Magnetic-field control of quantum critical points of valence transition

We study the mechanism of how critical end points of first-order valence transitions are controlled by a magnetic field. We show that the critical temperature is suppressed to be a quantum critical point (QCP) by a magnetic field, and unexpectedly, the QCP exhibits nonmonotonic field dependence in the ground-state phase diagram, giving rise to the emergence of metamagnetism even in the intermediate valence-crossover regime. The driving force of the field-induced QCP is clarified to be cooperative phenomena of the Zeeman and Kondo effects, which create a distinct energy scale from the Kondo temperature. This mechanism explains the peculiar magnetic response in CeIrIn(5) and the metamagnetic transition in YbXCu(4) for X=In as well as the sharp contrast between X=Ag and Cd.     

Anatomical Increased/Decreased Changes in the Brain Area Following Individuals with Chronic Traumatic Complete Thoracic Spinal Cord Injury

Objectives: This study aimed to investigate anatomical changes in the brain following chronic complete traumatic thoracic spinal cord injury (ThSCI) using voxel-based morphometry (VBM). That is, it attempted to examine dynamic physical change following thoracic injury and the presence or absence of regions with decreased and increased changes in whole brain volume associated with change in the manner of how activities of daily living are performed. Methods: Twelve individuals with chronic traumatic complete ThSCI (age; 21-63 years, American Spinal Injury Association Impairment Scale; grade C-D) participated in this study. VBM was used to investigate the regions with increased volume and decreased volume in the brain in comparison with healthy control individuals. Results: Decreases in volume were noted in areas associated with motor and somatosensory functions, including the right paracentral lobule (PCL)―the primary motor sensory area for lower limbs, left dorsal premotor cortex, and left superior parietal lobule (SPL). Furthermore, increased gray matter volume was noted in the primary sensorimotor area for fingers and arms, as well as in higher sensory areas. Conclusions: Following SCI both regions with increased volume and regions with decreased volume were present in the brain in accordance with changes in physical function. Using longitudinal observation, anatomical changes in the brain may be used to determine the rehabilitation effect by comparing present cases with cases with cervical SCI or cases with incomplete palsy.     

Phylogenetic relationship of psychoactive fungi based on the rRNA gene for a large subunit and their identification using the TaqMan assay

"Magic mushrooms" (MMs) are psychoactive fungi containing the and Psychotropics Control Law in Japan. Because there are many kinds of MMs and they are often sold even as dry powders in local markets, it is very difficult to identify the original species of the MMs by morphological observation. Therefore, we investigated the rRNA gene for a large subunit (LSU) of several MMs to classify them by a genetic approach. In this paper, we described the phylogeny of species of MMs based on the partial sequence (about 970 bp) of the LSU and the rapid identification of MMs using the TaqMan PCR assay.     

A 40 GHz band SIS receiver using Nb/Al?AlOx/Nb array junctions

A 40 GHz band SIS mixer receiver has been built using Nb/Al–AlOx/Nb array junctions and a 4.3 K closed cycle helium refrigerator. The minimum conversion loss of the mixer is 2±1 dB and the single sideband receiver noise temperature (T_RX (SSB)) is as low as 110±10 K at 36 GHz. T_RX (SSB) is almost constant in the IF bandwidth of 600 MHz. The mixer saturation level is as high as 15 nW, which is comparable to the injected LO power.Nobeyama Radio Observatory (NRO), a branch of the Tokyo Astronomical Observatory, University of Tokyo, is a cosmic radio observing facility open for outside users.     

Synthesis of perfluorochemicals for use as blood substitutes,part II: electrochemical fluorination of partly fluorinated compounds

Electrochemical fluorination of 2-methoxy-1,1,1-trifluoro-2-(F-methyl) octane gave the corresponding perfluorinated ether in 27% yield, along with cyclic by-products in 9%. A mixture of partly fluorinated tertiary amines, consisting of 1-dipropylamino-F-1-propene and 1-dipropylamino-2-hydryl-F-propane, did not afford a superior yield of tri(F-propyl)amine compared to the unfluorinated tripropylamine. 1-Diethylamino-2-(F-methyl)-F-1-pentene was fluorinated to give the corresponding F-tertiary amine in fairly good yields, together with 1-di(F-ethyl)amino-2-hydryl-2-(F-methyl)-F-pentane and their fragmented products. The study indicates that blocking of the α-carbon atom of an ether with F-methyl groups seems to reduce fragmentation, resulting in good yields of an unrearranged product. However, partial fluorination of a tertiary amine prior to electrochemical fluorination rather allows high yields of undesired by-products, as far as our experiments were concerned.