Invited Mini Review : Polymer materials for enzyme immobilization and their application in bioreactors

( Yan Fang ),( Xiao Jun Huang ),( Peng Cheng Chen ),( Zhi Kang Xu ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.2

Enzymatic catalysis has been pursued extensively in a wide range of important chemical processes for their unparalleled selectivity and mild reaction conditions. However, enzymes are usually costly and easy to inactivate in their free forms. Immobilization is the key to optimizing the in-service performance of an enzyme in industrial processes, particularly in the field of non-aqueous phase catalysis. Since the immobilization process for enzymes will inevitably result in some loss of activity, improving the activity retention of the immobilized enzyme is critical. To some extent, the performance of an immobilized enzyme is mainly governed by the supports used for immobilization, thus it is important to fully understand the properties of supporting materials and immobilization processes. In recent years, there has been growing concern in using polymeric materials as supports for their good mechanical and easily adjustable properties. Furthermore, a great many work has been done in order to improve the activity retention and stabilities of immobilized enzymes. Some introduce a spacer arm onto the support surface to improve the enzyme mobility. The support surface is also modified towards biocompatibility to reduce non-biospecific interactions between the enzyme and support. Besides, natural materials can be used directly as supporting materials owning to their inert and biocompatible properties. This review is focused on recent advances in using polymeric materials as hosts for lipase immobilization by two different methods, surface attachment and encapsulation. Polymeric materials of different forms, such as particles, membranes and nanofibers, are discussed in detail. The prospective applications of immobilized enzymes, especially the enzyme-immobilized membrane bioreactors (EMBR) are also discussed. [BMB reports 2011; 44(2): 87-95]

Calculation of Deflection and Stress of Assembled Concrete Composite Beams under Shrinkage and Creep and Its Application in Member Design Optimization

Yan Fang,Jianghong Mao,Yixue Zhang,Weiliang Jin,Diwei Tang,Jun Zhang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.9

There are a large number of concrete bonding interfaces in assembled concrete structures. Moreover, the problems of deformation and coordination at the interfaces lead to weak bonding under shrinkage and creep. The theoretical methods and analytical solutions for the long-term performance of composite structures in recent literatures are relatively complicated for the review or optimization in the design stage. Hence, a method for calculating the mid-span deflection of and the cross-sectional stress on composite beams under shrinkage and creep was developed based on the average curvature method. The calculation method was then verified by the experiments and the numerical simulations. Further, factors affecting the deflection of and the stress on the assembled concrete composite beams, including the loading age, the reinforcement ratio, the section dimensions, and the surface area in contact with the atmosphere were analyzed by using the developed method. The results revealed that the adjustment of the section dimensions and the loading time is the effective optimization approach. A framework for review or optimization of composite concrete beams based on the sensitivity analysis is proposed and a case study is carried out. The results of this work can helpfully be used to control the risk of additional deflections or cracking during the long-term operation of buildings.

MODIFIED CONVOLUTIONAL NEURAL NETWORK WITH TRANSFER LEARNING FOR SOLAR FLARE PREDICTION

Yanfang Zheng,Xuebao Li,Xinshuo Wang,Ta Zhou 한국천문학회 2019 Journal of The Korean Astronomical Society Vol.52 No.6

We apply a modified Convolutional Neural Network (CNN) model in conjunction with transfer learning to predict whether an active region (AR) would produce a ≥C-class or ≥M-class are within the next 24 hours. We collect line-of-sight magnetogram samples of ARs provided by the SHARP from May 2010 to September 2018, which is a new data product from the HMI onboard the SDO. Based on these AR samples, we adopt the approach of shuffle-and-split cross-validation (CV) to build a database that includes 10 separate data sets. Each of the 10 data sets is segregated by NOAA AR number into a training and a testing data set. After training, validating, and testing our model, we compare the results with previous studies using predictive performance metrics, with a focus on the true skill statistic (TSS). The main results from this study are summarized as follows. First, to the best of our knowledge, this is the first time that the CNN model with transfer learning is used in solar physics to make binary class predictions for both ≥C-class and ≥M-class ares, without manually engineered features extracted from the observational data. Second, our model achieves relatively high scores of TSS = 0.6400.075 and TSS = 0.5260.052 for ≥M-class prediction and ≥C-class prediction, respectively, which is comparable to that of previous models. Third, our model also obtains quite good scores in five other metrics for both ≥C-class and ≥M-class are prediction. Our results demonstrate that our modified CNN model with transfer learning is an effective method for are forecasting with reasonable prediction performance.

LARGE TIME-STEPPING METHOD BASED ON THE FINITE ELEMENT DISCRETIZATION FOR THE CAHN-HILLIARD EQUATION

Yanfang Yang,Xinlong Feng,Yinnian He 한국전산응용수학회 2011 Journal of applied mathematics & informatics Vol.29 No.5

In this paper, a class of large time-stepping method based on the finite element discretization for the Cahn-Hilliard equation with the Neumann boundary conditions is developed. The equation is discretized by finite element method in space and semi-implicit schemes in time. For the first order fully discrete scheme, convergence property is investigated by using finite element analysis. Numerical experiment is presented, which demonstrates the effectiveness of the large time-stepping approaches.

GPU-ACCELERATED SPECKLE MASKING RECONSTRUCTION ALGORITHM FOR HIGH-RESOLUTION SOLAR IMAGES

Yanfang Zheng,Xuebao Li,Huifeng Tian,Qiliang Zhang,Chong Su,Lingyi Shi,Ta Zhou 한국천문학회 2018 Journal of The Korean Astronomical Society Vol.51 No.3

The near real-time speckle masking reconstruction technique has been developed to accelerate the processing of solar images to achieve high resolutions for ground-based solar telescopes. However, the reconstruction of solar subimages in such a speckle reconstruction is very time-consuming. We design and implement a new parallel speckle masking reconstruction algorithm based on the Compute Unified Device Architecture (CUDA) on General Purpose Graphics Processing Units (GPGPU). Tests are performed to validate the correctness of our program on NVIDIA GPGPU. Details of several parallel reconstruction steps are presented, and the parallel implementation between various modules shows a significant speed increase compared to the previous serial implementations. In addition, we present a comparison of runtimes across serial programs, the OpenMP-based method, and the new parallel method. The new parallel method shows a clear advantage for large scale data processing, and a speedup of around 9 to 10 is achieved in reconstructing one solar subimage of 256$\times$256 pixels. The speedup performance of the new parallel method exceeds that of OpenMP-based method overall. We conclude that the new parallel method would be of value, and contribute to real-time reconstruction of an entire solar image.

Nitric Oxide Alleviates Deterioration and Preserves Antioxidant Properties in ‘Tainong’ Mango Fruit During Ripening

Yanfang Ren,Junyu He,Houyu Liu,Guoqing Liu,Xiaoling Ren 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.1

We investigated the effects of nitric oxide (NO) on quality, membrane lipid peroxidation, and antioxidantenzymes in mango (Mangifera indica L. cv ‘Tainong’) fruit during ripening. Fruits were treated with 0.25 mmol·L-1sodium nitroprusside (SNP) by the immersion method and stored at 23°C for 20 days. SNP treatment significantlysuppressed the respiration rate, enhanced fruit firmness, and decreased the rot index, peel color index, and weightloss in the fruit. This treatment also slowed the increase in soluble solids content (SSC) while maintaining highlevels of titratable acidity (TA), ascorbic acid (AsA), and phenolic compounds. Furthermore, SNP treatment enhancedthe antioxidant activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and reduced theactivities of lipoxygenase (LOX) and polyphenol oxidase (PPO) in mango fruit, which was associated with the reducedaccumulation of malondialdehyde (MDA), superoxide anion radical (O2•-), and hydrogen peroxide (H2O2) comparedwith the control. Therefore, the addition of exogenous SNP has the potential for improving quality and prolongingthe shelf life of mango fruits by protecting them against oxidative damage caused by ROS during ripening.

Facile Preparation of Polymer-Grafted Halloysite Nanotubes via a Redox System: a Novel Approach to Construct Antibacterial Hydrogel

Yanfang Ma,Zhihang Zhao,Boyan Tang,Yonggang Wu,Hailei Zhang 한국고분자학회 2020 Macromolecular Research Vol.28 No.10

We demonstrate the use of a supernormal valence transition-metal (Ce(IV) and Cu(III))-mediated redox system for the surface grafting on the halloysite nanotubes (HNTs). Following this way, commonly-used vinyl monomers were grafted on HNTs in one step under mild condition. The grafting was evidenced using FTIR, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The micromorphology was carefully characterized by transmission electron microscope (TEM). The results indicate that the surface grafting reaction was successfully processed in all cases, in which the Ce(IV) shows a much higher initiation activity than that of Cu(III). Then a uniform hydrogel was constructed by mixing poly(triethyl(4-vinylbenzyl)phosphonium chloride-grafted HNTs (HNTs-P(Et-P)) with sodium polyacrylate-grafted HNTs (HNTs-P(AA-Na)), which show desirable antibacterial activity.

Non-parameter Estimation of Failures Intensity of Tractor Based on Bootstrap

Yanfang Wang,Changlin Ao 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.1

Numerical analysis of thermal dynamics and mixing performance in the blade-type static mixers

Yanfang Yu,Yaxin Chen,Huibo Meng,Yunjuan Yao,Dongzhou Liu,Jianhua Wu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

The turbulent thermal dynamics and mixing performance of kenics static mixer (KSM), lightnin static mixer (LSM) and Q-type static mixer (QSM) were numerically simulated with uniform heat flux within the range of Reynolds numbers (Re) between 6000 and 30000. The numerical predictions of Nusselt number (Nu) and friction coefficient (f) in KSM were well consistent with the experimental data. The dean vortices, thermal resistance, entropy generation and field synergy were fully analyzed to obtain the enhancement mechanism of heat transfer performance. The synergy performance between temperature gradient and flow field firstly decreased and then increased and are superior to that of KSM with increasing Re. With the same Re, the entropy generation rates of LSM are 0.93-0.94 times that of QSM. LSM is a better alternative consideration for convection mixing and heat transfer enhancement. Two new relationships between Nu and f under different dimensionless uniform heat flux are obtained.

Development of Primary Core Collection of Japanese Persimmon from China ( Diospyros kaki Thunb.) by Stepwise Clustering

Yanfang Zhang,Qinglin Zhang,Yong Yang,Zhengrong Luo 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-