The cause of a low Young’s modulus was investigated in quaternary β-type Ti–Nb–Ta–Zr alloys, as the modulus is decreased to prevent bone absorption and degradation of bone quality when these alloys ...are implanted into human bones. This investigation was carried out using the alloys′ single crystals. Acoustic measurements and analysis by the Hill approximation revealed that a low Young’s modulus in a polycrystalline form is caused by the low shear modulus
c′, related to the low β-phase stability, low
c
44, and relatively low bulk modulus
B compared with those of binary Ti-based alloys. Furthermore, it was found that the single crystals had strong orientation dependence on Young’s modulus, where that in the 〈1
0
0〉-direction
E
100 is the lowest of all crystallographic orientations. For quaternary Ti–29Nb–13Ta–4.6Zr alloy (mass%),
E
100 is only ∼35
GPa, which is similar to Young’s modulus of human cortical bones as a result of the low
B and
c′. These results indicate that decreases in
c′,
c
44 and
B are essential for decreasing Young’s modulus of novel β-type Ti alloys which are expected to be developed in the near future.
Summary
Background Large or deteriorated skin defects are sometimes life threatening. There is increasing evidence that adult stem cells are useful for tissue regeneration. Human mesenchymal stem ...cells (hMSCs) are self‐renewing and are potent in differentiating into multiple cells and tissues.
Objectives To investigate the effects of hMSCs in cutaneous wound healing.
Methods Wound healing was studied in an hMSC‐populated porcine skin substitute, using a nude rat model to minimize immune reactions. Full‐thickness skin and soft tissue defects of 1·5 × 1·5 cm in size, including the panniculus carnosus, were excised and covered with hMSCs and basic fibroblast growth factor (bFGF)‐soaked skin substitutes and an evaluation was made of wound size, histology and protein expression at 3, 7 and 42 days after injury.
Results The wound size was significantly smaller in the hMSC‐treated groups (P < 0·01) and any dose of bFGF (1, 10, 100 μg) enhanced the healing (P < 0·01). The re‐epithelialization markers integrin α3 and skin‐derived antileucoproteinase were remarkably increased with the presence of bFGF in a dose‐dependent manner, while the mesenchymal cell surface markers CD29 and CD44 were downregulated in a time‐dependent manner. Human pancytokeratin, which does not cross‐react with rat antigens, was observed by Western blotting at 38 kDa and 42 kDa from the hMSC‐treated tissues on day 7. The expression levels were elevated by 10 μg bFGF (P < 0·01). The immunohistochemical expression of human pancytokeratin was only observed in the hMSC‐treated groups.
Conclusions These data suggest that hMSCs together with bFGF in a skin defect model accelerate cutaneous wound healing as the hMSCs transdifferentiate into the epithelium.
There is a strong need for a non-invasive measurement technique that is capable of accurately identifying the physiological condition change or heterogeneity of subcutaneous adipose tissue (SAT) by ...localizing the abnormalities within the compartment. This paper aims to investigate the feasibility of Electrical Impedance Tomography (EIT) to assess the interstitial fluid in subcutaneous adipose tissue as an enhancement method of bioelectrical impedance spectroscopy (BIS). Here, we demonstrate the preliminary result of EIT with a wearable 16 electrodes sensor. The image-based reference EIT with fat weighted threshold method is proposed. In order to evaluate the performance of our novel method, a physiological swelling experiment is conducted, and Multi-Frequency Bioelectrical Impedance Analysis (MFBIA) is also applied as a comparison with EIT results. The experimental results showed that the proposed method was able to distinguish the physiological swelling condition and effectively to remove the unexpected background noise. Furthermore, the conductivity variation in the subcutaneous layer had a good correlation with extracellular water volume change from MFBIA data; the correlation coefficient R
= 0.927. It is concluded that the proposed method provides a significant prospect for SAT assessment.
We report molecular beam epitaxy of a ferromagnetic semiconductor (Ga,Mn)Sb, which is a single crystal without detectable second phases. We report also the details of magnetotransport properties of ...(Ga,Mn)Sb and the effects of electric fields on them. The difference between the properties observed here and properties of those reported earlier for a ferromagnetic semiconductor (Ga,Mn)As, provides information critical for further understanding of fundamental and device physics of ferromagnetic semiconductors.
•A ferromagnetic semiconductor (Ga,Mn)Sb is grown by molecular beam epitaxy, which is a single crystal without detectable second phases.•The magnetotransport properties of (Ga,Mn)Sb and the effects of electric fields on them are studied.•We show some properties observed here for (Ga,Mn)Sb are different from those reported earlier for (Ga,Mn)As.•We provide information critical for further understanding of fundamental and device physics of ferromagnetic semiconductors.
Abstract Background The critical issue related to breast-conserving therapy (BCT) is that cosmetic outcomes deteriorate with long-term follow-up. There is little research for breast density as a ...predictor of cosmetic outcomes at the late stage after BCT. To improve the long-term quality of life after BCT of breast cancer patients, the correlation of volumetric breast density (VBD) and cosmetic outcome at the late stage after BCT was evaluated. Study design Breast volume, fibroglandular tissue volume, adipose tissue volume, and VBD were calculated on mammography using image analysis software (Volpara® ) in 151 patients with BCT. Furthermore, the correlation of breast density and the change of breast volume over time was analyzed on mammography in 99 patients who were followed-up long-term after BCT. Results On multivariate analysis, VBD was a predictor of cosmetic outcome after BCT with percent breast volume excised (PBVE). Decreased adipose tissue volume and increased fibrosis were more common in patients with VBD < 15%. Furthermore, remnant breast volume continued to decrease over time in low breast density patients during long-term follow-up. 93% of patients with VBD ≥ 15% and PBVE < 10% had a better cosmetic outcome, while 60% of patients with VBD < 15% and PBVE ≥ 10% had a worse cosmetic outcome after BCT. Conclusions While PBVE was involved in cosmetic outcome at the early stage after BCT, VBD was associated with cosmetic outcome at the late stage after BCT. Thus, a combination of VBD and PBVE could predict cosmetic outcome after BCT and contribute to the selection for the appropriate BCT.
Superhydrophobic surfaces were obtained easily from the mixtures of aluminum distearate (AlDS) and typical saturated fatty acids with long alkyl chains by a casting method. In contrast to a mediocre ...water contact angle of 109 ± 1° for the surface obtained from only AlDS, the mixture of AlDS and stearic acid (SA) gave a superhydrophobic surface having the contact angle of 164 ± 2° and the sliding angle of 3 ± 1° at the SA/AlDS weight ratio of 12. A homogeneous surface was not available from only SA on a macroscopic scale. To be superhydrophobic, the surface needs to take a hierarchical structure, like a table coral which consists of several tens of micrometer-size primary structure of widely branched SA crystals. In this study, the hierarchical structures were obtained by crystallizing fatty acids in the organogel composed of AlDS and a solvent, to avoid the formation of needle-like or plate-like bulky crystals as usually seen in the recrystallization of fatty acids.
Superhydrophobic surfaces were obtained easily from a mixed solution of hydrogenated castor oil (HCO) as an organogelator and a fatty acid as a crystalline compound by a casting method: a contact ...angle of 160° ± 2° and a sliding angle of 5° ± 1° were achieved on a surface prepared from the mixed solution of HCO and stearic acid (SA) at 6:4 weight ratios at 30 °C. The superhydrophobicity of the surface was attributable to a hierarchical structure which consisted of self-assembled nano-fibers of HCO and nano/micrometer-scale crystals of SA on hemispherical sub-structures having a diameter of several tens of micrometers. The hierarchical structure was formed under controlled conditions involving mixing ratios of HCO and a fatty acid, preparation temperatures, and fatty acid species. These results indicated that balance between gelation of HCO and crystallization of a fatty acid in the casting process was of importance in producing superhydrophobic surfaces.
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