Modeling and optimization of lipase-catalyzed esterification of policosanols with conjugated linoleic acid by response surface methodology

Zhao, Tingting,Ha, Tae-Yeoul,Lee, Junsoo,Kim, Byung Hee,Kim, In-Hwan Informa Healthcare 2013 Biocatalysis and biotransformation Vol.31 No.2

<P>The aim of this study was to model the lipase-catalyzed esterification of policosanols with conjugated linoleic acid (CLA) in a solvent-free system to produce wax esters which had a lower melting point than that of their corresponding policosanol forms and to optimize the reaction conditions by response surface methodology (RSM). Novozym 435 was selected as a suitable biocatalyst for the reaction. The molar ratio of substrates (policosanols to CLA) was 1:2. A well-fitting quadratic polynomial regression model for the degree of esterification (DE) of policosanols with CLA was established with regard to temperature (35-65°C), enzyme loading (1-5% of weight of total substrates), and reaction time (10-50 min). Optimal reaction conditions were 61.3°C for temperature, 3.7% for enzyme loading, and 34.1 min for reaction time, and the DE was ˜ 95 mol% under these conditions. The policosanols and wax esters synthesized under optimal conditions had melting points of 79°C and 57°C, respectively.</P>

Benefits of procyanidins on gut microbiota in Bama minipigs and implications in replacing antibiotics

Tingting Zhao,Xiaojuan Shen,Chang Dai,Li Cui 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.6

Several studies have reported the effect of absorption of procyanidins and their contribution to the small intestine. However, differences between dietary interventions of procyanidins and interventions via antibiotic feeding in pigs are rarely reported. Following 16S rRNA gene Illumina MiSeq sequencing, we observed that both procyanidin administration for 2 months (procyanidin-1 group) and continuous antibiotic feeding for 1 month followed by procyanidin for 1 month (procyanidin-2 group) increased the number of operational taxonomic units, as well as the Chao 1 and ACE indices, compared to those in pigs undergoing antibiotic administration for 2 months (antibiotic group). The genera Fibrobacter and Spirochaete were more abundant in the antibiotic group than in the procyanidin-1 and procyanidin-2 groups. Principal component analysis revealed clear separations among the three groups. Additionally, using the online Molecular Ecological Network Analyses pipeline, three co-occurrence networks were constructed; Lactobacillus was in a co-occurrence relationship with Trichococcus and Desulfovibrio and a co-exclusion relationship with Bacillus and Spharerochaeta. Furthermore, metabolic function analysis by phylogenetic investigation of communities by reconstruction of unobserved states demonstrated modulation of pathways involved in the metabolism of carbohydrates, amino acids, energy, and nucleotides. These data suggest that procyanidin influences the gut microbiota and the intestinal metabolic function to produce beneficial effects on metabolic homeostasis.

Lipase-Mediated Synthesis of Fatty Acid Esters Using a Blending Alcohol Consisting of Methanol and 1-Butanol

Zhao, TingTing,Choi, Nakyung,Kim, Heejin,Kim, Yangha,Kim, Hak-Ryul,Kim, In-Hwan Springer New York LLC 2017 Journal of the American Oil Chemists' Society Vol. No.

<P>Lipase-mediated transesterification of soybean oil with a blending alcohol consisting of methanol and 1-butanol for synthesis of fatty acid esters was carried out. Lipase from Thermomyces lanuginosa (Lipozyme TL IM) was used as a biocatalyst. The lipase was purchased from Novozymes (Seoul, Republic of Korea). The effects of the molar proportions of methanol and 1-butanol in the blending alcohol, reaction temperature, enzyme loading and water content were investigated, for reaction optimization. The relative consuming rates of methanol and 1-butanol during the reaction were also explored. Among seven different ratios of alcohol blends employed in this study, that containing 80 mol% methanol gave the highest yield of fatty acid esters. Optimum reaction temperature, enzyme loading, and water content were 30 A degrees C, 15% (based on the substrate weight), and 0.3% (based on the substrate weight), respectively. Water influenced significantly the reaction rate and yield. On the transesterification, the degree of reaction of methanol was higher than that of 1-butanol and the presence of 1-butanol contributed to increase of the reaction rate as well as yield. The maximum yield of ca. 98 wt% was achieved under the optimized condition.</P>

Hybrid Atmospheric Compensation in Free-Space Optical Communication

Tingting Wang,Xiaohui Zhao 한국광학회 2016 Current Optics and Photonics Vol.20 No.1

Since the direct-gradient (DG) method uses the Shack-Hartmann wave front sensor (SH-WFS), basedon the phase-conjugation principle, for atmospheric compensation in free-space optical (FSO) communication,it cannot effectively correct high-order aberrations. While the stochastic parallel gradient descent (SPGD)can compensate the distorted wave front, it requires more calculations, which is sometimes undesirablefor an FSO system. A hybrid compensation (HC) method is proposed by properly using the DG methodand SPGD algorithm to improve the performance of FSO communication. Simulations show that thismethod can well compensate wave-front aberrations and upgrade the coupling efficiency with fewcomputations, preferable correction results, and rapid convergence rate.

Nitrogen and Oxygen Co-doped Porous Carbon Fabric for Efficient Removal of Formaldehyde

Tingting Chen,Xiaosai Hu,Tao Zhao,Yuanyu Ge 한국섬유공학회 2022 Fibers and polymers Vol.23 No.7

Formaldehyde can pose a huge threat to human health due to its’ carcinogenic effect. Carbon materials asadsorbents are widely applied to remove formaldehyde hazards. However, most carbon materials with disadvantages of thelimited number of surface functional groups and the lack of suitable pore structure suffer from low adsorption rate for theadsorptive removal of formaldehyde. To improve the adsorption capability, oxygen (O) and nitrogen (N) elements co-dopedporous viscose-based activated carbon fiber (N-O-ACF) was prepared via oxidation-hydrothermal treatment. First of all, theO atom can be introduced into ACF through chemical oxidation. Then, with the help of the O atom bridging effect, N atomscan be efficiently incorporated into ACF, and the content of the N element is as high as 7.13 wt.%. Thus, an improvedadsorption performance of N-O-ACF for formaldehyde removal was achieved with the support of the synergistic effect of Nand O elements. The adsorption capacity of N-O-ACF for removing formaldehyde increased up to 226 mg g-1, while only161.5 mg g-1 was obtained for original ACF. The excellent formaldehyde adsorption capacity indicates that N-O-ACF may bea promising adsorbent in the field of indoor air purification.

On the Creative Design of Chinese Characters Centering on Compound characters

Zhao Yueyang,Cao Tingting 차세대컨버전스정보서비스학회 2021 디지털예술공학멀티미디어논문지 Vol.8 No.4

Compound characters refer to a new  form of characters created through the combination of two or more characters, that is, characters created by making use of the visual relationships between various characters and the symbiotic relationships between strokes, thus skillfully integrating familiar characters and symbols to create a new sense of unfamiliarity. compound characters are highly malleable and are with unique cultural values, historical values and artistic values. They have provided excellent design elements for the modern design of Chinese characters design and the philosophy of “turning many into one” reflected in compound characters is of referential value for modern designers. Therefore, this paper aims to explore how compound characters can be used  so that more diversified character images can be developed from Chinese characters in the modern context and to explore effective ideas of design. This paper first investigates the concept of compound characters and discusses their characters and types of visual composition. On that basis, by studying the application cases of compound characters in modern design, this paper discusses the application of compound characters in the innovative design of Chinese characters, as well as ideas of design ideas.

Energy-Saving for a Velocity Control System of a Pipe Isolation Tool Based on a Reinforcement Learning Method

Tingting Wu,Hong Zhao,Boxuan Gao,Fanbo Meng 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.1

The pipe isolation tool (PIT) demonstrates remarkable advantages in safety and efficiency compared with traditional plugging devices. However, its utilization in plugging operations is limited by the operation duration. In addition, the existing energy recovery system has low energy saving efficiency. In this paper, a real-time control energy-saving system of the PIT was designed based on a reinforcement learning algorithm. First, an experimental device for energy-saving was designed. Secondly, the energy distribution scheme of a hydraulic pump and accumulator based on experimental data was proposed. Finally, the reinforcement learning algorithm was used to adjust the opening of the hydraulic pump and the accumulator valves in real time during the plugging process to improving energy saving efficiency. The results verify that the energy saving efficiency of the PIT control system based on reinforcement learning could reach 23.71%, which satisfies the objectives of energy-saving and environmental applicability.

Acetaldehyde induces tau phosphorylation via activation of p38 MAPK/JNK and ROS production

Li Tingting,Shi Huahua,Zhao Yan 대한독성 유전단백체 학회 2022 Molecular & cellular toxicology Vol.18 No.3

Background Heavy drinking has been associated with increased risk of dementia such as Alzheimer’s disease, but the mechanisms are not fully understood. Evidence suggests that acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damages and cognitive dysfunction induced by the overconsumption of alcohol. Abnormal hyperphosphorylated tau protein is the major component of neurofi brillary tangle that correlates with neurodegeneration. However, there are few reports regarding whether acetaldehyde affects the phosphorylation of tau protein in neuronal cells. Objective The aim of this study is to explore the effect of acetaldehyde on the phosphorylation of tau protein. Results It was found that acetaldehyde treatment increased the amount of phosphorylated tau in human neuroblastoma SH-SY5Y cells. Further studies revealed that acetaldehyde increased the production of reactive oxygen species (ROS) and induced the activation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Pretreatment with antioxidant N -acetylcysteine (NAC) or inhibitors of p38 MAPK and JNK ameliorated the phosphorylation of tau in acetaldehyde treated cells, suggesting that acetaldehyde might increase the phosphorylation of tau via inducing the production of ROS and activating p38 MAPK and JNK pathways. Conclusion The result indicated that acetaldehyde treatment increased tau phosphorylation in neuronal cells. Therefore, the accumulation of acetaldehyde resulted from alcohol abuse or defect of acetaldehyde detoxification may promote tau pathology in neurodegenerative diseases such as AD.

중국 마가요 문양을 활용한 문화상품 디자인 개반에 대한 연구

조정정(Tingting Cao),조이양(Yueyang Zhao),안병진(Byoung Ahn) 한국디자인학회 2020 한국디자인학회 학술발표대회 논문집 Vol.2020 No.11

User Bias Drift Social Recommendation Algorithm based on Metric Learning

Jianli Zhao,Tingting Li,Shangcheng Yang,Hao Li,Baobao Chai 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.12

Social recommendation algorithm can alleviate data sparsity and cold start problems in recommendation system by integrated social information. Among them, matrix-based decomposition algorithms are the most widely used and studied. Such algorithms use dot product operations to calculate the similarity between users and items, which ignores user’s potential preferences, reduces algorithms’ recommendation accuracy. This deficiency can be avoided by a metric learning-based social recommendation algorithm, which learns the distance between user embedding vectors and item embedding vectors instead of vector dot-product operations. However, previous works provide no theoretical explanation for its plausibility. Moreover, most works focus on the indirect impact of social friends on user’s preferences, ignoring the direct impact on user’s rating preferences, which is the influence of user rating preferences. To solve these problems, this study proposes a user bias drift social recommendation algorithm based on metric learning (BDML). The main work of this paper is as follows: (1) the process of introducing metric learning in the social recommendation scenario is introduced in the form of equations, and explained the reason why metric learning can replace the click operation; (2) a new user bias is constructed to simultaneously model the impact of social relationships on user’s ratings preferences and user’s preferences; Experimental results on two datasets show that the BDML algorithm proposed in this study has better recommendation accuracy compared with other comparison algorithms, and will be able to guarantee the recommendation effect in a more sparse dataset.