698 research outputs found

    GPS Seismology for a moderate magnitude earthquake: Lessons learned from the analysis of the 31 October 2013 ML6.4 Ruisui (Taiwan) earthquake

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    The 31 October 2013 ML 6.4 Ruisui earthquake was well recorded by twelve 50-Hz, four 20-Hz and thirteen 1-Hz GPS receivers, and twenty-five strong motion stations located within the epicentral distance of 90 km in eastern Taiwan. Kinematic positioning solutions estimated by four GNSS software (TRACK, RTKLIB, GIPSY, VADASE) are used to derive the seismic waveforms and the co-seismic displacements for this event; strong motion accelerometers are used to verify the capability of high rate GPS to detect seismic waves generated by this earthquake. Results show that the coordinate repeatability of the GPS displacements time series are ~6 mm and ~20 mm standard deviation in the horizontal and vertical components respectively, after applying spatial filtering. The largest co-seismic displacement derived from high-rate GPS is nearly 15 centimeter at 5 km northeast of the epicenter. S waves and surface waves are successfully detected by motions of high-rate GPS and double-integrated accelerometers within the 15 km epicentral distance. For the first time twelve 50-Hz and four 20 Hz GPS observations for seismological study were used and analyzed in Taiwan; a clear benefit was evidenced with regard to the seismic waves features detection, with respect to the 1-Hz GPS data, so that ultra-high rate (> 1-Hz) observations can compensate the sparse coverage of seismic data, provided proper monuments for the GPS permanent stations are realized. Spectra analysis between co-located GPS and strong motion data further suggests that the optimal sampling rate for high-rate GPS Seismology study is 5 Hz. The 2013 Ruisui Taiwan earthquake recorded by the high-rate GPS permanent stations network in Taiwan demonstrates the benefits of GPS Seismology for a moderate size earthquake at a local scale

    Gallbladder polyps in association with metachromatic leukodystrophy

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    Polypoid lesions of the gallbladder (PLG) are rare in the paediatric population. Growth in technology with the availability of high-quality ultrasonography and in the experience of radiologists in detecting such lesions, has led to an increase in incidental detection of PLG. In children, the occur either as a primary disorder or in association with other conditions, including metachromatic leukodystrophy, Peutz- Jeghers syndrome, or pancreatobiliary malunion [1]. Due the rarity of these lesions in the paediatric age group, accurate management algorithms are inherited from the adult population. In these, PLG is a more common pathology, occurring in 4\u20137% of patients undergoing ultrasonography, with clinical significance relating largely to their malignant potential [2,3]

    Motion artefacts in cone beam CT: an in vitro study about the effects on the images

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    OBJECTIVE: In cone beam CT (CBCT), imperfect patient immobility, caused by involuntary movements, is one of the most important causes of artefacts and image quality degradation. Various works in literature address this topic, but seldom is the nature of the movement correlated with the type of artefact and the image degradation in a systematic manner, and the correlation analyzed and explained. METHODS: All three types of movements that can occur during a scan—nodding, tilting and rolling—were applied to a dry skull, in various manners from abrupt to gradual through the entire scan, at different times and angles, over a wide range of displacements. 84 scans were performed, with different skull movements, and the resulting images examined by two skilled radiologists, rated in a four-point scale and statistically analyzed. A commercial CBCT machine was used, featuring supine patient positioning. RESULTS: Different types of movements induce different artefacts, in different parts of the anatomy. In general, movement of short duration may lead to double contours (bilateral or monolateral depending upon the angle of the scan at which they occur), whereas gradual movements result into blurring. CONCLUSION: Not all movements cause motion artefacts that equally jeopardize the image. Rolling is the type of movement that most severely affects the image diagnostic value. ADVANCES IN KNOWLEDGE: These findings may help practitioners to identify the causes of motion artefacts and the resulting image degradation, and remediate them, and manufacturers to improve the patient-positioning devices

    Mg-based materials diminish tumor spreading and cancer metastases

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    Cancer metastases are the most common causes of cancer-related deaths. The formation of secondary tumors at different sites in the human body can impair multiple organ function and dramatically decrease the survival of the patients. In this stage, it is difficulty to treat tumor growth and spreading due to arising therapy resistances. Therefore, it is important to prevent cancer metastases and to increase subsequent cancer therapy success. Cancer metastases are conventionally treated with radiation or chemotherapy. However, these treatments elicit lots of side effects, wherefore novel local treatment approaches are currently discussed. Recent studies already showed anticancer activity of specially designed degradable magnesium (Mg) alloys by reducing the cancer cell proliferation. In this work, we investigated the impact of these Mg-based materials on different steps of the metastatic cascade including cancer cell migration, invasion, and cancer-induced angiogenesis. Both, Mg and Mg-6Ag reduced cell migration and invasion of osteosarcoma cells in coculture with fibroblasts. Furthermore, the Mgbased materials used in this study diminished the cancer-induced angiogenesis. Endothelial cells incubated with conditioned media obtained from these Mg and Mg-6Ag showed a reduced cell layer permeability, a reduced proliferation and inhibited cell migration. The tube formation as a last step of angiogenesis was stimulated with the presence of Mg under normoxia and diminished under hypoxia

    Enhancement of the Biological and Mechanical Performances of Sintered Hydroxyapatite by Multiple Ions Doping

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    In the present work, hydroxyapatite (HA) nanoparticles doped with Mg2+, Sr2+, and Zn2+ ions are developed by wet neutralization method and then sintered at 1,250°C to obtain bulk consolidated materials. Physicochemical and microstructural analyses show that the presence of doping ions in the HA structure induced the formation of βTCP as secondary phase, during the sintering process, and we found that this effect is depending on the stability of the various doping ions in the hydroxyapatite lattice itself. We also found that the formation of βTCP as secondary phase, in turn, confines the grain growth of HA induced by the high-temperature sintering process, thus leading to a strong increase of the flexural strength of the bulk materials, according to Hall-Petch-like law. Furthermore, we found that the doping ions enter also in the structure of the βTCP phase; besides the grain growth confinement, also the solubility and ion release ability of the final materials were enhanced. In addition to ameliorate the mechanical performance, the described phenomena also activate multiple biofunctionalities: (i) ability to upregulate various genes involved in the osteogenesis, as obtained by human adipose stem cells culture and evaluated by array technology; (ii) enhanced resistance to the adhesion and proliferation of Gram+ and Gram– bacterial strains. Hence, our results open a perspective for the use of sintered multiple ion-doped HA to develop ceramic biodevices, such as plates, screws, or other osteosynthesis media, with enhanced strength, osteointegrability, and the ability to prevent post-surgical infections

    Predictive Factors of Surgical Site Infection in Prosthetic Joint Surgery: A Prospective Study on 760 Arthroplasties

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    Purpose. The success of total joint arthroplasty (TJA) has led to consistent growth in the use of arthroplasty in progressivelyyounger patients. However, more than 10 percent of patients require revision surgery due to implant failure caused by asepticor septic inflammation. Among the latter, surgical site infection (SSI) represents one of the worst complications of TJA,potentially resulting in the removal of the prosthesis. The aim of our study was to identify potential risk factors for SSIs in apopulation of patients undergoing TJA. Methods. TJA were prospectively recruited at Casa di Cura Santa Maria Maddalenafrom February 2019 to April 2020. Age, sex, major comorbidities, American Society of Anesthesiologists (ASA) class, length ofsurgery, type of surgical suture, total hospital length of stay, and clinical laboratory data were collected. The study populationwas then divided into two groups: Group A, normal postoperative course, and Group B, patients who developed SSI at follow-up (17-25 days). Results. 25/760 (3.3%) patients developed SSIs at follow-up. Clinical and demographic parameters were notdifferent between the two groups. Total leucocyte and neutrophil values at discharge resulted to be significatively higher inGroup B compared to Group A (p = 0:025 and p = 0:016, respectively). Values of 7860/ÎĽL for total leucocyte and 5185/ÎĽL forneutrophil count at discharge significantly predicted the future development of SSI (AUC 0.623 and AUC 0.641, respectively; p< 0:05) independently from confounding factors (total leukocytes: O:R: = 3, 69 [95% C.I. 1,63-8,32]; neutrophils: O:R: = 3, 98[95% C.I. 1,76-8,97]). Deep SSIs has been diagnosed significantly before superficial SSIs (p = 0,008), with a median advance of9 days. Conclusion. Total leukocytes and neutrophils at discharge seem useful to identify a population at risk for thedevelopment of septic inflammation at the surgical site following TJA. Further studies with larger populations are needed to develop a predictive SSIs risk score that should include those variables

    Stem Cell Fate and Immunomodulation Promote Bone Regeneration via Composite Bio-Oss®/AviteneTM Biomaterial

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    Bone defects in maxillofacial regions lead to noticeable deformity and dysfunctions. Therefore, the use of biomaterials/scaffolds for maxillofacial bone regrowth has been attracting great interest from many surgical specialties and experts. Many approaches have been devised in order to create an optimal bone scaffold capable of achieving desirable degrees of bone integration and osteogenesis. Osteogenesis represents a complex physiological process involving multiple cooperating systems. A tight relationship between the immune and skeletal systems has lately been established using the concept of “osteoimmunology,” since various molecules, particularly those regulating immunological and inflammatory processes, are shared. Inflammatory mediators are now being implicated in bone remodeling, according to new scientific data. In this study, a profiler PCR array was employed to evaluate the expression of cytokines and chemokines in human adipose derived-mesenchymal stem cells (hASCs) cultured on porous hydroxylapatite (HA)/Collagen derived Bio-Oss® /Avitene scaffolds, up to day 21. In hASCs grown on the Bio-Oss® /Avitene biomaterial, 12 differentially expressed genes (DEGs) were found to be up-regulated, together with 12 DEG downregulated. Chemokine CCL2, which affects bone metabolism, tested down-regulated. Interestingly, the Bio-Oss® /Avitene induced the down-regulation of pro-inflammatory interleukin IL-6. In conclusion, our investigation carried out on the Bio-Oss® /Avitene scaffold indicates that it could be successfully employed in maxillofacial surgery. Indeed, this composite material has the advantage of being customized on the basis of the individual patients favoring a novel personalized medicine approach

    Physical activity intervention for elderly patients with reduced physical performance after acute coronary syndrome (HULK study): Rationale and design of a randomized clinical trial

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    Background: Reduced physical performance and impaired mobility are common in elderly patients after acute coronary syndrome (ACS) and they represent independent risk factors for disability, morbidity, hospital readmission and mortality. Regular physical exercise represents a means for improving functional capacity. Nevertheless, its clinical benefit has been less investigated in elderly patients in the early phase after ACS. The HULK trial aims to investigate the clinical benefit of an early, tailored low-cost physical activity intervention in comparison to standard of care in elderly ACS patients with reduced physical performance. Design: HULK is an investigator-initiated, prospective multicenter randomized controlled trial (NCT03021044). After successful management of the ACS acute phase and uneventful first 1 month, elderly (≥70 years) patients showing reduced physical performance are randomized (1:1 ratio) to either standard of care or physical activity intervention. Reduced physical performance is defined as a short physical performance battery (SPPB) score of 4-9. The early, tailored, low-cost physical intervention includes 4 sessions of physical activity with a supervisor and an home-based program of physical exercise. The chosen primary endpoint is the 6-month SPPB value. Secondary endpoints briefly include quality of life, on-treatment platelet reactivity, some laboratory data and clinical adverse events. To demonstrate an increase of at least one SPPB point in the experimental arm, a sample size of 226 patients is needed. Conclusions: The HULK study will test the hypothesis that an early, tailored low-cost physical activity intervention improves physical performance, quality of life, frailty status and outcome in elderly ACS patients with reduced physical performance

    Do Italian women prefer cesarean section? Results from a survey on mode of delivery preferences

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    Background: About 20 million cesareans occur each year in the world and rates have steadily increased in almost all middle- and high-income countries over the last decades. Maternal request is often argued as one of the key forces driving this increase. Italy has the highest cesarean rate of Europe, yet there are no national surveys on the views of Italian women about their preferences on route of delivery. This study aimed to assess Italian women's preference for mode of delivery, as well as reasons and factors associated with this preference, in a nationally representative sample of women.Methods: This cross sectional survey was conducted between December 2010-March 2011. An anonymous structured questionnaire asked participants what was their preferred mode of delivery and explored the reasons for this preference by assessing their agreement to a series of statements. Participants were also asked to what extent their preference was influenced by a series of possible sources. the 1st phase of the study was carried out among readers of a popular Italian women's magazine (Io Donna). in a 2nd phase, the study was complemented by a structured telephone interview.Results: A total of 1000 Italian women participated in the survey and 80% declared they would prefer to deliver vaginally if they could opt. the preference for vaginal delivery was significantly higher among older (84.7%), more educated (87.6%), multiparous women (82.3%) and especially among those without any previous cesareans (94.2%). the main reasons for preferring a vaginal delivery were not wanting to be separated from the baby during the first hours of life, a shorter hospital stay and a faster postpartum recovery. the main reasons for preferring a cesarean were fear of pain, convenience to schedule the delivery and because it was perceived as being less traumatic for the baby. the source which most influenced the preference of these Italian women was their obstetrician, followed by friends or relatives.Conclusion: Four in five Italian women would prefer to deliver vaginally if they could opt. Factors associated with a higher preference for cesarean delivery were youth, nulliparity, lower education and a previous cesarean.Universidade Federal de SĂŁo Paulo, Dept Obstet, SĂŁo Paulo, BrazilWHO, Dept Reprod Hlth & Res, CH-1211 Geneva, SwitzerlandOsservatorio Nazl Salute Donna, ONDa, Milan, ItalyInst Clin Effectiveness & Hlth Policy, Buenos Aires, DF, ArgentinaUniv Florence, Meyer Children Hosp, I-50121 Florence, ItalyUniversidade Federal de SĂŁo Paulo, Dept Obstet, SĂŁo Paulo, BrazilWeb of Scienc
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