25 research outputs found

    Lava flow hazard at Mount Etna (Italy): new data from a GIS-based study

    No full text
    Invasion of inhabited areas and destruction of human property by lava flows represents the greatest volcanic hazard at Mount Etna (Italy) in the short term, based on the character of the historically documented eruptions of the volcano. Virtually all eruptions of Etna produce lava flows, which are more likely to cause damage when emitted from flank vents. Since 1600, more than sixty eruptions have occurred on the flanks of Etna. About half of these caused damage to, or destruction of, human property, dwellings and infrastructures, and at least two destroyed entire population centers. We present a quantitative analysis and evaluation of a new database containing numerical volcanological parameters of each post-1600 eruption, which allows us to quantify the hazard from future eruptions and to create a preliminary hazard zonation map divided into six zones. A total area of nearly 1400 km2 is considered vulnerable, which is home to >900,000 people. The greatest hazard is from voluminous and/or low-altitude flank eruptions, which during the historical period have occurred at irregular intervals of 120-400 years, the most recent in 1669. In the future, eruptions at higher elevations will occur much more frequently, at intervals of a few months to several decades, and many will cause damage in relatively limited areas. A recent increase in the intensity and frequency of eruptions indicate that the Etna volcanic system is presently more dynamic than during the past 330 years, and low-altitude flank eruptions have to be considered a realistic possibility for the near future

    Lava flow hazard at Mount Etna (Italy): new data from a GIS-based study

    No full text
    Invasion of inhabited areas and destruction of human property by lava flows represents the greatest volcanic hazard at Mount Etna (Italy) in the short term, based on the character of the historically documented eruptions of the volcano. Virtually all eruptions of Etna produce lava flows, which are more likely to cause damage when emitted from flank vents. Since 1600, more than sixty eruptions have occurred on the flanks of Etna. About half of these caused damage to, or destruction of, human property, dwellings and infrastructures, and at least two destroyed entire population centers. We present a quantitative analysis and evaluation of a new database containing numerical volcanological parameters of each post-1600 eruption, which allows us to quantify the hazard from future eruptions and to create a preliminary hazard zonation map divided into six zones. A total area of nearly 1400 km2 is considered vulnerable, which is home to >900,000 people. The greatest hazard is from voluminous and/or low-altitude flank eruptions, which during the historical period have occurred at irregular intervals of 120-400 years, the most recent in 1669. In the future, eruptions at higher elevations will occur much more frequently, at intervals of a few months to several decades, and many will cause damage in relatively limited areas. A recent increase in the intensity and frequency of eruptions indicate that the Etna volcanic system is presently more dynamic than during the past 330 years, and low-altitude flank eruptions have to be considered a realistic possibility for the near future.Published189-2081.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani3.5. Geologia e storia dei sistemi vulcanici3.6. Fisica del vulcanismoreserve

    Mechanical properties of a cultured osteoblast

    No full text

    Laparoscopy in the management of impalpable testis (Series of 64 Cases)

    No full text
    Background: The undescended testis represents one of the most common disorders of childhood. Laparoscopy has been widely used both in the diagnosis and treatment of non-palpable testis. In this study, we investigated and evaluated the usefulness of laparoscopy in the diagnosis and treatment of no palpable testis. Patients and Methods: From January 2003 to January 2008, we used laparoscopy in the management of 64 patients with 75 impalpable testes. Their ages varied from 1 to 15 years (median age = 4.6 years). The site and the size of the testes were localised by abdominopelvic ultrasonography in all 64 children for accurate diagnosis. One stage laparoscopic orchiopexy was performed in 26 testes, staged Fowler-Stephens orchiopexy was underwent in 17 testes, while laparoscopic orchidectomy was done in 5 testes. Follow-up by clinical examination and colour Doppler ultrasound was performed in every patient who underwent orchiopexy. Results: There were 11 patients with bilateral non-palpable testes. The overall diagnostic agreement of ultrasound with laparoscopy was seen in only 16 out of 75 testes (21.3%). The results of diagnostic laparoscopy were varied and showed various pathological. Conditions and positioned of the testes, such as 20 low intra-abdominal testes (26.6%), 17 testes were high intra-abdominal (22.7%), and 18 testes (24%) entered the inguinal canal. Associated inguinal hernia was present in 4 patients. After a mean follow-up period of 26 months (6 months – 5 years), all testes were in the bottom of the scrotum except 3 testes were retracted to the neck of the scrotum and atrophy of the testis occurred in 2 patients (2.7%). Conclusion: Laparoscopy has proven to be the only diagnostic modality where the findings provide a clear dependable direction for the definitive management of impalpable testes, so it allows an accurate diagnosis and definitive treatment in the same sitting

    Visible-light-induced photocatalytic and antibacterial activity of TiO2 codoped with nitrogen and bismuth: new perspectives to control implant-biofilm-related diseases

    No full text
    Biofilm-associated diseases are one of the main causes of implant failure. Currently, the development of process and focuses on the creation of surfaces with implant surface treatment goes beyond the osseointegration antimicrobial action and with the possibility to be re-activated (i.e., light source activation). Titanium dioxide (TiO2), an excellent photocatalyst used for photocatalytic antibacterial applications, could be a great alternative, but its efficiency is limited to the ultraviolet (UV) range of the electromagnetic spectrum. Since UV radiation has carcinogenic potential, we created a functional TiO2 coating codoped with nitrogen and bismuth via the plasma electrolytic oxidation (PEO) of titanium to achieve an antibacterial effect under visible light with re-activation potential. A complex surface topography was demonstrated by scanning electron microscopy and three-dimensional confocal laser scanning microscopy. Additionally, PEO-treated surfaces showed greater hydrophilicity and albumin adsorption compared to control, untreated titanium. Bismuth incorporation shifted the band gap of TiO2 to the visible region and facilitated higher degradation of methyl orange (MO) in the dark, with a greater reduction in the concentration of MO after visible-light irradiation even after 72 h of aging. These results were consistent with the in vitro antibacterial effect, where samples with nitrogen and bismuth in their composition showed the greatest bacterial reduction after 24 h of dual-species biofilm formation (Streptococcus sanguinis and Actinomyces naeslundii) in darkness with a superior effect at 30 min of visible-light irradiation. In addition, such a coating presents reusable photocatalytic potential and good biocompatibility by presenting a noncytotoxicity effect on human gingival fibroblast cells. Therefore, nitrogen and bismuth incorporation into TiO2 via PEO can be considered a promising alternative for dental implant application with antibacterial properties in darkness, with a stronger effect after visible-light application11201818618202COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2017/00314-6; 2017/01320-0; 2016/11470-6This study was financed by the State of Sao Paulo Research Foundation (FAPESP) (grant numbers 2017/00314-6, 2017/01320-0 and 2016/11470-6) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001. We thank the Oral Biochemistry Lab at Piracicaba Dental School, University of Campinas, for providing their microbiology facility and the Brazilian Nanotechnology National Laboratory (LNNano) at the Brazilian Center of Research in Energy and Materials (CNPEM) for the CLSM, XPS, and XRD facilities. We also thank Professor Dr Ricardo Armini Caldas for his contribution to the elaboration of a table of contents graphic desig

    Functionalization of an experimental Ti-Nb-Zr-Ta alloy with a biomimetic coating produced by plasma electrolytic oxidation

    No full text
    This study developed an experimental quaternary titanium (Ti) alloy and evaluated its surface properties and electrochemical stability. The viability for a biofunctional surface treatment was also tested. Ti-35Nb-7Zr-5Ta (wt%) alloy was developed from pure metals. Commercially pure titanium (cpTi) and Ti-6Al-4V were used as controls. All groups had two surface conditions: untreated (machined surface) and modified by plasma electrolytic oxidation (PEO) (treated surface). The experimental alloy was successfully synthesized and exhibited β microstructure. PEO treatment created a porous surface with increased roughness, surface free energy, hardness and electrochemical stability (p < 0.05). For the machined surfaces, the Ti-Nb-Zr-Ta alloy presented the lowest hardness and elastic modulus (p < 0.05) and displayed greater polarization resistance relative to cpTi. Only PEO-treated cpTi and Ti-Al-V alloys exhibited anatase and rutile as crystalline structures. The β experimental Ti-Nb-Zr-Ta alloy seems to be a good alternative for the manufacture of dental implants, since it presents elastic modulus closer to that of bone, feasibility for surface treatment, electrochemical stability and absence of toxic elements77010381048FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2016/11470-6; 2017/01320-0This work was supported by the São Paulo State Research Foundation (FAPESP), Brazil (grant numbers 2016/11470-6 and 2017/01320-0). The authors express their gratitude to Jamille Altheman for her contribution and support at the Laboratory of Technological Plasmas at Univ. Estadual Paulista (UNESP), to Dr Richard Landers and Rita Vinhas from the University of Campinas (Institute of Physics Gleb Wataghin) for providing the XPS facility, to Dr Mathew T Mathew from the University of Illinois at Rockford (College of Medicine at Rockford, Department of Biomedical Sciences) for the donation of the electrochemical cell, and to the Brazilian Nanotechnology National Laboratory (LNNano) at the Brazilian Center of Research in Energy and Materials (CNPEM) for the XRD facilit
    corecore