Ubiquitous organic molecule-based free-standing nanowires with ultra-high aspect ratios

ごくありふれた有機分子からナノ細線をつくり立たせて埋めつくす --立体電子回路や超高感度センサーへ--. 京都大学プレスリリース. 2021-06-30.The critical dimension of semiconductor devices is approaching the single-nm regime, and a variety of practical devices of this scale are targeted for production. Planar structures of nano-devices are still the center of fabrication techniques, which limit further integration of devices into a chip. Extension into 3D space is a promising strategy for future; however, the surface interaction in 3D nanospace make it hard to integrate nanostructures with ultrahigh aspect ratios. Here we report a unique technique using high-energy charged particles to produce free-standing 1D organic nanostructures with high aspect ratios over 100 and controlled number density. Along the straight trajectory of particles penetrating the films of various sublimable organic molecules, 1D nanowires were formed with approximately 10~15 nm thickness and controlled length. An all-dry process was developed to isolate the nanowires, and planar or coaxial heterojunction structures were built into the nanowires. Electrical and structural functions of the developed standing nanowire arrays were investigated, demonstrating the potential of the present ultrathin organic nanowire systems

Surgical benefits of liver hanging maneuver for hepatectomy of huge liver tumor

In hepatic surgery, it is very important to control bleeding during liver resection. However, in hepatectomy for a huge liver tumor it is often difficult to reduce bleeding volume and maintain an excellent surgical view. The anterior pproach, which is hepatectomy done using the liver hanging maneuver, has beneficial effects reducing bleeding volume and preventing scattering of cancer cells from huge liver tumors. W e investigated the surgical benefits of the liver anging maneuver during hepatectomy for huge liver tumors in our department.

Single Crystalline, Non-stoichiometric Cocrystals of Hydrogen-Bonded Organic Frameworks

Porous frameworks composed of non-stoichiometrically mixed multicomponent molecules attract much attention from a functional viewpoint. However, their designed preparation and precise structural characterization remain challenging. Herein, we demonstrate that cocrystallization of tetrakis(4-carboxyphenyl)hexahydropyrene and pyrene derivatives (CP-Hp and CP-Py, respectively) yields non-stoichiometric mixed frameworks through networking via hydrogen bonding. The composition ratio of CP-Hp and CP-Py in the framework was determined by single crystalline X-ray crystallographic analysis, indicating that the mixed frameworks were formed over a wide range of composition ratios. Furthermore, microscopic Raman spectroscopy on the single crystal indicates that the components are not uniformly distributed such as ideal solid solution, but are done gradationally or inhomogeneously.This is the accepted version of the following article: Hashimoto T., Oketani R., Nobuoka M., et al. Single Crystalline, Non-stoichiometric Cocrystals of Hydrogen-Bonded Organic Frameworks. Angewandte Chemie - International Edition 62, e202215836 (2023), which has been published in final form at. https://doi.org/10.1002/anie.202215836. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html

Single Crystalline, Non-stoichiometric Cocrystals of Hydrogen-Bonded Organic Frameworks

This is the accepted version of the following article: Hashimoto T., Oketani R., Nobuoka M., et al. Single Crystalline, Non-stoichiometric Cocrystals of Hydrogen-Bonded Organic Frameworks. Angewandte Chemie - International Edition 62, e202215836 (2023), which has been published in final form at. https://doi.org/10.1002/anie.202215836. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html]Porous frameworks composed of non-stoichiometrically mixed multicomponent molecules attract much attention from a functional viewpoint. However, their designed preparation and precise structural characterization remain challenging. Herein, we demonstrate that cocrystallization of tetrakis(4-carboxyphenyl)hexahydropyrene and pyrene derivatives (CP-Hp and CP-Py, respectively) yields non-stoichiometric mixed frameworks through networking via hydrogen bonding. The composition ratio of CP-Hp and CP-Py in the framework was determined by single crystalline X-ray crystallographic analysis, indicating that the mixed frameworks were formed over a wide range of composition ratios. Furthermore, microscopic Raman spectroscopy on the single crystal indicates that the components are not uniformly distributed such as ideal solid solution, but are done gradationally or inhomogeneously

Ubiquitous Organic Molecule-based Free-standing Nanowires with Ultra-high Aspect Ratios

The critical dimension of semiconductor devices is approaching the single-nm regime, and a variety of practical devices of this scale are targeted for production this decade. Planar structures of nano-devices are still the center of fabrication techniques, which limit further integration of devices into a chip. Extension into 3D space is a promising strategy for future device integration; however, the steep increase in the number of surfaces and their interaction in 3D nanospace make it hard to integrate nanostructures with aspect ratios over ~10. We report herein a unique technique to produce uniform free-standing 1D nanostructures with extremely high aspect ratios over 100, borrowing from technology developed for cancer radiotherapy with high-energy charged particles. Along the straight trajectory of particles penetrating the condensed phase of a variety of sublimable organic molecules, 1D nanowires were formed with single-nm thickness and perfectly controlled length. An all-dry process was developed to isolate the nanowire plexus, and hetero-junction structures could be facilely built into the nanowires by the new technique. Coaxial extension of nanowires by a chemical process allowed us to freely design the nanowires both in axial and radial directions

Prognostic value of exercise left ventricular end-systolic volume index in patients with asymptomatic aortic regurgitation an exercise echocardiography study

BACKGROUND: Surgical timing of chronic aortic regurgitation (AR) remains a matter of debate because of limited data. This study assessed the prognostic value of exercise echocardiography in asymptomatic AR. METHODS: This prospective study included 60 consecutive asymptomatic patients with isolated moderate or severe AR (mean regurgitant volume 56.7 ± 11.8 ml) and preserved ejection fraction who underwent exercise echocardiography. The clinical outcomes were defined by the presence of major adverse cardiovascular events (MACE) and the indication for aortic valve replacement (AVR) with class I or IIa classification in the current guidelines. RESULTS: During the average follow-up of 731 days, 12 patients suffered from the clinical events, including two patients developing MACE (3%) and ten patients indicating for AVR (17%). No difference in left ventricular (LV) ejection fraction at rest was found between the patients with and without the clinical events. The indexed LV diameters and LV volumes were significantly dilated in the patients with the clinical events. The Cox proportional hazards regression analysis resulted that the exercise LV end-systolic volume index (LVESVi) was significantly associated with the clinical outcomes [hazard ratio, 1.116; 95% CI (1.032-1.205); p = 0.006]. The Kaplan-Meier analysis showed that exercise LVESVi was clearly stratified the event-free survival. CONCLUSIONS: Exercise LVESVi might be an independent predictor of prognosis in patients with asymptomatic moderate or severe AR