alpha-(Aminomethyl)acrylate: polymerization and spontaneous post-polymerization modification of beta-amino acid ester for a pH/temperature-responsive material

First published online 16 Jun 2015Ethyl α-(aminomethyl)acrylate, a β-amino acid ester carrying a conjugated vinylidene group at the α-position, was radically polymerized. The polymerization was found to involve subsequent ester–amide exchange reaction between the amino pendants of the polymer and an ester group of the monomer, affording acrylamide-bearing units in 11–15% contents. The obtained polymer exhibited pH/temperature responsiveness in aqueous media.ArticlePOLYMER CHEMISTRY. 6(28):5026-5029 (2015)journal articl

Statistical analysis method for the worldvolume hybrid Monte Carlo algorithm

We discuss the statistical analysis method for the worldvolume hybrid Monte Carlo (WV-HMC) algorithm [M. Fukuma and N. Matsumoto, Prog. Theor. Exp. Phys. 2021, 023B08 (2021)], which was recently introduced to substantially reduce the computational cost of the tempered Lefschetz thimble method. In the WV-HMC algorithm, the configuration space is a continuous accumulation (worldvolume) of deformed integration surfaces, and sample averages are considered for various subregions in the worldvolume. We prove that, if a sample in the worldvolume is generated as a Markov chain, then the subsample in the subregion can also be regarded as a Markov chain. This ensures the application of the standard statistical techniques to the WV-HMC algorithm. We particularly investigate the autocorrelation times for the Markov chains in various subregions, and find that there is a linear relation between the probability of being in a subregion and the autocorrelation time for the corresponding subsample. We numerically confirm this scaling law for a chiral random matrix model

Heat stress is a potent stimulus for enhancing rescue efficiency of recombinant Borna disease virus.

Recently developed vector systems based on Borna disease virus (BDV) hold promise as platforms for efficient and stable gene delivery to the central nervous system (CNS). However, because it currently takes several weeks to rescue recombinant BDV (rBDV), an improved rescue procedure would enhance the utility of this system. Heat stress reportedly enhances the rescue efficiency of other recombinant viruses. Here, heat stress was demonstrated to increase the amount of BDV genome in persistently BDV-infected cells without obvious cytotoxicity. Further analyses suggested that the effect of heat stress on BDV infection is not caused by an increase in the activity of BDV polymerase. More cells in which BDV replication occurs were obtained in the initial phase of rBDV rescue by using heat stress than when it was not used. Thus, heat stress is a useful improvement on the published rescue procedure for rBDV. The present findings may accelerate the practical use of BDV vector systems in basic science and the clinic and thus enable broader adoption of this viral vector, which is uniquely suited for gene delivery to the CNS

Elementary vortex pinning potential in superconductors with unconventional order parameter

The elementary vortex pinning potential is studied in unconventional superconductors within the framework of the quasiclassical theory of superconductivity. Numerical results are presented for d-, anisotropic s-, and isotropic s-wave superconductors to show explicitly that in unconventional superconductors the vortex pinning potential is determined mainly by the loss of the condensation energy in bulk due to the presence of the pinning center, i.e., by the breakdown of the Anderson's theorem. It is found that the vortex pinning energy in the d-wave pairing case is 4 -- 13 times larger than those in the s-wave pairing cases. This means that an enhancement of pinning effect in unconventional superconductors occurs due to the breakdown of the Anderson's theorem. The case of a chiral p-wave superconductor is also investigated in terms of the vortex core states subject to the Andreev reflection, where important is whether the vorticity and chirality are parallel or antiparallel.Comment: 7 pages, 4 figures included; paper for Proceedings of the symposium SDP2001, Tokyo, 200

Explicit examples of DIM constraints for network matrix models

Dotsenko-Fateev and Chern-Simons matrix models, which describe Nekrasov functions for SYM theories in different dimensions, are all incorporated into network matrix models with the hidden Ding-Iohara-Miki (DIM) symmetry. This lifting is especially simple for what we call balanced networks. Then, the Ward identities (known under the names of Virasoro/W-constraints or loop equations or regularity condition for qq-characters) are also promoted to the DIM level, where they all become corollaries of a single identity.Comment: 46 page

α-exomethylene lactone possessing acetal–ester linkage: Polymerization and postpolymerization modification for water-soluble polymer

First published: 16 October 20152,6-Dimethyl-5-methylene-1,3-dioxa-4-one (DMDO), a cyclic acrylate possessing acetal–ester linkage, was obtained as a mixture of cis- and trans-isomers (95:5) from Baylis–Hillman reaction of an aryl acrylate. The radical and anionic polymerizations of DMDO yielded the corresponding vinyl polymers without any side reactions such as cleavage of the acetal–ester linkage. The polymerization behaviors were significantly different from that of the acyclic acrylate, α-(hydroxymethyl)acrylic acid, which was expected inactive against polymerization due to the steric hindrance around the vinylidene group by the α-substituent. The acetal–ester linkage of the obtained polymer (P1) was completely cleaved via acid hydrolysis to afford a water soluble polymer, P2. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 955–961ArticleJournal of Polymer Science Part A: Polymer Chemistry. 54(7):955-961 (2016)journal articl

Nuclear Magnetic Relaxation Rate in the Vortex State of a Chiral p-Wave Superconductor

The site-selective nuclear spin-lattice relaxation rate T1^{-1} is theoretically studied inside a vortex core in a chiral p-wave superconductor within the framework of the quasiclassical theory of superconductivity. It is found that T1^{-1} at the vortex center depends on the sense of the chirality relative to the sense of the magnetic field. Our numerical result shows a characteristic difference in T1^{-1} between the two chiral states, k_x + i k_y and k_x - i k_y under the magnetic field.Comment: 2 pages, 2 figures; To be published in Physica C; Proc. of LT23, Hiroshima (Japan), 20-27 Aug. 200