39 research outputs found
Genetic analysis of baculovirus resistance in lepidopteran model insect Bombyx mori L.
In order to clarify the resistant mechanism of BmNPV in silkworm, and from negative to prove agricultural pest inheritance of virus resistance, in this study, we used the highly resistant strain NB and susceptible strain 306 as the material through the method of classical genetics experiment, and proved that the baculovirus resistance in silkworm is controlled by a pair of autosomal dominant major gene. At the same time, we used random amplification of polymorphic DNA (RAPD) random primers to screen a molecular marker which are in high linkage with the resistant trait. Validity of the molecular marker was proved in BC1, F2 populations, which further demonstrated that the baculovirus resistance in silkworm is controlled by a pair of autosomal dominant major gene. This can provide an effective research basis for the emergence of baculovirus resistance in pest and its resistant mechanism.Key words: Bombyx mori, molecular markers, genetic analysis, biological control, baculovirus resistance
Preliminarily Static Analysis of CFETR Central Solenoid Magnet System
Conceptual design of China Fusion Engineering Test Reactor (CFETR) Central Solenoid (CS) coil had been started in Institute of Plasma Physics, Chinese Academy of Sciences. The highest field of CS coil is 17.2 T when the running current is 60 kA. CS magnet system mainly consists of 8 Nb3Sn coils compressed with 8 sets of preload structure. The functions of the preload structure are to apply an enough axial compression to the CS coils and to have a mechanical rigidity against the repulsive force between 8 Nb3Sn coils. This paper describes structural design of CFETR CS magnet system. A global finite element model is created based on the design geometry data to investigate the mechanical property of CFETR CS preload structure and support structure under the different operating conditions. 2D finite element model under electromagnetic is created to calculate the stress on the conductor jacket and turn insulation.</p
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Research on coal pillar width and control of gob side entry with fully-mechanized caving mining in extra thick coal seam
In order to study the reasonable width of coal pillar in gob side entry of fully mechanized top coal caving in extra thick coal seam, the 8305 working face is taken as the research object, and the method of theoretical analysis, numerical simulation and field practice is adopted. The reasonable width of coal pillar is 5.4-9.9 m by the internal and external stress field theory, limit equilibrium theory and the support conditions of coal pillar side in gob side entry. The reasonable width of coal pillar is determined to be 6 m by the distribution law of horizontal zero displacement surface and vertical stress peak value with the numerical simulation, and the targeted surrounding rock control technology is proposed. The practice shows that the displacement of roof and floor, the deformation of coal rib and coal pillar are small, and the surrounding rock control effect is well
Takagi–Sugeno Fuzzy Model-Based Control for Semi-Active Cab Suspension Equipped with an Electromagnetic Damper and an Air Spring
Variable damping shock absorbers have received extensive attention for their efficient vibration reduction performance, and air springs have also been widely used in high-end commercial vehicles due to their nonlinear stiffness characteristics. This paper presents a novel semi-active cab suspension integrated with an air spring and a variable damping electromagnetic damper (A-EMD). The electromagnetic damper (EMD) prototype was designed, manufactured and tested. Then, due to the interference of nonlinear stiffness characteristics of the air spring with the controller in the subsequent design, the Takagi–Sugeno fuzzy method was adopted to segmentally linearize its nonlinearity, based on which an H∞ state feedback semi-active controller was designed to control the EMD to generate variable damping force. Furthermore, a Luenberger state observer was designed to provide immeasurable state parameters for the controller. Numerical simulations were carried out to validate the effectiveness of the proposed approaches, and the results show that the proposed control strategy can significantly improve the ride comfort of the A-EMD system. The vibration dose value (VDV) acceleration under the bump road and the frequency-weighted acceleration root mean square (FWA-RMS) under the random road decreased by 36.05% and 19.77%, respectively, compared with the passive suspension system
Takagi–Sugeno Fuzzy Model-Based Control for Semi-Active Cab Suspension Equipped with an Electromagnetic Damper and an Air Spring
Variable damping shock absorbers have received extensive attention for their efficient vibration reduction performance, and air springs have also been widely used in high-end commercial vehicles due to their nonlinear stiffness characteristics. This paper presents a novel semi-active cab suspension integrated with an air spring and a variable damping electromagnetic damper (A-EMD). The electromagnetic damper (EMD) prototype was designed, manufactured and tested. Then, due to the interference of nonlinear stiffness characteristics of the air spring with the controller in the subsequent design, the Takagi–Sugeno fuzzy method was adopted to segmentally linearize its nonlinearity, based on which an H∞ state feedback semi-active controller was designed to control the EMD to generate variable damping force. Furthermore, a Luenberger state observer was designed to provide immeasurable state parameters for the controller. Numerical simulations were carried out to validate the effectiveness of the proposed approaches, and the results show that the proposed control strategy can significantly improve the ride comfort of the A-EMD system. The vibration dose value (VDV) acceleration under the bump road and the frequency-weighted acceleration root mean square (FWA-RMS) under the random road decreased by 36.05% and 19.77%, respectively, compared with the passive suspension system
Design Analysis and Experimental Study of Robotic Chair for Proton Heavy Ion Radiotherapy
Proton heavy ion radiotherapy is widely used and currently represents the most advanced radiotherapy technology. However, at present, proton heavy ion radiotherapy chairs in fixed beam radiotherapy rooms do not have a head and neck positioning function. This paper presents a novel design for a proton heavy ion radiotherapy chair with a head and neck positioning device. The design of the posture adjustment mechanism and the head and neck positioning device of the treatment chair is based on U-TRIZ theory and ergonomics, respectively. A positive kinematic analysis of the posture adjusting mechanism was carried out, as well as a workspace analysis of the head and neck positioning device. Finally, positioning error experiment and ergonomic evaluation were performed on a prototype of the head and neck positioning device. The proposed design of the treatment chair satisfies the requirements for posture adjustment and achieves the head and neck positioning function. The experimental results also provide a basis for further optimization of the design
Effect of Microbial Inoculation on Carbon Preservation during Goat Manure Aerobic Composting
Carbon is the crucial source of energy during aerobic composting. There are few studies that explore carbon preservation by inoculation with microbial agents during goat manure composting. Hence, this study inoculated three proportions of microbial agents to investigate the preservation of carbon during goat manure composting. The microbial inoculums were composed of Bacillus subtilis, Bacillus licheniformis, Trichoderma viride, Aspergillus niger, and yeast, and the proportions were B1 treatment (1:1:1:1:2), B2 treatment (2:2:1:1:2), and B3 treatment (3:3:1:1:2). The results showed that the contents of total organic carbon were enriched by 12.21%, 4.87%, and 1.90% in B1 treatment, B2 treatment, and B3 treatment, respectively. The total organic carbon contents of B1 treatment, B2 treatment, and B3 treatment were 402.00 ± 2.65, 366.33 ± 1.53, and 378.33 ± 2.08 g/kg, respectively. B1 treatment significantly increased the content of total organic carbon compared with the other two treatments (p < 0.05). Moreover, the ratio of 1:1:1:1:2 significantly reduced the moisture content, pH value, EC value, hemicellulose, and lignin contents (p < 0.05), and significantly increased the GI value and the content of humic acid carbon (p < 0.05). Consequently, the preservation of carbon might be a result not only of the enrichment of the humic acid carbon and the decomposition of hemicellulose and lignin, but also the increased OTU amount and Lactobacillus abundance. This result provided a ratio of microbial agents to preserve the carbon during goat manure aerobic composting
Identification of an immune‐related gene signature as a prognostic target and the immune microenvironment for adrenocortical carcinoma
Abstract Background Adrenocortical carcinoma (ACC) is a rare endocrine malignancy. Even with complete tumor resection and adjuvant therapies, the prognosis of patients with ACC remains unsatisfactory. In the microtumor environment, the impact of a disordered immune system and abnormal immune responses is enormous. To improve treatment, novel prognostic predictors and treatment targets for ACC need to be identified. Hence, credible prognostic biomarkers of immune‐associated genes (IRGs) should be explored and developed. Material and methods We downloaded RNA‐sequencing data and clinical data from The Cancer Genome Atlas (TCGA) data set, Genotype‐Tissue Expression data set, and Gene Expression Omnibus data set. Gene set enrichment analysis (GSEA) was applied to reveal the potential functions of differentially expressed genes. Results GSEA indicated an association between ACC and immune‐related functions. We obtained 332 IRGs and constructed a prognostic signature on the strength of 3 IRGs (INHBA, HELLS, and HDAC4) in the training cohort. The high‐risk group had significantly poorer overall survival than the low‐risk group (p < .001). Multivariate Cox regression was performed with the signature as an independent prognostic indicator for ACC. The testing cohort and the entire TCGA ACC cohort were utilized to validate these findings. Moreover, external validation was conducted in the GSE10927 and GSE19750 cohorts. The tumor‐infiltrating immune cells analysis indicated that the quantity of T cells, natural killer cells, macrophage cells, myeloid dendritic cells, and mast cells in the immune microenvironment differed between the low‐risk and high‐risk groups. Conclusion Our three‐IRG prognostic signature and the three IRGs can be used as prognostic indicators and potential immunotherapeutic targets for ACC. Inhibitors of the three novel IRGs might activate immune cells and play a synergistic role in combination therapy with immunotherapy for ACC in the future