Screening and Characterization of an Aerobic Nitrifying-denitrifying Bacterium from Activated Sludge

Xiaofan Qiu,Tianwen Wang,Xiaomin Zhong,Guocheng Du,Jian Chen 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.2

Taking advantage of the good biocompatibility and high efficiency of nitrogen removal with microbes,nitrifying and denitrifying bacteria, are becoming increasingly more widely used for wastewater treatment and prevention of eutrophication. In this research, an aerobic nitrifying-denitrifying bacterium was successfully screened from activated sludge and identified as Pseudomonas sp. (CCTCC No M2010209) by the 16S rDNA sequence. The activity verification confirmed its nitrifying-denitrifying capability of removing ammonium, nitrate and nitrite nitrogen. The types of carbon sources and carbon-nitrogen ratio greatly influenced the removal efficiency of NH4+-N and NO3−-N. When the initial concentrations of NH4+-N and NO3−-N in synthetic wastewater were less than 70 and 50mg/L, the nitrogen removal rates reached 94 and 90% in 9 h, respectively. Preliminary comparisons of nitrogen removal capacity between this isolate and other commercial preparations in the treatment of synthetic wastewater revealed its promising potential to be used in the actual wastewater treatment.

Modeling of SACK-based Fast Retransmission and Recovery

Zhiming Wang,Xiaoping Zeng,Xiaofan Jia,Xue Liu,Li Chen 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.6

Selective acknowledgment (SACK)-based retransmission and recovery mechanism has been implemented in most of current transmission control protocol (TCP) stacks. A new SACK-based loss recovery algorithm is defined in RFC6675 under standard track. Existing models in literatures on modeling TCP SACK, which usually use SACK-based retransmission and recovery mechanism, is no longer accurate for two reasons: 1) they ignore transmission of new packets before retransmission of the last loss; 2) they are based on the strategy that pipe is decreased by 2 upon receipt of a partial ACK, where pipe is the estimated number of outstanding packets. This paper develops a new method to derive the expected number of new packets transmitted between retransmission of the first loss and the last, proposes a model that estimates the expected number of packets transmitted during fast retransmission and recovery phase (FRR) and the corresponding expected duration based on RFC6675. The numerical results show that the proposed model can accurately estimate the expected number of packets transmitted during FRR and the corresponding expected duration based on RFC6675.

Risk of Dementia in Long-Term Benzodiazepine Users: Evidence from a Meta-Analysis of Observational Studies

Qian He,Xiaohua Chen,Tang Wu,Liyuan Li,Xiaofan Fei 대한신경과학회 2019 Journal of Clinical Neurology Vol.15 No.1

Background and Purpose There is conflicting evidence in the literature on the association between benzodiazepines (BDZs) and the risk of dementia. This meta-analysis aimed to determine the relationship between the long-term usage of BDZs and the risk of dementia. Methods The PubMed and Embase databases were systematically searched for relevant publications up to September 2017. The literature search focused on observational studies that analyzed the relationship between the long-term use of BDZs and the risk of dementia. Pooled rate ratios (RRs) with 95% confidence interval (CI) were assessed using a random-effects model. The robustness of the results was checked by performing subgroup and sensitivity analyses. Results Ten studies were included: six case–control and four cohort studies. The pooled RR for developing dementia was 1.51 (95% CI=1.17–1.95, p=0.002) in patients taking BDZ. The risk of dementia was higher in patients taking BDZs with a longer half-life (RR=1.16, 95% CI= 0.95–1.41, p=0.150) and for a longer time (RR=1.21, 95% CI=1.04–1.40, p=0.016). Conclusions This meta-analysis that pooled ten studies has shown that BDZ significantly increases the risk of dementia in the elderly population. The risk is higher in patients taking BDZ with a longer half-life (>20 hours) and for a longer duration (>3 years).

Hybridizing gaining–sharing knowledge and differential evolution for large-scale power system economic dispatch problems

Liu Qinghua,Xiong Guojiang,Fu Xiaofan,Mohamed Ali Wagdy,Zhang Jing,Al-Betar Mohammed Azmi,Chen Hao,Chen Jun,Xu Sheng 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.2

Economic dispatch (ED) of thermal power units is significant for optimal generation operation efficiency of power systems. It is a typical nonconvex and nonlinear optimization problem with many local extrema when considering the valve-point effects, especially for large-scale systems. Considering that differential evolution (DE) is efficient in locating global optimal region, while gain-sharing knowledge-based algorithm (GSK) is effective in refining local solutions, this study presents a new hybrid method, namely GSK-DE, to integrate the advantages of both algorithms for solving large-scale ED problems. We design a dual-population evolution framework in which the population is randomly divided into two equal subpopulations in each iteration. One subpopulation performs GSK, while the other executes DE. Then, the updated individuals of these two subpopulations are combined to generate a new population. In such a manner, the exploration and the exploitation are harmonized well to improve the searching efficiency. The proposed GSK-DE is applied to six ED cases, including 15, 38, 40, 110, 120, and 330 units. Simulation results demonstrate that GSK-DE gives full play to the superiorities of GSK and DE effectively. It possesses a quicker global convergence rate to obtain higher quality dispatch schemes with greater robustness. Moreover, the effect of population size is also examined.

Improved Sufficient LMI Conditions for the Robust Stability of Timedelayed Neutral-type Lur’e Systems

Wen-Yong Duan,Baozhu Du,Yan Li,Cuifeng Shen,Xuelai Zhu,Xiaofan Li,Jian Chen 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.5

In this paper, we focus on the problem of the absolute and robustly absolute stability for the neutraltype Lur’e system with time-varying delay. By combining the piecewise analysis theory with extended doubleintegral and Wirtinger-based inequalities technology, some new delay-dependent stability criteria for the absolute and robustly absolute stability are proposed via Lyapunov-Krasovskii functional (LKF) approach. The stability conditions can be expressed as convex linear matrix inequality (LMI) framework, which can be solved by using standard LMI convex optimization solvers. The criteria proposed in this paper are less conservative than some previous ones. Finally, some numerical examples are presented to show the effectiveness of the proposed approach.

Tissue Inhibitor of Metalloproteinase-1 Pro-motes NIH3T3 Fibroblast Proliferation by Activating p-Akt and Cell Cycle Progression

Yang Lu,Shuxin Liu,Shujia Zhang,Guangyan Cai,Hongwei Jiang,Huabin Su,Xiaofan Li,Quan Hong,Xueguang Zhang,Xiangmei Chen 한국분자세포생물학회 2011 Molecules and cells Vol.31 No.3

Tissue inhibitor of metalloproteinase-1 (TIMP-1) plays various roles in cell growth in different cell types. However, few studies have focused on TIMP-1’s effect on fibroblast cells. In this study, we investigated the effects of TIMP-1 overexpression on NIH3T3 fibroblast proliferation and potential transduction signaling pathways involved. Overexpression of TIMP-1, by transfection of the pLenti6/ V5-DESTTIMP-1 plasmid, significantly promoted NIH3T3 proliferation as determined by the BrdU array. Neither 5 nor 15 nM GM6001 (matrix metalloproteinase system inhibitor) affected NIH3T3 proliferation, but 45 nM GM6001 inhibited proliferation. TIMP-1 overexpression activated the p-Akt pathway, but not the p-ERK or p-p38 pathway. In TIMP-1-transfected cells, cyclinD1 was upregulated and p21CIP1 and p27^(KIP1) were downregulated, which promoted cell entry into the S and G2/M phases. The PI3-K inhibitor LY294002 abolished the TIMP-1-induced effects. Overexpression of intracellular TIMP-1 stimulated NIH3T3 fibroblast proliferation in a matrix metalloproteinase (MMP)-independent manner by activating the p-Akt pathway and related cell cycle progression.

Toward better translation of clinical research evidence into rapid recommendations for traditional Chinese medicine interventions: A methodological framework

Sun Xin,Luo Xiaochao,Li Ling,Ma Bin,Yao Minghong,Liu Jiali,Ge Long,Chen Xiaofan,Wu Xi,Deng Hongyong,Zhou Xu,Wen Zehuai,Li Guowei,Li Qianrui 한국한의학연구원 2022 Integrative Medicine Research Vol.11 No.3

Rapid recommendation is a novel methodological framework for developing clinical practice guidelines and this framework shares the basic features of classical guidelines but differs from classical clinical practice guidelines in its ‘rapid’ development process (typically within 90 days) with an aim of translat-ing practice-changing studies to recommendations. A recent global innovation of guideline development methodology is the proposal of a rapid recommendation framework for Traditional Chinese Medicine (TCM), which has the potential to add value to the translation of evidence to practice for TCM inter- ventions. Up to now, more than 180 rapid recommendations have been published, but none of them is pertaining to TCM interventions. Due to the nature of multi-dimensional evidence sources for TCM inter- ventions, including classical randomized controlled trials and real world evidence, a more sophisticated methodological approach to synthesize and evaluate the totality of evidence about effects of TCM in- terventions is required. Therefore, appropriate modification to the rapid recommendation framework is necessary. In the efforts to respond to these needs, we have proposed a specific approach to developing rapid recommendations for TCM interventions the Multi-dimensional Evidence Synthesis, Evaluation and Recommendations for TCM interventions (MESERT)