The Stability, and Efficacy Against Penicillin-Resistant Enterococcus faecium, of the Plectasin Peptide Efficiently Produced by Escherichia coli

( Xin Chen ),( Yaoan Wen ),( Ling Li ),( Jiawei Shi ),( Zhe Zhu ),( Yuwen Luo ),( Yun Li ),( Rui Chen ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.7

Plectasin, the first defensin extracted from a fungus (the saprophytic ascomycetePseudoplectania nigrella), is attractive as a prospective antimicrobial agent. The purpose of this study was to establish a bacterium-based production system and evaluate the antimicrobial activity of the resulting plectasin. A gene encoding plectasin, with the codon preference ofEscherichia coli, was optimized based on its amino acid sequence, synthesized using genesplicing with overlap extension PCR, and inserted into the expression vector pGEX-4T-1. The fusion protein was expressed in the soluble fraction of E. coli and purified using glutathione Stransferaseaffinity chromatography. Plectasin was cleaved from the fusion protein with thrombin and purified by ultrafiltration. The purified plectasin showed strong, concentrationdependent antimicrobial activity against gram-positive bacteria, including antibiotic-resistant bacteria, especially penicillin-resistant Enterococcus faecium. This antimicrobial activity wasequal to chemically synthesized plectasin and was maintained over a wide range of pH and temperatures. This soluble recombinant expression system in E. coli is effective for producing plectasin at a relatively lower cost, and higher purity and efficiency than prior systems, and might provide a foundation for developing a large-scale production system. Overall, plectasin shows potential as a novel, high-performance, and safe antibiotic for the treatment of refractory diseases caused by drug-resistant bacterial strains.

Helmet CPAP versus Oxygen Therapy in Hypoxemic Acute Respiratory Failure: A Meta-Analysis of Randomized Controlled Trials

Xin Chen,Yuwen Luo,Yan Luo,Yun Li,Luqian Zhou,Zhe Zhu,Yitai Chen,Yuxia Huang 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.4

Purpose: The efficacy of helmet continuous positive airway pressure (CPAP) in hypoxemic acute respiratory failure (hARF) remainsunclear. The aim of this meta-analysis was to critically review studies that investigated the effect of helmet CPAP on gas exchange,mortality, and intubation rate in comparison with standard oxygen therapy. Materials and Methods: We performed a meta-analysis of randomized controlled trials (RCTs) by searching the PubMed, Embase,Cochrane library, OVID, and CBM databases, and the bibliographies of the retrieved articles. Studies that enrolled adults with hARF who were treated with helmet CPAP and measured at least one of the following parameters were included: gas exchange,intubation rate, in-hospital mortality rate. Results: Four studies with 377 subjects met the inclusion criteria and were analyzed. Compared to the standard oxygen therapy, helmet CPAP significantly increased the PaO2/FiO2 [weighted mean difference (WMD)=73.40, 95% confidence interval (95% CI): 43.92 to 102.87, p<0.00001], and decreased the arterial carbon dioxide levels (WMD=-1.92, 95% CI: -3.21 to -0.63, p=0.003), intubationrate [relative risk (RR)=0.21, 95% CI: 0.11 to 0.40, p<0.00001], and in-hospital mortality rate (RR=0.22, 95% CI: 0.09 to 0.50, p=0.0004). Conclusion: The results of this meta-analysis suggest that helmet CPAP improves oxygenation and reduces mortality and intubationrates in hARF. However, the significant clinical and statistical heterogeneity of the literature implies that large RCTs are neededto determine the role of helmet CPAP in different hypoxemic ARF populations.

Mitochondrial Location of Severe Acute Respiratory Syndrome Coronavirus 3b Protein

Yuwen Cong,Xiaoling Yuan,Yajun Shan,Zhenyu Yao,Jianyong Li,Zhenhu Zhao,Jiapei Chen 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.2

Combinatorial Optimization Using FOA and GA in Futures Market Technical Analysis

Yuwen Zhang,Chen Fang 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

This paper presents a combination of the Fruit Fly Optimization Algorithm (FOA) and Genetic Algorithm(GA) for multi-objective combinatorial optimization(MOCO).The goal of the combination is to combine the advantages of FOA for its good ability in fast convergence and GA for its good performance in combinatorial optimization. In the last part of the paper, the new combination method was applied to the combinatorial optimization of futures market technical analysis. It shows good performance in finding a best combination and good suitability when data has been changed.

An Inverted U-shaped Relationship between Information Transparency and Idiosyncratic Risk

Yi Chang Chen,Mao Feng Kao,Hui Cheng Yu,Yuwen Yang,Yixuan Fu 한국유통과학회 2017 KODISA ICBE (International Conference on Business Vol.2017 No.-

Prior literature indicates that the endogeneity problem exists between information transparency and idiosyncratic risk, and that the results of the impact of transparency on risk are still inconclusive. This study attempts to employ a simultaneous equation model to investigate the non-linear relationship between information transparency and idiosyncratic risk. The variables of firm’s information transparency are drawn from the “Annual Report on China’s Companies’ Public Transparency” published by the China Social Science Academic Press. The finding indicates that an inverted U-shaped relationship exists between information transparency and idiosyncratic risk. The empirical result of the non-linear relation not only confirms the disclosure theory that the relationship between information transparency and idiosyncratic risk is negative, but also explains the inconsistent evidence in previous research.

Acid Exposure Time > 6% Might Not Improve the Therapeutic Outcome in Chinese Gastroesophageal Reflux Disease Patients

( Yuqing Lin ),( Yuwen Li ),( Mengya Liang ),( Niandi Tan ),( Mengyu Zhang ),( Songfeng Chen ),( Yinglian Xiao ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2021 Journal of Neurogastroenterology and Motility (JNM Vol.27 No.1

Background/Aims There is less acid burden in Chinese gastroesophageal reflux disease (GERD) patients. However, the Lyon consensus proposed a higher threshold of acid exposure time (AET > 6%) for GERD. The aims are to apply the updated criteria in Chinese GERD patients and clarify its influence on clinical outcome. Methods Patients who were referred for both esophageal high-resolution manometry and 24-hour esophageal pH monitoring due to reflux symptoms were retrospectively screened. Those patients with AET > 4% was included and grouped into either AET 4-6% or AET > 6%. Their manometric profile, reflux profile, and response to proton pump inhibitors (PPIs) were evaluated. Adjunctive evidence proposed in the Lyon consensus was added in patients with AET 4-6% for therapeutic gain. Another group of patients (n = 144) with AET < 4% were included as non-GERD patients. Results In total, 151 patients (102 males) were included with 113 patients AET > 6% (74.9%). GERD patients with AET > 4% were with more male, older patients, and higher body mass index compared with non-GERD patients. Meanwhile, GERD patients were less competent in esophagogastric junction pressure. However, the manometric and reflux profile were similar between patients with AET > 6% and 4-6%. The response rate of PPI therapy was 64.6% and 63.2%, respectively, in groups of AET > 6% and 4-6% (P > 0.05). When adjunctive evidence was added in patients with AET 4-6%, no therapeutic gain was obtained. Conclusions The efficacy of PPI therapy was similar in patients with AET > 6% and 4-6%. The increase of the AET threshold did not influence the clinical outcome of Chinese GERD patients. (J Neurogastroenterol Motil 2021;27:55-62)

Quantum Public-key Cryptosystem without Quantum Channels between Any Two Users using Non-orthogonal States

Xiaoyu Li,Yuwen Chen 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.9

A quantum public-key cryptosystem without quantum channels between any two users using non-orthogonal states is provided in this paper. Every user keeps a set of quantum particles in non-orthogonal states in a key management center (KMC) as the public key while he or she keeps the states of them as the private key. By the help of KMC users can accomplish secret communication and message authentication. The laws of quantum physics guarantee the unconditional security of this cryptosystem. No entangled states or complex quantum operations are needed. On the other hand there are no quantum channels needed to connecting any two users. So the public-key cryptosystem is easier to carry out and more robust in practice.

A LightGBM and XGBoost Learning Method for Postoperative Critical Illness Key Indicators Analysis

( Lei Han ),( Yiziting Zhu ),( Yuwen Chen ),( Guoqiong Huang ),( Bin Yi ) 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.8

Accurate prediction of critical illness is significant for ensuring the lives and health of patients. The selection of indicators affects the real-time capability and accuracy of the prediction for critical illness. However, the diversity and complexity of these indicators make it difficult to find potential connections between them and critical illnesses. For the first time, this study proposes an indicator analysis model to extract key indicators from the preoperative and intraoperative clinical indicators and laboratory results of critical illnesses. In this study, preoperative and intraoperative data of heart failure and respiratory failure are used to verify the model. The proposed model processes the datum and extracts key indicators through four parts. To test the effectiveness of the proposed model, the key indicators are used to predict the two critical illnesses. The classifiers used in the prediction are light gradient boosting machine (LightGBM) and eXtreme Gradient Boosting (XGBoost). The predictive performance using key indicators is better than that using all indicators. In the prediction of heart failure, LightGBM and XGBoost have sensitivities of 0.889 and 0.892, and specificities of 0.939 and 0.937, respectively. For respiratory failure, LightGBM and XGBoost have sensitivities of 0.709 and 0.689, and specificity of 0.936 and 0.940, respectively. The proposed model can effectively analyze the correlation between indicators and postoperative critical illness. The analytical results make it possible to find the key indicators for postoperative critical illnesses. This model is meaningful to assist doctors in extracting key indicators in time and improving the reliability and efficiency of prediction.

Esophagogastric Junction Contractility Integral Reflect the Anti-reflux Barrier Dysfunction in Patients with Gastroesophageal Reflux Disease

( Chenxi Xie ),( Jinhui Wang ),( Yuwen Li ),( Niandi Tan ),( Yi Cui ),( Minhu Chen ),( Yinglian Xiao ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2017 Journal of Neurogastroenterology and Motility (JNM Vol.23 No.1

Background/Aims Anti-reflux barrier dysfunction is one of the primary mechanisms in gastroesophageal reflux disease (GERD) pathogenesis. The esophagogastric junction contractile integral (EGJ-CI) is a new metric adopted to evaluate the EGJ contractility, which implies the antireflux barrier function. The aim of the current study was to validate this new metric in patients with GERD and its correlation with the esophageal acid exposure, as well as the efficacy of proton pump inhibitor treatment. Methods Ninety-eight patients with GERD and 21 healthy controls were included in the study. Upper endoscopy, high-resolution manometry (HRM) and 24-hour multichannel intraluminal impedance-pH monitoring were performed in all patients. Three respiration cycles were chosen at the initial HRM resting frame and the value computed with distal contractile integral tool was then divided by the duration of the cycles to yield EGJ-CI. All the patients were treated with esomeprazole 20 mg twice-daily for 8 weeks. Results EGJ-CI was lower in the patients with GERD than that of the controls (P < 0.05). For patients with GERD, EGJ-CI was lower in those with hiatal hernia (P < 0.05). The new metric correlated with esophageal acid exposure in the supine position (P < 0.05), and it also negatively correlated to the total reflux episodes (P < 0.05). There was no significant difference on EGJ-CI between patients with and without response to the esomeprazole treatment (P = 0.627). Conclusions EGJ-CI reflected the dysfunction of the anti-reflux barrier in patients with GERD, but it had little impact on the esomeprazole response. (J Neurogastroenterol Motil 2017;23:27-33)

Esophageal Baseline Impedance Reflects Mucosal Integrity and Predicts Symptomatic Outcome With Proton Pump Inhibitor Treatment

( Chenxi Xie ),( Daniel Sifrim ),( Yuwen Li ),( Minhu Chen ),( Yinglian Xiao ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.1

Background/Aims Esophageal baseline impedance, which is decreased in gastroesophageal reflux disease (GERD) patients, is related to the severity of acid reflux and the integrity of the esophageal mucosa. The study aims to compare the baseline impedance and the dilated intercellular spaces (DIS) within patients with typical reflux symptoms and to evaluate the correlation of baseline impedance with DIS, esophageal acid exposure, as well as the efficacy of proton pump inhibitor (PPI) treatment. Methods Ninety-two patients and 10 healthy controls were included in the study. Erosive esophagitis (EE) was defined by esophageal mucosal erosion under upper endoscopy. Patients without mucosa erosion were divided into groups with pathologic acid reflux (non-erosive reflux disease [NERD]) or with hypersensitive esophagus. The biopsies of esophageal mucosa were taken 2-4 cm above the gastroesophageal junction Z-line during upper endoscopy for DIS measurement. All the patients received esomeprazole 20 mg twice-daily treatment for 8 weeks. The efficacy of esomeprazole was evaluated among all patients. Results The intercellular spaces were dilated in both EE and NERD patients (P < 0.05). The value 0.73 mm could be used as the cut-off DIS value to distinguish patients from controls (area under the curve [AUC] = 0.849, P < 0.01). One thousand seven hundred sixty-four ohms could be used as the cut-off impedance values to distinguish patients from controls (AUC = 0.794, P < 0.01). The baseline impedance was decreased in both EE patients and NERD patients, and negatively correlated to the acid exposure time (r = -0.527, P < 0.05). There was a weak correlation between DIS and baseline impedance (r = -0.230, P < 0.05). “Baseline impedance > 1764 Ω” was an independent predictor for PPI failure (OR, 11.9; 95% CI, 2.4-58.9; P < 0.01). Conclusions The DIS and decreased baseline impedance was observed in patients with mucosa erosion or pathological acid reflux. The baseline impedance reflected the mucosal integrity, it was more sensitive to esophageal acid exposure. Patients with high impedance might not benefit from the PPI treatment. (J Neurogastroenterol Motil 2018;24:43-50)