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Journal of Soils and Sediments - Carbon capture and storage (CCS) has been frequently discussed as a strategy for meeting CO2 emission reduction and its targets. However, some critical issues have...  相似文献   
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Mammalian fertilization requires sperm to penetrate the cumulus to reach the oocyte. Although sperm hyaluronidase has long been believed to participate in the penetration process, our previous works revealed that neither of two sperm hyaluronidases, SPAM1 and HYAL5, are essential for fertilization. In this study, we have produced double-knockout mice lacking SPAM1 and either one of two sperm serine proteases, ACR and PRSS21, and characterized the mutant sperm. The SPAM1/ACR- and SPAM1/PRSS21-deficient males were fertile, whereas epididymal sperm of the mutant mice exhibited a reduced capacity to fertilize the oocytes in vitro. Despite normal motility, the ability of sperm to traverse the cumulus matrix was more severely impaired by the loss of SPAM1 and ACR or SPAM1 and PRSS21 than by the loss of only SPAM1. Moreover, SPAM1/ACR- and SPAM1/PRSS21-deficient sperm accumulated on the surface (outer edge) of the cumulus more abundantly than SPAM1-deficient sperm. These results suggest that ACR or PRSS21 or both may function cooperatively with SPAM1 in sperm/cumulus penetration.  相似文献   
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OBJECTIVE: To investigate factors influencing the practices of partial breast-feeding (PBF) and exclusive breast-feeding (EBF). DESIGN: A national, cross-sectional survey was conducted among married women aged 15-49 years from May to August 2003. SETTING: South Korea. SUBJECTS: A total of 865 mothers answered questions regarding the feeding practices of their youngest baby, born between January 2001 and May 2003. RESULTS: The initiation rates of PBF and EBF were 81% and 63%, respectively. However, the median durations of PBF and EBF were very short: 12 and 8 weeks, respectively. According to stepwise logistic and Cox regression analyses, the more prenatal care women received, the more likely they were to initiate PBF and EBF but the less likely to continue EBF. Delivery by Caesarean section decreased the initiation of PBF and EBF. The mother's education level and employment status before marriage, the amount of prenatal care, delivery method and baby's status at birth affected breast-feeding initiation, whereas the amount of prenatal care influenced breast-feeding duration. CONCLUSION: To promote breast-feeding, education and campaigning on the importance of continued breast-feeding should be provided to the general public, particularly to health workers in maternity units.  相似文献   
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