| 查看: 1442 | 回复: 8 | |||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | |||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | |||
[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
2027广东省杰青
已经有5人回复
-
快农历七夕节了，轻松一下，男人悄悄话，女施主请不要进来。
已经有3人回复
-
哪位老哥知道今年的国自然具体哪一天放榜？
已经有9人回复
-
欢迎发来filecode的Mz6后的代码验证其规律
已经有72人回复
-
咱们一起用铁证分析2026国家社科基金中标与否
已经有26人回复
-
我的国基提前知道中了，可是同事的操作让我实在接受不了，怎么会有这样的人
已经有16人回复
-
有时候，自然基金真的不能太认真 （我的申报经验）
已经有12人回复
-
招聘 金属平磨液，抛光液研发工程师
已经有3人回复
-
时间戳又变了8-15
已经有23人回复
-
filecode=后面第一个是大写字母
已经有7人回复
» 抢金币啦！回帖就可以得到:
-
Data征稿（EI检索收录），选题方向：环境风险管理的数据分析
+5/420
-
北京信息科技大学机电工程学院硕士研究生招生线上宣讲会-8月16日
+5/255
-
西安交大马伟/王亚洲课题组诚聘联培博士和硕士学生多名-有机生物电子学方向
+1/183
-
山东征女友，坐标济南
+1/178
-
上海同城
+1/118
-
中国科学院空天院精密干涉测量团队 精密机械结构工程师招聘启事
+1/83
-
中国科学院空天院精密干涉测量团队 精密机械结构工程师招聘启事
+1/81
-
东南大学杰青/海优团队招聘催化方向博士后
+1/81
-
中国科学院空天院精密干涉测量团队招聘光学/算法/机械方向博士后/特别研究助理
+1/80
-
加拿大/英属哥伦比亚大学曹彦凯课题组招收博后 [机器人/控制方向]
+1/35
-
华南理工大学招2027年生物材料、药物递送申请考核制博士生
+1/26
-
西北工业大学 生科院 秦绪军课题组诚招博士后、博士/硕士研究生【长期有效】
+1/13
-
27级博士生 + 福州大学 + 经管学院 + 管理科学与工程（见贴则有指标）
+1/9
-
北理工集成电路杰青团队 | 诚招科助理
+1/7
-
北理工集成电路杰青团队 | 诚招科助理
+1/7
-
中国科学院生态环境研究中心环境工程相关方向招收保送硕士和联合培养博士和硕士研究生
+1/4
-
中国科学院生物物理研究所田勇课题组招聘联合培养生
+1/3
-
南京医科大学-冯璋课题组-招收2027级生化与分子生物学专业博士和硕士研究生
+1/3
-
海南大学化学院-科研助理招聘 （可读博，可与华中科技大学，天津大学联培）+博后招聘
+1/2
-
海南大学化学院—功能分子器件团队2027博士招生+博士后招聘
+1/2
4楼2011-03-21 17:58:55
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
5楼2011-03-21 19:32:39
