| 查看: 1100 | 回复: 8 | |||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | |||
[交流]
求翻译 各位兄弟姐妹谢谢啦
|
|||
|
While we were not the ?rst to coin the term hydroxyalu-minosilicate (HAS), we were the ?rst to demonstrate that the formation of HAS limited the biological availability of aluminum (1). We have since strived to understand as much as we can about the inorganic chemistry of HAS and their role in the biogeochemical cycle of aluminum (2, 3)and through our efforts we have provided a full description of one of the very few examples of the chemistry of silicic acid (4). The latter, in undersaturated solutions (<2.0 mmol/L) at pH below ca 10 is a neutral monomer of which the only known chemistry is (i) with ammonium molybdate to form the Keggin-like molybdosilicic acid complex (the basis for the spectrophotometric measurement of silicic acid) and (ii) with aluminum hydroxide to form HAS. The latter has been shown by us to proceed by a competitive condensation reaction at an hydroxyaluminum surface (4). In a recent paper in Environmental Science & Technology (5) the authors have used the term HAS but they have ascribed their role in limiting the biological availability of aluminum to an alternative reaction pathway involving the reaction of aluminum with polysilicic acids. Many metal cations are chelated by poly-silicic acids (6) and the chemistry is completely different from that of the formation of HAS. The authors should recognize that using the term HAS to describe the products of the reaction of aluminum with polymeric silicic acids is potentially confusing and misleading. In the same paper evidence is presented to support the detoxi?cation of aluminum in the digestive gland in snails by its intralysosomal binding by polymeric silicic acid. The suggestion seems to be that freshwater snails are natural biosilici?ers, capturing silicic acid and concentrating it in lysosomes prior to its deposition as amorphous silica. That freshwater snails deposit amorphous silica is an intriguing suggestion but not one, to my knowledge, that has been supported by experiment or observation. In addition, for such a mechanism to account for the detoxi?cation of aluminum there would need to be a further mechanism for the uptake of aluminum into lysosomes which were actively scavenging and concentrating silicic acid. Again, Occam’s razor would suggest that no such mechanism exists. The limited support provided for such a mechanism in this paper is analyses of a single inorganic particle isolated from a digestive gland of a snail exposed to aluminum. The analyses are qualitative and distinct from other similar analyses published by members of the same research group (7–9)in that there is no evidence of any sulfur. Energy dispersive X-ray spectrometry (EDX) suggested an excess of silicon over aluminum while electron energy loss spectrometry (EELS) showed some similarity with synthetic protoimogolite. There is a simple explanation for this observation. The aggregate in question is a phytolith (amorphous silica of plant/algal origin) which probably originated from the diet of the snail, and upon which are adsorbed HAS. The latter, since aluminum was present in excess of silicic acid in the culture solution, was probably HASA (or protoimogolite) in which the ratio of Si:Al would be ca 0.5 (10), an observation supported by EELS, and could have formed either in the external solution or, conceivably at least, in the digestive gland itself. I am at odds to understand why the authors have chosen to expound a mechanism of detoxi?cation of aluminum in the snail for which there is not, as yet, any scienti?c basis. The authors have shown quite clearly that aluminum is a neurotoxin in the snail and that the toxicity can be alleviated by silicic acid. Upon the basis of the science to-date the mechanism of amelioration is likely to be the same as that described in other biota, which is through the formation of HAS. [ Last edited by syy311 on 2011-3-21 at 16:44 ] |
回复此楼» 猜你喜欢
最近几年招的学生写论文不引自己组发的文章
已经有11人回复
-
写了一篇“相变储能技术在冷库中应用”的论文，论文内容以实验为主，投什么期刊合适？
已经有4人回复
-
需要合成515-64-0，50g，能接单的留言
已经有3人回复
-
中科院杭州医学所招收博士生一名（生物分析化学、药物递送）
已经有3人回复
-
临港实验室与上科大联培博士招生1名
已经有8人回复
-
想换工作。大多数高校都是 评职称时 认可5年内在原单位取得的成果吗？
已经有4人回复
-
带资进组求博导收留
已经有9人回复
» 抢金币啦！回帖就可以得到:
-
推荐给英语教学者的一本单词书《金鱼单词讲义：从26个拉丁字母到106万个英语单词》
+3/855
-
【CSC招生】拉瓦尔大学流体力学博士项目
+3/183
-
湖南师范大学医工交叉科研团队招收博士研究生
+1/182
-
湖北大学食品安全研究团队诚招博士后
+1/178
-
Analytical Science Advances 征稿中
+1/175
-
坐标北京不异地
+1/71
-
坐标上海，93年诚征女友
+1/69
-
宁波大学招聘科研助理1-2名
+1/52
-
暨南大学理工学院 光子技术研究院段宣明团队申请制读博招生
+1/37
-
国家青年人才叶立群教授课题组招收2026级博士研究生
+1/29
-
深圳大学李天任博士课题组研究生招生信息
+1/29
-
2026年中科院化学所优青 程靓团队招收有机化学、生物化学背景的博士研究生
+1/28
-
复旦大学彭慧胜院士团队 | 招聘有机合成方向博士后、博士生及科研助理
+1/22
-
SCI，计算机相关可以写
+1/15
-
经济学博士（金融方向）招生，211重点大学，2026年9月入学，申请-考核制。
+1/6
-
实验室研究员
+1/3
-
浙江大学杨林课题组招聘药物化学与有机合成方向博士后
+1/3
-
澳门大学 应用物理及材料工程研究院 孙国星课题组招收博士（2026/2027学年）
+1/3
-
澳科大药学院诚招2026年秋季药剂学/生物材料博士研究生
+1/2
-
維生素K2杂质1
+1/1
syy311(金币+2, 翻译EPI+1): 继续努力哦 后续跟上啊，谢谢哦 2011-03-21 19:33:58
|
While we were not the ?rst to coin the term hydroxyalu-minosilicate (HAS), we were the ?rst to demonstrate that the formation of HAS limited the biological availability of aluminum (1). We have since strived to understand as much as we can about the inorganic chemistry of HAS and their role in the biogeochemical cycle of aluminum (2, 3)and through our efforts we have provided a full description of one of the very few examples of the chemistry of silicic acid (4). 尽管我们不是第一个给出HAS的定义的，但是我们确是最先阐明HAS限制铝的生物学效应的机制的。我们尽力去了解关于HAS的无机化学特性以及他们在铝的生化循环中的重要作用。经过努力，我们发现了硅酸化学这个非常罕见的例子并能够对其进行完整的描述。 |
2楼2011-03-21 17:54:17
3楼2011-03-21 17:55:25
4楼2011-03-21 17:58:55
5楼2011-03-21 19:32:39
6楼2011-03-21 20:22:27
7楼2011-03-22 17:02:08
8楼2011-03-22 17:13:32
syy311(金币+1): 加油哦 呵呵 2011-03-23 14:22:07
|
The latter, in undersaturated solutions (<2.0 mmol/L) at pH below ca 10 is a neutral monomer of which the only known chemistry is (i) with ammonium molybdate to form the Keggin-like molybdosilicic acid complex (the basis for the spectrophotometric measurement of silicic acid) and (ii) with aluminum hydroxide to form HAS. The latter has been shown by us to proceed by a competitive condensation reaction at an hydroxyaluminum surface (4). 对于后者，在这个不饱和的溶液中（<2.0 mmol/L），且其pH值低于约10时，表现为一个中性的单体，这个单体有一已知化学性质，就是与钼酸铵形成的类铝的硅钼酸复合物（依据硅酸的分光光度值）及（II）从而与氢氧化铝形成了HAS。后者已被我们证明是由一个羟基铝的表面发生的竞争缩合反应所形成的。（4） |
9楼2011-03-22 20:54:20