Edge states of Sr2_2RuO4_4 detected by in-plane tunneling spectroscopy

We perform tunneling spectroscopy of Sr$_2$RuO$_4$ searching for the edge states peculiar to topological superconductivity. Conductance spectra obtained on Sr$_2$RuO$_4$/Au junctions fabricated using $in$ $situ$ process show broad humps indicating the successful detection of a-axis edge of 1.5K phase. Three types of peak shape are detected: domelike peak, split peak and two-step peak. By comparing the experiments with predictions for unconventional superconductivity, these varieties are shown to originate from multiband chiral p-wave symmetry with weak anisotropy of pair amplitude. The broad hump in conductance spectrum is a direct manifestation of the edge state peculiar to the chiral p-wave superconductivity.Comment: 7 pages and 4 figure

The effects of Cigarette Smoking on the human VEP (Visual Evoked Potential) and EEG

The effects of cigarette smoking on the human CNS (Central Nervous System) were studied by VEP (Visual Evoked Potential) with 38 healthy male subjects (20～42 y. o., mean : 18. 6 cig./ day×8. 5 years). All subjects were deprived of smoking from the last night prior to the expriment. In the experimental session the subjects were asked to smoke two cigarettes (nicotine content 2. 7 mg/ cig.) in ten minutes after control recording. EEGs containing VEPs evoked by flash stimuli once every 5 second were recorded into the magnetic tape through the two derivations (2CH : O1→A1+2 and 5CH : O1→Cz) together with EEGs also through four other derivations, simultaneously. Reproducing the tape, VEPs from the two derivations were recorded, with 1000 msec of analysis time, for each recording session ; before, during and 10, 20, 30 min. after cigarette smoking. The EEGs were subjected to the quantitative frequency analysis. VEPs were converted into a series of numbers and subjected to the computer processing and statistical assessment with special reference to the EEG changes. The subjects were divied into the two groups, heavy smoker group and light smoker group (more than/within 15 cig./ day), for further study. The following results were obtained. 1. In the waveforms of group mean VEP recorded from the two drivations, N4 appeared only during cigarette smoking. Latencies of P2～P4 were tended to increase during and after smoking, other latencies tended to decrease during smoking and then increased thereafter. Peak-to-peak amplitudes tended to increase, and then decrease thereafter. In the group mean VEP from 5CH, peak-to-peak amplitudes decreased during and after smoking. Conponent analysis with individual VEPs verified these changes in the group mean VEP significant. These changes in the VEPs were attributed to the early exciting (arousal) effect due to the nicotin attaining to the brain, followed by the inhibiting (sedative) effect due to the short half-life period and tachyphylaxis of nicotin. 2. The correlation coefficients between the number of cigarette smoked in one day and ratio of change of latencies and peak-to-peak amplitudes indicated that the effects of smoking above mentioned appeared more markedly with heavy smokers than with light smokers, indicating more increased susceptibility to nicotin due to cigarette abstinence with the former. 3. Quantitative frequency analysis of EEG indicated arousal effect by the decrease of θ and increase of peak α frequency, and sedative effect by the derease of β1, namely desynchronization. These" arousal sedative effect" corresponded with the VEP changes by cigarette smoking in the present study

Visual evoked potential and electroencephalogram of healthy females during the menstrual cycle

Flash visual evoked potential (VEP) and electroencephalogram (EEG) changes during the menstrual cycle were studied using healthy females having regular menstruation, with 21 at the follicular phase (FP) and 23 at the luteal phase (LP). The following results were obtained. (1)The waveforms of Group Mean VEPs of both groups had approximately similar triphasic contours, consisting of 16 components of P 1-N 8 up to 500 msec of latency. (2)Latencies tended to be longer in LP. (3)Interpeak amplitudes tended to be larger in LP, and one VEP interpeak amplitude (P 5-N 7) of long latency component was significantly larger at LP after eliminating the effect of body height by ANCOVA for 2 CH. (4)Quantitative analysis of EEGs between FP and LP resulted in a tendency for increased α, and decreased β power % at LP. Since estrogen increases the VEP amplitude, and decreases the VEP latency and the α activity of EEGs, the large VEP amplitude, the tendency for prolonged VEP latency, and the tendency for increased α power % at LP observed in this study indicate that the VEP amplitude at LP reflects the effect of estrogen, and that the VEP latency and EEGs at LP reflect the effect of progesterone

Treatment of Symptomatic Non-Parasitic Liver Cysts–Surgical Treatment Versus Alcohol Injection Therapy

Fourteen patients with benign symptomatic non-parasitic cysts of the liver were either surgically treated, had alcohol injected into the cysts, underwent deroofing of the cyst or in 5, a cystectomy was done. Alcohol was injected into 6 patients and there has been no recurrence for as long as 5 years and 8 months after the treatment. Liver dysfunction occurred in 3 patients given blood transfusion during the surgery and/or postoperative course, an elevated temperature (over 39℃) occurred in one patient. Adverse effects of alcohol injections were minor and transient. Based on our experience, the injection of alcohol is an effective treatment for benign symptomatic cyst of the liver. When a malignancy is suspected on imaging and/or cytologic studies, or when alcohol administration is ineffective, then surgery is indicated

Restriction-modification system with methyl-inhibited base excision and abasic-site cleavage activities

The restriction-modification systems use epigenetic modification to distinguish between self and nonself DNA. A modification enzyme transfers a methyl group to a base in a specific DNA sequence while its cognate restriction enzyme introduces breaks in DNA lacking this methyl group. So far, all the restriction enzymes hydrolyze phosphodiester bonds linking the monomer units of DNA. We recently reported that a restriction enzyme (R.PabI) of the PabI superfamily with half-pipe fold has DNA glycosylase activity that excises an adenine base in the recognition sequence (5′-GTAC). We now found a second activity in this enzyme: at the resulting apurinic/apyrimidinic (AP) (abasic) site (5′-GT#C, # = AP), its AP lyase activity generates an atypical strand break. Although the lyase activity is weak and lacks sequence specificity, its covalent DNA–R.PabI reaction intermediates can be trapped by NaBH[subscript 4] reduction. The base excision is not coupled with the strand breakage and yet causes restriction because the restriction enzyme action can impair transformation ability of unmethylated DNA even in the absence of strand breaks in vitro. The base excision of R.PabI is inhibited by methylation of the target adenine base. These findings expand our understanding of genetic and epigenetic processes linking those in prokaryotes and eukaryotes

Somatosensory Evoked Potential (SEP) in schizophrenics

The differences between schizophrenics and healthy subjects in Somatosensory Evoked Potential (SEP) were studied with 174 schizophrenics (98 male and 76 female) and 200 healthy subjects (100 male and 100 female). SEPs evoked by electric stimuli to the right median nerve were recorded through the two derivations (monopolar : C3’→A1+2; bipolar: C3’→Cz), averaging 100 responses, with 1024 msec of analysis time. Individual SEPs were subjected to the component analysis, and the following statistically significant results were obtained. 1. In male schizophrenics, the peak latencies of SEP components were significantly longer in short-latency component, P1 (bipolar), compared with healthy subjects, and shorter in middle-latency component, P2. In female schizophrenics, those were longer in middle-latency components, N2, P3, N3 (monopolar), and N1, P3, N3 (bipolar). 2. The inter-peak amplitudes in schizophrenics of both sexes were significantly larger in middle-latency components without any changes in short-latency components. 3. A few components with significant differences in latencies and inter-peak amplitudes between the subjects taking neuroleptics more than 600 mg, in chlorpromazine equivalent values, or not, as well as between medicated and unmedicated subjects, coincided with those also between the schizophrenics and healthy subjects. Theses differences in SEPs confirmed in the present study, regardless of schizophrenic subtypes, suggest the dysfunction in somatosensory information processing in schizophrenics, and SEP abnormalities may serve as possible elctrophysiological indices for cognitive dysfunction in schizophrenics