The first reported case of the rare mitochondrial haplotype H4a1 in ancient Egypt

From Springer Nature via Jisc Publications RouterHistory: received 2020-04-21, accepted 2020-09-04, registration 2020-09-28, online 2020-10-12, pub-electronic 2020-10-12, collection 2020-12Publication status: PublishedFunder: Donation endowment at the KNH Centre for Biomedical EgyptologyAbstract: Takabuti, was a female who lived in ancient Egypt during the 25th Dynasty, c.660 BCE. Her mummified remains were brought to Belfast, Northern Ireland, in 1834 and are currently displayed in the Ulster Museum. To gain insight into Takabuti’s ancestry, we used deep sampling of vertebral bone, under X-ray control, to obtain non-contaminated bone tissue from which we extracted ancient DNA (aDNA) using established protocols. We targeted the maternally inherited mitochondrial DNA (mtDNA), known to be highly informative for human ancestry, and identified 38 single nucleotide variants using next generation sequencing. The specific combination of these SNVs suggests that Takabuti belonged to mitochondrial haplogroup H4a1. Neither H4 nor H4a1 have been reported in ancient Egyptian samples, prior to this study. The modern distribution of H4a1 is rare and sporadic and has been identified in areas including the Canary Islands, southern Iberia and the Lebanon. H4a1 has also been reported in ancient samples from Bell Beaker and Unetice contexts in Germany, as well as Bronze Age Bulgaria. We believe that this is an important finding because first, it adds to the depth of knowledge about the distribution of the H4a1 haplogroup in existing mtDNA, thus creating a baseline for future occurrences of this haplogroup in ancient Egyptian remains. Second, it is of great importance for archaeological sciences, since a predominantly European haplogroup has been identified in an Egyptian individual in Southern Egypt, prior to the Roman and Greek influx (332BCE)

A study of pH-responsive microgel dispersions: from fluid-to-gel transitions to mechanical property restoration for load-bearing tissue

An interesting, and potentially important, challenge for colloid scientists is to design injectable dispersions that enable repair of damaged and degenerated tissue. This work presents a study of the ability of pH-responsive microgel particles to restore the mechanical properties of load-bearing soft tissue. Microgel particles are cross-linked polymer colloid particles that are swollen with solvent. The first part of the study consists of an investigation of the pH-triggered swelling of poly(EA/MAA/BDDA) (ethylacrylate, methacrylic acid and 1,4-butanediol diacrylate) microgel particles using photon correlation spectroscopy (PCS) measurements. The concentrated dispersions exhibit a strong fluid-to-gel transition when the pH is increased to above 6.0, i.e., above this pH they form gelled microgel dispersions. The swelling data are used to aid interpretation of the pH-triggered changes in the gel modulus, as probed using dynamic rheology. The second part of the study involves an investigation of the mechanical properties of artificially degenerated, model intervertebral discs (IVDs) containing gelled microgel dispersions. High concentration microgel dispersions were injected as fluids into the interior of degenerated IVDs and the pH increased by subsequent alkaline solution injection to cause particle swelling and dispersion gelation. Uniaxial compression data measured for the IVDs containing injected microgel dispersions indicate that the pH-induced particle swelling of the microgel restores the mechanical properties of degenerated IVDs to values similar to those measured for normal, non-degenerated, IVDs

Doubly crosslinked pH-responsive microgels prepared by particle inter-penetration: Swelling and mechanical properties

The structure and properties of conventional, singly crosslinked, pH-responsive microgel particles (SX microgels) have been extensively studied. Recently, doubly crosslinked microgels (DX microgels) have been reported. These are a new type of hydrogel that are constructed from covalently linked SX microgels. In this study we report for the first time an investigation of a new class of DX microgels which are pH responsive. The DX microgels were prepared using covalent linking of physically gelled dispersions of inter-penetrating, vinyl-functionalised microgels. The pH-responsive SX microgels used were poly(MMA/MAA/EGDMA) (methyl methacrylate, methacrylic acid and ethyleneglycol dimethacrylate) and poly(EA/MAA/BDDA) (ethylacrylate and butanediol diacrylate). The two microgel types considered (abbreviated as M-EGD and E-BDD) were functionalised with glycidyl methacrylate (GM). pH-triggered swelling of concentrated dispersions and free-radical coupling of the vinyl groups was used to prepare the DX microgels. The relationships between DX microgel composition and mechanical properties are investigated using dynamic rheology and swelling experiments. The DX microgels had storage modulus values of up to 20 kPa at a particle volume fraction (p) of 0.10. The yield strains (γ*) could be varied between 5 and 65%. The ability to tune the mechanical properties of the DX microgels using the degree of functionalisation of the parent GM-functionalised microgel, p and pH is demonstrated. We show that control of intra- and inter-particle crosslinking can be achieved using preparation conditions. The results are explained using a general relationship between the storage modulus and γ*. The new DX microgels have potential application as injectable gels for soft and load-bearing tissue repair. © 2011 The Royal Society of Chemistry