Effects of Methotrexate on Plasma Cytokines and Cardiac Remodeling and Function in Postmyocarditis Rats

Excessive immune activation and inflammatory mediators may play a critical role in the pathogenesis of chronic heart failure. Methotrexate is a commonly used anti-inflammatory and immunosuppressive drug. In this study, we used a rat model of cardiac myosin-induced experimental autoimmune myocarditis to investigate the effects of low-dose methotrexate (0.1 mg/kg/d for 30 d) on the plasma level of cytokines and cardiac remodeling and function. Our study showed that levels of tumor necrosis factor-(TNF-)alpha and interleukin-6 (IL-6) are significantly increased in postmyocarditis rats, compared with the control rats. Methotrexate treatment reduced the plasma levels of TNF-alpha and IL-6 and increased IL-10 level, compared to saline treatment. In addition, postmyocarditis rats showed significant cardiac fibrosis characterized by increased myocardial collagen volume fraction, perivascular collagen area, and the ratio of collagen type I to type III, compared with the control rats. However, MTX treatment not only markedly attenuated cardiac fibrosis, diminished the left ventricular end-diastolic dimension, but also increased the left ventricular ejection fraction and fractional shortening. Collectively, these results suggest that low-dose methotrexate has ability to regulate inflammatory responses and improves cardiac function and hence contributes to prevent the development of postmyocarditis dilated cardiomyopathy

Study of the Microstructure, Mechanical, and Magnetic Properties of LaFe11.6Si1.4Hy/Bi Magnetocaloric Composites

We have successfully synthesized LaFe11.6Si1.4Hy/Bi composites by cold pressing together with vacuum annealing technology, and systematically investigated the microstructure, magnetism, mechanical performance, and magnetocaloric properties. LaFe11.6Si1.4Hy particles are well surrounded by metallic Bi, without the formation of new phase. The maximum values of the volumetric magnetic entropy change -ΔSM are as high as 51, 49, and 35 mJ/cm3K around 263 K, for the composites with 5, 10 and 15 wt % Bi contents, respectively. The maximum value of the compressive strength for LaFe11.6Si1.4Hy/Bi composites increased continuously from 155 to 358 MPa with increasing Bi content, from 0 to 15 wt %

Performance Enhancement in Borocarburized Low-Carbon Steel by Double Glow Plasma Surface Alloying

In this paper, the performance of low-carbon steel is enhanced after introducing a borocarburized diffusion layer via double glow plasma surface alloying technology. Due to the boron-carbon gradient structure of low-carbon steel, the protective coating exhibits an excellent wear and corrosion resistance. Interestingly, the borocarburized layer consists of a 64 μm carburized layer and a 27 μm boride layer, which plays an effective role in enhancing the microhardness of borocarburized low-carbon steel, exhibiting a 1440 Vickers hardness increase in the surface microhardness of low-carbon steel. The potentiodynamic polarization measurement and impedance measurement results indicate that the boride protective film can effectively prevent aggressive chloride ions from invading the substrate, which indicates an excellent property of corrosion resistance. This systematic study paves a promising way for the future application of hard coatings in severe environments