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1
Kammer, Martin. "Schwingungsspektroskopische Untersuchungen zur Biomineralisation". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-97585.
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Die Schwingungsspektroskopie, besonders die Raman-Spektroskopie, stellt ein wichtiges Werkzeug für Untersuchungen von Biomineralien dar. Raman-Spektroskopie wurde zur Untersuchung der organischen und anorganischen Bestandteile von Schwammskeletten eingesetzt. Die Raman-Spektroskopie trug auch zur Charakterisierung von biomimetischen Silikat-Präzipitaten bei.
Durch ortsaufgelöste Raman-Spektroskopie konnte erstmalig die Verteilung von organischem Material in den extrahierten Silikatzellwänden von Kieselalgen nachgewiesen werden. Die ortsaufgelöste Raman-Spektroskopie wurde ebenfalls zur Untersuchung des SERS-Effekts an Zellwänden von Kieselalgen an die Silber-Nanopartikel gekoppelt waren eingesetzt.
2
Kirkham, Sara Jane. "Model studies of biomineralisation". Thesis, Nottingham Trent University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245634.
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3
Corkery, Robert, i robert corkery@anu edu au. "Artificial biomineralisation and metallic soaps". The Australian National University. Research School of Physical Sciences and Engineering, 1998. http://thesis.anu.edu.au./public/adt-ANU20080124.190014.
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In this thesis, geometry is used as a basis for conducting experiments aimed at growing
and arranging inorganic minerals on curved interfaces. Mineralisation is directed using
crystalline and liquid-crystalline metallic soaps and surfactant/water systems as
templates.¶
A review of the history, syntheses, structure and liquid crystallinity of metallic soaps
and other amphiphiles is presented as a foundation to understanding the interfacial
architectures in mesostructured template systems in general.¶
In this study, a range of metallic soaps of varying chain length and cation type are
synthesised and characterised to find potentially useful templates for mineral growth.
These include alkaline-earth, transition metal, heavy metal and lanthanide soaps. These
are systematically characterised using a variety of analytical techniques, including
chemical analyses, x-ray diffraction (XRD) infrared spectroscopy (IR) and differential
scanning calorimetry (DSC). Their molecular and crystal structures are studied using
transmission electron microscopy (TEM), cryo-TEM, electron diffraction (ED), electron
paramagnetic spin resonance (EPR), absorption spectroscopy (UV-VIS), high resolution
laser spectroscopy, atomic force microscopy (AFM), nuclear magnetic resonance
spectroscopy, scanning electron microscopy (SEM), electron dispersive x-ray analysis
(EDXA), thermal gravimetric analysis (TGA) and magnetic measurements. Models for
the molecular and crystal structures of metallic soaps are proposed. The soaps are
predominantly lamellar crystalline or liquid crystalline lamellar rotor phases with tilted
and/or untilted molecular constituents. These display evidence of varying degrees of
headgroup organisation, including superstructuring and polymerisation. A single crystal
structure is presented for a complex of pyridine with cobalt soap. Simple models for
their structure are discussed in terms of their swelling properties in water and oils.
Experiments are also presented to demonstrate the sorbent properties of aluminium
soaps on oil spills.¶
The thermotropic liquid crystallinity of alkaline earth, transition metal, heavy metal and
lanthanide soaps is investigated in detail. This is done to assess their suitability as
templates, and to document their novel thermotropic behaviour, particularly the
relatively unknown lanthanide soaps. Liquid crystalline behaviours are studied using
high-temperature XRD (HTXRD), hot-stage optical microscopy and DSC. Models for a
liquid crystalline phase progression from crystals to anisotropic liquids are discussed in
terms of theories of self-assembly and interfacial curvature. The terminology required
for this is drawn from various nomenclature systems for amphiphilic crystals and liquid
crystals. General agreement with previous studies is reported for known soaps, while
liquid crystallinity is demonstrated in the lanthanide and some non-lanthanide soaps for
the first time. A general phase progression of crystalline lamellar through liquid
crystalline lamellar to non-lamellar liquid crystalline is discussed in terms of models
concerned with the molecular and crystal structures of the soaps and their phase
transitions via headgroup and chain re-arrangements.¶
Experiments aimed at guiding growth of metal sulfides using metallic soaps as
templates are described, and a model for this growth is discussed. Metal sulfides have
been successfully grown by reacting crystalline and liquid crystalline transition metal
and heavy metal soaps with H2S gas at room temperature and at elevated temperature.
These have been characterised using XRD, TEM, ED and IR. Sulfide growth is
demonstrated to be restricted and guided by the reacting soap template architecture.
Zinc, cadmium, indium and lead soaps formed confined nanoparticles within the matrix
of their reacting soap template. In contrast, curved and flat sheet-like structures, some
resembling sponges were found in the products of sulfided iron, cobalt, nickel, copper,
tin and bismuth soaps. A model to explain this behaviour is developed in terms of the
crystal and liquid crystal structures of the soaps and the crystal structures of the metal
sulfide particles.¶
Liquid crystalline iron soaps have been subjected to controlled thermal degradation
yielding magnetic iron oxide nanoparticles. Some XRD and TEM evidence has been
found for formation of magnetic mesostructures in heat-treated iron soaps. Models for
the molecular and liquid crystalline structure of iron soaps, their thermotropic phase
progression and eventual conversion to these magnetic products are discussed.
Systematic syntheses of mesoporous silicates from sheeted clays are discussed.¶The
templates that have been used are cationic surfactants and small, organic molecular
salts. Experiments are reported where a cooperative self-assembly of
surfactant/water/kanemite plus or minus salt and oils yields 'folded sheet materials'
(FSM'S). Templating of kanemite has also been achieved using cobalt cage surfactants.
A theoretical prediction of the specific surface areas and specific volumes of
homologous sets of FSM's gave excellent agreement with measured values. The
geometry and topology of the mesostructures are discussed. A theoretical model is also
discussed regarding the curvature found in the sheets of natural clays , and results of
templating clays and silica using metallic soaps are presented. Experiments and a model for low temperature nucleation and growth of microporous silicalite-1 are described in
terms of silica templating by water clathrates.¶
Finally, the problem of finding minimal surface descriptions of crystal networks is
addressed. Combinatoric methods are used to disprove the existence of possible
embeddings of type I and II clathrate networks in non-self intersecting periodic minimal
surfaces. The crystal network of the clathrate silicate, melanophlogite is successfully
embedded in the WI-10 self-intersecting surface. Details of a previously unreported,
genus-25 periodic surface with symmetry Im3m are discussed.
4
Brookshaw, Diana Roumenova. "Mineralisation and biomineralisation of radionuclides". Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/mineralisation-and-biomineralisation-of-radionuclides(6c4c0f0e-96f6-4960-a1aa-9c0aa6eaa126).html.
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Management of contamination from industrial activities and wastes from nuclear power generation and weapons development are arguably amongst the greatest challenges facing humanity currently and into the future. Understanding the mobility of toxic radioactive elements is essential for successful remediation strategies and safe management of our nuclear waste legacy (DEFRA, 2008). Interactions between minerals and radionuclides, such as sorption and precipitation, govern the mobility of the contaminants through the subsurface environment. Microbial metabolic processes (redox cycling or release of metabolites) have the potential to affect drastically these abiotic interactions. Microbially-driven mineralisation processes could provide long-term solid-phase-capture solutions to radionuclide contamination problems and support safety cases for geological disposal of radioactive waste. The recent advancements at the intersection between mineralogy, microbiology and radiochemistry were reviewed with the aid of a cluster analysis (Self-Organising Map). This is a relatively novel method of creating a map of the ‘research landscape’ which provides a visual summary of the reviewed literature and can help to identify areas of promising and active research as well as less researched interdisciplinary areas. It is the first time this tool has been applied to research literature on this interdisciplinary topic, and it highlighted the need to gain further understanding of ternary systems including bacteria, minerals and radionuclides. The analysis showed that phyllosilicates are of interest, but few studies have explored the properties of the Fe(II)/Fe(III)-containing micas biotite and chlorite. The ability of model Fe(III)-reducing microorganisms to reduce Fe(III) in biotite and chlorite was demonstrated in batch model systems. In chlorite, approximately 20% and in biotite ~40% of the bulk Fe(III) was transformed to Fe(II) by this reduction. To our knowledge, this is the first study to show the availability of Fe(III) in biotite for such reduction and the ability of the model organism Shewanella oneidensis MR-1 to conserve energy for growth using Fe(III) in biotite as the sole electron acceptor. The microbial Fe(III) reduction led to a decrease in the sorption of Cs and Sr by chlorite, but had very little effect on sorption to biotite. The data indicate that remediation strategies based on microbial Fe(III) reduction may exacerbate the movement of Cs and Sr through strata where sorption is dominated by phyllosilicates, particularly chlorite. While microbial Fe(III) reduction had only a slight effect on the sorption properties of biotite and chlorite, it drastically altered their redox properties. Previously bioreduced biotite and chlorite readily removed Cr(VI), Tc(VII) and Np(V) by surface-mediated reduction. The minerals were also able to reduce U(VI), but solution chemistry affected this reaction, reflecting the complexity of the biogeochemistry of this actinide. Overall, this work highlights the importance of decoupling microbial and geochemical processes in developing a holistic understanding of radionuclide behaviour in the environment. This body of work forms the thesis is entitled ‘Mineralisation and Biomineralisation of radionuclides’, and was prepared by Diana Roumenova Brookshaw for submission in August 2013 for the degree of Doctor of Philosophy to the University of Manchester.
5
Wang, Anqi. "Bacterial biofilms and biomineralisation on titanium". Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1562/.
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This study investigated bacterial interactions with titanium, and evaluated the use of Serratia biomineralisation to produce a hydroxyapatite (HA) coating on titanium. Adherence of Gram-positive Staphylococcus epidermidis and Streptococcus sanguinis and Gram-negative Serratia sp. NCIMB 40259 and Escherichia coli was compared on commercially pure titanium, Ti6Al4V alloy, pure aluminium and pure vanadium. Grain boundaries, grain orientation and alloy phase structure did not influence adhesion or early proliferation. Adherence of all four strains was equivalent on pure titanium and Ti6Al4V and inhibited on pure aluminium. Serratia biomineralisation was used to introduce a crystalline coating on Al\(_2\)O\(_3\) grit blasted titanium discs and a porous titanium mesh. The porous coating consisted of micro-scale spheres composed of nano-scale calcium deficient HA. Embedded alumina particles and alkali treatment did not noticeably alter precipitation of Serratia HA, nor the structure of the coating in comparison with non-treated substrates. Coatings were retained after sintering at 800\(^\circ\)C in argon, although the original curved plate-like crystals changed to nano-scale β-tricalcium phosphate particles. A phosphorous-rich diffusion zone formed at the coating-titanium interface. This biomineralised coating may have applications for coatings of implants in non load-bearing sites, and other non-clinical applications where a high surface area is the major concern.
6
Russell, Benedict John. "Microscopic mechanisms of iron oxide biomineralisation". Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612041.
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7
Cornelius, Frauke. "Synthese von Modellsystemen und deren Einfluss auf die Biomineralisation von Siliciumdioxid". Stuttgart Fraunhofer-Verl, 2009. http://d-nb.info/995724113/04.
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8
Wilcock, Jennifer Ruth. "Biological minerals formed from strontium and barium sulphates". Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238199.
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Hall, Mandy. "Investigation of pathological biomineralisation using Raman microscopy". Thesis, Northumbria University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384965.
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Glynn, Sarah Elizabeth Johanna. "Sulphide alteration and biomineralisation in metalliferous sediments". Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416481.
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11
Maginn, Ellis. "Biomineralisation and geochemistry of hydrothermal vent fauna". Thesis, University of Southampton, 2002. https://eprints.soton.ac.uk/426772/.
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Hydrothermal ventfauna, particularly vestimentiferan and polychaete worm tubes, are occasionally preserved in the geological record. The early stages of mineralisation are particularly important in defining whether or not preservation will occur, and they are poorly understood. This dissertation describes 3 separate studies of ventfauna undergoing early mineralisation associated with active seafloor vent systems. Tube samples of the polychaete worm Alvinella pompejana collected from 13°N on the East Pacific Rise were studied to identify the processes occurring during early sulphide mineralisation. Iron sulphide mineralisation is present within the walls of the organic dwelling tube, and is induced by microbialfauna preserved within the tube micro-layers. A laminated tube structure wasformed, comprising alternating layers of tube material and microbially templated iron sulphide-rich interlayers. The iron monosulphides mackinawite and greigite, have been identified as intermediate phases that occur as precursor minerals during theformation ofpyrite. Later marcasite mineralisation is observed toform over some of the pyritised organic layers. Later stagemineralisationprocesses in a selection offossil tube structures recoveredfrom an extinct sulphide mound on the Southern East Pacific Rise were studied. The similarity to existingfaunal assemblages suggests that these structures were also associated with Alvinella sp. polychaete worms. Two generations ofpyrite were identified along with a later stage chalcopyrite phase. Fine scale variability in tube wall geochemistry was demonstrated with electron micro-probe transects across the structures and this is inferred to reflect early mineralisation processes as identified in living polychaete worms. Sulphur isotope analyses of the different sulphide phases gave δ³⁴S values higher than any previously measured for chimney structures on a sediment-free ridge setting (δ³⁴S = 3.8-10.8‰). A two stage model is proposed whereby early pyrite / marcasite laminae originally laid down in association with biogenic tube structures, are replaced by euhedral pyrite, and later stage primary chalcopyrite precipitation. A study ofRidgea piscesae from the Juan de Fuca Ridge demonstrated that silicification processes proceed so rapidly that the vestimentiferan tubes can become mineralised during the worm's life cycle. The organic component of the worm tube is rapidly replaced by amorphous silica which undergoes dewatering toform opal-A. This mineralisation is then overgrown by barite laths, and microbially templated amorphous silica. With time, prograde mineralisation causes the further precipitation and consequent overprinting of the primary mineral suite with iron- and zinc-sulphides. Other observations from samples studied here include micro-tubes (-50 jjm length) associated with adult R. piscesae and a silicified mucus lining to inhabited worm tubes. Associated with the mucus lining is a ligament which runs along the inside of the tube, and is tentatively inferred to be a form of anchor, allowing the worm to rapidly retract into the tube when threatened. Once mineralisation has replaced the organic tube material there is scope for the tube structure to be preserved along with the host sulphide body. Understanding of the mechanisms of early sulphide and silica/barite mineralisation as inferred from detailed observations and measurements of tube worm samples is an important contribution to the growing field of hydrothermal palaeobiology.
12
Horstmann, Sandra. "Streng biomimetische Modellsysteme für die Biomineralisation von Siliciumdioxid". kostenfrei, 2006. http://www.digibib.tu-bs.de/?docid=00004674.
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England, Jennifer Katherine. "Calcium carbonate biomineralisation in disparate systems : common mechanisms?" Thesis, University of Glasgow, 2005. http://theses.gla.ac.uk/4024/.
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This study considers the extent to which four calcium carbonate biomineral systems share common characteristics. Within the sample set, there is a range of ultrastructures and two types of calcium carbonate polymorph (calcite and aragonite). The mini survey includes three invertebrate systems: two members of the Phylum Brachiopoda; the articulated brachiopod Terebratulina retusa (Subphylum Rhynchoenlliformea) and the inarticulated brachiopod Novocrania anomala (Subphylum Craniiformea), and a member of the Mollusca, the bivalve Mytilus edulis. The fourth, outlying vertebrate system, is the eggshell of the domestic fowl, Gallus gallus. The minor element composition of each of the four systems is considered in the context of mineral ultrastructure. The shell of T. retusa comprises two layers; a primary layer of acicular calcite and an underlying secondary layer composed of calcite fibres. In thin section, a variation between the upper and lower portions of the secondary layer is evident. The concentrations of magnesium, sulphur and strontium are significantly greater in the primary layer of the shell. Magnesium concentration also differs between the upper and lower regions of the secondary layer with higher concentration in the upper portion of the secondary layer. The shell of N. anomala consists of two layers; a primary layer of acicular calcite and a secondary layer of calcite semi-nacre. N. anomala has a high magnesium calcite shell. The concentration of minor elements does not differ significantly between the primary and secondary layers. Two calcium carbonate polymorphs occur in the M. edulis shell with an outer calcite layer and an inner aragonite layer. Magnesium concentration is higher in the calcite layer while strontium concentrations are greater in the aragonite layer. Sodium concentration gradually decreases across the calcite layer from the outer surface to the calcite/aragonite boundary and increases in the aragonite layer.
14
Lutz, Katharina. "Multinukleare NMR-spektroskopische Untersuchungen zur Biomineralisation bei Diatomeen". kostenfrei, 2008. http://www.opus-bayern.de/uni-regensburg/volltexte/2008/1034/.
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Oder, Stephanie. "Produktion und Charakterisierung biogener anorganischer, nanoskaliger und nanostrukturierter Partikel". Karlsruhe Univ.-Verl. Karlsruhe, 2007. http://d-nb.info/984881395/34.
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Chang, Veronica Tzu-Chun. "Mg and Ca isotope fractionation during CaCO₃ biomineralisation". Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269953.
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Hughes, Nigel P. "In vivo and in vitro studies of biomineralisation processes". Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279881.
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Jennions, Suzanne M. "The effect of environmental change on bivalve mollusc biomineralisation". Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685038.
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Anthropogenic C02 release is leading to a wide range of oceanic environmental changes that may influence the survivability of marine organisms in the future. Environmental change varies regionally, and Southern Ocean calcifying organisms are considered to be particularly at risk from change, due to low pre-existing pH conditions and rapidly increasing temperatures. UVic model data from the Southern Ocean is used to assess environmental change in the region, and shows the importance of considering the variability as well as the magnitude of change. Since pre-industrialisation, the four Southern Ocean locations analysed showed a modern pH range entirely outside the historic range. The southern west Antarctic Peninsula region is considered the most vulnerable due to historic environmental stability, increased variability in the modern, and the widest gap between historic and modern carbonate chemistry variability envelops. The geochemistry and crystal structure of eight species of Antarctic bivalves were investigated, and four of these species were used to assess organism response to environmental change since pre-industrialisation from the western Antarctic Peninsula to South Georgia. Bivalve response varied between and within species: Lissarca miliaris showed a decrease in shell robustness over time; Lissarca notorcadensis showed one instance of no change and another of increased robustness; and Limatula pygmaealLimatula ovalis showed no change. There was no correlation between sites identified as vulnerable in the UVic model, and bivalve response. Mytilus californianus, a temperate bivalve species, from Tatoosh Island on the NW Pacific coastline of the USA, were similarly tested as pH has declined in the region four times faster than the global average. Bivalve shells showed a change in biomineralisation, resulting in increased robustness from the historic to the modern. The variability in response illustrates that some species have sufficient plasticity to be unaffected by environmental change, some may struggle to survive in future oceans and others have the capacity to adapt on short timescales.
19
Galloway, Johanna Marie. "Biotemplating arrays of nanomagnets using the biomineralisation protein Mms6". Thesis, University of Leeds, 2012. http://etheses.whiterose.ac.uk/3152/.
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High quality magnetic nanoparticles (MNPs) are used in applications such as electronic data storage. Current methods for synthesising the consistent MNPs required use high temperatures, harsh chemicals and bespoke equipment. As this is energy intensive, expensive and not very environmentally friendly, cheaper and „greener‟ alternatives are being sought. Mms6 is a biomineralisation protein from a magnetic bacterium (Magnetospirillum magneticum AMB-1), which is able to biotemplate the formation of uniform cubo-octahedral magnetite nanoparticles in vitro under mild reaction conditions. The N-terminal section is hydrophobic, and may cause the protein to self-assemble in aqueous solution. This self-assembly may facilitate the biotemplating ability of the protein, but it is the acidic C-terminal section of the protein that is the most important for binding iron and templating uniform MNPs. Attachment of Mms6 via the N-terminus to a micro-contact printed (μCP) patterned self-assembled monolayer (SAM) allows the protein to biotemplate uniform, ferrimagnetic magnetite MNPs in situ. These biotemplated MNPs were investigated with magnetic force microscopy (MFM), which found that they form multi-particle zones of attraction and repulsion. This is likely to be due to exchange-coupling of MNPs on the surface, with the long-axis of these magnetic features running parallel to the long axis of the assembly of patterned nanoparticles. As magnetite is magnetically soft, the system was doped with cobalt to increase the coercivity of the MNPs, both when templated onto a surface and in a bulk solution. To create biotemplated MNPs for use in data storage, a high coercivity is necessary to ensure that the magnetic orientation, and therefore the data recorded, is retained. The work presented here demonstrates that biotemplating can be used to produce high quality magnetic materials under far milder conditions than required in current industrial synthesis techniques, which should allow the development of more environmentally friendly bioinspired devices in the future.
20
Becker, Alexander. "Structural characterisation of biominerals and biomimetic crytallisation of calcium carbonate". [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=97572861X.
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21
Laing, Julie Hamilton. "Intracrystalline macromolecules from the shell of the articulated brachiopod, Terebratulina retusa (Linnaeus)". Thesis, University of Glasgow, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310210.
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Al-Mosawi, Mohammed. "Towards a 4-D spatial and temporal model of human enamel biomineralisation". Thesis, Queen Mary, University of London, 2018. http://qmro.qmul.ac.uk/xmlui/handle/123456789/41764.
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Precise timings and spatial progression of human enamel biomineralisation are still largely unknown due to scarcity of developing human enamel specimens available for investigation. This information is crucial for optimising emerging biomimetic regenerative and reparative dentistry routes. Five developing permanent incisors were obtained from an archaeological source and used alongside mature contemporary teeth for comparison. X-ray microtomography (XMT), synchrotron X-ray diffraction (S-XRD) and quantitative back-scattered electrons (qBSE) imaging were used to investigate the mineral density distribution, the crystallites texture magnitude and orientation and the nanostructure of dental enamel at various developmental stages, respectively. XMT revealed that there was a bi-directional mineralisation "front" that starts at the cusp tip and at the enamel-dentine junction (EDJ) travelling cervically and peripherally until the relative mineral density is uniform in the fully mature tooth (2.75 g/cm3 ± 0.01 g/cm3). S-XRD revealed that within one probed region, two populations of crystallite orientations exist simultaneously with an angular separation of 20-50°, with one population being more dominant than the other by a factor of approximately 3:7. Furthermore, one population displayed a higher degree of crystallite texture than the other. These phenomena were observed in all stages of tooth development. The crystallites in both populations were oriented approximately perpendicular to the EDJ regardless of development stage, indicating initial preferred directions of crystallites persist from early through to full maturation. The direction and magnitude of organisation within two distinct populations of crystallites within the developing and mature enamel has not been quantified previously. qBSE analyses suggested that the two observed populations are most likely due to prism decussation and revealed that mineralisation of prism cores precedes that of prism boundaries. These results provide new insights towards building a quantitative spatio-temporal model of human enamel biomineralisation in order to inform emerging biomimetic reparative/regenerative dental technologies.
23
Wieneke, Ralph. "Synthese von Polyaminen und Silaffinen aus Diatomeen und Charakterisierung ihrer Funktion bei der Biomineralisation von Siliziumdioxid /". Marburg : Görich & Weiershäuser, 2009. http://d-nb.info/999158503/04.
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Ustunkaya, Meltem Cemre. "Biological Decay And Its Control By Biomineralisation In Calcareous Stones". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12610259/index.pdf.
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Biodeterioration has an important role in weathering of historical materials. Natural stone materials become vulnerable to physical and chemical changes in outdoor conditions, favouring the biological growth.
In this study, biodeterioration on calcareous stones and its control by biomineralisation were studied on limestones from Nemrut Mount Monument and marbles from Pessinous Archaeological Site. For qualitative and quantitative detection of biological activity fluorescein diacetate (FDA) method that was developed for soil microbial activity was applied to stones of historic monuments. Qualitative FDA analysis was used on cross sections of the samples in order to observe the depth of penetration and effects of biomineralisation using a light microscope with fluorescent light source. Quantitative FDA analysis was done by spectrophotometric determination of fluorescence formed by FDA treatment. X-Ray Diffraction (XRD) analyses were used in determining mineralogical structure of patinas and stone base. Light microscopy was used to investigate changes in morphological structure of historic stone in cross and thin sections of the samples. The control of biodeterioration on stone surfaces was studied by biomineralisation treatments using Bacillus cereus. The results of biomineralisation were evaluated by XRD, light microscopy, SEM-EDX and FDA analyses.
The results of this study showed that the biodeterioration was an important decay factor in stone materials. It started from the surface and penetrated through the microstructure of the stone up to about four cm depth. Biodeterioration also contributed to the growth of microcracks. Results of biomineralisation using B.cereus to form a protective coating on limestone and marble were also discussed.
25
Woodruff, Sarah Louise. "Biomineralisation reactions of algal biofilms at the sediment-water interface". Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368647.
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Monnington, Amy Elizabeth. "Modelling magnetite biomineralisation : the interactions of proteins and Fe3O4 surfaces". Thesis, University of Huddersfield, 2014. http://eprints.hud.ac.uk/id/eprint/23448/.
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The biosynthesis of magnetite is the earliest known example of biomineralisation; how-ever, much of the detailed atomistic mechanisms by which the process occurs are unknown. Within the bacterial strain Magnetospirillum magneticum AMB-1, the formation of mag-netite nanoparticles is thought to occur under the influence of the Mms6 protein. The C–terminal of this protein is highly acidic, containing dense carboxyl and hydroxyl groups, and exhibits direct interaction with the magnetite surface. In this thesis, a novel atomistic model of Mms6-driven magnetite formation was developed and the interactions of amino acids, dipeptide, tetrapeptide and pentapeptide sequences, related to the C-terminus of Mms6, with the{100}and{111}magnetite surfaces (both in vacu and solvated) have been investigated. Each study was split into two systems; a classic molecular dynamics system and a constrained molecular dynamics system utilising the Potential of Mean Force. Initially, the attachment of the individual amino acids to magnetite surfaces was consid-ered. From these results, it was established that the {111} surface was the favoured for surface for amino acid attachment and bonding occurred through octahedral iron ions, rather than tetrahedral iron ions. Furthermore, the charged amino acids demonstrated a higher affinity for iron binding and solvation of unconstrained systems diminished the iron binding abilities of all the amino acids. Secondly, based on a glutamate repeat motif, the attachment of a series of di- and tetrapep-tides to the {100} and {111} magnetite surfaces was explored. It was hypothesised that if the negatively charged glutamate was substituted for a charge neutral alanine, the iron binding potential of the sequence would reduce. The results suggested that the substitu-tion of glutamate for alanine significantly reduces the iron binding affinity of the system on the {100} surface, irrespective of sequence length and composition. However, on the {111}surface, the introduction of alanine differentially modulates the iron binding activity of the sequences investigated. Sequential substitution in a two amino acid chain confers inhibition of iron binding, conversely, in a four amino acid chain, iron binding affinity is enhanced. The final chapter utilised pentapeptides taken from the Cterminal region, thus ensuring the full sequence was explored. The binding behaviour of these pentapeptides and their related mutants, were investigated. It was found that the different sections behaved differ-ently from each other, suggesting that the binding activity of the C-terminal sequence is partly dependent on how the amino acids interact with each other. It was theorised that sequence mutation would decrease iron binding; however, the data suggested that this was not always the case and was sequence dependent. Based on the constrained system data, mutation of the original sequences confirmed the hypothesis for DIESA, LRDAL and EVELR on the {100} surface, and for SRDIE and SDEEV on the {111} surface, whereas, the theory was contradicted for the counterparts surfaces and for both surfaces of ELRDA. This data also suggests that the {111} surface was the preferred surface of attachment, with the exception of LRDAL. For the unconstrained systems, the observations differed dependent on the data analysis technique utilised, as well as on the pentapeptide original sequence, with none of the sequences explored fully confirming the hypothesis. Furthermore, the presence of water in the unconstrained systems was detrimental to the iron binding potential of the pentapeptides. The data from both the unconstrained and constrained systems propose that, there are many factors affecting the iron binding ability other than sequence mutation, such as, surface type, iron type and sequence dependence.
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Fallon, Philip Spencer. "The design, synthesis and applications of hydrogen bonded molecular assemblies". Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388247.
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Harms, Marc. "Prinzipien der Biomineralisation: Morphosynthetische Verfahren zur Kristallisation von Calciumcarbonat unter spezieller Betrachtung von amorphen Festkörperphasen". [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-60558.
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Moseke, Claus. "Biomineralisation von Knochengewebe unter dem Einfluss von Metallionen Modellsyteme und Kristallanalyse /". [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=970193424.
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Durak, Grazyna. "Cellular and molecular mechanisms of biomineralisation in a silicifying haptophyte Prymnesium neolepis". Thesis, University of Plymouth, 2014. http://hdl.handle.net/10026.1/3098.
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Haptophytes are renowned for the most prominent and biogeochemically important group of marine calcifiers: coccolithophores. The unexpected discovery of a unique, silicifying member of this clade - Prymnesium neolepis - prompted questions regarding mechanisms of silicification and their origin in the calcifier-dominated haptophytes. To address these questions I used cell physiology, biochemistry and molecular approaches, investigating cellular and molecular mechanisms involved in silicification in haptophytes. Comparisons of this system with calcification in coccolithophores and other silica-based systems in eukaryotes were also made. Here I report that P. neolepis is an obligate silicifier, producing silica scales in a process fundamentally different to that observed in coccolithophores. Scale deposition and secretion in P. neolepis is localized in the posterior, vacuolar part of the cell rather than in the anterior part near the flagellar roots as in calcifying coccolithophores. The organic matrix underlying silica scales in P. neolepis was found to be non-homologous with organic scales, which in coccolithophores serve as coccolith baseplates. This suggests, that silica scales and coccoliths arise from two distinct, most likely non-homologous processes, which is further supported by the comparative investigation of the role of cytoskeleton in silica scale production in P. neolepis and coccolithogenesis in a representative calcifier, Coccolithus pelagicus. Using cytoskeleton inhibitors I established, that the cytoskeleton components used for morphogenesis and secretion of biomineralised structures are different in these two systems. Analysis of P. neolepis biosilica revealed the presence of an intimately associated organic fraction consisting of a putatively chitin-containing material, potentially serving as an organic matrix underlying silica scales. Further biochemical investigation of the biosilica-associated organics confirmed the presence of long chain polyamines (LCPAs) dissimilar to those previously reported in diatoms and sponges. Additionally, a potentially novel, proline and lysine-rich protein sharing a weak homology with lipocalins was recovered, suggesting that this silicification system is unique to haptophytes. Several theories concerning acquisition of the ability to silicify in haptophytes were proposed. Overall, the findings presented in this study provide a detailed description of Si biomineralisation system in this unique, silicifying haptophyte and supply novel information on biomineralisation systems in marine haptophytes. This study contributes a basis on which the phenomenon of silicification in haptophytes can be further investigated, as well as novel information which can be further used in elucidation of origins of silicification in algae and other Eucarya.
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Gröger, Christian. "Solid-state NMR spectroscopic studies concerning the biomineralization process in diatoms and on inorganic phosphorus chalcogenide cage compounds". kostenfrei, 2008. http://www.opus-bayern.de/uni-regensburg/volltexte/2008/977/.
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au, jeremy shaw@uwa edu, i Jeremy Shaw. "Biomineralisation processes in the radula teeth of the chiton Acanthopleura hirtosa (Mollusca: Polyplacophora)". Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20080703.163505.
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A detailed row by row investigation of major lateral tooth cusp mineralisation, together with the concomitant development of the superior epithelial tissue surrounding the teeth of the chiton Acanthopleura hirtosa has been undertaken using a combination of light microscopy, and scanning and transmission electron microscopy. A holistic approach has been adopted that encompasses observations over a range of spatial scales, from whole radula mineralisation processes to those occurring within individual tooth cusps at various stages of development. In addition, mineralisation in radulae from freshly collected animals has been compared to that of animals maintained for extensive periods within a newly developed iron limited system, which restricts radula mineralisation without impeding the formation of the organic matrix.
An evaluation of the iron limitation technique has revealed that maintaining specimens of A. hirtosa within an iron poor environment results in a significant departure from the normal pattern of mineralisation in these animals. As a consequence of iron limitation, there is an obvious increase in the number of unmineralised tooth rows in addition to associated alterations in structure and composition at all stages of tooth development.
In normal specimens of A. hirtosa, the onset of mineralisation in the tooth cusps occurs following the prior accumulation of iron at the junction zone and the sudden accumulation of iron containing granules in the cusp epithelium at tooth row 13. The superior epithelium surrounding the tooth cusps undergoes a series of developmental changes leading up to, and following, the onset of mineralisation. In particular, the abundance of mitochondria within the apical cusp epithelium increases, presumably in order to provide the ideal conditions of pH, and thus solubility, needed for the supersaturation of iron and its nucleation at row 13. Once mineralisation has commenced, the microvilli attached to the cusps develop rapidly, and are suggested to do so in order to facilitate the transport of iron, and thereby ensure that a high concentration gradient of this element into the cusps is maintained.
The delivery of iron into the cusps occurs from two fronts, the first from the superior epithelium via the posterior surface, and the second from the junction zone via an internal pathway situated along the lepidocrocite boundary between the magnetite and core regions of the tooth. The existence of a plume of elements between this internal mineralisation pathway and the junction zone, provides the first direct evidence that the junction zone is involved in the storage and release of elements for cusp mineralisation. Data from iron limited radulae also indicate that iron continues to be deposited at the junction zone in preference to the superior epithelium or cusps, despite the disruption of mineralisation, highlighting the importance of this region in the mineralisation process.
Iron reinstatement experiments have also shown that the internal pathways of iron delivery within the organic matrix remain viable, despite prolonged periods of iron limitation. In addition, the reinstatement of iron has revealed that the plumes, situated between the junction zone and internal mineralising pathway of the cusp, stem from the centre of the plate like junction zone, directly above the stylus canal, a tube like cavity situated within the styli of each major lateral tooth.
An in depth study of the stylus canal has revealed that cells within the canal are remarkably similar to those of the epithelium surrounding the cusps, suggesting that this structure may also be involved in the delivery of ions to the junction zone. The stylus canal is shown to be present in the major lateral tooth cusps of 38 chiton species distributed worldwide, and is therefore likely to be a feature common to all chitons. The presence of the canal, and indeed its absence from the bases of all remaining non iron mineralised teeth, irrespective of chiton species, also points strongly to a functional relationship between the stylus canal and tooth cusp mineralisation.
33
Melcher, Melanie [Verfasser], i Bernhard [Akademischer Betreuer] Hauer. "Charakterisierung von Proteinen für die Biomineralisation von Hydroxylapatit / Melanie Melcher. Betreuer: Bernhard Hauer". Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2015. http://d-nb.info/1078898758/34.
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Shaw, Jeremy Albert. "Biomineralisation processes in the radula teeth of the chiton Acanthopleura hirtosa (Mollusca: Polyplacophora) /". Access via Murdoch University Digital Theses Project, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20080703.163505.
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Shaw, Jeremy. "Biomineralisation processes in the radula teeth of the chiton Acanthopleura hirtosa (Mollusca: Polyplacophora)". Thesis, Shaw, Jeremy (2007) Biomineralisation processes in the radula teeth of the chiton Acanthopleura hirtosa (Mollusca: Polyplacophora). PhD thesis, Murdoch University, 2007. https://researchrepository.murdoch.edu.au/id/eprint/306/.
Pełny tekst źródłaStreszczenie:
A detailed row by row investigation of major lateral tooth cusp mineralisation, together with the concomitant development of the superior epithelial tissue surrounding the teeth of the chiton Acanthopleura hirtosa has been undertaken using a combination of light microscopy, and scanning and transmission electron microscopy. A holistic approach has been adopted that encompasses observations over a range of spatial scales, from whole radula mineralisation processes to those occurring within individual tooth cusps at various stages of development. In addition, mineralisation in radulae from freshly collected animals has been compared to that of animals maintained for extensive periods within a newly developed iron limited system, which restricts radula mineralisation without impeding the formation of the organic matrix.
An evaluation of the iron limitation technique has revealed that maintaining specimens of A. hirtosa within an iron poor environment results in a significant departure from the normal pattern of mineralisation in these animals. As a consequence of iron limitation, there is an obvious increase in the number of unmineralised tooth rows in addition to associated alterations in structure and composition at all stages of tooth development.
In normal specimens of A. hirtosa, the onset of mineralisation in the tooth cusps occurs following the prior accumulation of iron at the junction zone and the sudden accumulation of iron containing granules in the cusp epithelium at tooth row 13. The superior epithelium surrounding the tooth cusps undergoes a series of developmental changes leading up to, and following, the onset of mineralisation. In particular, the abundance of mitochondria within the apical cusp epithelium increases, presumably in order to provide the ideal conditions of pH, and thus solubility, needed for the supersaturation of iron and its nucleation at row 13. Once mineralisation has commenced, the microvilli attached to the cusps develop rapidly, and are suggested to do so in order to facilitate the transport of iron, and thereby ensure that a high concentration gradient of this element into the cusps is maintained.
The delivery of iron into the cusps occurs from two fronts, the first from the superior epithelium via the posterior surface, and the second from the junction zone via an internal pathway situated along the lepidocrocite boundary between the magnetite and core regions of the tooth. The existence of a plume of elements between this internal mineralisation pathway and the junction zone, provides the first direct evidence that the junction zone is involved in the storage and release of elements for cusp mineralisation. Data from iron limited radulae also indicate that iron continues to be deposited at the junction zone in preference to the superior epithelium or cusps, despite the disruption of mineralisation, highlighting the importance of this region in the mineralisation process.
Iron reinstatement experiments have also shown that the internal pathways of iron delivery within the organic matrix remain viable, despite prolonged periods of iron limitation. In addition, the reinstatement of iron has revealed that the plumes, situated between the junction zone and internal mineralising pathway of the cusp, stem from the centre of the plate like junction zone, directly above the stylus canal, a tube like cavity situated within the styli of each major lateral tooth.
An in depth study of the stylus canal has revealed that cells within the canal are remarkably similar to those of the epithelium surrounding the cusps, suggesting that this structure may also be involved in the delivery of ions to the junction zone. The stylus canal is shown to be present in the major lateral tooth cusps of 38 chiton species distributed worldwide, and is therefore likely to be a feature common to all chitons. The presence of the canal, and indeed its absence from the bases of all remaining non iron mineralised teeth, irrespective of chiton species, also points strongly to a functional relationship between the stylus canal and tooth cusp mineralisation.
36
Shaw, Jeremy. "Biomineralisation processes in the radula teeth of the chiton Acanthopleura hirtosa (Mollusca: Polyplacophora)". Shaw, Jeremy (2007) Biomineralisation processes in the radula teeth of the chiton Acanthopleura hirtosa (Mollusca: Polyplacophora). PhD thesis, Murdoch University, 2007. http://researchrepository.murdoch.edu.au/306/.
Pełny tekst źródłaStreszczenie:
A detailed row by row investigation of major lateral tooth cusp mineralisation, together with the concomitant development of the superior epithelial tissue surrounding the teeth of the chiton Acanthopleura hirtosa has been undertaken using a combination of light microscopy, and scanning and transmission electron microscopy. A holistic approach has been adopted that encompasses observations over a range of spatial scales, from whole radula mineralisation processes to those occurring within individual tooth cusps at various stages of development. In addition, mineralisation in radulae from freshly collected animals has been compared to that of animals maintained for extensive periods within a newly developed iron limited system, which restricts radula mineralisation without impeding the formation of the organic matrix.
An evaluation of the iron limitation technique has revealed that maintaining specimens of A. hirtosa within an iron poor environment results in a significant departure from the normal pattern of mineralisation in these animals. As a consequence of iron limitation, there is an obvious increase in the number of unmineralised tooth rows in addition to associated alterations in structure and composition at all stages of tooth development.
In normal specimens of A. hirtosa, the onset of mineralisation in the tooth cusps occurs following the prior accumulation of iron at the junction zone and the sudden accumulation of iron containing granules in the cusp epithelium at tooth row 13. The superior epithelium surrounding the tooth cusps undergoes a series of developmental changes leading up to, and following, the onset of mineralisation. In particular, the abundance of mitochondria within the apical cusp epithelium increases, presumably in order to provide the ideal conditions of pH, and thus solubility, needed for the supersaturation of iron and its nucleation at row 13. Once mineralisation has commenced, the microvilli attached to the cusps develop rapidly, and are suggested to do so in order to facilitate the transport of iron, and thereby ensure that a high concentration gradient of this element into the cusps is maintained.
The delivery of iron into the cusps occurs from two fronts, the first from the superior epithelium via the posterior surface, and the second from the junction zone via an internal pathway situated along the lepidocrocite boundary between the magnetite and core regions of the tooth. The existence of a plume of elements between this internal mineralisation pathway and the junction zone, provides the first direct evidence that the junction zone is involved in the storage and release of elements for cusp mineralisation. Data from iron limited radulae also indicate that iron continues to be deposited at the junction zone in preference to the superior epithelium or cusps, despite the disruption of mineralisation, highlighting the importance of this region in the mineralisation process.
Iron reinstatement experiments have also shown that the internal pathways of iron delivery within the organic matrix remain viable, despite prolonged periods of iron limitation. In addition, the reinstatement of iron has revealed that the plumes, situated between the junction zone and internal mineralising pathway of the cusp, stem from the centre of the plate like junction zone, directly above the stylus canal, a tube like cavity situated within the styli of each major lateral tooth.
An in depth study of the stylus canal has revealed that cells within the canal are remarkably similar to those of the epithelium surrounding the cusps, suggesting that this structure may also be involved in the delivery of ions to the junction zone. The stylus canal is shown to be present in the major lateral tooth cusps of 38 chiton species distributed worldwide, and is therefore likely to be a feature common to all chitons. The presence of the canal, and indeed its absence from the bases of all remaining non iron mineralised teeth, irrespective of chiton species, also points strongly to a functional relationship between the stylus canal and tooth cusp mineralisation.
37
Kufelt, Olga [Verfasser]. "Polymer-Silica-Materialien : ihre Bedeutung bei der Biomineralisation und in der Biomaterialforschung / Olga Kufelt". Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover, 2010. http://d-nb.info/1010840533/34.
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Telesca, Luca. "Environmental change impacts on marine calcifiers : spatial and temporal biomineralisation patterns in mytilid bivalves". Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/289445.
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Environmental change is a major threat to marine ecosystems worldwide. Understanding the key biological processes and environmental factors mediating spatial and temporal species' responses to habitat alterations underpins our ability to forecast impacts on marine ecosystems under any range of scenarios. This is especially important for calcifying species, many of which have both a high climate sensitivity and disproportionately strong ecological impacts in shaping marine communities. Although geographic patterns of calcifiers' sensitivity to environmental changes are defined by interacting multiple abiotic and biotic stressors, local adaptation, and acclimation, knowledge on species' responses to disturbance is derived largely from short- and medium-term laboratory and field experiments. Therefore, little is known about the biological mechanisms and key drivers in natural environments that shape regional differences and long-term variations in species vulnerability to global changes. In this thesis, I examined natural variations in shell characteristics, both morphology and biomineralisation, under heterogeneous environmental conditions i) across large geographical scales, spanning a 30° latitudinal range (3,334 km), and ii) over historical times, using museum collections (archival specimens from 1904 to 2016 at a single location), in mussels of the genus Mytilus. The aim was to observe whether plasticity in calcareous shell morphology, production, and composition mediates spatial and temporal patterns of resistance to climate change in these critical foundation species. For the morphological analyses, the combined use of new statistical methods and multiple study systems at various geographical scales allowed the uncoupling of the contribution of development, genetic status, and environmental factors to shell morphology. I found salinity had the strongest effect on the latitudinal patterns of Mytilus shape. Temperature and food supply, however, were the main predictor of mussel shape heterogeneity. My results suggest the potential of shell shape plasticity in Mytilus as a powerful indicator of rapid environmental changes. I found decreasing shell calcification towards high latitudes. Salinity was the best predictor of regional differences in shell deposition, and its mineral and organic composition. In polar, low-salinity environments, the production of calcite and organic shell layers was increased, while aragonite deposition was enhanced under temperate, higher-salinity regimes. Interacting strong effects of decreasing salinity and increasing food availability on compositional shell plasticity predict the deposition of a thicker external organic layer (periostracum) at high latitudes under forecasted future conditions. This response potential of Mytilus shell suggests an enhanced protection of temperate mussels from predators and a strong capacity for increased resistance of polar and subpolar individuals to dissolving water conditions. Analyses of museum specimens indicated increasing shell calcification during the last century. Deposition of individual shell layers was more closely related to temporal changes in the variability of key environmental drivers than to alterations of mean habitat conditions. Calcitic layer and periostracum showed marked responses to alterations of biotic conditions, suggesting the potential of mussels to trade-off between the deposition of calcareous and organic layers as a compensatory response to strategy-specific predation pressure. These changes in biomineralisation indicated a marked resistance to environmental change over the last century in a species predicted to be vulnerable, and how locally heterogeneous environments and predation levels can have a stronger effect on Mytilus responses than global environmental trends. My work illustrates that biological mechanisms and local conditions, driving plastic responses to the spatial and temporal structure of multiple abiotic and biotic stressors, can define geographic and temporal patterns of unforeseen species resistance to global environmental change.
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Kammer, Martin [Verfasser], Eike [Akademischer Betreuer] Brunner i Thomas [Akademischer Betreuer] Wolff. "Schwingungsspektroskopische Untersuchungen zur Biomineralisation / Martin Kammer. Gutachter: Eike Brunner ; Thomas Wolff. Betreuer: Eike Brunner". Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://d-nb.info/106844343X/34.
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Tourney, Janette. "The role of bacterial extracellular polymers in cell surface chemistry, metal adsorption and biomineralisation". Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/14561.
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This study aimed to characterise the role of bacterial extracellular polymers in surface reactivity, metal adsorption and biomineralisation. This was undertaken using an EPS-producing, thermophilic, bacterial strain, Bacillus licheniformis S-86. Experimental work was undertaken comparing cells with the EPS layer intact (native cells) with cells from which the EPS layer had been extracted (EPS-free cells). The study incorporated surface characterisation by potentiometric titration, infrared analysis and electrophoretic mobility analysis. Investigation of the mechanisms of zinc and nickel adsorption to cell surfaces was undertaken by both macroscopic batch adsorption experiments, and spectroscopic (EXAFS) analysis. Surface complexation modelling of the potentiometric titration data indicated that the native and EPS-free cells contained four proton-active functional groups, with pKa values of 3.3-3.4, 5.3-5.4, 7.4-7.5 and 9.9-10.1. These were tentatively identified as phosphodiester, carboxyl, phosphoryl and hydroxyl/amine groups respectively, and ATR-FTIR analysis supported identification of the pKa 5.3-5.4 site as carboxylic. The site concentrations of the pKa 3.3-3.4 and 9.9-10.1 groups were significantly lower in the EPS-free cells than in the native cells. Both the macroscopic and EXAFS metal adsorption studies indicated that the carboxyl group is of principle importance to Zn complexation, and a lack of temperature-dependent adsorption provides evidence that Zn binds by an outer-sphere mechanism. Results for Ni did not provide a conclusive explanation of the binding mechanism. Biomineralisation experiments indicated that the presence of EPS affects both CaCO3 morphology and polymorphism. The metastable polymorph vaterite appears less stable in the presence of EPS. The results of this study have shown that EPS, and potentially the associated dissolved organic carbon, can significantly affect the surface reactivity of bacterial cells.
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Henkes, Thorsten Matthias [Verfasser], i Bernhard [Akademischer Betreuer] Hauer. "Peptide und Fusionsproteine für die Biomineralisation von Hydroxylapatit / Thorsten Matthias Henkes ; Betreuer: Bernhard Hauer". Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2021. http://d-nb.info/1240232993/34.
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Li, Yang. "Octacalcium phosphate-metabolite composites : model compounds for bone mineral structure". Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/274877.
Pełny tekst źródłaStreszczenie:
Bone turnover has important impacts on bone health. The process modifies weak primary woven bone into the strong lamellar bone, repairs damage in bone, and maintains appropriate calcium homeostasis. The process relies heavily on controlled osteoclastic resorption by dissolution of mineral in the area undergoing remodelling. Bone degenerative diseases occur when the balance between bone resorption and deposition of new bone in the turnover process is altered. Bone is a nanocomposite material composed of a mineral phase (calcium phosphate) deposited within an organic matrix. In spite of the intensive research on the subject, the precise molecular structure of the bone mineral is still an open question. The incorporation of citrate within the mineral structure introduced by Davies et al has provide a more comprehensive structural model that could explain many observations in terms of the mineral structure. Based on this new structural model, a hypothesis has been proposed: that other metabolites similar to citrate can be incorporated into the mineral structure, and differences in metabolite incorporation cause fundamental differences in the physical properties of bone mineral. Thus understanding the effect of metabolite incorporation on the physical properties of bone mineral will lead to insight into the molecular mechanisms of bone degenerative diseases and provide a link between bone quality and bone cell function that is currently missing. Chapter 1 provides overview of the bone composite and formation, and changes in its properties during ageing. The development of the mineral structural model is described and the shortcoming of existing models are assessed. Chapter 2 introduces the theoretical foundations of solid-state NMR spectroscopy, which is the primary analytical method employed in this study, followed by specific experimental techniques that have been used in this work. Chapter 3 described the characterisation of seven different OCP-metabolite composites that have been synthesized in this work, and proposes possible structural model for these composites based on an NMR crystallography approach to determine a structural model for one of the synthetic OCP-metabolite compounds, OCP-SUC. In Chapter 4, the dissolution rate of OCP-metabolites is measured in acidic solution to mimic the resorption process by osteoclasts and assess the possible effects of different incorporated metabolites on the solubility of bone mineral. Finally, Chapter 5 summarises the conclusions from the work and suggests the next steps that arise from this work to uncover the complete molecular structure of bone mineral and its variability in disease.
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Cordes, Petra. "Streng biomimetische Modellsysteme für die Biomineralisation von Siliciumdioxid auf der Basis von Polyaminen oder Alkylglycosiden". [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981625312.
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Harms, Marc. "Prinzipien der Biomineralisation morphosynthetische Verfahren zur Kristallisation von Calciumcarbonat unter spezieller Betrachtung von amorphen Festkörperphasen". Saarbrücken VDM Verlag Dr. Müller, 2006. http://d-nb.info/988960249/04.
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Harms, Marc. "Prinzipien der Biomineralisation : morphosynthetische Verfahren zur Kristallisation von Calciumcarbonat unter spezieller Betrachtung von amorphen Festkörperphasen /". Saarbrücken : VDM Verlag Dr. Müller, 2008. http://d-nb.info/988960249/04.
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Hufton, Joseph. "The role of the bacterial cell surface and extracellular macromolecules in U(VI) biosorption and biomineralisation". Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/13628/.
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Uranium biosorption and biomineralisation are processes exhibited by bacteria that aren’t fully understood at a mechanistic level, making it difficult to consider their use and application in remediation, extraction and reuse. The aim of this study was, therefore, to deconstruct the bacterial cell and characterise the specific roles of cell surface structures and extra polymeric substances, in order to elucidate their contribution to the biosorption and biomineralisation of uranium within live cells. The complexation and precipitation of uranium with extracellular DNA (eDNA) was predominantly mediated by negatively charged phosphate moieties within eDNA. The reaction was dependent on pH, where the formation of a precipitate was reduced as the pH increased. Towards circumneutral pH, acid phosphatase liberated phosphate from eDNA that precipitated uranium as a phosphate-bearing mineral. The biosorption of uranium with bacteria is governed by the interactions with functional groups at the cell surface. The cell wall isolates and lysed cells of B. subtilis 168 exhibited a greater uranium retention capacity in comparison to those from P. putida 33015, live cells and cell membrane isolates from both strains. Carboxyl groups and phosphate groups, from proteins and phosphorylated biopolymers, were responsible uranium biosorption with the cell surface structures. The viability and metabolic activity of live cells of P. putida 33015 and D. radiodurans R1 in the presence of uranium was evaluated. An increase in uranium concentration was directly linked to cell toxicity in both strains. At low concentrations of U(VI) and circumneutral pH, viable cells likely sequestered uranium either through biosorption or through the precipitation of enzymatically generated uranium phosphate minerals that were tethered to the cell surface or within EPS as a tolerance mechanism to cope with uranium toxicity. At higher concentrations of uranium or at low pH where the bacterial growth wasn’t favourable or there was cell death, biosorption to the bacterial biomass present likely occurred.
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Gröger, Philip. "Establishing super-resolution imaging of biosilica-embedded proteins in diatoms". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-227150.
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Kieselalgen – auch Diatomeen genannt – verfügen über die einzigartige Fähigkeit, nanostrukturierte, hierarchisch aufgebaute Zellwände aus Siliziumdioxid – auch als Biosilica bekannt – mit beispielloser Genauigkeit und Reproduzierbarkeit zu bilden. Ein tieferes Verständnis für diesen Prozess, der als “Biomineralisation“ bekannt ist, ist nicht nur auf dem Gebiet der Grundlagenforschung zu Kieselalgen sehr bedeutsam, sondern auch für die Nutzung dieser Nanostrukturierung in den Materialwissenschaften oder der Nanobiotechnologie. Nach dem derzeitigem Stand der Wissenschaft wird diese Strukturierung durch die Selbstorganisation von Proteinmustern, an denen sich das Siliziumdioxid bildet, erreicht. Um die Funktion und das Zusammenspiel einzelner Proteine, die an diesem Biomineralisationsprozess beteiligt sind, entschlüsseln zu können, ist es essentiell ihre strukturelle Organisation aufzuklären und diese mit den morphologischen Zellwandmerkmalen zu korrelieren. Die Größenordnung dieser Merkmale ist im Bereich von Nanometern angesiedelt. Mit Hilfe der Elektronenmikroskopie können diese Biosilicastrukturen aufgelöst werden, jedoch ist keine proteinspezifische Information verfügbar. Ziel dieser Arbeit war es daher, eine Technik zu etablieren, die in der Lage ist, einzelne Biosilica-assozierte Proteine mit Nanometer-Präzision zu lokalisieren. Um dieses Ziel zu erreichen, wurde Einzelmoleküllokalisationsmikroskopie (single-molecule localization microscopy, kurz: SMLM) beispielhaft in der Kieselalge Thalassiosira pseudonana etabliert. Die Position verschiedener Biosilica-assoziierte Proteine innerhalb des Biosilicas und nach dessen chemischer Auflösung wurde mit einer hohen räumlichen Auflösung bestimmt. Um quantitative Ergebnisse zu erhalten, wurde ein Analyse-Workflow entwickelt, der grafische Benutzeroberflächen und Skripte für die Visualisierung, das Clustering und die Kolokalisation von SMLM Daten beinhaltet. Um optimale Markierungen für SMLM an Biosilica-eingebetteten Proteinen zu finden, wurde ein umfassendes Screening von photo-schaltbaren fluoreszierenden Proteinen durchgeführt. Diese wurden als Fusionsproteine mit Silaffin3, einem Protein, welches eng mit der Biosilica-Zellwand assoziiert ist, exprimiert. Es konnte gezeigt werden, dass nur drei von sechs Kandidaten funktional sind, wenn sie in Biosilica eingebettet sind. Silaffin3 konnte indirekt mittels SMLM mit einer Lokalisationsgenauigkeit von 25 nm detektiert werden. Dies erlaubte es, seine strukturelle Organisation aufzulösen und Silaffin3 als eine Hauptkomponente in der Basalkammer der Fultoportulae zu identifizierenDiatoms feature the unique ability to form nanopatterned hierarchical silica cell walls with unprecedented accuracy and reproducibility. Gathering a deeper understanding of this process that is known as “biomineralization” is vitally important not only in the field of diatom research. In fact, the nanopatterning can also be exploited in the fields of material sciences or nanobiotechnology. According to the current understanding, the self-assembly of protein patterns along which biosilica is formed is key to this nanopatterning. Thus, in order to unravel the function of individual proteins that are involved in this biomineralization process, their structural organization has to be deciphered and correlated to morphological cell wall features that are in the order of tens of nanometer. Electron microscopy is able to resolve these features but does not provide protein-specific information. Therefore, a technique has to be established that is able to localize individual biosilica-associated proteins with nanometer precision. To achieve this objective, single-molecule localization microscopy (SMLM) for the diatom Thalassiosira pseudonana has been pioneered and exploited to localize different biosilica associated proteins inside silica and after silica removal. To obtain quantitative data, an analysis workflow was developed including graphical user interfaces and scripts for SMLM visualization, clustering, and co-localization. In order to find optimal labels for SMLM to target biosilica-embedded proteins, a comprehensive screening of photo-controllable fluorescent proteins has been carried out. Only three of six candidates were functional when embedded inside biosilica and fused to Silaffin3 – a protein that is tightly associated with the biosilica cell wall. Silaffin3 could be localized using SMLM with a localization precision of 25 nm. This allowed to resolve its structural organization and therefore identified Silaffin3 as a major component in the basal chamber of the fultoportulae. Additionally, co-localization studies on cingulins – a protein family hypothesized to be involved in silica formation – have been performed to decipher their pattern-function relationship. Towards this end, novel imaging strategies, co-localization calculations and pattern quantifications have been established. With the help of these results, the spatial arrangement of cingulins W2 and Y2 could be compared with unprecedented resolution. In summary, this work has laid ground for quantitative SMLM studies of proteins in diatoms in general and contributed insights into the spatial organization of proteins involved in biomineralization in the diatom T. pseudonana
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Peytcheva, Anna. "Kolloidales Calciumphosphat mit polymeren Additiven Struktur und Dynamik /". Phd thesis, [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961883499.
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Gautret, Pascale. "Recherche sur les modalites de la biomineralisation carbonatee chez les demosponges actuelles et fossiles. Implications phylogenetiques et paleobiologiques". Paris 11, 1990. http://www.theses.fr/1990PA112085.
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La classification des spongiaires fossiles a subi de tres profondes transformations apres la decouverte de demosponges actuelles produisant a la fois des spicules siliceux et un squelette calcifie. Ces especes calcifiees actuelles fournissent la possibilite d'etablir un systeme de classification, valable egalement pour les fossiles. L'etude des differents types de biomineralisation carbonatee realisee chez les especes reliques, par l'analyse des dispositions microstructurales de leurs phases minerales, et par l'analyse biochimique de leurs phases organiques associees, permet d'etablir une bonne correlation entre les caracteristiques du squelette calcaire et les autres caracteres biologiques, justifiant l'utilisation taxonomique des criteres microstructuraux. L'identite de certains processus de biomineralisation chez des formes anciennes du paleozoique ou du mesozoique, et des formes actuelles a egalement ete demontree, renouvelant completement les schemas classiques de l'evolution des demosponges depuis des periodes tres anciennes. Il s'avere en outre que les processus de biomineralisation developpes par ces spongiaires sont fortement influences par les conditions oceanologiques: lorsque celles-ci sont defavorables, certaines lignees cessent de produire des structures carbonatees et se trouvent absentes de la documentation fossile. Elles y reapparaissent, strictement identiques, des que ces conditions se modifient a nouveau
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Wrede, Christoph [Verfasser], Michael [Akademischer Betreuer] Hoppert, Jörg [Akademischer Betreuer] Stülke i Joachim [Akademischer Betreuer] Reitner. "Metabolismus und Biomineralisation in anaerob Methan-oxidierenden Lebensgemeinschaften / Christoph Wrede. Gutachter: Michael Hoppert ; Jörg Stülke ; Joachim Reitner. Betreuer: Michael Hoppert". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2011. http://d-nb.info/1042640122/34.
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