Refolding and Purification of Recombinant Human $Interferon-\gamma$ Expressed as Inclusion Bodies in Escherichia coli Using Size Exclusion Chromatography

Guan Yi-Xin,Pan Hai-Xue,Gao Yong-Gui,Yao Shan-Jing,Cho Man-Gi The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.2

A size exclusion chromatography (SEC) process, in the presence of denaturant in the refolding buffer was developed to refold recombinant human $interferon-\gamma$ ($rhIFN-\gamma$) at a high concentration. The $rhlFN-\gamma$ was overexpressed in E. coli resulting in the formation of inactive inclusion bodies (IBs). The IBs were first solubilized in 8 M urea as the denaturant, and then the refolding process performed by decreasing the urea concentration on the SEC column to suppress protein aggregation. The effects of the urea concentration, protein loading mode and column height during the refolding step were investigated. The combination of the buffer-exchange effect of SEC and a moderate urea concentration in the refolding buffer resulted in an efficient route for producing correctly folded $rhIFN-\gamma$, with protein recovery of $67.1\%$ and specific activity up to $1.2\times10^7\;IU/mg$.

The Impact of Factors FormingEmployee Service Attitude on Service Quality, Customer Satisfaction and Loyalty in the Hotel Industry

Guan Xin,최정길 사람과세계경영학회 2020 Global Business and Finance Review Vol.25 No.3

Purpose: This study investigates the effects of hotel employees’ service attitude on service quality and examines the relationships among hotel employees’ service attitude, service quality, customer satisfaction, and loyalty. Design/methodology/approach: A survey was administered to hotel employees in Tianjin, China. Factor analysis and regression analysis were used to test the effects and the relationships. Findings: Results show that emotional intelligence and role clarity have significant effects on service quality and customer satisfaction. However, job satisfaction does not, which is quite different from previous studies observed other than hotel employees in Tianjin, China. It means job satisfaction for the hotel employee in this region is just a factor of basic requirement to work, not a factor of improving service quality. This study also finds that service quality and customer satisfaction have a significant influence on customer loyalty. Research limitations/implications: This study was limited to hotel employees in Tianjin, China. This study concludes that hotel management needs to be more attentive to employees’ emotional intelligence and role clarity in order to attract or retain loyal customers and keep them satisfied. Originality/value: This study identified the relationship between employees’ service attitude and service quality, customer satisfaction and loyalty. Knowledge of these relationships can guide managers in China’s new hotel market.

Asymptotic and Oscillatory Behavior of Higher Order Nonlinear Neutral Difference Equations

GUAN, XIN-PING ...et al. KYUNGPOOK UNIVERSITY 1999 Kyungpook mathematical journal Vol.39 No.2

The purpose of this paper is to study oscillation and asymptotic behavior of the higher order nonlinear forced neutral difference equations. We obtain a series of sufficient conditions for the oscillation and the asymptotic behavior of solutions of higher order neutral difference equations.

중국인 관광객의 한국 명동 이미지 인지에 관한 연구-네트워크 텍스트 분석을 중심으로

Guan Xin,김영국 사단법인 한국융합기술연구학회 2024 아시아태평양융합연구교류논문지 Vol.10 No.2

온라인 리뷰는 정보 통신 기술의 급속한 발전을 전제로 이미 목적지 이미지를 인지하는 중요한 경로가 되었다. 본 연구에서는 웹 크롤러 기술(Web Crawler Technology)을 반으로 중국인 관광객의 온라인 리뷰를 분석 텍스트로 활용하였다. 명동 이미지에 대한 중국 관광객의 인식을 파악하기 위해 인지-정석 이론을 기반으로 Rost Content Mining6을 분석 소프트웨어로 사용하였다. 고빈도 단어 분석, 시맨틱 네트워크 분석 및 정석 분석이 이루어졌다. 본 연구에서는 웹 크롤러(Web Crawler)를 통한 2019년 1월 1일부터 2023년 9월1일까지, Ctrip, Mafengwo, Tongcheng, Qunar 사이트 중 한국 명동 온라인 리뷰를 선정하여 총 730건의 관광객 리뷰를 작성하였다. 웹 크롤러는 온라인 리뷰 등 방대한 양의웹파일을 특정 웹페이지에서 자동으로 수집하는 기술이다[27]. 주제와 무관하게 중복된 잘못된 정보를 제거한 후 최종적으로 총 668건의 네트워크 리뷰 텍스트를 얻었다. 연구결과에 따르면, 쇼핑 천국은 관광객이 느끼는 명동의 이미지로 레저 오락, 환경 분위기, 관광 시설 및 서비스, 관광 체험 및 평가의 네 가지 차원으로 표현되었다. 그 중 쇼핑은 관광객이 가장 깊이 느끼고 긍정적인 감정이 가장 집중된 카테고리이다. 부정적인 감정은 주로 단일 체험 활동, 낮은 가성비, 많은 사람들이 줄을 서는 등의 측면에서 나타났다. With the rapid development of communication technology, online reviews have become an important channel to obtain the perception of destination image. From this point of views, this current study investigated Chinese tourists’ perception of tourism image in Myeongdong; and Chinese tourists’ overall perception and emotional evaluation of Myeongdong tourism. Also, this study was based on web crawler technology to obtain online reviews of Chinese tourists as an analytical text. To understand the Chinese tourists' perception of Myeongdong destination image, based on cognitive-emotion theory, Rost Content Mining 6 software is used for high-frequency words analysis, semantic analysis and emotion analysis. A total of 730 tourist reviews were posted by online reviews of Myeong-dong in Korea from the Ctrip, Mafengwo, Tongcheng, and Qunar sites between January 1, 2019 and September 1, 2023. After removing redundant and incorrect information unrelated to the topic, a total of 668 network review texts were finally obtained. It is found that shopping paradise is the image of Mingdong perceived by tourists, which is embodied in four dimensions: leisure and entertainment, environmental atmosphere, facilities and services, and experience evaluation. Among them, shopping is the category of tourists' most profound perception and most concentrated positive emotion. The negative feelings are mainly reflected in the aspects of single experience activity, low cost performance, and many people queuing up. Limitations and future research directions of the study were also discussed.

A Day-Ahead Optimization Method of Source–Load Coordination for Power System Using Demand Response and Stackelberg Game

Yuan Xin,Tang Hao,Liu Xin,Zhou Xiang,Guan Jinyu 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

The continuous expansion of renewable energy sources and their ongoing integration into existing power networks, alongside the emergence of new types of loads, has led to signifcant new challenges emerging for power grid source–load coordination scheduling in recent years. To fully harness the demand response (DR) potential of the load side of such systems, this paper proposes an optimal scheduling method based on DR and the Stackelberg game. A Stackelberg game model is established to formulate day-ahead source–load coordinated scheduling problem, taking account of the stochastic dynamic characteristics of the load response process and user electricity consumption satisfaction with electricity consumption. The model is essentially a strongly nonlinear optimization problem, however; thus, to avoid several of the limitations seen in traditional optimization methods, a data-model fusion-driven method is proposed, with electricity prices formulated by the data-driven method used as input for a model-driven method whose output is then used in turn to guide a data-driven formulation of electricity prices. Case studies on IEEE test systems are used to verify the feasibility and accuracy of the proposed method.

Role of MYH Polymorphisms in Sporadic Colorectal Cancer in China: A Case-control, Population-based Study

Yang, Liu,Huang, Xin-En,Xu, Lin,Zhou, Jian-Nong,Yu, Dong-Sheng,Zhou, Xin,Li, Dong-Zheng,Guan, Xin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Purpose: Biallelic germline variants of the 8-hydroxyguanine (8-OG) repair gene MYH have been associated with colorectal neoplasms that display somatic $G:C{\rightarrow}T:A$ transversions. However, the effect of single germline variants has not been widely studied, prompting the present investigation of monoallelic MYH variants and susceptibility to sporadic colorectal cancer (CRC) in a Chinese population. Patients and Methods: Between January 2006 and December 2012, 400 cases of sporadic CRC and 600 age- and sex-matched normal blood donors were screened randomly for 7 potentially pathogenic germline MYH exons using genetic testing technology. Variants of heterozygosity at the MYH locus were assessed in both sporadic cancer patients and healthy controls. Univariate and multivariate analyses were performed to determine risk factors for cancer onset. Results: Five monoallelic single nucleotide polymorphisms (SNPs) were identified in the 7 exon regions of MYH, which were detected in 75 (18.75%) of 400 CRC patients as well as 42 (7%) of 600 normal controls. The region of exon 1 proved to be a linked polymorphic region for the first time, a triple linked variant including exon 1-316 $G{\rightarrow}A$, exon 1-292 $G{\rightarrow}A$ and intron 1+11 $C{\rightarrow}T$, being identified in 13 CRC patients and 2 normal blood donors. A variant of base replacement, intron 10-2 $A{\rightarrow}G$, was identified in the exon 10 region in 21 cases and 7 controls, while a similar type of variant in the exon 13 region, intron 13+12 $C{\rightarrow}T$, was identified in 8 cases and 6 controls. Not the only but a newly missense variant in the present study, p. V463E (Exon 14+74 $T{\rightarrow}A$), was identified in exon 14 in 6 patients and 1 normal control. In exon 16, nt. 1678-80 del GTT with loss of heterozygosity (LOH) was identified in 27 CRC cases and 26 controls. There was no Y165C in exon 7 or G382D in exon 14, the hot-spot variants which have been reported most frequently in Caucasian studies. After univariate analysis and multivariate analysis, the linked variant in exon 1 region (p=0.002), intron 10-2 $A{\rightarrow}G$ (p=0.004) and p. V463E (p=0.036) in the MYH gene were selected as 3 independent risk factors for CRC. Conclusions: According to these results, the linked variant in Exon 1 region, Intron 10-2 $A{\rightarrow}G$ of base replacement and p. V463E of missense variant, the 3 heterozygosity variants of MYH gene in a Chinese population, may relate to the susceptibility to sporadic CRC. Lack of the hot-spot variants of Caucasians in the present study may due to the ethnic difference in MYH gene.

Acidic Pelvic Drainage as a Predictive Factor For Anastomotic Leakage after Surgery for Patients with Rectal Cancer

Yang, Liu,Huang, Xin-En,Xu, Lin,Zhou, Xin,Zhou, Jian-Nong,Yu, Dong-Sheng,Li, Dong-Zheng,Guan, Xin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Purpose: To demonstrate the value of sequential determinations of pelvic drainage in the identification of increased risk of anastomotic leakage (AL) after anterior resection for rectal cancer with a double stapling technique. Patients and Methods: Between January 2004 and December 2011, data for the daily postoperative pH of pelvic drainage fluid in 753 consecutive patients with rectal cancer who initially underwent anterior resection with a double stapling technique were reviewed. All patients experienced a total mesorectal excision. Patients with anastomotic leakage (Group AL, n=57) were compared to patients without leakage (Group nAL, n=696). Patients with perioperatively abdominopelvic implants that were likely to affect pH value (determined at $25^{\circ}C$) other than leakage were excluded. Mean postoperative values were compared. Results: Anastomotic leakage was noted in 57 (7.6%) of 753 patients with rectal cancer. The diagnosis of AL was made between the $6^{th}$ and $12^{th}$ postoperative day (POD; mean $8^{th}$ POD). There was no significance of the daily average values of pH on POD1 & 2 in group AL while a significantly sharp declining mean pH value reached its diagnostic point of AL (p<0.001) on POD3. A cut-off value of 6.978 on the $3^{rd}$ POD maximized the sensitivity (98.7.0%) and specificity (94.7%) in assessing the risk of leakage. Conclusion: According to these results, an early and persistent declining of pH value of pelvic drainage fluid after rectal surgery with anastomosis, is a marker of AL. A cut-off value of 6.798 determined at $25^{\circ}C$ on POD3 maximizes sensitivity and specificity.

Outcomes Based on Risk Assessment of Anastomotic Leakage after Rectal Cancer Surgery

Gong, Jian-Ping,Yang, Liu,Huang, Xin-En,Sun, Bei-Cheng,Zhou, Jian-Nong,Yu, Dong-Sheng,Zhou, Xin,Li, Dong-Zheng,Guan, Xin,Wang, Dong-Feng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Purpose: Anastomotic leakage (AL) is associated with high morbidity and mortality, high reoperation rates, and increased hospital length of stay. Here we investigated the risk factors for AL after anterior resection for rectal cancer with a double stapling technique. Patients and Methods: Data for 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2003 to 2007 were prospectively collected. All patients experienced a total mesorectal excision (TME) operation. Clinical AL was defined as the presence of leakage signs and confirmed by diagnostic work-up according to ICD-9 codes 997.4, 567.22 (abdominopelvic abscess), and 569.81 (fistula of the intestine). Univariate and logistic regression analyses of 20 variables were undertaken to determine risk factors for AL. Survival was analysed using the Cox regression method. Results: AL was noted in 35 (7.6%) of 460 patients with rectal cancer. :Median age of the patients was 65 (50-74) and 161 (35%) were male. The diagnosis of AL was made between the 6th and 12th postoperative day (POD; mean 8th POD). After univariate and multivariate analysis, age (p=0.004), gender (p=0.007), tumor site (p<0.001), preoperative body mass index (EMI) (p<0.001), the reduction of TSGF on 5th POD less than 10U/ml (p=0.044) and the pH value of pelvic dranage less than or equal to 6.978 on 3rd POD (p<0.001) were selected as 6 independent risk factors for AL. It was shown that significant differences in survival of the patients were AL-related (p<0.001), high ASA score related (p=0.036), high-level EMI related (p=0.007) and advanced TNM stage related <p<0.001). Conclusions: AL after anterior resection for rectal carcinoma is related to advanced age, low tumor site, male sex, high preoperative EMI, low pH value of pelvic drainage on POD 3 and a significant reduction of TSGF on POD 5. In addition to their high risk of immediate postoperative morbidity and mortality, AL, worse physical status, severe obesity and advanced TNM stage have similarly negative impact on survival.

Carcinoma Microsatellite Instability Status as a Predictor of Benefit from Fluorouracil-Based Adjuvant Chemotherapy for Stage II Rectal Cancer

Yang, Liu,Sun, Yan,Huang, Xin-En,Yu, Dong-Sheng,Zhou, Jian-Nong,Zhou, Xin,Li, Dong-Zheng,Guan, Xin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.4

Purpose: Rectal cancers with high microsatellite-instable have clinical and pathological features that differentiate them from microsatellite-stable or low-frequency carcinomas, which was studied rarely in stage II rectal cancer, promoting the present investigation of the usefulness of microsatellite-instability status as a predictor of the benefit of adjuvant chemotherapy with fluorouracil in stage II rectal cancer. Patients and Methods: Data of 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2008 to 2012 were retrospectively collected. All patients experienced a total mesorectal excision (TME) operation. Survival analysis were analyzed using the Cox regression method. Results: Five-year rate of disease-free survival (DFS) was noted in 390 (84.8%) of 460 patients with stage II rectal cancer. Of 460 tissue specimens, 97 (21.1%) exhibited high-frequency microsatellite instability. Median age of the patients was 65 (50-71) and 185 (40.2%) were male. After univariate and multivariate analysis, microsatellite instability (p= 0.001), female sex (p<0.05) and fluorouracil-based adjuvant chemotherapy (p<0.001), the 3 factors were attributed to a favorable survival status independently. Among 201 patients who did not receive adjuvant chemotherapy, those cancers displaying high-frequency microsatellite instability had a better 5-year rate of DFS than tumors exhibiting microsatellite stability or low-frequency instability (HR, 13.61 [95% CI, 1.88 to 99.28]; p= 0.010), while in 259 patients who received adjuvant chemotherapy, there was no DFS difference between the two groups (p= 0.145). Furthermore, patients exhibiting microsatellite stability or low-frequency instability who received adjuvant chemotherapy had a better 5-year rate of DFS than patients did not (HR, 5.16 [95% CI, 2.90 to 9.18]; p<0.001), while patients exhibiting high-frequency microsatellite instability were not connected with increased DFS (p= 0.696). It was implied that female patients had better survival than male. Conclusion: Survival status after anterior resection of rectal carcinoma is related to the microsatellite instability status, adjuvant chemotherapy and gender. Fluorouracil-based adjuvant chemotherapy benefits patients of stage II rectal cancer with microsatellite-stable or low microsatellite-instable, but not those with high microsatellite-instable. Additionally, free of adjuvant chemotherapy, carcinomas with high microsatellite-instable have a better 5-year rate of DFS than those with microsatellite-stable or low microsatellite-instable, and female patients have a better survival as well.

Mitochondrial citrate accumulation drives alveolar epithelial cell necroptosis in lipopolysaccharide-induced acute lung injury

Yang Hui-Hui,Jiang Hui-Ling,Tao Jia-Hao,Zhang Chen-Yu,Xiong Jian-Bing,Yang Jin-Tong,Liu Yu-Biao,Zhong Wen-Jing,Guan Xin-Xin,Duan Jia-Xi,Zhang Yan-Feng,Liu Shao-Kun,Jiang Jian-Xin,Zhou Yong,Guan Cha-Xi 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Necroptosis is the major cause of death in alveolar epithelial cells (AECs) during acute lung injury (ALI). Here, we report a previously unrecognized mechanism for necroptosis. We found an accumulation of mitochondrial citrate (citratemt) in lipopolysaccharide (LPS)-treated AECs because of the downregulation of Idh3α and citrate carrier (CIC, also known as Slc25a1). shRNA- or inhibitor–mediated inhibition of Idh3α and Slc25a1 induced citratemt accumulation and necroptosis in vitro. Mice with AEC-specific Idh3α and Slc25a1 deficiency exhibited exacerbated lung injury and AEC necroptosis. Interestingly, the overexpression of Idh3α and Slc25a1 decreased citratemt levels and rescued AECs from necroptosis. Mechanistically, citratemt accumulation induced mitochondrial fission and excessive mitophagy in AECs. Furthermore, citratemt directly interacted with FUN14 domain-containing protein 1 (FUNDC1) and promoted the interaction of FUNDC1 with dynamin-related protein 1 (DRP1), leading to excessive mitophagy-mediated necroptosis and thereby initiating and promoting ALI. Importantly, necroptosis induced by citratemt accumulation was inhibited in FUNDC1-knockout AECs. We show that citratemt accumulation is a novel target for protection against ALI involving necroptosis.