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Biomimetic Riblets Inspired by Sharkskin Denticles： Digitizing, Modeling and Flow Simulation

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Journal of Bionic Engineering 2018年第6期15卷 999-1011页

作者： Mariko Miyazaki Yuji Hirai Hiroshi Moriya masatsugu shimomura Akihiro Miyauchi Hao Liu Hitachi Ltd. 832-2 Horiguchi Hitachinaka Ibaraki 312-0034 Japan Chitose Institute of Science and Technology 758-65 Bibi Chitose Hokkaido 066-8655 Japan Tokyo Medical Dental University 2-3-10 Kanda-Surugadai Chiyodaku Tokyo 101-0062 Japan Chiba University 1-33 Yayoi-cho Inage-ku Chiba 263-8522 Japan

While sharkskin surface roughness in terms of denticle morphology has been hypothesized but remains yet controversial to be capable of achieving turbulent flow control and drag reduction, sharkskin-inspired ＂riblets＂ have been reported to be an effective biomimetic design. Here we address an integrated study of biomimetic riblets inspired by sharkskin denticles by combining 3D digitizing and mod- eling of＂fresh＂ denticles and computational fluid dynamic modeling of turbulent flows on a rough surface with staggered denticles and hound-tooth-patterned grooves. Realistic microstructures of denticles in five shark species of Galapagos, great white, whitetip reef, blacktip reef, and hammerhead sharks were first measured and digitized in three fold：（1） 2D imaging of lubricated sharkskin in a wet state by means of a ＂nano-suit＂ technique with a Field-Emission Scanning Electron Microscope （FE-SEM）; （2） 3D structures of sharkskin denticles with a micro-focus X-ray CT; and （3） single denticles of the five shark species in a 3D manner with 3D-CAD. The denticles at mid-body location in the five species were observed to have a structure of five non-uniform-ridges （herein termed ＂non-uniform grooves＂） with Angles Of Inclination （AOI） ranging over 20° - 32°. Hydrodynamics associated with the unique five-ridge denticles were then in- vestigated through modeling turbulent flow past a denticle-staggered skin surface. We further constructed a biomimetic riblet model inspired by the non-uniform grooves and investigated the hydrodynamic effects of height-to-spacing ratios of mid-ridge and side-ridges. Our results indicate that the morphological non-uniformity in sharkskin denticles likely plays a critical role in passively controlling local turbulent flow and point to the potential of denticle-inspired biomimetic riblets for turbulent-flow control in aquatic vehicles as well as other fluid machinery.

关键词： sharkskin denticles biommetic riblets 3D digitizing computational fluid dynamics

Preoperative albumin-bilirubin score and liver resection percentage determine postoperative liver regeneration after partial hepatectomy

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World Journal of Gastroenterology 2024年第14期30卷 2006-2017页

作者： Kazuhiro Takahashi Masahiko Gosho Yoshihiro Miyazaki Hiromitsu Nakahashi Osamu shimomura Kinji Furuya Manami Doi Yohei Owada Koichi Ogawa Yusuke Ohara Yoshimasa Akashi Tsuyoshi Enomoto Shinji Hashimoto Tatsuya Oda Department of Gastrointestinal and Hepatobiliary-Pancreatic Surgery University of TsukubaTsukuba 3058-575IbarakiJapan Department of Biostatistics University of TsukubaTsukuba 3058-575IbarakiJapan

BACKGROUND The success of liver resection relies on the ability of the remnant liver to regenerate.Most of the knowledge regarding the pathophysiological basis of liver regeneration comes from rodent studies,and data on humans are scarce.Additionally,there is limited knowledge about the preoperative factors that influence postoperative regeneration.AIM To quantify postoperative remnant liver volume by the latest volumetric software and investigate perioperative factors that affect posthepatectomy liver regenera-tion.METHODS A total of 268 patients who received partial hepatectomy were enrolled.Patients were grouped into right hepatectomy/trisegmentectomy(RH/Tri),left hepa-tectomy(LH),segmentectomy(Seg),and subsegmentectomy/nonanatomical hepatectomy(Sub/Non)groups.The regeneration index(RI)and late rege-neration rate were defined as(postoperative liver volume)/[total functional liver volume(TFLV)]×100 and(RI at 6-months-RI at 3-months)/RI at 6-months,respectively.The lower 25th percentile of RI and the higher 25th percentile of late regeneration rate in each group were defined as“low regeneration”and“delayed regeneration”.“Restoration to the original size”was defined as regeneration of the liver volume by more than 90%of the TFLV at 12 months postsurgery.RESULTS The numbers of patients in the RH/Tri,LH,Seg,and Sub/Non groups were 41,53,99 and 75,respectively.The RI plateaued at 3 months in the LH,Seg,and Sub/Non groups,whereas the RI increased until 12 months in the RH/Tri group.According to our multivariate analysis,the preoperative albumin-bilirubin(ALBI)score was an independent factor for low regeneration at 3 months[odds ratio(OR)95%CI=2.80(1.17-6.69),P=0.02;per 1.0 up]and 12 months[OR=2.27(1.01-5.09),P=0.04;per 1.0 up].Multivariate analysis revealed that only liver resection percentage[OR=1.03(1.00-1.05),P=0.04]was associated with delayed regeneration.Furthermore,multivariate analysis demonstrated that the preoperative ALBI score[OR=2.63(1.00-1.05),P=0.02;per 1.0 up]and liver resection percentage[OR=1.02(1.00

关键词： Liver regeneration Albumin-bilirubin score Liver resection percentage Partial hepatectomy Human Regeneration index

Perspective on ultrathin layered Ni-doped MoS_(2) hybrid nanostructures for the enhancement of electrochemical properties in supercapacitors

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Journal of Energy Chemistry 2023年第5期80卷 335-349,I0008页

作者： Kamarajar Prakash Santhanakrishnan Harish Shanmugasundaram Kamalakannan Thirumalaisamy Logu Masaru shimomura Jayaram Archana Mani Navaneethan Functional Materials and Energy Devices Laboratory Department of Physics and NanotechnologySRM Institute of Science and TechnologyKattankulathurChennai 603203Tamil NaduIndia Graduate School of Science and Technology Shizuoka University3-5-1 JohokuNaka-KuHamamatsuShizuoka 432-11Japan SPECIFIC Materials Research CentreFaculty of Science and EngineeringSwansea UniversitySwanseaUnited Kingdom Nanotechnology Research Center SRM Institute of Science and TechnologyKattankulathurChennai 603203Tamil NaduIndia

Over the last two decades,extensive study has been done on two-dimensional Molybdenum Sulphide(MoS_(2))due to its outstanding features in energy storage applications.Although MoS_(2)has a lot of active sulphur edges,the presence of inactive surfaces leads to limit conductivity and efficiency.Hence,in this article,we aimed to promote the additional active sites by doping various weight percentages(2%,4%,6%,8%and 10%)of Nickel(Ni)into the MoS_(2)matrix by simple hydrothermal technique,and their doping effects were investigated with the help of Physio-chemical analyses.X-ray diffraction(XRD)pattern,Raman,and chemical composition(XPS)analyses were used to confirm the Ni incorporation in MoS_(2)nanosheets.Microscopic investigations demonstrated that Ni-doped MoS_(2)nanosheets were vertically aligned with enhanced interlayer spacing.Cyclic voltammetry,Galvanostatic charge-discharge,and electrochemical impedance spectroscopy investigations were used to characterize the electrochemical characteristics.The 6%Ni-doped MoS_(2)electrode material showed better CSPof 528.7 F/g@1 A/g and excellent electrochemical stability(85%of capacitance retention after 10,000 cycles at 5 A/g)compared to other electrode materials.Furthermore,the solid-state asymmetric supercapacitor was assembled using Nidoped MoS_(2)and graphite as anode and cathode materials and analysed the electrochemical properties in the two-electrode system.To determine the impact of the Ni-atom on the MoS_(2)surface,firstprinciples computations were performed.Further,it was examined for electronic band structure,the projected density of states(PDOS)and Bader charge transfer analyses.

关键词： Ni-doped MoS_(2) Supercapacitor Cyclic voltammetry Specilic surface area Specific capacitance Stability

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Evaluation of the sperm DNA fragmentation index in infertile Japanese men by in-house flow cytometric analysis

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Asian Journal of Andrology 2022年第1期24卷 40-44页

作者： Akiyoshi Osaka Hiroshi Okada Sae Onozuka Takashi Tanaka Toshiyuki Iwahata Yukihito shimomura Yoshitomo Kobori Kazutaka Saito Kouhei Sugimoto Department of Urology Dokkyo Medical University Saitama Medical Center2-1-50 MinamikoshigayaKoshigayaSaitama 343-8555Japan International Center for Reproductive Medicine Dokkyo Medical University Saitama Medical Center2-1-50 MinamikoshigayaKoshigayaSaitama 343-8555Japan

Semen analysis has long been used to evaluate male fertility.Recently,several sperm function tests have been developed.Of those,the sperm DNA fragmentation index(DFI),which describes the status of the sperm DNA,is thought to be a suitable parameter for evaluating male fertility.However,there have been no large-scale studies on the sperm DFI of Japanese men.Therefore,we investigated the feasibility of using an in-house flow cytometry-based sperm DFI analysis based on the sperm DNA fragmentation test of sperm chromatin structure assay(SCSA)to assess male fertility in Japan.This study enrolled 743 infertile and 20 fertile Japanese men.To evaluate reproducibility,inter-and intraobserver precision was analyzed.A receiver operating characteristic curve analysis was used to set a cutoff value for the sperm DFI to identify men who could father children by timed intercourse or intrauterine insemination.The variability of the sperm DFI among fertile volunteers was determined.The relationship between semen parameters and the sperm DFI was assessed by Spearman’s rho test.A precision analysis revealed good reproducibility of the sperm DFI.The cutoff value of sperm DNA fragmentation in infertile men was 24.0%.Semen volume had no relationship with the sperm DFI.Sperm concentration,sperm motility,total motile sperm count,and percentage of normal-shaped sperm were significantly and negatively correlated with the sperm DFI.The median sperm DFI was smaller in fertile volunteers(7.7%)than that in infertile men(19.4%).Sperm DNA fragmentation analysis can be used to assess sperm functions that cannot be evaluated by ordinary semen analysis.

关键词： DNA fragmentation flow cytometry male infertility semen analysis spermatozoa

Friction reduction of glycocalyx of human endothelial cells cultured on anionic hydrogel scaffolds

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Friction reduction of glycocalyx of human endothelial cells ...

On the Boundary Limits of Monotone Sobolev Functions in Variable Exponent Orlicz Spaces

2007年全国高分子学术论文报告会

作者：陈咏梅龚建萍 Takayuki Kurokawa Masaru Tanaka Yasuda Kazunori Sadaaki Yamamoto masatsugu shimomura Yoshihito Osada Graduate School of Science Hokkaido University Sapporo 060-0810Japan Creative Research Initiative’SOUSEI’Hokkaido UniversitySapporo 001-0021 Graduate School of Science Hokkaido University Sapporo 060-0810Japan Graduate School of Science Hokkaido University Sapporo 060-0810Japan Nanotechnology Research Center Research Institute for Electronic Science Hokkaido UniversitySapporo001-0021Japan Creative Research Initiative’SOUSEI’ Hokkaido University Sapporo 001-0021 School of MedicineHokkaido UniversitySapporo 060-0810Japan Creative Research Initiative’SOUSEI’ Hokkaido University Sapporo 001-0021 Nanotechnology Research Center Research Institute for Electronic Science Hokkaido UniversitySapporo001-0021Japan Graduate School of Science Hokkaido University Sapporo 060-0810Japan

＜正＞In the in vivo vascular system,the inner surface of blood vessel is covered by a monolayer of endothelial cell（EC）that exposes to the blood flow.With great interesting, the red blood cells can deform and smoothly squeeze though the capillary of a diameter much smaller.In this process,the friction should occur between soft ECs and deformable blood red cells.Apparently,only when the surface friction between the inner surface wall of

关键词： hydrogel cell culture glycocalyx friction platelet adhesion

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Acta Mathematica Sinica,English Series 2013年第3期29卷 461-470页

作者： Toshihide FUTAMURA Tetsu shimomura Department of Mathematics Daido University Department of Mathematics Graduate School of Education Hiroshima University

Our aim in this note is to deal with boundary limits of monotone Sobolev functions with Δu∈Lp（·）logLq（·）（B）for the unit ball B Rn.Here p（·） and q（·） are variable exponents satisfying the log-H61der an... 详细信息

关键词： Monotone Sobolev functions nontangential limits tangential limits LindelSf theorem,variable exponent

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Water-assisted self-sustained burning of metallic single-walled carbon nanotubes for scalable transistor fabrication

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Nano Research 2017年第9期10卷 3248-3260页

作者： Keigo Otsuka Taiki Inoue Yuki shimomura Shohei Chiashi Shigeo Maruyama Department of Mechanical Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan Energy NanoEngineering Lab. National Institute of Advanced Industrial Science and Technology (AIST) 1-2-1 Namiki Tsukuba 305-8564 Japan

Although aligned arrays of semiconducting single-walled carbon nanotubes (s-SWNTs) are promising for use in next-generation electronics owing to their ultrathin bodies and ideal electrical properties, even a small portion of metallic (m-) counterparts causes excessive leakage in field-effect transistors (FETs). To fully exploit the benefits of s-SWNTs for use in large-scale systems, it is necessary to completely eliminate m-SWNTs from as-grown SWNT arrays and thereby obtain purely semiconducting large-area arrays, wherein numerous FETs can be flexibly built. In this study, we performed electrical burning of m-SWNTs assisted by water vapor and polymer coating to eliminate m-SWNTs over a long length for the scalable fabrication of transistors from the remaining s-SWNT arrays. During the electrical-breakdown process, the combination of water vapor and the polymer coating significantly enhanced the burning of the SWNTs, resulting in a self-sustained reaction along the nanotube axis. We found that m-SWNT segments partially remaining on the anode side resulted from one-way burning from the initial breakdown position, where Joule-heating-induced oxidation first occurred. The s-SWNT-enriched arrays obtained were used to fabricate multiple FETs with a high on-off current ratio. The results indicate the advantages of this approach over conventional electrical breakdown for the large-scale purification of s-SWNTs.

关键词： single-walled carbon nanotubes field-effect transistor selective removal electrical breakdown one-way burning

Establishment of a function embodiment knowledge base for supporting service design

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Science China(Information Sciences) 2012年第5期55卷 1008-1018页

作者： NEMOTO Yutaro AKASAKA Fumiya CHIBA Ryosuke shimomura Yoshiki Department of System Design Tokyo Metropolitan University

In service engineering,a service is represented as a functional structure that satisfies customer requirements.Specific entities and their activities are associated with a functional structure as a way to accomplish a goal.In this phase,it is important for service designers to have broad knowledge,since entities that construct a service include both human and physical products.Therefore,the extent of the designer's knowledge is the key to the enhancement of design solutions.However,few tools to support designers in the embodiment phase have been proposed.In this paper,for the purpose of constructing a function embodiment knowledge base in service design,the representational form of knowledge is proposed,and a prototype system of function embodiment knowledge base is established.Then function embodiment knowledge is collected from multiple service cases using the prototype system,and the effectiveness of knowledge base is discussed.

关键词： service engineering service design design knowledge management embodiment knowledge base

Prevalence and impact of musculoskeletal pain in Japanese gastrointestinal endoscopists:A controlled study

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World Journal of Gastroenterology 2011年第11期17卷 1488-1493页

作者： Takayasu Kuwabara Yuji Urabe Toru Hiyama Shinji Tanaka Takako shimomura Shiro Oko Masaharu Yoshi-hara Kazuaki Chayama Department of Gastroenterology and Metabolism Hiroshima University HospitalHiroshima 739-8514Japan Health Service Center Hiroshima UniversityHigashihiroshima 739-8514Japan Department of Endoscopy Hiroshima University HospitalHiroshima 739-8514Japan

AIM:To examine the frequency and prevention of musculoskeletal pain in Japanese gastrointestinal endoscopists and non-endoscopist physicians.METHODS:Questionnaires were sent to 275 endoscopists and 173 non-endoscopists working in Hiroshima University Hospital and its affiliated hospitals.RESULTS:The completed questionnaires were returned by 190(69%)endoscopists and 120(69%)non-endoscopists.The frequency of pain in the hand and wrist,and especially the left thumb,was significantly higher in endoscopists than in non-endoscopists(17%vs 6%,P=0.004).Using multivariate analysis,the only significant factor associated with this pain was the age of the endoscopist(odds ratio 2.77,95%confidence interval,1.23-6.71,P=0.018).Interestingly,endoscopists had made significantly fewer modifications to their endoscopic practices than non-endoscopists(12%vs 33%,P <0.0001)to prevent pain.CONCLUSION:Pain in the hand and wrist may be endoscopy-related.However,endoscopists made little modifications in practice to prevent such pain.More attention to prevention appears necessary.

关键词：内镜疼痛骨骼肌肉胃肠日本患病率大学医院