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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    

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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    

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Observation on therapeutic efficacy of ursodeoxycholic acid in Chinese patients with primary biliary cirrhosis: a 2-year follow-up study

null

《医学前沿（英文）》 2013年 第7卷 第2期   页码 255-263 doi: 10.1007/s11684-012-0227-1

摘要：

The efficacy of ursodeoxycholic acid (UDCA) on long-term outcome of primary biliary cirrhosis (PBC) has been less documented in Chinese cohort. We aimed to assess the therapeutic effect of UDCA on Chinese patients with PBC. In the present study, 67 patients with PBC were treated with UDCA (13–15 mg?kg-1?day-1) and followed up for 2 years to evaluate the changes of symptoms, laboratory values and histological features. As the results indicated, fatigue and pruritus were obviously improved by UDCA, particularly in patients with mild or moderate symptoms. The alkaline phosphatase and γ-glutamyl transpetidase levels significantly declined at year 2 comparing to baseline values, with the most profound effects achieved in patients at stage 2. The levels of alanine aminotransferase and aspartate aminotransferase significantly decreased whereas serum bilirubin and immunoglobulin M levels exhibited no significant change. Histological feature was stable in patients at stages 1–2 but still progressed in patients at stages 3–4. The biochemical response of patients at stage 2 was much better than that of patients at stages 3–4. These data suggest that, when treated in earlier stage, patients in long-term administration of UDCA can gain favorable results not only on symptoms and biochemical responses but also on histology. It is also indicated that later histological stage, bad biochemical response and severe symptom may be indicators of poor prognosis for UDCA therapy.

关键词： primary biliary cirrhosis     ursodeoxycholic acid     Chinese     biochemical response     therapeutic efficacy    

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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    

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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    

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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    

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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    

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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    

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Development of a seismic design method based on response spectra for building structures

ZHOU Xiyuan, YU Ruifang

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 129-141 doi: 10.1007/s11709-007-0014-2

摘要： The assumption and problem of the mode-superposition response spectrum method in seismic design code is discussed based on a brief review of the development of the seismic design method for building structures. The scope of application for the classical damping theory is analyzed and the necessity of the research on mode-superposition method for non-classical damping is presented. The progresses on the mode superposition response spectrum theory are discussed. This includes: 1) the complex mode superposition method (in real form) for the non-classically damped linear system and the general calculation formula for the application of code; 2) the complex complete quadratic combination (CCQC) method for the non-classically damped linear system, which is based on the same assumptions as in deducing the complete quadratic combination (CQC) method which is popularly used in seismic design codes of many countries; 3) the complex complete quadratic combination with three components (CCQC3) method, which is a generalization of the CCQC method to the case of multi-components and multiple-support seismic excitations and deducing corresponding method; 4) the approach for calculation of seismic response of the non-classically damped system with overcritical damping and the calculation method of seismic response for the linear system with multiple eigenvalues; 5) the time-dependent CCQC (t) algorithm considering nonstationary earthquake ground motion; 6) an applied and effective method to solve the low order complex vector basis for the large linear non-classically damped system, which can be expediently used in practice to avoid the unknown errors coming from the forced uncoupling method; 7) bringing forward the concept of partial quadratic combination in order to reduce the calculation amount of CQC and CCQC methods, and studying the primary estimation-criterion. The reasonability and applicable scope of these methods are also briefly discussed in this paper.

关键词： generalization     classical damping     mode-superposition response     calculation formula     damping theory    

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Temporal changes in the characteristics of algae in Dianchi Lake, Yunnan Province, China

Ruixia SHEN,Chunyan TIAN,Zhidan LIU,Yuanhui ZHANG,Baoming LI,Haifeng LU,Na DUAN

《农业科学与工程前沿（英文）》 2015年 第2卷 第3期   页码 266-275 doi: 10.15302/J-FASE-2015064

摘要： Algal blooms have become a worldwide environmental concern due to water eutrophication. Dianchi Lake in Yunnan Province, China is suffering from severe eutrophication and is listed in the Three Important Lakes Restoration Act of China. Hydrothermal liquefaction allows a promising and direct conversion of algal biomass into biocrude oil. In this study, algal samples were collected from Dianchi Lake after a separation procedure including dissolved air flotation with polyaluminum chloride and centrifugation during four months, April, June, August and October. The algal biochemical components varied over the period; lipids from 0.7% to 2.1% ash-free dry weight (afdw), protein from 20.9% to 33.4% afdw and ash from 36.6% to 45.2% dry weight. The algae in June had the highest lipid and protein concentrations, leading to a maximum biocrude oil yield of 24.3% afdw. Biodiversity analysis using pyrosequencing revealed different distributions of microbial communities, specifically in April (89.0%), June (63.7%) and August (84.0%), and in April (2.2%), June (12.0%) and August (1.0%). This study demonstrated remarkable temporal changes in the biochemical composition and biodiversity of algae harvested from Dianchi Lake and changes in biocrude oil production potential.

关键词： algal blooms     temporal change     biochemical property     biodiversity     hydrothermal liquefaction    

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Confining pressure effect on dynamic response of high rockfill dam

Xuexing CAO, Yunlong HE, Kun XIONG,

《结构与土木工程前沿（英文）》 2010年 第4卷 第1期   页码 116-126 doi: 10.1007/s11709-010-0014-5

摘要： Studies show that the dynamic properties of rockfill are strongly dependent on the confining pressure. Therefore, confining pressure effect has become a very important factor in the seismic analysis of high rockfill dam. The relationships of dynamic shear modulus versus dynamic shear strain and damping ratio versus dynamic shear strain had been improved to a certain degree on the basic of widely used Hardin-Drnevich constitutive model in this paper. Then a new model that could consider confining pressure effect has been established. Regression analysis was carried out of the dynamic triaxial experimental data of the damming materials in the Changheba hydropower station of Sichun Province, China. The results show that, the new model can fit the test data well under various confining pressures. A corresponding computational procedure was compiled and applied in the dynamic response analysis of the Changheba Dam. Comparing the calculation results between the new constitutive model and the ordinary Hardin-Drnevich model, it can be seen that the result is conservative to some extent without considering confining pressure effect.

关键词： confining pressure effect     high rockfill dam     dynamic response     Hardin-Drnevich constitutive model    

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Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 593-606 doi: 10.1007/s11465-021-0636-4

摘要： This paper proposes a novel method for the continuum topology optimization of transient vibration problem with maximum dynamic response constraint. An aggregated index in the form of an integral function is presented to cope with the maximum response constraint in the time domain. The density filter solid isotropic material with penalization method combined with threshold projection is developed. The sensitivities of the proposed index with respect to design variables are conducted. To reduce computational cost, the second-order Arnoldi reduction (SOAR) scheme is employed in transient analysis. Influences of aggregate parameter, duration of loading period, interval time, and number of basis vectors in the SOAR scheme on the final designs are discussed through typical examples while unambiguous configuration can be achieved. Through comparison with the corresponding static response from the final designs, the optimized results clearly demonstrate that the transient effects cannot be ignored in structural topology optimization.

关键词： topology optimization     solid isotropic material with penalization     transient response     aggregation function     second-order Arnoldi reduction    

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Dynamic response of precast segmental bridge columns under heavy truck impact

《结构与土木工程前沿（英文）》 2023年 第17卷 第3期   页码 327-349 doi: 10.1007/s11709-023-0911-z

摘要： Considering the wide application of precast segmental bridge columns (PSBCs) in engineering practice, impact-resistant performance has gained significant attention. However, few studies have focused on PSBCs subjected to high-energy impacts caused by heavy truck collisions. Therefore, the behavior of PSBCs under a heavy truck impact was investigated in this study using high-fidelity finite element (FE) models. The detailed FE modeling methods of the PSBCs and heavy trucks were validated against experimental tests. The validated modeling methods were employed to simulate collisions between PSBCs and heavy trucks. The simulation results demonstrated that the engine and cargo caused two major peak impact forces during collision. Subsequently, the impact force, failure mode, displacement, and internal force of the PSBCs under heavy truck impacts were scrutinized. An extensive study was performed to assess the influence of the section size, truck weight, impact velocity, and number of precast segments on the impact responses. The truck weight was found to have a minor effect on the engine impact force. Damage was found to be localized at the bottom of the three segments, with the top remaining primarily undamaged. This parametric study demonstrated that larger cross-sections may be a preferred option to protect PSBCs against the impact of heavy trucks.

关键词： precast segmental bridge columns     heavy truck     collision     dynamic response    

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Dynamic response surface methodology using Lasso regression for organic pharmaceutical synthesis

《化学科学与工程前沿（英文）》 2022年 第16卷 第2期   页码 221-236 doi: 10.1007/s11705-021-2061-y

摘要： To study the dynamic behavior of a process, time-resolved data are collected at different time instants during each of a series of experiments, which are usually designed with the design of experiments or the design of dynamic experiments methodologies. For utilizing such time-resolved data to model the dynamic behavior, dynamic response surface methodology (DRSM), a data-driven modeling method, has been proposed. Two approaches can be adopted in the estimation of the model parameters: stepwise regression, used in several of previous publications, and Lasso regression, which is newly incorporated in this paper for the estimation of DRSM models. Here, we show that both approaches yield similarly accurate models, while the computational time of Lasso is on average two magnitude smaller. Two case studies are performed to show the advantages of the proposed method. In the first case study, where the concentrations of different species are modeled directly, DRSM method provides more accurate models compared to the models in the literature. The second case study, where the reaction extents are modeled instead of the species concentrations, illustrates the versatility of the DRSM methodology. Therefore, DRSM with Lasso regression can provide faster and more accurate data-driven models for a variety of organic synthesis datasets.

关键词： data-driven modeling     pharmaceutical organic synthesis     Lasso regression     dynamic response surface methodology    

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Persistence of humoral and cellular immune response after SARS-CoV-2 infection: opportunities and challenges

Tangchun Wu

《医学前沿（英文）》 2020年 第14卷 第6期   页码 816-819 doi: 10.1007/s11684-020-0823-4

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标题 作者 时间 类型 操作

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

Observation on therapeutic efficacy of ursodeoxycholic acid in Chinese patients with primary biliary cirrhosis: a 2-year follow-up study

null

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

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

Development of a seismic design method based on response spectra for building structures

ZHOU Xiyuan, YU Ruifang

期刊论文

Temporal changes in the characteristics of algae in Dianchi Lake, Yunnan Province, China

Ruixia SHEN,Chunyan TIAN,Zhidan LIU,Yuanhui ZHANG,Baoming LI,Haifeng LU,Na DUAN

期刊论文

Confining pressure effect on dynamic response of high rockfill dam

Xuexing CAO, Yunlong HE, Kun XIONG,

期刊论文

Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

期刊论文

Dynamic response of precast segmental bridge columns under heavy truck impact

期刊论文

Dynamic response surface methodology using Lasso regression for organic pharmaceutical synthesis

期刊论文

Persistence of humoral and cellular immune response after SARS-CoV-2 infection: opportunities and challenges

Tangchun Wu

期刊论文