43 research outputs found

    The formation of the 8˚20’ N seamount chain, East Pacific rise

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    Near-axis seamounts provide a unique setting to investigate three-dimensional mantle processes associated with the formation of new oceanic crust and lithosphere. Here, we investigate the characteristics and evolution of the 8˚20’N Seamount Chain, a lineament of seamounts that extends ~ 175 km west of the East Pacific Rise (EPR) axis, just north of the fracture zone of the Siqueiros Transform Fault. Shipboard gravity, magnetic, and bathymetric data acquired in 2016 are utilized to constrain models of seamount emplacement and evolution. Geophysical observations indicate that these seamounts formed during four distinct episodes of volcanism coinciding with changes in regional plate motion that are also reflected in the development of intra-transform spreading centers (ITSCs) along the Siqueiros transform fault (Fornari et al. 1989; Pockalny et al. 1997). Although volcanism is divided into distinct segments, the magnetic data indicate continuous volcanic construction over long portions of the chain. Crustal thickness variations along the chain up to 0.75 km increase eastward, inferred from gravity measurements, suggest that plate reorganization has considerably impacted melt distribution in the area surrounding the Siqueiros-EPR ridge transform intersection. This appears to have resulted in increased volcanism and the formation of the 8˚20’N Seamounts. These findings indicate that melting processes in the mantle and subsequently the formation of new oceanic crust and lithosphere are highly sensitive to tectonic stress changes in the vicinity of fast spreading transform fault offsets

    Intraoperative imaging O-Arm™ in secondary surgical correction of post-traumatic orbital fractures

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    Abstract Purpose To determine the safety and efficacy of O-Arm™ intraoperative imaging in maxillofacial surgery of post-traumatic orbital fractures. In order to ensure correct placement of titanium plate, immediately after fixing, viewable, in the axial, sagittal and coronal images. Methods The authors evaluated 5 consecutive adult patients with orbital fractures who required a reoperation involving displacement of titanium mesh between January and December 2015. The displacement or incorrect positioning of titanium mesh was detected at post-operative CT scan or clinical neurological findings. Intraoperative O-Arm™ imaging was used for our patients who underwent secondary maxillofacial orbital fracture surgery due to the failure of first surgical approach. Results An eyelid incision was performed in order to obtain maximal exposure and minimizing cosmetic defects. Any previous fixation device was skeletonized and removed, any improperly reduced fracture was mobilized, reduced and refixated with 1.5 mm plates, screws and titanium mesh. The intra-operative O-Arm™ imaging technique was used at the end of the procedures. In 4 cases it confirmed the appropriateness of the newly obtained reconstruction, in 1 case a first scan showed a suboptimal result and the devices were correctly repositioned, guided by the O-Arm™ images. Conclusions Intraoperative O-Arm™ assisted craniofacial reconstruction surgery improves the assessment of neurovascular structure decompression, skeletal fragment identification, fixation procedures and for the correct re-establishment of facial symmetry in orbital floor fractures

    In hepatocellular carcinoma miR-221 modulates sorafenib resistance through inhibition of caspase-3\u2013mediated apoptosis

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    Purpose: The aberrant expression of miR-221 is a hallmark of human cancers, including hepatocellular carcinoma (HCC), and its involvement in drug resistance, together with a proved in vivo efficacy of anti-miR-221 molecules, strengthen its role as an attractive target candidate in the oncologic field. The discovery of biomarkers predicting the response to treatments represents a clinical challenge in the personalized treatment era. This study aimed to investigate the possible role of miR-221 as a circulating biomarker in HCC patients undergoing sorafenib treatment as well as to evaluate its contribution to sorafenib resistance in advanced HCC. Experimental Design: A chemically induced HCC rat model and a xenograft mouse model, together with HCC-derived cell lines were employed to analyze miR-221 modulation by Sorafenib treatment. Data from the functional analysis were validated in tissue samples from surgically resected HCCs. The variation of circulating miR-221 levels in relation to Sorafenib treatment were assayed in the animal models and in two independent cohorts of patients with advanced HCC. Results: MiR-221 over-expression was associated with Sorafenib resistance in two HCC animal models and caspase-3 was identified as its target gene, driving miR-221 anti-apoptotic activity following Sorafenib administration. Lower pre-treatment miR-221 serum levels were found in patients subsequently experiencing response to Sorafenib and an increase of circulating miR-221 at the two months assessment was observed in responder patients. Conclusions: MiR-221 might represent a candidate biomarker of likelihood of response to Sorafenib in HCC patients to be tested in future studies. Caspase-3 modulation by miR-221 participates to Sorafenib resistance

    History of spinal neurosurgery and spine societies

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    Historically, spine and spinal cord surgery have been an integral part of neurosurgery. It was always a part of the neurosurgery education and practically a significant part of neurosurgeons’ daily work. However, spine societies have mostly been pioneered by orthopedic spine surgeons. It’s only in the last 4 decades that neurosurgeons are also forming spine societies. The term “Neurospine” becomes more popular and used by many authors, institutions during the last decades, although it is not widely used in North America. There are specific reasons for its popularity: (1) It is like a combination of neurosurgery and spine surgery. Neurosurgeons widely prefer to use it. (2) It has a sense inside to remind patients that the spine is with neurological structures. “Neurospine Surgery” is also used in the sense of a combination of “neuroscience” and “spine”. There are at least 2 journals with this theme, i.e., “Neurospine” and “Journal of Neurosurgery Spine.” [1] In this paper, a brief history of spine surgery and spine-related societies is discussed. We aimed to create a global summary of neuro spine with spinal neurosurgeons’ perspectives from other parts of the world and comment on the world's current condition

    Euclid Near Infrared Spectrometer and Photometer instrument concept and first test results obtained for different breadboards models at the end of phase C

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    The Euclid mission objective is to understand why the expansion of the Universe is accelerating through by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision program with its launch planned for 2020 (ref [1]). The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (900- 2000nm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection subsystem based on a mosaic of 16 HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a mechanical focal plane structure made with molybdenum and aluminum. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This presentation describes the architecture of the instrument at the end of the phase C (Detailed Design Review), the expected performance, the technological key challenges and preliminary test results obtained for different NISP subsystem breadboards and for the NISP Structural and Thermal model (STM)

    Incidence and Epidemiology of Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

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    This review aims to search the epidemiology and incidence rates of thoracolumbar spine fractures. A systematic review of the literature of the last 10 years gave 586 results with incidence, and 387 results with epidemiology, of which 39 papers were analyzed. The review results were discussed and voted in 2 consensus meetings of the WFNS (World Federation of Neurosurgical Societies) Spine Committee. Out of 39 studies, 15 studies have focused on thoracolumbar trauma, remaining 24 studies have looked at all spine trauma. Most were retrospective in nature; few were prospective and multicenter. Some studies have focused on specific injuries. The annual incidence of TL fractures is about 30/100,000 inhabitants including osteoporotic fractures. There is a trend to increase the fractures in elderly population especially in developed countries, while an increase of motor vehicle accidents in developing countries. The mortality rate among male elderly patients is relatively high. The incidence of thoracolumbar spine fractures is increasing because of low-velocity falls in the elderly population. The main reasons are falls and traffic accidents. Learning the regional differences and some special forms of trauma such as extreme sports, war, and gunshot injuries will help the prevention of the thoracolumbar spine fractures

    Perforazione intestinale da ingestione accidentale di corpo estraneo

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    Usualmente i corpi estranei ingeriti accidentalmente attraversano il tratto gastroenterico senza recare alcun danno. Solo in rari casi sono responsabili di perforazione gastrointestinale. Gli oggetti più spesso incriminati sono ossi di pollo, spine di pesce e stuzzicadenti, mentre i pazienti a rischio sono ritardati mentali, alcolisti, tossicodipendenti, portatori di protesi dentarie, mangiatori rapidi o masticatori di stuzzicadenti. L’accidentalità dell’ingestione, in un soggetto con un quadro clinico spesso di dubbia interpretazione, e la scarsa sensibilità della diagnostica radiologica rimandano nella metà dei casi ad una diagnosi soltanto intraoperatoria di perforazione gastrointestinale da corpo estraneo. Inoltre, le opzioni chirurgiche variano dalla semplice estrazione dell’oggetto e rafia del difetto alla resezione intestinale colica, da eseguire in laparotomia o laparoscopia. Riportiamo l’esperienza di 3 casi di perforazione gastrointestinale da corpo estraneo diagnosticati all’atto operatorio imposto dal quadro peritonitico e trattati con estrazione del corpo estraneo e rafia in 2 pazienti (1 per via laparotomica; 1 per via laparoscopica); il terzo paziente è stato sottoposto a laparotomia esplorativa ed emicolectomia destra
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