Aqueous chemistry and biochemistry of silicon

我的研究计划的长期目标是探索水性硅（Si）的基础化学和生物化学，并将这些知识应用于材料科学、农业、健康和环境的进步。硅是地壳中含量仅次于氧的第二丰富的元素，而全球硅循环——一个地质、化学和生物过程的复杂相互作用——主要发生在水相中。该元素在营养上对一半的海洋生物量至关重要，因此是气候调节的重要因素。这对大多数高等生命形式也是有益的；例如，在哺乳动物中，饮食中的硅支持结缔组织健康并调节免疫和炎症反应。然而，人们对硅在分子水平上的生物活性知之甚少。由于硅水化学是大多数现代信息（半导体）、建筑（混凝土）和化学制造（催化剂）基础设施的基础，它显然也具有巨大的经济重要性。在接下来的五年里，我们将探索矿物形成的机制，例如，研究金属离子如何影响水硅酸盐的结构、平衡和化学交换动力学。我们还将继续研究硅酸盐碳水化合物化学，自从几年前我的小组发现它以来，它似乎越来越成为硅生物功能背后的化学机构。有证据表明，它甚至可能在生命起源中发挥了关键作用。此外，我们正在利用这种化学物质来制造添加剂（来自林产品废料），以提高混凝土的机械和化学性能，同时大大减少其碳足迹。由回旋加速器生产的硅-31的可用性将加速生物学研究。这种短寿命的放射性同位素将用于直接监测含硅分子在植物和动物中的吸收、转运和生物转化。我们还将研究Si作为交联剂（例如，在哺乳动物结缔组织和植物细胞壁中）或作为某些生化信号通路抑制剂的能力。此外，我们将研究二氧化硅纳米颗粒在哺乳动物中的免疫刺激作用以及二氧化硅微颗粒在植物中的传播能力。

The long-term objective of my research program is to explore the fundamental chemistry and biochemistry of aqueous silicon (Si), and to apply that knowledge for the advancement of material science, agriculture, health and the environment. Si is the second-most abundant element in the earth's crust after oxygen, and the global Si cycle - a complex interaction of geological, chemical and biological processes - occurs largely in the aqueous phase. The element is nutritionally essential for half the ocean's biomass and is therefore an important factor in climate regulation. It is also beneficial for most higher lifeforms; in mammals, for example, dietary Si supports connective tissue health and regulation of immune and inflammatory response. Very little is known about silicon's bioactivity at the molecular level, however. Because aqueous Si chemistry underpins most modern information (semiconductors), construction (concrete) and chemical manufacturing (catalysts) infrastructure, it plainly has great economic importance as well.    Over the next five years we will probe mechanisms of mineral formation, e.g., investigating how metal ions affect structure, equilibria and chemical exchange kinetics of aqueous silicates. We will also continue research of silicate-carbohydrate chemistry which, since its discovery by my group several years ago, appears increasingly to be the chemical agency behind Si biofunctionality. Evidence has emerged to suggest that it may even have played a pivotal role in the origin of life. As well, we are exploiting this chemistry to create additives (derived from forest product waste) that improve mechanical and chemical performance of concrete while dramatically reducing its carbon footprint. Biological studies will be expedited by the availability of cyclotron-produced silicon-31. This short-lived radioisotope will be used to directly monitor uptake, translocation and bioconversion of Si-containing molecules in both plants and animals. We will also investigate the ability of Si to serve as a cross-linking agent (in, e.g., mammalian connective tissue & plant cell walls) or as an inhibitor of certain biochemical signaling pathways. Additionally, we will examine the immunostimulatory role of silica nano-particles in mammals and the fire-propagating ability of silica micro-particles in plants.