The very low cut-off value for sperm morphology of 4% morphologically normal spermatozoa, as proposed in the new edition of the World Health Organization （WHO） manual on semen analysis, is in agreement with recently...The very low cut-off value for sperm morphology of 4% morphologically normal spermatozoa, as proposed in the new edition of the World Health Organization （WHO） manual on semen analysis, is in agreement with recently published values and reflects the trend of a decline in reported mean values for normal sperm morphology. The reduced value for morphologically normal spermatozoa over the years may be due to several factors. The first is the introduction of strict criteria for the evaluation of sperm morphology. Other reasons may include the introduction of additional criteria for sperm morphology abnormalities and the suggested decrease in semen parameters because of increasing negative environmental influences. Although on its own the newly proposed very low normal value may not provide the strong predictive value for a males＇ fertility potential, as originally reported for sperm morphology evaluated according to strict criteria, a good predictive value can still be obtained if the holistic, strict approach for sperm morphology evaluation is followed together with additional sperm morphology parameters now available, because certain morphology patterns and sperm abnormalities are now known to be of strong prognostic value. In addition, better international standardization of the technical methodology, consensus on the interpretation of sperm morphology evaluation criteria and standardized international external quality control （EQC） schemes, are of utmost importance to maintain the good predictive value of sperm morphology.展开更多
Excessive use of agro-chemicals （such as mineral fertilizers） poses potential risks to soil quality. Application of organic amendments and reduction of inorganic fertilizer are economically feasible and environmenta...Excessive use of agro-chemicals （such as mineral fertilizers） poses potential risks to soil quality. Application of organic amendments and reduction of inorganic fertilizer are economically feasible and environmentally sound approaches to de- velop sustainable agriculture. This study investigated and evaluated the effects of mineral fertilizer reduction and partial substitution of organic amendment on soil fertility and heavy metal content in a 10-season continually planted vegetable field during 2009-2012. The experiment included four treatments： 100% chemical fertilizer （CF100）, 80% chemical fertilizer （CF80）, 60% chemical fertilizer and 20% organic fertilizer （CF60＋OM20）, and 40% chemical fertilizer and 40% organic fertilizer （CF40＋OM40）. Soil nutrients, enzyme activity and heavy metal content were determined. The results showed that single chemical fertilizer reduction （CF80） had no significant effect on soil organic matter content, soil catalase activity and soil heavy metal content, but slightly reduced soil available N, P, K, and soil urease activity, and significantly reduced soil acid phosphatase activity. Compared with CF100, 40 or 60% reduction of chemical fertilizer supplemented with organic fertilizer （CF60＋OM20, CF40＋OM40） significantly increased soil organic matter, soil catalase activity and urease activity especially in last several seasons, but reduced soil available P, K, and soil acid phosphatase activity. In addition, continu- ous application of organic fertilizer resulted in higher accumulation of Zn, Cd, and Cr in soil in the late stage of experiment, which may induce adverse effects on soil health and food safety.展开更多
Aim: To investigate a simple method for assaying acrosin activity for the evaluation of male fertility. Methods:The acrosin activity of 7.5 × 10~6 sperm without seminal plasma and acrosin activity inhibitors was ...Aim: To investigate a simple method for assaying acrosin activity for the evaluation of male fertility. Methods:The acrosin activity of 7.5 × 10~6 sperm without seminal plasma and acrosin activity inhibitors was assayed using N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA) and detergent (Triton X-100) as substrate. Results: The acrosin ac-tivity of 60 normal fertile men (35 ± 10 μIU/10~6 sperm ) was higher than that of 168 infertile men ( 16 ± 8 μIU/10~6sperm) (P <0.01). It was indicated that there was a significant positive correlation between the acrosin activity andthe sperm motility ( r ≥ 0.6534, P < 0.01) and a significant negative correlation between the sperm malformed rateand the WBC number ( r ≤ -0.5426, P < 0.01). The temperature and time of incubation and the sperm concentrationcould influence the assay results. Conclusion: Acrosin activity is an important index for the evaluation of male fer-tility. The approach developed by the authors is a simple method for the determination of acrosin activity.展开更多
文摘The very low cut-off value for sperm morphology of 4% morphologically normal spermatozoa, as proposed in the new edition of the World Health Organization （WHO） manual on semen analysis, is in agreement with recently published values and reflects the trend of a decline in reported mean values for normal sperm morphology. The reduced value for morphologically normal spermatozoa over the years may be due to several factors. The first is the introduction of strict criteria for the evaluation of sperm morphology. Other reasons may include the introduction of additional criteria for sperm morphology abnormalities and the suggested decrease in semen parameters because of increasing negative environmental influences. Although on its own the newly proposed very low normal value may not provide the strong predictive value for a males＇ fertility potential, as originally reported for sperm morphology evaluated according to strict criteria, a good predictive value can still be obtained if the holistic, strict approach for sperm morphology evaluation is followed together with additional sperm morphology parameters now available, because certain morphology patterns and sperm abnormalities are now known to be of strong prognostic value. In addition, better international standardization of the technical methodology, consensus on the interpretation of sperm morphology evaluation criteria and standardized international external quality control （EQC） schemes, are of utmost importance to maintain the good predictive value of sperm morphology.
基金financially supported by grants of the Key Projects in the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD14B00)the Guangdong Provincial Science and Technology Plan Key Project,China(2012A020100003,2015A050502043)
文摘Excessive use of agro-chemicals （such as mineral fertilizers） poses potential risks to soil quality. Application of organic amendments and reduction of inorganic fertilizer are economically feasible and environmentally sound approaches to de- velop sustainable agriculture. This study investigated and evaluated the effects of mineral fertilizer reduction and partial substitution of organic amendment on soil fertility and heavy metal content in a 10-season continually planted vegetable field during 2009-2012. The experiment included four treatments： 100% chemical fertilizer （CF100）, 80% chemical fertilizer （CF80）, 60% chemical fertilizer and 20% organic fertilizer （CF60＋OM20）, and 40% chemical fertilizer and 40% organic fertilizer （CF40＋OM40）. Soil nutrients, enzyme activity and heavy metal content were determined. The results showed that single chemical fertilizer reduction （CF80） had no significant effect on soil organic matter content, soil catalase activity and soil heavy metal content, but slightly reduced soil available N, P, K, and soil urease activity, and significantly reduced soil acid phosphatase activity. Compared with CF100, 40 or 60% reduction of chemical fertilizer supplemented with organic fertilizer （CF60＋OM20, CF40＋OM40） significantly increased soil organic matter, soil catalase activity and urease activity especially in last several seasons, but reduced soil available P, K, and soil acid phosphatase activity. In addition, continu- ous application of organic fertilizer resulted in higher accumulation of Zn, Cd, and Cr in soil in the late stage of experiment, which may induce adverse effects on soil health and food safety.
文摘Aim: To investigate a simple method for assaying acrosin activity for the evaluation of male fertility. Methods:The acrosin activity of 7.5 × 10~6 sperm without seminal plasma and acrosin activity inhibitors was assayed using N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA) and detergent (Triton X-100) as substrate. Results: The acrosin ac-tivity of 60 normal fertile men (35 ± 10 μIU/10~6 sperm ) was higher than that of 168 infertile men ( 16 ± 8 μIU/10~6sperm) (P <0.01). It was indicated that there was a significant positive correlation between the acrosin activity andthe sperm motility ( r ≥ 0.6534, P < 0.01) and a significant negative correlation between the sperm malformed rateand the WBC number ( r ≤ -0.5426, P < 0.01). The temperature and time of incubation and the sperm concentrationcould influence the assay results. Conclusion: Acrosin activity is an important index for the evaluation of male fer-tility. The approach developed by the authors is a simple method for the determination of acrosin activity.
