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The proppant equilibrium height is the basis of investigating proppant distributions in artificial fractures and has a great significant influence on hydraulic fracturing effect. There are two shortcomings of current research on proppant equilibrium heights, one of which is that the effect of fracture widths is neglected when calculating the settling velocity and another of which is that the settling bed height is a constant when building the settling bed height growth rate model. To fill those two shortcomings, this work provides a novel model for the proppant equilibrium height in hydraulic fractures for slickwater treatments. A comparison between the results obtained from the novel model and the published model and experimental results indicates that the proposed model is verified. From the sensitivity analysis, it is concluded that the proppant equilibrium height increases with an increasing proppant density. The proppant equilibrium height decreases with an increase in the slickwater injection rate and increases with an increase in the proppant injection rate. The increase in proppant diameter results in an increasing the friction factor, which makes proppant equilibrium heights decrease. Meanwhile, the increase in proppant sizes results in an increase in proppant settling rates, which makes the proppant equilibrium height increase. When the effect of the proppant diameter on settling rates is more significant than that on friction factors, the equilibrium height increases with an increasing proppant size. This work provides a research basis of proppant distributions during the hydraulic fracture.

A highly enantio- and regio-selective Markovnikov hydromonofluoro(methyl)alkylation of 1,3-dienes was developed using redox-neutral nickel catalysis. It provided a facile strategy to construct diverse monofluoromethyl- or monofluoroalkyl-containing chiral allylic molecules. Notably, this represents the first catalytic asymmetric Markovnikov hydrofluoroalkylation of olefins. The practicability of this methodology is further highlighted by its broad substrate scope, mild base-free conditions, excellent enantio- and regio-selectivity, and diversified product elaborations to access useful fluorinated building blocks.

If the tigernut meal left after oil extraction is used as a material for starch resources instead of being wasted, the industrial value of tigernut would be improved. Thus, we investigated the effect of extrusion before oil extraction on the yield, structure and function of starches within tigernut meals (TMS). Compared with the yield of native starch, the yield of TMS-130-11 (barrel temperature: 130 °C; feed moisture: 11 %) was increased by 1.97 %, and that of TMS-140-11 (barrel temperature: 140 °C; feed moisture: 11 %) was decreased by 7.82 %. The starches cannot be obtained when the barrel temperature is above 140 °C with 11 % feed moisture. Extrusion slightly decreased the relative crystallinity and increased the ratio of B2-chains in amylopectin. These changes resulted in reductions in peak viscosity while improving the elastic properties of the starch gel. These results will provide useful information regarding the use of starch isolated from tigernut meal.

The A-type Aurora kinase is upregulated in many human cancers, and it stabilizes MYC-family oncoproteins, which have long been considered an undruggable target. Here, we describe the design and synthesis of a series of pyrimidine-based derivatives able to inhibit Aurora A kinase activity and reduce levels of cMYC and MYCN. Through structure-based drug design of a small molecule that induces the DFG-out conformation of Aurora A kinase, lead compound 13 was identified, which potently (IC50 < 200 nM) inhibited the proliferation of high-MYC expressing small-cell lung cancer (SCLC) cell lines. Pharmacokinetic optimization of 13 by prodrug strategies resulted in orally bioavailable 25, which demonstrated an 8-fold higher oral AUC (F = 62.3%). Pharmacodynamic studies of 25 showed it to effectively reduce cMYC protein levels, leading to >80% tumor regression of NCI-H446 SCLC xenograft tumors in mice. These results support the potential of 25 for the treatment of MYC-amplified cancers including SCLC.

Cannabinoid receptor 1 (CB1) is a G protein-coupled receptor and a therapeutic target for metabolic disorders. Numerous CB1 antagonists have been developed, but their functional selectivities and bias towards G protein or β-arrestin signaling have not been systemically characterized. In this study, we analyzed the binding affinities and downstream signaling of two series of pyrazole derivatives bearing 1-aminopiperidine (Series I) or 4-aminothiomorpholine 1,1-dioxide (Series II) moieties, as well as the well-known CB1 antagonists rimonabant and taranabant. Analyses of the results for the Series I and II derivatives showed that minor structure modifications to their functional groups and especially the incorporation of 1-aminopiperidine or 4-aminothiomorpholine 1,1-dioxide motifs can profoundly affect their bias toward G protein or β-arrestin signaling, and that their binding affinity and functional activity can be disassociated. Docking and molecular dynamics simulations revealed that the binding modes of Series I and II antagonists differed primarily in that Series I antagonists formed an additional hydrogen bond with the receptor, whereas those in Series II formed a water bridge.

Objective: To explore how miR-146a-3p can regulate the cytokine secretion of endothelial cells in atherosclerotic mice through the nuclear factor κB subunit (RELB). Methods: Apolipoprotein knockout (ApoE-/-) mouse atherosclerosis model was established by feeding program of high-fat diet formula and vascular endothelial cells were performed on primary culture. The difference in expression levels of miR-146a-3p in endothelial tissues of atherosclerotic mice and control mice was detected by real-time fluorescence quantitative PCR. The match between mir-146a-3p and RelB was analyzed by TargetScanHuman. Then whether miR-146a-3p targeted RELB was checked by luciferase reporter system. In the case of miR- 146a-3p mimics overexpression or miR-146a-3p inhibitor knockdown, the granulocyte colony stimulating factor (GCSF), the levels of granulocyte macrophage colony stimulating factor (GM-CSF), interleukin 2 (IL-2), interleukin 3 (IL-3), interleukin 4 (IL-4), interleukin 5 (IL-5), interleukin 6 (IL-6), interleukin 9 (IL-9), interleukin 10 (IL-10), interleukin 12 p40 (IL-12 p40), interleukin 12 p70 (IL-12 p70), interleukin 13 (IL-13), interleukin 17 (IL-17), interferon gamma (IFN-γ) , monocyte chemotactic protein 1 (MCP-1), monocyte chemoattractant protein 5 (MCP-5), small inducible cytokine A5 (RANTES), and tumor necrosis factor-α (TNFα) were detected by enzyme-linked immunosorbent assay. Results: Compared with the control group, the expression of miR-146a-3p in vascular endothelial tissue of atherosclerotic mice was reduced (P

Small cell lung cancer (SCLC) accounts for approximately 15% of all lung cancers, leading to ~30,000 deaths each year in the United States. SCLC patients often present with metastasis at time of diagnosis, excluding surgery as a treatment option. While patients show high response rate to standard chemotherapy such as cisplatin/etoposide, they soon develop drug resistance and disease progression. Therefore, new therapeutic strategies are urgently needed for SCLC. BPR6K609S0 is a novel Aurora kinase inhibitor which has been designed to inhibit the kinase activity of Aurora A, and induces proteasome-mediated degradation of MYC. The BPR6K609S0 active molecule provokes cell apoptosis and inhibits proliferation of several SCLC cell lines with IC50 < 100 nM. Oral administration of BPR6K609 induces >60 % tumor regression in a NCI-H446 xenograft mouse model. In addition, BPR6K609 further reduces tumor progression in NCI-H446 xenograft mice pre-treated with LY3295668, an Aurora A-selective inhibitor which is currently under clinical investigation. These results support the clinical potential of BRP6K609S0 for the treatment of SCLC. Citation Format: Ya-Hui Chi, Chun-Ping Chang, Yi-Yu Ke, Wen-Hsing Lin, Wan-Ping Wang, Chia-Hua Tsai, Yen-Ting Chen, Yu-Jie Su, Ming-Chun Hung, Zhong-Wei Wu, Mine-Hsine Wu, Teng-Kuang Yeh, Ching-Ping Chen, Jen-Shin Song, Chiung-Tong Chen, Chuan Shih. BPR6K609: An Aurora kinase inhibitor targeting small cell lung cancer with MYC amplification [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1937.

In view of the present situation that the recovery of waste thermosetting plastics and products is difficult and the utilization rate is low, regeneration mechanism, regeneration methods and recycling process of waste thermosetting plastics under mechanical thermal coupling fields are proposed. Regeneration powders of Thermosetting Phenolic plastic are obtained by mechanochemical activated regeneration methods, the molecular structure, properties and crosslink density of phenol regeneration materials are analyzed. Analysis results show that network crosslinked molecular structure was destroyed, reactive groups produced and the crosslink density decreased. The activity of regeneration powders was reinforced and its plasticity was also improving, so the utilization rate was improved. Regeneration composite plastics were manufactured by hot press molding or extrusion compression molding. The microstructure of regeneration composite plastics was analyzed, and its mechanical strength was tested. Results showed that the tensile strength and bending strength of samples (weight ratio ≥ 50%) respectively exceed 15.88 MPa and 33.49 MPa. At last process parameters for regeneration effects were discussed, and these parameters were optimized. When particle size was 80 mesh (size ≤ 0.18 mm), quality proportion was 50~70%, pressure was 10Mpa, heating temperature was 180~190°C, the optimal effects for regenerated composite were achieved.

The phenomena of cooperation in animal and human society are ubiquitous, but the selfish outcome that no player contributes to the public good will lead to the "tragedy of the commons". The recent research shows that high punishment can improve the cooperation of the population. In this paper, we introduce a punishment mechanism into spatial voluntary public goods games with every individual only knowing his own payoff in each round. Using the self-adjusting rules, we find that the different cost for punishment can lead to different effects on the voluntary public goods games. Especially, when the cost for punishment is decreased, a higher contribution region will appear in the case of low r value. It means even for the low r value, individuals can form the contributing groups in large quantities to produce a more efficient outcome than that in moderate r value. In addition, we also find the players' memory can have effects on the average outcome of the population.

According to domestic and international history of foam glass, the foam glass development situation of the United States, France, Japan, the former Soviet Union and China was specifically introduced. Moreover ,the foam-glass-production-lines history was divided by generations and the production-lines characteristics each generation was presented in detail. Compared with the production scale ,investments and unit production cost of foam glass production line on different generations ,we could find that building high-generation production lines, increasing productivity, improving quality, reducing costs and enhancing competitiveness will be the development trend of foam glass industry in the future.

Poyang Lake is under the potential threaten from water eutrophication. The implementation of pollution-purifying agricultural industrialization in the Poyang Lake area is an important strategy for controlling the non-point source pollution and achieving economic transformation in the area. In this article, the characteristics of pollution-purifying agriculture and the advantages for its industrialization in the Poyang Lake is discussed. The suitable patterns for the implementation of purifying-agricultural industrialization in Poyang Lake are also proposed.

Small cell lung cancer (SCLC) is one the most aggressive tumors with poor survival rate. SCLC patients often present with metastasis at time of diagnosis, excluding surgery as a treatment option. While patients show high response rate to standard chemotherapy such as cisplatin/etoposide, they soon develop drug resistance and disease progression. Therefore, new therapeutic strategies are urgently needed for SCLC. Several characteristics of SCLC such as aggressiveness and drug resistance could attribute to the existence of a cancer stem cell (CSC) subpopulation in SCLC. The SCLC cell line NCI-H446 has been shown to present high degree of stemness and express stem cell markers including CD133, OCT4, MYC and Nestin. Here we develop a pyrimidine-based small molecule BPR6K471 which potently inhibits Aurora kinase activities in enzymatic- and cell- based assays. BPR6K471 efficiently (IC50 = 66 nM) inhibits proliferation of NCI-H446, and reduces the expression of stem-cell markers. In addition, intravenous injection of BPR6K471 inhibits >90 % progression of NCI-H446 in a mouse xenograft model. These results suggest that targeting Aurora kinases may be a potential therapeutic strategy to combat the CSC subpopulation in SCLC. Citation Format: Chun-Ping Chang, Yi-Yu Ke, Wen-Hsing Lin, Dai-Hui Jhuo, Wan-Ping Wang, Chia-Hua Tsai, Yen-Ting Chen, Yu-Jie Su, Ming-Chun Hung, Zhong-Wei Wu, Po-Chu Kuo, Teng-Kuang Yeh, Ching-Ping Chen, Jen-Shin Song, Chiun-Tong Chen, Chuan Shih, Ya-Hui Chi. An Aurora kinase inhibitor BPR6K471 inhibits tumor growth and reduces the cancer stem cell-like properties of small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3851.

Design for energy optimization is an efficiency way to improve energy utilization rate and the environmental performance of products. A new design method for energy optimization based on energy unit (EU) is put forward. The method integrates energy property into design process of product, and takes the product as a set of design units and realizes the design for energy optimization process by the design of EU. Based on the introduction of the concept EU, the design for energy optimization process in the utilization stage is analyzed. At last, a product case is given to show the design process.

The water quality monitoring revealed that the water quality in Poyang Lake is increasely degenerating in the past several years and the deterioration reasons were analyzed. The increasingly serious water pollution indicated that there were inherent drawbacks in current environmental management system of China. Therefore, the typical models of water pollution prevention and control in developed countries and China were researched. The explorations of water pollution prevention and control based on ecosystem management for Poyang Lake were reviewed, especially the practice of Mountain-River-Lake (MRL) Program in Poyang Lake Basin. At last, the challenges of water pollution prevention and control in Poyang Lake Basin was put forword such as law and policy, organization structure, participation mechanism. The researches indicated that the multiplicity and complexity of nature, humanities, society and economy in Poyang Lake determined its importance and necessity to implement ecosystem-based water environment management. In the future construction of water pollution prevention model based on integrated ecosystem management is an inevitable trend for Poyang Lake basin.

Various mechanical forces are used to promote the waste thermosetting phenol resin to produce the physical decomposition process. The molecular structure and physicochemical properties change, thus it obtains the reversible thermos plasticity and restore the processing performance. The paper proposes the regeneration principle based on physical methods, and smashing and regeneration experiments have been carried out. The optimized design for important factors of rotational speed, crushing time, feed, feed size and other parameters which impact crushing and regenerating effects has been carried out after experiments. Multivariate quadratic simulation equations are established and the order of significantly affecting the regeneration is determined.

Based on software GaBi4.3, life cycle assessment method is used to analyze the abiotic depletion, energy consumption and environmental emissions of recycling process of 1kg waste thermosetting phenolic laminated plastic. This paper also takes advantage of CML2001 provided by GaBi to assess the environmental impacts through the recycling process. The result shows that the rank of environmental impact is: Regeneration> Molding > Crush; the main environmental impacts are global warming potential, acidification potential and eutrophication potential.

Through the combined mechanical forces of sheer, friction and squeezing, the rigid polyurethane powder particles get certain plasticity. Based on the principles of mechanical and physical methods, an orthogonal test is designed, and then characterization analysis under conditions of different parameters is carried out through ATR-FTIR. The test indicates that when the rotate speed is 2400r/min, test time is 120min and inlet amount is 24g, the carbamic acid ester groups break down at the place of C-O bond and the cross-linked network structure is destroyed, then the best degradation effect is gained. This article provides theoretical basis for the recycle of thermosetting plastic.

The Naming Game (NG) describes the emergence of conventions and shared lexicons in a population of agents interacting in a pairwise fashion. In this work, we introduce a new yet simple speakers’ rule into a minimal Naming Game where the speaker is more likely to choose the successful word in her earlier history and to convey it to the hearer. We find that the convergence time decreases with the increasing weight of successful words, which indicates that preferential selection of successful words may accelerate the reaching of consensus.

Propose a recycling technology of waste thermosetting phenolic resin based on mechanical and physical method,use the range and variance analysis of orthogonal test of four factors at three different levels, obtain the affection of speed ,time, feeding material weight ,feeding particle size on degradation efficiency of thermosetting phenolic resin. According to the affection ,the influencing factors could be arranged as follows : speed>feeding particle size> time>feeding material weight,and optimal technology parameters are determined as follows: speed is 3000 r / min, time is 90 min, feeding material weight is 50 g, feeding particle size is 0.425 mm.

Pulverizing the waste thermosetting phenol-formaldehyde resins by the self-developed machine which is used to recycle thermosetting plastics, studying the variable laws of fractions of different particle changing with the pulverization time, and establishing a pulverizing dynamic model by regression analysis. The results show that the particle distribution parameters b and m are not constants but the functions of pulverization time; the established equation of regression dynamic is high accurate which clearly describes the pulverization process.

Using adjustable speed crushing regeneration test device for the recovery experiment of thermosetting phenolic plastic waste, this paper analyses the principle of recovery process. Through particle size analytical technique, FTIR, XRD and SEM etc. various testing method is analyzed mechanochemical effects of crushing process. Research the speed, time, temperature process parameters of the influence of recycling process conditions. According to the experimental results, it established the mechanochemical model and analyzed the degradation and regeneration mechanism of thermosetting phenolic plastic waste.

PPO was a better intensifier and charred material for High-impact polystyrene (HIPS), it could make HIPS achieve UL94V-0 with APP, MC, RDP. Especially, RDP not only improved the flame-retarded property but also controlled the hole producing, and had the best consistent with matrix which could improve the mechanical properties. SBS and SEBS were better consistent with matrix, especially SEBS was tiny granule, which could be dispersed in matrix easily. The properties of SEBS toughened the non-halogen flame-retarded HIPS was followed: tensile strength: 18.83MPa; izod notch impact strength: 15.7kJ/m2; UL94V-0.

In this study, we analyze element geochemistry of submarine basalt in situ, which is sampled in hydrothermal areas from ultraslow spreading Southwest Indian Ridge, including the fresh basalt rocks (B19-9, B15-13) and altered basalt (B5-2). And we can confirm that altered mineral in B5-2 is celadonite by microscope and Raman Spectrum. Furthermore, amygdaloidal celadonites are analyzed by electron microprobe (EPMA) and EDS-line scanning. The results show that K-contents decrease and Na-contents increase from the core to the edge in these altered minerals, indicating the transition from celadonite to saponite. Celadonite is an altered minerals, forming in low temperature (50 degrees C) and oxidizing condition, while saponite form in low water/rock and more reducing condition. As a result, the transition from celadonite to saponite suggests environment change from oxidizing to reducing condition. Using the result of EPMA as internal standard, we can analyze rare earth elements (REE) in altered mineral in situ. Most of result show positive Eu anomaly (Δ(Eu)), indicating hydrothermal fluid transform from oxidizing to reducing, and reducing fluid rework on the early altered minerals. Comparison with REE in matrix feldspar both in altered and unaltered zoning, we find that reducing fluid can leach REE from the matrix feldspar, leading to lower total REE concentrations and positive Eu anomaly. So leaching process play an important role in hydrothermal system.

In the present study, content and occurrence of Au, Ag in three submarine hydrothermal sulfide samples from the ultra-slow-spreading Southwest Indian Ridge (SWIR) were studied by using inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of ICP-AES show that all of the samples have signs of Au-Ag enrichment. By SEM/EDS, we discovered a mass of gold-silver minerals in the samples. In S27-4, gold occurs as irregular-shaped native gold and electrum grains in sulfides or between crystal particles. However, we discovered lots of Au-independent silver minerals except parts of electrum in S35-22. EDS results of silver minerals indicate that silver minerals closely related with halogen element, inferring that silver minerals may be silver halides. Electrum in S35-22 can be absorbed at the surface or crystal edge of pyrite besides occurring in or between sulfides as S27-4, supposed to be related to surface defect in pyrite. Electrum is the only Au-Ag mineral discovered in S35-17. These electrum gains occur as inclusion gold, absorbed gold or fissure gold. In addition, there are different Au-Ag mole ratios of electrum in three samples, indicating distinct hydrothermal conditions. In the base of research before, we consider that AgCl2(-) is the dominant complex of silver in ore-forming fluid of S27-4, however, gold is transported as AuCl2(-) transforming to AuHS(0), indicating that hydrothermal fluids decreased from high-moderate to moderate-low temperature and conductive cooling played an important role in this process. Similar enrichment mechanism happened in S35-22, but silver halides discovered in S35-22 suggest a higher temperature and chloride in the early stage. However, The enrichment of electrums in black smoke sample (S35-17) relates to mixing of hydrothermal fluids and seawater.

To evaluate the value of the Centerpiece plate in the cervical single open-door laminoplasty and compared its advantages with conventional suture fixation methods.From December 2009 to August 2011,32 patients with cervical spondylotic myelopathy were treated with operation. Of them, 15 cases underwent cervical single open-door laminoplasty and Centerpiece plate fixation (group A),there were 8 males and 7 females,aged from 51 to 65 years old with an average of 60.5 years and ranged in course of disease from 2 to 15 months; 17 cases underwent cervical single open-door laminoplasty and silk suture fixation (group B), there were 9 males and 8 females, aged from 49 to 66 years old with an average of 61.5 years and ranged in course of disease from 1 to 14 months. All the patients with unsteady gait symptom before operation and cervical MR imaging showed spinal cord compression and denaturation. According to standard of Japanese Orthopaedics Association (JOA) to evaluate the spinal nervers function before operation and at 6 months after operation;according to CT scan to determine the sagittal diameter (AP) of upper vertebral canal and cervical activity (ROM).All the patients were followed up from 8 to 20 months with an average of 13 months. All the incisions healed well and no complications such as internal fixation loosening and breakage,spinal cord injury, reclose-door were found. Postoperative symptoms relieved obviously and MRI and CT showed vertebral canal volume expanded significantly. Operative time and blood loss in group A were respectively (155.0+/-12.3) min, (407.0+/-11.8) ml and in group B were respectively (148.0+/-14.4) min, (398.0+/-15.4) ml. There was no significantly differenc, between two groups (P0.05). JOA score in group A improved from preoperative 9.1+/-2.6 to postoperative 15.5+/-1.8 and in group B improved from preoperative 9.3 +/- 2.1 to postoperative 13.1 +/- 2.5 (P0.05). CT sagittal diameter (AP) in group A increased from preoperative (10.7+/-2.4) mm to postoperative (17.6+/-3.2) mm and in group B increased from preoperative (11.6+/-1.7) mm to postoperative (15.9+/-2.0) mm (P0.05). Cervical activity (ROM) in group A be- fore and after operation were respectively (51.0+/-2.6) degrees, (45.0+/-3.5) degrees and in group B were respectively (52.0+/-1.8) and (42.0+/-2.4). There was no significantly difference before operation between two groups (P0.05) and there was significantly difference after operation between two groups (P0.05).Treatment of cervical spondylotic myelopathy with posterior single open-door laminoplasty and Centerpiece plate fixation can enlarge spinal canal volume,keep original cervical activity, improve postoperative JOA score. The method has obviously advantages compared with traditional suture fixation methods.

Waste thermosetting plastics are considered to be a difficulty of recycling of polymeric materials due to its three-dimensional reticular cross-linkage structure and the complexity of the types of materials. Take the hard thermosetting polyurethane plastic which is widely used in the market as the research object and deferent from the traditional methods, this paper puts forward waste thermosetting plastics recycling process based on mechanical and physical methods. Through strong shear, extrusion, grinding and other mechanical forces combined with the frictional heat generated, not only the physical properties and morphology of the material change, but also the molecular structure and chemical properties of the material change and produce degradation. The paper has analyzed the degradation mechanism of polyurethane and influencing factors based on mechanical and physical methods. At last the reasonable parameters of effective degradation are obtained, which are combined with the actual experimental results.

The present paper describes the use of optical waveguide lightmode spectroscopy (OWLS) for study of the binding interaction of the vascular endothelial growth factor (VGEF) with VEGF receptor 2 (VEGFR2). VEGF were immobilized in the surface of an 3-amino 3-propyltriethoxy silane (APTES) modified sensor chip. The solutions with different concentration of VEGFR2 were injected to the system to investigate the kinetic character with OWLS on the solid and liquid interface. The receptor binding and dissociation on the interface, quantified by association and dissociation rate coefficients ka and kd, were determined by the OWLS experiments. The k(a) and k(d) is 6.86 x 10(5) L x mol(-1) x s(-1) and 1.15 x 10(-3) s(-1), respectively. The results show that OWLS method could meet the requirement of kinetic determination of ligand--receptor interaction in applications for related fundamental research and pharmaceutical development.

Listeria monocytogenes (LM) is a food-borne pathogen inducing listeriosis, an illness characterized by encephalitis, septicaemia, and meningitis. Listeriolysin O (LLO) is absolutely required for virulence by L. monocytogenes, and is found only in virulent strains of the species. One of the best ways to detect and confirm the pathogen is detection of one of the virulence factors, LLO, produced by the microorganism. This paper focused on the electrical method used to detect the LLO toxin gene in food products and organism without labeling the target DNA. The electrochemical sensor was obtained by immobilizing single-stranded oligonucleotides onto the gold electrode with the mercaptan activated by N-hydroxysulfosuccinimide (NHS) and N-(3-dimethylamion)propyl-N'-ethyl carbodiimidehydrochloride (EDC). The hy-bridization reaction that occurred on the electrode surface was evidenced by Cyclic Voltammetry (CV) analysis using [Co(phen)3](ClO4)3 as an indicator. The covalently immobilized single-stranded DNA could selectively hybridize to its complementary DNA in solution to form double-stranded DNA on the gold surface. A significant increase of the peak cur-rent of Cyclic Voltammetry (CV) upon hybridization of immobilized ssDNA with PCR amplification products in the solu-tion was observed. This peak current change was used to monitor the amount of PCR amplification products. Factors deter-mining the sensitivity of the electrochemical assay, such as DNA target concentration and hybridization conditions, were investigated. The coupling of DNA to the electrochemical sensors has the potential of the quantitative evaluation of gene.