生本教育开创山区职业教育的春天

我校是粤北山区一所朝气蓬勃、富有生命力的职业学校。近三年来,学校先后开展了创新思维教育、心理健康教育、信息技术运用教育、校企合作办学、“订单式培养模式”、“双证书毕业”、特长教育等方面的研究,取得一定的成绩,社会声誉日益提升,办学规模快速增长。但相应的配套措施却未能完全跟上学校发展规模,教育教学改革迫在眉睫。学校在发展,学生在增加,因区域经济原因,教师数量却没有相应增加,无法满足学校发展的需要,压在教育教学肩上的担子更重,教师工作量增大,工作压力增强。学校要做强做大,需要更加科学更加人性更加符合职业教育的教育教学思想指导工作,解决学校发展中遇到的问题。2007年9月,我校有幸被确定为全省15所生本教育试点学校之一,一股春风吹到了粤北山区,吹到了曲江职业技术学校,给学校的教育教学改革带来了春天的希望。     

练后深思效率高

近几年高考生物试题特点是：强调基础，注重运用，尤其突出学生的创新能力，试题的灵活性和开放性，以及思维的发散性、创新性都在逐年加强。所以，在高考备考过程中，练习和检测是巩固知识、加深理解和培养能力的一个重要手段。要巩固和扩大练习的效果，提高学习效率，练后深思是一种有效的学习方法。那么，练后应思考哪些问题呢?     

Interaction of catechins with aluminum in vitro

INTRODUCTION nd that catechin-metal complexes had strong bio- activities (Midori et al., 2001). But, it is not clear Because of the aluminum accumulation in tea what the mechanism of combination of catechinsplant, the safety hazard of aluminum absorption with aluminum ion is (Inoue et al., 2002), and alsowhile drin…     

Interaction of catechins with aluminum in vitro

Tea is one of the most popular beverages, consumed by over two thirds of the world's population; but the aluminum accumulation property of tea plant is becoming the focus of many researches because of aluminum's known adverse effect on human health. Investigation of the interactions of catechins with Al3 showed that during the interaction of catechins with Al3 , the UV-vis spectrum of catechins was changed. Absorption of EGCG at 274 nm decreased and increased at 322 nm; EC and C's at 278 nm changed little. The ratio of Al3 to EGCG was 1:1 in pH 5.0 buffer solution; in pH 6.2 buffer solution, the ratio in the Al-EGCG complex was 1:1. Interestingly, while the ratio reached to over 2, after the complex of Al-EGCG started polymerization, the ratio in the polymer was 2:1. In pH 6.2 buffer solution, the complex behavior of C with Al3 was the same as that of EGCG, with a little difference for EC. When the ratio of Al3 to EC was <1, the complex in ratio was 1:2, but, the complex polymerized when the ratio of Al3 to EC was >1. It was found that the ratio of Al3 to EC in the polymer was 1:1. Polymerization of Al-catechin complexes might reduce aluminum absorption in the intestine. Kow value was also employed to study the properties of aluminum species in tea infusion (at gastric and intestine pH condition) and the effect of catechins and tea polyphenols on Kow in buffer solution. Results showed that Kow value rose much higher at the intestine pH than at the gastric pH. Tea polyphenols and catechins could greatly reduce aluminum Kow value in acetic buffer, indicating that these compounds may reduce aluminum absorption during tea intake.