Improved Enantioselective Hydrolysis of Racemic Ethyl-2,2- dimethylcyclopropanecarboxylate Catalyzed by Modified Novozyme 435

Fa-yong Liang,Jin Huang,Jun-yao He,Pu Wang 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.5

S-(+)-2,2-dimethylcyclopropanecarboxylic acid (S-(+)-DMCPA) is a key chiral intermediate for the synthesis of Cilastatin. The enzymatic preparation of S-(+)-DMCPA has attracted much attention. In order to improve the activity and stability of Novozyme 435 for enzymatic preparation of S-(+)-DMCPA from 2,2-dimethylcyclopropane carboxylate (DMCPE), the glutaraldehyde modification for Novozyme 435 was investigated and the glutaraldehydemodified Novozyme 435 was used as biocatalyst for the synthesis of S-(+)-DMCPA. The results showed that the modified Novozyme 435 had a better reusing merit than unmodified enzyme. The maximum specific activity was obtained by modification Novozyme 435 with 1.5%glutaraldehyde solution under the conditions of shaking at 200 rpm and 30oC for 45 min. The optimal enzymatic hydrolysis conditions for glutaraldehyde-modified Novozyme 435 were also confirmed. The optimized hydrolytic reaction mixture contained 10 mL potassium phosphate buffer (1.0 mol/L, pH 7.6), 90 mg of DMCPE and 160 mg of glutaraldehyde-modified enzyme, and the reaction was performed at 30oC and 200 rpm for 52 h. The reusing efficiency of modified Novozyme 435 was further evaluated. Under the optimal conditions, the modified enzyme remained 76.0% of its original yield after 10 times reuse,but the optical purity of the product kept intact; whereas the yield of unmodified enzyme reduced to 20.8% of its initial value and the ee value of product decreased a lot to 90.7% after 7 times recycle. These results showed that the modified Novozyme 435 was more cost-effective for the preparation of S-(+)-DMCPA in industrial application.

Pyoderma Gangrenosum in a Patient with X-Linked Agammaglobulinemia

( Qi Tan Fa-liang Ren ),( Hua Wang ) 대한피부과학회 2017 Annals of Dermatology Vol.29 No.4

X-linked agammaglobulinemia (XLA) is a primary im-munodeficiency disorder caused by germline mutations of B-cell tyrosine kinase (BTK) gene. It is characterized by de-creased serum immunoglobulins levels and circulating ma-ture B cells. This defect in humoral immunity leads to in-creased susceptibility to infection. Pyoderma gangrenosum (PG) is an uncommon, ulcerating, neutrophilic dermatosis. Here we report PG in an 8-year-old patient with XLA. The pa-tient received intravenous immunoglobulin treatment in conjunction with prednisone and topical application of 0.03% tacrolimus ointment and the ulcer was almost com-pletely healed in the 2 weeks of follow-up. The coexistence has been rarely reported. XLA may be a possible cofactor in the pathogenesis of PG. (Ann Dermatol 29(4) 476∼478, 2017)

ORiginal Article : Tryptase and Protease-Activated Receptor 2 Expression Levels in Irritable Bowel Syndrome

( Wen Jing Liang ),( Guo Zhang ),( He Sheng Luo ),( Lie Xin Liang ),( Dan Huang ),( Fa Can Zhang ) 대한간학회 2016 Gut and Liver Vol.10 No.3

Background/Aims: Previous studies have revealed that mast cells (MCs) may activate the protease-activated receptors and release of neuropeptides involved in the pathogenesis of irritable bowel syndrome (IBS). The levels of proteaseactivated receptor 2 (PAR-2) and tryptase can contribute to understanding the pathogenesis of IBS. Methods: Colonoscopic biopsies were performed of 38 subjects (20 with IBSdiarrhea [IBS-D], eight with IBS-constipation [IBS-C], and 10 healthy volunteers). The mRNA and protein levels of tryptase and PAR-2 were assessed by real-time PCR and Western blot. The levels of vasoactive intestinal peptide (VIP), substance P (SP), and calcitonin gene-related peptide (CGRP) were measured by immunohistochemistry, and MCs were counted by toluidine blue staining. Results: Significant increases in the mRNA expression of tryptase (p<0.05, IBS-D, IBS-C vs control) and PAR-2 (p<0.05, IBS-D, IBS-C vs control) and in the tryptase protein level (p<0.05, IBS-D, IBS-C vs control) were detected in IBS. Elevations of MCs, CGRP, VIP and SP (p<0.05, IBS-D vs control) were observed for IBS-D only. Conclusions: Tryptase levels may upregulate the function of PAR- 2, resulting in the release of neuropeptide and they were correlated with clinical symptoms associated with IBS. (Gut Liver 2016;10:382-390)

Confinement coefficient of concrete-filled square stainless steel tubular stub columns

Fa-Xing Ding,Yi-xiang Yin,Liping Wang,Yujie Yu,Liang Luo,Zhi-wu Yu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.4

The objective of this paper is to investigate the confinement coefficient of concrete-filled square stainless steel tubular (CFSSST) stub columns under axial loading. A fine finite 3D solid element model was established, which utilized a constitutive model of stainless steel considering the strain-hardening characteristics and a triaxial plastic-damage constitutive model of concrete with features of the parameter certainty under axial compression. The finite element analysis results revealed that the increased ultimate bearing capacity of CFSSST stub columns compared with their carbon steel counterparts was mainly due to that the composite action of CFSSST stub columns is stronger than that of carbon steel counterparts. A further parametric study was carried out based on the verified model, and it was found that the stress contribution of the stainless steel tube is higher than the carbon steel tube. The stress nephogram was simplified reasonably in accordance with the limit state of core concrete and a theoretical formula was proposed to estimate the ultimate bearing capacity of square CFSSST stub columns using superposition method. The predicted results showed satisfactory agreement with both the experimental and FE results. Finally, the comparisons of the experimental and predicted results using the proposed formula and the existing codes were illustrated.

Synthesis and Structural Studies of an Organic Complex and its Association with BSA

Fa-Yan Meng,Jin-Mei Zhu,Li Wang,Xue-Ping Zhong,Li-Xi Liang,Sheng-Rong Yu,Cui-Wu Lin 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

The self-assembly of one novel organic complex based on chlorogenic acid (HCA) and 2,2'-bipyridine (2,2'-bipy) has been synthesized and characterized. The complex achieved by hydrogen-bonding interactions,adopted a 1:1 stoichiometry in a solid state. The proton transfer occurred from the carboxyl oxygen to the aromatic nitrogen atom to form salts CA·(2,2'-Hbipy), the 2,2'-Hbipy molecule individually occupies the pseudo-tetragonum that is formed with CA. In this paper, the interactions of CA·(2,2'-Hbipy) with bovine serum albumin (BSA) were studied by fluorescence spectrometry. For CA·(2,2'-Hbipy), HCA and 2,2'-bipy,the average quenching constants for BSA were 2.4384 × 10^4, 4.653 × 10^3, and 3.059 × 10^3 L·mol^−1, respectively. The mechanism for protein fluorescence quenching is apparently governed by a static quenching process. The Stern-Volmer quenching constants and corresponding thermodynamic parameters ΔH, ΔG and ΔS were calculated. The binding constants and the number of binding sites were also investigated. The conformational changes of BSA were observed from synchronous fluorescence spectra.

Influence of stiffeners on the performance of blind-bolt end-plate connections to CFST columns

Fa-xing Ding,Zhi-cheng Pan,Peng Liu,Shi-jian Huang,Liang Luo,Tao Zhang 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.4

The paper aims to investigate the mechanical mechanism and seismic effect of stiffeners in blind bolt endplate connection to CFST column. A precise 3D finite element model with considering the cyclic properties of concrete and steel materials was established, and the efficiency was validated through monotonic and cyclic test data. The deforming pattern and the seismic performance of the unstiffened and stiffened blind bolt endplate connections were investigated. Then a parametric analysis was conducted to analyze the contribution of stiffeners and the joint working behaviors with endplate under cyclic load. The joint stiffness classifications were compared and a supplement stiffness classification method was proposed, and the energy dissipation ability of different class connections were compared and discussed. Results indicated that the main deformation pattern of unstiffened blind bolt endplate connections was the local bending of end plate. The vertical stiffeners can effectively alleviate the local bending deformation of end plate. And influence of stiffeners in thin endplate and thick endplate was different. Based on the stiffness of external diaphragm welded connection, a more detailed rigidity classification was proposed which included the pin, semi-rigid, quasi-rigid and rigid connection. Beam was the main energy dissipation source for rigid connection. For the semi-rigid and quasi-rigid connection, the extended endplate, stiffeners and steel beam would all participate in the energy dissipation.

Influence of rendering methods on yield and quality of chicken fat recovered from broiler skin

Liang-Kun Lin,Fa-Jui Tan 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: In order to utilize fat from broiler byproducts efficiently, it is necessary to develop an appropriate rendering procedure and establish quality information for the rendered fat. A study was therefore undertaken to evaluate the influence of rendering methods on the amounts and general properties of the fat recovered from broiler skin. Methods: The yield and quality of the broiler skin fat rendered through high and lower energy microwave rendering (3.6 W/g for 10 min and 2.4 W/g for 10 min for high power microwave rendering (HPMR) and high power microwave rendering (LPMR), respectively), oven baking (OB, at 180°C for 40 min), and water cooking (WC, boiling for 40 min) were compared. Results: Microwave-rendered skin exhibited the highest yields and fat recovery rates, followed by OB, and WC fats (p<0.05). HPMR fat had the highest L*, a*, and b* values, whereas WC fat had the highest moisture content, acid values, and thiobarbituric acid (TBA) values (p<0.05). There was no significant difference in the acid value, peroxide value, and TBA values between HPMR and LPMR fats. Conclusion: Microwave rendering at a power level of 3.6 W/g for 10 min is suggested base on the yield and quality of chicken fat.

Fast Thresholding Based on Improved Minimum Cross Entropy

Yong-Liang Zhang,Wen Zhang,Gang Xiao,Jia-Fa Mao,Shan-Shan Huang,Xiao-Wei Zheng 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Image segmentation is an important and classic problem in image processing and computer vision. Thresholding is applied to many fields, because of its less computation and stable performance. The key of thresholding method is to determine the adaptive threshold. In order to segment biological image effectively, a new adaptive thresholding method is proposed. First, two dimension minimum entropy is computed based on gray-gradient co-occurrence matrix; and then the genetic algorithm is applied to encode the two-dimension threshold vector; Finally, the optimum threshold is calculated based on fitness function and uniformity measurement(UM). Experimental results show that this method has three advantages: 1) improve computational efficiency so that it can run in real time; 2) retain more object and edge information so that it can meet the practical requirement; 3) robust to the uneven distribution of light.

Multiscale Belief Propagation on Concrete CT Image Fast Segmentation

Zhao Liang,Lu Jun,Chen Deng-feng,Li chang-hua,Dang Fa-ning 보안공학연구지원센터(IJGDC) 2013 International Journal of Grid and Distributed Comp Vol.6 No.6

Two New Acorane Sesquiterpenes from Illicium henryi

Tai-Fa Song,Wei-Dong Zhang,Xin-Hua Xia,Yun-Heng Shen,Chun-Mei Liu,Sheng Lin,Hui-zi Jin,Hui-Liang Li 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.9

Two new acorane sesquiterpenes, 10-hydroxyacoronene (1) and 1β-isopropyl-4β-methyl-9β-hydroxy spiro[4.5]dec-6-en-8-one (2), one new natural product, 4-hydroxy-4, 6-dimethyl-1-tetralone (3), and one known acorane sesquiterpene, acoradiepoxide (4) were isolated from the twigs and leaves of Illicium henryi. The structures of the new compounds were elucidated primarily on the basis of analysis of spectroscopic data. In addition, the inhibitory effect on NO production of these compounds were tested. Compounds 1 and 4 exhibited slight inhibitory effects on NO production with IC50 values of 82.4 μg/mL and 76.5 μg/mL, respectively.