Apatite Formation Abilities and Mechanical Properties of Hydroxyethylmethacrylate-based Organic-inorganic Hybrids Incorporated with Sulfonic Groups and Calcium Ions

Apatite formation in the living body is an essential requirement for artificial materials to exhibit bone-bonding bioactivity. It has been recently revealed that sulfonic groups trigger apatite nucleation in a body environment. Organic–inorganic hybrids consisting of organic polymers and the sulfonic groups are therefore expected to be useful for preparation of novel bone-repairing materials exhibiting flexibility as well as bioactivity. In the present study, organic–inorganic hybrids were prepared from hydroxyethylmethacrylate (HEMA) in the presence of vinylsulfonic acid sodium salt (VSAS) and calcium chloride (CaCl2). The bioactivities of the hybrids were assessed in vitro by examining the apatite formation in simulated body fluid (SBF, Kokubo solution). The hybrids deposited on the apatite after soaking in SBF within 7 days. Tensile strength measurements showed a tendency to increase with increases in VSAS and CaCl2 content. It was assumed that this phenomenon was attributed to the formation of cross-linking in the hybrids

Apatite Formation Abilities and Mechanical Properties of Hydroxyethylmethacrylate-based Organic-inorganic Hybrids Incorporated with Sulfonic Groups and Calcium Ions

Apatite formation in the living body is an essential requirement for artificial materials to exhibit bone-bonding bioactivity. It has been recently revealed that sulfonic groups trigger apatite nucleation in a body environment. Organic–inorganic hybrids consisting of organic polymers and the sulfonic groups are therefore expected to be useful for preparation of novel bone-repairing materials exhibiting flexibility as well as bioactivity. In the present study, organic–inorganic hybrids were prepared from hydroxyethylmethacrylate (HEMA) in the presence of vinylsulfonic acid sodium salt (VSAS) and calcium chloride (CaCl2). The bioactivities of the hybrids were assessed in vitro by examining the apatite formation in simulated body fluid (SBF, Kokubo solution). The hybrids deposited on the apatite after soaking in SBF within 7 days. Tensile strength measurements showed a tendency to increase with increases in VSAS and CaCl2 content. It was assumed that this phenomenon was attributed to the formation of cross-linking in the hybrids

Structural Study of Binary Phosphate Glasses by X-ray and Neutron Diffraction

X-ray and neutron diffraction study on the structure of five binary metaphosphate glasses has been made by applying the pair function method coupled with the interference function refining technique. The distances and coordination numbers for the pairs of P-O, O-O and M-O (M=Li, Na, Zn, Mg, and Ca) were determined and a fundamental local ordering unit structure in these binary phosphate glasses has been confirmed to be a PO_4 tetrahedron and the particular features have also been recognized with respect to the numbers of oxygens around magnesium and zinc cations

Fabrication of Mullite Body Using Superplastic Transient Phase

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65799/1/j.1151-2916.1992.tb05542.x.pd

The Dangers of Decoupling: Earth System Crisis and the 'Fourth Industrial Revolution'

The question of whether global capitalism can resolve the earth system crisis rests on the (im)possibility of ‘absolute decoupling’: whether or not economic growth can continue indefinitely as total environmental impacts shrink. Ecomodernists and other techno‐optimists argue for the feasibility of absolute decoupling, whereas degrowth advocates show that it is likely to be neither feasible in principle nor in the timeframe needed to ward off ecological tipping points. While primarily supporting the degrowth perspective, I will suggest that the ecomodernists have a wildcard in their pocket that hasn’t been systematically addressed by degrowth advocates. This is the ‘Fourth Industrial Revolution’, which refers to convergent innovations in biotechnology, nanotechnology, artificial intelligence, 3D printing, and other developments. However, I will argue that while these innovations may enable some degree of absolute decoupling, they will also intensify emerging risks in the domains of biosecurity, cybersecurity, and state securitization. Overall, these technologies will not only place unprecedented destructive power in the hands of non‐state actors but will also empower and incentivize states to create a global security regime with unprecedented surveillance and force mobilization capacities. This reinforces the conclusion that mainstream environmental policies based on decoupling should be reconsidered and supplanted by alternative policy trajectories based on material‐energetic degrowth, redistribution, and technological deceleration

Signal One and Two Blockade Are Both Critical for Non-Myeloablative Murine HSCT across a Major Histocompatibility Complex Barrier

Non-myeloablative allogeneic haematopoietic stem cell transplantation (HSCT) is rarely achievable clinically, except where donor cells have selective advantages. Murine non-myeloablative conditioning regimens have limited clinical success, partly through use of clinically unachievable cell doses or strain combinations permitting allograft acceptance using immunosuppression alone. We found that reducing busulfan conditioning in murine syngeneic HSCT, increases bone marrow (BM):blood SDF-1 ratio and total donor cells homing to BM, but reduces the proportion of donor cells engrafting. Despite this, syngeneic engraftment is achievable with non-myeloablative busulfan (25 mg/kg) and higher cell doses induce increased chimerism. Therefore we investigated regimens promoting initial donor cell engraftment in the major histocompatibility complex barrier mismatched CBA to C57BL/6 allo-transplant model. This requires full myeloablation and immunosuppression with non-depleting anti-CD4/CD8 blocking antibodies to achieve engraftment of low cell doses, and rejects with reduced intensity conditioning (≤75 mg/kg busulfan). We compared increased antibody treatment, G-CSF, niche disruption and high cell dose, using reduced intensity busulfan and CD4/8 blockade in this model. Most treatments increased initial donor engraftment, but only addition of co-stimulatory blockade permitted long-term engraftment with reduced intensity or non-myeloablative conditioning, suggesting that signal 1 and 2 T-cell blockade is more important than early BM niche engraftment for transplant success

In-process truing of metal-bonded grinding wheels by pulse width control in ELID grinding

LEM 2005 - 3rd International Conference on Leading Edge Manufacturing in 21st Century709-71