CO2 レーザーでアパタイトを溶着させたPEEK ディスク上における、ラット骨髄間葉系細胞の骨形成能に関する培養実験

Background: Polyether-ether-ketone (PEEK) is increasingly being used for spinal applications. However, because of its biologically inactive nature, there are risks of false joint loosening and sinking. PEEK materials are coated with apatite to enhance the osteoconductive properties. In this study, we aimed to evaluate whether strontium apatite stimulate osteogenesis on the surface of PEEK by using the CO2 laser technique. Methods: We prepared non-coated disks, laser-exposed disks without apatite, and four types of apatite-coated by laser PEEK disks (hydroxyapatite (HAP), strontium hydroxyapatite (SrHAP), silicate-substituted strontium apatite (SrSiP), and silicate-zinc-substituted strontium apatite (SrZnSiP)). A part of the study objective was testing various types of apatite coatings. Bone marrow mesenchymal cells (BMSCs) of rats were seeded at a density of 2 × 104/cm2 onto each apatite-coated, non-coated, and laser-irradiated PEEK disks. The disks were then placed in osteogenic medium, and alkaline phosphatase (ALP) staining and Alizarin red staining of BMSCs grown on PEEK disks were performed after 14 days of culture. The concentrations of osteocalcin (OC) and calcium in the culture medium were measured on days 8 and 14 of cell culture. Furthermore, mRNA expression of osteocalcin, ALP, runt-related transcription factor 2 (Runx2), collagen type 1a1 (Col1a1), and collagen type 4a1 (Col4a1) was evaluated by qPCR. Results: The staining for ALP and Alizarin red S was more strongly positive on the apatite-coated PEEK disks compared to that on non-coated or laser-exposed without coating PEEK disks. The concentration of osteocalcin secreted into the medium was also significantly higher in case of the SrHAP, SrSiP, and SrZnSiP disks than that in the case of the non-coated on day14. The calcium concentration in the PEEK disk was significantly lower in all apatite-coated disks than that in the pure PEEK disks on day 14. In qPCR, OC and ALP mRNA expression was significantly higher in the SrZnSiP disks than that in the pure PEEK disks. Conclusions: Our findings demonstrate that laser bonding of apatite-along with trace elements-on the PEEK disk surfaces might provide the material with surface property that enable better osteogenesis.博士（医学）・甲第809号・令和4年3月15日© The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data

Development of image analysis for detection of defects of BGA by using X-ray images

In the surface mount technology, Ball Grid Array (BGA) has been used in a production of PC boards, because of their excellent characters such as high density of the lead pin pitch, better lead rigidity and self-alignment during re-flow processing. This paper deals with the development of image analysis for the detection of defects at BGA solder joints in PC boards by using X-ray images. In the conventional IC boards, it is possible to detect defects of solder joints by visual inspection, because the lead of IC package is set on its outside. However, we can't detect visually defects at BGA solder joints, because they are hidden under the IC package. In a production line, the inspection of BGA in PC boards depends on the function test of electric circuits in the final process. To improve a cost performance and the reliability of PC boards, an inspection of BGA is required in the surface mount process. Types of defects at BGA solder joints are solder bridge, missing connection, solder voids, open connection and miss-registration of parts. As we can find mostly solder bridge in these defects, we pick up this to detect solder bridge in a production line. The problems of image analysis for the detection of defects at BGA solder joints are the detection accuracy and image processing time according to a line speed of production. To get design data for the development of the inspection system, which can be used easily in the surface mount process, it is important to develop image analysis techniques based on X-ray image data. At the first step of our study, we attempt to detect the characteristic of the solder bridges based on an image analysis. </p

Detection of defects at BGA solder joints by using X-ray imaging

In the surface mount technology, a ball grid array (BGA) has been used in the production of PC boards. This paper deals with the detection of defects at BGA solder joints in PC boards by using X-ray imaging. Types of defects at BGA solder joints are solder bridge, missing connection, solder voids, open connection and misregistration of parts. The problems of image analysis for the detection of defects at BGA solder joints are the detection accuracy and image processing time according to the speed of the production line. To get the design data for the development of the inspection system used in the surface mount process, it is important to develop image analysis techniques based on X-ray image data. At the first step of our study, we attempt to detect the characteristics of the solder bridges based on the image analysis technique. </p

ケイ酸/亜鉛置換ストロンチウムアパタイトコーティングによるβ-リン酸カルシウムの骨誘導能促進効果

Background: β-Tricalcium phosphate (β-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of β-TCP could enhance osteoinductive properties. Methods: The apatite-coated β-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP). Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated β-TCP disks. In vitro, the β-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the β-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically. Results: Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group. Conclusions: Our findings indicate that apatite coating of β-TCP improves osteoinductive properties without inducing significant cytotoxicity.博士（医学）・甲第805号・令和3年12月21日© 2021. The Author(s).Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data

婦人農作業衣に関する研究(第5報) : 動作時の着ごこちに影響を及ぼす部位の検討

"以上動作時の着心地に彩管を及ぼす部位と袖構成との関係を検討し,次の結果を得た.1.着心地に影響を及ぼす部位である腋下部の動体計測値の中で,正常立位姿勢時と比較して最大伸長差がみとめられたのは, 180°上肢上挙時の胴囲線脇点より腋窩中点を通る手首点までの,(ニ)の計測値で伸長差15.5cm, 25%の伸長率であり,110°前屈時(ホ)の計測伸長差は13.7cm, 22%の伸長率がみとめられた. 2. 180°上肢上挙時における袖機能順位は,a型が最も機能性がよく,次にb, d, cの順位にみられたが,人体と袖の構成との関係要因についてみると,a型袖は腋下部の作業衣計測値と180°上挙時の,人体計測値との寸法差,すなわち皮膚面と衣服とのずれ寸法差が,4作業衣中最小差である.又袖構造上では,腋下から袖下ヘタテ布10cm幅のマチ布がひと続きに真直ぐに縫合され,腋窩に伸長規制の縫目がないことと,上挙時の機能障害要因である袖山寸法が,最小寸法で構成されている.又上挙時腋下の伸長に対する不足寸法は,袖口がゴム形式構成のため,袖口下りの対応が容易に可能であり,被服人間工学上,よく配慮されている点などが,機能性につながる最適要因であると考えられる.その他の袖型においては,上挙時の規制要因である袖下腋下の寸法差及び袖山寸法は,b,c,dの順位に大の傾向がみられた.中でもc型袖は袖口形態が,カフス式構成のため,上挙時腋下の伸長に対する不足寸法の対応が困難で,作業衣としてはこの点が,最大不適合であると考えられた. 3. 110°前屈身姿勢における袖機能順位は,b型が最もよく,次にa, c, dの順位にみられた.人体に適合する被服は,腋下部の伸長と同時に背面の伸びにも適応出来うるゆとり量が加味された構成でなければ,適合は満足出来ない.したがって,人体を包んでいる袖部と身頃部との有機的相互作用により,機能が発揮される.上記の観点から,この部位の人体と作業衣の計測伸長さの最小寸法であるb型普通袖が,着心地が最も良く,次にa, c, dの順に寸法差の大の傾向が見られた.又構造上では,b型は背面ヨークが前報で述べた通り,人体適合位線で設定され,機能量も最適寸法で構成されているためで,a型は前屈時には,後背部襠角の縫合部に力がかかり,縫目が破断しやすい状態となる欠点がみとめられた.又c型ラグラン袖は,背部に切替線がなく,袖口がカフス形式になっているために,上肢の動きに伴なう袖丈の調節が容易に出来ず,機能が劣る.次にきもの式袖d型は,どの体型にも合うが,上肢上挙,前屈身動作には,袖付寸法が長く身八つ口開口部がないため,袖付止まりの位置に力がかかり,動作が規制されて不適である.以上,袖の構成形式の異なる代表的既製作業衣4種につき比較検討したが,作業衣購入の場合には,胸囲寸法,背幅のゆとり量,袖の構成形式,デザイン,素材等をよく吟味し,寸法的に大は小をかねる式の考えではなく,動的機能にかなった適切なゆとり量の考慮されたものを,選択購入すべきであると考える.終わりに本研究に被験者として御協力下さった,本学家政科被服コースの学生に感謝の意を表します.