145 research outputs found
Stiffened panels damage tolerance determination using an optimization procedure based on a linear delamination growth approach
The damage tolerance of delaminated composite panels under compressive load is usually numerically evaluated by means of computationally expensive non-linear approaches. In this study, an alternative numerical linear approach, able to mimic the delamination propagation initiation, is proposed. With the aim to exploit its benefits, in terms of computational costs reduction, the proposed linear methodology has been used in this study in conjunction with an optimization analysis to assess the damage tolerance of stiffened composite panels with an impact induced delamination under compression. Indeed, the optimization was aimed to find the minimum delamination growth initiation load for a delaminated stiffened panel with variable delamination size and position, providing indications on the damage tolerance capability of the stiffened panel with an arbitrary positioned and sized delamination induced (as an example) by a low energy impact
Hallux rigidus: current concepts review and treatment algorithm with special focus on interposition arthroplasty
Hallux rigidus represents a surgical challenge, with a multitude of possible surgical options, but with no ideal procedures. The propose of this paper was to review the actual knowledge on the operative techniques, paying particular attention to the evolution of interposition arthroplasties, as an alternative to arthrodesis and prosthesis in the advanced stages of the disease
Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation
The neonicotinoid Clothianidin has a negative impact on NF-\u3baB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees
Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation
The neonicotinoid Clothianidin has a negative impact on NF-ÎşB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees
Bipolar Patients and Bullous Pemphigoid after Risperidone Long-Acting Injectable: A Case Report and a Review of the Literature
Neuropsychiatric disorders are found to be associated with bullous pemphigoid (BP), an autoimmune subepidermal blistering disease. Antipsychotics have emerged as possible inducing factors of BP. However, large sample studies concerning BP associated with antipsychotics, as well as with specific mental disorders, are still lacking. Our review retrieved a few clinical studies and case reports on the topic, producing controversial results. We report for the first time a bipolar patient case presenting BP following five-month therapy with risperidone long-acting injectable (LAI). We hypothesize that the dermatological event is associated with the medication administered. The issue emerged during psychiatric consultation and was confirmed by histological examination, direct and indirect immunofluorescence studies, plus positive plasma and cutaneous BP180 and BP230 IgG. Neurodegeneration or neuroinflammation might represent a primary process leading to a cross-reactive immune response between neural and cutaneous antigens and contributing to self-tolerance failure. Furthermore, the time sequence of the shared biological mechanisms leading to clinical manifestations of the neuropsychiatric disorder and BP remains undefined. BP comorbid with bipolar disorder might occasionally represent a serious health risk and affect patients’ physical and psychosocial quality of life. Thus, clinicians treating psychiatric patients should consider BP as a possible adverse effect of psychotropic medications
Diagnosis and Treatment of Pulmonary Disease in Sea Turtles (Caretta caretta)
The aim of this study was to describe the clinical signs, radiographic, endoscopic and CT
findings, cytological and microbiological findings and treatments of pulmonary diseases in sea turtles,
in order to obtain an accurate diagnosis that avoids unnecessary therapy and antibiotic-resistance
phenomena. In total, 14 loggerheads (Caretta caretta), with clinical and/or radiographic findings
of pulmonary pathology, were assessed through various combinations of clinical, radiological,
CT, endoscopic examination and bronchoalveolar lavage, which recovered fluid for cytologic and
microbiologic analysis. In all cases, radiographic examination led to a diagnosis of pulmonary
disorders—4 unilateral and 10 bilateral. All bacteria cultured were identified as Gram-negative.
Antibiotic resistance was greater than 70% for all beta-lactams tested. In addition, all bacterial
strains were 100% resistant to colistin sulfate and tetracycline. Specific antibiotic therapies were
formulated for seven sea turtles using Enrofloxacin, and for four sea turtles using ceftazidime. In two
turtles, antibiotic therapy was not included due to the presence of antibiotic resistance against all the
antibiotics evaluated. In both cases, the coupage technique and environmental management allowed
the resolution of the lung disease without antibiotics. All 14 sea turtles were released back into the
sea. Radiographic examination must be considered the gold standard for screening sea turtles that
show respiratory signs or abnormal buoyancy. Susceptibility testing with antimicrobials allowed
appropriate therapy, including the reduction of antibiotic-resistance
Wing structure of the next-generation civil tiltrotor: From concept to preliminary design
The main objective of this paper is to describe a methodology to be applied in the preliminary design of a tiltrotor wing based on previously developed conceptual design methods. The reference vehicle is the Next-Generation Civil Tiltrotor Technology Demonstrator (NGCTR-TD) developed by Leonardo Helicopters within the Clean Sky research program framework. In a previous work by the authors, based on the specific requirements (i.e., dynamics, strength, buckling, functional), the first iteration of design was aimed at finding a wing structure with a minimized structural weight but at the same time strong and stiff enough to comply with sizing loads and aeroelastic stability in the flight envelope. Now, the outcome from the first design loop is used to build a global Finite Element Model (FEM), to be used for a multi-objective optimization performed by using a commercial software environment. In other words, the design strategy, aimed at finding a first optimal solution in terms of the thickness of composite components, is based on a two-level optimization. The first-level optimization is performed with engineering models (non-FEA-based), and the second-level optimization, discussed in this paper, within an FEA environment. The latter is shown to provide satisfactory results in terms of overall wing weight, and a zonal optimization of the composite parts, which is the starting point of an engineered model and a detailed FEM (beyond the scope of the present work), which will also take into account manufacturing, assembly, installation, accessibility and maintenance constraints
- …