An ultrafast chargeable polymer electrode based on the combination of nitroxide radical and aqueous electrolyte

A film of poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl vinylether) coated on a current collector displayed a rapid and reversible electrochemical response in aqueous electrolytes, and allowed an ultrafast full charging of 3 mC cm À2 in as short as 3 seconds by virtue of the combination of the hydrophilic radical polymer and the aqueous electrolyte possessing a high electrical conductivity. Some nitroxide radical molecules, such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), are robust and known to show a reversible redox ability in organic and aqueous solutions, 1 and they have often been studied as a redox mediator in sensors and catalysts. 4,8 Rapid charging is one of the most important performances of secondary batteries; a short charging time would lead to significant advantages in our use of portable electric devices equipped with a secondary battery. Conventional Li-ion batteries cannot be rapidly charged because the charging process involves the slow de-intercalation of lithium ions from the metal oxide cathode, often taking more than 30 minutes for full charging. On the other hand, our previously reported radical polymer battery, which was composed of a lipophilic radical polymer as the cathode active material and an organic electrolyte containing a lithium salt, such as ethylene carbonate containing LiPF 6 , performed a rapid full charging in ca. 1 minute. In this paper, we report, for the first time, an aqueous electrolyte-based radical polymer battery that has very fast charging characteristics. We have designed poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl vinylether) (PTVE) as an electrodeactive and hydrophilic polyvinylether-backboned polymer bearing a TEMPO pendant group (Scheme 1), which shows a reversible one-electron oxidation capability even in aqueous electrolytes. This functionality and compact molecular designing of PTVE allowed a high formula-weight-based charging-discharging capacity per weight of 135 mAh g À1 , which has improved from those of conventional redox polymers, such as polyvinylferrocene À1 ) by our group. PTVE with a molecular weight of M n = 78 000 (M w /M n = 1.2) and unpaired electron content of 0.97 per monomer unit (a maximum effective charging-discharging capacity per weight of 131 mAh g À1 ) was prepared by the cationic polymerization of 2,2,6,6-tetramethylpiperidinyloxy vinylether 17 using trifluoroborane-diethylether as the initiator. The polymer was soluble in acetonitrile, but swollen and not soluble in water.w The acetonitrile solutions of PTVE (10-50 g/L) were spin-coated on a current collector such as a glassy carbon substrate, followed by drying at 80 1C for 24 h under vacuum, to yield the PTVE film with a thickness of 35 nm-1 mm, respectively. The cyclic voltammogram of the PTVE film repeatedly displayed a chemically reversible redox wave at 0.73 V vs. Ag/AgCl (Inset of Scheme 1 Redox couple of PTVE

Phase I clinical trial of the vaccination for the patients with metastatic melanoma using gp100-derived epitope peptide restricted to HLA-A*2402

<p>Abstract</p> <p>Background</p> <p>The tumor associated antigen (TAA) gp100 was one of the first identified and has been used in clinical trials to treat melanoma patients. However, the gp100 epitope peptide restricted to HLA-A*2402 has not been extensively examined clinically due to the ethnic variations. Since it is the most common HLA Class I allele in the Japanese population, we performed a phase I clinical trial of cancer vaccination using the HLA-A*2402 gp100 peptide to treat patients with metastatic melanoma.</p> <p>Methods</p> <p>The phase I clinical protocol to test a HLA-A*2402 gp100 peptide-based cancer vaccine was designed to evaluate safety as the primary endpoint and was approved by The University of Tokyo Institutional Review Board. Information related to the immunologic and antitumor responses were also collected as secondary endpoints. Patients that were HLA-A*2402 positive with stage IV melanoma were enrolled according to the criteria set by the protocol and immunized with a vaccine consisting of epitope peptide (VYFFLPDHL, gp100-in4) emulsified with incomplete Freund's adjuvant (IFA) for the total of 4 times with two week intervals. Prior to each vaccination, peripheral blood mononuclear cells (PBMCs) were separated from the blood and stored at -80°C. The stored PBMCs were thawed and examined for the frequency of the peptide specific T lymphocytes by IFN-γ- ELISPOT and MHC-Dextramer assays.</p> <p>Results</p> <p>No related adverse events greater than grade I were observed in the six patients enrolled in this study. No clinical responses were observed in the enrolled patients although vitiligo was observed after the vaccination in two patients. Promotion of peptide specific immune responses was observed in four patients with ELISPOT assay. Furthermore, a significant increase of CD8⁺gp100-in4⁺CTLs was observed in all patients using the MHC-Dextramer assay. Cytotoxic T lymphocytes (CTLs) clones specific to gp100-in4 were successfully established from the PBMC of some patients and these CTL clones were capable of lysing the melanoma cell line, 888 mel, which endogenously expresses HLA-restricted gp100-in4.</p> <p>Conclusion</p> <p>Our results suggest this HLA-restricted gp100-in4 peptide vaccination protocol was well-tolerated and can induce antigen-specific T-cell responses in multiple patients. Although no objective anti-tumor effects were observed, the effectiveness of this approach can be enhanced with the appropriate modifications.</p

First-year Sloan Digital Sky Survey-II (SDSS-II) Supernova Results: Hubble Diagram and Cosmological Parameters

We present measurements of the Hubble diagram for 103 Type Ia supernovae (SNe) with redshifts 0.04 < z < 0.42, discovered during the first season (Fall 2005) of the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. These data fill in the redshift "desert" between low- and high-redshift SN Ia surveys. We combine the SDSS-II measurements with new distance estimates for published SN data from the ESSENCE survey, the Supernova Legacy Survey, the Hubble Space Telescope, and a compilation of nearby SN Ia measurements. Combining the SN Hubble diagram with measurements of Baryon Acoustic Oscillations from the SDSS Luminous Red Galaxy sample and with CMB temperature anisotropy measurements from WMAP, we estimate the cosmological parameters w and Omega_M, assuming a spatially flat cosmological model (FwCDM) with constant dark energy equation of state parameter, w. For the FwCDM model and the combined sample of 288 SNe Ia, we find w = -0.76 +- 0.07(stat) +- 0.11(syst), Omega_M = 0.306 +- 0.019(stat) +- 0.023(syst) using MLCS2k2 and w = -0.96 +- 0.06(stat) +- 0.12(syst), Omega_M = 0.265 +- 0.016(stat) +- 0.025(syst) using the SALT-II fitter. We trace the discrepancy between these results to a difference in the rest-frame UV model combined with a different luminosity correction from color variations; these differences mostly affect the distance estimates for the SNLS and HST supernovae. We present detailed discussions of systematic errors for both light-curve methods and find that they both show data-model discrepancies in rest-frame $U$-band. For the SALT-II approach, we also see strong evidence for redshift-dependence of the color-luminosity parameter (beta). Restricting the analysis to the 136 SNe Ia in the Nearby+SDSS-II samples, we find much better agreement between the two analysis methods but with larger uncertainties.Comment: Accepted for publication by ApJ

The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations

The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 sq. deg. region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, Galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the Type Ia SNe, the main driver for the Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra. This paper describes the search algorithm and the software, and the real-time processing of the SDSS imaging data. We also present the details of the supernova candidate selection procedures and strategies for follow-up spectroscopic and imaging observations of the discovered sources.Comment: Accepted for publication in The Astronomical Journal (66 pages, 13 figures); typos correcte

Lymphocyte Apoptosis in HIV Infection

Human immunodeficiency virus (HIV-1) is the etiologic agent of acquired immunodeficiency syndrome (AIDS). Our understanding of the complexities of pathogenic mechanisms of HIV disease is still evolving; however, the mechanism whereby HIV-1 infection leads to profound depletion of CD4 T cells remains one of the central unsolved problems in AIDS research. In the past several years, there has been a dichotomy between virological and immunological viewpoints in understanding HIV-mediated cytopathicity, the former emphasizing killing of infected CD4 cells by HIV and the latter emphasizing indirect mechanisms wherein HIV or its soluble component(s) alter CD4 T-cell function and induce susceptibility to apoptosis

Correlation of Loss of CD4 T Cells with Plasma Levels of Both Soluble Form Fas (CD95) and Fas Ligand (FasL) in HIV-Infected Infants

Fas and Fas ligand (FasL), members of the TNFR and TNF families of molecules involved in apoptosis, respectively, are expressed in membrane-associated as well as soluble forms. Soluble Fas (sFas) and sFasL were evaluated in sequential samples from 16 HIV-infected and 11 HIV-exposed uninfected infants at ages 0–13 months. Regardless of the state of infection, age-dependent decreases in peripheral CD4 T cell counts and increases in sFas and sFasL were noted. However, decreases of the percentage CD4 T cells were more prominent in HIV-infected infants, and this was correlated significantly with increased plasma levels of sFas and sFasL (P = 0.002 and 0.004, respectively). Moreover, the levels of sFas in HIV-infected infants were found to be directly correlated with plasma HIV RNA (P = 0.03) and were significantly increased as early as age <1 month and prior to the onset of CD4 T cell decline. In uninfected infants, there was no such correlation between CD4 counts and the levels of sFas/sFasL. Plasma levels of sFas and sFasL may thus be important indicators of disease progression in perinatal HIV infection

Expressions of Fas (Cd95) and Fas Ligand in HIV Infected Individuals

To gain insights into mechanisms of accelerated lymphocyte apoptosis in HIV disease, we evaluated the expression of membrane bound Fas ligand (FasL) and Fas in PBMC and soluble forms of FasL (sFasL) and Fas (sFas) in plasma from HIV+ individuals and HIV− healthy volunteers. Surface FasL was detectable on monocytes, but poorly so on lymphocytes. Unexpectedly, monocytes expressed less FasL in HIV+ patients than in HIV− volunteers. Levels of sFasL in plasma of HIV+ individuals were elevated and correlated with plasma HIV RNA burden. Levels of sFas in plasma of HIV+subjects were also elevated and correlated with Fas expression in apoptotic lymphocytes. Finally, culture-induced lymphocyte apoptosis of HIV+ subjects was enhanced by anti-Fas agonistic Ab, but was not inhibited by anti-FasL blocking Abs. These results suggest that significant dysregulation of both Fas and FasL occurs in HIV infection, and that this contributes to increased sensitivity of lymphocytes to undergo apoptosis