Effect of pH and temperature on the morphology and phases of co-precipitated hydroxyapatite

This paper reports a high-yield process to fabricate biomimetic hydroxyapatite nano-particles or nano-plates. Hydroxyapatite is obtained by simultaneous dripping of calcium chloride and ammonium hydrogen phosphate solutions into a reaction vessel. Reactions were carried out under various pH and temperature conditions. The morphology and phase composition of the precipitates were investigated using scanning electron microscope and X-ray diffraction. The analyses showed that large plates of calcium hydrophosphate are formed at neutral or acidic pH condition. Nanoparticles of hydroxyapatite were obtained in precipitates prepared at pH 9–11. Hydroxyapatite plates akin to seashell nacre were obtained at 40 °C and pH 9. This material holds promise to improve the strength of hydroxyapatite containing composites for bone implant or bone cement used in orthopaedic surgeries. The thermodynamics of the crystal growth under these conditions was discussed. An assembly mechanism of the hydroxyapatite plates was proposed according to the nanostructure observations

Wall Crossing and Instantons in Compactified Gauge Theory

We calculate the leading weak-coupling instanton contribution to the moduli-space metric of N=2 supersymmetric Yang-Mills theory with gauge group SU(2) compactified on R^3 x S^1. The results are in precise agreement with the semiclassical expansion of the exact metric recently conjectured by Gaiotto, Moore and Neitzke based on considerations related to wall-crossing in the corresponding four-dimensional theory.Comment: 24 pages, no figure

Ambulatory intraocular pressure fluctuation recording with a novel wireless smart silicone contact lens sensor

The Conference program's website is located at http://apacrs2014.org/free_papers.htmlSession - FP1: General: no. FP1-03INTRODUCTION: Monitoring of treatment response in the management of glaucomatous optic neuropathy relies on single intraocular pressure (IOP) measurements during regular clinic hours at regular intervals. However IOP is a dynamic parameter with circadian rhythms as well as posture and exercise related fluctuations. The introduction of continuous 24 hour IOP monitoring technology has created a paradigm shift in glaucoma management. Our wireless smart contact lens sensor was previously validated in-vivo and ex-vivo in animal models. Here we describe the performance of the sensor in ...postprin

Holography For a De Sitter-Esque Geometry

Warped dS$_3$ arises as a solution to topologically massive gravity (TMG) with positive cosmological constant $+1/\ell^2$ and Chern-Simons coefficient $1/\mu$ in the region $\mu^2 \ell^2 < 27$. It is given by a real line fibration over two-dimensional de Sitter space and is equivalent to the rotating Nariai geometry at fixed polar angle. We study the thermodynamic and asymptotic structure of a family of geometries with warped dS$_3$ asymptotics. Interestingly, these solutions have both a cosmological horizon and an internal one, and their entropy is unbounded from above unlike black holes in regular de Sitter space. The asymptotic symmetry group resides at future infinity and is given by a semi-direct product of a Virasoro algebra and a current algebra. The right moving central charge vanishes when $\mu^2 \ell^2 = 27/5$. We discuss the possible holographic interpretation of these de Sitter-esque spacetimes.Comment: 22 pages, 1 figure; v2: typos corrected, to match with published versio

Linear Collider Capabilities for Supersymmetry in Dark Matter Allowed Regions of the mSUGRA Model

Recent comparisons of minimal supergravity (mSUGRA) model predictions with WMAP measurements of the neutralino relic density point to preferred regions of model parameter space. We investigate the reach of linear colliders (LC) with $\sqrt{s}=0.5$ and 1 TeV for SUSY in the framework of the mSUGRA model. We find that LCs can cover the entire stau co-annihilation region provided \tan\beta \alt 30. In the hyperbolic branch/focus point (HB/FP) region of parameter space, specialized cuts are suggested to increase the reach in this important ``dark matter allowed'' area. In the case of the HB/FP region, the reach of a LC extends well past the reach of the CERN LHC. We examine a case study in the HB/FP region, and show that the MSSM parameters $\mu$ and $M_2$ can be sufficiently well-measured to demonstrate that one would indeed be in the HB/FP region, where the lightest chargino and neutralino have a substantial higgsino component.Comment: 29 pages, 15 EPS figures; updated version slightly modified to conform with published versio

Impaired perceptual learning in a mouse model of Fragile X syndrome is mediated by parvalbumin neuron dysfunction and is reversible.

To uncover the circuit-level alterations that underlie atypical sensory processing associated with autism, we adopted a symptom-to-circuit approach in the Fmr1-knockout (Fmr1-/-) mouse model of Fragile X syndrome. Using a go/no-go task and in vivo two-photon calcium imaging, we find that impaired visual discrimination in Fmr1-/- mice correlates with marked deficits in orientation tuning of principal neurons and with a decrease in the activity of parvalbumin interneurons in primary visual cortex. Restoring visually evoked activity in parvalbumin cells in Fmr1-/- mice with a chemogenetic strategy using designer receptors exclusively activated by designer drugs was sufficient to rescue their behavioral performance. Strikingly, human subjects with Fragile X syndrome exhibit impairments in visual discrimination similar to those in Fmr1-/- mice. These results suggest that manipulating inhibition may help sensory processing in Fragile X syndrome

Perivascular epithelioid cell tumor of the retroperitoneum in a young woman resulting in an abdominal chyloma

Perivascular epithelioid cell tumor (PEComa) is an extremely rare neoplasm which appears to have predominancy for young, frequently Asian, women. The neoplasm is composed chiefly of HMB-45-positive epithelioid cells with clear to granular cytoplasm and usually showing a perivascular distribution. These tumors have been reported in various organs under a variety of designations. Malignant PEComas exist but are very rare. The difficulty in determining optimal therapy, owing to the sparse literature available, led us to present this case. We report a retroperitoneal PEComa discovered during emergency surgery for abdominal pain in a 28-year-old Asian woman. The postoperative period was complicated by chylous ascites that was initially controlled by a wait-and-see policy with total parenteral nutrition. However, the chyle production gradually increased to more than 4 l per day. The development of a bacterial peritonitis resulted in cessation of production of abdominal fluid permitting normal nutrition without chylous leakage. Effective treatment for this rare complication of PEComa is not yet known; therefore, we have chosen to engage in long-term clinical follow-up

An activity-based integrated land-use transport model for urban spatial distribution simulation

This research develops an activity-based integrated land use/transport interaction model based on the concepts – activities (mainly, households and employment activities), activity location and relocation for Chinese regions. It consists of a residential and employment location sub-model, a transport sub-model and an implicit real estate rent adjustment sub-model. The model is developed to model the urban activity distribution evolution, predict urban spatial development trends and examine various planning decision implications. It spatially distributes household and employment activity change of a study area by zone based on the current activity distribution, land use policies and the accessibilities of the zones. The model is subsequently calibrated to predict the distribution of households and employment activities in Beijing metropolitan area in 2025. Model results show that the resident and employment densities are still high in central Beijing in 2025, and most zones’ resident densities are higher than their employment densities. However, there is also significant population density increase along the 6th ring road, indicating the relocation trend of the residents and businesses to the outskirts. This is consistent with the government objectives to decentralize activities within the central urban area. The paper also suggests that the model should be used mainly in examining the possible differences arising from the adoption of different policies though predicting future of a city distribution proves feasible

Integrated genomics and proteomics define huntingtin CAG length-dependent networks in mice.

To gain insight into how mutant huntingtin (mHtt) CAG repeat length modifies Huntington's disease (HD) pathogenesis, we profiled mRNA in over 600 brain and peripheral tissue samples from HD knock-in mice with increasing CAG repeat lengths. We found repeat length-dependent transcriptional signatures to be prominent in the striatum, less so in cortex, and minimal in the liver. Coexpression network analyses revealed 13 striatal and 5 cortical modules that correlated highly with CAG length and age, and that were preserved in HD models and sometimes in patients. Top striatal modules implicated mHtt CAG length and age in graded impairment in the expression of identity genes for striatal medium spiny neurons and in dysregulation of cyclic AMP signaling, cell death and protocadherin genes. We used proteomics to confirm 790 genes and 5 striatal modules with CAG length-dependent dysregulation at the protein level, and validated 22 striatal module genes as modifiers of mHtt toxicities in vivo