2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today’s blog focuses on silicon’s positive effects on the body.
Silicon was not originally regarded as an important element for human health, as it was seen to have a larger presence in (other) animal and plant tissue. It was not until a 2002 ‘The American Journal of Clinical Nutrition’ paper that surmised that accumulating research found that silicon plays an important role in bone formation in humans.
Silicon was first known to ‘wash’ through biology with no toxological or biological properties. However, in the 1970s, animal studies provided evidence to suggest that silicon deficiency in diets produced defects in connective and skeletal tissues. Ongoing research has added to these findings, demonstrating the link between dietary silicon and bone health.
Silicon plays an important role in protecting humans against many diseases. Silicon is an important trace mineral essential for strengthening joints. Additionally, silicon is thought to help heal and repair fractures.
The most important source of exposure to silicon is your diet. According to two epidemiological studies (Int J Endocrinol. 2013: 316783 ; J Nutr Health Aging. 2007 Mar-Apr; 11(2): 99–110) conducted, dietary silicon intake has been linked to higher bone mineral density.
Silicon is needed to repair tissue, as it is important for collagen synthesis – the most abundant protein in connective tissue in the body – which is needed for the strengthening of bones.
However, silicon is very common in the body and therefore it is difficult to prove how essential it is to this process when symptoms of deficiency vary among patients.
There has also been a plausible link between Alzheimer’s disease and human exposure to aluminium. Research has been underway to test whether silicon-rich mineral waters can be used to reduce the body burden of aluminium in individuals with Alzheimer’s disease.
However, longer term study is needed to prove the aluminium hypothesis of Alzheimer’s disease.
Organised by the National Human Genome Research Institute each year, National DNA Day in the US on 25 April celebrates the discovery of DNA’s double helix in 1953 and the completion of the Human Genome Project in 2003. Here, we explore the history of DNA and its discovery’s unparalleled effect on science, medicine and the way we now understand the human body.
Discovering DNA’s structure
Using the pictures that she had taken, Franklin was able to calculate the dimensions of the strands and found the phosphates were on the outside of the DNA helix.
Rosalind Franklin working in her lab. Image: Wikimedia Commons
Meanwhile, at the University of Cambridge, James Watson and Francis Crick deduced the double-helix structure of DNA, describing it as ‘two helical chains each coiled round the same axis’ following a right-handed helix containing phosphate diester groups joining β-D-deoxyribofuranose residues with 3’,5’ linkages.
The discoveries made by these scientists would propel the study of genetics into the modern science we know today. Crick and Watson were awarded the Nobel Prize for Physiology or Medicine alongside Maurice Wilkins, who worked with Rosalind Franklin, in 1962. You can read their original paper here.
Dolly the sheep
Dolly on display at the National Museum of Scotland, UK.
Dolly is arguably the most famous sheep in the world, having been the first mammal to be cloned from an adult cell. Born in 1996, Dolly was part of a series of experiments at the Roslin Institute in Edinburgh to create GM livestock that could be used in scientific experiments.
She was cloned using a technique called somatic cell nuclear transfer, where a cell nucleus from one adult is transferred into an unfertilised developing egg cell of another that has had its nucleus removed, which is then implanted into a surrogate mother.
The scientific legacy of Dolly the sheep. Video: Al Jazeera English
Dolly lived until 2003 when she was euthanised after contracting a form of lung cancer. Many speculated that Dolly’s early death was related to the cloning experiment but extensive health screening throughout Dolly’s life by the Roslin Institute suggest otherwise.
Her creation has led to further cloning projects and could be used in the future to preserve the populations of endangered or extinct species, and has led to significant developments in stem cell research.
In 2009, Spanish researchers announced the cloning of a Pyrenean ibex, which has been extinct since 2000, and was the first cloning of an extinct animal. Unfortunately, the ibex died shortly after birth but there have been a few successful stories since then.
The Human Genome Project
Beginning in 1990 and finishing in 2003, the Human Genome Project was an international research initiative that aimed to write the entire sequence of nucleotide base pairs that make up the human genome, including the mapping of all its genes that determine our physical and functional attributes.
The publicly funded $3bn project was able to map 99% of the human genome with 99.99% accuracy, which included its 3.2bn Mega-base pairs, 20,000 genes and 23 chromosome pairs, and has led to advancements in bioinformatics, personalised medicine and a deeper understanding of human evolution.