Numerical simulation and experiments of magnetic flux leakage inspection in pipeline steel

Xun-Bo Li,Xiang Li,Liang Chen,Pei-Fu Feng,Hai-Dong Wang,Zuo-Ying Huang 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.1

The magnetic flux leakage (MFL) method is currently the most commonly used pipeline inspection technique. In this paper, numerical simulation and experimental investigation on defect inspection in pipeline steel using MFL were carried out. In theoretical analysis, typical three-dimensional (3D) defects were accurately modeled and detailed MFL signals in the test surface were calculated by 3D finite element method (FEM). To confirm the 3D FEM results, different artificial defects were made and the MFL experiments were performed. The experimental study demonstrated that the results were agreement with the 3D FEM result. The results show that the 3D FEM is an effective analysis method for pipeline steel MFL inspection.

Molecular and Biochemical Characterization of a Novel Xylanase from Massilia sp. RBM26 Isolated from the Feces of Rhinopithecus bieti

( Bo Xu ),( Li Ming Dai ),( Jun Jun Li ),( Meng Deng ),( Hua Biao Miao ),( Jun Pei Zhou ),( Yue Lin Mu ),( Qian Wu ),( Xiang Hua Tang ),( Yun Juan Yang ),( Jun Mei Ding ),( Nan Yu Han ),( Zun Xi Huang 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37°C and could maintain at least 96% activity after being placed at 37°C for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, Km, Vmax, and kcat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 μmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

Laser Patterning Technology Based on Nanosecond Pulsed Laser for Manufacturing Bifacial Perovskite Solar Modules

Bo-Qian Lin,Chao-Peng Huang,Kuo-Yo Tian,Pei-Huan Lee,Wei-Fang Su,Li Xu 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.1

Bifacial semi-transparent perovskite (PVSK) solar cell is a promising candidate to achieve high photo-electrical conversion efficiency (PCE) in a tandem structure with Si solar cells. The gap between lab-scale cells and large area modules needs to be closed using innovative patterning technology. In this paper we demonstrate that a single nanosecond pulsed laser (wavelength 532 nm, pulse duration 7 ns) can be used to perform all scribing processes, i.e. P1, P2 and P3, to manufacture PVSK solar modules. Compared to picosecond or femtosecond lasers reported in the literature, our approach has the advantages of high stability and low cost, and is thus applicable to large scale manufacturing of PVSK solar modules. Detailed laser processing parameters such as laser power and overlap ratio etc. have been studied to achieve optimal results for each scribing process. A mini module with two cells was fabricated on a 2 × 2 cm2 substrate, showing an active area efficiency of 12.5%, FF of 72.4%, and high GFF of 94%.

Molecular Biology and Omics : Cloning and Characterization of a Novel α-Amylase from a Fecal Microbial Metagenome

( Bo Xu ),( Fu Ya Yang ),( Cai Yun Xiong ),( Jun Jun Li ),( Xiang Hua Tang ),( Jun Pei Zhou ),( Zhen Rong Xie ),( Jun Mei Ding ),( Yun Juan Yang ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.4

To isolate novel and useful microbial enzymes from uncultured gastrointestinal microorganisms, a fecal microbial metagenomic library of the pygmy loris was constructed. The library was screened for amylolytic activity, and 8 of 50,000 recombinant clones showed amylolytic activity. Subcloning and sequence analysis of a positive clone led to the identification a novel gene (amyPL) coding for α-amylase. AmyPL was expressed in Escherichia coli BL21 (DE3) and the purified AmyPL was enzymatically characterized. This study is the first to report the molecular and biochemical characterization of a novel α-amylase from a gastrointestinal metagenomic library.

An Effective Guidewire Looping Technique for the Recanalization of Occlusive Segments of Infrapopliteal Vessels

Jian-bo Wang,Jun-gong Zhao,Ming-hua Li,Yue-qi Zhu,Jue Wang,Pei-lei Zhang 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.4

Objective: To determine the efficacy, safety and primary follow-up results of a guidewire looping technique for the treatment of infrapopliteal arteries. Materials and Methods: From October 2006 to May 2008, an intraluminal angioplasty of the infrapopliteal arteries was attempted in 200 consecutive patients. Altogether, 417 infrapopliteal lesions, with lengths varying from 2 cm to 32 cm, were treated as part of this study, including 305 lesions in the anterior tibial arteries, 89 in the posterior tibial arteries, and 23 in the peroneal arteries. The ‘U’-shaped guidewire technique was attempted in 393 lesions from 361 limbs. The tip of a hydrophilic 0.035-inch guidewire was formed into a ‘U’ shape with the aid of a 4-Fr catheter and collateral branch vessel to recanalize the completely occluded long segment lesions. Results: A successful angioplasty with at least one artery recanalized directly to the malleolar or dorsal foot was achieved in 322 limbs (89%). The looping technique had a success rate of 90% (352 of 393 lesions). After the procedure, the rest pain was relieved in 58 of 69 patients, while 207 of 245 limbs (85%) showed improvement for intermittent claudication. Complete wound healing was noted in 21 of 54 patients, while 20 of 54 patients showed an improvement in the wound size or depth. A total of 38 major immediate procedure-related complications were noted, including retroperitoneal hematoma, distal emboli, and vessel rupture. Conclusion: The results of this study suggests that the guidewire looping technique is a safe and effective method for the recanalization of the occluded lesions in infrapopliteal vessels. Objective: To determine the efficacy, safety and primary follow-up results of a guidewire looping technique for the treatment of infrapopliteal arteries. Materials and Methods: From October 2006 to May 2008, an intraluminal angioplasty of the infrapopliteal arteries was attempted in 200 consecutive patients. Altogether, 417 infrapopliteal lesions, with lengths varying from 2 cm to 32 cm, were treated as part of this study, including 305 lesions in the anterior tibial arteries, 89 in the posterior tibial arteries, and 23 in the peroneal arteries. The ‘U’-shaped guidewire technique was attempted in 393 lesions from 361 limbs. The tip of a hydrophilic 0.035-inch guidewire was formed into a ‘U’ shape with the aid of a 4-Fr catheter and collateral branch vessel to recanalize the completely occluded long segment lesions. Results: A successful angioplasty with at least one artery recanalized directly to the malleolar or dorsal foot was achieved in 322 limbs (89%). The looping technique had a success rate of 90% (352 of 393 lesions). After the procedure, the rest pain was relieved in 58 of 69 patients, while 207 of 245 limbs (85%) showed improvement for intermittent claudication. Complete wound healing was noted in 21 of 54 patients, while 20 of 54 patients showed an improvement in the wound size or depth. A total of 38 major immediate procedure-related complications were noted, including retroperitoneal hematoma, distal emboli, and vessel rupture. Conclusion: The results of this study suggests that the guidewire looping technique is a safe and effective method for the recanalization of the occluded lesions in infrapopliteal vessels.

Role of Selenium in Alteration of Erythrocyte Parameters in Bovine Fluorosis

Han, Bo,Yoon, Soon-Seek,Wu, Pei-Fu,Han, Hong-Ryul,Liang, Li-Cheng Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.6

Signs of dental discolouration, difficulty in mastication, bony exostosis and debility were observed in cattle from Qingtongxia Ningxia, China where fluoride concentration in drinking water, soil, fodder, serum, bone, teeth, haircoat and urine were significantly higher than the corresponding health site. The problem of fluorosis in beef cattle is attributable to water containing toxic levels of fluoride. The objective of this paper was therefore to evaluate the influence of fluoride on erythrocyte parameters in cattle under high fluoride and low selenium conditions, as well as the protective efficacy of selenium exposure in feedstuff for bovine endemic fluorosis. Sixteen 6 to 7 year-old high fluoride beef cattle were randomly allotted into two groups each with eight cows: high fluoride control group, and supplemented with 0.25 mg/kg selenium per day for 83 days respectively. In addition, eight 6 to 7 year-old normal control beef cattle were selected from a non-high fluoride site. Blood samples were collected on day 0, 30 and 83 for erythrocyte parameters analysis and scanning electronic microscopy. The results indicated that erythrocytes, hemoglobin, packed cell volume values and $Na^+-K^+$ ATPase activity from affected cattle on the high fluoride site were significantly reduced during the period as compared with the corresponding samples of normal control cattle, a great number of echinocytes were present in peripheral blood, and subsequent anaemia. However, affected cattle exposed to selenium revealed increasable erythrocyte parameters, the extent of elevation in these values being dependent on the duration of supplementation with selenium. These findings suggest that fluoride exposure can cause erythrocyte damage, whereas selenium supplementation can antagonize fluoride-induced generation of free radicals and cumulative effects of lipid peroxidation in erythrocytes. Selenium supplementation may help to alleviate the possible hazards associated with bovine endemic fluorosis.

Cloning, Heterologous Expression, and Characterization of Novel Protease- Resistant α-Galactosidase from New Sphingomonas Strain

( Jun Pei Zhou ),( Yan Yan Dong ),( Jun Jun Li ),( Rui Zhang ),( Xianghua Tang ),( Yuelin Mu ),( Bo Xu ),( Qian Wu ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.11

The α-galactosidase-coding gene agaAJB13 was cloned from Sphingomonas sp. JB13 showing 16S rDNA (1,343 bp) identities of ≤97.2% with other identified Sphingomonas strains. agaAJB13 (2,217 bp; 64.9% GC content) encodes a 738-residue polypeptide (AgaAJB13) with a calculated mass of 82.3 kDa. AgaAJB13 showed the highest identity of 61.4% with the putative glycosyl hydrolase family 36 α-galactosidase from Granulicella mallensis MP5ACTX8 (EFI56085). AgaAJB13 also showed <37% identities with reported protease-resistant or Sphingomonas α-galactosidases. A sequence analysis revealed different catalytic motifs between reported Sphingomonas α-galactosidases (KXD and RXXXD) and AgaAJB13 (KWD and SDXXDXXXR). Recombinant AgaAJB13 (rAgaAJB13) was expressed in Escherichia coli BL21 (DE3). The purified rAgaAJB13 was characterized using p-nitrophenyl-α-D-galactopyranoside as the substrate and showed an apparent optimum at pH 5.0 and 60oC and strong resistance to trypsin and proteinase K digestion. Compared with reported proteaseresistant α-galactosidases showing thermolability at 50oC or 60oC and specific activities of <71 U/mg with or without protease treatments, rAgaAJB13 exhibited a better thermal stability (half-life of >60 min at 60oC) and higher specific activities (225.0-256.5 U/mg). These sequence and enzymatic properties suggest AgaAJB13 is the first identified and characterized Sphingomonas α-galactosidase, and shows novel protease resistance with a potential value for basic research and industrial applications.

Molecular and Biochemical Characterization of a Novel Intracellular Low-Temperature-Active Xylanase

( Jun Pei Zhou,),( Yan Yan Dong ),( Xiang Hua Tang ),( Jun Jun Li ),( Bo Xu ),( Qian Wu ),( Ya Jie Gao ),( Lu Pan ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.4

A 990 bp full-length gene (xynAHJ2) encoding a 329- residue polypeptide (XynAHJ2) with a calculated mass of 38.4 kDa was cloned from Bacillus sp. HJ2 harbored in a saline soil. XynAHJ2 showed no signal peptide, distinct amino acid stretches of glycoside hydrolase (GH) family 10 intracellular endoxylanases, and the highest amino acid sequence identity of 65.3% with the identified GH 10 intracellular mesophilic endoxylanase iM-KRICT PX1-Ps from Paenibacillus sp. HPL-001 (ACJ06666). The recombinant enzyme (rXynAHJ2) was expressed in Escherichia coli and displayed the typical characteristics of low-temperatureactive enzyme (exhibiting optimum activity at 35 o C, 62% at 20 o C, and 38% at 10 o C; thermolability at ≥45 o C). Compared with the reported GH 10 low-temperature-active endoxylanases, which are all extracellular, rXynAHJ2 showed low amino acid sequence identities (<45%), low homology (different phylogenetic cluster), and difference of structure (decreased amount of total accessible surface area and exposed nonpolar accessible surface area). Compared with the reported GH 10 intracellular endoxylanases, which are all mesophilic and thermophilic, rXynAHJ2 has decreased numbers of arginine residues and salt bridges, and showed resistance to Ni 2+ , Ca 2+ , or EDTA at 10 mM final concentration. The above mechanism of structural adaptation for low-temperature activity of intracellular endoxylanase rXynAHJ2 is different from that of GH 10 extracellular low-temperature-active endoxylanases. This is the first report of the molecular and biochemical characterizations of a novel intracellular low-temperatureactive xylanase.

Serum Macrophage Migration Inhibitory Factor as a Biomarker of Active Pulmonary Tuberculosis

Zhong-bo Shang,Jun Wang,Shou-gang Kuai,Yin-yin Zhang,Qin-fang Ou,Hao Pei,Li Hua Huang 대한진단검사의학회 2018 Annals of Laboratory Medicine Vol.38 No.1

Background: Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine with chemokine-like functions, has been shown to play a central role in several acute and chronic inflammatory diseases. However, limited information is available regarding the use of MIF as an inflammatory pathway marker in patients with tuberculosis. This study aimed to investigate the association of MIF with IFN-γ and TNF-α in active pulmonary tuberculosis (APTB) following anti-tuberculosis treatment. Methods: The MIF, TNF-α, and IFN-γ serum levels were determined in 47 patients with APTB by cytokine-specific ELISA at four phases: prior to anti-tuberculosis drug treatment (baseline), and following 2, 4, and 6 months of treatment. In addition, we measured the MIF, TNF-α, and IFN-γ serum levels in 50 health controls. Results: MIF serum levels were significantly elevated (P<0.05) in patients with APTB prior to treatment compared with that in control subjects, and TNF-α ≥449.7 pg/mL was associated with high MIF levels (≥13.1 ng/mL). MIF levels were significantly reduced (P<0.01) following 2, 4, and 6 months of treatment, with variations in TNF-α and IFN-γ serum levels. MIF levels were positively correlated with the paired TNF-α level at baseline (r=0.1103, P=0.0316) and following 6 months of treatment (r=0.09569, P=0.0364).Conclusions: A reduction in the MIF serum levels in patients with APTB following anti-tuberculosis treatment may positively affect host immune protection against Mycobacterium tuberculosis infection. Thus, serum MIF levels may constitute a useful marker for assessing therapy effectiveness in patients with APTB.

Association between Intracranial Arterial Dolichoectasia and Cerebral Small Vessel Disease and Its Underlying Mechanisms

Dao Pei Zhang,Suo Yin,Huai Liang Zhang,Dan Li,Bo Song,Jia Xu Liang 대한뇌졸중학회 2020 Journal of stroke Vol.22 No.2

Intracranial arterial dolichoectasia (IADE), also known as dilatative arteriopathy of the brain vessels, refers to an increase in the length and diameter of at least one intracranial artery, and accounts for approximately 12% of all patients with stroke. However, the association of IADE with stroke is usually unclear. Cerebral small vessel disease (CSVD) is characterized by pathological changes in the small vessels. Clinically, patients with CSVD can be asymptomatic or present with stroke or cognitive decline. In the past 20 years, a series of studies have strongly promoted an understanding of the association between IADE and CSVD from clinical and pathological perspectives. It has been proposed that IADE and CSVD may be attributed to abnormal vascular remodeling driven by an abnormal matrix metalloproteinase/tissue inhibitor of metalloproteinase pathway. Also, IADErelated hemodynamic changes may result in initiation or progression of CSVD. Additionally, genetic factors are implicated in the pathogenesis of IADE and CSVD. Patients with Fabry’s disease and late-onset Pompe’s disease are prone to developing concomitant IADE and CSVD, and patients with collagen IV alpha 1 or 2 gene (COL4A1/COL4A2) and forkhead box C1 (FOXC1) variants present with IADE and CSVD. Race, strain, familial status, and vascular risk factors may be involved in the pathogenesis of IADE and CSVD. As well, experiments in mice have pointed to genetic strain as a predisposing factor for IADE and CSVD. However, there have been few direct genetic studies aimed towards determining the association between IADE and CSVD. In the future, more clinical and basic research studies are needed to elucidate the causal relationship between IADE and CSVD and the related molecular and genetic mechanisms.