Elastic Modulus of Osteoporotic Mouse Femur Based on Femoral Head Compression Test

A biomechanical test is a good evaluation method that describes the structural, functional, and pathological differences in the bones, such as osteoporosis and fracture. The tensile test, compression test, and bending test are generally performed to evaluate the elastic modulus of the bone using mice. In particular, the femoral head compression test is mainly used for verifying the osteoporosis change of the femoral neck. This study conducted bone mineral density analysis using in vivo microcomputed tomography (micro-CT) to observe changes in osteoporosis over time. It proposed a method of identifying the elastic modulus of the femur in the normal group (CON group) and the osteoporotic group (OVX group) through finite element analysis based on the femoral head compression test and also conducted a comparative analysis of the results. Through the femoral head compression test, it was verified that the CON group’s ultimate and yield loads were significantly higher than those of the OVX group. It was considered that this result was caused by the fact that the bone mineral density change by osteoporosis occurred in the proximal end more often than in the femur diaphysis. However, the elastic modulus derived from the finite element analysis showed no significant difference between the two groups

Synthesis and impedance studies of CuTa2-2xO6-5x perovskites

Polycrystalline samples of CuTa2-2xO6-5x are successfully synthesised by solid state reaction at 975 °C over 24 hours and the solid solution limit is confirmed as 0 1 ≤ x ≤ 0 2. The samples are fully indexed based on cubic structure in the space group, Pmmm, International Centre for Diffraction data (ICDD) number 70-611. The refined lattice parameters for CuTa1.8O5.5 (x = 0 1) and CuTa1.6O5 (x = 0 2) are a = 7 5117 (4) and 7.5070 (16), respectively. The determined grain sizes for both samples are in the range of 0.5-3.0 μm for x = 0 1 and 1.0-4.0 μm for x = 0 2. Besides, the samples show no thermal change in a wide range of temperature studied. Meanwhile, high relative permittivity exhibited by sample x = 0 2 at room temperature is also accompanied with high dielectric loss. The recorded activation energies, Ea are relatively low ~ 0.28-0.33 eV and high conductivity in higher copper content sample. i.e., x=0.2 is probably attributed to the conductive behavior of copper

Investigation of the phase formation and dielectric properties of Bi7Ta3O18

Polycrystalline Bi7Ta3O18 was synthesised at the firing temperature of 950 °C over 18 h via conventional solid state method. It crystallised in a monoclinic system with space group C2/m, Z = 4 similar to that reported diffraction pattern in the Inorganic Crystal Structure Database (ICSD), 1-89-6647. The refined lattice parameters were a = 34.060 (3) Å, b = 7.618 (9) Å, c = 6.647 (6) Å with α = γ = 90° and β = 109.210 (7), respectively. The intermediate phase was predominantly in high-symmetry cubic structure below 800 °C and finally evolved into a low-symmetry monoclinic structured, Bi7Ta3O18 at 950 °C. The sample contained grains of various shapes with different orientations in the size ranging from 0.33–22.70 μm. The elemental analysis showed the sample had correct stoichiometry with negligible Bi2O3 loss. Bi7Ta3O18 was thermally stable and it exhibited a relatively high relative permittivity, 241 and low dielectric loss, 0.004 at room temperature, ∼30 °C and frequency of 1 MHz

Preparation and characterization of new Bi1.5-xCuNb1.5+xO7+x pyrochlores

A new pyrochlore solid solution, Bi1.5-xCuNb1.5+xO7+x has been synthesized using conventional solid state method. The synthesized ceramic samples were fired at 925ºC and their phase purities were analyzed using Shimadzu XRD-6000, X-ray powder diffractometer. The refinement process was performed using Chekcell programme with Fd-3m symmetry. The cubic pyrochlore structures were confirmed with a = 10.5024 (3) Å and 10.5092 (5) Å for x = 0.1 and x = 0.2, respectively. Lattice constants of the cubic pyrochlore have been found increased with increase of Nb content. On the other hand, the resulting powder was pelletized and sintered at sintering temperature prior to impedance spectroscopy (IS) measurement. The electrical measurement was carried out in the frequency range of 0.1 Hz – 10 MHz over a temperature from room temperature to 800ºC, in both cooling and heating cycles

Synthesis, structural and electrical properties of novel pyrochlores in the Bi2O3-CuO-Ta2O5 ternary system

A series of non-stoichiometric cubic pyrochlores with general formula, Bi3−xCu1.8Ta3+xO13.8+x (BCT) was successfully prepared by solid state reaction at the firing temperature of 950 °C over 2 days. The solid solution mechanism is proposed as one-to-one replacement of Bi3+ for Ta5+, together with a variation in oxygen content in order to achieve electroneutrality. The solid solution limit is confirmed by X-ray diffraction technique (XRD) for which linear variation of lattice constants is observed at 0 ≤ x ≤ 0.6. The refined lattice constants are found to be in the range of 10.4838 (8) Å–10.5184 (4) Å and the grain sizes of these samples determined by scanning electron microscopy (SEM) fall between 1 and 40 μm. Meanwhile, thermal analyses show no physical or chemical change for the prepared pyrochlores. The relative densities of the densified pellets for AC impedance measurements are above 85% and the measured relative permittivity, ɛ′ and dielectric loss, tan δ for composition, x = 0.2 at ambient temperature are ∼60 and 0.07 at 1 MHz, respectively. The calculated activation energies are 0.32–0.40 eV and the conductivity values, Y′ are in the order of 10−3 at 400 °C. The conduction mechanisms of BCT pyrochlores are probably attributed to the oxygen non-stoichiometry and mixed valency of copper within the structure

Novel monoclinic zirconolite in Bi2O3-CuO-Ta2O5 ternary system: phase equilibria, structural and electrical properties

Synthesis of novel monoclinic zirconolite, Bi1.92Cu0.08(Cu0.3Ta0.7)2O7.06 (β-BCT) using solid state reaction had been finalised at the firing temperature of 900 °C over 24 h. The X–ray diffraction pattern of β-BCT was fully indexed on a monoclinic symmetry, space group, C2/c with lattice constants, a = 13.1052 (8), b = 7.6749 (5), c = 12.162 (6), α = γ = 90° and β = 101.32° (1), respectively. The reaction mechanism study indicated phase formation was greatly influenced by the reaction between intermediate bismuth tantalate binary phases and CuO at elevated temperatures. β-BCT was thermally stable up to a temperature of 900 °C and contained spherulite grains with sizes ranging from 1 to 14 μm. Electrical properties of this material were characterised over a broad temperature range covering temperatures from 10 K to 874 K. At the temperature of 304 K, two semicircles were discernible in complex Cole–Cole plot showing an insulating grain boundary with Cgb = 6.63 × 10−9 F cm−1 and a bulk response capacitance, Cb = 6.74 × 10−12 F cm−1. The Power law frequency-dependent ac conductivity of β-BCT was apparent in three frequency regimes; a low–frequency plateau regime, a high-frequency plateau regime and a dispersive regime taking place in the temperature range of 220–576 K. The frequency-dependent ac conductivity of β-BCT with increasing temperature was attributed to the thermal activated electrical conduction mechanism within the structure

Autoimmune Hypoglycemia in a Patient with Characterization of Insulin Receptor Autoantibodies

BackgroundType B insulin resistance syndrome is a manifestation of autoantibodies to the insulin receptor that results in severe hyperglycemia and acanthosis nigricans. However, the mechanisms by which these autoantibodies induce hypoglycemia are largely unknown. In this paper, we report the case of patient with type B insulin resistance syndrome who presented with frequent severe fasting hypoglycemia and acanthosis nigricans.MethodsTo evaluate the mechanism of hypoglycemia, we measured the inhibition of insulin binding to erythrocytes and IM9 lymphocytes in a sample of the patient's dialyzed serum before and after immunosuppressive therapy.ResultsIn the patient's pre-treatment serum IgG, the binding of 125I-insulin to erythrocytes was markedly inhibited in a dose-dependent manner until the cold insulin level reached 10-9 mol/L. We also observed dose-dependent inhibition of insulin binding to IM9 lymphocytes, which reached approximately 82% inhibition and persisted even when diluted 1:20. After treatment with glucocorticoids, insulin-erythrocyte binding activity returned to between 70% and 80% of normal, while the inhibition of insulin-lymphocyte binding was reduced by 17%.ConclusionWe treated a patient with type B insulin resistance syndrome showing recurrent fasting hypoglycemia with steroids and azathioprine. We characterized the patient's insulin receptor antibodies by measuring the inhibition of insulin binding

Amnesia and Pain Relief after Cardiopulmonary Resuscitation in a Cancer Pain Patient: A Case Report

The mechanism of chronic pain is very complicated. Memory, pain, and opioid dependence appear to share common mechanism, including synaptic plasticity, and anatomical structures. A 48-yr-old woman with severe pain caused by bone metastasis of breast cancer received epidural block. After local anesthetics were injected, she had a seizure and then went into cardiac arrest. Following cardiopulmonary resuscitation, her cardiac rhythm returned to normal, but her memory had disappeared. Also, her excruciating pain and opioid dependence had disappeared. This complication, although uncommon, gives us a lot to think about a role of memory for chronic pain and opioid dependence

Impacts of coexisting bronchial asthma on severe exacerbations in mild-to-moderate COPD : results from a national database

Acknowledgments The authors would like to thank Kyungjoo Kim for the confident statistical analyses in this work. This study was supported by a grant (2014P3300300) from the Korea Centers for Disease Control and Prevention. The abstract of this paper was presented at the Asian Pacific Society of Respirology 20th Congress as an oral presentation with interim findings. The poster’s abstract was published in “Poster Abstracts” in Respirology.Peer reviewedPublisher PD

Phase equilibria in the Bi2O3-CuO-Nb2O5 ternary system

A complete subsolidus ternary phase diagram of the Bi2O3-CuO-Nb2O5 (BCN) system was constructed. Careful firing control and phase analysis were applied to determine the phase assemblages and compatibilities over a wide range of temperatures, i.e. 700–925 °C. Phase-pure BCN pyrochlores were found to crystallise in cubic symmetry, space group Fd3m, No. 227 with lattice constants in the range of 10.4855 (5)<x<10.5321 (3). The mechanism of this limited subsolidus series could be represented by a general formula, Bi3.08−xCu1.84+2x/9Nb3.08+7x/9O14.16+6x/9 (0≤x≤0.36) wherein the reduction in Bi content was compensated by a proportion amount of copper and niobium together with non-stoichiometry in oxygen