In-Situ SHG Investigations on the Aggregation Behaviors of Some Amphiphilic Dyes at the Water Surface:Effects of Aliphatic Tails

The optical second harmonic generation (SHG) has been powerful for in-situ characterization of surface (interface) structures. In this paper, we describe applications of the SHG technique for structural characterization of monolayer assemblies of some amphiphilic dyes formed at the water surface. Previously, we reported the number of aliphatic tails of the amphiphilic ruthenium complexes profoundly affected the monolayer structures, as studied by the SHG technique.     

Ueber die anwendung von in vivo zersetzbaren polymeren in der thoraxchirurgie

Bioabsorbable materials for use in a clinical situation are required to have specific mechanical characteristics and predictable degradation. We have been studying the mechanical properties and the bioabsorbability of polyesters of aliphatic α-hydroxyacids, such as polylactide, polyglycolide (PGA) and their copolymers, to applying them for surgery, and classifying the effects of the factors governing their biodegradation behavior. Poly-L-lactide (P-L-LA) showed slow degradation and maintained initial mechanical properties for a period of more than 3 months after implantation. In contrast, PGA showed rapid degradation and after its absorption at the site of implantation, good replacement of the tissue was observed. On th basis of these results, various clinical applications for thoracic surgery were evaluated as follows: 1) For the fixation of fractured ribs, pins made from either P-L-LA or a composite of P-L-LA and hydroxyapatite were prepared. 2) For reconstruction of the chest wall, Tricot-Knit PGA mesh and P-L-LA mesh were fabricated. In vivo tests in dogs were then carried out. P-L-LA pins maintained the strength required for connecting the fractured ribs until complete reunion was achieved, while the meshes acted as scaffolding for reconstruction of the connective tissue. In both cases, these materials showed minimal tissue reaction and sufficient biocompatibility.     

Antiparticle Excitation Effect in the Relativistic Spin-Isospin-Dependent Response Function of Nucleus

The spin-isospin-dependent response function of nucleus is studied in the relativistic formalism. Besides the well-known relativistic particlehole and A-hole excitations, the antiparticle excitations such as nucleon-antinucleon, nucleon-antidelta, antinucleon-delta excitations are also taken into account in the calculation of the response function, and the effect of the antiparticle excitation is emphasized. The antiparticle excitation enhances the response function and its effect to the response function is largely determined by the cutoff parameter which is introduced by the need of the renormalization. The position of the peak of the A-hole resonance is mainly dominated by short range correlation Landau-Migdal parameter g', and we find g' is about 0.6. The effect of two-nucleon absorption and projectiletarget form factor are also studied.     

Synthesis of gels by means of Michael addition reaction of multi-functional acetoacetate and diacrylate compounds and their application to ionic conductive gels

Michael-addition reactions of multi-functional acetoacetate, meso-erythritol tetraacetoacetate (ETAA), trimethylolpropane triacetoacetate (TPTAA), and diacrylate compounds, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, or poly(ethylene glycol) diacrylate (PEGDA), in dimethyl sulfoxide have successfully yielded the corresponding gels in the presence of 1,8-diazabicyclo[5.5.0]undecane-7-ene as a catalyst at room temperature. The gel formation rates of the reaction systems with TPTAA were higher than those with ETAA. The gels prepared with the alkyl diacrylate compounds or low molecular weight PEGDA showed higher Young's modulus in compression test. The ETAA-PEGDA gels were also prepared in propylene carbonate containing Li ion or in an ionic liquid. These gels showed good ionic conductivity with conductivity value as high as 2.26 and 2.38 mS/cm at room temperature for the Li ion and ionic liquid containing systems respectively.     

(Hyper)polarizability density analysis for open-shell molecular systems based on natural orbitals and occupation numbers

We have developed a method for analyzing the (hyper)polarizabilities of open-shell molecular systems. This method employs the (hyper)polarizability densities based on the natural orbitals and occupation numbers, which enables us to analyze the contributions of odd electrons having various open-shell (diradical) characters. Within broken-symmetry, i.e., spin-unrestricted, single-determinant molecular orbital and density functional theory approaches, we can also remove the spin contamination effects on these quantities through spin projection. To do that, an approximate spin projected method has been elaborated and applied to the analysis of the (hyper)polarizability of multi-radical systems. As examples, typical open-shell singlet systems, 1,3-dipoles and rectangular graphene nanoflakes, are examined.