Optimal Design for Vibration Mitigation of a Planar Parallel Mechanism for a Fast Automatic Machine

This work studies a planar parallel mechanism installed on a fast-operating automatic machine. In particular, the mechanism design is optimized to mitigate experimentally-observed vibrations. The latter are a frequent issue in mechanisms operating at high speeds, since they may lead to low-quality products and, ultimately, to permanent damage to the goods that are processed. In order to identify the vibration cause, several possible factors are explored, such as resonance phenomena, elastic deformations of the components, and joint deformations under operation loads. Then, two design optimization are performed, which result in a significant improvement in the vibrational behaviour, with oscillations being strongly reduced in comparison to the initial design

A multi-disciplinary approach combining geological, geomorphological and geophysical data for mapping the susceptibility to sinkholes

The Salento region of southern Italy has a great number of active sinkholes, related to both natural and anthropogenic cavities. The presence of sinkholes is at the origin of several problems to the built-up environment, due to the increasing population growth and development pressures. In such a context, the detection of cavities, and therefore the assessment of the sinkhole hazard presents numerous difficulties. Multidisciplinary – approach, comprising geological, geomorphological and geophysical analyses, is therefore necessary to obtain comprehensive knowledge of the complex phenomena in karstic areas. Geophysical methods can also be of great help to identify and map the areas at higher risk of collapse. In this case it is important to identify the features related to the underground voids, likely evolving to sinkholes, by contrasts in physical properties such as density, electrical resistivity, and so on, with the surrounding sediments. At the same time, identification of the presence of sinkholes by geophysical methods has to adapt to the different geological conditions, so that there is not the possibility to use the same techniques everywhere. At this aim, the present paper illustrates the advantages of integrating geological and geomorphological surveys with surface geophysical techniques such as seismic, geoelectrical and ground penetrating radar methods for the identification of sinkhole-prone areas. The present work illustrates the results concerning a sinkhole system at Nociglia (inland Salento, southeastern Italy) where the shallow phreatic speleogenesis operates close to the water table level with formation of karst conduits and proto-caves whose evolution occurs through successive roof collapse, formation of wide caverns and sinkhole development at the surface. All of this creates serious problems to the nearby infrastructures, including a province road that has often been threatened by the sinkhole development. Geological and geomorphological analyses provided the basic data necessary to constitute a framework to understand the mechanism of sinkholes formation and at the same time to guide the choice of the most suitable geophysical techniques, and the interpretation of the measurements as well. The different geophysical methods are eventually discussed in order to point out their ability to locate the main karst conduits and caves

Recent developments in the reduction of oxidative stress through antioxidant polymeric formulations

Reactive oxygen and nitrogen species (RONS) are produced endogenously in our body, or introduced through external factors, such as pollution, cigarette smoke, and excessive sunlight exposure. In normal conditions, there is a physiological balance between pro-oxidant species and antioxidant molecules that are able to counteract the detrimental effect of the former. Nevertheless, when this homeostasis is disrupted, the resulting oxidative stress can lead to several pathological conditions, from inflammation to cancer and neurodegenerative diseases. In this review, we report on the recent developments of different polymeric formulations that are able to reduce the oxidative stress, from natural extracts, to films and hydrogels, and finally to nanoparticles (NPs)

enabling access to cultural heritage for the visually impaired an interactive 3d model of a cultural site

Abstract We have developed low cost interactive 3D models that improve access to architectural details of cultural sites for all, including people with vision impairments. Our approach uses rapid prototyping and 3D printing along with a very small single-board computer for automating user interaction. As a case study, we developed a prototype model of "Piazza dei Miracoli" (Pisa, Italy), the famous square where the Leaning Tower is located. The system is a combination of tactile information with audio descriptions to enable potential users to explore the artifact autonomously. We exploited low-cost and partially open-source technologies, thus rendering our system easily replicable. We evaluated the interactive system with a group of eight completely blind and partially sighted users. Our user test confirmed the validity of our approach: (1) the three-dimensional models and the tactile reproduction of details obtained via a low-cost 3D printing solution are well perceived by touch; (2) the semantic aural information activated via perceptible buttons on demand and the different content levels for the audio tracks are suitable for an interactive, autonomous and satisfying exploration

Management of cutaneous discomfort in patients with scleroderma: a clinical trial.

Systemic sclerosis (scleroderma) is a disease of unknown cause, the hallmark of which is induration of the skin. This bad condition of the skin influences negatively the quality of life of patients with scleroderma. The aim of the study was to verify the efficacy of two formulations, specifically designed to wash, moisturize and soothe the scleroderma skin. An independent, randomized, double blind, controlled trial was conducted in the Department of Rheumatology of "A. Galateo" Hospital in San Cesario di Lecce. Forty-six women affected by scleroderma, and treated with Iloprost every month, were divided into two groups: group 1 followed a specific treatment with cleansing formulation only, group 2 followed a combined treatment with the cleansing solution and the moisturizing solution. In addition, a third group was evaluated: 14 women, who did not undergo intravenous Iloprost therapy, were treated simultaneously with the cleansing formulation and the moisturizing formulation. The three treatments lasted for 4 weeks. Reduction in trans epidermal water loss (TEWL), increase in moisturization of the stratum corneum, reduction in Skin Score and improvement in quality of life were assessed. Very significant improvement in quality of life occurred in each group. Group 2 obtained very significant improvement in hydration and reduction in skin score and TEWL. The study showed that the daily use of both formulations proved to be effective in washing, hydrating and soothing the skin of patients with scleroderma, especially in association with Iloprost therapy

Application of 3D visualization techniques in the analysis of GPR data for archaeology

In this work, some results of a GPR survey carried out in a 10000 m2 large archaeological site, located in Lecce (Italy) near to a necropolis dating from the Messapian to the Roman imperial age, are reported. After a preliminary survey, performed on the entire area along parallel 1 m spaced profiles using a 200 MHz and a 500 MHz antenna in single-fold continuous mode, some smaller areas were selected, where the survey was repeated decreasing the profile spacing down to 0.50 m for the lower frequency antenna and to 0.25 m for the higher one. For two selected zones (D and B) the processed data were visualized in 3D space not only by the standard time slice technique, but also by two recently proposed approaches, namely by iso-amplitude surfaces of the complex trace amplitude and by 3D projection of energy and envelope stacks. The immediacy in revealing the spatial positioning of highly reflecting bodies, such as the anomaly interpreted as an old refilled cistern in zone D, makes 3D visualization techniques very attractive in archaeological applications of GPR. Their sensitivity to the signal/noise ratio is, on the other hand, highlighted by the quite poor performance in zone B, where the only reliable result provided by all the techniques was the soil/bedrock reflection, whereas none of them could effectively enhance the visibility of weak dipping reflections noted on 2D sections and probably related to fractures or bedding planes in the calcarenitic basement. The performance of the various techniques in these two different situations allowed insights into their main advantages and drawbacks to be gained

Wiggle-Match dating of wooden samples from iron age sites in Northern Italy

Archaeological excavations carried out at the sites of Laion/Lajen (Bolzano/Bozen) and Stufles-Oberegger (Bressanone/Brixen) in northern Italy uncovered well-preserved wooden samples in cultural layers archaeologically dated to the Iron Age. From the 2 sites, different wooden samples were recovered that were well preserved enough to allow clear identification of the tree species and of the ring structure. Among the different wooden samples, 2 were selected for radiocarbon analyses: from Laion/Lajen, a beam with an unbroken sequence of 158 rings; from Stufles-Oberegger, a combusted trunk with a sequence of 217 rings. Both samples were identified as Larix decidua species. From each sequence, single rings were selected and submitted for accelerator mass spectrometry (AMS) 14C dating analysis at CEDAD. Conventional 14C ages were then calibrated to calendar ages using the IntCal04 atmospheric data set, while the statistical constraints resulting from the defined ring sequence were used to develop a wiggle-matching approach by making use of the Bayesian analysis functions available in OxCal. The obtained results are an important contribution in refining the chronology of the studied sites

Nedd4-2 haploinsufficiency causes hyperactivity and increased sensitivity to inflammatory stimuli

Nedd4-2 (NEDD4L in humans) is a ubiquitin protein ligase best known for its role in regulating ion channel internalization and turnover. Nedd4-2 deletion in mice causes perinatal lethality associated with increased epithelial sodium channel (ENaC) expression in lung and kidney. Abundant data suggest that Nedd4-2 plays a role in neuronal functions and may be linked to epilepsy and dyslexia in humans. We used a mouse model of Nedd4-2 haploinsufficiency to investigate whether an alteration in Nedd4-2 levels of expression affects general nervous system functions. We found that Nedd4-2 heterozygous mice are hyperactive, have increased basal synaptic transmission and have enhanced sensitivity to inflammatory pain. Thus, Nedd4-2 heterozygous mice provide a new genetic model to study inflammatory pain. These data also suggest that in human, SNPs affecting NEDD4L levels may be involved in the development of neuropsychological deficits and peripheral neuropathies and may help unveil the genetic basis of comorbidities

Porcine sclera as a model of human sclera for in vitro transport experiments: histology, SEM, and comparative permeability

PURPOSE: To evaluate porcine sclera as a model of human sclera for in vitro studies of transscleral drug delivery of both low and high molecular weight compounds. METHODS: Human and porcine scleras were characterized for thickness and water content. The tissue surface was examined by scanning electron microscopy (SEM), and the histology was studied with hematoxylin-eosin staining. Comparative permeation experiments were performed using three model molecules, acetaminophen as the model compound for small molecules; a linear dextran with a molecular weight of 120 kDa as the model compound for high molecular weight drugs; and insulin, which was chosen as the model protein. Permeation parameters such as flux, lag time, and permeability coefficient were determined and compared. RESULTS: Human and porcine scleras have a similar histology and collagen bundle organization. The water content is approx 70% for both tissues while a statistically significant difference was found for the thickness, porcine sclera being approximately twofold thicker than human sclera. Differences in thickness produced differences in the permeability coefficient. In fact, human sclera was found to be two to threefold more permeable toward the three molecules studied than porcine sclera. CONCLUSIONS: The results obtained in the present paper prove that porcine sclera can be considered a good model for human sclera for in vitro permeation experiments of both low and high molecular weight compounds. In fact, if the different tissue thickness is taken into account, comparable permeability was demonstrated. This suggests a possible use of this model in the evaluation of the transscleral permeation of new biotech compounds, which currently represent the most innovative and efficient therapeutic options for the treatment of ocular diseases

Serum Squamous Cell Carcinoma Antigen-Immunoglobulin M complex levels predict survival in patients with cirrhosis

Complications of chronic liver diseases - particularly hepatocellular carcinoma (HCC) - are a major cause of mortality worldwide. Several studies have shown that high or increasing levels of serum Squamous Cell Carcinoma Antigen-Immunoglobulin M complex (SCCA-IgM) are associated with development of HCC in patients with advanced liver disease and worse survival in patients with liver cancer. The aim of the present study was to assess, in patients with advanced liver disease, differences in long-term clinical outcomes in relation to baseline levels of serum SCCA-IgM. Ninety one consecutive outpatients with liver cirrhosis of different etiologies, without hepatocellular carcinoma at presentation, were enrolled from April 2007 to October 2012 in a prospective study. For a median time of 127 months, patients were bi-annually re-evaluated. SCCA-IgM complex levels were determined with a validated enzyme-linked immunosorbent assay. The results provided evidence that serum SCCA-IgM is a predictor of overall survival. The best cut-off to discriminate both HCC-free and overall survival rates was 120\u2009AU/mL. Patients with baseline values higher than this threshold showed a substantial increase in both HCC incidence rate and all-cause mortality rate. In conclusion, a single measurement of serum SCCA-IgM helps to identify those patients with liver cirrhosis with increased risks of HCC development and mortality