167 research outputs found

    The Porcellini test: a novel test for accurate diagnosis of posterior labral tears of the shoulder: comparative analysis with the established tests

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    Questions/purposes: Although the posterior labral tears of the shoulder are known for their disabling clinical course, especially in overhead athletes, no clinical test used in isolation can diagnose it accurately in the preoperative period. We wanted to: (1) introduce “Porcellini test” with its radiological verification furnishing the anatomical basis of its mechanism; (2) determine its accuracy; and (3) compare its accuracy with that of the other established tests for diagnosing posterior labral tears of the shoulder. Methods: To determine the anatomical basis, we initially performed radiological verification of our test. Then, we evaluated its accuracy in a retrospective case-controlled study on 310 consecutive patients who underwent shoulder arthroscopic procedures at our hospital between January 2013 and December 2013. All patients were examined preoperatively for Porcellini test, and the presence of posterior labral tear was confirmed on arthroscopy. Later, in a cohort study on 91 consecutive patients who underwent shoulder arthroscopic procedures, we compared its accuracy with O’Brien’s test, the Kim test, the Jerk test, and the Load and Shift test. The accuracy was interpreted in terms of sensitivity, specificity, and predictive values. Results: The radiological verification conferred the anatomical basis for the mechanism of the Porcellini test. This new test showed high accuracy for posterior labral tears with sensitivity of 100 %, specificity of 99.3 %, the positive and negative predictive values of 92.6 and 100 %, respectively. Also, it had superior accuracy results than every other test. The interexaminer reliability for all test results was found to be >0.80. Conclusions: We propose “Porcellini test” as a simple, accurate, reproducible, and reliable test for the preoperative diagnosis of posterior labral tears of shoulder

    Neuromorphic Implementation of Orientation Hypercolumns

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    Neurons in the mammalian primary visual cortex are selective along multiple stimulus dimensions, including retinal position, spatial frequency, and orientation. Neurons tuned to different stimulus features but the same retinal position are grouped into retinotopic arrays of hypercolumns. This paper describes a neuromorphic implementation of orientation hypercolumns, which consists of a single silicon retina feeding multiple chips, each of which contains an array of neurons tuned to the same orientation and spatial frequency, but different retinal locations. All chips operate in continuous time, and communicate with each other using spikes transmitted by the address-event representation protocol. This system is modular in the sense that orientation coverage can be increased simply by adding more chips, and expandable in the sense that its output can be used to construct neurons tuned to other stimulus dimensions. We present measured results from the system, demonstrating neuronal selectivity along position, spatial frequency and orientation. We also demonstrate that the system supports recurrent feedback between neurons within one hypercolumn, even though they reside on different chips. The measured results from the system are in excellent concordance with theoretical predictions

    Sleep Macrostructure and NREM Sleep Instability Analysis in Pediatric Developmental Coordination Disorder

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    Developmental Coordination Disorder (DCD) is considered to be abnormal motor skills learning, identified by clumsiness, slowness, and/or motor inaccuracy impairing the daily-life activities in all ages of life, in the absence of sensory, cognitive, or neurological deficits impairment. The present research focuses on studying DCD sleep structure and Cyclic Alternating Pattern (CAP) parameters with a full overnight polysomnography and to study the putative correlations between sleep architecture and CAP parameters with motor coordination skills. The study was a cross-sectional design involving 42 children (26M/16F; mean age 10.12 ± 1.98) selected as a DCD group compared with 79 children (49M/30F; mean age 9.94 ± 2.84) identified as typical (no-DCD) for motor ability and sleep macrostructural parameters according to the MABC-2 and polysomnographic (PSG) evaluations. The two groups (DCD and non-DCD) were similar for age (p = 0.715) and gender (p = 0.854). More significant differences in sleep architecture and CAP parameters were found between two groups and significant correlations were identified between sleep parameters and motor coordination skills in the study population. In conclusion, our data show relevant abnormalities in sleep structure of DCD children and suggest a role for rapid components of A phases on motor coordination development

    Implementation of Olfactory Bulb Glomerular-Layer Computations in a Digital Neurosynaptic Core

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    We present a biomimetic system that captures essential functional properties of the glomerular layer of the mammalian olfactory bulb, specifically including its capacity to decorrelate similar odor representations without foreknowledge of the statistical distributions of analyte features. Our system is based on a digital neuromorphic chip consisting of 256 leaky-integrate-and-fire neurons, 1024 × 256 crossbar synapses, and address-event representation communication circuits. The neural circuits configured in the chip reflect established connections among mitral cells, periglomerular cells, external tufted cells, and superficial short-axon cells within the olfactory bulb, and accept input from convergent sets of sensors configured as olfactory sensory neurons. This configuration generates functional transformations comparable to those observed in the glomerular layer of the mammalian olfactory bulb. Our circuits, consuming only 45 pJ of active power per spike with a power supply of 0.85 V, can be used as the first stage of processing in low-power artificial chemical sensing devices inspired by natural olfactory systems

    Physical activity, ketogenic diet, and epilepsy: A mini-review

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    One-third of patients with epilepsy do not respond to antiepileptic drugs and may seek complementary and alternative treatment modalities. Dietary therapies, such as the ketogenic diet (KD), the modified Atkins diet, as well as the medium-chain triglyceride and the low glycaemic index diets, have been successfully implemented with some forms of epilepsy and are growing in utilization. The KD is a high-fat, low-protein, low-carbohydrate diet that has been used for various conditions for over a century. Insights into the mechanism of action of these diets may provide more targeted interventions for patients with epilepsy. Knowledge of these mechanisms is growing and includes neuroprotective effects on oxidative stress, neuroinflammation, potassium channels in the brain, and mitochondrial function. In this review, we explain the role of physical exercise and the ketogenic diet on epilepsy

    Scaling of a large-scale simulation of synchronous slow-wave and asynchronous awake-like activity of a cortical model with long-range interconnections

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    Cortical synapse organization supports a range of dynamic states on multiple spatial and temporal scales, from synchronous slow wave activity (SWA), characteristic of deep sleep or anesthesia, to fluctuating, asynchronous activity during wakefulness (AW). Such dynamic diversity poses a challenge for producing efficient large-scale simulations that embody realistic metaphors of short- and long-range synaptic connectivity. In fact, during SWA and AW different spatial extents of the cortical tissue are active in a given timespan and at different firing rates, which implies a wide variety of loads of local computation and communication. A balanced evaluation of simulation performance and robustness should therefore include tests of a variety of cortical dynamic states. Here, we demonstrate performance scaling of our proprietary Distributed and Plastic Spiking Neural Networks (DPSNN) simulation engine in both SWA and AW for bidimensional grids of neural populations, which reflects the modular organization of the cortex. We explored networks up to 192x192 modules, each composed of 1250 integrate-and-fire neurons with spike-frequency adaptation, and exponentially decaying inter-modular synaptic connectivity with varying spatial decay constant. For the largest networks the total number of synapses was over 70 billion. The execution platform included up to 64 dual-socket nodes, each socket mounting 8 Intel Xeon Haswell processor cores @ 2.40GHz clock rates. Network initialization time, memory usage, and execution time showed good scaling performances from 1 to 1024 processes, implemented using the standard Message Passing Interface (MPI) protocol. We achieved simulation speeds of between 2.3x10^9 and 4.1x10^9 synaptic events per second for both cortical states in the explored range of inter-modular interconnections.Comment: 22 pages, 9 figures, 4 table

    Nocturnal obstructive respiratory events severity is associated with low parental quality

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    Objective: Despite of the large prevalence of obstructive sleep apnea syndrome (OSAS) in pediatric age, numerous aspects of its impact on day life and on parental quality are still poor studied and considered in the clinical management. The study evaluated the stress levels and copying styles in a large sample of mother of children with OSAS. Method: 374 mothers of children affected by OSAS (mOSAS) were compared with a group of mothers of 421 neurotypical healthy children (mTDC) for stress perceived stress levels and for coping strategies. Subjects were recruited from Italian Regions in Sicily, Campania, Calabria and Umbria. Results: Among both groups mOSAS and mTDC no differences were reported for children age (p=0.340), children gender (p=0.956), similarly for age of mothers (p=0.188). Discussion: The perceived stress assessment in mOSAS showed higher rate of all parental stress scores of PSI-SF: Parental Distress domain (p<0.001), Difficult Child subscale (p<0.001), Parent-Child Dysfunctional Interaction domain (p<0.001) and Total Stress subscale score (p <0.001) than mTDC. Regarding the CISS evaluation, mOSAS reported higher scores in emotion-oriented (p<0.001) and avoidance-oriented (p <0.001) scales, while low task-oriented coping style scale score was reported (p<0.001) than mTDC. Pearson’s correlation analysis showed significant values for AHI, ODI and mdes SpO2 for each scale of PSI-SF questionnaire, particularly relevant for P-CDI (p<0.001), DC (p<0.001) and Stress Tot (p<0.001). Conclusion: Pediatric OSAS tends to cause maternal high stress levels than controls, with a significant correlation between respiratory parameters and all PSI-SF scores. Moreover, mothers of affected children showed significantly differences in emotion-oriented and avoidance-oriented coping tasks. The present study suggested the importance of evaluation for caregivers of children affected by OSAS

    OPN/CD44v6 overexpression in laryngeal dysplasia and correlation with clinical outcome

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    Laryngeal dysplasia is a common clinical concern. Despite major advancements, a significant number of patients with this condition progress to invasive squamous cell carcinoma. Osteopontin (OPN) is a secreted glycoprotein, whose expression is markedly elevated in several types of cancers. We explored OPN as a candidate biomarker for laryngeal dysplasia. To this aim, we examined OPN expression in 82 cases of dysplasia and in hyperplastic and normal tissue samples. OPN expression was elevated in all severe dysplasia samples, but not hyperplastic samples, with respect to matched normal mucosa. OPN expression levels correlated positively with degree of dysplasia (P=0.0094) and negatively with disease-free survival (P<0.0001). OPN expression was paralleled by cell surface reactivity for CD44v6, an OPN functional receptor. CD44v6 expression correlated negatively with disease-free survival, as well (P=0.0007). Taken as a whole, our finding identify OPN and CD44v6 as predictive markers of recurrence or aggressiveness in laryngeal intraepithelial neoplasia, and overall, point out an important signalling complex in the evolution of laryngeal dysplasia
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