芳香族ケイ素クラスターに向けた官能性オリゴシランに関する合成研究

京都大学新制・課程博士博士(理学)甲第23022号理博第4699号新制||理||1674(附属図書館)京都大学大学院理学研究科化学専攻(主査)教授 時任 宣博, 准教授 加納 太一, 教授 依光 英樹学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDGA

Direct Generation of Vortex Laser Beams and Their Non-Linear Wavelength Conversion

Vortex laser beams are a technology that has revolutionised applications in micro- and nano-manipulation, micro-fabrication and super-resolution microscopy, and is now heralding advances in quantum communication. In order to service these, and emergent applications, the ability to generate powerful vortex laser beams with user-controlled spatial and wavefront properties, and importantly wavelength, is required. In this chapter, we discuss methods of generating vortex laser beams using both external beam conversion methods, and directly from a laser resonator. We then examine the wavelength conversion of vortex laser beams through non-linear processes of stimulated Raman scattering (SRS), sum-frequency generation (SFG), second harmonic generation (SHG) and optical parametric oscillation. We reveal that under different types of non-linear wavelength conversion, the spatial and wavefront properties of the vortex modes change, and in some cases, the spatial profile also evolve under propagation. We present a theoretical model which explains these dynamics, through decomposition of the vortex mode into constituent Hermite-Gaussian modes of the laser resonator

Functional comparison of the mouse DC-SIGN, SIGNR1, SIGNR3 and Langerin, C-type lectins

The mouse (m) DC-SIGN family consists of several homologous type II transmembrane proteins located in close proximity on chromosome 8 and having a single carboxyl terminal carbohydrate recognition domain. We first used transfected non-macrophage cell lines to compare the polysaccharide and microbial uptake capacities of three of these lectins - DC-SIGN, SIGNR1 and SIGNR3 - to another homologue mLangerin. Each molecule shares a potential mannose-recognition EPN-motif in its carbohydrate recognition domain. Using an anti-Tag antibody to follow Tag-labeled transfectants, we found that each molecule could be internalized, although the rates differed. However, mDC-SIGN was unable to take up FITC-dextran, FITC-ovalbumin, zymosan or heat-killed Candida albicans. The other three lectins showed distinct carbohydrate recognition properties, assessed by blocking FITC-dextran uptake at 37°C and by mannan binding activity at 4°C. Furthermore, only SIGNR1 was efficient in mediating the capture by transfected cells of Gram-negative bacteria, such as Escherichia coli and Salmonella typhimurium, while none of the lectins tested were competent to capture Gram-positive bacteria, Staphylococcus aureus. Interestingly, transfectants with SIGNR1 lacking the cytoplasmic domain were capable of binding FITC-zymosan in a manner that was abolished by EDTA or mannan, but not laminarin. In addition, resident peritoneal CD11b+ cells expressing SIGNR1 bound zymosan at 4°C in concert with a laminarin-sensitive receptor. Therefore these homologous C-type lectins have distinct recognition patters for microbes despite similarities in the carbohydrate recognition domains

Optical Vortices Illumination Enables the Creation of Chiral Nanostructures

We discovered that optical vortices with an annular spatial form and an orbital angular momentum owing to a helical wave front enable us to twist materials, such as metal, silicon and azo-polymer, to form various structured matters including microneedles, chiral nanostructures and chiral surface reliefs. Such structured matters will potentially open the door to advanced devices, for instance, silicon photonic device, biomedical micro-electro-mechanical systems, ultrasensitive detector for chiral chemical composites and plasmonic metasurfaces for chiral chemical reactions

Intraoperative Measurement of Crystalline Lens Diameter in Living Humans

Background: There are no reports on accurate measurement of lens equatorial diameter of the living human eye. This study aimed to measure lens equatorial diameter with a special measurement device during cataract surgery and examine the relationships with preoperative parameters. Methods: From April 7 to December 1, 2019, the equatorial diameters of 24 eyes from 24 patients who underwent cataract surgery at Kushimoto Arita Hospital were measured with a loop shaped measurement device during cataract surgery. Correlations between the value of the diameters and various preoperative parameters measured by CASIA2® were evaluated. Results: The average value of the measured equatorial diameter using the device was 10.5 ± 0.4 mm and the value estimated by circular approximation using the CASIA2® was 10.1 ± 0.7 mm. A significant difference was observed between these two groups (P = 0.016), and only a weak correlation was observed (γ = 0.31). A positive correlation was observed between equatorial diameter and anterior chamber depth (ACD) or anterior chamber width (ACW) (γ = 0.57 and 0.47, respectively). No significant correlation was found between other parameters and the value measured by the device. Conclusion: Our method is a completely new approach to measuring the living human lens equatorial region of the eye. No complications were observed in any of the cases. One new finding was the values of the lens equatorial diameters are actually longer than those reported previously. The results suggest that the values of the equatorial diameter measured by the loop device and those estimated by CASIA2® measurement were closer than those reported previously by other methods, although both were slightly different. We conclude that it is still difficult to estimate the equatorial diameter of the living human lens using preoperative examination parameters. This research will greatly contribute to the development of accommodative intraocular lenses in the future

Propagation-invariant vortex Airy beam whose singular point follows its main lobe

We propose and demonstrate a novel vortex Airy beam which is a superposition of an Airy beam and its laterally sheared beam with a $\pi/2$ phase shift. This new-type of vortex Airy beam exhibits stable propagation dynamics, wherein its singular point closely follows its main lobe, unlike conventional vortex Airy beams. Notably, the orbital angular mode purity of this new vortex Airy beam is up to 10% better than that of a conventional vortex Airy beam. We anticipate that this new type of vortex Airy beam, which combines the characteristics of an optical vortex and a diffraction-free Airy beam, will facilitate new directions in applications such as microscopy, material processing and nonlinear optics