DEVELOPMENT AND CHARACTERIZATION OF TIO2 COATINGS PREPARED BY ELECTRIC ARC-PHYSICAL VAPOUR DEPOSITION SYSTEM

TiO2 thin coatings were prepared, on various substrates, through evaporation of metallic titanium in an oxidizing atmosphere by modified electric arc physical vapor deposition (EA-PVD). The coatings were characterized chemically (by means of XPS and SIMS) and from the structural point of view (by means of XRD and Raman spectroscopy), in order to understand the factors which lead to homoge-neous coatings with high anatase content. The type of substrate is the main parameter that influence the crystal structure of the coatings: when stainless steel is used as substrate the coatings consist es-sentially of rutile, while on glass substrates coatings containing mainly anatase are obtained. The photocatalytic activity of the samples upon UVA irradiation was tested by using phenol as the target molecule. Phenol in the solution can be photocatalytically and rapidly degraded through the EA-PVD anatase TiO2 coatings

Visuomotor Cerebellum in Human and Nonhuman Primates

In this paper, we will review the anatomical components of the visuomotor cerebellum in human and, where possible, in non-human primates and discuss their function in relation to those of extracerebellar visuomotor regions with which they are connected. The floccular lobe, the dorsal paraflocculus, the oculomotor vermis, the uvula–nodulus, and the ansiform lobule are more or less independent components of the visuomotor cerebellum that are involved in different corticocerebellar and/or brain stem olivocerebellar loops. The floccular lobe and the oculomotor vermis share different mossy fiber inputs from the brain stem; the dorsal paraflocculus and the ansiform lobule receive corticopontine mossy fibers from postrolandic visual areas and the frontal eye fields, respectively. Of the visuomotor functions of the cerebellum, the vestibulo-ocular reflex is controlled by the floccular lobe; saccadic eye movements are controlled by the oculomotor vermis and ansiform lobule, while control of smooth pursuit involves all these cerebellar visuomotor regions. Functional imaging studies in humans further emphasize cerebellar involvement in visual reflexive eye movements and are discussed

Molecular identification of a retinal cell type that responds to upward motion

The retina contains complex circuits of neurons that extract salient information from visual inputs. Signals from photoreceptors are processed by retinal interneurons, integrated by retinal ganglion cells (RGCs) and sent to the brain by RGC axons. Distinct types of RGC respond to different visual features, such as increases or decreases in light intensity (ON and OFF cells, respectively), colour or moving objects1, 2, 3, 4, 5. Thus, RGCs comprise a set of parallel pathways from the eye to the brain. The identification of molecular markers for RGC subsets will facilitate attempts to correlate their structure with their function, assess their synaptic inputs and targets, and study their diversification. Here we show, by means of a transgenic marking method, that junctional adhesion molecule B (JAM-B) marks a previously unrecognized class of OFF RGCs in mice. These cells have asymmetric dendritic arbors aligned in a dorsal-to-ventral direction across the retina. Their receptive fields are also asymmetric and respond selectively to stimuli moving in a soma-to-dendrite direction; because the lens reverses the image of the world on the retina, these cells detect upward motion in the visual field. Thus, JAM-B identifies a unique population of RGCs in which structure corresponds remarkably to function

The accessory optic system: basic organization with an update on connectivity, neurochemistry, and function

The accessory optic system (AOS) is formed by a series of terminal nuclei receiving direct visual information from the retina via one or more accessory optic tracts. In addition to the retinal input, derived from ganglion cells that characteristically have large receptive fields, are direction-selective, and have a preference for slow moving stimuli, there are now well-characterized afferent connections with a key pretectal nucleus (nucleus of the optic tract) and the ventral lateral geniculate nucleus. The efferent connections of the AOS are robust, targeting brainstem and other structures in support of visual-oculomotor events such as optokinetic nystagmus and visual–vestibular interaction. This chapter reviews the newer experimental findings while including older data concerning the structural and functional organization of the AOS. We then consider the ontogeny and phylogeny of the AOS and include a discussion of similarities and differences in the anatomical organization of the AOS in nonmammalian and mammalian species. This is followed by sections dealing with retinal and cerebral cortical afferents to the AOS nuclei, interneuronal connections of AOS neurons, and the efferents of the AOS nuclei. We conclude with a section on Functional Considerations dealing with the issues of the response properties of AOS neurons, lesion and metabolic studies, and the AOS and spatial cognition

Pattern of striate cortical projections to the pretectal complex in the guinea pig

The primary goal of this study was to determine whether the striate cortex (Oc 1) of the guinea pig projects to the pretectal nucleus of the optic tract (NOT), the first postretinal station of the horizontal optokinetic pathway, and, if so, to analyze the anatomical organization of this cortico-NOT projection. Other goals of this investigation are to identify other pretectal nuclear projections from the visual cortex in the guinea pig, and to determine whether there is any visuotopic organization in this pathway. Axonal tracers (biocytin or 3H-leucine) were injected into the striate cortex (Oc 1), and the tissue processed with histochemical or light autoradiographic techniques. All subcortical terminal labeling is ipsilateral in the basal ganglia and thalamic nuclei. Furthermore, projections are traced to the ipsilateral brainstem, including two areas of the pretectal complex: (1) one in the NOT, extending in some cases to the adjacent lateral portion of the posterior pretectal nucleus (PPN), and (2) one in the pars compacta of the anterior pretectal nucleus (APNc). The terminal fields in the APN are consistently located rostrally in the dorsolateral portion of the nucleus, independently of the injection site in Oc 1, whereas in the NOT the terminal fields shift slightly after injections placed in different locations in the striate cortex. A correlation of the injection sites in Oc 1 and terminal fields in the NOT reveals a loose topographic organization in the cortico-NOT projection; accordingly, the rostrocaudal axis of the striate cortex projects to the lateromedial axis of the NOT, with a 90 degrees rotation, whereas lateral parts of the striate cortex project diffusely throughout the rostrocaudal extent of the NOT. These data show for the first time that the NOT in the guinea pig receives a substantial projection from the visual cortex. Given the fact that in the guinea pig the optokinetic nystagmus shares some of the characteristics found in cat and monkey (i.e., consistent initial fast rise in the slow phase velocity and reduced asymmetry in monocular stimulation), the present findings lend support to the hypothesis that a cortical input to the NOT is a necessary condition for these oculomotor properties to be present

Projections of the lateral terminal accessory optic nucleus of the common marmoset (Callitrix Jacchus)

The connections of the lateral terminal nucleus (LTN) of the accessory optic system (AOS) of the marmoset monkey were studied with anterograde 3H-amino acid light autoradiography and horseradish peroxidase retrograde labeling techniques. Results show a first and largest LTN projection to the pretectal and AOS nuclei including the ipsilateral nucleus of the optic tract, dorsal terminal nucleus, and interstitial nucleus of the superior fasciculus (posterior fibers); smaller contralateral projections are to the olivary pretectal nucleus, dorsal terminal nucleus, and LTN. A second, major bundle produces moderate-to-heavy labeling in all ipsilateral, accessory oculomotor nuclei (nucleus of posterior commissure, interstitial nucleus of Cajal, nucleus of Darkschewitsch) and nucleus of Bechterew; some of the fibers are distributed above the caudal oculomotor complex within the supraoculomotor periaqueductal gray. A third projection is ipsilateral to the pontine and mesencephalic reticular formations, nucleus reticularis tegmenti pontis and basilar pontine complex (dorsolateral nucleus only), dorsal parts of the medial terminal accessory optic nucleus, ventral tegmental area of Tsai, and rostral interstitial nucleus of the medial longitudinal fasciculus. Lastly, there are two long descending bundles: (1) one travels within the medial longitudinal fasciculus to terminate in the dorsal cap (ipsilateral >> contralateral) and medial accessory olive (ipsilateral only) of the inferior olivary complex. (2) The second soon splits, sending axons within the ipsilateral and contralateral brachium conjunctivum and is distributed to the superior and medial vestibular nuclei. The present findings are in general agreement with the documented connections of LTN with brainstem oculomotor centers in other species. In addition, there are unique connections in marmoset monkey that may have developed to serve the more complex oculomotor behavior of nonhuman primates

Solid particle erosion of thermal spray and physical vapour deposition thermal barrier coatings

Thermal barrier coatings (TBC) are used to protect hot path components of gas turbines from hot combustion gases. For a number of decades, in the case of aero engines TBCs are usually deposited by electron beam physical vapour deposition (EB-PVD). EB-PVD coatings have a columnar microstructure that guarantees high strain compliance and better solid particle erosion than PS TBCs. The main drawback of EB-PVD coating is the deposition cost that is higher than that of air plasma sprayed (APS) TBC. The major scientific and technical objective of the UE project TOPPCOAT was the development of improved TBC systems using advanced bonding concepts in combination with additional protective functional coatings. The first specific objective was to use these developments to provide a significant improvement to state-of-the-art APS coatings and hence provide a cost-effective alternative to EB-PVD. In this perspective one standard porous APS, two segmented APS, one EB-PVD and one PS-PVD (TM) were tested at 700 degrees C in a solid particle erosion jet tester, with EB-PVD and standard porous APS being the two reference systems.Tests were performed at impingement angles of 30 degrees and 90 degrees, representative for particle impingement on trailing and leading edges of gas turbine blades and vanes, respectively. Microquartz was chosen as the erodent being one of the main constituents of sand and fly volcanic ashes. After the end of the tests, the TBC microstructure was investigated using electron microscopy to characterise the failure mechanisms taking place in the TBC.It was found that PS-PVD (TM) and highly segmented TBCs showed erosion rates comparable or better than EB-PVD samples. (C) 2011 Elsevier B.V. All rights reserved

Socioeconomic burden of total joint arthroplasty for symptomatic hip and knee osteoarthritis in the Italian population: a 5-year analysis based on hospitalization records.

OBJECTIVE: To assess the burden of total joint arthroplasties (TJAs) performed for symptomatic hip and knee osteoarthritis (OA) in the Italian population. METHODS: We analyzed national hospitalizations and diagnosis-related group databases to compute incidence, annual percent change (APC), direct costs, and working days lost between 2001 and 2005 following TJA due to OA. RESULTS: In 2005, we recorded a total of 41,816 (APC +5.4; 95% confidence interval [95% CI] 5.1-5.8) and 44,051 (APC +13.4; 95% CI 13.1-13.8) hip and knee arthroplasties, respectively. Women represented the majority of patients undergoing TJA procedures (female:male ratio 1.7:1 for hip arthroplasties and 2.9:1 for knee arthroplasties). When analyzing the data by age groups, most of the patients were in the age groups 65-74 years and ≥75 years, although the highest increases were observed in those ages <65 years. Revisions accounted for 6,387 (APC +4.9; 95% CI 4.0-5.7) and 2,295 (APC +17.4; 95% CI 15.7-19.2) procedures for the hip and knee, respectively. Loss of working days in patients ages <65 years was estimated between 805,000 and 1 million days. Hospital costs increased from 741 million to 1 billion euros over the 5-year period (from 412 to 538 million euros for hip arthroplasties and from 329 to 517 million euros for knee arthroplasties). Rehabilitation costs increased from 228 to 322 million euros. Postoperative complications were estimated between 3.1 and 4.4 million euros. The average costs per patient were 16,835 and 15,358 euros for hip and knee arthroplasties, respectively. CONCLUSION: The socioeconomic burden of TJAs performed for symptomatic OA in Italy is remarkable and calls for the adoption of proper preventive measures

Socioeconomic burden of total joint arthroplasty for symptomatic hip and knee osteoarthritis in the Italian population: A 5-year analysis based on hospitalization records

Introduction. Our aim was to assess the burden of total joint arthroplasties (TJA) performed for symptomatic hip and knee osteoarthritis (OA) in the Italian population. Methods. We analyzed national hospitalizations and Diagnosis Related Groups (DRG) databases to compute incidence, annual percent increase (APC), direct costs, and working days lost between 2001 and 2005 following TJA due to OA. Results. In year 2005, we recorded a total of 41,816 (APC:+5.4; 95%CI:5.1-5.8) and 44,051 (+13.4; 95%CI:13.1-13.8) hip and knee arthroplasties, respectively. Women represented the vast majority of patients undergoing TJA procedures (female/male ratio: 1.7 for hip and 2.9 for knee arthroplasties). When analyzing data by age groups, most of the patients were in the age groups of 65-74 and >75 years old, although the highest increases were observed <65 years of age. Revisions accounted for 6,387 (APC: +4.9; 95%CI: 4.0-5.7) and 2,295 (APC: +17.4; 95%CI: 15.7-19.2) procedures for hip and knee, respectively. Loss of working days in patients <65 was estimated between 805,000 and 1 million days. Hospital costs increased from 741 million to 1 billion Euros over the 5-year period (412 to 538 million for hip and 329 to 517 million for knee arthroplasties). Rehabilitation costs increased from 229 to 323 million Euros. Post-operative complications were estimated between 3.1 and 4.5 million Euros, with average cost per patient being 16,835 and 15,358 euros for hip and knee arthroplasty, respectively. Conclusion. Socio-economic burden of TJA performed for symptomatic osteoarthritis in Italy is remarkable and calls for the adoption of proper preventive measures. © 2012 by the American College of Rheumatology