Hallucinantion and illusion (author''s transl)

The value of an anaesthetic attachment during the first two postgraduate years is considered under three major headings, the value to the recent graduate, the value to the specialty, and the value to the community. The anaesthetic attachment offers all recent graduates an opportunity to perfect practical skills which should from part of the armamentarium of all doctors, and for some there is the option to acquire the ability to administer a safe anaesthetic. Exposure to the specialty at this time is important for recruitment to the specialist ranks.     

Sorption and diffusion of weak acids in nylon—dual sorption and diffusion model

The sorption and diffusion of fluoro-substituted acetic acids in nylon-6 were measured. Hydrochloric acid was also used for comparison purposes. The results were successfully interpreted quantitatively by a dual sorption model, namely by contribution of associated and dissociated species of the acids concerned. As was expected in the case of the sorption of the weakest acid among the acids used, acetic acid, the contribution of associated species is large. The analysis of the diffusion behavior of acetic acid has shown that the contribution of associated species plays a dominant role in the diffusion process in nylon.     

Diffusion of m-sulfobenzoic acid in nylon 6

Diffusion of m-sulfobenzoic acid in nylon 6 was measured by using the S-35 labelled acid as a tracer. A multimodal mechanism, identical to that in a preceding paper on sorption, was assumed, according to which the protonated acid diffused by dissolution, and the two dissociated acids diffused by competitive interaction with the charged sites in nylon 6. The concentration dependence of the diffusion coefficients was explained by the chemical potential gradient model. The monobasically dissociated species was found to be dominant in the diffusion process. Diffusion coefficients and the activation energies of diffusion did not vary significantly with pH.     

Ultralow Impedance Graphene Microelectrodes with High Optical Transparency for Simultaneous Deep Two‐Photon Imaging in Transgenic Mice

The last decades have witnessed substantial progress in optical technologies revolutionizing our ability to record and manipulate neural activity in genetically modified animal models. Meanwhile, human studies mostly rely on electrophysiological recordings of cortical potentials, which cannot be inferred from optical recordings, leading to a gap between our understanding of dynamics of microscale populations and brain‐scale neural activity. By enabling concurrent integration of electrical and optical modalities, transparent graphene microelectrodes can close this gap. However, the high impedance of graphene constitutes a big challenge toward the widespread use of this technology. Here, it is experimentally demonstrated that this high impedance of graphene microelectrodes is fundamentally limited by quantum capacitance. This quantum capacitance limit is overcome by creating a parallel conduction path using platinum nanoparticles. A 100 times reduction in graphene electrode impedance is achieved, while maintaining the high optical transparency crucial for deep two‐photon microscopy. Using a transgenic mouse model, simultaneous electrical recording of cortical activity with high fidelity is demonstrated while imaging calcium signals at various cortical depths right beneath the transparent microelectrodes. Multimodal analysis of Ca²⁺ spikes and cortical surface potentials offers unique opportunities to bridge our understanding of cellular dynamics and brain‐scale neural activity.     

Temperature Dependence of Novel Single-Photon Detectors in the Long-Wavelength Infrared Range

Novel single-photon detectors, called Charge-sensitive Infrared Phototransistor (CSIP), have been developed in the long wavelength infrared (LWIR) range. The devices are fabricated in GaAs/AlGaAs double-quantum-well (DQW) structure, and do not require ultralow temperatures (T < 1 K) for operation. Figures of merit are determined in a T-range of 4.2 K∼30 K by using a homemade all-cryogenic spectrometer. We found that the photo-signal persists up to around 30 K. Excellent specific detectivity D ^* = 9.6 × 10¹⁴ cm Hz^1/2/W and noise equivalent power NEP = 8.3 × 10⁻¹⁹ W/Hz^1/2 are derived up to T = 23 K. The dynamic range of detection exceeds 10⁶, roughly ranging from attowatt to picowatt levels. These values are by a few orders of magnitude higher than that of the state-of-the-art values of other detectors. Simple planar structure of CSIPs is feasible for array fabrication and will make it possible to monolithically integrate with reading circuit. CSIPs are, therefore, not only extremely sensitive but also suitable for practical use in wide ranging applications.     

Development of Charge Sensitive Infrared Phototransistors for the Far-Infrared Wavelength

Ultra-highly-sensitive far-infrared detectors are developed for potential application to astronomy. The detectors exploit a novel mechanism called Charge Sensitive Infrared Phototransistors (CSIPs), in which an upper quantum well (QW) in GaAs/AlGaAs double QW structures is positively charged up by photo-excitation via inter-subband transition. This causes the conductance of the lower QW channel to increase. The device is effectively a phototransistor, in which the upper QW serves as a photo-sensitive gate to the source-drain channel provided by the lower QW. Resultant extraordinary high photoconductive gain makes CSIPs so sensitive as to detect single photons. CSIPs are well established in the mid-infrared ( \(\lambda \) = 12–20  \(\upmu \) m), achieving noise equivalent power around 1.9 \(\times \) 10 \(^{-19}\) W/Hz \(^{1/2}\) with a quantum efficiency of 7 %. CSIPs have been demonstrated to work in longer wavelengths up to 45  \(\upmu \) m, but the sensitivity was not as high as in the shorter wavelengths, probably due to lower quantum efficiency. Reported here is a remarkable improvement in the performance of longer wavelength CSIPs (45  \(\upmu \) m), achieved primarily by optimizing the doping concentration in the upper QW. This work indicates that longer wavelength CSIPs are promising detectors for the astronomical application.     

Dual mode diffusion of NaCl in Japanese radish under cooking conditions

ABSTRACT:  Sorption and diffusion of NaCl in Japanese radish have been studied. The sorption isotherm was obtained at 98 °C by the conventional method. The concentration profile by the 1-dimensional diffusion of NaCl in Japanese radish from the 3.0% solution was measured at 98 °C with the FRITRUC method involving a foodstuff rod in a thin rubber casing. Fick's diffusion coefficient, D , calculated therefrom showed a threefold variation with a maximum. This variation was quantitatively interpreted by applying a dual-mode sorption and diffusion theory under an assumption that the rate determining step of the diffusion is that in the cell wall. Two thermodynamic diffusion coefficients, D_T ( p ) and D_T ( L ), where p and L are the species of NaCl sorbed by partition and Langmuir modes, respectively, a parameter, α, derived from the local equilibrium relations between the p and L species, and S , the concentration of the Langmuir adsorption site in the cell wall of the radish, were estimated. D_T ( p ) was found to be smaller than D_T ( L ). As an explanation of the larger D_T ( L ), we invoked the higher hydration state of the adsorption site of the L species, being ascribed to residual anionic pectin in the radish than the local environment of the p species. The sorption isotherm showed a convex upward deviation from the linear relation. By using the parameters for the local equilibrium and some assumed parameters, the isotherm was found to be explainable. We suggest possible applications of the present method and interpretation to the diffusion study on the cooking systems comprising varieties of seasoning components and foodstuffs.