Research on forming quality of poly-wedge pulley spinning

As an important power transmission part, pulleys are widely used in automobile industry, agricultural machinery, pumps and machines. A near-net forming process for six-wedge belt pulleys manufacturing was put forward. For this purpose, the required tooth shape and size can be formed directly by spinning without machining. The whole manufacturing procedures include blanking, drawing and spinning. The spinning procedure includes five processes, performing, drumming, thickening, toothing and finishing. The forming defects occurred during each forming processes of poly-wedge pulley spinning, such as the drumming failure, flanged opening-end, folded side-wall, insufficient bottom size, flashed opening-end, cutting-off bottom, are introduced, and the factors influencing the defects are analyzed. The corresponding preventive measures are put forward

Expression of Recombinant EARLI1, a Hybrid Proline-rich Protein of Arabidopsis, in \u3cem\u3eEscherichia coli\u3c/em\u3e and its Inhibition Effect to the Growth of Fungal Pathogens and \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e

EARLI1 is an Arabidopsis gene with pleiotropic effects previously shown to have auxiliary functions in protecting plants against freezing-induced cellular damage and promoting germinability under low-temperature and salinity stresses. Here we determined whether recombinant EARLI1 protein has anti-fungal activity. Recombinant EARLI1 protein lacking its signal peptide was produced in Escherichia coli BL21(DE3) using isopropyl β-d-1-thiogalactopyranoside (IPTG) induction and the prokaryotic expression vector pET28a. Expression of EARLI1 was analyzed by Western blotting and the protein was purified using affinity chromatography. Recombinant EARLI1 protein was applied to fungal cultures of Saccharomyces cerevisiae, Botrytis cinerea and Fusarium oxysporum, and membrane permeability was determined using SYTOX green. Full-length EARLI1 was expressed in S. cerevisiae from the GAL1 promoter using 2% galactose and yeast cell viability was compared to control cells. Our results indicated that application of recombinant EARLI1 protein to B. cinerea and F. oxysporum could inhibit the growth of the necrotrophic fungi. Besides, addition of the recombinant protein to liquid cultures of S. cerevisiae significantly suppressed yeast growth and cell viability by increasing membrane permeability, and in vivo expression of the secreted form of EARLI1 in S. cerevisiae also had a remarkable inhibition effect on the growth of yeast cells

Spatial-Temporal Instability of an Inviscid Shear Layer

In this work, we explore the transition of absolute instability and convective instability in a compressible inviscid shear layer, through a linear spatial-temporal instability analysis. From linearized governing equations of the shear layer and the ideal-gas equation of state, the dispersion relation for the pressure perturbation was obtained. The eigenvalue problem for the evolution of two-dimensional perturbation was solved by means of shooting method. The zero group velocity is obtained by a saddle point method. The absolute/convective instability characteristics of the flow are determined by the temporal growth rate at the saddle point. The absolute/convective nature of the flow instability has strong dependence on the values of the temperature ratio, the velocity ratio, the oblique angle, and M number. A parametric study indicates that, for a great value of velocity ratio, the inviscid shear layer can transit to absolute instability. The increase of temperature ratio decreases the absolute growth rate when the temperature ratio is large; the effect of temperature ratio is opposite when the temperature ratio is relatively small. The obliquity of the perturbations would cause the increase of the absolute growth rate. The effect of M number is different when the oblique angle is great and small. Besides, the absolute instability boundary is found in the velocity ratio, temperature ratio, and M number space

Spatial-Temporal Instability of an Inviscid Shear Layer

In this work, we explore the transition of absolute instability and convective instability in a compressible inviscid shear layer, through a linear spatial-temporal instability analysis. From linearized governing equations of the shear layer and the ideal-gas equation of state, the dispersion relation for the pressure perturbation was obtained. The eigenvalue problem for the evolution of twodimensional perturbation was solved by means of shooting method. The zero group velocity is obtained by a saddle point method. The absolute/convective instability characteristics of the flow are determined by the temporal growth rate at the saddle point. The absolute/convective nature of the flow instability has strong dependence on the values of the temperature ratio, the velocity ratio, the oblique angle, and number. A parametric study indicates that, for a great value of velocity ratio, the inviscid shear layer can transit to absolute instability. The increase of temperature ratio decreases the absolute growth rate when the temperature ratio is large; the effect of temperature ratio is opposite when the temperature ratio is relatively small. The obliquity of the perturbations would cause the increase of the absolute growth rate. The effect of number is different when the oblique angle is great and small. Besides, the absolute instability boundary is found in the velocity ratio, temperature ratio, and number space

Inhibitory Effects of Arabidopsis \u3cem\u3eEARLI1\u3c/em\u3e Against \u3cem\u3eBotrytis cinerea\u3c/em\u3e and \u3cem\u3eBradysia difformis\u3c/em\u3e

The aim of this study is to understand the function of EARLI1 in plants subjected to different biotic stresses using EARLI1 overexpressing (OX) and T-DNA knockout (KO) transgenic Arabidopsis lines. Higher levels of expression of EARLI1 in OX lines were confirmed by RT-PCR and Northern blot analysis. The full-length EARLI1 mRNA could not be detected by RT-PCR in KO lines, while only a shorter transcript could be found by RNA gel blotting. In wild-type Col-0 plants (Wt), EARLI1 could be induced by Botrytis cinerea and H2O2, indicating this gene might be involved in plant defense system against pathogens. Trypan blue staining of the infected leaves showed that overexpression of EARLI1 could inhibit the growth of B. cinerea and disruption of EARLI1 in KO lines led to vigorous propagation of the necrotrophic fungus. In addition, KO plants were attacked earlier and more frequently than the wild-type Col-0 plants by fungus gnat (Bradysia difformis). In vivo expression in Saccharomyces cerevisiae demonstrated that the secreted form of EARLI1 could suppress the cell viability by increasing the permeability of the plasma membrane. As a protein localized to cell wall, EARLI1 might play as a component of a receptor and function in resistant response of plants to biotic stresses by sensing environment changes and delivering the signals to intracellular regulation network

Association of basal serum testosterone levels with ovarian response and in vitro fertilization outcome

<p>Abstract</p> <p>Background</p> <p>To evaluate basal testosterone (T) levels during follicular phase of the menstrual cycle as a predictor for ovarian response and in vitro fertilization (IVF) outcome.</p> <p>Method</p> <p>We analyzed data retrospectively from hospital-based IVF center including one thousand two hundred and sixty Chinese Han women under their first IVF cycle reached the ovum pick-up stage, without polycystic ovary syndrome (PCOS) or endometriosis undergoing long IVF protocol. Patients were divided into 2 groups. Group 1: patients with diminished ovarian reserve (basal FSH >10 IU/L) (n = 187); Group 2: patients with normal ovarian reserve (basal FSH < = 10 IU/L) (n = 1073). We studied the association of basal T levels with ovarian response and IVF outcome in the two groups. Long luteal down-regulation protocol was used in all patients, that is, the gonadotropin releasing hormone agonist was administered in the midluteal phase of the previous cycle and use of recombinant FSH was started when satisfactory pituitary desensitization was achieved.</p> <p>Results</p> <p>Basal T levels were markly different between pregnant and non-pregnant women in Group 1; whereas not in Group 2. A testosterone level of 47.85 ng/dl was shown to predict pregnancy outcome with a sensitivity of 52.8% and specificity of 65.3%; and the basal T was correlated with the numbers of large follicles (> 14 mm) on HCG day in Group 1. Significantly negative correlations were observed between basal T, days of stimulation and total dose of gonadotropins after adjusting for confounding factors in both groups.</p> <p>Conclusion</p> <p>In women with diminished ovarian reserve, basal T level was a predictor for the number of large follicles on HCG day and pregnancy outcome; but could not in those with normal serum FSH. Basal T levels were associated with both days of stimulation and total dose of gonadotropins, indicating that lower level of T might relate with potential ovarian poor response.</p