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Showing papers by "Tokyo University of Science published in 2005"


Journal ArticleDOI
Piero Carninci, Takeya Kasukawa1, Shintaro Katayama, Julian Gough  +194 moreInstitutions (36)
02 Sep 2005-Science
TL;DR: Detailed polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.
Abstract: This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

3,412 citations



Journal ArticleDOI
TL;DR: In this article, the dielectric, ferroelectric and piezoelectric properties of perovskite and bismuth layer-structured BLSF (BLSF) ceramics are described as superior candidates for lead-free, lead free, and low-cost piezolectric materials to reduce environmental damages.
Abstract: Dielectric, ferroelectric and piezoelectric properties of perovskite ferroelectric and bismuth layer-structured ferroelectric (BLSF) ceramics are described as superior candidates for lead-free piezoelectric materials to reduce environmental damages. Perovskite type ceramics seem to be suitable for actuator and high power applications that are required a large piezoelectric constant, d 33 (>300 pC/N) and a high Curie temperature, T c (>200 °C). For BaTiO 3 (BT)-based solid solutions, that is, (1 − x )BaTiO 3 − x (Bi 0.5 K 0.5 )TiO 3 [BTBK − 100 x ] ceramics, the T c increases with increasing the amount of x . BTBK-20 + MnCO 3 0.1 wt.% ceramic shows the high T c than 200 °C and the electromechanical coupling factor, k 33 = 0.35. In the case of a (Bi 1/2 Na 1/2 )TiO 3 − b BaTiO 3 − c (Bi 1/2 K 1/2 )TiO 3 [BNBK (100 a /100 b /100 c )] solid solution ceramics, the d 33 and T c are 191 pC/N and 301 °C for the BNBK (85.2/2.8/12), respectively. On the other hand, BLSF ceramics seem to be excellent candidates as piezoelectric sensors for high temperatures and ceramic resonators with high mechanical quality factor ( Q m ), and low temperature coefficient of resonance frequency (TC- f r ). Donor-doped Bi 4 Ti 3 O 12 ceramics such as Bi 4 Ti 3− x Nb x O 12 [BITN- x ] and Bi 4 Ti 3− x V x O 12 [BITV- x ] show high T c than 650 °C. The k 33 value of the grain-oriented (HF) BITN-0.08 ceramic is 0.39 and is able to keep the same value up to 350 °C. Bi 3 TiTaO 9 (BTT)-based solid solution system, Sr x −1 Bi 4− x Ti 2− x Ta x O 9 [SBTT2( x )] (1 ≦ x ≦ 2), displays the high Q m value (=13500) in (p)-mode at the x = 1.25 composition.

742 citations


Journal ArticleDOI
TL;DR: Cell sheet engineering allows for tissue regeneration by either direct transplantation of cell sheets to host tissues or the creation of three-dimensional structures via the layering of individual cell sheets.

599 citations


Journal ArticleDOI
TL;DR: A novel photoluminescent ink for rewritable media that dichroically emits phosphorescence due to a structural bistability of the self-assembled luminophor is reported, which can provide an important step towards the next-generation security technology for information handling.
Abstract: Security inks have become of increasing importance. They are composed of invisible substances that provide printed images that are not able to be photocopied, and are readable only under special environments. Here we report a novel photoluminescent ink for rewritable media that dichroically emits phosphorescence due to a structural bistability of the self-assembled luminophor. Long-lasting images have been developed by using conventional thermal printers, which are readable only on exposure to ultraviolet light, and more importantly, are thermally erasable for rewriting. Although thermally rewritable printing media have already been developed using visible dyes and cholesteric liquid crystals, security inks that allow rewriting of invisible printed images are unprecedented. We realized this unique feature by the control of kinetic and thermodynamic processes that compete with one another in the self-assembly of the luminophor. This strategy can provide an important step towards the next-generation security technology for information handling.

516 citations


Journal ArticleDOI
TL;DR: The remarkably enhanced gene silencing in hepatoma cells was achieved by assembling lactosylated-PEG-siRNA conjugates bearing acid-labile beta-thiopropionate linkages into polyion complex micelles through the mixing with poly(l-lysine).
Abstract: The remarkably enhanced gene silencing in hepatoma cells was achieved by assembling lactosylated-PEG−siRNA conjugates bearing acid-labile β-thiopropionate linkages into polyion complex (PIC) micelles through the mixing with poly(l-lysine). The PIC micelles with clustered lactose moieties on the periphery were successfully transported into hepatoma cells in a receptor-mediated manner, releasing hundreds of active siRNA molecules into the cellular interior responding to the pH decrease in the endosomal compartment. Eventually, almost 100 times enhancement in gene silencing activity compared to that of the free conjugate was achieved for the micelle system, facilitating the practical utility of siRNA therapeutics.

478 citations



Book
03 Jun 2005
TL;DR: The application of bearingless drives is emerging as an important technique in the areas of high-speed machinery and motion control, and a thorough grounding in the principles behind this cutting-edge technology is provided in this article.
Abstract: The application of bearingless drives is emerging as an important technique in the areas of high-speed machinery and motion-control, and this book aims to provide a thorough grounding in the principles behind this cutting-edge technology. Basic principles are described in detail with practical examples to aid understanding, and the different types of bearingless drives are introduced, along with coverage of test machines and applications.Aimed at practising electrical and mechanical engineers and advanced students, Magnetic Bearings and Bearingless Drives provides an essential guide to an area of engineering previously only fully covered by large numbers of academic papers. Key Features : Unique and comprehensive coverage of a cutting-edge subject for electrical and mechanical engineers A reference text and survey for designers, manufacturers and users of high-speed motors, generators and electrical drive systems Examines the basic principles behind magnetic bearings, with key technologies and applications illustrated through examples and case studies

464 citations


Journal ArticleDOI
TL;DR: These organogels undergo gel-to-sol transition due to the destabilization of the metallophilic interactions, where the red luminescent of the nondoped system becomes hardly visible, while the blue luminescence of the Ag(+)-doped system turns green.
Abstract: A trinuclear Au(I) pyrazolate complex bearing long alkyl chains (1) in hexane self-assembles via a Au(I)−Au(I) metallophilic interaction, to form a red-luminescent organogel (λem = 640 nm, λext = 284 nm). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of an air-dried gel with 1 show the presence of heavily entangled fibers, each consisting of a rectangularly packed columnar assembly of 1. Doping of the organogel with a small amount of Ag+ results in a blue luminescence (λem = 458 nm, λext = 370 nm) without disruption of the gel, while removal of doped Ag+ with cetyltrimethylammonium chloride results in complete recovery of the original red-luminescent gel. Upon heating, these organogels undergo gel-to-sol transition due to the destabilization of the metallophilic interactions, where the red luminescence of the nondoped system becomes hardly visible, while the blue luminescence of the Ag+-doped system turns green (λem = 501 nm, λext = 370 nm). On cooling, these solutions undergo ge...

397 citations


Journal ArticleDOI
E. Aliu1, S. Andringa1, Shigeki Aoki2, J. Argyriades  +156 moreInstitutions (28)
TL;DR: The energy-dependent disappearance of nu(mu), which the authors presume have oscillated to nu(tau), is observed in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment.
Abstract: We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).

385 citations


Journal ArticleDOI
TL;DR: This study is the first to yield evidence that OATP1B1 is involved in the hepatic disposition of SN-38 and that genetic polymorphisms of O ATP1 B1 may contribute to the known interpatient variability in disposition of irinotecan.
Abstract: Irinotecan hydrochloride (CPT-11) is a potent anticancer drug that is converted to its active metabolite, 7-ethyl-10-hydroxycamptothecin (SN-38), and other metabolites in liver. The disposition and gastrointestinal toxicity of irinotecan exhibit a wide interpatient variability. Here, we examined the contribution of an organic anion-transporting polypeptide, OATP1B1 (OATP-C), which transports a variety of drugs and their metabolites from blood to liver in humans, to the hepatic disposition of irinotecan, SN-38, and its glucuronide conjugate (SN-38G) by using HEK293 cells stably transfected with SLCO1B1*1a (OATP-C*1a) coding wild-type OATP1B1. We further examined the effect of single nucleotide polymorphisms in OATP1B1 by measuring uptake activity in Xenopus oocytes expressing OATP1B1*1a and three common variants. In all cases, transport activity for SN-38 was observed, whereas irinotecan and SN-38G were not transported. Moreover, SN-38 exhibited a significant inhibitory effect on OATP1B1-mediated uptake of [(3)H]estrone-3-sulfate. Among the variants examined, OATP1B1*15 (N130D and V174A; reported allele frequency 10-15%) exhibited decreased transport activities for SN-38 as well as pravastatin, estrone-3-sulfate, and estradiol-17beta-glucuronide. This study is the first to yield evidence that OATP1B1 is involved in the hepatic disposition of SN-38 and that genetic polymorphisms of OATP1B1 may contribute to the known interpatient variability in disposition of irinotecan.

Journal ArticleDOI
TL;DR: In this paper, the authors study the evolution of a supernova core from the beginning of the gravitational collapse of a 15 M☉ star up to 1 s after core bounce and compare two sets of EOS, namely, those by Lattimer and Swesty (LS-EOS) and by Shen et al. (SH-Eos).
Abstract: We study the evolution of a supernova core from the beginning of the gravitational collapse of a 15 M☉ star up to 1 s after core bounce. We present results of spherically symmetric simulations of core-collapse supernovae by solving general relativistic ν-radiation hydrodynamics in the implicit time differencing. We aim to explore the evolution of shock waves in the long term and investigate the formation of proto-neutron stars together with supernova neutrino signatures. These studies are done to examine the influence of the equation of state (EOS) on the postbounce evolution of shock waves in the late phase and the resulting thermal evolution of proto-neutron stars. We compare two sets of EOSs, namely, those by Lattimer and Swesty (LS-EOS) and by Shen et al. (SH-EOS). We found that, for both EOSs, the core does not explode and the shock wave stalls similarly in the first 100 ms after bounce. A revival of the shock wave does not occur even after a long period in either case. However, the recession of the shock wave appears different beyond 200 ms after bounce, having different thermal evolution of the central core. A more compact proto-neutron star is found for LS-EOS than SH-EOS with a difference in the central density by a factor of ~2 and a difference of ~10 MeV in the peak temperature. The resulting spectra of supernova neutrinos are different to an extent that may be detectable by terrestrial neutrino detectors.



Journal ArticleDOI
TL;DR: It is shown that FcɛRI stimulation triggers the formation of microtubules in a manner independent of calcium, and that the Fyn/Gab2/RhoA (but not Lyn/SLP-76) signaling pathway plays a critical role in the calcium-independent microtubule-dependent pathway.
Abstract: The aggregation of high affinity IgE receptors (Fcepsilon receptor I [FcepsilonRI]) on mast cells is potent stimulus for the release of inflammatory and allergic mediators from cytoplasmic granules. However, the molecular mechanism of degranulation has not yet been established. It is still unclear how FcepsilonRI-mediated signal transduction ultimately regulates the reorganization of the cytoskeleton and how these events lead to degranulation. Here, we show that FcepsilonRI stimulation triggers the formation of microtubules in a manner independent of calcium. Drugs affecting microtubule dynamics effectively suppressed the FcepsilonRI-mediated translocation of granules to the plasma membrane and degranulation. Furthermore, the translocation of granules to the plasma membrane occurred in a calcium-independent manner, but the release of mediators and granule-plasma membrane fusion were completely dependent on calcium. Thus, the degranulation process can be dissected into two events: the calcium-independent microtubule-dependent translocation of granules to the plasma membrane and calcium-dependent membrane fusion and exocytosis. Finally, we show that the Fyn/Gab2/RhoA (but not Lyn/SLP-76) signaling pathway plays a critical role in the calcium-independent microtubule-dependent pathway.

Journal ArticleDOI
TL;DR: In this paper, the authors study the evolution of supernova core from the beginning of gravitational collapse of a 15Msolar star up to 1 second after core bounce and examine the influence of equation of state (EOS) on the postbounce evolution of shock wave in the late phase and the resulting thermal evolution of protoneutron star.
Abstract: We study the evolution of supernova core from the beginning of gravitational collapse of a 15Msolar star up to 1 second after core bounce. We present results of spherically symmetric simulations of core-collapse supernovae by solving general relativistic neutrino-radiation-hydrodynamics in the implicit time-differencing. We aim to explore the evolution of shock wave in a long term and investigate the formation of protoneutron star together with supernova neutrino signatures. These studies are done to examine the influence of equation of state (EOS) on the postbounce evolution of shock wave in the late phase and the resulting thermal evolution of protoneutron star. We make a comparison of two sets of EOS, that is, by Lattimer and Swesty (LS-EOS) and by Shen et al.(SH-EOS). We found that, for both EOSs, the core does not explode and the shock wave stalls similarly in the first 100 milliseconds after bounce. The revival of shock wave does not occur even after a long period in either cases. However, the recession of shock wave appears different beyond 200 milliseconds after bounce, having different thermal evolution of central core. A more compact protoneutron star is found for LS-EOS than SH-EOS with a difference in the central density by a factor of ~2 and a difference of ~10 MeV in the peak temperature. Resulting spectra of supernova neutrinos are different to the extent that may be detectable by terrestrial neutrino detectors.

Journal ArticleDOI
TL;DR: It is proposed that poly(I:C) is a new effective intranasal adjuvant for influenza virus vaccine.
Abstract: The mucosal adjuvant effect of synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid [poly(I:C)] against influenza virus was examined under intranasal coadministration with inactivated hemagglutinin (HA) vaccine in BALB/c mice and was shown to have a protective effect against both nasal-restricted infection and lethal lung infection. Intranasal administration of vaccine from PR8 (H1N1) with poly(I:C) induced a high anti-HA immunoglobulin A (IgA) response in the nasal wash and IgG antibody response in the serum, while vaccination without poly(I:C) induced little response. Intracerebral injection confirmed the safety of poly(I:C). In addition, we demonstrated that administration of poly(I:C) with either A/Beijing (H1N1) or A/Yamagata (H1N1) vaccine conferred complete protection against PR8 challenge in this mouse nasal infection model, suggesting that poly(I:C) possessed cross-protection ability against variant viruses. To investigate the mechanism of the protective effect of poly(I:C), mRNA levels of Toll-like receptors and cytokines were examined in the nasal-associated lymphoid tissue after vaccination or virus challenge. Intranasal administration of HA vaccine with poly(I:C) up-regulated expression of Toll-like receptor 3 and alpha/beta interferons as well as Th1- and Th2-related cytokines. We propose that poly(I:C) is a new effective intranasal adjuvant for influenza virus vaccine.

Journal ArticleDOI
TL;DR: It is shown that postoperative adjuvant chemotherapy with UFT was associated with improved 5- and 7-year survival in a Japanese patient population composed primarily of stage I adenocarcinoma patients.
Abstract: Purpose Recent clinical trials have shown the efficacy of platinum-based adjuvant chemotherapy for completely resected non–small-cell lung cancer (NSCLC). In Japan, many clinical trials of adjuvant chemotherapy with tegafur-uracil (UFT) have been conducted, and some trials showed positive results while others showed negative results. Thus, we performed a meta-analysis to assess the efficacy of postoperative adjuvant chemotherapy with UFT in NSCLC. Methods Among nine trials of postoperative adjuvant UFT-containing chemotherapy, six trials comparing surgery alone with surgery plus UFT were identified. Of six trials, two were three-arm trials including cisplatin-based chemotherapy followed by UFT, and data from that arm were not included in the meta-analysis. Results Of 2,003 eligible patients, most (98.8%) had squamous cell carcinoma or adenocarcinoma, and most had stage I disease; the tumor classification was T1 in 1,308 (65.3%), T2 in 674 (33.6%), and the nodal status was N0 in 1,923 (96.0%). The two trea...

Journal ArticleDOI
TL;DR: The results suggest that L. casei prevented atypia of colorectal tumors in men and women presently free from tumor and in women who had had at least 2 coloreCTal tumors removed.
Abstract: The epidemiologic evidence that dietary fiber protects against colorectal cancer is equivocal. No large-scale clinical study of the administration of Lactobacillus casei has been reported. We examined whether dietary fiber and L. casei prevented the occurrence of colorectal tumors. Subjects were 398 men and women presently free from tumor who had had at least 2 colorectal tumors removed. Subjects were randomly assigned to 4 groups administered wheat bran, L. casei, both or neither. The primary end point was the presence or absence of new colorectal tumor(s) diagnosed by colonoscopy after 2 and 4 years. Among 380 subjects who completed the study, 95, 96, 96 and 93 were assigned to the wheat bran, L. casei, both and no treatment groups, respectively. Multivariate adjusted ORs for occurrence of tumors were 1.31 (95% CI 0.87–1.98) in the wheat bran group and 0.76 (0.50–1.15) in the L. casei group compared to the control group. There was a significantly higher number of large tumors after 4 years in the wheat bran group. The occurrence rate of tumors with a grade of moderate atypia or higher was significantly lower in the group administered L. casei. No significant difference in the development of new colorectal tumors was observed with administration of either wheat bran or L. casei. However, our results suggest that L. casei prevented atypia of colorectal tumors. ' 2005 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: The results suggested the capacity for selective adsorption of MIPi to be not only based on the isoelectric point (pI) and protein molecular weight, but also the characteristics of protein recognition cavities imprinted on base silica.

Journal ArticleDOI
TL;DR: Diffuse reflection and photoluminescence spectra of the solid solutions shifted monotonically to a long wavelength side, as the ratio of CuInS(2) to ZnS increased in theSolid solutions, and the photocatalytic H( 2) evolution depended on the composition as well as the photophysical properties.
Abstract: (CuIn)xZn2(1-x)S2 solid solutions between a ZnS photocatalyst with a wide band gap and CuInS2 with a narrow band gap showed photocatalytic activities for H2 evolution from aqueous solutions containing sacrificial reagents SO32- and S2- under visible-light irradiation (λ ≥ 420 nm). Pt (0.5 wt %)-loaded (CuIn)0.09Zn1.82S2 with a 2.3-eV band gap showed the highest activity for H2 evolution, and the apparent quantum yield at 420 nm amounted to 12.5%. H2 evolved at a rate of 1.5 L h-1 m-2 under irradiation with a solar simulator (AM 1.5). Diffuse reflection and photoluminescence spectra of the solid solutions shifted monotonically to a long wavelength side, as the ratio of CuInS2 to ZnS increased in the solid solutions. The photocatalytic H2 evolution depended on the composition as well as the photophysical properties. DFT calculations suggested that the visible-light response should be derived from the contribution of Cu 3d and S 3p orbitals to the valence band and that of In 5s5p and Zn 4s4p orbitals to the ...

Journal ArticleDOI
TL;DR: Carbon nanoparticles modified with a polypyrrole (PPy) film, impregnated with a solution of a cobalt salt, and heat-treated under an inert atmosphere at 600−700 °C are a good electrocatalyst for the four-electron reduction of O2.
Abstract: Carbon nanoparticles modified with a polypyrrole (PPy) film, impregnated with a solution of a cobalt salt, and heat-treated under an inert atmosphere at 600−700 °C are a good electrocatalyst for the four-electron reduction of O2.

Journal ArticleDOI
TL;DR: The unprecedented example of asymmetric autocatalysis triggered directly by a chiral physical factor, that is, right- and left-handed CPL, leading to a near enantiopure compound is found.
Abstract: Right- and left-handed circularly polarized light (CPL) has been proposed as one of the origins of homochirality of biomolecules. However, the enantiomeric excess induced by CPL has been only very low ( 99.5% ee. On the other hand, irradiation with l-CPL affords (S)-pyrimidyl alkanol with >99.5% ee. Thus, chiral physical power, such as CPL, in conjunction with asymmetric autocatalysis, provides a highly enantioenriched compound.

Journal ArticleDOI
TL;DR: In this paper, a low-temperature synthesis technique in the presence of cationic surfactant was used to extract mesoporous titania particles from transmission electron microscopy images.
Abstract: In this study, we demonstrate a novel method for preparing crystallized mesoporous titania by using a low-temperature synthesis technique in the presence of cationic surfactant. XRD patterns showed that the titania particles obtained had both hexagonal structure and a wall with anatase crystalline structure. Transmission electron microscopy (TEM) observation and corresponding electron diffraction pattern confirmed that the calcined particles are crystallized mesoporous titania.

Journal ArticleDOI
TL;DR: In this paper, a hollow fiber with a pressure gradient was used to compress femtosecond laser pulses spectrally broadened by self-phase modulation, allowing an increase of the pulse energy for pulse compression.
Abstract: We propose and demonstrate a pulse compression technique using a hollow fiber with a pressure gradient. This technique improves the spatial and spectral qualities of femtosecond laser pulses spectrally broadened by self-phase modulation, and allows an increase of the pulse energy for pulse compression. Using chirped mirrors for dispersion compensation, we have successfully compressed the pulse to less than 10 fs with an energy as high as 5 mJ.

Book ChapterDOI
TL;DR: In this paper, a continual effort on generalization of the Trotter formula to higher-order exponential product formulas is reviewed, particularly because it conserves important symmetries of the system dynamics.
Abstract: In the present article, we review a continual effort on generalization of the Trotter formula to higher-order exponential product formulas. The exponential product formula is a good and useful approximant, particularly because it conserves important symmetries of the system dynamics. We focuse on two algorithms of constructing higher-order exponential product formulas. The first is the fractal decomposition, where we construct higher-order formulas recursively. The second is to make use of the quantum analysis, where we compute higher-order correction terms directly. As interludes, we also have described the decomposition of symplectic integrators, the approximation of time-ordered exponentials, and the perturbational composition.

Journal ArticleDOI
TL;DR: IL-27 efficiently induces Th1 differentiation under Th1-polarizing conditions, but without IL-12, and that the rapid up-regulation of ICAM-1 expression on naive CD4+ T cells is important for the IL-27-induced Th 1 differentiation.
Abstract: IL-27 is a novel IL-6/IL-12 family cytokine that is considered to play a role in Th1 differentiation, whereas the exact role of IL-27 in Th1 differentiation and its molecular mechanism remain unclear. In this study we demonstrate a role for IL-27 in the early regulation of Th1 differentiation and its possible molecular mechanism. The ability of IL-27 to induce Th1 differentiation was most prominent under Th1-polarizing conditions, but without IL-12 in a STAT4- and IFN-gamma-independent manner, and was overruled by IL-12 dose dependently. IL-27 rapidly up-regulated the expression of ICAM-1 on naive CD4+ T cells, but not on APCs, and blocking Abs against ICAM-1 and LFA-1 inhibited the IL-27-induced Th1 differentiation. Although IL-27 augmented T-bet expression in naive CD4+ T cells as previously reported, T-bet was not necessary for the IL-27-induced rapid up-regulation of ICAM-1 expression and Th1 differentiation. In contrast, STAT1 was revealed to be required for the rapid up-regulation of ICAM-1 expression and Th1 differentiation by directly mediating the transcriptional enhancement of ICAM-1 gene expression. These results indicate that IL-27 efficiently induces Th1 differentiation under Th1-polarizing conditions, but without IL-12, and that the rapid up-regulation of ICAM-1 expression on naive CD4+ T cells is important for the IL-27-induced Th1 differentiation. Considering that IL-27 is produced from macrophages and DCs earlier than IL-12, the present results suggest that IL-27 may play a pivotal role in early efficient induction of Th1 differentiation until sufficient IL-12 is produced.

Journal ArticleDOI
TL;DR: A reactive poly(ethylene glycol) (PEG)-brushed layer was constructed on a surface plasmon resonance (SPR) sensor chip using a heterobifunctional PEG possessing an acetal group at one end and a mercapto group at the other end, allowing dramatic reduction of nonspecific protein adsorption.
Abstract: A reactive poly(ethylene glycol) (PEG)-brushed layer was constructed on a surface plasmon resonance (SPR) sensor chip using a heterobifunctional PEG possessing an acetal group at one end and a mercapto group at the other end (α-acetal-ω-mercapto-PEG). The density of the PEG brushed layer substantially increased with repetitive adsorption/rinse cycles of the PEG on the sensor chip, allowing dramatic reduction of nonspecific protein adsorption. Notably, formation of a short, filler layer of PEG (2 kDa) in the preconstructed longer PEG brushed layer (5 kDa) achieved almost complete prevention of nonspecific protein adsorption. The acetal group located at the distal end of the tethered PEG was converted to an aldehyde group by the acid treatment, followed by the installation of biocytin hydrazide through Schiff base formation. SPR sensing of streptavidin was done with a very high S/N ratio even in a proteinous medium using the biotinylated PEG (5 kDa) tethered chip with an inert filler layer of short PEG (2 k...

Journal ArticleDOI
TL;DR: Asymmetric intramolecular Michael reaction catalyzed by an organocatalyst derived from cysteine has been developed for the synthesis of chiral bicyclo and cis-disubstituted cyclopentane skeletons with a creation of three or two contiguous chiral centers in good yield with high diastereo- and excellent enantioselectivities.
Abstract: Asymmetric intramolecular Michael reaction catalyzed by an organocatalyst derived from cysteine has been developed for the synthesis of chiral bicyclo[4.3.0]nonene and cis-disubstituted cyclopentane skeletons with a creation of three or two contiguous chiral centers in good yield with high diastereo- and excellent enantioselectivities.

Journal ArticleDOI
TL;DR: In this paper, an apparent rate constant (kapproximation) for the oxygen reduction reaction (orr) was evaluated from the hydrodynamic voltammograms by correcting the oxygen concentration in the electrolyte solution.