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Expression and characterization of a CALB-type lipase from

Jiang-Wei Shen, Xue Cai, Bao-Juan Dou, Feng-Yu Qi, Xiao-Jian Zhang, Zhi-Qiang Liu, Yu-Guo Zheng

《化学科学与工程前沿(英文)》 2020年 第14卷 第5期   页码 868-879 doi: 10.1007/s11705-019-1889-x

摘要: A lipase from SRZ2 (SRL) with 73% amino acid sequence identity to lipase B (CALB) was cloned and overexpressed in . The recombinant SRL showed a preference for short-chain -nitrophenyl esters. It achieved maximum activity at pH 8.0 and 65°C for -nitrophenyl hexanoate (C6) with and / values of 0.14 mmol∙L and 1712 min ∙mmol∙L at 30°C, respectively. SRL displayed excellent thermostability and pH stability, retaining more than 79% of its initial activity after incubation at 60°C for 72 h and 75% at pH 3 to 11 for 72 h. It also maintained most of its activity in the presence of inhibitors and detergents except sodium dodecyl sulfate, and it tolerated organic solvents. SRL was covalently immobilized and successfully used for ethyl hexanoate synthesis in cyclohexane or in a solvent-free system with a high conversion yield (>95%). Furthermore, high conversion yield was also achieved for the synthesis of various short-chain flavor esters when high substrate concentrations of 2 mol∙L were applied. This study indicated that a CALB-type lipase from SRZ2 showed great potential in organic ester synthesis.

关键词: lipase     Sporisorium reilianum     biochemical characterization     short-chain flavor ester     solvent-free system    

Digital microfluidics: A promising technique for biochemical applications

He WANG, Liguo CHEN, Lining SUN

《机械工程前沿(英文)》 2017年 第12卷 第4期   页码 510-525 doi: 10.1007/s11465-017-0460-z

摘要:

Digital microfluidics (DMF) is a versatile microfluidics technology that has significant application potential in the areas of automation and miniaturization. In DMF, discrete droplets containing samples and reagents are controlled to implement a series of operations via electrowetting-on-dielectric. This process works by applying electrical potentials to an array of electrodes coated with a hydrophobic dielectric layer. Unlike microchannels, DMF facilitates precise control over multiple reaction processes without using complex pump, microvalve, and tubing networks. DMF also presents other distinct features, such as portability, less sample consumption, shorter chemical reaction time, flexibility, and easier combination with other technology types. Due to its unique advantages, DMF has been applied to a broad range of fields (e.g., chemistry, biology, medicine, and environment). This study reviews the basic principles of droplet actuation, configuration design, and fabrication of the DMF device, as well as discusses the latest progress in DMF from the biochemistry perspective.

关键词: digital microfluidics     electrowetting on dielectric     discrete droplet     biochemistry    

Potential of electron transfer and its application in dictating routes of biochemical processes associated

《医学前沿(英文)》 2021年 第15卷 第5期   页码 679-692 doi: 10.1007/s11684-021-0866-1

摘要: Metabolic reprogramming, such as abnormal utilization of glucose, addiction to glutamine, and increased de-novo lipid synthesis, extensively occurs in proliferating cancer cells, but the underneath rationale has remained to be elucidated. Based on the concept of the degree of reduction of a compound, we have recently proposed a calculation termed as potential of electron transfer (PET), which is used to characterize the degree of electron redistribution coupled with metabolic transformations. When this calculation is combined with the assumed model of electron balance in a cellular context, the enforced selective reprogramming could be predicted by examining the net changes of the PET values associated with the biochemical pathways in anaerobic metabolism. Some interesting properties of PET in cancer cells were also discussed, and the model was extended to uncover the chemical nature underlying aerobic glycolysis that essentially results from energy requirement and electron balance. Enabling electron transfer could drive metabolic reprogramming in cancer metabolism. Therefore, the concept and model established on electron transfer could guide the treatment strategies of tumors and future studies on cellular metabolism.

关键词: metabolic reprogramming     potential of electron transfer     cell proliferation     aerobic glycolysis     cancer metabolism    

Metabonomic study of the biochemical profiles of heterozygous myostatin knockout swine

Jianxiang XU,Dengke PAN,Jie ZHAO,Jianwu WANG,Xiaohong HE,Yuehui MA,Ning LI

《农业科学与工程前沿(英文)》 2015年 第2卷 第1期   页码 90-99 doi: 10.15302/J-FASE-2015045

摘要: Myostatin is a transforming growth factor-β family member that normally acts to limit skeletal muscle growth. Myostatin gene ( ) knockout (KO) mice show possible effects for the prevention or treatment of metabolic disorders such as obesity and type 2 diabetes. We applied chromatography and mass spectrometry based metabonomics to assess system-wide metabolic response of heterozygous KO ( ) swine. Most of the metabolic data for swine were similar to the data for wild type (WT) control swine. There were, however, metabolic changes related to fatty acid metabolism, glucose utilization, lipid metabolism, as well as BCAA catabolism caused by monoallelic depletion.The statistical analyses suggested that: (1) most metabolic changes were not significant in swine compared to WT swine; (2) only a few metabolic properties were significantly different between KO and WT swine, especially for lipid metabolism. Significantly, these minor changes were most evident in female KO swine and suggested differences in gender sensitivity to myostatin.

关键词: myostatin     transforming growth factor-β family     skeletal muscle     metabolic disorders     chromatography     mass spectrometry     metabonomics    

Uptake and accumulation of multiwalled carbon nanotubes change the morphometric and biochemical characteristics

Elena SMIRNOVA, Alexander GUSEV, Olga ZAYTSEVA, Olga SHEINA, Alexey TKACHEV, Elena KUZNETSOVA, Elena LAZAREVA, Galina ONISHCHENKO, Alexey FEOFANOV, Mikhail KIRPICHNIKOV

《化学科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 132-138 doi: 10.1007/s11705-012-1290-5

摘要: We have studied the effect of the engineered nanomaterial Taunit, containing multiwalled carbon nanotubes (MWCNTs), on the growth of seedlings and investigated whether affected plants uptake and accumulate MWCNTs. We found that 100 μg/mL and 1000 μg/mL of Taunit stimulated the growth of roots and stems, and enhanced the peroxidase activity in these parts of plants. Microscopy studies showed the presence of MWCNTs in the root and leaf tissues of seedlings exposed to Taunit, suggesting that MWCNTs have a capacity to penetrate the cell walls, accumulate in roots and translocate to the leaves. Thus the stimulating effect of MWCNTs on seedlings of may be associated with the primary uptake and accumulation of MWCNTs by plant roots followed by translocation to the other plant tissues.

关键词: multiwalled carbon nanotubes     plants     electron microscopy    

Mechanism and characterization of microplastic aging process: A review

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1700-6

摘要:

● Methods for estimating the aging of environmental micro-plastics were highlighted.

关键词: Microplastics     Aging     Degradation     Characterization     Mechanism    

Comparisons in subcellular and biochemical behaviors of cadmium between low-Cd and high-Cd accumulation

Meng XUE, Yihui ZHOU, Zhongyi YANG, Biyun LIN, Jiangang YUAN, Shanshan WU

《环境科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 226-238 doi: 10.1007/s11783-013-0582-4

摘要: Subcellular distributions and chemical forms of cadmium (Cd) in the leaves, stems and roots were investigated in low-Cd accumulation cultivars and high-Cd accumulation cultivars of pakchoi ( L.). Root cell wall played a key role in limiting soil Cd from entering the protoplast, especially in the low-Cd cultivars. The high-Cd cultivars had significantly higher leaf and stem Cd concentrations than the low-Cd cultivars in cell wall fraction, chloroplast/trophoplast fraction, organelle fraction and soluble fraction. In low-Cd cultivars, which were more sensitive and thus had greater physiological needs of Cd detoxification than high-Cd cultivars, leaf vacuole sequestrated higher proportions of Cd. Cd in the form of pectate/protein complexes (extracted by 1 mol·L NaCl) played a decisive role in Cd translocation from root to shoot, which might be one of the mechanisms that led to the differences in shoot Cd accumulation between the two types of cultivars. Furthermore, the formation of Cd-phosphate complexes (extracted by 2% HAc) was also involved in Cd detoxification within the roots of pakchoi under high Cd stress, suggesting that the mechanisms of Cd detoxification might be different between low- and high-Cd cultivars.

关键词: cadmium (Cd)     low-Cd cultivar     pakchoi (Brassica chinensis L.)     subcellular distribution     chemical forms    

难降解石化干法腈纶废水物化-生化耦合处理技术研究

田智勇,涂响,宋永会,辛旺,李法云

《中国工程科学》 2013年 第15卷 第3期   页码 80-87

摘要:

采用物化-生化耦合处理难降解石化干法腈纶废水,开展了以多技术协同O3高级氧化与多格室A/O型膜生物(MBR)反应器为核心工艺的小试与中试试验研究。结果表明,物化-生化技术的合理耦合可显著提高石化干法腈纶废水处理中化学耗氧量(COD)、氨氮和总氮(TN)去除效果;MBR-O3氧化-曝气生物滤池(BAF)集成试验工艺稳定运行工况下,其COD、氨氮和TN去除率分别可以达到90.0 %、95.0 %和80.0 %,出水平均浓度可分别控制在100.0 mg/L、5.0 mg/L和35.0 mg/L以下。另外,由于石化干法腈纶废水水质缺少一定的可生化有机碳源以及丙烯腈低聚物和含氮杂环类有机物的难生物降解性,因此在生物脱氮过程中,有机氮向无机氨氮转化的氨化步骤限制了整体工艺脱除总氮的效果。

关键词: 难降解     干法     腈纶废水     物化     生化     耦合处理    

BIOINSECTICIDES AS FUTURE MAINSTREAM PEST CONTROL AGENTS: OPPORTUNITIES AND CHALLENGES

《农业科学与工程前沿(英文)》 2022年 第9卷 第1期   页码 82-97 doi: 10.15302/J-FASE-2021404

摘要:

Bioinsecticides are naturally-occurring substances from different sources that control insect pests. Ideal bioinsecticides should have low toxicity to non-target organisms. They should also be easily degraded in sewage treatment works and natural environments, highly effective in small quantities and affect target pests only. Public concerns about possible side-effects of synthetic pesticides have accelerated bioinsecticide research and development. However, to develop bioinsecticides into mainstream products, their high production costs, short shelf-life and often uncertain modes of action need to be considered. This review summarizes current progress on bioinsecticides which are categorized as biochemical insecticides and their derivatives, plant-incorporated protectants, and microbial bioinsecticides. The current constraints that prevent bioinsecticides from being widely used are discussed and future research directions are proposed.

 

关键词: biochemical insecticide / bioinsecticide / microbial bioinsecticides / plant-incorporated protectant / RNA insecticide    

An experimental characterization of human torso motion

Daniele CAFOLLA,I-Ming CHEN,Marco CECCARELLI

《机械工程前沿(英文)》 2015年 第10卷 第4期   页码 311-325 doi: 10.1007/s11465-015-0352-z

摘要:

The torso plays an important role in the human-like operation of humanoids. In this paper, a method is proposed to analyze the behavior of the human torso by using inertial and magnetic sensing tools. Experiments are conducted to characterize the motion performance of the human torso during daily routine operations. Furthermore, the forces acting on the human body during these operations are evaluated to design and validate the performance of a humanoid robot.

关键词: experimental biomechanics     human torso     analysis     inertial sensor     characterization    

Synthesis and characterization of norfloxacin biomonomer

Shengxiong DONG, Qiaoping CHEN, Hongfang XIE, Jianhua HUANG

《化学科学与工程前沿(英文)》 2011年 第5卷 第1期   页码 55-59 doi: 10.1007/s11705-010-0537-2

摘要: A novel drug agent named norfloxacin biomonomer was developed in order to solve the problem of low drug content, uneven drug distribution, low molecular weight, and wide molecular weight distribution of polymer drug, based on polyurethane, which was used as an antibacterial agent to control the bacterial infection associated with biofilm formation on polymeric materials used in biologic environments. In this research, norfloxacin biomonomer was synthesized by esterifying the compound of norfloxacin. High-performance liquid chromatography system was used to analyze the purity of the final product and intermediate products, and Fourier transform infrared spectrometer and mass spectrum were used to verify the final product and intermediate products. The results showed that the objective product was developed successfully. The final product of norfloxacin biomonomer could be incorporated into the polyurethane as chain extender.

关键词: norfloxacin     biomonomer     synthesis     characterization    

Microplastic and Nanoplastic Pollution: Characterization, Transport, Fate, and Remediation Strategies

《环境科学与工程前沿(英文)》 2022年 第16卷 第1期   页码 12-12 doi: 10.1007/s11783-021-1446-y

摘要: Plastics continues to have a critical and essential role in human society such as food packing, product packages and building materials. In the meantime, it has been recognized as a global sustainability priority to study and mitigate pollution of plastics and the associated unknown impacts from ultrafine plastic particles. Microplastic (<5 mm) particles, for instance, have been detected in the aquatic environment globally and have raised scientific interests and environmental concerns. Microplastics (MPs) can enter rivers through a variety of pathways (e.g., wastewater effluent, breakdown of plastic debris) and can negatively impact aquatic organisms through both direct injection with food and indirect contamination from absorbed toxins. MPs can absorb heavy metals, pathogens, and organic contaminants, mainly persistent organic pollutants (POPs) that can be ingested by organisms and introduced into the food web. Meanwhile, MPs may also release potentially toxic substances (e.g., plasticizers, flame retardants and antimicrobial agents) during weathering and degradation. An increasing number of papers are being published during the last years related to the effects of MPs as well as with synergistic effects when associated with MPs and their byproducts such as nanometer sized plastics or nanoplastics. This special issue successfully garnered a collection of research articles that addressed various topics of microplastic or nanoplastic pollution, characteristic, and environmental fate in the water environment. Particularly, this issue reported the seasonable occurrence and distribution of microplastics in different regions (e.g., China and India) from high-latitude nature reserve to sediments and coastal marine environments. Moreover, new sampling and analytical methodologies (e.g., fluorescent labeling) to identify MPs in diver matrixes (e.g., wastewater, sediment, and biota) are critically reviewed. The information is critical for scientists, business leaders, legislators, and the public are to explore and develop solutions that lessen society’s plastic footprint. We thank all authors, reviewers, and editorial staff of FESE for their efforts and contributions to this special issue. Guest Editors: Wen Zhang Department of Civil and Environmental Engineering, New Jersey Institute of Technology (wen.zhang@njit.edu) Melissa Pasquinelli College of Natural Resources, North Carolina State University (melissa_pasquinelli@ncsu.edu) Yang Li School of the Environment Beijing Normal University (liyang_bnu@bnu.edu.cn)

Comprehensive kinetostatic modeling and morphology characterization of cable-driven continuum robots

《机械工程前沿(英文)》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0756-0

摘要: In-situ maintenance is of great significance for improving the efficiency and ensuring the safety of aero-engines. The cable-driven continuum robot (CDCR) with twin-pivot compliant mechanisms, which is enabled with flexible deformation capability and confined space accessibility, has emerged as a novel tool that aims to promote the development of intelligence and efficiency for in-situ aero-engine maintenance. The high-fidelity model that describes the kinematic and morphology of CDCR lays the foundation for the accurate operation and control for in-situ maintenance. However, this model was not well addressed in previous literature. In this study, a general kinetostatic modeling and morphology characterization methodology that comprehensively contains the effects of cable-hole friction, gravity, and payloads is proposed for the CDCR with twin-pivot compliant mechanisms. First, a novel cable-hole friction model with the variable friction coefficient and adaptive friction direction criterion is proposed through structure optimization and kinematic parameter analysis. Second, the cable-hole friction, all-component gravities, deflection-induced center-of-gravity shift of compliant joints, and payloads are all considered to deduce a comprehensive kinetostatic model enabled with the capacity of accurate morphology characterization for CDCR. Finally, a compact continuum robot system is integrated to experimentally validate the proposed kinetostatic model and the concept of in-situ aero-engine maintenance. Results indicate that the proposed model precisely predicts the morphology of CDCR and outperforms conventional models. The compact continuum robot system could be considered a novel solution to perform in-situ maintenance tasks of aero-engines in an invasive manner.

关键词: kinetostatic modeling     morphology characterization     variable friction     continuum robots     in-situ maintenance    

Preparation and characterization of ZnO/ZnS hybrid photocatalysts via microwave-hydrothermal method

ZHAO Jinglian, WANG Xinping, ZHAO Liang

《环境科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 415-420 doi: 10.1007/s11783-008-0056-2

摘要: The photocatalytic performance of ZnO/ZnS hybrid nanocomposite was largely higher than that of the mere ZnO or ZnS nanoparticles, but the complicated procedure and misdistribution of final products limited its large-scale productions. The exploration of a novel synthesis route of ZnO/ZnS hybrid photocatalysts with high catalytic performance is becoming a crucial step for the large-scale application of ZnO/ZnS hybrid photocatalytic technique. Preparation and characterization of nanosized ZnO/ZnS hybrid photocatalysts were studied in this paper. The photocatalysts were obtained via microwave-hydrothermal crystallization with the help of sodium citrate. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), particle size distribution (PSD), and Fourier transformed infrared spectroscopy (FT-IR). The results indicated that so-synthesized ZnO/ZnS samples consisted of the high pure cubic (sphalerite) ZnS and hexagonal ZnO nanocrystallines with a narrow particle size distribution. The possible formation mechanisms of ZnO/ZnS nanocrystallines were mainly attributed to the superficially protective effect of citrate. The photocatalytic experiments demonstrated that the ZnO/ZnS photocatalysts exhibited a higher catalytic activity for the degradation of acid fuchsine than other monocomponents.

关键词: large-scale     hexagonal     misdistribution     characterization     nanocomposite    

Mechanical properties characterization of different types of masonry infill walls

André FURTADO, Hugo RODRIGUES, António ARÊDE, Humberto VARUM

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 411-434 doi: 10.1007/s11709-019-0602-y

摘要: It is remarkable, the recent advances concerning the development of numerical modeling frameworks to simulate the infill panels’ seismic behavior. However, there is a lack of experimental data of their mechanical properties, which are of full importance to calibrate the numerical models. The primary objective of this paper is to present an extensive experimental campaign of mechanical characterization tests of infill masonry walls made with three different types of masonry units: lightweight vertical hollow concrete blocks and hollow clay bricks. Four different types of experimental tests were carried out, namely: compression strength tests, diagonal tensile strength tests, and flexural strength tests parallel and perpendicular to the horizontal bed joints. A total amount of 80 tests were carried out and are reported in the present paper. The second objective of this study was to compare the mechanical properties of as-built and existing infill walls. The results presented and discussed herein, will be in terms of strain-stress curves and damages observed within the tests. It was observed a fragile behavior in the panels made with hollow clay horizontal bricks, without propagation of cracks. The plaster increased the flexural strength by 57%.

关键词: masonry infill walls     experimental characterization     compression strength     shear diagonal strength     flexural strength    

标题 作者 时间 类型 操作

Expression and characterization of a CALB-type lipase from

Jiang-Wei Shen, Xue Cai, Bao-Juan Dou, Feng-Yu Qi, Xiao-Jian Zhang, Zhi-Qiang Liu, Yu-Guo Zheng

期刊论文

Digital microfluidics: A promising technique for biochemical applications

He WANG, Liguo CHEN, Lining SUN

期刊论文

Potential of electron transfer and its application in dictating routes of biochemical processes associated

期刊论文

Metabonomic study of the biochemical profiles of heterozygous myostatin knockout swine

Jianxiang XU,Dengke PAN,Jie ZHAO,Jianwu WANG,Xiaohong HE,Yuehui MA,Ning LI

期刊论文

Uptake and accumulation of multiwalled carbon nanotubes change the morphometric and biochemical characteristics

Elena SMIRNOVA, Alexander GUSEV, Olga ZAYTSEVA, Olga SHEINA, Alexey TKACHEV, Elena KUZNETSOVA, Elena LAZAREVA, Galina ONISHCHENKO, Alexey FEOFANOV, Mikhail KIRPICHNIKOV

期刊论文

Mechanism and characterization of microplastic aging process: A review

期刊论文

Comparisons in subcellular and biochemical behaviors of cadmium between low-Cd and high-Cd accumulation

Meng XUE, Yihui ZHOU, Zhongyi YANG, Biyun LIN, Jiangang YUAN, Shanshan WU

期刊论文

难降解石化干法腈纶废水物化-生化耦合处理技术研究

田智勇,涂响,宋永会,辛旺,李法云

期刊论文

BIOINSECTICIDES AS FUTURE MAINSTREAM PEST CONTROL AGENTS: OPPORTUNITIES AND CHALLENGES

期刊论文

An experimental characterization of human torso motion

Daniele CAFOLLA,I-Ming CHEN,Marco CECCARELLI

期刊论文

Synthesis and characterization of norfloxacin biomonomer

Shengxiong DONG, Qiaoping CHEN, Hongfang XIE, Jianhua HUANG

期刊论文

Microplastic and Nanoplastic Pollution: Characterization, Transport, Fate, and Remediation Strategies

期刊论文

Comprehensive kinetostatic modeling and morphology characterization of cable-driven continuum robots

期刊论文

Preparation and characterization of ZnO/ZnS hybrid photocatalysts via microwave-hydrothermal method

ZHAO Jinglian, WANG Xinping, ZHAO Liang

期刊论文

Mechanical properties characterization of different types of masonry infill walls

André FURTADO, Hugo RODRIGUES, António ARÊDE, Humberto VARUM

期刊论文