2,276 research outputs found
Anterior cervical discectomy and fusion with ROI-C peek cage: cervical alignment and patient outcomes
OBJECTIVE:
The intersomatic cage ROI-C one is a new promising system in anterior cervical discectomy with subsequent fusion.
METHODS:
Patients were studied prospectively. ROI-C cages were used in consecutive 32 patients. Intraoperative parameters, clinical features and dysphagia scores were recorded. Radiographs evaluated the height of intervertebral space, the cervical Cobb angle and implant positioning. Data were collected on the last day of hospital stay, at 6 weeks, at 3, 6, 12 and 24 months.
RESULTS:
A total of 32 cages were implanted. One patient had transient dysphagia. The intervertebral height and the cervical Cobb angle were significantly improved at 24 months follow-up (P < 0.05). Compared to pre-operatively, visual analog scale pain score and neck pain and disability scale were reduced at 1-month follow-up without change during subsequent follow-up.
CONCLUSIONS:
This is the first prospective study on ROI-C cages. Although this is a preliminary assessment, the ROI-C cage may represent an excellent alternative to other devices or simple bone graft
An Enhanced Fractional Order Model of Ionic Polymer-Metal Composites Actuator
Ionic polymer-metal composites (IPMCs) are electroactive polymers which transform the mechanical forces into electric signals and vice versa. The paper proposes an enhanced fractional order transfer function (FOTF) model for IPMC membrane working as actuator. In particular the IPMC model has been characterized through experimentation, and a more detailed structure of its FOTF has been determined via optimization routines. The minimization error was attained comparing the simple genetic algorithms with the simplex method and considering the error between the experimental and model derived frequency responses as cost functions
Spontaneous Meckel\u2032s cave hematoma: A rare cause of trigeminal neuralgia
Background: The most common etiology of classic trigeminal neuralgia (TN) is vascular compression. However, other causes must be considered. Among these, spontaneous hematoma of the Meckel\u2032s cave (MC) causing symptomatic TN is very rare. Case Description: We present the case of a 60-year-old woman with a 2-month history of left TN and diplopia. Neuroradiological examinations revealed a well-defined hematoma in the left MC. The patient underwent surgical decompression with a progressive neurological improvement. Conclusion: Despite the number of lesions potentially affecting the MC, spontaneous hemorrhage is rare but should be taken into account in the differential diagnosis
Cavernous malformation of the optic chiasm: An uncommon location
Cavernous malformations (CMs) of the optic chiasm are rare lesions often presenting with acute chiasmal syndrome or a progressive visual loss. The case of a 48-year-old female with an intrachiasmatic CM is presented
Intraoperative microvascular Doppler monitoring of blood flow within a spinal dural arteriovenous fistula: a precious surgical tool. Case report.
The authors describe a case of spinal arteriovenous fistula (AVF) treated by a microvascular Doppler-assisted surgical interruption of the arterialized vein. Microvascular Doppler monitoring represents a valid, widely available, noninvasive tool that enables identification, through flow spectrum analysis, of components of this type of vascular malformation. In this case because the location of the fistula was identified prior to opening the dura only minimally invasive surgery was required. Direct recordings of the arterialized draining vein and the nidus of the fistula demonstrated a pathological spectrum caused by the arterial supply and the disturbed venous outflow in which a high-resistance flow pattern and low diastolic flow resembling an arterial-like flow velocity were observed. The fistula was obliterated by interruption of the draining vein, and Doppler measurements provided information on flow velocity changes in the medullary veins from an arterial to a venous pattern. The absence of any residual flow in the AVF confirmed successful hemodynamic treatment. Intraoperative microvascular Doppler recording during surgical closure of spinal AVF is a widely available and reliable monitoring modality that helps to produce excellent clinical results
Recruitment of visual cortex for language processing in blind individuals: A neurobiological model
After sensory deprivation, the visual cortex is functionally recruited into non-visual cognitive language and semantic processing. Why this functional organization takes place and how its underlying mechanisms work at the neuronal circuit level is still unclear. Here, we use a biologically constrained network model implementing anatomical structure, neurophysiological function and connectivity of the fronto-tempo-occipital cortex to simulate word-meaning acquisition in visually deprived and undeprived (âhealthy controlâ) brains. Whereas in the âundeprivedâ simulations only words denoting visual entities grew into the visual domain, the âblindâ models unexpectedly produced word-related neuronal circuits extending into visual cortex for all semantic categories (and especially for those carrying action-related meaning). Additionally, during word recognition, the blind model showed long-lasting spiking neural activity compared to the sighted model, a sign for enhanced verbal working memory due to the additional neural recruitment. Three factors are crucial for explaining this deprivation-related growth: (i) changes in the networkâs activity balance brought about by the absence of uncorrelated sensory input, (ii) the connectivity structure of the network, and (iii) Hebbian correlation learning. By offering a neurobiological account for neural changes of language processing due to visual deprivation, our model bridges the gap between cellular-level mechanisms and system-level language function in blind humans
Theory of mind in animals : current and future directions
C.K. was supported by European Commission Marie SkĆodowskaâCurie fellowship MENTALIZINGORIGINS and J.C. by European Research Council Synergy grant 609819 SOMICS.Theory of mind (ToM; a.k.a., mind-reading, mentalizing, mental-state attribution, and perspective-taking) is the ability to ascribe mental states, such as desires and beliefs, to others, and it is central to the unique forms of communication, cooperation, and culture that define our species. As a result, for 40 years, researchers have endeavored to determine whether ToM is itself unique to humans. Investigations in other species (e.g., apes, monkeys, corvids) are essential to understand the mechanistic underpinnings and evolutionary origins of this capacity across taxa, including humans. We review the literature on ToM in nonhuman animals, suggesting that some species share foundational social cognitive mechanisms with humans. We focus principally on innovations of the last decade and pressing directions for future work. Underexplored types of social cognition have been targeted, including ascription of mental states, such as desires and beliefs, that require simultaneously representing one's own and another's conflicting motives or views of the world. Ongoing efforts probe the motivational facets of ToM, how flexibly animals can recruit social cognitive skills across cooperative and competitive settings, and appropriate motivational contexts for comparative inquiry. Finally, novel methodological and empirical approaches have brought new species (e.g., lemurs, dogs) into the lab, implemented critical controls to elucidate underlying mechanisms, and contributed powerful new techniques (e.g., looking-time, eye-tracking) that open the door to unexplored approaches for studying animal minds. These innovations in cognition, motivation, and method promise fruitful progress in the years to come, in understanding the nature and origin of ToM in humans and other species.PostprintPeer reviewe
Improving natural ventilation in renovated free-stall barns for dairy cows: Optimized building solutions by using a validated computational fluid dynamics model
Natural ventilation is the most used system to create suitable conditions, removing gases, introducing oxygen in livestock buildings. Its efficiency depends on several factors and above all on the number, the dimensions and the position of wall openings and internal layout of livestock buildings. The aim of this research was to develop optimized layout solutions for improving natural ventilation effectiveness in free-stall barns for dairy cows by using a CFD approach. A validated computational fluid dynamics (CFD) model was applied in a case study which is highly representative of building interventions for renovating the layout of free-stall barns for dairy cows located in an area of the Mediterranean basin. Firstly, dairy cow behaviour was analysed by visual examination of time-lapse video-recordings. Then, simulations were carried out by using the validated CFD model and changing the position of internal and external building elements (i.e., internal office and external buildings for milking) in order to find the best condition for the thermal comfort of the animals. The results showed that the best conditions were recorded for a new configuration of the building in terms of air velocity distribution within the resting area, the service alley and the feeding alley for dairy cows, and in the pens for calves. In this new layout, the office areas and the north-west wall openings were located by mirroring them along the transversal axis of the barn. Therefore, the CFD approach proposed in this study could be used during the design phase, as a decision support system aimed at improving the natural ventilation within the barn
Enhancing heat treatment efficacy for insect pest control: A case study of a CFD application to improve the design and structure of a flour mill
Heat treatment of the indoor environment of flour mills is an alternative technique to chemical fumigation for controlling insect pests. The aim of this research was to assess temperature distribution inside a flour mill during a heat treatment for insect pest control by computational fluid dynamics (CFD) modelling and simulation. The model was validated by using the average values of experimental data acquired during a heat treatment carried out in a flour mill, which is representative of the building materials and techniques used in the milling industry of South Italy. Simulations were carried out in steady-state conditions, and simulated data were validated by the average values of air and wall temperature measurements. Since the modelled temperature distribution in the mill fit the real one with a good accuracy (maximum error equal to 2.57 °C), the CFD model was considered reliable to simulate other operating conditions. Since it was observed that the internal surface temperatures of the mill were much lower than the value required for the success of the heat treatment, equal to 45 °C, the CFD model could be used for improving the effectiveness of heat treatments in the flour mill. Application of the proposed CFD model in the simulation of specific interventions could be aimed at improving both building performance and fan heaters' localisatio,n in order to find the best configuration
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