Hellenic Air Force

About: Hellenic Air Force is a government organization based out in Athens, Greece. It is known for research contribution in the topics: Denosumab & Osteoporosis. The organization has 304 authors who have published 434 publications receiving 8644 citations. The organization is also known as: Greek Air Force & HAF.

Using reliability indicators to explore human factors issues in maintenance databases

Abstract: Purpose – The aim of this paper is to explore the usefulness of repairable parts simple historical databases in assisting the human factors experts to identify candidate areas for applying human factors methods. Therefore, also contributing to the search for maintenance quality improvement. Design/methodology/approach – The study was based on the failure history of part fleets installed on the same type of jet engines, and used mean time between failures (MTBF) and failure rates plots, the Laplace trend test, the AMSAA‐Crow‐Duane model and serial correlations. Findings – Increasing and decreasing trends in failure rates indicated factors that cause deflection from the literature assumptions of constant failure mode and “as good as new” maintenance philosophy. Further statistical calculations revealed patterns between MTBF and frequency of maintenance, specific serial numbers (SN) vulnerability to replacement and depot maintenance tasks, correlations between MTBF and number of both installations and maintenances, and influence of the maintenance month on the maintenance‐failure hours' interval. Practical implications – The literature refers to the relation between the parts reliability and the human factors in the maintenance domain. The research confirmed the literature references in data collection problems coming from human factors interferences; the patterns found were attributed to system deficiencies related to workload management, parts configuration management, supervision and manufacturing problems. Originality/value – The application of this research in combination with methods such as field observations and interviews of personnel involved in the maintenance domain can uncover specific maintenance working environment weaknesses and lead to suitable remedies.

Performance of clear vacuum-formed thermoplastic retainers depending on retention protocol: a systematic review

Abstract: We aimed at comparing the performance of vacuum-formed thermoplastic retainers (VFR) worn either full-time or part-time, in maintaining orthodontic treatment results in terms of tooth alignment, arch form and occlusion. We reviewed randomized and prospective controlled clinical trials comparing VFR wearing protocols and searched databases, without restrictions, for published and unpublished literature. The risk of bias was assessed using the Cochrane Risk of Bias tool and the overall level of certainty in the evidence following ADA methodology. 184 studies were initially identified and reduced to the 3 randomized controlled trials included in the systematic review by means of specific criteria. One study followed patients 1 year into retention, and the other two for 6 months. Little's Irregularity Index, intermolar and intercanine width, arch length, overjet and PAR score did not differ significantly between the patients wearing their retainers part time or full time. We observed a slight increase in the overbite in the part-time group in only one trial. With a moderate level of certainty, we found that during the observation period, full-time VFR wear is not superior to part-time, bearing in mind the potential implications for health burden, retainer longevity and cost-effectiveness, as well as patient satisfaction and compliance.

Papillary thyroid microcarcinoma presenting as lymph node metastasis--a diagnostic challenge: case report and systematic review of literature.

Abstract: Papillary thyroid microcarcinomas (PTMCs) have an excellent prognosis, although a few may metastasize to cervical lymph nodes. However, an infiltrated palpable neck node without evidence of thyroid disease at presentation is uncommon. We report a patient with PTMC presenting as a solitary lymph node metastasis without evidence of primary thyroid tumor in thyroid imaging and with inconclusive lymph node fine-needle biopsy (FNB) cytology. In our case, node excision and histological examination set the diagnosis and immunocytochemical staining of the FNB specimens verified it. A systematic review of reported similar cases was performed; relevant diagnostic dilemmas were also summarized. The clinical presentation of this type of papillary carcinoma becomes evident at a relatively younger age and affects almost equally the two genders; the enlarged lymph node is almost exclusively ipsilateral to the primary tumor, which may be unifocal or multifocal and is difficult to detect by thyroid imaging modalities. Lymph node FNB cytology, thyroglobulin (Tg) measurement in the washout liquid of the FNB needle, FNB immunocytochemistry and lymph node excision accompanied by histological examination provide a stepwise diagnostic approach. We conclude that PTMC may present as a lymph node metastasis without evidence of a primary thyroid tumor. In such cases, thyroid malignancy should be suspected and, in the presence of negative or non-diagnostic lymph node FNB cytology, measurement of Tg in the fluid aspirate should be performed.

Lymphomatoid papulosis type D in a fingolimod-treated multiple sclerosis patient.

Abstract: 1630 http://msj.sagepub.com Experimental mouse models have shown that fingolimod blocks CD4+ T-cell immunosurveillance of myeloma and B-cell lymphoma and in consequence leads to cancer development.4 While the development of basal cell carcinoma of the upper lip in our patient could be attributed to fingolimod, the antecedent history of basal cell carcinoma in October 2011, before the medication was started, makes the correlation in our patient less credible.