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Bacteriophages in water pollution control: Advantages and limitations

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1378-y

摘要：

•Phages can be better indicators of enteric viruses than fecal indicator bacteria.

关键词： Phage     Water pollution monitoring     Harmful bacteria biocontrol     Horizontal gene transfer     Bacterial resistance    

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Assessment of antibiotic resistance genes in dialysis water treatment processes

Xuan Zhu, Chengsong Ye, Yuxin Wang, Lihua Chen, Lin Feng

《环境科学与工程前沿（英文）》 2019年 第13卷 第3期 doi: 10.1007/s11783-019-1136-1

摘要：

• Quantitative global ARGs profile in dialysis water was investigated.

• Totally 35 ARGs were found in the dialysis treatment train.

• 29 ARGs (highest) were found in carbon filtration effluent.

• erm and mtrD-02 occurred in the final effluent.

• The effluent was associated with health risks even after RO treatment.

关键词： Dialysis water     Treatment process     Antibiotic resistance gene     High-throughput quantitative PCR     Horizontal gene transfer    

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Natural convection heat transfer of water in a horizontal circular gap

SU Guanghui, WU Yingwei, Kenichiro Sugiyama

《能源前沿（英文）》 2007年 第1卷 第2期   页码 167-173 doi: 10.1007/s11708-007-0021-y

摘要： An experimental study on the natural convection heat transfer on a horizontal downward facing heated surface in a water gap was carried out under atmospheric pressure conditions. A total of 700 experimental data points were correlated using Rayleigh versus Nusselt number in various forms, based on different independent variables. The effects of different characteristic lengths and film temperatures were discussed. The results show that the buoyancy force acts as a resistance force for natural convection heat transfer on a downward facing horizontal heated surface in a confined space. For the estimation of the natural convection heat transfer under the present conditions, empirical correlations in which Nusselt number is expressed as a function of the Rayleigh number, or both Rayleigh and Prandtl numbers, may be used. When it is accurately predicted, the Nusselt number is expressed as a function of the Rayleigh and Prandtl numbers, as well as the gap width-to-heated surface diameter ratio; and uses the temperature difference between the heated surface and the ambient fluid in the definition of Rayleigh number. The characteristic length is the gap size and the film temperature is the average fluid temperature.

关键词： function     diameter     different independent     different characteristic     horizontal downward    

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Convective mass transfer from a horizontal rotating cylinder in a slot air jet flow

Hongting MA , Dandan MA , Na YANG ,

《能源前沿（英文）》 2009年 第3卷 第3期   页码 289-296 doi: 10.1007/s11708-009-0019-8

摘要： The effects of air jet impinging on the mass transfer characteristics from a rotating spinning cylinder surface were experimentally investigated. The effects of rotational Reynolds number

关键词： air jet impinging     rotating cylinder     critical point     mass transfer characteristics    

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Experimental study on heat transfer characteristics of supercritical carbon dioxide in horizontal tube

LV Jing, FU Meng, QIN Na, DONG Bin

《能源前沿（英文）》 2008年 第2卷 第3期   页码 339-343 doi: 10.1007/s11708-008-0045-y

摘要： The heat transfer characteristics of supercritical carbon dioxide in a horizontal tube with water in the vertical cross flow form were experimentally investigated. The results indicate that the changes of inlet pressure, mass flow rate, and cooling water flow rate have major effects on heat transfer performance. The variations of Reynolds number and Prandtl number were obtained in counter flow and vertical cross flow. The four conventional correlations for convection heat transfer of supercritical carbon dioxide were verified by the experimental data in this study and the correlation agree with this experimental condition was determined.

关键词： conventional     experimental condition     vertical     Reynolds number     transfer    

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Influences and mechanisms of nanofullerene on the horizontal transfer of plasmid-encoded antibiotic resistance

Qingkun Ji, Caihong Zhang, Dan Li

《环境科学与工程前沿（英文）》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1287-0

摘要： Abstract • Sub-inhibitory levels of nC60 promote conjugative transfer of ARGs. • nC60 can induce ROS generation, oxidative stress and SOS response. • nC60 can increase cell membrane permeability and alter gene expression. • Results provide evidence of nC60 promoting antibiotic resistance dissemination. The spread and development of antibiotic resistance globally have led to severe public health problems. It has been shown that some non-antibiotic substances can also promote the diffusion and spread of antibiotic resistance genes (ARGs). Nanofullerene (nC60) is a type of nanomaterial widely used around the world, and some studies have discovered both the biological toxicity and environmental toxicity of nC60. In this study, cellular and molecular biology techniques were employed to investigate the influences of nC60 at sub-minimum inhibitory concentrations (sub-MICs) on the conjugation of ARGs between the E. coli strains. Compared with the control group, nC60 significantly increased the conjugation rates of ARGs by 1.32‒10.82 folds within the concentration range of 7.03‒1800 mg/L. This study further explored the mechanism of this phenomenon, finding that sub-MICs of nC60 could induce the production of reactive oxygen species (ROS), trigger SOS-response and oxidative stress, affect the expression of outer membrane proteins (OMPs) genes, increase membrane permeability, and thus promote the occurrence of conjugation. This research enriches our understanding of the environmental toxicity of nC60, raises our risk awareness toward nC60, and may promote the more rational employment of nC60 materials.

关键词： Nanofullerene     Sub-minimum inhibitory concentrations     Antibiotic resistance genes     Conjugation     Molecular biological techniques    

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Experimental study on saturated flow boiling heat transfer of R290/R152a binary mixtures in a horizontal

Xin ZOU, Maoqiong GONG, Gaofei CHEN, Zhaohu SUN, Jianfeng WU

《能源前沿（英文）》 2010年 第4卷 第4期   页码 527-534 doi: 10.1007/s11708-010-0109-7

摘要： An experimental study on the saturated flow boiling heat transfer for a binary mixture of R290/R152a at various compositions is conducted at pressures ranging from 0.2 to 0.4 MPa. The heat transfer coefficients are experimentally measured over mass fluxes ranging from 74.1 to 146.5 kg/(m ·s) and heat fluxes ranging from 13.1 to 65.5 kW/m . The influences of different parameters such as quality, saturation pressure, heat flux, and mass flux on the local heat transfer coefficient are discussed. Existing correlations are analyzed. The Gungor-Winterton correlation shows the best fit among experimental data for the two pure refrigerants. A modified correlation for the binary mixture is proposed based on the authors’ previous work on pool boiling heat transfer and the database obtained from this study. The result shows that the total mean deviation is 10.41% for R290/R152a mixtures, with 97.6% of the predictions falling within±30%.

关键词： flow boiling     heat transfer     binary mixture     R290/R152a    

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Construction of lentiviral vector carrying Rab9 gene and its expression in mouse brain

Youguo HAO, Min ZHANG, Jinzhi XU, Bitao BU, Jiajun WEI

《医学前沿（英文）》 2009年 第3卷 第2期   页码 141-147 doi: 10.1007/s11684-009-0041-6

摘要： Rab proteins and their effectors facilitate vesicular transport by tethering donor vesicles to their respective target membranes. Rab9 mediates late endosome-to- -Golgi-network trafficking. To explore the possibility of Rab9-related gene therapy for neurodegenerative diseases, we packed Lentivirus encoding Rab9. The expressing plasmid pCDH1-MCF1-Rab9-EF1-copGFP was constructed by using molecular biological techniques. The Lentivirus encoding Rab9 cDNA was packed by Lifectamine-2000 mediated co-transfection of the plasmid pPACKH1- , pPACKH1- and pVSV- into 293T cells. DNA sequencing proved the successful construction of pCDH1-MCF1-Rab9-EF1-copGFP. After 72 hours, the expression of GFP could be detected in BV-2 cells. Western blotting revealed that the Rab9 gene expression in BALB/c mice brain was up-regulated significantly 4 weeks after injection with Lentivirus encoding Rab9, which evidenced a satisfactory increasing effect of this virus. Administration of Lenti-Rab9 to postnatal day 3 Niemann-Pick disease type C (NPC) mice reduced motor defects and prevented the weight loss associated with female NPC mice, as well as modulating the death rate of Purkinje neurons. It is concluded that the packaging of Lentivirus encoding Rab9 was successful. Lentivirus encoding Rab9 can increase the expression of Rab9 gene effectively, which might offer a novel means for the treatment of neurodegenerative diseases.

关键词： Rab9     lentivirus     gene therapy     gene transfer    

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Elimination of antibiotic resistance genes and control of horizontal transfer risk by UV-based treatment

Virender K. Sharma, Xin Yu, Thomas J. McDonald, Chetan Jinadatha, Dionysios D. Dionysiou, Mingbao Feng

《环境科学与工程前沿（英文）》 2019年 第13卷 第3期 doi: 10.1007/s11783-019-1122-7

摘要：

Antibiotic-resistant bacteria and antibiotic resistance genes are in water bodies.

UV/chlorination method is better to remove ARGs than UV or chlorination alone.

Research on UV/hydrogen peroxide to eliminate ARGs is forthcoming.

UV-based photocatalytic processes are effective to degrade ARGs.

关键词： Antibiotic resistance bacteria     Advanced oxidation processes     Disinfection     Reactive chlorine species     Sulfate radicals     Reactive oxygen species    

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Optimized human factor IX expression cassettes for hepatic-directed gene therapy of hemophilia B

null

《医学前沿（英文）》 2015年 第9卷 第1期   页码 90-99 doi: 10.1007/s11684-015-0390-2

摘要：

Gene therapy provides a potential cure for hemophilia B, and significant progress has been achieved in liver-directed gene transfer mediated by adeno-associated viral vectors. Recent clinical trials involving the use of a self-complementary adeno-associated virus serotype 8-human codon-optimized factor IX (AAV8-hFIXco) vector demonstrated encouraging efficacy with hFIX expression stabilized at 1% to 6% of normal level in patients, but safety concerns related to high vector doses are still present. Thus, further improvement of AAV vectors and hFIX expression cassette may positively contribute to the ultimate success of hemophilia B gene therapy. In this study, to obtain a higher expression level of hFIX that potentiates the coagulant capacity of recipients, human FIX expression vector was optimized by upgrading the codon adaption index and adjusting the GC content, inserting a Kozak sequence (GCCACC), and introducing a gain-of-function mutation, R338L (FIX Padua). The efficiency of the published and the presently constructed cassettes was compared through in vivo screening. In addition, the regulatory elements that control the FIX gene expression in these cassettes were screened for liver-specific effectiveness. Among all the constructed cassettes, scAAV-Pre-hFIXco-SIH-R338L, which was the construct under the control of the prothrombin enhancer and prealbumin promoter, resulted in the highest level of coagulant activity, and the expression levels of two constructed cassettes (scAAV-Chi-hFIXco-SIH-R338L and scAAV-Pre-hFIXco-SIH-R338L) were also higher than that of the published cassette (scAAV-LP1-hFIXco-SJ). In summary, our strategies led to a substantial increase in hFIX expression at the protein level or a remarkably elevated coagulant activity. Thus, these reconstructs of hFIX with AAV vector may potentially contribute to the creation of an efficacious gene therapy of hemophilia B.

关键词： factor IX     hemophilia B     liver-specific regulatory elements     hydrodynamic gene transfer    

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Matrix attachment regions included in a bicistronic vector enhances and stabilizes follistatin gene expressions

Xiaoming HU,Jing GUO,Chunling BAI,Zhuying WEI,Li GAO,Tingmao HU,Shorgan BOU,Guangpeng LI

《农业科学与工程前沿（英文）》 2016年 第3卷 第1期   页码 87-96 doi: 10.15302/J-FASE-2016087

摘要： In the present study, follistatin ( ) gene expression vectors with either a bicistronic gene transfer cassette alone, or a bicistron gene cassette carrying a matrix attachment region (MAR) were constructed and transfected to bovine fetal fibroblasts. Evaluations of both the integration and expression of exogenous indicated that the pMAR-CAG-FST-IRES-AcGFP1-polyA-MAR (pMAR-FST) vector had higher capacity to form monoclonal transgenic cells than the vector without MAR, though transient transfection and integration efficiency were similar with either construct. Remarkably, protein expression in transgenic cells with the pMAR-FST vector was significantly higher than that from the bicistronic vector. Exogenous was expressed in all of the pMAR-FST transgenic mice at F , F and F . Total muscle growth in F mice was significantly greater than in wild-type mice, with larger muscles in fore and hind limbs of transgenic mice. pMAR-FST transgenic mice were also found with more evenly distributed muscle bundles and thinner spaces between sarcolemma, which suggests a correlation between transgene expression-associated muscle development and the trend of muscle growth. In conclusion, a pMAR-FST vector, which excluded the resistant genes and frame structure, enhances and stabilizes gene expressions in both transfected cells and transgenic mice.

关键词： safety of transgenic     bicistron gene transfer body     transgenic mice     muscle development    

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Invading target cells: multifunctional polymer conjugates as therapeutic nucleic acid carriers

Ulrich L?CHELT, Ernst WAGNER

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 275-286 doi: 10.1007/s11705-011-1203-z

摘要： Polymer-based conjugates are an interesting option and challenge for the design of nano-sized drug-delivery systems, as they require advanced conjugation chemistry and precise engineering. In the case of nucleic acid therapy, non-viral carriers face several biological barriers during the delivery process, namely 1) protection of the cargo from extracellular degradation, 2) avoidance of non-specific interactions with non-targeted tissues, 3) efficient entry into the target cells, 4) intracellular trafficking to the site of action and 5) cargo release. To take on these obstacles, multifunctional conjugates can act as “smart polymers” with microenvironment-sensing dynamics to facilitate the separate delivery steps. Synthesis of defined polymer architectures with precise functionalization enables structure-activity relationships to be investigated and the integration of key functions for efficient delivery. Thus bioresponsive polymer conjugates, which are equipped with molecular devices responding to the certain microenvironments within the delivery pathway (e.g. pH, redox potential, enzymes) can be assembled. This review focuses on the modular engineering and conjugation of multifunctional polymeric structures for the utilization as “tailor-made” nucleic acid carriers.

关键词： conjugate     DNA     gene transfer     polymer     RNA     targeting    

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Numerical simulation of liquid falling film on horizontal circular tubes

Fengdan SUN, Songlin XU, Yongchuan GAO

《化学科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 322-328 doi: 10.1007/s11705-012-1296-z

摘要： The objective of this study is to investigate numerically the flow characteristics of falling film on horizontal circular tubes. Numerical simulations are performed using FLUENT for 2D configurations with one and two cylinders. The volume of fluid method is used to track the motion of liquid falling film and the gas-liquid interface. The effect of flow characteristics on heat and transfer coefficient may be remarkable, although it has been neglected in previous studies. The velocity distribution and the film thickness characteristics on the top tube, some special flow characteristics on the bottom tube, intertube flow modes and effect of liquid feeder height on flow characteristics have been studied. Our simulations indicate that 1) the velocity distributions of the upper and lower parts of the tube are not strictly symmetric and non-uniform, 2) the film thickness depends on flow rate and angular distributions, 3) the flow characteristics of the top tube are different from those of the bottom tube, 4) three principal and two intermediate transition modes are distinguished, and 5) the liquid feed height plays an important role on the formation of falling film. The numerical results are in a good agreement with the theoretical values by the Nusselt model and the reported results.

关键词： falling film     horizontal tube     flow characteristics     film thickness     liquid feeder height    

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Numerical analysis of bearing behaviors of single batter piles under horizontal loads in various directions

《结构与土木工程前沿（英文）》 2023年 第17卷 第2期   页码 224-237 doi: 10.1007/s11709-022-0914-1

摘要： The horizontal bearing behavior of a single batter pile (SBP) is vital to its application in practical engineering; however, the horizontal responses of SBPs change with the directions of horizontal loads, and this phenomenon is rarely investigated. Therefore, the directional differences in the horizontal bearing behaviors of SBPs are investigated in this study. Four model tests are conducted to preliminarily examine the effects of the skew angle of horizontal loads on the horizontal bearing capacities and distributions of the bending moments of the SBPs. Subsequently, the differences in the responses of the SBPs under horizontal loads in various directions at full scale are analyzed comprehensively via finite-element (FE) analysis. The effects of the skew angle on SBP-soil interaction are discussed. Moreover, an empirical design method is proposed based on the FE analysis results to predict the bearing ratios of SBPs in medium-dense and dense sand while considering the effects of the skew angle, batter angle, and pile diameter. The method is confirmed to be effective, as confirmed by the close agreement between the predicting results with the model test (reported in this study) and centrifuge model test results (reported in the literature).

关键词： single batter pile     skew horizontal load     model test     finite-element analysis     empirical design method    

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Experimental study on shear behavior of reinforced concrete beams with web horizontal reinforcement

Dong XU,Yu ZHAO,Chao LIU

《结构与土木工程前沿（英文）》 2014年 第8卷 第4期   页码 325-336 doi: 10.1007/s11709-014-0080-1

摘要： In determining the shear capacity of reinforced concrete beams, current codes do not provide any calculation method to evaluate the influence of web horizontal reinforcement, although they exist as structural reinforcements (or skin reinforcement). The present paper comprises results of 11 reinforced concrete beams in an effort to investigate the influence of web horizontal reinforcement on the shear behavior of reinforced concrete beams. The primary design variables are the shear-span-depth ratio, different reinforcement ratio of stirrups and web horizontal reinforcement. Influence of web horizontal reinforcement on crack patterns and failure mode was studied. It was found that web horizontal reinforcement can increase the shear capacity of the beams and restrain growth of inclined cracks effectively. Test results are very valuable, as very few references of shear tests can be found focusing on the effect of web horizontal reinforcement on the shear capacity of the beams.

关键词： reinforced concrete beam     shear strength     web horizontal reinforcement     experiments    

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标题 作者 时间 类型 操作

Bacteriophages in water pollution control: Advantages and limitations

期刊论文

Assessment of antibiotic resistance genes in dialysis water treatment processes

Xuan Zhu, Chengsong Ye, Yuxin Wang, Lihua Chen, Lin Feng

期刊论文

Natural convection heat transfer of water in a horizontal circular gap

SU Guanghui, WU Yingwei, Kenichiro Sugiyama

期刊论文

Convective mass transfer from a horizontal rotating cylinder in a slot air jet flow

Hongting MA , Dandan MA , Na YANG ,

期刊论文

Experimental study on heat transfer characteristics of supercritical carbon dioxide in horizontal tube

LV Jing, FU Meng, QIN Na, DONG Bin

期刊论文

Influences and mechanisms of nanofullerene on the horizontal transfer of plasmid-encoded antibiotic resistance

Qingkun Ji, Caihong Zhang, Dan Li

期刊论文

Experimental study on saturated flow boiling heat transfer of R290/R152a binary mixtures in a horizontal

Xin ZOU, Maoqiong GONG, Gaofei CHEN, Zhaohu SUN, Jianfeng WU

期刊论文

Construction of lentiviral vector carrying Rab9 gene and its expression in mouse brain

Youguo HAO, Min ZHANG, Jinzhi XU, Bitao BU, Jiajun WEI

期刊论文

Elimination of antibiotic resistance genes and control of horizontal transfer risk by UV-based treatment

Virender K. Sharma, Xin Yu, Thomas J. McDonald, Chetan Jinadatha, Dionysios D. Dionysiou, Mingbao Feng

期刊论文

Optimized human factor IX expression cassettes for hepatic-directed gene therapy of hemophilia B

null

期刊论文

Matrix attachment regions included in a bicistronic vector enhances and stabilizes follistatin gene expressions

Xiaoming HU,Jing GUO,Chunling BAI,Zhuying WEI,Li GAO,Tingmao HU,Shorgan BOU,Guangpeng LI

期刊论文

Invading target cells: multifunctional polymer conjugates as therapeutic nucleic acid carriers

Ulrich L?CHELT, Ernst WAGNER

期刊论文

Numerical simulation of liquid falling film on horizontal circular tubes

Fengdan SUN, Songlin XU, Yongchuan GAO

期刊论文

Numerical analysis of bearing behaviors of single batter piles under horizontal loads in various directions

期刊论文

Experimental study on shear behavior of reinforced concrete beams with web horizontal reinforcement

Dong XU,Yu ZHAO,Chao LIU

期刊论文