Purification and Characterization of β-Agarase from Paenibacillus sp.

Jianfeng Mei,Zhongxiu Tang,Yu Yi,Hong Wang,Qi Wang,Guoqing Ying 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.5

β-Agarase produced by Paenibacillus sp. WL(agarase WL) was purified using a combination of ammoniumsulfate precipitation, DEAE-ion exchange, and gel-filtrationchromatography. The purity of the agarase was increasedby 11.9× with a recovery of 5.1% and a specific activity of4,670.1 U/mg of protein. The molecular mass of thepurified agarase was approximately 30 kDa (SDS-PAGE). The agarase was stable at temperature below 50oC and thefavorable agar-hydrolysis activity was at 40oC. The agarasewas active in the range of pH 5.0 to 8.0, and the optimalagar-hydrolysis pH value was approximately 6.0. Metalions normally found in seawater (Na+, K+, Ca2+, Mg2+, andAl3+) could activate agarase WL. The Michaelis-Mentenconstant Km and maximal reaction velocity Vmax of purifiedagarase WL were 3.22 mg/mL and 41.5 μg/mL·min,respectively. The agarase WL was highly agar specific.

Selection of Reference Genes for Gene Expression Studies in Porcine Whole Blood and Peripheral Blood Mononuclear Cells under Polyinosinic:Polycytidylic Acid Stimulation

Wang, Jiying,Wang, Yanping,Wang, Huaizhong,Hao, Xiaojing,Wu, Ying,Guo, Jianfeng Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.4

Investigating gene expression of immune cells of whole blood or peripheral blood mononuclear cells (PBMC) under polyinosinic:polycytidylic acid (poly I:C) stimulation is valuable for understanding the immune response of organism to RNA viruses. Quantitative real-time PCR (qRT-PCR) is a standard method for quantification of gene expression studies. However, the reliability of qRT-PCR data critically depends on proper selection of reference genes. In the study, using two different analysis programs, geNorm and NormFinder, we systematically evaluated the gene expression stability of six candidate reference genes (GAPDH, ACTB, B2M, RPL4, TBP, and PPIA) in samples of whole blood and PBMC with or without poly I:C stimulation. Generally, the six candidate genes performed a similar trend of expression stability in the samples of whole blood and PBMC, but more stably expressed in whole blood than in PBMC. geNorm ranked B2M and PPIA as the best combination for gene expression normalization, while according to NormFinder, TBP was ranked as the most stable reference gene, followed by B2M and PPIA. Comprehensively considering the results from the two programs, we recommended using the geometric mean of the three genes, TBP, PPIA and B2M, to normalize the gene expression of whole blood and PBMC with poly I:C stimulation. Our study is the first detailed survey of the gene expression stability in whole blood and PBMC with or without poly I:C stimulation and should be helpful for investigating the molecular mechanism involved in porcine whole blood and PBMC in response to poly I:C stimulation.

Fast-convergence trilinear decomposition algorithm for angle and range estimation in FDA-MIMO radar

Wang, Cheng,Zheng, Wang,Li, Jianfeng,Gong, Pan,Li, Zheng Electronics and Telecommunications Research Instit 2021 ETRI Journal Vol.43 No.1

A frequency diverse array (FDA) multiple-input multiple-output (MIMO) radar employs a small frequency increment across transmit elements to produce an angle-range-dependent beampattern for target angle and range detection. The joint angle and range estimation problem is a trilinear model. The traditional trilinear alternating least square (TALS) algorithm involves high computational load due to excessive iterations. We propose a fast-convergence trilinear decomposition (FC-TD) algorithm to jointly estimate FDA-MIMO radar target angle and range. We first use a propagator method to obtain coarse angle and range estimates in the data domain. Next, the coarse estimates are used as initialized parameters instead of the traditional TALS algorithm random initialization to reduce iterations and accelerate convergence. Finally, fine angle and range estimates are derived and automatically paired. Compared to the traditional TALS algorithm, the proposed FC-TD algorithm has lower computational complexity with no estimation performance degradation. Moreover, Cramer-Rao bounds are presented and simulation results are provided to validate the proposed FC-TD algorithm effectiveness.

Computer Simulation on Fuzzy Control of Semi-active Suspension System Based on the Whole Vehicle

Jianfeng Wang,Chuanxue Song 보안공학연구지원센터 2013 International Journal of Multimedia and Ubiquitous Vol.8 No.6

Acoustic emission characterization and cracking characteristics of reinforced concrete pipe

Jianfeng Li,Linbing Wang,Dongcan Chen,Yalin Liu,Zhifei Gao,Wentao Wang,Hailu Yang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9

Acoustic emission (AE) and digital image correlation (DIC) technology were used in this study to monitor the behavior of reinforced concrete pipe (RCP) in the optimized three-edge bearing test (TEBT). At the same time, the AE source location of different pipe sections was simulated. The results show that the whole compressive loading process for RCP could be divided into 3 to 4 stages. Both the AE counts and AE energy could well characterize the cracking of concrete, and AE energy was more sensitive to the breaking of steel bar. The amplitude and duration of AE signal produced by the breaking of steel bar were larger than those produced by the cracking of concrete. The AE frequency for concrete cracking was relatively scattered. The AE frequency for steel bar breaking was small and concentrated, and this frequency distribution showed an exponential decreasing trend. The results of optimized AE source location showed that the generation and development of cracks occur in the initial loading stage. The results of multi-index analysis showed that the cracks in the top (loading position) and the bottom (bearing position) of the RCP show that the cracks extend from the inner wall to the outer wall, while the cracks on the left and right sides perpendicular to the loading direction show that the cracks extend from the outer wall to the inner wall.

Effect of Sheep and Chicken Antibodies to Rat Adipocytes Plasma Membranes on Rat Carcass Fat

Wang, Jundong,Zhang, Jianfeng,Li, Junping,Hao, Junhu,Wang, Shaolin,Zhang, Jianhai Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.8

Polyclonal anti-sera were collected from sheep and chicken immunized with adipocytes plasma membranes. Thirty two male wistar rats, weighing 185-215 grams, were divided randomly into 4 groups (trial 1: control group and treat group, trial 2: control group and treat group), with 8 rats in each group. The experiment lasted for 7 weeks. Trial one: The control group received four consecutive daily intraperitoneal injections of 1ml of sheep normal sera. The same 4 day daily dose of group sheep anti-rats sera adipocyte plasma membrane anti-sera was administered to the treat group. The results showed that the treatment for treat group increased body weight by 6.35% (p<0.05) and food intake by 6.85%, and improved food conversion efficiency (Food intake/gain) by 45.00% (p<0.05). Periernal, epididymal and omental adipose deposit weights were decreased by 23.92% (p<0.05), 34.45% (p<0.05) and 0.98% respectively, while total fat content decreased by 20.92%. Trial two: The control group received four consecutive daily intraperitoneal injections of 1 ml of chicken normal sera, the results of injections of chicken anti-rats sera adipocyte plasma membrane antis-era administered to the treat group indicated that chicken anti-rats adipocyte plasma membranes immunization had an disadvantageous effect on the growth of the wistar rats by the end of 7th wk, compared with the control group. The immunized group decreased in total weight by 40 gram (p<0.05) an averagely and in food intake noticeably (p<0.01). The deposition of fat and the rates of TG and FFA in serum had no statistical significance.

Phase lag compensation for improving the stability of LCL‑type converters under weak grid condition

Jianfeng Wang,Guobing Pan,Jing Ouyang,Chengyao Liu,Yinghao Zhou,Gong Fei 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.5

LCL-type converters are widely used in the sustainable energy generation system due to their flexible current control strategies and high efficiency. The LCL filter has a resonance peak, which needs to be handled appropriately; otherwise, it causes system instability. Single-loop feedback control strategy is very popular at present; it does not require additional sensors to measure the state variables for active damping. Under weak grid condition, the resonance peak of LCL filter shifts to the left evidently and greatly reduces the stability margin; thus, maintaining the stability of single-loop control is a challenging task. This paper presents an improved grid current feedback (GCF) single-loop control strategy, which is designed to raise the stability margin of system to adapt weak grid condition. Low pass filter controller is used for phase lag compensation. A phase margin design method is proposed to ensure system stability, and the corresponding discrete method in z-domain has been proposed in detail. Experiments performed on a three-phase converter platform are finally presented to verify the effectiveness of the proposed phase lag compensation for GCF control strategy.

Microstructure, Thermal Behavior and Tensile Properties of Laser Welded Bottom-Locking Joint for TA15 Titanium Alloy

Jiayao Wang,Jianfeng Wang,Yanqiu Zhao,Yue Li,Xiaohong Zhan 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.5

The present investigation aims at the thermal conditions for the TA15 titanium alloy laser welded bottom-locking joint. Bottom-locking featured specimens under three welding speeds were manufactured to study the grain morphology and tensileproperties. Finite element computation based on temperature field simulation was conducted in order to shed more light on themicrostructure characteristics of the bottom-locking joint. The results indicate a significant influence of the welding speed onthe thermal cycle, microstructure evolution and tensile performance. As the welding speed increases, the width of weld zone(WZ) is decreased significantly. At the same time, the columnar crystal features a coarser shape and its growth cross regionat the bottom of WZ becomes smaller with the increasing welding speed. Besides, the size of martensite decreases with theincreasing of welding speed. With the support of both numerical and experimental results, complex microstructure evolutionmechanisms were revealed involving thermal cycle related to the welding speed. In addition, the laser welded bottom-lockingjoint of TA15 titanium alloy is even fractured at the base metal, which exhibits the comparable tensile properties. The EDSresults illustrate the inevitable burning losses of stabilization element during the welding process. All these mechanisms areassociated with the bottom-locking joint arrangement and the welding speed-induced thermal cycle.

Cardiac-targeted delivery of nuclear receptor RORα via ultrasound targeted microbubble destruction optimizes the benefits of regular dose of melatonin on sepsis-induced cardiomyopathy

Shanjie Wang,Kegong Chen,Ye Wang,Zeng Wang,Zhaoying Li,JunChen Guo,Jianfeng Chen,Wenhua Liu,Xiaohui Guo,Guangcan Yan,Chenchen Liang,Huai Yu,Shaohong Fang,Bo Yu 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Large-dose melatonin treatment in animal experiments was hardly translated into humans, which may explain the dilemma that the protective effects against myocardial injury in animal have been challenged by clinical trials. Ultrasound-targeted microbubble destruction (UTMD) has been considered a promising drug and gene delivery system to the target tissue. We aim to investigate whether cardiac gene delivery of melatonin receptor mediated by UTMD technology optimizes the efficacy of clinically equivalent dose of melatonin in sepsis-induced cardiomyopathy. Methods Melatonin and cardiac melatonin receptors in patients and rat models with lipopolysaccharide (LPS)- or cecal ligation and puncture (CLP)-induced sepsis were assessed. Rats received UTMD-mediated cardiac delivery of RORα/cationic microbubbles (CMBs) at 1, 3 and 5 days before CLP surgery. Echocardiography, histopathology and oxylipin metabolomics were assessed at 16–20 h after inducing fatal sepsis. Results We observed that patients with sepsis have lower serum melatonin than healthy controls, which was observed in the blood and hearts of Sprague–Dawley rat models with LPS- or CLP-induced sepsis. Notably, a mild dose (2.5 mg/kg) of intravenous melatonin did not substantially improve septic cardiomyopathy. We found decreased nuclear receptors RORα, not melatonin receptors MT1/2, under lethal sepsis that may weaken the potential benefits of a mild dose of melatonin treatment. In vivo, repeated UTMD-mediated cardiac delivery of RORα/CMBs exhibited favorable biosafety, efficiency and specificity, significantly strengthening the effects of a safe dose of melatonin on heart dysfunction and myocardial injury in septic rats. The cardiac delivery of RORα by UTMD technology and melatonin treatment improved mitochondrial dysfunction and oxylipin profiles, although there was no significant influence on systemic inflammation. Conclusions These findings provide new insights to explain the suboptimal effect of melatonin use in clinic and potential solutions to overcome the challenges. UTMD technology may be a promisingly interdisciplinary pattern against sepsis-induced cardiomyopathy.

Genome-wide association study for intramuscular fat content in Chinese Lulai black pigs

Yanping Wang,Chao Ning,Cheng Wang,Jianfeng Guo,Jiying Wang,Ying Wu 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.5

Objective: Intramuscular fat (IMF) content plays an important role in meat quality. Identification of single nucleotide polymorphisms (SNPs) and genes related to pig IMF, especially using pig populations with high IMF content variation, can help to establish novel molecular breeding tools for optimizing IMF in pork and unveil the mechanisms that underlie fat metabolism. Methods: We collected muscle samples of 453 Chinese Lulai black pigs, measured IMF content by Soxhlet petroleum-ether extraction method, and genotyped genome-wide SNPs using GeneSeek Genomic Profiler Porcine HD BeadChip. Then a genome-wide association study was performed using a linear mixed model implemented in the GEMMA software. Results: A total of 43 SNPs were identified to be significantly associated with IMF content by the cutoff p<0.001. Among these significant SNPs, the greatest number of SNPs (n = 19) were detected on Chr.9, and two linkage disequilibrium blocks were formed among them. Additionally, 17 significant SNPs are mapped to previously reported quantitative trait loci (QTLs) of IMF and confirmed previous QTLs studies. Forty-two annotated genes centering these significant SNPs were obtained from Ensembl database. Overrepresentation test of pathways and gene ontology (GO) terms revealed some enriched reactome pathways and GO terms, which mainly involved regulation of basic material transport, energy metabolic process and signaling pathway. Conclusion: These findings improve our understanding of the genetic architecture of IMF content in pork and facilitate the follow-up study of fine-mapping genes that influence fat deposition in muscle.