The effects of antioxidants, vitamins C and E, on sperm quality, testosterone levels, superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentration were studied in artesunate treated rats. 25 male rats (160 to 250 g) divided into five groups were used for the study. Group 1 animals received normal saline and served as control while groups 2 to 5 received artesunate in therapeutic doses of 2.9 mg/Kg body weight on day 1 and 1.45 mg/Kg body weight on days 2 to 5 orally. Following artesunate pretreatment, groups 3, 4 and 5 rats received vitamin C (100 mg/kg), vitamin E (100 mg/kg) and a combination of both respectively orally for the 5 days. There was no significant difference in sperm viability and motility in all groups while count significantly (p<0.05) increased in group 3 animals treated with vitamin C. Serum testosterone level was significantly increased (p< 0.05) in groups 4 and 5. The MDA concentrations were significantly increased (p < 0.05) while SOD activity concurrently decreased significantly (p<0.05) in groups 2, 3, and 5 indicating an oxidative-counter oxidative relationship. It was thus concluded that artesunate at therapeutic doses and duration had no significant effect on sperm quality and serum testosterone level in male rats while vitamin C, and combination of vitamins C and E tend to promote reproductive functions in artesunate-treated male rats.

This investigation is conducted to assess the influence of some heat treatment procedures on the structure and mechanical properties of cast ASTM A grade B-4 steel to which formation of grain boundary carbides have been a major problem. Some cast ASTM A grade B-4 steel samples were quench-hardened, martempered and tempered. The as-cast and heat-treated samples were thereafter tested for tensile strength, yield strength, impact strength, ductility and hardness. Some of the samples were also prepared for metallographic examination and their microstructures were studied. It was observed that in all cases, the microstructures were mainly austenite matrix with or without carbides at the grain boundaries and in the austenitic grains depending on the heattreatment adopted. The measured mechanical properties varied and were greatly dependent on the presence or absence of carbides either at the grain boundaries or at both the grain boundaries and in the grains of austenite matrix. Two of the heat treatment procedures were found to be appropriate as post-casting processes suitable for ASTM A 128 grade B-4 steel components designed to function under a condition in which impact strength and hardness are simultaneously required.

Since investments in R&D have been identified as a major engine of growth by the proponents of the endogenous growth models, many studies have investigated the determinants of R&D intensity. In this study, our primary objective is to establish, empirically, the determinants of inter-provincial R&D intensity in China over the period 2001 to 2010. We collected both crosssectional and time series data for 31 provinces, municipalities, and autonomous regions of China and the estimation of our model was done using the fixed effect model, random effect model, Difference GMM, and System GMM. Our findings reveal that factors such as economic development level, investment in science and technology, and human capital have a significant positive effect on R&D Intensity, but trade openness has a negative and significant impact on R&D intensity. Even though the fixed asset investment has a negative relationship with R&D intensity, it is not statistically significant.