What Affect Lower Grade Learner’s Perceived Usefulness and Perceived Ease of Use of Mobile Digital Textbook Learning System? An Empirical Factor Analyses Investigation in China

Haijiao Shen,Liming Luo,Zhong Sun 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.1

Although perceived usefulness and perceived ease of use are two important factors which could directly influence the acceptance of technology and actual usage for digital textbook, less attention has been paid to children’s mobile digital textbook usage. Therefore, the purpose of this study is to investigate and empirically validate the perceived usefulness and the perceived ease of use by elementary school students during their usage of digital textbook. For data analyses, two questionnaires were developed using existing scales from prior TAM instruments. The sample of this study included 5,245 elementary school students in China who have experience of using digital textbook. The results indicate that students believe that using mobile digital textbook enhance their study performance, but they believe it is not very easy to use. Besides, gender, grade and parents’ attitudes towards mobile digital textbook affect the usage. Gender differences exist only in the perceived ease of use. Male students make less effort in using mobile digital textbook than female students. In addition, the students in lower grades tend to have more positive perspectives on mobile digital textbook than the students in higher grades. Furthermore, mobile digital textbook usage experience (time & frequency) has a significant effect on the students’ perceived usefulness. Finally, parents’ attitudes towards mobile digital textbook influence their children’s perceived usefulness.

Yeast Surface Display of Capsid Protein VP7 of Grass Carp Reovirus: Fundamental Investigation for the Development of Vaccine Against Hemorrhagic Disease

( Shaoxiang Luo ),( Liming Yan ),( Xiaohua Zhang ),( Li Yuan ),( Qin Fang ),( Yong An Zhang ),( Heping Dai ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.12

VP7, an outer capsid protein of grass carp reovirus (GCRV), was expressed and displayed on the surface of Saccharomyces cerevisiae for developing an efficient vaccine against hemorrhagic disease of grass carp. The result of flow cytometry analysis indicated that protein VP7 could be displayed on the surface of yeast cells after inducing with galactose. The expression of VP7 was confirmed by western blot analysis and further visualized with confocal microscopy. The specific antibodies against VP7 generated from mice were detectable from all immune groups except the control group, which was immunized with untransformed yeast cells. The displaying VP7 on glycosylation-deficient strain EBYΔMnn9 was detected to induce a relatively low level of specific antibody amongst the three strains. However, the antiserum of EBYΔM9-VP7 showed relative high capacity to neutralize GCRV. Further neutralization testing assays indicated that the neutralizing ability of antiserum of the EBYΔM9-VP7 group appeared concentration dependent, and could be up to 66.7% when the antiserum was diluted to 1:50. This result indicates that appropriate gene modification of glycosylation in a yeast strain has essential effect on the immunogenicity of a yeast-based vaccine.

Model test and numerical simulation on the bearing mechanism of tunnel-type anchorage

Li, Yujie,Luo, Rong,Zhang, Qihua,Xiao, Guoqiang,Zhou, Liming,Zhang, Yuting Techno-Press 2017 Geomechanics & engineering Vol.12 No.1

The bearing mechanism of tunnel-type anchorage (TTA) for suspension bridges is studied. Model tests are conducted using different shapes of plug bodies, which are circular column shape and circular truncated cone shape. The results show that the plug body of the latter shape possesses much larger bearing capacity, namely 4.48 times at elastic deformation stage and 4.54 times at failure stage compared to the former shape. Numerical simulation is then conducted to understand the mechanical and structural responses of plug body and surrounding rock mass. The mechanical parameters of the surrounding rock mass are firstly back-analyzed based on the monitoring data. The calculation laws of deformation and equivalent plastic strain show that the numerical simulation results are rational and provide subsequent mechanism analysis with an established basis. Afterwards, the bearing mechanism of TTA is studied. It is concluded that the plug body of circular truncated cone shape is able to take advantage of the material strength of the surrounding rock mass, which greatly enhances its bearing capacity. The ultimate bearing capacity of TTA, therefore, is concluded to be determined by the material strength of surrounding rock mass. Finally, recommendations for TTA design are proposed and discussed.

Enhancement of Pyruvate Productivity in Candida glabrata by Deleting the CgADE13 Gene to Improve Acid Tolerance

Xiulai Chen,Qiuling Luo,Jia Liu,Liming Liu 한국생물공학회 2018 Biotechnology and Bioprocess Engineering Vol.23 No.5

Acid tolerance is one of the critical factors to evaluate the quality of the industrial production strains, especially organic acid producing microorganisms. To circumvent this problem, we investigated the physiological function of adenylosuccinate lyase in AMP metabolism from Candida glabrata by deleting the corresponding gene, CgADE13. At pH 4.0, CgADE13 deletion resulted in a 68.3% and 112.0% increase in biomass and cell viability compared to those of wild type strain (wt), respectively. In addition, CgADE13 deletion also protected cell morphology and counteracted ROS production. Further, the intracellular ATP level of strain Cgade13Δ was decreased by 25.0%, and its H+-ATPase activity was increased by 15.0%. Finally, pyruvate production with strain Cgade13Δ in a 30-L batch bioreactor at pH 4.0 reached 53.9 g/L, and pyruvate productivity was increased by 166.7% compared to that of wt. This is the first report regarding tolerance engineering of C. glabrata for enhancing pyruvate productivity, which provides a good starting point for metabolic engineering to achieve the industrial production of other chemicals.

Effect of D-(+)-Glucose on the Stability of Polyvinyl Alcohol Fricke Hydrogel Three-Dimensional Dosimeter for Radiotherapy

Yuejiao Yang,Jie Chen,Liming Yang,Bin Chen,Zhenmei Sheng,Wenyun Luo,Guoping Sui,Xun Lu,Jianxin Chen 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.3

D-(+)-glucose (Glc) was added to the original Fricke polyvinyl alcoholeglutaraldehydeexylenol orange (FPGX) hydrogel dosimeter system to make a more stable FPGX hydrogelthree-dimensional dosimeter in this paper. Polyvinyl alcohol was used as a substrate,which was combined with Fricke solution. Various concentrations of Glc were tested withlinear relevant fitting for optimal hydrogel production conditions. The effects of variousformulations on the stability and sensitivity of dosimeters were evaluated. The resultsindicated that D-(+)-Glc, as a free radical scavenger, had a great effect on stabilizing thedose response related to absorbency and reducing the auto-oxidization of ferrous ions. Acareful doping with Glc could slow down the color change of the dosimeter before and afterradiation without any effect on the sensitivity of the dosimeter.

The Effects of Physicochemical Factors and Cell Density on Nitrite Transformation in a Lipid-Rich Chlorella

( Fang Liang ),( Kui Du ),( Xiaobin Wen ),( Liming Luo ),( Yahong Geng ),( Yeguang Li ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.12

To understand the effects of physicochemical factors on nitrite transformation by microalgae, a lipid-rich Chlorella with high nitrite tolerance was cultured with 8 mmol/l sodium nitrite as sole nitrogen source under different conditions. The results showed that nitrite transformation was mainly dependent on the metabolic activities of algal cells rather than oxidation of nitrite by dissolved oxygen. Light intensity, temperature, pH, NaHCO3 concentrations, and initial cell densities had significant effects on the rate of nitrite transformation. Single-factor experiments revealed that the optimum conditions for nitrite transformation were light intensity: 300 μmol/㎡/s; temperature: 30℃; pH: 7-8; NaHCO3 concentration: 2.0 g/l; and initial cell density: 0.15 g/l; and the highest nitrite transformation rate of 1.36 mmol/l/d was achieved. There was a positive correlation between nitrite transformation rate and the growth of Chlorella. The relationship between nitrite transformation rate (mg/l/d) and biomass productivity (g/l/d) could be described by the regression equation y = 61.3x (R(2) = 0.9665), meaning that 61.3 mg N element was assimilated by 1.0 g dry biomass on average, which indicated that the nitrite transformation is a process of consuming nitrite as nitrogen source by Chlorella. The results demonstrated that the Chlorella suspension was able to assimilate nitrite efficiently, which implied the feasibility of using flue gas for mass production of Chlorella without preliminary removal of NOX.