Long-term monitoring of the short period SU UMa-type dwarf nova, V844 Herculis

We report on time-resolved CCD photometry of four outbursts of a short-period SU UMa-type dwarf nova, V844 Herculis. We successfully determined the mean superhump periods to be 0.05584(64) days, and 0.055883(3) for the 2002 May superoutburst, and the 2006 April-May superoutburst, respectively. During the 2002 October observations, we confirmed that the outburst is a normal outburst, which is the first recorded normal outburst in V844 Her. We also examined superhump period changes during 2002 May and 2006 April-May superoutbursts, both of which showed increasing superhump period over the course of the plateau stage. In order to examine the long-term behavior of V844 Her, we analyzed archival data over the past ten years since the discovery of this binary. Although photometry is not satisfactory in some superoutbursts, we found that V844 Her showed no precursors and rebrightenings. Based on the long-term light curve, we further confirmed V844 Her has shown almost no normal outbursts despite the fact that the supercycle of the system is estimated to be about 300 days. In order to explain the long-term light curves of V844 Her, evaporation in the accretion disk may play a role in the avoidance of several normal outbursts, which does not contradict with the relatively large X-ray luminosity of V844 Her.Comment: 10 pages, 11 figures, accepted for PAS

Six-month Outcomes after PulseRider- and Conventional Single Stent-assisted Embolization for Bifurcation Aneurysms: A Propensity-adjusted Comparison

Endovascular treatment of wide-necked bifurcation aneurysms (WNBAs) remains challenging despite using a stent. PulseRider is a novel device specifically designed to treat WNBAs, protecting both daughter branches, but the outcomes have not been compared with conventional single stent-assisted embolization. This study aimed to compare the six-month outcomes of PulseRider and single stent-assisted embolization for intracranial unruptured WNBAs using propensity score adjustment. Between February 2012 and October 2021, 46 unruptured WNBAs (34 basilar and 12 middle cerebral arteries) smaller than 10 mm in diameter were treated with PulseRider-assisted embolization (n = 17) or single stent-assisted embolization (n = 29). The immediate and six-month outcomes were compared using inverse probability of treatment weighting analysis. The immediate adequate occlusion rates for the PulseRider- and single stent-assisted embolization were similar (47.1% vs. 62.1%). At six months, adequate occlusion rates for the two groups were also similar (94.1% vs. 86.2%). However, the complete obliteration rate was significantly high after PulseRider-assisted embolization (88.2% vs. 41.4%, adjusted OR 10.54, 95% CI 1.93-57.63). The angiographical improvement rate was also significantly high after PulseRider-assisted embolization (70.6% vs. 37.9%, adjusted OR 6.06, 95% CI 1.54-23.76). The neurologic thromboembolic complication rate was 0% after PulseRider-assisted embolization and 3.4% after single stent-assisted embolization. PulseRider-assisted embolization of WNBAs smaller than 10 mm in diameter was associated with complete obliteration and angiographical improvement at six months. The unique shape of the PulseRider might contribute to the improved midterm aneurysm occlusion

Pathological changes of brain oscillations following ischemic stroke

Brain oscillations recorded in the extracellular space are among the most important aspects of neurophysiology data reflecting the activity and function of neurons in a population or a network. The signal strength and patterns of brain oscillations can be powerful biomarkers used for disease detection and prediction of the recovery of function. Electrophysiological signals can also serve as an index for many cutting-edge technologies aiming to interface between the nervous system and neuroprosthetic devices and to monitor the efficacy of boosting neural activity. In this review, we provided an overview of the basic knowledge regarding local field potential, electro- or magneto- encephalography signals, and their biological relevance, followed by a summary of the findings reported in various clinical and experimental stroke studies. We reviewed evidence of stroke-induced changes in hippocampal oscillations and disruption of communication between brain networks as potential mechanisms underlying post-stroke cognitive dysfunction. We also discussed the promise of brain stimulation in promoting post stroke functional recovery via restoring neural activity and enhancing brain plasticity

The effect of type 2 diabetes on CD36 expression and the uptake of oxLDL Diabetes affects CD36 and oxLDL uptake

We investigated whether type 2 diabetes mellitus (T2DM), a risk factor of stroke, affects the level of scavenger receptor CD36 and the uptake of its ligand, oxidized LDL (oxLDL); and whether pioglitazone, a drug that enhances CD36, promotes oxLDL uptake. Compared to normoglycemic db/+ mice, adult db/db mice showed a pronounced reduction in surface CD36 expression on myeloid cells from the blood, brain, and bone marrow as detected by flow cytometry, which correlated with elevated plasma soluble-CD36 as determined by ELISA. Increased CD36 expression was found in brain macrophages and microglia of both genotypes 7 days after ischemic stroke. In juvenile db/db mice, prior to obesity and hyperglycemia, only a mild reduction of surface CD36 was found in blood neutrophils, while all other myeloid cells showed no difference relative to the db/+ strain. In vivo, oral pioglitazone treatment for four weeks increased CD36 levels on myeloid cells in db/db mice. In vitro, uptake of oxLDL by bone marrow derived macrophages (BMDMs) of db/db mice was reduced relative to db/+ mice in normal glucose medium. OxLDL uptake inversely correlated with glucose levels in the medium in db/+ BMDMs. Furthermore, pioglitazone restored oxLDL uptake by BMDMs from db/db mice cultured in high glucose. Our data suggest that T2DM is associated with reduced CD36 on adult myeloid cells, and pioglitazone enhances CD36 expression in db/db cells. T2DM or high glucose reduces oxLDL uptake while pioglitazone enhances oxLDL uptake. Our findings provide new insight into the mechanism by which pioglitazone may be beneficial in the treatment of insulin resistance