Continuing the project described by Kato et al. (2009a, arXiv:0905.1757), we collected times of superhump maxima for SU UMa-type dwarf novae mainly observed during the 2012-2013 season. We found ...three objects (V444 Peg, CSS J203937 and MASTER J212624) having strongly positive period derivatives despite the long orbital period (Porb). By using the period of growing stage (stage A) superhumps, we obtained mass ratios for six objects. We characterized nine new WZ Sge-type dwarf novae. We made a pilot survey of the decline rate of slowly fading part of SU UMa-type and WZ Sge-type outbursts. The decline time scale was found to generally follow the expected Porb^(1/4) dependence and WZ Sge-type outbursts also generally follow this trend. There are some objects which show slower decline rates, and we consider these objects good candidates for period bouncers. We also studied unusual behavior in some objects, including BK Lyn which made a transition from an ER UMa-type state to the novalike (standstill) state in 2013 and unusually frequent occurrence of superoutbursts in NY Ser and CR Boo. We applied least absolute shrinkage and selection operator (Lasso) power spectral analysis, which has been proven to be very effective in analyzing the Kepler data, to ground-based photometry of BK Lyn and detected the dramatic disappearance of the signal of negative superhumps in 2013. We suggested that the mass-transfer rates did not vary strongly between the ER UMa-type state and novalike state in BK Lyn, and this transition was less likely caused by a systematic variation of the mass-transfer rate.
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we studied 86 SU UMa-type dwarf novae. We confirmed the general trends such as the relation between period derivatives and ...orbital periods. There are some systems showing positive period derivatives despite the long orbital periods. We observed the 2011 outburst of the WZ Sge-type dwarf nova BW Scl, and recorded an O-C diagram similar to those of previously known WZ Sge-type dwarf novae. The WZ Sge-type dwarf nova OT J184228.1+483742 showed an unusual pattern of double outbursts composed of an outburst with early superhumps and one with ordinary superhumps. We propose an interpretation that a very small growth rate of the 3:1 resonance due to an extremely low mass-ratio led to a quenching of the superoutburst before the ordinary superhumps appeared. We studied ER UMa-type dwarf novae and found that V1159 Ori showed positive superhumps similar to ER UMa in the 1990s. The recently recognized ER UMa-type object BK Lyn dominantly showed negative superhumps, and its behavior was very similar to the present-day state of ER UMa. The pattern of period variations in AM CVn-type objects were very similar to short-period hydrogen-rich SU UMa-type dwarf novae, making them helium analogue of hydrogen-rich SU UMa-type dwarf novae. SBS 1108+574, a peculiar hydrogen-rich dwarf nova below the period minimum, showed a very similar pattern of period variations to those of short-period SU UMa-type dwarf novae. The mass-ratio derived from the detected orbital period suggests that this secondary is a somewhat evolved star whose hydrogen envelope was mostly stripped during the mass-exchange. CC Scl, MASTER OT J072948.66+593824.4 and OT J173516.9+154708 showed only low-amplitude superhumps with complex profiles. These superhumps are likely a combination of closely separated two periods.
Continuing the project described by Kato et al. (2009, PASJ 61, S395, arXiv:0905.1757), we collected times of superhump maxima for 51 SU UMa-type dwarf novae mainly observed during the 2010-2011 ...season. Although most of the new data for systems with short superhump periods basically confirmed the findings by Kato et al. (2009) and Kato et al. (2010, PASJ 62, 1525, arXiv:1009.5444), the long-period system GX Cas showed an exceptionally large positive period derivative. An analysis of public Kepler data of V344 Lyr and V1504 Cyg yielded less striking stage transitions. In V344 Lyr, there was prominent secondary component growing during the late stage of superoutbursts, and the component persisted at least for two more cycles of successive normal outbursts. We also investigated the superoutbursts of two conspicuous eclipsing objects: HT Cas and the WZ Sge-type object SDSS J080434.20+510349.2. Strong beat phenomena were detected in both objects, and late-stage superhumps in the latter object had an almost constant luminosity during the repeated rebrightenings. The WZ Sge-type object SDSS J133941.11+484727.5 showed a phase reversal around the rapid fading from the superoutburst. The object showed a prominent beat phenomenon even after the end of the superoutburst. A pilot study of superhump amplitudes indicated that the amplitudes of superhumps are strongly correlated with orbital periods, and the dependence on the inclination is weak in systems with inclinations smaller than 80 deg.
As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly ...obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.
Introduction
This study aimed to examine the effect of newly developed scissors-attached micro-forceps in superficial temporal artery-to-middle cerebral artery (STA-MCA) anastomosis for moyamoya ...disease (MMD).
Materials and methods
Of 179 consecutive STA-MCA anastomoses on 95 hemispheres of 71 MMD patients at the University of Fukui Hospital between 2009 and 2023, 49 anastomoses on 26 hemispheres of 21 patients were enrolled in this retrospective cohort clinical trial intraoperative indocyanine green video-angiography did not demonstrate bypass patency in three anastomoses in two patients who were excluded. Twenty-one anastomosis in 19 hemispheres of 16 patients were performed using the conventional micro-forceps (conventional group, CG), and 25 anastomoses in 22 hemispheres of 19 patients were performed using scissors-attached micro-forceps (scissors group, SG). A small infarction near the anastomotic site detected using postoperative diffusion-weighted imaging was defined as anastomotic site infarction (ASI). Factors affecting the occurrence of ASI were examined by univariate, logistic regression, and receiver operating curve (ROC) analysis.
Results
There were no significant differences in clinical parameters such as age, sex, number of sacrificed branches, number of sacrificed large branches, and number of sutures between the CG and SG. However, the clamp time and occurrence of ASI were significantly lower in the SG than in the CG. Logistic regression analysis revealed that the clamp time was the only significant factor predicting the occurrence of ASI. A receiver operating curve analysis also revealed that the clamp time significantly predicted the occurrence of ASI (area under the curve, 0.875; cutoff value, 33.2 min).
Conclusion
The newly developed scissors-attached micro-forceps could significantly reduce the clamp time and occurrence of ASI in STA-MCA anastomosis for MMD.
Abstract
Background
In glioma, decision of infiltrating margin in extensive FLAIR hyperintensity area around enhanced area and only FLAIR hyperintensity without enhanced is difficult. For deciding ...this margin, there are some useful reports using perfusion imaging, diffusion-weighted imaging and PET. Recently, there are some reports that amide proton transfer (APT) imaging is useful for assessment for tumor invasion. In this study, we assessed FLAIR hyperintensity area in gliomas using APT imaging and discussed about pattern of APT signal intensity (SI).
Methods
For patients with glioblastoma (GBM) and oligodendroglioma (OL: IDH-mutant and 1p/19q-codeleted), APT imaging was performed. Gadolinium T1WI, FLAIR and apparent diffusion coefficient (ADC) were performed for tumor invasion and edema. Areas of these sequences were compared with APT hyperintensity and APT and ADC were determined the quantity by SI.
Results
37 sections from 10 GBM and 5 OL patients were assessed. Areas of differences between FLAIR and APT hyperintensity was significantly different between GBM and OL (p = 0.0142). SIs of the hyperintensity area between GBM and OL were different on ADC and APT SIs (ADC: p = 0.0267 / APT: p = 0.055). On GBM, hyperintensity area of APT imaging showed a correlation with hyperintensity area of FLAIR (R2 = 0.600, p < 0.0001). On OL, hyperintensity area of APT imaging showed a strong correlation with hyperintensity area of FLAIR (R2 = 0.806, p < 0.0001), and ADC SI showed correlation with APT SI (R2 = 0.675, p = 0.0019).
Conclusions
FLAIR hyperintensity area of GBM and OL, APT imaging showed different distribution. In FLAIR hyperintensity area of GBM with various phenomenon, APT imaging may indicate increasing area of tumor cell and reactive cells. Furthermore, mismatch between FLAIR and APT hyperintensity area may be useful for differentiation for glioma subtypes.
Several studies have reported that regular endurance exercise attenuated the circulating IL‐6 concentration, but the underlying mechanism remained uncertain. We tested the hypothesis that the ...exercise‐induced alteration of IL‐6 would be associated with the sympathetic nervous system. Subjects were 17 young men trained in endurance exercise and 15 age‐matched sedentary men. Blood sample was obtained from the brachial vein, and serum IL‐6 concentration was measured by ELISA. Plasma adrenaline and noradrenaline concentration were measured as an index of sympathetic nerve activity. IL‐6 was lower in the exercise‐trained, than in the sedentary group (P<0.05). IL‐6 was correlated with adrenaline in the trained group (r=0.63, P<0.05), but such correlation was not observed in the sedentary group. These results suggest that regular endurance exercise attenuates IL‐6, which may be partly associated with sympathetic adrenergic mechanism.
Muscle vasodilator response to mental stress is partly mediated by nitric oxide (NO). Regular endurance exercise augments NO‐mediated endothelium‐dependent vasodilator function. We therefore tested ...the hypothesis that regular endurance exercise augments NO‐mediated endothelium‐dependent vasodilator function, and thereby enhances muscle blood flow response to mental stress. To examine this hypothesis, we measured brachial blood flow response to 3 min of mental arithmetic using Doppler ultrasound in sedentary and endurance trained young men. To assess NO‐mediated endothelium‐dependent vasodilator function, we measured flow‐mediated vasodilatation (FMD) of the brachial artery using ultrasound imaging. Brachial blood flow was increased during mental arithmetic both in the sedentary and the endurance trained group, but the increase in blood flow was less in the trained group. FMD of the brachial artery did not differ between the groups. These results suggest that regular endurance exercise in young men blunts brachial blood flow response to mental arithmetic, which is irrespective of endothelium‐dependent vasodilator function of the brachial artery.
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