NHI- and NHC-supported Al(III) hydrides for amine–borane dehydrocoupling catalysis

The catalytic dehydrocoupling of amine–boranes has recently received a great deal of attention due to its potential in hydrogen storage applications. The use of aluminum catalysts for this transformation would provide an additional cost-effective and sustainable approach towards the hydrogen economy. Herein, we report the use of both N-heterocyclic imine (NHI)- and carbene (NHC)-supported Al(III) hydrides and their role in the catalytic dehydrocoupling of Me2NHBH3. Differences in the σ-donating ability of the ligand class resulted in a more stable catalyst for NHI-Al(III) hydrides, whereas a deactivation pathway was found in the case of NHC-Al(III) hydrides

Influence of amplitude regarding finger force on loudness discrimination acuity of self-generated sound

International audienc

Location-Specific Cortical Activation Changes during Sleep after Training for Perceptual Learning

Visual perceptual learning is defined as performance enhancement on a sensory task and is distinguished from other types of learning and memory in that it is highly specific for location of the trained stimulus. The location specificity has been shown to be paralleled by enhancement in functional magnetic resonance imaging (fMRI) signal in the trained region of V1 after visual training. Although recently the role of sleep in strengthening visual perceptual learning has attracted much attention, its underlying neural mechanism has yet to be clarified. Here, for the first time, fMRI measurement of human V1 activation was conducted concurrently with a polysomnogram during sleep with and without preceding training for visual perceptual learning. As a result of predetermined region-of-interest analysis of V1, activation enhancement during non-rapid-eye-movement sleep after training was observed specifically in the trained region of V1. Furthermore, improvement of task performance measured subsequently to the post-training sleep session was significantly correlated with the amount of the trained-region-specific fMRI activation in V1 during sleep. These results suggest that as far as V1 is concerned, only the trained region is involved in improving task performance after sleep

Effect of purification method of β-chitin from squid pen on the properties of β-chitin nanofibers

Published online 20 June 2016The relationship between purification methods of β-chitin from squid pen and the physicochemical properties of β-chitin nanofibers (NFs) were investigated. Two types of β-chitin were prepared, with β-chitin (a → b) subjected to acid treatment for decalcification and then base treatment for deproteinization, while β-chitin (b → a) was treated in the opposite order. These β-chitins were disintegrated into NFs using wet pulverization. The β-chitin (b → a) NF dispersion has higher transmittance and viscosity than the β-chitin (a → b) NF dispersion. For the first time, we succeeded in obtaining 3D images of the β-chitin NF dispersion in water by using quick-freeze deep-etch replication with high-angle annular dark field scanning transmission electron microscopy. The β-chitin (b → a) NF dispersion has a denser and more uniform 3D network structure than the β-chitin (a → b) NF dispersion. Widths of the β-chitin (a → b) and (b → a) NFs were approximately 8–25 and 3–10 nm, respectively.ArticleINTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. 91:987-993 (2016)journal articl

Solvation dynamics on the diffusion timescale elucidated using energy-represented dynamics theory

Okita K., Ito N., Morishita-Watanabe N., et al. Solvation dynamics on the diffusion timescale elucidated using energy-represented dynamics theory. Physical Chemistry Chemical Physics 26, 12852 (2024); https://doi.org/10.1039/D4CP00235K.Photoexcitation of a solute alters the solute-solvent interaction, resulting in the nonequilibrium relaxation of the solvation structure, often called a dynamic Stokes shift or solvation dynamics. Thanks to the local nature of the solute-solvent interaction, the characteristics of the local solvent environment dissolving the solute can be captured by the observation of this process. Recently, we derived the energy-represented Smoluchowski-Vlasov (ERSV) equation, a diffusion equation for molecular liquids, which can be used to analyze the solvation dynamics on the diffusion timescale. This equation expresses the time development for the solvent distribution on the solute-solvent pair interaction energy (energy coordinate). Since the energy coordinate can effectively treat the solvent flexibility in addition to the position and orientation, the ERSV equation can be utilized in various solvent systems. Here, we apply the ERSV equation to the solvation dynamics of 6-propionyl-2-dimethylamino naphthalene (Prodan) in water and different alcohol solvents (methanol, ethanol, and 1-propanol) for clarifying the differences of the relaxation processes among these solvents. Prodan is a solvent-sensitive fluorescent probe and is thus widely utilized for investigating heterogeneous environments. On the long timescale, the ERSV equation satisfactorily reproduces the relaxation time correlation functions obtained from the molecular dynamics (MD) simulations for these solvents. We reveal that the relaxation time coefficient on the diffusion timescale linearly correlates with the inverse of the translational diffusion coefficients for the alcohol solvents because of the Prodan-solvent energy distributions among the alcohols. In the case of water, the time coefficient deviates from the linear relationship for the alcohols due to the difference in the extent of importance of the collective motion between the water and alcohol solvents

Mixed Sn–Ge Perovskite for Enhanced Perovskite Solar Cell Performance in Air

Lead-based perovskite solar cells have gained ground in recent years, showing efficiency as high as 20%, which is on par with that of silicon solar cells. However, the toxicity of lead makes it a nonideal candidate for use in solar cells. Alternatively, tin-based perovskites have been proposed because of their nontoxic nature and abundance. Unfortunately, these solar cells suffer from low efficiency and stability. Here, we propose a new type of perovskite material based on mixed tin and germanium. The material showed a band gap around 1.4–1.5 eV as measured from photoacoustic spectroscopy, which is ideal from the perspective of solar cells. In a solar cell device with inverted planar structure, pure tin perovskite solar cell showed a moderate efficiency of 3.31%. With 5% doping of germanium into the perovskite, the efficiency improved up to 4.48% (6.90% after 72 h) when measured in air without encapsulation

Bilateral Approach for Thoracoscopic Esophagectomy in a Patient with Esophageal Cancer and Solitary Posterior Thoracic Para-aortic Lymph Node Metastasis

We report a successful dissection of metastatic posterior thoracic para-aortic lymph node (No. 112aoP) via bilateral thoracoscopic surgery. With the anesthetized patient (a 73-year-old Japanese woman) in the prone position, two working ports were inserted for the left-side approach, and artificial pneumothorax was created. Thoracoscopic examination revealed a swollen LN posterior to the descending aorta. Fat and metastatic LNs posterior to the aorta were dissected from the aortic arch level to the diaphragm while preserving intercostal arteries. For the right-side approach, two working ports were inserted and a routine thoracoscopic esophagec-tomy was performed. Gastric conduit reconstruction was achieved laparoscopically. Operation time for the left thoracic procedure: 54 min; estimated blood loss: almost none. No recurrence was detected 24 months post-operatively. There are several surgical options for approaching No. 112aoP, including transhiatal, left thora-cotomy, and thoracoscopy. Although a wide dissection of the posterior thoracic para-aortic area has not been reported, it may be feasible and safe if the artery of Adamkiewicz and intercostal arteries are preserved. A min-imally invasive bilateral thoracoscopic approach for a thoracoscopic esophagectomy is safe and useful for esophageal cancer patients with solitary No. 112aoP metastasis

Nano-honeycomb electrode based QCM sensor and its application for PPI detection

An anodic aluminon oxide (AAO)-based nano honeycomb electrode was coated on a quartz crystal for use as a sensing device in a quartz crystal microbalance (QCM) to monitor the protein-protein interactions (PPIs). As examples, we detected PPIs of anti-Bcl-2 and Bcl-2, and Bcl-2 and Bax in real time. A sensor with a flat Au electrode showed a tiny frequency shift upon sample injection. However, our fabricated device could detect 10 μg/mL of Bcl-2 and Bax in sequence.2016年度関西大学研究拠点形成支援経