Ultrafast light-driven simultaneous excitation of coherent terahertz magnons and phonons in multiferroic BiFeO3

The ultrafast switching of magnetization in multiferroic materials by a femtosecond laser could provide various advantages in photonics and magnonics. An efficient approach to control the light-matter interaction is the modulation of ultrafast coherent magnons and phonons in the high-frequency range. Spontaneous Raman andinfraredspectrarevealtheexcitationofmagnonsandopticalphononsinmultiferroicBiFeO3 inthesub-fewterahertz range. However, coherent control of such quasiparticles has not been achieved yet. In this study, we demonstrate that linearly polarized laser pulses simultaneously excite coherent magnons [out-of-plane ( ) and in-plane ( ) cyclone modes] and optical phonon (E mode) in BiFeO3. Experimental results in conjugation with phenomenological theory, by considering three uniformly distributed magnetic domains, reveal that impulsive stimulated Raman scattering is responsible for the generation of coherent magnons and phonons in BiFeO3. The observation of these terahertz magnon and optical phonon modes paves the way for the development of ultrafast magnetoelectro-optical devices

RENAL TRANSPLANTATION IMPROVES CARDIAC FUNCTION

There is mounting evidence that chronic kidney disease is a major contributor to severe cardiac damage. Although renal transplantation (RT) is an effective strategy in patients with end-stage renal disease (ESRD), the effects on cardiac function remain unclear. This study determined the effects of RT on left ventricular (LV) morphology and function in a retrospective longitudinal analysis of echocardiographic data collected in RT (n=17) and maintenance hemodialysis (HD ; n=19) groups from 2003 to 2008.Echocardiographic data obtained within 6 months and at over 3 years were compared with the data before transplantation. Improved blood pressure and anemia were observed with RT, but not HD. In contrast to the HD group, the left ventricular mass index (LVMI) in the RT group was decreased from 195.2 ± 52.1 to 162.5 ± 30.8 g/m2 ( p<0.05). In addition, the LV ejection fraction was improved in the RT group from 63.0 ± 17.1% to 79.5 ± 3.3% ( p<0.01), but not in the HD group. The rate of reduction of LVMI in the RT group was greater in patients with good control of hemoglobin.In conclusion, RT has beneficial effects on LV hypertrophy and function, as well as on ESRD

Controlled/Living Ring-Opening Polymerization of Glycidylamine Derivatives Using <i>t</i>‑Bu‑P₄/Alcohol Initiating System Leading to Polyethers with Pendant Primary, Secondary, and Tertiary Amino Groups

The combination of <i>t</i>-Bu-P₄ and alcohol was found to be an excellent catalytic system for the controlled/living ring-opening polymerization (ROP) of <i>N</i>,<i>N</i>-disubstituted glycidylamine derivatives, such as <i>N</i>,<i>N</i>-dibenzylglycidylamine (DBGA), <i>N</i>-benzyl-<i>N</i>-methylglycidylamine, <i>N</i>-glycidylmorpholine, and <i>N</i>,<i>N</i>-bis­(2-methoxyethyl)­glycidylamine, to give well-defined polyethers having various pendant tertiary amino groups with predictable molecular weights and narrow molecular weight distributions (typically <i>M</i>_w/<i>M</i>_n < 1.2). The <i>t</i>-Bu-P₄-catalyzed ROP of these monomers in toluene at room temperature proceeded in a living manner, which was confirmed by a MALDI-TOF MS analysis, kinetic measurement, and postpolymerization experiment. The well-controlled nature of the present system enabled the production of the block copolymers composed of the glycidylamine monomers. The polyethers having pendant primary and secondary amino groups, i.e., poly­(glycidylamine) and poly­(glycidylmethylamine), respectively, were readily obtained by the debenzylation of poly­(DBGA) and poly­(BMGA), respectively, through the treatment with Pd/C in THF/MeOH under a hydrogen atmosphere. To the best of our knowledge, this report is the first example of the controlled/living polymerization of glycidylamine derivatives, providing a rapid and comprehensive access to the polyethers having primary, secondary, and tertiary amino groups

Synthesis of Star- and Figure-Eight-Shaped Polyethers by <i>t</i>‑Bu‑P₄‑Catalyzed Ring-Opening Polymerization of Butylene Oxide

The synthesis of well-defined four-armed star-shaped poly­(butylene oxide) and figure-eight-shaped poly­(butylene oxide)­s (<i>s</i>-PBO and 8-PBO, respectively) with predicted molecular weights and narrow molecular weight distributions (<i>M</i>_w/<i>M</i>_ns) was achieved by the <i>t</i>-Bu-P₄-catalyzed ring-opening polymerization (ROP) of butylene oxide (BO). The <i>t</i>-Bu-P₄-catalyzed ROP of BO using 1,2,4,5-benzenetetramethanol as the initiator produced <i>s</i>-PBOs having number-average molecular weights (<i>M</i>_n,NMRs) ranging from ca. 4000 to 12 000 g mol^–1 and narrow <i>M</i>_w/<i>M</i>_ns of <1.03. Cleavage of the linkage between the initiator residue and PBO arms in <i>s</i>-PBO provided evidence for the homogeneous growth of each arm during the polymerization. The synthesis of 8-PBO was carried out through three reaction steps including (1) the synthesis of a PBO possessing two azido groups at the chain center ((N₃)₂-(PBO)₂) by the ROP of BO using 2,2-bis­((6-azidohexyloxy)­methy)­propane-1,3-diol as the initiator, (2) the introduction of an ethynyl group at the two ω-chain ends by etherification using propargyl bromide to give the ω,ω′-diethynyl poly­(butylene oxide) with two azido groups ((N₃)₂-(PBO-CCH)₂), and (3) the intramolecular click cyclization of (N₃)₂-(PBO-CCH)₂ using the copper­(I) bromide/<i><i>N,N</i>,N′,N″,N″</i>-pentamethyldiethylenetriamine catalyst in DMF under high dilution conditions. Size exclusion chromatography, FT-IR, and ¹H NMR measurements confirmed that the click reaction proceeded in an intramolecular fashion to give 8-PBOs having <i>M</i>_n,NMRs ranging from ca. 3000 to 12 000 g mol^–1 and narrow <i>M</i>_w/<i>M</i>_ns of <1.06. The viscosity property of <i>s</i>-PBO and 8-PBO was evaluated together with linear and cyclic PBOs (<i>l</i>-PBO and <i>c</i>-PBO, respectively). The intrinsic viscosity ([η]) of <i>l</i>-PBO, <i>c</i>-PBO, <i>s</i>-PBO, and 8-PBO decreased in the order of <i>l</i>-PBO > <i>s</i>-PBO > <i>c</i>-PBO > 8-PBO

Comparison of the occurrence of sleep bruxism under accustomed conditions at home and under polysomnography conditions in a sleep laboratory

Purpose: We aimed to clarify the relationship between the number of sleep bruxism (SB) bursts at home and in a laboratory equipped with polysomnography with audio-video recording (PSG-AV). We applied an identical single-channel wearable electromyography (EMG) device for both types of SB burst scorings. Methods: The subjects were 20 healthy student volunteers (12 men and 8 women; mean age, 21.9 years) who were clinically diagnosed with bruxism based on the criteria set forth by the International Classification of Sleep Disorders (ICSD-2). We used a wearable EMG device attached to the masseteric area (the FLA-500-SD [FLA]), for scoring SB bursts at home and in the laboratory. PSG-AV was set within the laboratory environment as well. The mean interval for both sleep studies was 28.8 days. EMG bursts with amplitudes greater than twice the baseline amplitude and with durations of longer than 0.25 s were selected. EMG bursts with amplitudes >= 5% MVC (maximum voluntary contraction), >= 10% MVC, and >= 20% MVC were selected as well. A cluster of bursts was defined as an episode. Results: In all the conditions for selecting EMG bursts specified above, the number of SB bursts and episodes recorded under laboratory conditions was statistically significantly smaller than that recorded at home. There were no statistically significant differences between the data obtained on the first and second recording days. Conclusion: The results of this study suggest that the unfamiliar environment of a sleep laboratory equipped with PSG-AV affects the emergence of SB as compared with home conditions

Automatic acquisition of CT radiation dose data: Using the diagnostic reference level for radiation dose optimization

The present work describes that we try to construct a system that collects dose information that performed CT examination from multiple facilities and unified management. The results of analysis are compared with other National diagnostic reference level (DRL), and the results are fed back to each facility and the cause of the abnormal value is investigated for dose optimization. Medical information collected 139 144 tests from 33 CT devices in 13 facilities. Although the DRL of this study is lower than that of Japan DRL, it was higher than the DRL of each country. When collecting all the examination, it is thought that the variation of the dose due to the error other than the intended imaging site is large. In future, we should continue to collect information in order to DRL renewal and we also think that it is desirable to collect information on physique and detailed scan region as well