Cylinder-like in-situ AI/24Si FGMs were produced by using electromagnetic separating process. Si primary phase reinforced layer with volume fraction as high as 16 pct was formed at the outer region of the cylinder-lik...Cylinder-like in-situ AI/24Si FGMs were produced by using electromagnetic separating process. Si primary phase reinforced layer with volume fraction as high as 16 pct was formed at the outer region of the cylinder-like samples where the local hardness and wear resistance were enhanced remarkably. Moreover, both of strength and ductility in the inner region provided insurance of reliable strength for this as-cast gradient material. It indicated that general mechanical properties such as good wear resistance at the outer region and good ductility in the central part could be obtained with the optimized redistribution of the Si primary particles under the electromagnetic force.展开更多
AIM:This paper aims to develop a data-based semi-quantitative food frequency questionnaire (SQFFQ) covering both urban and rural areas in the Chaoshan region of Guangdong Province, China, for the investigation of rela...AIM:This paper aims to develop a data-based semi-quantitative food frequency questionnaire (SQFFQ) covering both urban and rural areas in the Chaoshan region of Guangdong Province, China, for the investigation of relationships between food intake and lifestyle-related diseases among middle-aged Chinese. METHODS: We recruited 417 subjects from the general population and performed an assessment of the diet, using a 3-d weighed dietary record survey. We employed contribution analysis (CA) and multiple regression analysis (MRA) to select food items covering up to a 90% contribution and a 0.90 R2, respectively. The total number of food items consumed was 523 (443 in the urban and 417 in the rural population) and the intake of 29 nutrients was calculated according to the actual consumption by foods/ recipes. RESULTS: The CA selected 233,194, and 183 foods/recipes for the combined, the urban and the rural areas, respectively, and then 196,157, and 160 were chosen by the MRA. Finally, 125 foods/recipes were selected for the final questionnaire. The frequencies were classified into eight categories and standard portion sizes were also calculated. CONCLUSION: For adoption of the area-specific SQFFQ, validity and reproducibility tests are now planned tc determine how the combined SQFFQ performs in actual assessment of disease risk and benefit.展开更多
Objective: To determine the concentration of malondialdehyde (MDA), product of lipid peroxidation, in seminal plasma and evalu ate its significance. Methods: Ninety-three cases of infertile pa tients were divided into...Objective: To determine the concentration of malondialdehyde (MDA), product of lipid peroxidation, in seminal plasma and evalu ate its significance. Methods: Ninety-three cases of infertile pa tients were divided into the obstructive azoospermic (12 cases), the non-obstructive azoospermic (15 cases), the oligozoospermic (21 cases), the asthenozoospermic (19 cases), the oligoastheno zoospermic (16 cases) and the oligoasthenoteratozoospermic (10) groups. Eighteen fertile males served as the controls. MDA con centration was assessed by high-performance liquid chromatogra phy (HPLC). Results: With the exception of the obstructive azoospermic group, the MDA concentration in the seminal plasma was significantly different between the control group and the infer tile groups (P<0.01) as well as between the different infertile groups. Conclusion: Determination of MDA concentration in the seminal plasma is helpful to the diagnosis of male infertility induced by overproduction of reactive oxygen species.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 59871029)the National Key Research Foundation of China (Grant No. G1999064900-4).
文摘Cylinder-like in-situ AI/24Si FGMs were produced by using electromagnetic separating process. Si primary phase reinforced layer with volume fraction as high as 16 pct was formed at the outer region of the cylinder-like samples where the local hardness and wear resistance were enhanced remarkably. Moreover, both of strength and ductility in the inner region provided insurance of reliable strength for this as-cast gradient material. It indicated that general mechanical properties such as good wear resistance at the outer region and good ductility in the central part could be obtained with the optimized redistribution of the Si primary particles under the electromagnetic force.
基金Supported by the Science and Technology Project Foundation of Guangdong Province, No. 2003C33706Grant-in-Aid for Scientific Research on Priority Areas (C) from the Ministry of Education, Science, Sports, Culture and Technology, Japan
文摘AIM:This paper aims to develop a data-based semi-quantitative food frequency questionnaire (SQFFQ) covering both urban and rural areas in the Chaoshan region of Guangdong Province, China, for the investigation of relationships between food intake and lifestyle-related diseases among middle-aged Chinese. METHODS: We recruited 417 subjects from the general population and performed an assessment of the diet, using a 3-d weighed dietary record survey. We employed contribution analysis (CA) and multiple regression analysis (MRA) to select food items covering up to a 90% contribution and a 0.90 R2, respectively. The total number of food items consumed was 523 (443 in the urban and 417 in the rural population) and the intake of 29 nutrients was calculated according to the actual consumption by foods/ recipes. RESULTS: The CA selected 233,194, and 183 foods/recipes for the combined, the urban and the rural areas, respectively, and then 196,157, and 160 were chosen by the MRA. Finally, 125 foods/recipes were selected for the final questionnaire. The frequencies were classified into eight categories and standard portion sizes were also calculated. CONCLUSION: For adoption of the area-specific SQFFQ, validity and reproducibility tests are now planned tc determine how the combined SQFFQ performs in actual assessment of disease risk and benefit.
文摘Objective: To determine the concentration of malondialdehyde (MDA), product of lipid peroxidation, in seminal plasma and evalu ate its significance. Methods: Ninety-three cases of infertile pa tients were divided into the obstructive azoospermic (12 cases), the non-obstructive azoospermic (15 cases), the oligozoospermic (21 cases), the asthenozoospermic (19 cases), the oligoastheno zoospermic (16 cases) and the oligoasthenoteratozoospermic (10) groups. Eighteen fertile males served as the controls. MDA con centration was assessed by high-performance liquid chromatogra phy (HPLC). Results: With the exception of the obstructive azoospermic group, the MDA concentration in the seminal plasma was significantly different between the control group and the infer tile groups (P<0.01) as well as between the different infertile groups. Conclusion: Determination of MDA concentration in the seminal plasma is helpful to the diagnosis of male infertility induced by overproduction of reactive oxygen species.
