Synthesis of [60]fullerene adducts bearing carbazole moieties by Bingel reaction and their properties

Carbazole-linked [60]fullerene adducts were successfully prepared by the Bingel reactions using carbazole derivatives bearing one or two ethyl malonate moieties. In the latter cases, specific bisadduct regioisomers were obtained, depending on the spacer unit between two ethyl malonate moieties. [reaction: see text]     

Resveratrol derivatives from Upuna borneensis

Four new resveratrol derivatives, upunaphenols B (1), C (4), D (5) (resveratrol tetramer) and E (6, resveratrol dimer with a C6-C1 unit), together with nine known resveratrol oligomers and resveratrol were isolated from an acetone soluble part of stem of Upuna borneensis (Dipterocarpaceae). The structures of new compounds were determined by spectral analysis including 1D and 2D NMR experiments.     

Ultrastable cesium atomic clock with a 9.1926-GHz regeneratively mode-locked fiber laser

We describe an ultrastable cesium (Cs) atomic clock with a 9.1926-GHz regeneratively mode-locked fiber laser obtained by use of an optically pumped Cs beam tube. By adopting a 1-m-long Cs beam tube with a linewidth of 110 Hz, we have successfully obtained frequency stabilities of 4.8 x 10(-12) for tau = 1 s and 6.3 x 10(-13) for tau = 50 s for a 9.1926-GHz microwave output signal. This Cs atomic clock can generate an optical pulse train with the same stability as that of the obtained microwave, which allows us to deliver a frequency standard optical signal throughout the world by means of optical fiber networks.     

A Respiratory Movement Monitoring System Using Fiber-Grating Vision Sensor for Diagnosing Sleep Apnea Syndrome

A non-restrictive and non-contact respiratory movement monitoring system that finds the boundary between chest and abdomen automatically and detects the vertical movement of each part of the body separately is proposed. The system uses a fiber-grating vision sensor technique and the boundary position detection is carried out by calculating the centers of gravity of upward moving and downward moving sampling points, respectively. In the experiment to evaluate the ability to detect the respiratory movement signals of each part and to discriminate between obstructive and central apneas, detected signals of the two parts and their total clearly showed the peculiarities of obstructive and central apnea. The cross talk between the two categories classified automatically according to several rules that reflect the peculiarities was 15%. This result is sufficient for discriminating central sleep apnea syndrome from obstructive sleep apnea syndrome and indicates that the system is promising as screening equipment. © 2005 The Optical Society of Japan     

Block copolymer-templated chemistry on Si, Ge, InP, and GaAs surfaces

Patterning of semiconductor surfaces is an area of intense interest, not only for technological applications, such as molecular electronics, sensing, cellular recognition, and others, but also for fundamental understanding of surface reactivity, general control over surface properties, and development of new surface reactivity. In this communication, we describe the use of self-assembling block copolymers to direct semiconductor surface chemistry in a spatially defined manner, on the nanoscale. The proof-of-principle class of reactions evaluated here is galvanic displacement, in which a metal ion, M+, is reduced to M0 by the semiconductor, including Si, Ge, InP, and GaAs. The block copolymer chosen has a polypyridine block which binds to the metal ions and brings them into close proximity with the surface, at which point they undergo reaction; the pattern of resulting surface chemistry, therefore, mirrors the nanoscale structure of the parent block copolymer. This chemistry has the added advantage of forming metal nanostructures that result in an alloy or intermetallic at the interface, leading to strongly bound metal nanoparticles that may have interesting electronic properties. This approach has been shown to be very general, functioning on a variety of semiconductor substrates for both silver and gold deposition, and is being extended to organic and inorganic reactions on a variety of conducting, semiconducting, and insulating substrates.     

2JC,H index: a nondestructive NMR method for differentiation of aldohexopyranosyl residues

A new 2J(C,H) index method is described for identification of aldohexopyranose. This method is based on a fact that 2J(C,H) values reflect the stereochemistry for glycol connectivity. Based on the observed 2J(C,H) values for galactose, glucose, and mannose, 2J(C,H) profiles for other aldohexopyranoses are proposed. A combination of 2J(C,H) values was found to be useful for identification of aldohexopyranosyl residues in glycans. [structure: see text]     

Search for the decay KL --> pi(0)e+e-

We report on a search for the decay KL-->pi(0)e+e- carried out by the KTeV/E799 experiment at Fermilab. This decay is expected to have a significant CP violating contribution and the measurement of its branching ratio could support the Cabibbo-Kobayashi-Maskawa mechanism for CP violation or could point to new physics. Two events were observed in the 1997 data with an expected background of 1.06+/-0.41 events, and we set an upper limit B(KL-->pi(0)e+e-)<5.1 x 10(-10) at the 90% confidence level.     

Study of the K(0)(L) --> pi(+)pi(-)gamma Direct Emission Vertex

We have performed studies of the K(0)(L)-->pi(+)pi(-)gamma direct emission ( DE) and inner Bremsstrahlung ( IB) vertices, based on data collected by KTeV during the 1996 Fermilab fixed target run. We find a(1)/a(2) = -0.737+/-0.034 GeV2 for the DE form-factor parameter in the rho-propagator parametrization, and report on fits of the form factor to linear and quadratic functions as well. We concurrently measure gamma(K(0)(L)-->pi(+)pi(-)gamma,E(*)(gamma)>20 MeV)/gamma(K(0)(L)-->pi(+)pi(-)) = (20.8+/-0.3)x10(-3), and a K(0)(L)-->pi(+)pi(-)gamma DE/(DE+IB) branching ratio of 0.683+/-0.011.