No abstract

The magnesium and magnesium alloys has applied widely in different industrial aspects in Vietnam in the modern life. Especially, the products from magnesium alloys implementing in the automotive have increased rapidly since the car elements tend to be generated by the light alloys in order to save the fuel. However, in the current time, Vietnam has no factories to produce the magnesium to adapt the domestic demand although it owns an enrich resource of raw materials. This research indicates the possibility of using the dolomite ore in Thanhhoa – Vietnam to make the magnesium as well as evaluate the primary factors like recovering temperature, reducing agent rate, recovering time having effect on the reduction efficiency of Thanhhoa dolomite by metallothermic method in vacuum (Pidgeon Process). This is basic process, low investment and suitable for the small and medium scales in Vietnam. The experiment includes heating, indicating the chemical ingredients and recovering experiment on the dolomite after calcination (dolime) by using ferrosilicon. The thermodynamic model is created to estimate the recovering efficiency in the Pidgeon. The result shows that the CaO/MgO molar ratio of calcination dolomite in Thanhhoa is nearly 1.5 which is suitable to produce magnesium in the case of highly-required efficiency and pureness. Besides, the result from the furnace of the experiment is lower than the one in the model. The samples are set up to check the influence of the rate of ferrosilicon in the compound. The result indicates that the ideal efficiency reaches 85 % with 30 % ferrosilicon. Moreover, the study confirms that the optimal operating conditions in this process are recovering during three hours at 1200 °C and 100 Pa pressure. This result proves the potential application of Thanhhoa dolomite in the industry suitable with the current condition in Vietnam

Purpose: The aim of this study was to investigate the prevalence and risk factors of erectile dysfunction (ED) in men of infertile couples from an in vitro fertility center in the northern Vietnam. Methods: A total of 138 men of infertility couples were enrolled in this study from January to May, 2018. The International Index of Erectile Function questionnaire scale was used to access the severity of ED and several related factors were also collected to determine risk factors. Results: The prevalence of ED among men of infertile couples was 18.1%, including 13 mild ED (9.4%), 7 mild to moderate ED (5.1%), 2 moderate ED (1.4%) and 1 severe ED (0.7%). Using logistic regression analysis, we showed that risk factors associated ED were smoking above 5 pack/years with OR = 3.16, CI = 0.98 – 10.18, p = 0.05; not graduating junior high school, OR = 5.11, CI = 1.11 – 23.8, p = 0.03, and azoospermia, OR = 7.55 , CI = 2.18 – 26.16, p = 0.001. We observed relatively high OR in men with smoking under 5 pack/years (OR = 2.51), abnormal semen analysis (hypospermia, oligozoospermia, asthenozoospermia, or teratozoospermia) (OR=2.36), but there was not significant differences compared with reference group. Conclusion: The prevalence of ED among men of infertile couples in this study was higher than infrtile men. Low level of education, smoking in a long period, and azoospermia were the main risk factors of ED in men. Further large-scale studies are needed to extend the results.

Background: Erectile dysfunction (ED) and infertility are important health concerns with negative impacts on the quality of life and couple’s relationship, which is emerging as an early marker for decreased general health. Objectives: This pilot study intended to investigate the prevalence and risk factors of erectile dysfunction in men of infertile couples referred to an in vitro fertility center in northern Vietnam. Methods: A total of 138 men of infertile couples were enrolled in this study from January to May 2018. The International Index of Erectile Function questionnaire scale was used to evaluate the severity of ED. Also, several related factors were collected to determine potential risk factors. Results: The prevalence of ED among was 18.1%, including 13 mild ED (9.4%), 7 mild to moderate ED (5.1%), 2 moderate ED (1.4%), and 1 severe ED (0.7%). The logistic regression analysis showed that risk factors associated ED were smoking > 5 pack/years (OR = 3.16, CI = 0.98 - 10.18; P = 0.05), not graduating from junior high school (OR = 5.11; CI = 1.11 - 23.8; P = 0.03) and azoospermia (OR = 7.55; CI = 2.18 - 26.16; P = 0.001). We observed relatively high OR in men with smoking < 5 pack/years (OR = 2.51) and abnormal semen analysis (hypospermia, oligozoospermia, asthenozoospermia, or teratozoospermia) (OR = 2.36), but there was no significant difference compared to the reference group. Conclusions: In the present study, the prevalence of ED among men of infertile couples was higher than infertile men. Low level of education, smoking for a long period, and azoospermia were the main risk factors of ED in men. Further large-scale studies are needed to extend the results.