Magnetically modulated microwave absorption (MMMA) at low magnetic fields in (BEDT-TTF)-superconductors

We report magnetically modulated microwave absorption (MMMA) at low magnetic fields in crystals of the organic superconductors αt-(BEDT-TTF)2I3 and κ-(BEDT-TTF)2Cu(NCS)2. In both cases a strong MMMA-signal can easily be found below the critical temperature Tc. In some selected crystals series of narrow, periodically spaced lines are observed comparable to corresponding spectra of the CuO-type high Tcsuperconductors. A model developed for the HTSC's single crystals is used to interpret the results of the organic superconductors

A stable superconducting state at 8K and ambient pressure in αt-(BEDT-TTF)2I3

We report bulk superconductivity at 8 K and ambient pressure in crystals of α t (BEDT-TTF)2I3. In contrast to the earlier observed metastable superconducting state at 8 K in crystals of β-(BEDT-TTF)2I3 here the superconducting state is stable and the crystals can be prepared by tempering α-(BEDT-TTF)2I3 above 70 °C for several days. ac-susceptibility measurements show that the observed superconducting state at 8 K is a bulk property of the crystals. Resistivity measurements indicate a sharp superconducting transition at 8 K with an onset temperature of about 9 K. The upper critical fields Hc2 at 1.3 K lie between 3 and 11 T depending on the direction of the magnetic field with respect to the crystal axes. ESR- as well as NMR-measurements indicate a total transformation of the α-phase crystals into the new superconducting α t -crystals after tempering

The endogenous neuropeptide calcitonin gene-related peptide after spontaneous subarachnoid hemorrhage–A potential psychoactive prognostic serum biomarker of pain-associated neuropsychological symptoms

Background: The pronociceptive neuromediator calcitonin gene-related peptide (CGRP) is associated with pain transmission and modulation. After spontaneous subarachnoid hemorrhage (sSAH), the vasodilatory CGRP is excessively released into cerebrospinal fluid (CSF) and serum and modulates psycho-behavioral function. In CSF, the hypersecretion of CGRP subacutely after good-grade sSAH was significantly correlated with an impaired health-related quality of life (hrQoL). Now, we prospectively analyzed the treatment-specific differences in the secretion of endogenous CGRP into serum after good-grade sSAH and its impact on hrQoL. Methods: Twenty-six consecutive patients (f:m = 13:8; mean age 50.6 years) with good-grade sSAH were enrolled (drop out n = 5): n = 9 underwent endovascular aneurysm occlusion, n = 6 microsurgery, and n = 6 patients with perimesencephalic SAH received standardized intensive medical care. Plasma was drawn daily from day 1 to 10, at 3 weeks, and at the 6-month follow-up (FU). CGRP levels were determined with competitive enzyme immunoassay in duplicate serum samples. All patients underwent neuropsychological self-report assessment after the onset of sSAH (t1: day 11–35) and at the FU (t2). Results: During the first 10 days, the mean CGRP levels in serum (0.470 ± 0.10 ng/ml) were significantly lower than the previously analyzed mean CGRP values in CSF (0.662 ± 0.173; p = 0.0001). The mean serum CGRP levels within the first 10 days did not differ significantly from the values at 3 weeks (p = 0.304). At 6 months, the mean serum CGRP value (0.429 ± 0.121 ng/ml) was significantly lower compared to 3 weeks (p = 0.010) and compared to the first 10 days (p = 0.026). Higher mean serum CGRP levels at 3 weeks (p = 0.001) and at 6 months (p = 0.005) correlated with a significantly poorer performance in the item pain, and, at 3 weeks, with a higher symptom burden regarding somatoform syndrome (p = 0.001) at t2. Conclusion: Our study reveals the first insight into the serum levels of endogenous CGRP in good-grade sSAH patients with regard to hrQoL. In serum, upregulated CGRP levels at 3 weeks and 6 months seem to be associated with a poorer mid-term hrQoL in terms of pain. In migraineurs, CGRP receptor antagonists have proven clinical efficacy. Our findings corroborate the potential capacity of CGRP in pain processing

Both coiling and clipping induce the time-dependent release of endogenous neuropeptide Y into serum

BackgroundThe vaso- and psychoactive endogenous Neuropeptide Y (NPY) has repeatedly been shown to be excessively released after subarachnoid hemorrhage and in numerous psychiatric disorders. NPY is stored in sympathetic perivascular nerve fibers around the major cerebral arteries. This prospective study was designed to analyze the impact of microsurgical and endovascular manipulation of the cerebral vasculature versus cranio- and durotomy alone on the serum levels of NPY.Methods58 patients (drop-out n = 3; m:f = 26:29; mean age 52.0 ± 14.1 years) were prospectively enrolled. The vascular group underwent repair for unruptured intracranial aneurysms (UIA) of the anterior circulation [endovascular aneurysm occlusion (EV) n = 13; microsurgical clipping (MS) n = 17]; in the non-vascular group, 14 patients received microsurgical resection of a small-sized convexity meningioma (CM), and 11 patients with surgically treated degenerative lumbar spine disease (LD) served as control. Plasma was drawn (1) before treatment (t0), (2) periprocedurally (t1), (3) 6 h postprocedurally (t2), (4) 72 h postprocedurally (t3), and (5) at the 6-week follow-up (FU; t4) to determine the NPY levels via competitive enzyme immunoassay in duplicate serum samples. We statistically evaluated differences between groups by calculating one-way ANOVA and for changes along the time points using repeated measure ANOVA.ResultsExcept for time point t0, the serum concentrations of NPY ranged significantly higher in the vascular than in the non-vascular group (p < 0.001), with a slight decrease in both vascular subgroups 6 h postprocedurally, followed by a gradual increase above baseline levels until FU. At t3, the EV subgroup showed significantly higher NPY levels (mean ± standard deviation) than the MS subgroup (0.569 ± 0.198 ng/mL vs. 0.415 ± 0.192 ng/mL, p = 0.0217). The highest NPY concentrations were measured in the EV subgroup at t1, t3, and t4, reaching a climax at FU (0.551 ± 0.304 ng/mL).ConclusionOur study reveals a first insight into the short-term dynamics of the serum levels of endogenous NPY in neurosurgical and endovascular procedures, respectively: Direct manipulation within but also next to the major cerebral arteries induces an excessive release of NPY into the serum. Our findings raise the interesting question of the potential capacity of NPY in modulating the psycho-behavioral outcome of neurovascular patients

New high-DQE Imaging Plate scanner using the reflected readout laser signal for noise corrections

Imaging Plates (IPs) are in principle ideal electron detectors combining a large active layer area with a high sensitivity, linear dynamic range detection over 5 orders of magnitude. A moderate resolution and a decreasing detection quantum efficiency (DQE) for higher electron doses limit their use so far. The decrease of the DQE results from linear noise contributed by readout laser instabilities and inhomogeneities of the IP active layer. Here we present data on a new IP drum scanner prototype. This scanner combines twin channel amplification electronics with a new type of readout laser which allows a smaller readout focus and increased stability. The current nominal pixel size is 25 m, and the measured modulation transfer function (MTF) indicates that further reduction of the scanning step size down to pixel sizes in the range of 12-15 m should be possible. A unique feature of the new scanner is the simultaneous recording of the reflected readout laser light. The reflected light signal can be used for a posteriori alignment of repeated scans of one individual IP and for a correction of one part of the high spatial frequency noise contribution (reflected light correction). The posteriori alignment now allows an easy conventional gain normalization of the luminescence signal without using special markers on the IP. Both corrections lead to an increase of the DQE for high electron doses

Imaging Plate noise reduction using the simultaneous recording of the reflected readout laser signal

Spatial resolution and detection noise characteristics are the most important properties of an electron detection system. For Imaging Plates (IP) the granularity of the beam sensitive layer and its surface topology affect the recorded luminescence signal. It results in a characteristic and reproducible fluctuation of the luminescence signal for each individual JP and adds non-linear noise to the detected signal. Here we present first results on resolution and noise correction of a new IP scanner based on a previous design [1] which now allows the detection of luminescence and reflected light signal simultaneously

III. Ventricle diameter increase during ventricular drainage challenge – A predictor of shunt dependency after subarachnoid hemorrhage

Hydrocephalus with the need for shunt placement is a common sequela after aneurysmal subarachnoid hemorrhage (aSAH). In 2009 Chan et al. published a formula to predict shunt dependency in SAH patients, the failure risk index (FRI). We reevaluated the FRI within the aSAH population in our hospital and wanted to identify easier measurements forecast shunt dependency. We retrospectively analyzed data from patients with aSAH treated in our neuro-intensive care unit and calculated the FRI according to the paper by Chan et al. 2013 and data were compared to the results of Chan et al. 38 patients were included in this study, 24 female and 14 male. 38% suffered a SAH WFNS 1, 19% WFNS II, 24% WFNS III, 5% WFNS IV and 14% WFNS V. 17 patients underwent a shunt implantation (group 1), 21 patients did not (group 2). The calculated FRI Index did not correlate with the expectancy of shunt implantation in 22% of the cases (group 1). In group 2 the FRI index and the prediction of shunt dependency did not match in 33% of the cases. Furthermore, we found the increase of the third ventricle diameter to be predictive in 67% for failed EVD challenge and the decrease of the third ventricle diameter predictive in 67% for successful EVD challenge. In this study, we were not able to confirm the results of the FRI designed by Chan et al within our patient population. Furthermore, we consider the increase of the third ventricle diameter to be a simpler and more reliable predictor of shunt dependency. (C) 2019 Elsevier Ltd. All rights reserved

Restoration of Functional Integrity After Evacuation of Chronic Subdural Hematoma—An Age-Adjusted Analysis of 697 Patients

OBJECTIVE: Although chronic subdural hematoma (CSH) can be treated by surgery, little is known about age-dependent symptoms and age-adjusted rates of restoring functional integrity. To evaluate the clinical symptoms and the course of CSH in patients of different age groups (AGs), we reviewed patients with CSH treated at our department over the past 22 years. METHODS: This retrospective analysis included 697 patients with CSH (461 men, 236 women; mean age 70.1 years). Subgroup analysis was done according to AG 1) 95 years. RESULTS: Most patients had been treated with burr-hole trephination and implantation of a subdural drain (96.5%; n = 673). No significant difference concerning surgical morbidity and mortality was found between the AGs, but patients >75 years more frequently required reoperation (P = 0.001). Preoperatively, the most common symptoms were headache in AGs 1 and 2 (56.3% and 48.5%) and mnestic deficits in AGs 3-5 (54.9%, 51.9%, and 50.0%). After surgery, the clinical symptoms of CSH had significantly abated in all age groups. The most common clinical residuals were motor deficits in AG 1 (10.4%), mnestic deficits in AG 2 (10.7%), AG 4 (24.1%), and AG 5 (50.0%), and organic brain syndrome in AG 3 (15.0%). CONCLUSION: CSH predominantly caused unspecific symptoms such as headache and cognitive decline. CSH surgery immediately relieved symptoms in patients of all AGs. However, improvement rates significantly depended on patient age. This should be taken into consideration when advising on surgical treatment of CSH