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The selective vulnerability of specific neuronal subpopulations to trimethyltin (TMT), an organotin compound with neurotoxicant effects selectively involving the limbic system and especially marked in the hippocampus, makes it useful to obtain in vivo models of neurodegeneration associated with behavioural alterations, such as hyperactivity and aggression, cognitive impairment as well as temporal lobe epilepsy. TMT has been widely used to study neuronal and glial factors involved in selective neuronal death, as well as the molecular mechanisms leading to hippocampal neurodegeneration (including neuroinflammation, excitotoxicity, intracellular calcium overload, mitochondrial dysfunction and oxidative stress). It also offers a valuable instrument to study the cell-cell interactions and signalling pathways that modulate injury-induced neurogenesis, including the involvement of newly generated neurons in the possible repair processes. Since TMT appears to be a useful tool to damage the brain and study the various responses to damage, this review summarises current data from in vivo and in vitro studies on neuroprotective strategies to counteract TMT-induced neuronal death, that may be useful to elucidate the role of putative candidates for translational medical research on neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

ABSTRACT We present a detailed analysis of the X-ray spectrum of the Seyfert 2 galaxy NGC 454E, belonging to the interacting system NGC 454. Observations performed with Suzaku, XMM-Newton and Swift allowed us to detect a dramatic change in the curvature of the 2-10 keV spectrum, revealing a significant variation of the absorbing column density along the line of sight (from ∼ 1 × 1024 cm −2 to ∼ 1 × 1023 cm −2). Consequently, we propose this source as a new member of the class of 'changing look' active galactic nuclei (AGN), i.e. AGN that have been observed both in Compton thin ( NH= 1023 cm−2) and reflection-dominated states (Compton thick, NH > 1024 cm−2). Due to the quite long time lag (six months) between the Suzaku and XMM-Newton observations, we cannot infer the possible location of the obscuring material causing the observed variability. In the 6-7 keV range, the XMM-Newton observation also shows a clear signature of the presence of an ionized absorber. Since this feature is not detected during the Suzaku observation (despite its detectability), the simplest interpretation is that the ionized absorber is also variable; its location is estimated to be within ∼ 10−3 pc from the central black hole, probably much closer in than the rather neutral absorber. [ABSTRACT FROM AUTHOR]

Context. Active galactic nuclei (AGN) emit radiation over a wide range of wavelengths, with a peak of emission in the far-UV region of the electromagnetic spectrum, a spectral region that is historically difficult to observe. Aims. Using optical, GALEX UV, and XMM-Newton data we derive the spectral energy distribution (SED) from the optical/UV to X-ray regime of a sizeable sample of AGN. The principal motivation is to investigate the relationship between the optical/UV emission and the X-ray emission and provide bolometric corrections to the hard X-ray (2-10 keV) energy range, kbol, the latter being a fundamental parameter in current physical cosmology. Methods. We construct and study the X-ray to optical SED of a sample of 195 X-ray selected Type 1 AGN belonging to the XMM-Newton bright serendipitous survey (XBS). The optical-UV luminosity was computed using data from the Sloan Digital Sky Survey (SDSS), from our own dedicated optical spectroscopy and the satellite GALaxy evolution EXplorer (GALEX), while the X-ray luminosity was computed using XMM-Newton data. Because it covers a wide range of redshift (0.03 < z ≲2.2), X-ray luminosities (41.8 < log L[2-10] keV < 45.5 erg/s) and because it is composed of "bright objects", this sample is ideal for this kind of investigation. Results. We confirm a highly significant correlation between the accretion disc luminosity Ldisc and the hard X-ray luminosity L[2-10] keV, in the form Ldisc ∝ LΔ [2-10] keV, where Δ = 1.18 ± 0.05. We find a very shallow dependence of kbol on the X-ray luminosity with respect to the broad distribution of values of kbol. We find a correlation between kbol and the hard X-ray photon index Γ2-10 keV and a tight correlation between the optical-to-X-ray spectral index αox and kbol, so we conclude that both Γ2-10 keV and αox can be used as a proxy for kbol. [ABSTRACT FROM AUTHOR]

Trimethyltin (TMT), an organotin compound considered a useful tool to obtain an experimental model of neurodegeneration, exhibits neurotoxicant effects selectively localised in the limbic system and especially in the hippocampus, which are different in the rat and in mice. In the rat hippocampus, we investigated the expression of aldehyde 4-hydroxynonenal, a major bioactive marker of membrane lipid peroxidation, heat shock protein (HSP) 110/105 family members, markers of oxidative stress, and the neuroinflammatory marker cyclooxygenase-2 after TMT-intoxication at various time points after treatment. Our data show that TMT-induced neurodegeneration in the rat hippocampus is associated specifically with oxidative stress and lipid peroxidation, but not with HSP expression, indicating species-specific differences in the neurotoxicity of TMT between rats and mice. [ABSTRACT FROM AUTHOR]

We observed a 32-year-old female who had suffered from a left hemisphere ischemic stroke with right hemiparesis at the age of seven. At that time, a CT scan demonstrated a left ischemic lesion in nucleo-capsular region and a cerebral angiogram documented a complete occlusion of the supraclinoid segment of the internal carotid artery. When we observed the patient neurological examination demonstrated a moderate right brachio-crural hemiparesis. A brain MRI showed an old ischemic lesion involving the left nucleo-capsular and ‘flow voids’ suggestive for a vascular malformation in the left sylvian region. A cerebral rotational angiogram with 3-D reconstructions demonstrated a dolichoectatic left middle cerebral artery with an unusual ‘corkscrew’ aspect. Middle cerebral artery dolichoectasia is a rare pathological condition that may manifest with a stroke. The patients with intracranial arterial dolichoectasia (IADE) are most often hypertensive elderly men, and, to the best of our knowledge, an ischemic stroke associated with IADE has never been reported in children. [ABSTRACT FROM AUTHOR]

The article focuses on the case report of a 29 year-old woman suffering with a rhinoliquorrea followed by pneumococcal meningitis. Her first sign was a sensation of watery discharge into the nasopharynx lasting for almost two years. A CT scan of the petrous bone documented the aplasia of the cochlea with a common cavity. The patient underwent a subtotal petrosectomy. After six months no evidence of liquorrhea was noticed. The dysplasia of the inner ear may be associated with a communication to the subarachnoid spaces with the middle ear through a dehiscence in the stapes footplate when a tapering of the internal auditory meatus is present resulting in cerebrospinal fluid fistula.

Hydromorphological stream assessment has significantly expanded over the last years, but a need has emerged from recent reviews for more comprehensive, process-based methods that consider the character and dynamics of the river with greater accuracy. With this as a focus, a series of hydromorphological tools have been developed and/or further extended in Europe within the context of the REFORM (REstoring rivers FOR effective catchment Management) project. The aim of this paper is to present the set of REFORM hydromorphological assessment methods and, based on some examples of their application, to illustrate and discuss their synergic use, specific features, limitations and strengths. This assessment and monitoring includes three tools: the Morphological Quality Index (MQI), the Morphological Quality Index for monitoring (MQIm), and the Geomorphic Units survey and classification System (GUS). These tools constitute the assessment phase of an overall multi-scale, process-based hydromorphological framework developed in REFORM. The MQI is aimed at an assessment, classification and monitoring of the current morphological state; the MQIm aims at monitoring the tendency of morphological conditions (enhancement or deterioration); the GUS provides a characterization, classification and monitoring of geomorphic units. A series of examples are used to illustrate the potential range of application, including: (i) an assessment of morphological conditions; (ii) an assessment of the morphological effects of restoration projects; (iii) an evaluation of the geomorphic impacts of interventions for risk mitigation; and (iv) an integrated use of MQI and GUS to assess and characterise morphological conditions. Finally, some of the main features, strengths and peculiarities of the three hydromorphological tools are discussed with the support of examples of their application. [ABSTRACT FROM AUTHOR]

Objectives: Dural arteriovenous fistulas (DAVFs) are a challenging condition in vascular neurosurgery. Disease natural history and its management is still debated. In the present paper we report our center series on DAVFs over a period of 10 years. Our data were compared with relevant literature. Patient and methods: Our series includes 45 cases: 14 cavernous sinus, 11 transverse-sigmoid, 8 patients tentorial, 6 anterior cranial fossa, 5 patients spinal, 1 patient foramen magnum. Results and conclusions: DVAFs distribution, clinical presentation and hemorrhagic risk are discussed. Cavernous sinus DAVFs are the most common site in our series. Other locations in order of frequency are transverse-sigmoid sinus, tentorial, anterior cranial fossa, spinal and foramen magnum. The majority of patients presented with non-aggressive symptoms. 18% presented with intracranial hemorrhage: all the hemorrhages occurred in high-grade DAVFs. For most patients, endovascular treatment, transarterial or transvenous, was the first option. Surgery was performed for the anterior cranial fossa DAVFs and other complex lesions draining mostly transverse-sigmoid sinus and tentorium. In 7% of cases a combination of endovascular + surgical treatment was used. Our series has been carefully analyzed in comparison 'side by side' with most relevant literature on DVAFs, focusing particularly on management strategies, therapeutic options and risks related to treatment. [ABSTRACT FROM AUTHOR]

Objective: Cerebral vasospasm (VS) is one of the factors that can most significantly worsen the prognosis after aneurysmal subarachnoid hemorrhage (SAH). A substantial body of evidence supports the idea that CSF diversion could prevent VS, even if this issue is still much debated. External ventricular drainage (EVD) is the recommended procedure for post-hemorrhagic hydrocephalus. In this study we analyzed whether EVD, placed for acute hydrocephalus, is effective in reducing the incidence of clinical and radiological cerebral vasospasm in patients who underwent endovascular treatment for aneurysmal SAH. Patients and methods: We retrospectively studied the incidence of radiologically confirmed VS in 141 patients treated endovascularly for aneurysmal SAH: 80 underwent EVD for hydrocephalus, 61 did not undergo EVD. Results: VS occurred in 8.75% of cases (7 patients) in the first groups, while in 22.95% (14 patients) in the second group. In addition, patients not treated with EVD display a prevalence of VS in lower Fisher grades compared to the other group. Conclusion: Our data indicate that CSF drainage reduces the risk of vasospasms in patients with endovascular treatment for aneurysmal SAH. [ABSTRACT FROM AUTHOR]

Objective: Indocyanine green video angiography (ICG-VA) is a non invasive, easy to use and a very useful tool for various neurosurgical procedures. Initially introduced in vascular neurosurgery since 2003, it's applications have broadened over time, both in vascular applications and in other neurosurgical fields. The objective of our study is to review all published literature about ICG-VA, cataloguing its different applications. Methods: A systematic review of all pertinent literature articles published from January 2003 to May 2014 using Pubmed access was performed using pertinent keywords; cross check of references of selected articles was performed in order to complete bibliographical research. Results of research were grouped by pathology. Results and conclusions: The paper systematically analyses ICG-VA different applications in neurosurgery, from vascular neurosurgery to tumor resection and endoscopic applications, focusing on reported advantages and disadvantages, and discussing future perspectives. [ABSTRACT FROM AUTHOR]

Background: Spontaneous, non traumatic subarachnoid hemorrhage (SAH) is a significant clinical problem that occurs most commonly as a result of aneurysm rupture. In approximately 15 % of cases, nor aneurysm or other vascular malformation can be identified by cerebral angiography as origin of the hemorrhage, and these are commonly defined as idiopathic SAH (ISAH). Because of the negative angiography, limited extension of the bleeding with prevalent prepontine pattern and the benign prognosis, the venous causes has been preferred rather than the arterial ones. In the literature recent studies have suggested a possible contribution by primitive variants of Basal vein of Rosenthal (BVR) in its the pathogenesis of ISAH, commonly grouped according Watanabe classification (type A, B and C). In this paper we evaluated the prevalence of anatomical variants of BVR in ISAH. Methods: Venous drainage at angiography was retrospectively analyzed in 40 patients with ISAH and in 40 with unruptured aneurysms as controls. Results and conclusions: Previous studies displayed a significant prevalence of BVR type C variants in ISAH. Conversely in our study we recognized variant B as prevalent, in which the BVR bifurcates to drain anteriorly into the uncal vein and posteriorly into the Galenic system. Similarly to variant C (in which the BVR drains via perimesencephalic 'bridging' veins into cavernous, sphenoparietal, petrosal sinus or directly into transverse sinus) also variant B might be subjected to those stress mechanisms and intrinsic system 'fragility' and for reasons yet to determine, sets off a consequent hemorrhage with clinical and radiological features typical of ISAH. [ABSTRACT FROM AUTHOR]

Background and purpose Epileptic seizures account for 24-40% of all clinical onsets in patients with brain arteriovenous malformations ( AVMs). Methods We retrospectively reviewed the angioarchitectural features of AVMs associated with seizures in 168 patients admitted to our Department from 1997 to 2012. Patients were dichotomized according to demographic characteristics, type of treatment, bleeding occurrence, and morphological and topographic features. Clinical status at admission and discharge was also recorded. The association of each one of these variables with seizures occurrence was statistically tested. Continuous variables and outcome were compared with Student's t-test, whereas categorical ones were compared using Fisher's exact test. The independent contribution of some seizures predictors was assessed with a logistic regression model. Associations were considered significant for P < 0.05. Results About 29% patients showed seizures and 47% bleeding. No significant difference in age and sex was observed between patients with and without seizures. AVMs > 4 cm ( P = 0.001) and those fed by dilated arterial feeders ( P = 0.02) were associated with increased risk of seizures. A higher risk of seizures occurrence was also observed in cortical AVMs compared with deeper ones (75.5% vs. 55.4%; P = 0.01), and in AVMs fed by middle and posterior cerebral arteries branches compared with the other vessels (81.6% vs. 45.3%; P < 0.001 and 48.9% vs. 23.5%; P = 0.002, respectively). No lobar predisposition was observed. A nidus > 4 cm also appeared as an independent risk factor of seizures occurrence ( OR 2.82; 95% CI, 1.26-6.31; P = 0.009) at logistic regression analysis. Conclusions AVM morphology, especially nidus dimension, appeared to more significantly influence seizures occurrence than their topography. [ABSTRACT FROM AUTHOR]

Aims. We derive masses of the central supermassive black hole (SMBH) and accretion rates for 154 type 1 AGN belonging to a well-defined X-ray-selected sample, the XMM-Newton serendipitous sample (XBS). Methods. We used the most recent "single-epoch" relations, based on Hβ and MgIIλ2798 Å emission lines, to derive the SMBH masses.We then used the bolometric luminosities, computed on the basis of an SED-fitting procedure, to calculate the accretion rates, both absolute and normalized to the Eddington luminosity (Eddington ratio). Results. The selected AGNs cover a range of masses from 107 to 1010 M⊕ with a peak around 8 × 108 M⊕ and a range of accretion rates from 0.01 to ∼50 M⊕/year (assuming an efficiency of 0.1), with a peak at ∼1 M⊕/year. The values of Eddington ratio range from 0.001 to ∼0.5 and peak at 0.1. [ABSTRACT FROM AUTHOR]

Abstract: It is common practice nowadays to derive spins and 3D shapes of asteroids from the inversion of photometric light curves. However, this method requires, in general, a good number of photometric points and dedicated observing sessions. On the other hand, the photometric observations carried out by the Gaia mission will be sparse and their number relatively small. For this reason, a multi-parametric shape described by a large number of elementary facets cannot probably be derived from Gaia data alone. Therefore, the Data Processing and Analysis Consortium (DPAC), implemented a simpler solution as an unattended data reduction pipeline, which relies on three axial ellipsoids for the shape representation. However, overall accuracy of such triaxial shape solutions has to be assessed. How adequate is an ellipsoidal approximation to represent the overall properties of an irregular body? Which error is made on the volume in comparison to a more accurate model with irregular shape? To answer these questions, we have implemented numerical procedures for comparing ellipsoids to more complex and irregular shapes, and we performed a full simulation of the photometric signal from these objects, using both shape representations. Implementing the same software algorithm that will be used for the analysis of Gaia asteroid photometry, rotation period, spin axis orientation and ellipsoidal shape were derived from simulated observations of selected Main Belt asteroids assuming a geometric scattering model (work is in progress for more complex scattering models). Finally, these simulated Gaia results were compared to check the relevance of the ellipsoidal solution in comparison to multi-parametric shapes. We found that the ellipsoids by photometry inversion are closely similar to the best-fitting ellipsoids of the simulated complex shapes and that the error on the asteroid volume (relative to a complex shape) is generally low, usually around 10%. [Copyright &y& Elsevier]

Fluoropolymers are continuously increasing their application fields in many industrial areas because of their unique properties, such as heat and chemical resistance, high purity, lubricity, dielectric properties etc. [Encyclopedia of Chemical Technology, vol. 11, 3rd ed., Wiley, New York, 1980, p. 1]. This paper describes very promising results obtained thanks to the Ausimont proprietary technology of microemulsion polymerization in formulating bimodal and multimodal fluoropolymer dispersions with superior film forming behavior. Very carefully size-controlled nanoparticles, ranging from 10 to 60 nm, allow to obtain blend with 200–250 nm particles that not only do have highly improved film formation properties, but also show outstanding film characteristics with respect to conventional 200/110 nm bimodal PTFE latexes. Moreover, the high flexibility in selecting polymer characteristics such as molecular weight, particle shape, monomer composition and melting properties allows to have sintered films with a denser and tougher structure characterized by superior mechanical and barrier properties. [Copyright &y& Elsevier]

Presents a study which examined the global gene expression pattern in inflamed colonic tissue before and following recombinant human interleukin-11 treatment using oligonucleotide microarrays. Materials and methods; Results; Discussion.