228 research outputs found
The reversal of the SF-density relation in a massive, X-ray selected galaxy cluster at z=1.58: results from Herschel
Dusty, star-forming galaxies have a critical role in the formation and
evolution of massive galaxies in the Universe. Using deep far-infrared imaging
in the range 100-500um obtained with the Herschel telescope, we investigate the
dust-obscured star formation in the galaxy cluster XDCP J0044.0-2033 at z=1.58,
the most massive cluster at z >1.5, with a measured mass M200= 4.7x10
Msun. We perform an analysis of the spectral energy distributions (SEDs) of 12
cluster members (5 spectroscopically confirmed) detected with >3
significance in the PACS maps, all ULIRGs. The individual star formation rates
(SFRs) lie in the range 155-824 Ms/yr, with dust temperatures of 2435 K.
We measure a strikingly high amount of star formation (SF) in the cluster core,
SFR ( 1875158 Ms/yr, 4x higher than the amount of star
formation in the cluster outskirts. This scenario is unprecedented in a galaxy
cluster, showing for the first time a reversal of the SF-density relation at
z~1.6 in a massive cluster.Comment: Letter accepted for publication in MNRAS, ESA Press Release on 18
December 201
Total endovascular treatment for extent type 1 and 5 thoracoabdominal aortic aneurysms
OBJECTIVE: The study objective was to describe the results of thoracic endovascular aortic repair with the intentional coverage of the celiac artery and distal supramesenteric landing zone for extent type 1 and type 5 thoracoabdominal aortic aneurysms. METHODS: Inclusion criteria were thoracic endovascular aortic repair with celiac artery coverage to treat elective or urgent extent type 1 and 5 thoracoabdominal aortic aneurysms. Primary end points were in-hospital and follow-up survival, freedom from aortic-related mortality, and freedom from reintervention. RESULTS: Thoracoabdominal disease extent was type 1 in 12 patients (71%) and type 5 in 5 patients (29%). Urgent repair was performed in 4 patients (23.5%). Primary technical success was 100%. Early mortality and visceral ischemia did not occur. Permanent spinal cord ischemia rate was 6% (n = 1). Follow-up ranged from 3 to 120 months (interquartile range, 12-36.5). Survival estimate was 85% \ub1 9% (95% confidence interval, 67-94) at 1 year and 49% \ub1 17% (95% confidence interval, 21-78) at 5 years. Cumulative freedom from aortic-related mortality was 94%, and estimated freedom from reintervention at 1 and 5 years was 93% \ub1 7% (95% confidence interval, 68-99). Neither type 1 endoleaks nor distal stent-graft migration causing superior mesenteric artery occlusion was detected. CONCLUSIONS: Thoracic endovascular aortic repair with intentional coverage of celiac artery for extent 1 and 5 thoracoabdominal aortic aneurysms had satisfactory results in selected patients at high risk for open repair. Visceral ischemia did not occur, but spinal cord ischemia is still high at 6%. At midterm follow-up, neither endoleak development nor aortic reintervention was related to the inadequate distal landing zone. Follow-up survival is satisfactory and comparable to open repair
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Cortical spreading depression as a target for anti-migraine agents
Spreading depression (SD) is a slowly propagating wave of neuronal and glial depolarization lasting a few minutes, that can develop within the cerebral cortex or other brain areas after electrical, mechanical or chemical depolarizing stimulations. Cortical SD (CSD) is considered the neurophysiological correlate of migraine aura. It is characterized by massive increases in both extracellular K+ and glutamate, as well as rises in intracellular Na+ and Ca2+. These ionic shifts produce slow direct current (DC) potential shifts that can be recorded extracellularly. Moreover, CSD is associated with changes in cortical parenchymal blood flow. CSD has been shown to be a common therapeutic target for currently prescribed migraine prophylactic drugs. Yet, no effects have been observed for the antiepileptic drugs carbamazepine and oxcarbazepine, consistent with their lack of efficacy on migraine. Some molecules of interest for migraine have been tested for their effect on CSD. Specifically, blocking CSD may play an enabling role for novel benzopyran derivative tonabersat in preventing migraine with aura. Additionally, calcitonin gene-related peptide (CGRP) antagonists have been recently reported to inhibit CSD, suggesting the contribution of CGRP receptor activation to the initiation and maintenance of CSD not only at the classic vascular sites, but also at a central neuronal level. Understanding what may be lying behind this contribution, would add further insights into the mechanisms of actions for âgepantsâ, which may be pivotal for the effectiveness of these drugs as anti-migraine agents. CSD models are useful tools for testing current and novel prophylactic drugs, providing knowledge on mechanisms of action relevant for migraine
Progress in cardiovascular anastomoses: will the vascular join replace Carrel's technique?
Background: Vascular reconstructions are becoming challenging due to the comorbidity of the aging population and since the introduction of minimally invasive approaches. Many sutureless anastomosis devices have been designed to facilitate the cardiovascular surgeon's work and the vascular join (VJ) is one of these. We designed an animal study to assess its reliability and long-term efficacy. Methods: VJ allows the construction of end-to-end and end-to-side anastomoses. It consists of two metallic crowns fixed to the extremity of the two conduits so that vessel edges are joined layer by layer. There is no foreign material exposed to blood. In adult sheep both carotid arteries were prepared and severed. End-to-end anastomoses were performed using the VJ device on one side and the classical running suture technique on the other side. Animals were followed-up with Duplex-scan every 3 months and sacrificed after 12 months. Histopathological analysis was carried out. Results: In 20 animals all 22 sutureless anastomoses were successfully completed in less than 2min versus 6±3min for running suture. Duplex showed the occlusion of three controls and one sutureless anastomosis. Two controls and one sutureless had stenosis >50%. Histology showed very thin layer of myointimal hyperplasia (50±10Όm) in the sutureless group versus 300±27Όm in the control. No significant inflammatory reaction was detected. Conclusions: VJ provides edge-to-edge vascular repair that can be considered the most physiological way to restore vessel continuity. For the first time, in healthy sheep, an anastomotic device provided better results than suture techniqu
At the upper Palaeolithic â Mesolithic boundary : revision of the human remains from Riparo Fredian (Molazzana, Lucca, Italy)
Abstract: Pleistocene and early Holocene human fossils in Tuscany are very few and poorly described. Any new information is thus an important contribution to our knowledge of the peopling of this region. Here we present a revision of the human fossil remains from the Riparo Fredian, a site located in Garfagnana and first published by Boschian et al., (1995). The authors described the human remains of the site pointing out the presence of 39 isolated human teeth (19 maxillary and 20 mandibular) and âfragments of one adult humerus, of a child's femur and of a youngsterâs ulnaâ, considered as belonging to six individuals at least. A reanalysis of the human remains indicated that several specimens were incorrectly identified. It was thus deemed important to revise the identification of each fossil and their interpretation. The revision of human remains from Riparo Fredian has led to several changes in their anatomical identification with respect to the original publications. Of the 39 teeth previously described, the analysis revealed that two of them belonged to non-human animals, and 18 were mistakenly identified. A new, correct identification is provided for each of them. Also, two human teeth not described in the original papers have been identified. The anatomical identification of the post-cranial remains has been confirmed for two out of the three specimens. The minimum number of individuals, based on the dental remains, is confirmed as at least 5, but most probably 6, although with a different allocation of teeth to individual specimens. The age at death of the six individuals has also been reassessed, indicating the presence of two infants, two young adults and two mature adults
Hippocampal neuroplasticity and inflammation: relevance for multiple sclerosis
Cognitive impairment is very frequent during multiple sclerosis (MS), involving approximately 40â70% of the patients, with a profound impact on patient's life. It is now established that among the various central nervous system (CNS) structures involved during the course of MS, the hippocampus is particularly sensitive to the detrimental effects of neuroinflammation. Different studies demonstrated hippocampal involvement during MS, in association with depression and cognitive impairment, such as verbal and visuo-spatial memory deficits, even during the earlier phases of the disease. These cognitive alterations could represent the visible consequences of a hidden synaptic impairment. Indeed, neuronal and immune functions are intertwined and the immune system is able to modulate the efficacy of synaptic transmission and the induction of the main forms of synaptic plasticity, such as long term potentiation (LTP). Hippocampal synaptic plasticity has been studied during the last decades as the physiological basis of human learning and memory and its disruption can be associated with behavioral and cognitive abnormalities. The aim of the present work is to review the available evidence about the presence of hippocampal synaptic plasticity alterations in experimental models of MS, specifically during the course of experimental autoimmune encephalomyelitis (EAE) and to discuss their relevance with regard to human MS. Indeed, the failure of synapses to express plasticity during neuroinflammation could potentially lead to a progressive failure of the brain plastic reserve, possibly contributing to disability progression and cognitive impairment during MS
Unveiling hidden active nuclei in MaNGA star-forming galaxies with HeII4686 line emission
Nebular HeII4686\AA~line emission is useful to unveil active
galactic nuclei (AGN) residing in actively star-forming (SF) galaxies,
typically missed by the standard BPT classification. Here we adopt the HeII
diagnostic to identify hidden AGN in the Local Universe using for the first
time spatially-resolved data from the Data Release 15 of the Mapping Nearby
Galaxies at APO survey (MaNGA DR15). By combining results from HeII and BPT
diagnostics, we overall select 459 AGN host candidates (10% in MaNGA
DR15), out of which 27 are identified as AGN by the HeII diagram only. The
HeII-only AGN population is hosted by massive (M M)
SF Main Sequence galaxies, and on average less luminous than the BPT-selected
AGN. Given the HeII line faintness, we revisit our census accounting for
incompleteness effects due to the HeII sensitivity limit of MaNGA. We thus
obtain an overall increased fraction (11%) of AGN in MaNGA compared to the
BPT-only census (9%), which further increases to 14% for galaxies more massive
than M; interestingly, on the SF Main Sequence the increase
is by about a factor of 2. A substantial number of AGN in SF galaxies points to
significant, coeval star formation and black hole accretion, consistently with
results from hydrodynamical simulations and with important implications on
quenching scenarios. In view of exploring unprecedented high redshifts with
JWST and new ground-based facilities, revisiting the standard BPT
classification through novel emission-line diagnostics is fundamental to
discover AGN in highly SF environments.Comment: 13 pages, 12 figures. Accepted for publication in MNRA
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