复配阻垢剂对碳酸钙阻垢效果及垢晶微观形貌影响

针对石南1631注水井结垢问题,以该注水井水样分析数据为基础,应用Scale-Chem结垢预测软件对该注水井的结垢类型进行了预测,得到该注水井的主要结垢类型为碳酸钙垢,并与现场垢样分析结果进行了对比。为了减缓结垢对注水的影响,选用五种阻垢剂对该注水井水样开展了阻垢效果研究。在阻垢剂单剂对注入水水样阻垢效果实验研究的基础上,将优选出的阻垢剂PESA与DTPMPA以2:1 复配,当阻垢剂浓度为80mg/L时,阻垢率达到90.26%。为明确复配阻垢剂的阻垢机理,对加入不同复配阻垢剂浓度前后形成的垢晶进行了扫描电镜分析与X-射线衍射分析,分析结果表明,复配阻垢剂对碳酸钙晶体的形貌与晶体粒径均有一定程度的影响,在实验所用复配阻垢剂浓度范围内,阻垢剂浓度越高,碳酸钙晶体的平均粒径越小;复配阻垢剂主要通过螯合增溶与晶格畸变,在碳酸钙垢的形成过程起到了抑制作用。     

Ca^2＋对番红花叶片中活性氧代谢的影响

以单子叶植物番红花为材料,研究了钙离子对其活性氧代谢的影响.随钙水平降低,除SOD外,膜保护酶(POD,CAT)和抗氧化剂(AsA)均一直下降,导致O-2.产生速率、膜脂过氧化作用、质膜透性增加.说明钙离子对番红花活性氧代谢有明显的影响.     

三元混配配合物分子内的芳环堆积作用（Ⅴ）：Ca（Ⅱ）／核苷酸／ …

用ｐＨ电位滴定法测定了Ｃａ（Ⅱ）与腺苷５‘－三磷酸和芳香杂环碱Ａ形成的三元混合配合物Ｃａ（Ａ）（ＡＴＰ）＾ｎ－（ｎ＝２或３）的稳定常数９Ｉ＝０．１,ＫＮＯ３,２５℃）,比较了三元混配配合物与三元配合物的稳定性大小,其差值ΔｌｇＫｃａ要比预期的统计值ｌｇＫｓｔ来得大。     

小鼠卵母细胞生发泡破裂前的钙离子波动及分布

用显微操作技术将Ｃａ＾２＋特异荧光染料Ｃａｌｃｉｕｍ ｇｒｅｅｎ＾ＴＭ－１注射入ＧＶ期卵母细胞的细胞质内,在激光扫描共聚焦显微镜下观察生发泡破裂前Ｃａ＾２＋的时间和空间分布的变化,利用Ｌａｓｅｒ ｓｈａｒｐ软件进行分析,发现一种有规律的Ｃａ＾２＋波动,其波动周期约为９０ｓ。卵母细胞内Ｃａ＾２＋的分布并不均匀,核膜周围的Ｃａ＾２＋浓度了高,细胞质中次之,而生发泡内部Ｃａ＾２＋浓度最低。     

The discovery of α-Klotho and FGF23 unveiled new insight into calcium and phosphate homeostasis

The traditional view of calcium homeostasis is that it is maintained by two essential reactions. First, changes in extracellular Ca²⁺ are sensed in several distinct cell types, stimulating the secretion of parathyroid hormone (PTH), 1,25(OH)₂ D and calcitonin in response to the body’s requirement. Second, these calcitropic hormones then act on the calcium-translocating cells of the kidney, bone, and intestine to restore calcium balance. Recent progress indicates that α-Klotho and fibroblast growth factor (FGF) 23 are key players that integrate the multi-step regulatory system of calcium homeostasis that rapidly adjusts the extracellular calcium concentration and continuously maintains its concentration within a narrow physiological range. α-Klotho and FGF23 are also found to be major players in the regulatory system of phosphate homeostasis. Here, the demonstration of the molecular functions of α-Klotho and FGF23 has recently given new insight into the field of calcium and phosphate homeostasis. Received 3 April 2008; received after revision 23 May 2008; accepted 5 June 2008     

超声波对碳酸钙积垢过程的影响

研究了超声波艰某些无机盐水溶液和含有蔗糖的无机盐水溶液的表面张力和电导率,以及对ＣｕＣＯ３积垢速率和性状的影响。结果表明,超声波作用可以明显降低换热器表面ＣａＣＯ３积垢速率,有效地减缓、ＣａＣＯ３积垢,最后探讨了超声波减缓ＣａＣＯ３积垢的机理。     

头孢唑啉钠对HeLa细胞内Ca2＋浓度的影响

钙离子作为生物体内重要的信使,参与、调节生命体内的各种生理活动．通过抗生素头孢唑啉钠对HeLa细胞的刺激作用,揭示出抗生素类药物能够作为刺激物刺激细胞,而细胞则通过细胞内钙库钙的释放,使胞内Ca2＋浓度升高作为应答．     

Hierarchical porous calcium carbonate microspheres as drug delivery vector

CaCO3 crystals with different hierarchical structure were fabricated by the precipitation of CaCO3 in an aqueous solution containing guar gum (GG). Through adjusting a range of parameters, the size distribution and microstructure of CaCO3 were well controlled. Results showed that GG facilitated the formation of the hierarchical hollow sphere through assembling of nanocrystals, while inhibited the growth of CaCO3 crystals and restrained phase transition from calcite to vaterite at high concentration of GG (CGG) condition; Moreover, increasing reaction temperature led to larger particles and stable crystalline phase formed. According to the results, a morphology map was presented. Furthermore, Drug loading and releasing results ensured porous CaCO3 microspheres a promising vector for drug delivery.     

一次溶样连续测定彝药七底中钙镁铁锌

用原子吸收光谱法测定了彝药"七底"中的Ca、Mg、Fe和Zn元素的含量。结果表明,该方法的相关系数≥0.9943;测定样品的相对标准偏差为2.84%～4.35%;样品的回收率在94%～105%之间,表明该方法准确、可靠。     

NaBH_4－CaCl_2体系还原羧酸的研究

ＮａＢＨ４－ＣａＣｌ２体系在ＴＨＦ－甲苯混合溶剂中，于９５～１００℃下反应，能够将某些羧酸还原为相应的醇。