131 research outputs found

    A Design Heritage-Based Forecasting Methodology for Risk Informed Management of Advanced Systems

    Get PDF
    The development of next generation systems often carries with it the promise of improved performance, greater reliability, and reduced operational costs. These expectations arise from the use of novel designs, new materials, advanced integration and production technologies intended for functionality replacing the previous generation. However, the novelty of these nascent technologies is accompanied by lack of operational experience and, in many cases, no actual testing as well. Therefore some of the enthusiasm surrounding most new technologies may be due to inflated aspirations from lack of knowledge rather than actual future expectations. This paper proposes a design heritage approach for improved reliability forecasting of advanced system components. The basis of the design heritage approach is to relate advanced system components to similar designs currently in operation. The demonstrated performance of these components could then be used to forecast the expected performance and reliability of comparable advanced technology components. In this approach the greater the divergence of the advanced component designs from the current systems the higher the uncertainty that accompanies the associated failure estimates. Designers of advanced systems are faced with many difficult decisions. One of the most common and more difficult types of these decisions are those related to the choice between design alternatives. In the past decision-makers have found these decisions to be extremely difficult to make because they often involve the trade-off between a known performing fielded design and a promising paper design. When it comes to expected reliability performance the paper design always looks better because it is on paper and it addresses all the know failure modes of the fielded design. On the other hand there is a long, and sometimes very difficult road, between the promise of a paper design and its fulfillment; with the possibility that sometimes the reliability promise is not fulfilled at all. Decision makers in advanced technology areas have always known to discount the performance claims of a design to a degree in proportion to its stage of development, and at times have preferred the more mature design over the one of lesser maturity even with the latter promising substantially better performance once fielded. As with the broader measures of performance this has also been true for projected reliability performance. Paper estimates of potential advances in design reliability are to a degree uncertain in proportion to the maturity of the features being proposed to secure those advances. This is especially true when performance-enhancing features in other areas are also planned to be part of the development program

    Adverse events following covid-19 vaccine in patients previously injected with facial filler: Scoping review and case report

    Get PDF
    The \u201cVaccines and Related Biological Products Advisory Committee 17 December 2020 Meeting Briefing Document\u201d, formulated by the FDA, reported three cases of swelling in areas previously injected with HA filler, introducing the possible relationship between a COVID-19 vaccine and adverse events in areas previously injected with HA fillers. The aim of this research is to report a case of an adverse event following a COVID-19 vaccine in a patient previously injected with facial filler. Furthermore, a scoping review on the same topic was performed. The research was carried out on the electronic databases PubMed, Cochrane Library, Web of Science, Google Scholar and Scopus. The selection process identified four articles as eligible for inclusion in the review. Nineteen patients, including the described case report, who experienced an adverse event following a COVID-19 vaccine in areas previously injected with facial filler were identified. Adverse events following a COVID-19 vaccine in patients previously injected with facial filler appear to be rare. A high BDDE cross-linking rate and/or a low-molecular-weight hyaluronic acid filler may have a higher tardive adverse event rate when triggered

    Potential human and plant pathogenic species in airborne pm10 samples and relationships with chemical components and meteorological parameters

    Get PDF
    A preliminary local database of potential (opportunistic) airborne human and plant pathogenic and non-pathogenic species detected in PM10 samples collected in winter and spring is provided, in addition to their seasonal dependence and relationships with meteorological parameters and PM10 chemical species. The PM10 samples, collected at a Central Mediterranean coastal site, were analyzed by the 16S rRNA gene metabarcoding approach, and Spearman correlation coefficients and redundancy discriminant analysis tri-plots were used to investigate the main relationships. The screening of 1187 detected species allowed for the detection of 76 and 27 potential (opportunistic) human and plant pathogens, respectively. The bacterial structure of both pathogenic and non-pathogenic species varied from winter to spring and, consequently, the inter-species relationships among potential human pathogens, plant pathogens, and non-pathogenic species varied from winter to spring. Few non-pathogenic species and even fewer potential human pathogens were significantly correlated with meteorological parameters, according to the Spearman correlation coefficients. Conversely, several potential plant pathogens were strongly and positively correlated with temperature and wind speed and direction both in winter and in spring. The number of strong relationships between presumptive (human and plant) pathogens and non-pathogens, and meteorological parameters slightly increased from winter to spring. The sample chemical composition also varied from winter to spring. Some potential human and plant pathogens were correlated with chemicals mainly associated with marine aerosol and/or with soil dust, likely because terrestrial and aquatic environments were the main habitats of the detected bacterial species. The carrier role on the species seasonal variability was also investigated

    Clinical experience with pegylated hyaluronic acid fillers: A 3-year retrospective study

    Get PDF
    BACKGROUND: Hyaluronic acid fillers are the most used worldwide, thanks to the high biocompatibility and safety profile of HA and it is also the only substance that can be \u201cdissolved\u201d due to the hyaluronidase effect. AIM: A retrospective clinical evaluation of the outcomes following PEG cross-linked HA-based filler injection was performed. METHODS: Data were collected from December 2017 to June 2020. A total of 65 patients (12 M, 53 F), age ranging 28\u201362 year\u2019s old (mean age 42.3), were treated. Exclusion criteria were applied and in accord to treatment plan, were used specific site injections and fillers. Follow-up was evaluated between 6 months and 2 years. RESULTS: A total of 61 treatments using 124 vials of HA filler crosslinked with PEG were performed. CONCLUSION: In conclusion, from 2014, HA fillers having PEG as cross-linker agent have been introduced in the european market. Several papers have been published in order to evaluate the features of these fillers, although, to the best of our knowledge, this is the first clinical paper regarding their use

    Botulinum toxin type a reconstituted with lidocaine: A report of 1000 consecutive cases

    Get PDF
    (1) Background: There is an increasing demand for a reversal of the aging process and, nowadays, more patients are seeking minimally invasive methods instead of surgery to meet this goal. The purpose of this paper is to evaluate the predictability of the off-label aesthetic use of botulinum toxin type A (BoNTA) reconstituted with lidocaine. (2) Methods: One thousand treatments, between January 2010 and January 2020, with BoNTA reconstituted with lidocaine for the rejuvenation of the upper third of the face, were performed and retrospectively evaluated. (3) Results: A few seconds after the BoNTA injections, the effect of muscle paralysis was seen in all cases; this allowed providing an optimal symmetric result with no need for a touch-up procedure at the control after three weeks. A burning sensation during the injections was claimed by almost all patients. Major complications were not registered. No touch-up procedures were required. (4) Conclusions: The results of this study show how the reconstitution of BoNTA with lidocaine may avoid imperfect results after the injections; the immediate feedback on the extent of paralysis to be expected from the chemodenervation action of BoNTA allows the physician to have immediate control of the final result

    Hydroadenocarcinoma, a rare tumor to be kept in mind

    Get PDF
    Background: Nowadays, the incidence of skin cancer has increased, especially in the elderly population, probably due to increasing longevity and lifestyle changes. Sun exposure plays a pivotal role in the development of the skin tumors, among these basal cell carcinoma (BCC) is the most frequent with an incidence 4 times higher than that of squamous cell carcinoma (SCC) and it is 20 times more common than melanoma. On the other hand, skin adnexal tumors are extremely rare and hydroadenocarcinoma (HC) is generally considered a malignancy of eccrine cutaneous sweat glands. It occurs in 0.01% of skin cancers and often it can mimic other skin cancers, particulary BCC. Case presentation: An 84-year-old woman come to our attention for a neoformation on the upper lip. Seeing as she had previously undergone operations for removal of basaliomas on the face, the lesion was believed to be a recurrence. Facial and neck MRI and CT-scan analysis revealed that the lesion appeared in correspondence of the midline and paramedian site of the upper lip with extension into the left nasal cavity, not dissociable from the surrounding tissues. For this reason, the patient underwent an \u201cen bloc\u201d resection instead of Mohs' surgery. The definitive histological diagnosis concluded that the lesion was a hydroadenocarcinoma. Conclusion: In front of a nodular lesion of the skin it is always advisable to perform a biopsy to type the neoformation and also exclude rare tumors such us hydroadenocarcinoma

    Is the treatment of the tear trough deformity with hyaluronic acid injections a safe procedure? A systematic review

    Get PDF
    Among the various therapeutic options for the treatment of tear trough deformities, the use of hyaluronic acid-based fillers has constantly been increasing. The aim of this research is to conduct a systematic review of the published literature related to the use of hyaluronic acid-based dermal fillers for the treatment of tear trough deformities and possible related complications. A search of the published literature was conducted following the PRISMA guidelines, including PubMed, Cochrane Library, and Ovid databases. Text words and Medical Search Headings (MeSH terms) were used to identify nine articles included in our analysis. The most used filler was Restylane (Galderma). The injection technique was performed through the use of a cannula or, more frequently, with a needle, through the execution of boluses or retrograde release. The injection plane was predominantly the supra-periosteal layer. The most observed side effects were mild and included redness, edema, contour irregularities, bruising, and blue-gray dyschromia. The degree of patient satisfaction was high, with an optimal aesthetic result that was maintained for 6 to 12 months. Although the duration of treatment of tear trough deformities with HA fillers is not comparable to surgical treatment, this is a minimally invasive, safe procedure, quick to perform, and with a high degree of patient satisfaction

    Facial artery myomucosal flap vs. Islanded facial artery myomucosal flap viability: A systematic review

    Get PDF
    The aim of this study was to estimate the overall viability of the islanded facial artery myomucosal flap (iFAMM) compared to the facial artery myomucosal flap (FAMM). A systematic review of English articles was performed on PubMed and Cochrane Library electronic databases. Search terms included every nomenclature variant for FAMM flap and iFAMM flap. A total of 373 articles were identified, and 20 articles were considered eligible for inclusion in the review. A total of 486 flaps were evaluated (350 FAMM and 136 i-FAMM flaps). In all studies, the primary outcome assessed was flap viability, collecting the rate of total and partial flap necrosis and then comparing FAMM to i-FAMM. Overall reported partial/total necrosis rate for FAMM flap was 9.7%, 1.4% as total and 8.3% as partial necrosis. Overall partial/total reported necrosis rate for iFAMM flaps was 2.2%, 1.5% as total and 0.7% as partial necrosis. FAMM flaps, both as classical or islanded variants, are an effective option for intraoral small/medium sized defect reconstruction. Outcomes from the present review show a higher partial/total survival rate when this flap is harvested as islanded flap

    Health related quality of life outcomes in HIV-Infected patients starting different combination regimens in a randomised multinational trial: the INITIO-QoL Substudy

    Get PDF
    The health-related quality of life (HRQoL) outcomes in HIV-infected, treatment-naive patients starting different HAART regimens in a 3-year, randomized, multinational trial were compared. HRQoL was measured in a subgroup of patients enrolled in the INITIO study (153/911), using a modified version of the MOS-HIV questionnaire. The regimens compared in the INITIO trial were composed by two NRTIs (didanosine + stavudine) plus either an NNRTI (efavirenz) or a PI (nelfinavir), or both (efavirenz + nelfinavir). Primary HRQoL outcomes were Physical and Mental Health Summary scores (PHS and MHS, respectively). During follow-up, an increase of PHS score was observed in all treatment arms. The MHS score remained substantially unchanged with the four-drug combination and showed with both NNRTI- and PI-based three-drug regimens a marked trend toward improvement, which became statistically significant when a multiple imputation method was used to adjust for missing data. Overall, starting all the combination regimens compared in the INITIO study was associated with a maintained or slightly improved HRQOL status, consistently with the positive immunological and virological changes observed in the main study. The observed differences in the MHS indicate a possible HRQoL benefit associated to the use of three-drug, two-class regimens and no additional benefit for the use of four-drug, three-class regimens, confirming that three-drug, two-class regimens that include two NRTIs plus either an NNRTI or a PI should be preferred as initial treatment of HIV infection
    corecore