Finite Frequency Phase Property Versus Achievable Control Performance in H∞ Loop Shaping Design

Shinji Hara,Masaaki Kanno,Masahiko Onishi 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10

Smaller cross-sectional areas of the hamstring tendon measured from preoperative ultrasonography are likely to need additional gracilis harvesting for double-bundle anterior cruciate ligament reconstructions

Goto Kazumi,Hara Masahiko,Yamazaki Yoshiyuki,Urata Taihei,Shimizu Yuki,Shimizu Naofumi 대한슬관절학회 2020 대한슬관절학회지 Vol.32 No.-

Background/Purpose: Hamstring tendon autografts are commonly used for double-bundle anterior cruciate ligament reconstruction (DB-ACLR). If the volume of the semitendinosus (ST) tendon is insufficient, the gracilis (G) tendon is also harvested. Additional harvesting of the G autograft can affect patients’ short-term postoperative outcome, such as muscle recovery; thus, preoperative information about whether an additional G autograft is needed would be useful. The purpose of this study was to investigate whether preoperative measurement of the ST tendon using ultrasonography could inform the intraoperative decision to harvest the G tendon. Methods: We enrolled 20 patients (13 men and seven women) who underwent DB-ACLR between October 2017 and March 2019. The mean patient age was 28.5 years. The ipsilateral ST tendon was measured using ultrasonography before surgery. Measurements included the diameter and breadth of the short-axis image. The cross-sectional area (CSA) was calculated from these measurements. During surgery, when two grafts with diameters of ≥ 5.0mm could not be made, the G tendon was also harvested. Patients were categorized into two groups: the ST group where only the ST tendon was harvested, and the semitendinosus gracilis tendon (STG) group where the ST and G tendons were both harvested. The CSA value was compared between the two groups, and the cutoff value was calculated. Results: In the ST group (n = 8), the mean diameter and breadth of the semitendinosus tendon were 4.21 and 2.34mm, respectively. In the STG group (n = 12), the mean diameter and breadth of the ST tendon were 3.39 and 1.78 mm, respectively. The CSAs calculated for the ST group and the STG group were 7.74mm2 and 4.79mm2, respectively. A cutoff value of 7.0mm2 was found to correspond to a specificity and sensitivity to harvest the G tendon of 87.5% and 75.0%, respectively. Conclusions: The preoperative CSA of the ST tendon determined using ultrasonography can, therefore, be informative for deciding whether to harvest the G tendon for DB-ACLR. The results of this study provide valuable information for graft selection in anterior cruciate ligament reconstruction.

Comparative Study of Tetrahydrothiophene and Thiophene Self Assembled Monolayers on Au(111): Structure and Molecular Orientation

Ito, Eisuke,Hara, Masahiko,Kanai, Kaname,Ouchi, Yukio,Seki, Kazuhiko,Noh, Jaegeun Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.8

Surface structure and molecular orientation of self-assembled monolayers (SAMs) formed by the spontaneous adsorption of tetrahydrothiophene (THT) and thiophene (TP) on Au(111) were investigated by means of scanning tunneling microscopy (STM) and carbon K-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. STM imaging revealed that THT SAMs have a commensurate (3 ${\times}\;2\sqrt[]{3}$) structure containing structural defects in ordered domains, whereas TP SAMs are composed of randomly adsorbed domains and paired molecular row domains that can be described as an incommensurate packing structure. The NEXAFS spectroscopy study showed that the average tilt angle of the aliphatic THT ring and $\pi$-conjugated TP ring in the SAMs were calculated to be about $30^o\;and\;40^o$, respectively, from the surface normal. It was also observed that the $\pi$* transition peak in the NEXAFS spectrum of the TP SAMs is very weak, suggesting that a strong interaction between $\pi$-electrons and the Au surface arises during the self-assembly of TP molecules. In this study, we have clearly demonstrated that the surface structure and adsorption orientation of organic SAMs on Au(111) are strongly influenced by whether the cyclic ring is saturated or unsaturated.

Comparative Study of Tetrahydrothiophene and Thiophene Self-Assembled Monolayers on Au(111): Structure and Molecular Orientation

Eisuke Ito,Masahiko Hara,Kaname Kanai,Yukio Ouchi,Kazuhiko Seki,노재근 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.8

Surface structure and molecular orientation of self-assembled monolayers (SAMs) formed by the spontaneous adsorption of tetrahydrothiophene (THT) and thiophene (TP) on Au(111) were investigated by means of scanning tunneling microscopy (STM) and carbon K-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. STM imaging revealed that THT SAMs have a commensurate (3 × 2√3) structure containing structural defects in ordered domains, whereas TP SAMs are composed of randomly adsorbed domains and paired molecular row domains that can be described as an incommensurate packing structure. The NEXAFS spectroscopy study showed that the average tilt angle of the aliphatic THT ring and π-conjugated TP ring in the SAMs were calculated to be about 30o and 40o, respectively, from the surface normal. It was also observed that the π* transition peak in the NEXAFS spectrum of the TP SAMs is very weak, suggesting that a strong interaction between π-electrons and the Au surface arises during the self-assembly of TP molecules. In this study, we have clearly demonstrated that the surface structure and adsorption orientation of organic SAMs on Au(111) are strongly influenced by whether the cyclic ring is saturated or unsaturated.

Formation of Ordered 4-Fluorobenzenethiol Self-Assembled Monolayers on Au(111) from Vapor Phase Deposition

Kang, Hungu,Ito, Eisuke,Hara, Masahiko,Noh, Jaegeun American Scientific Publishers 2016 Journal of nanoscience and nanotechnology Vol.16 No.3

<P>Self-assembled monolayers (SAMs) were formed by the spontaneous adsorption of 4fluorobenzenethiol (4-FBT) on Au(111) using both solution and ambient-pressure vapor deposition methods at room temperature. The surface structure and thermal desorption properties of 4-FBT SAMs were examined by scanning tunneling microscopy (STM) and thermal desorption spectroscopy (TDS). STM imaging showed that 4-FBT SAMs formed in solution at room temperature mainly contained disordered phase with gold adatom islands, while those formed by ambientpressure vapor deposition had well-ordered phase, which can be described as a (2x2 root 13)R45 degrees structure. In addition, thermal desorption spectroscopy (TDS) measurements showed that strong desorption peak for parent mass fragment (m/z = 128, FC6H5SH+) for 4-FBT SAMs on Au(111) was observed at 460 K, as a result of hydrogen abstract reaction of chemisorbed thiolates during desorption.</P>

Surface Potential Change Depending on Molecular Orientation of Hexadecanethiol Self-Assembled Monolayers on Au(111)

Ito, Eisuke,Arai, Takayuki,Hara, Masahiko,Noh, Jaegeun Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.6

Surface potential and growth processes of hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) surfaces were examined by Kelvin probe method and scanning tunneling microscopy. It was found that surface potential strongly depends on surface structure of HDT SAMs. The surface potential shift for the striped phase of HDT SAMs chemisorbed on Au(111) surface was +0.45 eV, which was nearly the same as that of the flat-lying hexadecane layer physisorbed on Au(111) surface. This result indicates that the interfacial dipole layer induced by adsorption of alkyl chains is a main contributor to the surface potential change. In the densely-packed HDT monolayer, further change of the surface potential was observed, suggesting that the dipole moment of the alkanethiol molecules is an origin of the surface potential change. These results indicate that the work function of a metal electrode can be modified by controlling the molecular orientation of an adsorbed molecule.

Surface Potential Change Depending on Molecular Orientation of Hexadecanethiol Self-Assembled Monolayers on Au(111)

Eisuke Ito,Takayuki Arai,Masahiko Hara,노재근 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.6

Surface potential and growth processes of hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) surfaces were examined by Kelvin probe method and scanning tunneling microscopy. It was found that surface potential strongly depends on surface structure of HDT SAMs. The surface potential shift for the striped phase of HDT SAMs chemisorbed on Au(111) surface was +0.45 eV, which was nearly the same as that of the flat-lying hexadecane layer physisorbed on Au(111) surface. This result indicates that the interfacial dipole layer induced by adsorption of alkyl chains is a main contributor to the surface potential change. In the densely-packed HDT monolayer, further change of the surface potential was observed, suggesting that the dipole moment of the alkanethiol molecules is an origin of the surface potential change. These results indicate that the work function of a metal electrode can be modified by controlling the molecular orientation of an adsorbed molecule.

Surface Structure, Adsorption, and Thermal Desorption Behaviors of Methaneselenolate Monolayers on Au(111) from Dimethyl Diselenides

Lee, Sang Yun,Ito, Eisuke,Kang, Hungu,Hara, Masahiko,Lee, Haiwon,Noh, Jaegeun American Chemical Society 2014 The Journal of Physical Chemistry Part C Vol.118 No.16

<P>To understand the effect of headgroups (i.e., sulfur and selenium) on surface structure, adsorption states, and thermal desorption behaviors of self-assembled monolayers (SAMs) on Au(111), we examined methanethiolate (CH<SUB>3</SUB>–S, MS) and metheneselenolate (CH<SUB>3</SUB>–Se, MSe) monolayers formed from dimethyl disulfide (DMDS) and dimethyl diselenide (DMDSe) molecules by ambient vapor-phase deposition. Scanning tunneling microscopy imaging revealed that DMDS molecules on Au(111) after a 1 h deposition form MS monolayers containing a disordered phase and an ordered row phase with an inter-row spacing of 1.51 nm, whereas DMDSe molecules form long-range-ordered MSe monolayers with a (√3 × 3√3)<I>R</I>30° structure. X-ray photoelectron spectroscopy measurements showed that MS or MSe monolayers chemisorbed on Au(111) were formed via S–S bond cleavage of DMDS or Se–Se bond cleavage of DMDSe. On the other hand, we monitored three main desorption fragments for MS and MSe monolayers using TDS monomers (CH<SUB>3</SUB>S<SUP>+</SUP>, CH<SUB>3</SUB>Se<SUP>+</SUP>), parent mass species (CH<SUB>3</SUB>SH<SUP>+</SUP>, CH<SUB>3</SUB>SeH<SUP>+</SUP>), and dimers (CH<SUB>3</SUB>S–SCH<SUB>3</SUB><SUP>+</SUP>, CH<SUB>3</SUB>Se–SeCH<SUB>3</SUB><SUP>+</SUP>). Interestingly, we found that thermal desorption behaviors of MSe monolayers were markedly different from those of MS monolayers. All desorption peaks for MSe monolayers were observed at a higher temperature compared with MS monolayers, suggesting that the adsorption affinity of selenium atoms for the Au(111) surface is stronger than that of sulfur atoms. In addition, the desorption intensity of dimer fragments for MSe monolayers was much lower than for MS monolayers, indicating that selenolate SAMs on Au(111) did not undergo their dimerization efficiently during thermal heating compared with thiolate SAMs. Our results provide new insight into understanding the surface structure and thermal desorption behavior of MSe monolayers on Au(111) surface by comparing those of MS monolayers.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2014/jpccck.2014.118.issue-16/jp409531w/production/images/medium/jp-2013-09531w_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp409531w'>ACS Electronic Supporting Info</A></P>

Growth, solvent effects, and thermal desorption behavior of octylthiocyanate self-assembled monolayers on Au(111)

Lee, Sang Yun,Choi, Youngsik,Ito, Eisuke,Hara, Masahiko,Lee, Haiwon,Noh, Jaegeun The Royal Society of Chemistry 2013 Physical chemistry chemical physics Vol.15 No.10

<P>The growth process, solvent effects, and thermal desorption behavior of octylthiocyanate [OTC, CH<SUB>3</SUB>(CH<SUB>2</SUB>)<SUB>7</SUB>S–CN] self-assembled monolayers (SAMs) on Au(111) were characterized by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and thermal desorption spectroscopy (TDS). To investigate their growth processes, octanethiol [OT, CH<SUB>3</SUB>(CH<SUB>2</SUB>)<SUB>7</SUB>S–H] and OTC SAMs were prepared in 0.5 μM ethanol solution at room temperature as a function of immersion time: 10 min, 1 h, 2 h, and 24 h. STM imaging revealed that OT SAMs underwent a phase transition from the liquid phase containing striped-phase domains to the closely packed <I>c</I>(4 × 2) phase. OTC SAMs underwent a different phase transition from the liquid phase containing aggregated molecules to the disordered phase containing striped-phase domains. The adsorption amounts of OTC SAMs formed after immersion for 10 min and 24 h were measured to be 16% and 30% smaller than those of OT SAMs under the same conditions. STM and XPS results show that the growth kinetics of OTC SAMs on Au(111) are much slower than those of OT SAMs. Hexane resulted in OTC SAMs of higher structural quality than ethanol, DMF, or toluene. TDS measurements revealed that the relative desorption intensities of octanethiolate (C8S<SUP>+</SUP>, monomer) and dioctyl disulfide (C8SSC8<SUP>+</SUP>, dimer) to octanethiol (C8SH<SUP>+</SUP>) fragments for OTC SAMs were much weaker than those of OT SAMs. This is because desorption of monomers and dimers is strongly suppressed by low surface coverage of OTC SAMs, as revealed by STM observations.</P> <P>Graphic Abstract</P><P>The growth kinetics of OTC SAMs on Au(111) are much slower than those of OT SAMs. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cp44425b'> </P>

Two-dimensional optical feedback control of <i>Euglena</i> confined in closed-type microfluidic channels

Ozasa, Kazunari,Lee, Jeesoo,Song, Simon,Hara, Masahiko,Maeda, Mizuo Royal Society of Chemistry 2011 Lab on a chip Vol.11 No.11

<P>We examined two-dimensional (2D) optical feedback control of phototaxis flagellate <I>Euglena</I> cells confined in closed-type microfluidic channels (microaquariums), and demonstrated that the 2D optical feedback enables the control of the density and position of <I>Euglena</I> cells in microaquariums externally, flexibly, and dynamically. Using three types of feedback algorithms, the density of <I>Euglena</I> cells in a specified area can be controlled arbitrarily and dynamically, and more than 70% of the cells can be concentrated into a specified area. Separation of photo-sensitive/insensitive <I>Euglena</I> cells was also demonstrated. Moreover, <I>Euglena</I>-based neuro-computing has been achieved, where 16 imaginary neurons were defined as <I>Euglena</I>-activity levels in 16 individual areas in microaquariums. The study proves that 2D optical feedback control of photoreactive flagellate microbes is promising for microbial biology studies as well as applications such as microbe-based particle transportation in microfluidic channels or separation of photo-sensitive/insensitive microbes.</P> <P>Graphic Abstract</P><P>We developed and demonstrated 2D optical feedback control of the density and position of <I>Euglena</I> cells swimming in microaquariums. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0lc00719f'> </P>