各种钙剂在人体内净吸收率比较示意图

生物钙素是1993年度中科院重大发明之一,是利用现代生物工程技术对生物鲜骨进行深加工后而获得的天然生物钙素。它能提高人的耐力、免疫力、记忆力、理解力和抗衰老能力。

^41Ca标记骨质疏松大鼠体内钙库法评价市售钙剂钙吸收率的研究

目的建立评价市售钙剂的钙吸收率方法。方法用去卵巢大鼠建立骨质疏松模型,41Ca标记大鼠体内钙库,原子吸收检测粪钙和血钙;以加速器质谱检测粪钙和血钙41Ca峰度。结果大鼠对该市售钙剂的表观吸收率为59.15%,净吸收率为69.18%,其中粪便内源钙占24.56%。结论41Ca标记体内钙库可得出净钙吸收率,且不受所评价的钙剂中钙的化学形式和种类的影响。此法能直接应用于市售钙剂钙吸收率的评价。

Growth and yield of rice as affected by transplanting dates and seedlings per hill under high temperature of Dera Ismail Khan, Pakistan

Studies were initiated for two consecutive years to find out the effect of time of transplanting and seedlings hill?1 on the productivity of rice in Dera Ismail Khan district of North West Frontier Province (NWFP), Pakistan. The experiment was laid out in a randomized complete block design with split plot arrangements. Main plots consisted of four transplanting dates viz. 20th and 27th of June and 4th and 11th of July while sub-plots contained 1, 2, 3 or 4 seedlings hill?1. Among transplanting dates, June 20th planted crop gave highest paddy yield and net return with 1 seedling hill–1. It explains that the use of more seedlings hill?1 not only adds to cost but is also a mere wastage of natural resources. Based on research findings, we conclude that the use of 1 seedling hill?1 is most appropriate for timely sowing otherwise 4 seedlings hill–1 should be used to compensate for the yield gap in late transplanted rice.