http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Dan-dan Sun,Xu Gu,Jun-guo Li,Ting Yao,Ying-chao Dong 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.5
The objective of this study was to evaluate the quality of five commercial enzyme linked immunosorbent assay (ELISA) kits (A, B, C, D, and E) from different suppliers for detecting aflatoxin B1 (AFB1). AFB1-free corn samples supplemented with different levels of AFB1 (5, 10, and 20 μg/kg) were used as positive controls and 6 replicates of each control sample were tested to evaluate the accuracy and precision of these kits. In addition, we also evaluated the performance of these ELISA kits for AFB1 in 30 feed samples, including corn, distillers dried grains with soluble, wheat samples, soybean meal, and poultry feed, which were verified by high performance liquid chromatography. Results showed that the coefficients of variation ranged from 1.18% to 16.22% in intra-plate and 2.85% to 18.04% in inter-plate for the determination of AFB1. The half maximal inhibitory concentration for five kits ranged from 3.72 to 7.22 μg/kg. The quantitation limits of AFB1 were all under the legal limit in China but somewhat inconsistent with kit instructions. Although the recovery rate of four of the five kits were either less than 90% or more than 110%, all these values were acceptable in practice. Two kits had high false positive rates (C and E). In conclusion, our results revealed that the qualities of five tested ELISA kits were significantly different.
Three degrees of freedom chatter stability prediction in the milling process
Dan Gu,Yuan Wei,Bin Xiong,Shulin Liu,Dongfang Zhao,Baoqiang Wang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.9
Chatter in the cutting process has a great influence on workpiece surface quality, machining efficiency, and service life of the machine tool. This work presents three degrees of freedom (DOF) dynamic model applied to tool chatter for thin-walled structures in milling. Combined with dynamic cutting force modelling in the radial, axial and tangential directions, the stability chart was solved by adopting an improved semi-discretization method in time domain. And the stability prediction model considering regenerative effect was validated by cutting tests with specific axial depth of cut and spindle speed. The cutting experimental results performed at different axial depth of cuts were in accordance with predicted stability lobe diagram (SLD). Moreover, the effects of cutting contact angle and radial immersion ratio on SLD were also analyzed. The study results show that the dynamic model could make a good prediction of chatter stability, and the established approach is high efficient in predicting the chatter stability lobe considering the actual situation.
Sun, Dan-Dan,Gu, Xu,Li, Jun-Guo,Yao, Ting,Dong, Ying-Chao Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.5
The objective of this study was to evaluate the quality of five commercial enzyme linked immunosorbent assay (ELISA) kits (A, B, C, D, and E) from different suppliers for detecting aflatoxin $B_1$ ($AFB_1$). $AFB_1$-free corn samples supplemented with different levels of $AFB_1$ (5, 10, and $20{\mu}g/kg$) were used as positive controls and 6 replicates of each control sample were tested to evaluate the accuracy and precision of these kits. In addition, we also evaluated the performance of these ELISA kits for $AFB_1$ in 30 feed samples, including corn, distillers dried grains with soluble, wheat samples, soybean meal, and poultry feed, which were verified by high performance liquid chromatography. Results showed that the coefficients of variation ranged from 1.18% to 16.22% in intra-plate and 2.85% to 18.04% in inter-plate for the determination of $AFB_1$. The half maximal inhibitory concentration for five kits ranged from 3.72 to $7.22{\mu}g/kg$. The quantitation limits of $AFB_1$ were all under the legal limit in China but somewhat inconsistent with kit instructions. Although the recovery rate of four of the five kits were either less than 90% or more than 110%, all these values were acceptable in practice. Two kits had high false positive rates (C and E). In conclusion, our results revealed that the qualities of five tested ELISA kits were significantly different.
Comparative Study of the marR Genes within the Family Enterobacteriaceae
Dan Wang,Changjiang Guo,Longjiang Gu,Xiaohui Zhang 한국미생물학회 2014 The journal of microbiology Vol.52 No.6
marR genes are members of an ancient family originallyidentified in Escherichia coli. This family is widely distributedin archaea and bacteria. Homologues of this family have aconserved winged helix fold. MarR proteins are involved innon-specific resistance systems conferring resistance to multipleantibiotics. Extensive studies have shown the importanceof MarR proteins in physiology and pathogenicity inEnterobacteria, but little is known about their origin or evolution. In this study, all the marR genes in 43 enterobacterialgenomes representing 14 genera were identified, and the phylogeneticrelationships and genetic parameters were analyzed. Several major findings were made. Three conserved marRgenes originated earlier than Enterobacteriaceae and a genelossevent was found to have taken place in Yersinia pestisAntiqua. Three functional genes, rovA, hor, and slyA, werefound to be clear orthologs among Enterobacteriaceae. Thecopy number of marR genes in Enterobacteriaceae was foundto vary from 2 to 11. These marR genes exhibited a faster rateof nucleotide substitution than housekeeping genes did. Specifically, the regions of marR domain were found to besubject to strong purifying selection. The phylogenetic relationshipand genetic parameter analyses were consistentwith conservation and specificity of marR genes. These dualcharacters helped MarR to maintain a conserved bindingmotif and variable C-terminus, which are important to adaptiveresponses to a number of external stimuli in Enterobacteriaceae.
Polyamide Coated Soft Magnetic Microspheres and Their Magnetorheology
In Gu Kim,Ji Eun Kim,Ying Dan Liu,Hyoung Jin Choi IEEE 2012 IEEE transactions on magnetics Vol.48 No.11
<P>Magnetorheological (MR) fluid, which is composed of soft magnetic particles with little hysteresis dispersed in a non-magnetic liquid medium, is a phase controllable material under an external magnetic field. Magnetic microspheres consisting of a polyamide 6 (PA6) shell wrapping a magnetic carbonyl iron (CI) particle as a core were prepared using an in-situ polymerization method and adopted as a MR material to enhance the dispersion stability and mechanical properties. The physical characteristics of PA6 magnetic microspheres, such as morphology, magnetic properties, components of magnetic microspheres, and rheological properties, were investigated. The MR characteristics were measured using rotational and oscillatory tests. The sedimentation rate of the pure CI and PA6/CI suspension were also investigated.</P>
Fan Wei,Gu Peng,Pu Bin,Yue Dan,Xin Qiao,Zheng XiaoHui,Zeng ZhanPeng,Fan Shaoyong 한국유전학회 2023 Genes & Genomics Vol.45 No.8
Background Observational studies have shown that the age of menarche is associated with sarcopenia, but confounding factors make the causal relationship difficult to infer. Objective Therefore, we conducted a bidirectional two-sample Mendelian randomized (MR) analysis to evaluate the potential causal relationship between age at menarche and sarcopenia-related traits (hand grip strength, lean mass, walking pace). Methods We obtained the latest aggregate statistics from the Genome-wide association studies (GWAS) database on the age of menarche of 182,416 participants from ReproGen, the appendicular lean mass of 244,730 participants from EMBL’s European Bioinformatics Institute, the left-hand grip strength of 401,026 participants, the right-hand grip strength of 461,089 participants and the usual walking pace of 459,915 participants from the UK Biobank. The inverse variance weighting (IVW) method and other MR methods were used to evaluate the bidirectional causal relationship between the age of menarche and sarcopenia. Results The forward MR results showed that the age of menarche predicted by the gene was positively correlated with left-hand grip strength (IVWβ=0.041, P = 2.00 × 10−10), right-hand grip strength (IVWβ=0.053, P = 1.97 × 10−18), appendicular lean mass (IVWβ=0.012, P = 4.38 × 10−13) and usual walking pace (IVWβ=0.033, P = 1.62 × 10−8).In the reverse MR analysis, we also found that the usual walking pace was positively correlated with the age of menarche predicted by genes (IVWβ=0.532, P = 1.65 × 10−4). Still, there was no causal relationship between grip strength and appendicular lean mass and the age at menarche. Conclusion Our results show that earlier menarche will increase the risk of sarcopenia. In addition, people with higher muscle function tend to have menarche later. These findings may provide a reference for prevention strategies and interventions for menarche in advance and sarcopenia.