Effects of volatile additives in solutions used to prepare polythiophene-based thin-film transistors

We investigate the effects of volatile additives in solutions used to prepare thin-film transistors (TFTs) of regioregular poly(3-hexylthiophene) (P3HT). We use the additives trifluoromethylbenzene (TFMB) and methylcyclohexane (MCH) because they are poor solvents for P3HT. The additives improve the performance of the resulting TFTs when the boiling point (T(b)) of the major solvent, carbon tetrachloride, is lower than that of the additive. The maximum mobility is (4.0 +/- 60.9) x 10(-2) cm(2)V(-1)s(-1), which is 6.1 times larger than that of TFTs prepared without TFMB or MCH added to the solution; the on/off ratio and the subthreshold slope were also improved. The relative T(b) of the solvent and the additive affected the film formation with the amount of TFMB or MCH remaining at the final stage of thin film deposition influencing the precipitation of P3HT aggregates. (C) 2011 American Institute of Physics. [doi:10.1063/1.3553878]ArticleJOURNAL OF APPLIED PHYSICS. 109(5):54504 (2011)journal articl

Oxidative Modification to Cysteine Sulfonic Acid of Cys111 in Human Copper-Zinc Superoxide Dismutase

Copper-zinc superoxide dismutase (SOD1) plays a protective role against oxidative stress. On the other hand, recent studies suggest that SOD1 itself is a major target of oxidative damage and has its own pathogenicity in various neurodegenerative diseases, including familial amyotrophic lateral sclerosis. Only human and great ape SOD1s among mammals have the highly reactive free cysteine residue, Cys111, at the surface of the SOD1 molecule. The purpose of this study was to investigate the role of Cys111 in the oxidative damage of the SOD1 protein, by comparing the oxidative susceptibility of recombinant human SOD1 modified with 2-mercaptoethanol at Cys111 (2-ME-SOD1) to wild-type SOD1. Wild-type SOD1 was more sensitive to oxidation by hydrogen peroxide-generating fragments, oligomers, and charge isomers compared with 2-ME-SOD1. Moreover, wild-type SOD1, but not 2-ME-SOD1, generated an upper shifted band in reducing SDS-PAGE even by air oxidation. Using mass spectrometry and limited proteolysis, this upper band was identified as an oxidized subunit of SOD1; the sulfhydryl group (Cys-SH) of Cys111 was selectively oxidized to cysteine sulfinic acid (Cys-SO2H) and to cysteine sulfonic acid (Cys-SO3H). The antibody raised against a synthesized peptide containing Cys111-SO3H reacted with only the Cys111-peroxidized SOD1 by Western blot analysis and labeled Lewy bodylike hyaline inclusions and vacuole rims in the spinal cord of human SOD1-mutated amyotrophic lateral sclerosis mice by immunohistochemical analysis. These results suggest that Cys111 is a primary target for oxidative modification and plays an important role in oxidative damage to human SOD1, including familial amyotrophic lateral sclerosis mutants.This work was supported by Grants-in-aid for Scientific Research 17500242 and 19500313; a Hitech Research Center grant and the 21st Century Centers of Excellence program from the Ministry of Education, Culture, Sports, Science and Technology of Japan; and in part by a Grant for the Research Group on Development of Novel Therapeutics for ALS from the Ministry of Health, Labor and Welfare of Japan. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact

Non-Fermi-Liquid Scaling in Ce(Ru_{0.5}Rh_{0.5})_2Si_2

We study the temperature and field dependence of the magnetic and transport properties of the non-Fermi-liquid compound Ce(Ru_{1-x}Rh_x)_2Si_2 at x=0.5. For fields $\lesssim$0.1T the experimental results show signatures of the presence of Kondo-disorder, expected to be large at this concentration. For larger fields, however, magnetic and transport properties are controlled by the coupling of the conduction electrons to critical spin-fluctuations. The temperature dependence of the susceptibility as well as the scaling properties of the magnetoresistance are in very good agreement with the predictions of recent dynamical mean-field theories of Kondo alloys close to a spin-glass quantum critical point.Comment: 4 pages, 4 figures. Improved discussion. To appear in Phys. Rev. Let

新しいカルパイン阻害剤はラット生体位心における緩和な虚血再灌流による左心室機能障害を保護する

We have previously indicated that a new soluble calpain inhibitor, SNJ-1945 (SNJ), attenuates cardiac dysfunction after cardioplegia arrest-reperfusion by inhibiting the proteolysis of α-fodrin in in vitro study. Nevertheless, the in vivo study design is indispensable to explore realistic therapeutic approaches for clinical use. The aim of the present in situ study was to investigate whether SNJ attenuated left ventricular (LV) dysfunction (stunning) after mild ischemic-reperfusion (mI-R) in rat hearts. SNJ (60 μmol/l, 5 ml i.p.) was injected 30 min before gradual and partial coronary occlusion at proximal left anterior descending artery. To investigate LV function, we obtained curvilinear end-systolic pressure–volume relationship by increasing afterload 60 min after reperfusion. In the mI-R group, specific LV functional indices at midrange LV volume (mLVV), end-systolic pressure (ESPmLVV), and pressure–volume area (PVAmLVV: a total mechanical energy per beat, linearly related to oxygen consumption) significantly decreased, but SNJ reversed these decreases to time control level. Furthermore, SNJ prevented the α-fodrin degradation and attenuated degradation of Ca2+ handling proteins after mI-R. Our results indicate that improvements in LV function following mI-R injury are associated with inhibition of the proteolysis of α-fodrin in in situ rat hearts. In conclusion, SNJ should be a promising tool to protect the heart from the stunning.博士（医学）・甲617号・平成26年3月17

Alteration of Concanavalin A Binding Glycoproteins in Cerebrospinal Fluid and Serum of Alzheimer's Disease Patients

Alzheimer’s disease (AD) is the most common cause of dementia in the elderly. It is characterized pathologically by the formation of senile plaques and neurofibrilly tangles in the brain. Diagnostic markers for detecting earlier stages of AD are needed. We measured the intensity of concanavalin A (Con A) binding activities of glycoproteins of the cerebrospinal fluid (CSF) and serum of subjects to clarify the modification of core mannose since we expected that aberrant glycosylation of glycoproteins might be useful as a new biomarker for detecting AD. CSF samples were collected from 15 patients with probable AD (AD group), 5 patients with probable dementia with Lewy bodies (DLB) (DLB group) and 8 controls without dementia (control group), whereas serum samples from 20 patients with probable AD and 20 controls without dementia were also collected. Glycoproteins in the CSF and serum were detected by lectin blotting using Con A. In the CSF of the AD group, 2 Con A binding glycoproteins were significantly higher compared with the control group. Furthermore, using analysis of variance, 3 Con A binding glycoproteins detected from the CSF of the AD group showed significant differences among the 3 groups. The levels of 3 Con A binding glycoproteins were significantly lower than in non-dementia controls in the serum. These changes in Con A binding activities did not depend on the amount of proteins. Therefore, the data indicate that the aberrance of protein glycosylation relates to the pathology of AD, and has some promise as a new biomarker for the diagnosis of AD

Susceptibility Inhomogeneity and Non-Fermi-Liquid Behavior in Ce(Ru_{0.5}Rh_{0.5})_2Si_2

Magnetic susceptibility and muon spin rotation (\muSR) experiments have been carried out to study the effect of structural disorder on the non-Fermi-liquid (NFL) behavior of the heavy-fermion alloy Ce(Ru_{0.5}Rh_{0.5})_2Si_2. Analysis of the bulk susceptibility in the framework of disorder-driven Griffiths-phase and Kondo-disorder models for NFL behavior yields relatively narrow distributions of characteristic spin fluctuation energies, in agreement with \muSR linewidths that give the inhomogeneous spread in susceptibility. \muSR and NMR data both indicate that disorder explains the "nearly NFL" behavior observed above \sim2 K, but does not dominate the NFL physics found at low temperatures and low magnetic fields.Comment: 6 pages, 4 figures, REVTeX, submitted to Phys. Rev.

Bisecting GlcNAc Is a General Suppressor of Terminal Modification of N-glycan

Glycoproteins are decorated with complex glycans for protein functions. However, regulation mechanisms of complex glycan biosynthesis are largely unclear. Here we found that bisecting GlcNAc, a branching sugar residue in N-glycan, suppresses the biosynthesis of various types of terminal epitopes in N-glycans, including fucose, sialic acid and human natural killer-1. Expression of these epitopes in N-glycan was elevated in mice lacking the biosynthetic enzyme of bisecting GlcNAc, GnT-III, and was conversely suppressed by GnT-III overexpression in cells. Many glycosyltransferases for N-glycan terminals were revealed to prefer a nonbisected N-glycan as a substrate to its bisected counterpart, whereas no up-regulation of their mRNAs was found. This indicates that the elevated expression of the terminal N-glycan epitopes in GnT-III-deficient mice is attributed to the substrate specificity of the biosynthetic enzymes. Molecular dynamics simulations further confirmed that nonbisected glycans were preferentially accepted by those glycosyltransferases. These findings unveil a new regulation mechanism of protein N-glycosylation.This work was supported by Grant-in-Aid for Scientific Research (C) to Y.K. [17K07356], Leading Initiative for Excellent Young Researchers (LEADER) project to Y.K. from the Japan Society for the Promotion of Science (JSPS), by Takeda Science Foundation, and by Mochida Memorial Foundation for Medical and Pharmaceutical Research