Kinetics Study of Enzymatic Hydrolysis of Paulownia by Dilute Acid, Alkali, and Ultrasonic-assisted Alkali Pretreatments

Xiao-kun Ye,Yuancai Chen 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.2

Paulownia, a fast-growing and high-fiber plant (cellulose: 41.66% and hemicellulose: 19.61%), has the potential to serve as an interesting source for production of bioethanol. The aim of this paper is to study and compare the kinetics of enzymatic hydrolysis of Paulownia pretreated by dilute acid (DA), alkali (AL) and ultrasonic-assisted alkali (UA). The enzymatic hydrolysis was performed at 50°C, atmospheric pressure with 40 FPU/g-cellulose cellulase and 80 CBU/g-cellulose cellobiase. The hydrolysis process can be successfully described by the Michaelis-Menten model under the three pretreatment conditions. Due to the high removal of lignin and increased porosity of the substrate, UA pretreatment is proved to be the most effective method in improving enzymatic saccharification, followed by DA pretreatment and alkali (AL) pretreatment. Inhibition constant KI of all experiments (DA: 2.16 g/L, AL: 3.12 g/L and UA: 1.83 g/L) suggests that glucose has a strong inhibition for enzymatic hydrolysis, for lower KI is proportional to higher inhibition performance. The experimental date fits well with kinetics model. This indicates that the model is suitable for performance monitoring, conditions optimization and process control at full-scale studies.

Meta-analysis of Seven Randomized Control Trials to Assess the Efficacy and Toxicity of Combining EGFR-TKI with Chemotherapy for Patients with Advanced NSCLC who Failed First-Line Treatment

Xiao, Bing-Kun,Yang, Jian-Yun,Dong, Jun-Xing,Ji, Zhao-Shuai,Si, Hai-Yan,Wang, Wei-Lan,Huang, Rong-Qing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Background: Some recent clinical trials have been conducted to evaluate a combination of EGFR- TKI with chemotherapy for advanced NSCLC patients as second-line therapy, but the results on the efficacy of such trials are inconsistent. The aim of this meta-analysis was to evaluate the efficacy and safety of combination of EGFR-TKI and chemotherapy for patients with advanced NSCLC who failed first-line treatment. Materials and Methods: We searched relative trials from PubMed, EMBASE, ASCO Abstracts, ESMO Abstracts, Cochrane Library and Clinical Trials.gov. Outcomes analyzed were overall response rate (ORR), progression- free survival (PFS), overall survival (OS) and major toxicity. Results: Seven trails eventually were included in this meta-analysis, covering 1,168 patients. The results showed that the combined regimen arm had a significant higher ORR (RR 1.76 [1.16, 2.66], p=0.007) and longer PFS (HR 0.75 [0.66-0.85], p<0.00001), but failed to show effects on OS (HR 0.88 [0.68-1.15], p=0.36). In terms of subgroup results, continuation of EGFR-TKI in addition to chemotherapy after first-line EGFR-TKI resistance confered no improvement in ORR (RR 0.95 [0.68, 1.33], p=0.75) and PFS (HR 0.89[0.69, 1.15], p=0.38), and OS was even shorter (HR1.52 [1.05-2.21], p=0.03). However, combination therapy with EGFR-TKI and chemotherapy after failure of first-line chemotherapy significantly improved the ORR (RR 2.06 [1.42, 2.99], p=0.0002), PFS (HR 0.71 [0.61, 0.82], p<0.00001) and OS (HR 0.74 [0.62-0.88], p=0.0008), clinical benefit being restricted to combining EGFR-TKI with pemetrexed, but not docetaxel. Grade 3-4 toxicity was found at significantly higher incidence in the combined regimen arm. Conclusions: Continuation of EGFR-TKI in addition to chemotherapy after first-line EGFR-TKI resistance should be avoided. Combination therapy of EGFR-TKI and pemetrexed for advanced NSCLC should be further investigated for prognostic and predictive factors to find the group with the highest benefit of the combination strategy.

A Novel Energy Entropy Based on Clusterhead Selection Algorithm for Wireless Sensor Networks

Kun Xiao,Baolin Sun,Chao Gui,Hua Chen 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.3

Energy is the primary constraint on designing wireless sensor networks (WSNs) practically, leading to limited network lifetime of WSN. Different communication protocols and algorithms are investigated to find ways to reduce power consumption. Cluster formation and clusterhead selection are critical issues in WSN, which can prolong the lifetime and also improve the network’s performance. In order to maintain the stability of clusters, energy of wireless sensor nodes and connectivity are taken as the basis of clusterhead election. We consider the problem of appropriate clusterhead selection in WSNs. This paper proposes a Novel Energy Entropy Based on Clusterhead Selection Algorithm for WSNs (EE-CSAW). The protocol constructs a new metric of node stability and selects a stable clusterhead with the help of entropy metric to reduce the number of clusterhead reconstruction. It selects the nodes which have the most weight and stability to be the clusterheaders. Simulations demonstrate the performance benefits of our proposal EE-CSAW over SLEACH and Thein’s proposed algorithm in WSNs.

Electrical Conductivity Enhancement of Epoxy by Hybrid Carbon Nanotubes and Self-made Silver Nanoparticles

Xiao Min Zhang,Xiao-Li Yang,Kun-yan Wang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.7

Flexibility electrode with high stretchability, electrical conductivity, and good mechanical properties are desirable,owing to their promising applications in electronic circuit and human motion monitoring systems. In this paper, a highperformance flexibility electrode was prepared based on printable and electrically conductive adhesive (ECA). Thisflexibility electrode is fabricated by mixing silver nanoparticles (AgNPs), carbon nanotube (CNT) and epoxy resin andscreen-printed to a required shape. The spherical AgNPs were prepared by DC arc plasma method. The Ag NPs present apolycrystalline crystal structure, the particle’s diameter range from 20 to 150 nm, with an average of 80 nm. Simultaneously,this flexibility electrode provides the advantages of simple, scalable fabrication, robust mechanical properties and versatilityin applications. Based on these performance characteristics, its applications in flexible printed electrodes are demonstrated,revealing its tremendous potential for applications in flexible and wearable electronics. The flexibility sensor prepared byECA exhibits fascinating comprehensive performances. The ECA filled with 65 % Ag NPs and 0.8 % CNT shows anexcellent electrical conductivity (9×10-4 Ω·cm) and bonding strength (9.2 MPa).

RASSF1A Gene Methylation is Associated with Nasopharyngeal Carcinoma Risk in Chinese

Wu, Kun,Xu, Xiao-Ning,Chen, Yu,Pu, Xiao-Lin,Wang, Bo-Yuan,Tang, Xiao-Dan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

In order to explore the association between RASSF1A methylation and nasopharyngeal carcinoma (NPC) risk of Chinese, we carried out a meta-analysis with searches of PubMed, Web of Science, ProQest and Medline databases. Ultimately, 14 articles were identified and analysised using R Software (R version 3.1.2) including meta packages. Overall, we found a significant relationship between RASSF1A methylation and NPC risk (OR 30.7; 95 % CI, 16.71~56.23; z=11.0591; p<0.0001) in a fixed effects model and (OR 32.1; 95% CI, 14.27~72.01; z=8.3984; p<0.0001) in a random effects model pooled. In tissue and NP brushings groups, similar results were found. Hence, our study identified a strong association between RASSF1A methylation and NPC and highlighted a promising potential for RASSF1A methylation in NPC risk prediction of Chinese.

Process of Equiaxed Grains of RE-Al Alloy under Slope Vibration

Xie Shi-kun,Yi Rong-xi,Pan Xiao-liang,Zheng Xiao-qiu,Guo Xiu-yan 한국소성가공학회 2010 기타자료 Vol.2010 No.6

A new technique using slope vibration casting process during heating and isothermal holding period to prepare Al-7Si-2RE alloy has been studied. The small, near-spherical and non-dendritic microstructure with the semi-solid processing requirements has been obtained. Experiments show that the cooling method, pouring process and the convection of melt caused by slope vibration had significant effects on the formation of near-spherical primary gains. The water-cooled copper mold casting with slope vibration at the temperature near liquidus can obtain Al-7Si-2RE alloy with small homogeneous equiaxed grains, the average grain diameter is 48.3μm, and the average grain roundness is 1.92.

Distinct Transcriptional and Functional Differences of Lung Resident and Monocyte-Derived Alveolar Macrophages During the Recovery Period of Acute Lung Injury

Hou Fei,Wang Huan,Zheng Kun,Yang Wenting,Xiao Kun,Rong Zihan,Xiao Junjie,Li Jing,Cheng Baihe,Tang Li,Xie Lixin 대한면역학회 2023 Immune Network Vol.23 No.3

In acute lung injury, two subsets of lung macrophages exist in the alveoli: tissue-resident alveolar macrophages (AMs) and monocyte-derived alveolar macrophages (MDMs). However, it is unclear whether these 2 subsets of macrophages have different functions and characteristics during the recovery phase. RNA-sequencing of AMs and MDMs from the recovery period of LPS-induced lung injury mice revealed their differences in proliferation, cell death, phagocytosis, inflammation and tissue repair. Using flow cytometry, we found that AMs showed a higher ability to proliferate, whereas MDMs expressed a larger amount of cell death. We also compared the ability of phagocytosing apoptotic cells and activating adaptive immunity and found that AMs have a stronger ability to phagocytose, while MDMs are the cells that activate lymphocytes during the resolving phase. By testing surface markers, we found that MDMs were more prone to the M1 phenotype, but expressed a higher level of pro-repairing genes. Finally, analysis of a publicly available set of single-cell RNA-sequencing data on bronchoalveolar lavage cells from patients with SARS-CoV-2 infection validated the double-sided role of MDMs. Blockade of inflammatory MDM recruitment using CCR2−/− mice effectively attenuates lung injury. Therefore, AMs and MDMs exhibited large differences during recovery. AMs are long-lived M2-like tissue-resident macrophages that have a strong ability to proliferate and phagocytose. MDMs are a paradoxical group of macrophages that promote the repair of tissue damage despite being strongly pro-inflammatory early in infection, and they may undergo cell death as inflammation fades. Preventing the massive recruitment of inflammatory MDMs or promoting their transition to pro-repairing phenotype may be a new direction for the treatment of acute lung injury.

Three-dimensional Network Structure of Conductive Composites by Hybrid Conductive Fillers of Silver/graphene

Xiao Min Zhang,Kun-yan Wang,Guo Zhao,Qi Long Li,Bin Wang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

In order to explore new generations of interconnecting materials in electronic packaging industries, silvernanoparticles (Ag NPS) and graphene nanosheets (GNS) were introduced into matrix resin to prepare conductive composites. The electrical and mechanical of above electrically conductive adhesives (ECAs) were investigated and characterized. It wasfound that the ECAs can be solidified through a chemical sintering in the air at 150 oC for 30 min. The results indicated thatthe percolation threshold of resistivity reaches 3.5×10-4 Ω·cm for ECAs filled with 65 wt.% Ag NPS, 0.5 wt.% GNS and theshear strength reaches 10.8 MPa, suggesting excellent electric conductivity and bonding strength.

Production of vinegar using edible alcohol as feedstock through high efficient biotransformation by acetic acid bacteria

Xiao-Yan Yin,Xu Chang,Wu-Kun Zhong,Jiao Huo,Zhong-Hua Yang 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.2

In this paper, an optimal semi-continuous process for vinegar production from edible alcohol through biotransformation by acetic acid bacteria (AAB) WUST-01 was developed. The optimized medium composition for the starting-up stage was glucose 5.1 g/L, yeast extract 26.2 g/L, and ethanol 11.9 mL/L, and the optimal ethanol for the following semi-continuous stage was 50 mL/L. In the semi-continuous biotransformation process, the optimal withdraw ratio was 50% of working volume with 12 h cycle time. With these conditions, the total acidity could reach to 77.3 g/L and the acidity productivity could reach to 3.0 g/(L h) in a 5 L reactor. Furthermore, it was investigated to strengthen vinegar synthesis through enhancing alcohol dehydrogenase and aldehyde dehydrogenase activity in AAB by ferrous ion and pueraria flower extract as the enzyme regulators. With these regulators, the vinegar synthesis efficiency can be improved 16.3 and 13.2% respectively.

Current Status of Indoor Positioning System Based on Visible Light

Kun Yan,Haiyan Zhou,Hailin Xiao,Xiangli Zhang 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

With the flourishing of wireless information access, indoor positioning is becoming a topic of interest in both academic and industry community. Numerous techniques have been proposed to address this problem under diverse circumstances. Recently, the area of indoor positioning is dominated by three kinds of methodologies, such as rangebased positioning, fingerprint-based positioning and inertial positioning. This paper is presented to overview the indoor positioning techniques using visible light based on the range-based positioning. The state-of-the-art research results will be studied. The typical localization mechanisms used in visible light positioning systems are analyzed by evaluation metrics to provide an insight of the systems’ performances.