Numerical simulation of energy release rate for interface crack initiation due to thermal stress in environmental barrier coatings for Silicon Carbide (SIC) fiber reinforced in SIC matrix composite

1. Introduction In order to apply silicon carbide (SiC) fiber reinforced SiC matrix (SiC/SiC) composites as high-pressure turbine materials, environmental barrier coatings (EBC) is essential. EBC consists of several materials and thermal stress occurs by the difference in thermal property of EBC layers and SiC/SiC substrate during the fabrication process and usage environment. If energy release rate (ERR) exceeds interface fracture toughness, the interface crack can be initiated (Griffith theory). For structure design to maintain the property of EBC, it is necessary to theoretically predict ERR for interface crack while fracture toughness is obtained in experiments. This study is to perform numerical simulation of ERR for interface crack initiation due to thermal stress in EBC. 2. Theoretical equation for predicting ERR for interface crack in multi-layered structure In 1990’s, Suo and Hutchinson revealed that ERR for interface crack initiation in single-layered structure (isotropic elastic material, biaxial stress state) is written by strain energy of the layer multiplied by a dimensionless constant factor. To predict ERR for interface crack initiation in a multi-layered structure, we regard the coating layers above the objective interface as one layer and the other layers below the interface as a substrate. Then, ERR (G) is expressed by Here, Z′ is a dimensionless factor, σi, Ei, νi and hi are thermal stress, Young’s modulus, Poisson’s ratio and thickness of the coating layer above the objective interface, respectively. Note that Z′ is dependent not only on elastic properties of the components but also on thicknesses of the coating layers and substrate because ERR should be governed by the ‘effective’ mismatch between the layers above and below the objective interface. In order to examine the dependence of Z′ EBC layer thicknesses, we calculate ERR (GF), which is released strain energy per crack propagation area, by using thermal stress finite element method (FEM) analysis to be compared with ΠT. Please click Additional Files below to see the full abstract

Median alveolar cleft and palatal mass without a median upper cleft lip

Median cleft is rare among facial clefts, including bilateral and unilateral clefts. Median upper cleft lip and median alveolar cleft correspond to Type 14 and Type 0, respectively, in Tessier's classification system. Some authors have reported surgical procedures for median cleft. In the case of median alveolar cleft, bone grafting to the cleft side and orthodontics are generally applied, similarly to bilateral or unilateral cleft. Median alveolar cleft is usually accompanied by median upper cleft lip, the degree of which differs in each case. The symptoms include, but are not limited to, median lip defect, wide philtrum, and vermilion notch. However, an isolated alveolar cleft is extremely rare. We encountered a patient with an isolated alveolar cleft who did not have a light median upper cleft lip, such as a wide philtrum or vermilion notch. We herein report this case and describe its treatment

The added value of non-contrast 3-Tesla MRI for the pre-operative localization of hyperparathyroidism

OBJECTIVE: We investigated the efficacy of non-contrast 3-Tesla MR imaging added to the combination of sestamibi with99mTc (MIBI) scintigraphy and Ultrasonography (US) for the pre-operative localization of Primary Hyperparathyroidism (PHPT) lesions. METHODS: A total of 34 parathyroid glands, including nine normal glands, were examined with MIBI, US, and non-contrast 3-Tesla MRI. MRI was performed with the acquisition of T1- and T2-weighted images and fat-suppressed T2-weighted images. We calculated the sensitivities of MIBI, US, and the 'additional' MRI, with knowledge of the former two modalities' results. RESULTS: For the diagnosis of PHPT lesions, the sensitivity values of MIBI, US, and additional MRI were 88.0% (22/25), 84.0% (21/25), and 92.0% (23/25), respectively. Normal glands were not visualized with any modality (0/9). One lesion was detected neither with US nor MRI, but only with MIBI, with the limitation that MIBI represented no more than laterality. The two glands not identified in MRI were 4 mm and 6 mm in their size, which are within the range of normal gland's size. Two lesions were not detected with US or MIBI but were visualized with the additional MRI, which indicated that the MRI contributed an 8.0% (2/25) improvement of sensitivity, compared from that of US. Fat-suppressed T2-weighted images were useful in the identification of parathyroid lesions, as these images helped to differentiate between the lesion and the adjacent tissue. CONCLUSION: Additional non-contrast 3-Tesla MRI was a useful adjunctive tool for localization of PHPT, which improved the sensitivity of the pre-operative localization of PHPT lesions. Fat-suppressed T2-weighted images contributed to their identification. LEVEL VI: Evidence from a single descriptive or qualitative study

In vivo regeneration of rat laryngeal cartilage with mesenchymal stem cells derived from human induced pluripotent stem cells via neural crest cells

The laryngotracheal cartilage is a cardinal framework for the maintenance of the airway for breathing, which occasionally requires reconstruction. Because hyaline cartilage has a poor intrinsic regenerative ability, various regenerative approaches have been attempted to regenerate laryngotracheal cartilage. The use of autologous mesenchymal stem cells (MSCs) for cartilage regeneration has been widely investigated. However, long-term culture may limit proliferative capacity. Human-induced pluripotent stem cell-derived MSCs (iMSCs) can circumvent this problem due to their unlimited proliferative capacity. This study aimed to investigate the efficacy of iMSCs in the regeneration of thyroid cartilage in immunodeficient rats. Herein, we induced iMSCs through neural crest cell intermediates. For the relevance to prospective future clinical application, induction was conducted under xeno-free/serum-free conditions. Then, clumps fabricated from an iMSC/extracellular matrix complex (C-iMSC) were transplanted into thyroid cartilage defects in immunodeficient rats. Histological examinations revealed cartilage-like regenerated tissue and human nuclear antigen (HNA)-positive surviving transplanted cells in the regenerated lesion. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells. These results indicated that the transplanted C-iMSCs promoted thyroid cartilage regeneration and some of the iMSCs differentiated into chondrogenic lineage cells. Induced MSCs may be a promising candidate cell therapy for human laryngotracheal reconstruction

Laryngeal Cartilage Regeneration of Nude Rats by Transplantation of Mesenchymal Stem Cells Derived from Human-Induced Pluripotent Stem Cells

Previous studies transplanted human-induced pluripotent stem cells (hiPSCs)-derived mesenchymal stem cells (iMSCs) into thyroid cartilage defect of X-liked severe combined immunodeficiency (X-SCID) rats and confirmed transplanted cell survival and cartilage regeneration. Thus, this study aimed to investigate the contribution of iMSC transplantation to thyroid cartilage regeneration of nude rats. iMSCs were induced from hiPSCs via a neural crest cell lineage. Then, clumps formed from an iMSC/extracellular matrix complex were transplanted into thyroid cartilage defects in nude rats. The larynx was removed and histological and immunohistochemical analyses were performed 4 or 8 weeks after the transplantation. Human nuclear antigen (HNA)-positive cells were observed in 11 of 12 (91.7%) rats, which indicated that transplanted iMSCs survived in thyroid cartilage defects in nude rats. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells in 8 of 12 rats (66.7%), which indicated cartilage-like regeneration. Cartilage-like regeneration in nude rats in this study was comparable to the previous report on X-SCID rats (HNA-positive cells were observed in all 14 rats and cartilage-like regeneration was observed in 10 of 14 rats). This result suggests that nude rats could be an alternative to X-SCID rats in thyroid cartilage regeneration experiments using iMSCs, and this nude rat cartilage transplantation model may develop cartilage regeneration research concerning fewer problems such as infection due to immunosuppression

Safety of Silk-elastin Sponges in Patients with Chronic Skin Ulcers: A Phase I/II, Single-center, Open-label, Single-arm Clinical Trial

Background: Although traditional wound dressings such as collagen scaffolds promote granulation tissue formation, the efficacy of these dressings in chronic wounds is limited because of high susceptibility to bacterial growth. Biomaterials that can be applied to chronic wounds should have an anti-bacterial function. We previously reported that administering a silk-elastin solution that forms moisturizing hydrogels to wound surfaces of diabetic mice reduced bacterial growth and promoted granulation tissue formation compared with control or carboxymethyl cellulose hydrogels. We hypothesized that silk-elastin promotes wound healing in human chronic wounds by suppressing bacterial growth. Methods: An open-label, clinical case series was conducted with a prospective, single-arm design at Kyoto University Hospital in Kyoto, Japan. In this study, 6 patients with chronic skin ulcers of any origin (2 < ulcer area (cm2) < 25) on their lower extremities were included; patients with critical ischemia were excluded. Silk-elastin sponges were applied and covered with a polyurethane film without changing the dressing for 14 days. Inflammation triggered treatment discontinuation due to fear of infection. The primary study endpoint was adverse events, including inflammation and infection. Results: Poor hydrogel formation, possibly due to continuous exudation, was observed. No serious adverse events were noted. Two patients discontinued treatment on day 6 and day 7, respectively, due to inflammation, but they were not infected. The other 4 patients completed the 14-day silk-elastin sponge treatment without infection. Conclusion: Silk-elastin sponge is safe for chronic skin ulcers, and its ability to promote wound healing should be determined by confirmatory clinical trials

スターフルーツ（Averrhoa carambola L.） ノ チャクカ ニ オヨボス カンジョウハクヒ ケツバク テキシンショリ ノ エイキョウ

スターフルーツ（Averrhoa carambola L.）は沖縄や鹿児島などで栽培されている熱帯果樹である。本研究では，スターフルーツの着花数の増加と開花期の調節を目的として，環状剥皮，結縛，摘心および環状剥皮の幅の違いが着花に及ぼす影響について調査した。1年生の直立枝と下垂枝に分け，環状剥皮，結縛，摘心処理をそれぞれ行った結果，環状剥皮による着花促進がみられた。直立枝では花房数の有意な差はみられなかったが，下垂枝では花房数および小花数が最大であったことから，環状剥皮はスターフルーツにおいて着花促進効果が最も高い方法であると考えられた。さらに環状剥皮の幅の違いについて，1年生の枝に2.5mm, 5mm, 10mm幅でそれぞれ処理を行った。その結果，環状剥皮で着花促進効果がみられ，処理5週後の枝あたりの花房数が2.5mm幅区で最も多くなった。花房が着生している枝の割合は2.5mm, 5mm, 10mm幅区で90%以上に達した。これらの結果から，着花数増加のためにスターフルーツの枝に環状剥皮を行う場合，処理幅は2.5mmで十分であることが示された。Star fruit (Averrhoa carambola L.) is a tropical fruit tree indigenous to Java and the Moluccas Islands that bears fruit throughout the year when cultivated under tropical conditions. In Japan, it is cultivated in Okinawa and the Kyushu region and has two annual flowering periods : one from May to June and the other from September to October. Cultivation of this species has been hindered by the lack of established cultivation methods, and because it produces few flowers. Consequently, controlling the flowering period and increasing the number of flowers would be advantageous for improving star fruit production. The influence of girdling, strapping, and pinching treatments to increase flower setting were investigated in different treatment plots in a vinyl greenhouse at Tokyo University of Agriculture, Kanagawa, Japan. The treatments were performed on upright and descending branches of starfruit. Descending branches had larger numbers of flower clusters than upright branches. Compared to the control, girdling significantly increased the number of flower clusters on descending branches, but no such effect was observed on upright branches. In addition, the influence of girdling width (2.5, 5, and 10 mm) on flower setting on horizontal branches was examined. Compared to the control, the number of flower clusters increased for all girdling widths. The largest numbers of flower clusters and small flowers were observed in the 2.5 mm width girdling plot at 5 weeks after treatment. For the 2.5, 5, and 10 mm width girdling plots, more than 90% of branches had flower clusters at 5 weeks after treatment, compared to 30% in the control plot. The findings demonstrate that girdling improves flower setting in star fruit

LRRK2 but not ATG16L1 is associated with Paneth cell defect in Japanese Crohn\u27s disease patients

BACKGROUND. Morphological patterns of Paneth cells are a prognostic biomarker in Western Crohn’s disease (CD) patients, and are associated with autophagy-associated ATG16L1 and NOD2 variants. We hypothesized that genetic determinants of Paneth cell phenotype in other ethnic CD cohorts are distinct but also involved in autophagy. METHODS. We performed a hypothesis-driven analysis of 56 single nucleotide polymorphisms (SNPs) associated with CD susceptibility or known to affect Paneth cell function in 110 Japanese CD patients who underwent ileal resection. We subsequently performed a genome-wide association analysis. Paneth cell phenotype was determined by defensin-5 immunofluorescence. Selected genotype–Paneth cell defect correlations were compared to a Western CD cohort (n = 164). RESULTS. The average percentage of abnormal Paneth cells in Japanese CD was similar to Western CD (P = 0.87), and abnormal Paneth cell phenotype was also associated with early recurrence (P = 0.013). In contrast to Western CD, ATG16L1 T300A was not associated with Paneth cell defect in Japanese CD (P = 0.20). Among the 56 selected SNPs, only LRRK2 M2397T showed significant association with Paneth cell defect (P = 3.62 × 10(–4)), whereas in the Western CD cohort it was not (P = 0.76). Pathway analysis of LRRK2 and other candidate genes with P less than 5 × 10(–4) showed connections with known CD susceptibility genes and links to autophagy and TNF-α networks. CONCLUSIONS. We found dichotomous effects of ATG16L1 and LRRK2 on Paneth cell defect between Japanese and Western CD. Genes affecting Paneth cell phenotype in Japanese CD were also associated with autophagy. Paneth cell phenotype also predicted prognosis in Japanese CD. FUNDING. Helmsley Charitable Trust, Doris Duke Foundation (grant 2014103), Japan Society for the Promotion of Science (KAKENHI grants JP15H04805 and JP15K15284), Crohn’s and Colitis Foundation grant 274415, NIH (grants 1R56DK095820, K01DK109081, and UL1 TR000448)