New Possibility of Solving the Problem of Lifetime Ratio τ(Λb)/τ(Bd)\tau (\Lambda_b) / \tau (B_d)

We discuss the problem of the large discrepancy between the observed lifetime ratio of $\Lambda_b$ to $B_d$ and the theoretical prediction obtained by the heavy quark effective theory. A new possibility of solving this problem is proposed from the viewpoint of operator product expansion and the lifetime ratio of $\Omega_b$ to $B_d$ is predicted.Comment: LaTeX file (11 pages). The result is improved by including the 1/\Delta^3 order correction

Influence of water vapor on performance degradation and microstructural change of (La,Sr)(Co,Fe)O3-δ cathode

In this study, single cells employing a La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) cathode were operated with a supply of humidified oxygen to the cathode at 1000°C for 100 h to investigate the influence of water vapor on the performance and microstructure of LSCF cathode. When a gaseous mixture of 20% H2O−80% O2 was supplied to the cathode, the performance of LSCF cathode continuously lowered during a discharge at 300 mA cm−2 for 100 h. Then, the microstructures of surface and cross-section of LSCF cathode were observed by scanning electron microscopy. The surface morphology was drastically changed by the discharge operation. A SrO layer was formed at the outermost surface of cathode, indicating that the strontium segregation was accelerated by water vapor. In response to this phenomenon, the formation amount of cobalt- and/or iron-based oxides enlarged inside the electrode. These microstructural and phase changes would be responsible for the performance deterioration of LSCF cathode

Robustness of Clonogenic Assays as a Biomarker for Cancer Cell Radiosensitivity.

学位記番号：医博甲1854

Noncontact Monitoring of Vital Signs with RGB and Infrared Camera and Its Application to Screening of Potential Infection

In recent years, much attention is being paid to research and development of technology that provides noncontact measurement of vital signs, i.e., heart rate, respiration, and body temperature, which are important for understanding the state of a person’s health. As technology for sensing biological information has progressed, new biological measurement sensors have been developed successively. There have also been reports regarding methods for measuring respiration or heart rate using pressure sensors, microwave radar, air mattresses, or high-polymer piezoelectric film. The methods have wide-ranging applications, including systems for monitoring of elderly people, identification of sleep apnea, detection of patients suspected to have an infectious disease, and noncontact measurement of stress levels. In this chapter, the principles behind noncontact measurement of respiration and heartbeat using infrared/RGB facial-image analysis are discussed, along with the applications for such measurement in the detection of patients suspected to be suffering from infectious diseases

PROTON MODULATIONS ON THE IONIC CURRENTS IN RABBIT ATRIO-VENTRICULAR NODAL CELLS

Modulations of changing the extracellular pH on the electrophysiological activity of isolated rabbit atrio-ventricular (AV) nodal cells were investigated using the two microelectrode voltage-clamp technique. Increasing pH from 7.4 to 9.5 enhanced spontaneous activity. The action potential amplitude and the maximum rate of depolarization were decreased. The action potential duration at 50% repolarization and the cycle length were shortened. The maximum diastolic potential was hyperpolarized. The pH elevation increased the maximum conductances for both the slow inward current and the delayed outward current systems. In contrast, a decline of pH from 7.4 to 5.5 inhibited the activity and the ionic currents. The effects on the action potential parameters were reversed. However, both acidification and alkalinization failed to affect the gating kinetics of the channels. These results suggest that H⁺ would modulate the electrical activity of the AV nodal cells, due not to an alteration of the membrane surface charge, but to a direct protonation of the ionic channels

USE-DEPENDENT BLOCK AND RECOVERY OF NA⁺ CHANNELS BY CLASS IC ANTIARRHYTHMIC DRUGS (FLECAINIDE AND ETHACIZIN) IN CANINE VENTRICULAR MUSCLE

Electrophysiological effects of flecainide and ethacizin (class Ic antiarrhythmic drugs) were examined using conventional microelectrode techniques. Flecainide significantly depressed the maximum rate of depolarization (⩒max) at 3x10⁻⁶M, and depolarized the resting potential (RP) at 10⁻⁵M, in a concentration-dependent manner. Ethacizin depressed ⩒max at 10⁻⁶M, and depolarized RP at 10⁻⁵M, significantly. However, both drugs did not affect the effective refractory period (ERP) nor the action potential duration (75% repolarization, APD₇₅). Both also had no effect on the action potential amplitude (APA). On the other hand, the drugs caused a use (or rate)-dependent block of ⩒max, and their time constants of onset of inhibition (at 3 Hz) were slow ; 6.3±1.2　msec (n=10) in the presence of flecainide (10⁻⁵M), and 6.0±1.6 msec (n=6) in the presence of ethacizin (10⁻⁵M). The time constants of the recovery were also so late : 12.2±2.5 sec (n=3) for flecainide (10⁻⁵M), and 27.1±13.3 sec (n=3) for ethacizin (2x10⁻⁶M), These results indicate that both antiarrhythmic drugs, flecainide and ethacizin, have no effect on APD₇₅ and ERP, but possess the characteristics for very slow kinetics of the use-dependent block and the recovery for fast Na⁺ channels of cardiac muscles. Ethacizin produces slower kinetics for the Na⁺ channels than flecainide

Expression profiles of urbilaterian genes uniquely shared between honey bee and vertebrates

<p>Abstract</p> <p>Background</p> <p>Large-scale comparison of metazoan genomes has revealed that a significant fraction of genes of the last common ancestor of Bilateria (Urbilateria) is lost in each animal lineage. This event could be one of the underlying mechanisms involved in generating metazoan diversity. However, the present functions of these ancient genes have not been addressed extensively. To understand the functions and evolutionary mechanisms of such ancient Urbilaterian genes, we carried out comprehensive expression profile analysis of genes shared between vertebrates and honey bees but not with the other sequenced ecdysozoan genomes (honey bee-vertebrate specific, HVS genes) as a model.</p> <p>Results</p> <p>We identified 30 honey bee and 55 mouse HVS genes. Many HVS genes exhibited tissue-selective expression patterns; intriguingly, the expression of 60% of honey bee HVS genes was found to be brain enriched, and 24% of mouse HVS genes were highly expressed in either or both the brain and testis. Moreover, a minimum of 38% of mouse HVS genes demonstrated neuron-enriched expression patterns, and 62% of them exhibited expression in selective brain areas, particularly the forebrain and cerebellum. Furthermore, gene ontology (GO) analysis of HVS genes predicted that 35% of genes are associated with DNA transcription and RNA processing.</p> <p>Conclusion</p> <p>These results suggest that HVS genes include genes that are biased towards expression in the brain and gonads. They also demonstrate that at least some of Urbilaterian genes retained in the specific animal lineage may be selectively maintained to support the species-specific phenotypes.</p

High sensitivity of an ELISA kit for detection of the gamma-isoform of 14-3-3 proteins: usefulness in laboratory diagnosis of human prion disease

<p>Abstract</p> <p>Background</p> <p>The gamma-isoform of the 14-3-3 protein (14-3-3 gamma) is expressed in neurons, and could be a specific marker for neuronal damage. This protein has been reported as a detectable biomarker, especially in the cerebrospinal fluid (CSF) of Creutzfeldt-Jakob disease (CJD) patients by Western blotting (WB) or enzyme-linked immunosorbent assays (ELISAs). Western blotting for 14-3-3 gamma is not sensitive, and the reported data are conflicting among publications. An ELISA specific for 14-3-3 gamma is not available.</p> <p>Methods</p> <p>CJD patients (n = 114 sporadic CJD patients, 7 genetic CJD, and 3 iatrogenic CJD) and 99 patients with other neurodegenerative diseases were examined in this study. The CSF samples obtained were analyzed by Western blotting for 14-3-3 gamma, and by ELISA for total tau protein. We evaluated the sensitivity and specificity of the newly developed sandwich ELISA for 14-3-3 gamma.</p> <p>Results</p> <p>The cut-off value of the 14-3-3 gamma ELISA was > 1, 683 AU/ml; and sensitivity was 95.2%, with 72.7% specificity. This specificity was the same for the total tau protein ELISA. Seven CJD cases were negative by WB but positive using the 14-3-3 gamma ELISA, indicating that the ELISA is more sensitive. All 21 cases of early stage CJD could be diagnosed using a combination of the 14-3-3γ ELISA and diffusion weighted MR imaging (DWI-MRI).</p> <p>Conclusion</p> <p>The 14-3-3 gamma ELISA was more sensitive than conventional WB, and was useful for laboratory diagnosis of CJD, similar to the ELISA for the tau protein. Using DWI-MRI and these ELISA tests on CSF, diagnosis of CJD will be possible even at early stages of the disease.</p