negative influence, and some believe the influence should be respectively analyzed according to the degree of buyer power. In terms of the influence of large-scale retailers’ buyer power on the quality of retailer-supplier relationship, some believe large-scale retailers’ buyer power exerts positive influence on the quality of retailer-supplier relationship, some believe it exerts negative influence, and some believe the influence depends on specific circumstances. During the pre-survey with questionnaire, scales of retailers’ buyer power, the quality of retailer-supplier relationship and retailers’ procurement performance are developed on the basis of theoretical overview and interview research. Specifically speaking, the scale of retailers’ buyer power is constituted of two level-1 dimensions (buyer’s monopoly power and countervailing power) and seven level-2 dimensions; the scaleof the quality of retailer-supplier relationship is constituted of three level-1 dimensions (cooperation, adaption and relationship atmosphere); the scale of retailers’ procurement performance is constituted of three level-1 dimensions (cost performance, time performance and quality performance of procurement). The questionnaire pre-survey is specific to retailers’ procurement staff and suppliers’ sales personnel respectively. A total of valid 179 questionnaires are collected, among which, 86 are from retailers’ procurement staff and 93 are from suppliers’ sales personnel. Based on the survey data, SPSS and AMOS software are utilized in the analysis of items, reliability and validity of the different scales. Finally, the factor structure of the scale regarding retailers’ buyer power is adjusted, and the scale regarding retailers’ buyer monolopy power is re-designed specially. During the official survey with questionnaire, questionnaires are handed out to retailers’ procurement staff and suppliers’ sales personnel respectively. A total of 340 valid questionnaires are collected, among which, 178 are from retailers’ procurement staff and 162 are from suppliers’ sales personnel. The samples, which are quite representative, are evenly distributed. Based on the survey data, SPSS and AMOS software are utilized to further analyze the reliability and validity of the different appraisal scales. Finally, the various hypotheses in the research are tested by causual steps of regression analysis with SPSS. After relatively complicated and elaborate statistical analysis, most of the hypotheses are supported, some are partially supported, and only one is not supported. One of the mediating effect analysis results is show in table 1 and figure 2. Based on direct regression analysis, we can get some important results: First of all, the hypothesis that retailers’ buyer power will overally exert positive influence on retailer enterprises’ procurement performance is supported, but the hypothesis that retailers’ buyer monopoly power and countervailing power will exert positive influence on retailer enterprises’ procurement performance is partially supported. Secondly, the hypothesis that retailers’ buyer power will overally exert negative influence on the quality of retailer-supplier relationship is not supported, and the hypothesis that retailers’ buyer monopoly power will exert negative influence on the quality of retailer-supplier relationship and the dimension is partially supported, and the hypothesis that retailers’ buyer countervailing power will exert positive influence on the quality of retailer-supplier relationship and the dimension is supported. Thirdly, the hypothesis that the quality of retailer-supplier relationship, as well as the dimensions (cooperation and relationship atmosphere) will overally exert positive influence on retailer enterprises’ procurement performance is supported, and the hypothesis that the dimension---the adaptation of the quality of retailer-supplier relationship will exert positive influence on retail enterprises’ procurement performance is only partially supported. Based on causual steps of regression analysis for the mediating effect, we can also get some important results: First of all, the relationship quality plays a complete intermediary role between the retailer’s buyer power and the procurement performance. Secondly, the relationship quality plays a complete intermediary role between the r retailers’ buyer monopoly power and the procurement performance. Thirdly, the relationship quality plays a complete intermediary role between the r retailers’ buyer countervailing power and the procurement performance.Some inspirations are achieved from the research. First of all, basically speaking, the direct influence of retailers’ buyer power on retail enterprises’ procurement performance is significantly positive. Secondly, the influence of retailers’ buyer power on the quality of retailer-supplier relationship is relatively complicated. Thirdly, basically speaking, the influence of the quality of retailer-supplier relationship on retail enterprises’ procurement performance is significantly positive. Fourthly, after the quality of retailer-supplier relationship is brought in as a mediating variable, the influence of retailers’ buyer power on retail enterprises’ procurement performance depends on the specific condition of the retailer-supplier relationship.

      • KCI등재

        Research on the Attenuation of Blast Wave by Groups of Filled Cracks in Surrounding Rock of Cavern

        Xin Liu,Hong-fa Xu,Peng-xian Fan,Jian-nan Zhou,Han-sheng Geng,Jia-quan Mo,Tao-lin Zhang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.7

        This study introduces an approach for constructing groups of filled cracks in the surroundingrock to achieve anti-blasting and wave elimination protection for underground caverns. Toverify the attenuation effect of the explosion wave by the filled cracks, two models, a no-crackmodel, and a filled-crack model, were constructed using a certain proportion of analoguematerials based on the similarity theory. With the implementation of small equivalentexplosion conditions, the peak pressure of the surrounding rock of the cavern and thevibration acceleration of the cavern wall under different explosion conditions were measured. To accurately judge the attenuation efficiency of the filled cracks, the peak pressure attenuationpercentages between different measuring points were calculated. Furthermore, thecorresponding numerical simulation analysis process was performed according to the testconditions. The results show that not only the peak pressure attenuation percentages, but alsothe value of vibration acceleration, were significantly reduced due to the existence of filledcracks in the model. This indicates that filled cracks in the surrounding rock of the cavern caneffectively attenuate the peak pressure and vibration acceleration caused by the explosionwave, thereby achieving the protection engineering goal of anti-explosion and wave elimination.

      • KCI등재

        Study on the transition wavelengths and oscillator strengths of the 1s2n′g–1s2nh state of the Li-like system

        Liu Xin,Zhang Jingchao 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.82 No.2

        In this paper, the spectral properties of 1s2 n′g–1s2 nh states of Li-like ions with larger atomic numbers (Z=21–32) are studied. The transition wavelengths of 1s2 5g–1s2 nh states from Sc XIX to Ge XXX are calculated. The dipole transition oscillator strengths of 1s2 n′g–1s2 nh confguration for Li-like ions under the three specifcations of length, velocity, and acceleration have been obtained. It is found that the three simulation results obtained are very consistent. For the transition of 1s2 5g–1s2 nh state, the dipole transition length oscillator strengths basically remain unchanged with increasing atomic number. The value of the transition oscillator strengths under the same Rydberg sequence decreases with increasing main quantum number n of the fnal state, and gradually tends to zero. Thus, the theoretical calculation of the oscillator strengths of the Li-like sequence with a higher atomic number in the entire energy threshold range is realized.

      • KCI등재

        Progress in Adsorption-Enhanced Hydrogenation of CO2 on Layered Double Hydroxide (LDH) Derived Catalysts

        Xin Fang,Chuang Chen,He Jia,Yingnan Li,Jian Liu,Yisong Wang,Yanli Song,Tao Du,Liying Liu 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.95 No.-

        It is acknowledged as a promising strategy to reduce excessive CO2 emissions by catalytic conversion tovalue-added chemicals, in which layered double hydroxide (LDH) derived catalysts play essential roles. Inthe present review, latest progresses were summarized to gain insights on this issue. LDH-derivedcatalysts can be prepared via various methods and possess favorable characteristics of reversibletopotactic transformation for further development. Compared to conventional catalysts, they showspecific advantages in specific surface area, metal element dispersion and active site distribution. Despiteof distinguished LDH-derived catalysts applied in CO2 reduction reactions to methane, methanol,hydrocarbons, etc., state-of-art LDH-derived catalysts consisted of catalyst-adsorbent synergistic systemare recently constructed to employ the surface CO2 adsorption boundary layer to increase the CO2 partialpressure near active sites for hydrogenation. The overall catalytic performance is thus promoteddramatically. Accordingly, the strategy of adsorption-enhanced hydrogenation is expected to facilitatethe industrialization of CO2 hydrogenation and is instructive for catalyst design in future.

      • Short-course Versus Long-course Preoperative Radiotherapy plus Delayed Surgery in the Treatment of Rectal Cancer: a Meta-analysis

        Liu, Shi-Xin,Zhou, Zhi-Rui,Chen, Ling-Xiao,Yang, Yong-Jing,Hu, Zhi-De,Zhang, Tian-Song Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.14

        Background: Short-course preoperative radiation (SCRT) with delayed surgery was found to increase pathologic complete response (pCR) rates in several trials. However, there was no clear answer on whether SCRT or long-course chemo-radiotherapy (LCRT) is more effective. Therefore we conducted this meta-analysis to evaluate the safety and efficacy of SCRT versus LCRT, both with delayed surgery, for treatment of rectal cancer. Materials and Methods: The literature was searched from PubMed, EMBASE, Web of Science, Cochrane Library and clinicaltrials.gov up to November, 2014. Quality of the randomized controlled trials (RCTs) was evaluated according to the Cochrane's risk of bias tool of RCT. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to rate the level of evidence. Review Manager 5.3 was employed for statistical analysis. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated. Results: Three RCTs, with a total of 357 rectal cancer patients, were included in this systematic review. Metaanalysis results demonstrated there were no significantly differences in sphincter preservation rate, local recurrence rate, grade 3~4 acute toxicity, R0 resection rate and downstaging rate. Compared with SCRT, LCRT was associated with significant increase in the pCR rate [RR=0.49, 95%CI (0.31, 0.78), P=0.003]. Conclusions: In terms of sphincter preservation rate, local recurrence rate, grade 3~4 acute toxicity, R0 resection rate and downstaging rate, SCRT with delayed surgery is as effective as LCRT with delayed surgery for management of rectal cancer. LCRT significantly increased pCR rate compared with SCRT. Due to risk of bias and imprecision, further multi-center large sample RCTs were needed to confirm this conclusion.

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