analytical stiffness matrix for curved metal wires

Abstract The paper presents an analytic stiffness matrix for curved thin metal wires, derived by the application of the second Castigliano's Theorem. The matrix accounts both bending and axial stiffness contributions in plane. The beam geometry is described by a cubic polynomial function of the curvature radius with a monotonical attitude angle as the independent variable. The solution proposed if fully analytical although a consistent number of adding factors appear. Some test cases are discussed and compared with Finite Element solutions, formed by a plentiful assembly of straight beams

Oral Lactoferrin in HIV-1 Vertically Infected Children: An Observational Follow-up of Plasma Viral Load and Immune Parameters

Lactoferrin (LF) is a mammalian iron-binding glycoprotein with antiviral effects. This preliminary study evaluated 6 months' LF (3 g/day, orally) treatment in 22 human immunodeficiency virus type 1 (HIV-1) vertically infected children. Plasma viral load and CD4+ cell counts were assessed every 3 months; before, during and after LF administration. No significant changes were observed during the pre-treatment period. By 6 months, mean (± SD) plasma viral load (log10) declined from 4.54 (± 0.65) to 4.28 (± 0.60); median percentage CD4+ cell count increased from 21.5% to 24.5%. Two months after treatment discontinuation, mean plasma viral load did not differ significantly from baseline or month 6 levels, but the percentage CD4+ cell count remained significantly higher than the baseline value. LF plus antiretroviral (ARV) therapy was more effective at increasing CD4+ cell count than LF alone. None of the patients showed any new HIV-1-related symptoms at follow-up. LF might be a useful addition to ARV therapy, ..

SFM-MVS photogrammetry for rockfall analysis and hazard assessment along the ancient roman via Flaminia road at the Furlo gorge (Italy)

Rockfall events represent significant hazards for areas characterized by high and steep slopes and therefore effective mitigation controls are essential to control their effect. There are a lot of examples all over the world of anthropic areas at risk because of their proximity to a rock slope. A rockfall runout analysis is a typical 3D problem, but for many years, because of the lack of specific software, powerful computers, and economic reasons, a 2D approach was normally adopted. However, in recent years the use of 3D software has become quite widespread and different runout working approaches have been developed. The contribution and potential use of photogrammetry in this context is undoubtedly great. This paper describes the application of a 3D hybrid working approach, which considers the integrated use of traditional geological methods, Terrestrial Laser Scanning, and drone based Digital Photogrammetry. Such approach was undertaken in order to perform the study of rockfall runout and geological hazard in a natural slope in Italy in correspondence of an archaeological area. Results show the rockfall hazard in the study area and highlights the importance of using photogrammetry for the correct and complete geometrical reconstruction of slope, joints, and block geometries, which is essential for the analysis and design of proper remediation measures

An RBF Meshless Approach to Evaluate Strain Due to Large Displacements in Flexible Printed Circuit Boards

Thin plates are very often employed in a context of large displacements and rotations, for example, whenever the extreme flexibility of a body can replace the use of complicated kinematic pairs. This is the case of the flexible Printed Circuit Boards (PCBs) used, for example, within last-generation foldable laptops and consumer electronics products. In these applications, the range of motion is generally known in advance, and a simple strategy of stress assessment leaving out nonlinear numerical calculations appears feasible other than desirable. In this paper, Radial Basis Functions (RBFs) are used to represent a generic transformation of a bi-dimensional plate, with all the derivate fields being analytically achieved without the need for a numerical grid for large-displacement applications. Strains due to bending are easily retrieved with this method and satisfactorily compared to analytical and shell-based Finite Element Method (FEM) benchmarks. On the other hand, the computational costs of the juxtaposed methods appear far different; with the machine being equal, the orders of magnitude of the time elapsed in computation are seconds for the RBF-based strategy versus minutes for the FEM approach

Molecular analysis of a sunflower gene encoding an homologous of the B subunit of a CAAT binding factor

A genomic DNA fragment containing the complete LEAFY COTYLEDON1-LIKE (HaL1L) gene was retrieved by chromosome walking. Its sequence was confirmed and elongated by screening a sunflower genomic DNA BAC Library. HaL1L, whose cDNA had already been sequenced and characterized, encodes a NF-YB subunit of a CCAAT box-binding factor (NF-Y) involved in the early stages of zygotic and somatic embryogenesis in the Helianthus genus. In the HaL1L 50-flanking region, elements specific to a putative TATA-box promoter and two ‘‘CG isles’’ were identified. An investigation of the methylation status of these CG rich DNA regions showed that differentially methylated cytosines were recognizable in the DNA of embryos on the fifth day after pollination in comparison to leaf DNA suggesting that during plant development epigenetic regulation of HaL1L transcription was achieved by methylating cytosine residues. We also searched the HaL1L nucleotide sequence for cis-regulatory elements able to interact with other transcription factors (TFs) involved in the HaL1L regulation. Of the elements identified, one of the most intriguing is WUSATA, the target sequence for the WUSCHEL (WUS) TF, which may be part of a complex regulation network controlling embryo development. In this article, we show that the WUSATA target site, located in the intron of HaL1L, is able to bind the TF WUS. Interestingly, we found auxin and abscisic acid responsive motifs in the HaL1L promoter region suggesting that this gene may additionally by under hormonal control. Finally, the presence of a cytoplasmic polyadenylation signal downstream to the coding region indicates that this gene may also be controlled at the translation level by a temporarily making the pre-synthesized HaL1L mRNA unavailable for protein synthesis

Effects of warm-up before stretching on flexibility and torque development in elderly

The purpose of the study was to analyze the effect of warm up exercises on flexibility and torque development of elderly subjects submitted to a protocol of hamstring muscles stretching. 28 subjects (9 men and 19 women), aged 66.4±6 years, volunteered for this study. Subjects were randomly divided into 2 protocols: a stretching protocol (group A) and a warm up and stretching protocol (group B). Both groups received the intervention for 4 weeks, with three sessions per week, consisting of 6 bouts of active stretching lasting 30 seconds. Subjects were evaluated on selection (T1), immediately before the intervention (T2), immediately after (T3) and a month after (T4) the intervention period for measures of knee extension range of motion (ROM) and angle with a goniometer and for active and passive peak torque (Nm s-1) at 60°/s and 2°/s respectively using a isokinetic dynamometer. Anova Two-Way and a post hoc analysis using the Tukey’s test were applied to test the differences between and within groups. Both groups presented reduction of the knee extension range of motion deficit (p=0.001), increase of the active peak torque flexor in eccentric (p=0.003) and concentric (p=0.015) phases, and reduction of the peak torque angle of the knee flexors in the eccentric phase (p=0.046) when comparing T3 with T2 for both groups, without significant difference between groups. The passive peak torque did not vary significantly (p\u3e0.05) between the evaluations. The pre-exercise warm up was unable to elicit differences in flexibility and torque development of the hamstrings in elderly subjects

Omalizumab treatment in Samter's triad: case series and review of the literature

OBJECTIVE: Samter’s triad is the combination of asthma, aspirin sensitization, and nasal polyposis. Few data are available on the use of omalizumab in this disease. The study aimed to describe the impact of omalizumab on clinical and functional parameters and the quality of life of a series of patients with Samter’s triad. Moreover, we aimed to provide a review of the literature on this topic. PATIENTS AND METHODS: We retrospectively described four patients with Samter’s triad undergoing omalizumab therapy. Clinical, functional, and immunological data of these patients were collected at baseline and follow-up. RESULTS: Reduction of asthma exacerbations and salbutamol rescue therapy were observed in all patients after anti-IgE treatment together with an improvement in the quality of life. A significant improvement in FEV1, FVC, and FEF25-75 was observed. No major side-effects were observed. A total of 14 studies regarding omalizumab in aspirin-exacerbated respiratory diseases were included in the review, comprising 78 patients. All studies reported a good efficacy in improving asthma control; restoration of aspirin tolerance was repeatedly reported. CONCLUSIONS: The results of our case series and review of the literature suggest that omalizumab effectively improves asthma control, lung function tests, and quality of life in patients with Samter’s triad

High fidelity numerical fracture mechanics assisted by RBF mesh morphing

The study and design of cyclically loaded structures cannot neglect the evaluation of their fatigue behavior. Today numerical prediction tools allow adopting, in various industrial fields, refined and consolidated procedures for the assessment of cracked parts through analyses based on fracture mechanics. An high level of detail can be obtained through the use of well consolidated FEM methods, allowing an accurate and reliable calculation of the flaw Stress Intensity Factor (SIF) and its resulting prediction in terms of crack propagation. A challenging step for this computational workflow remains, however, the generation and update of the computational grid during crack evolution. It is in this context that radial basis functions (RBF) mesh morphing is emerging as a viable solution to replace the complex and time-consuming remeshing operation. The flaw front is updated, according to its propagation, by automatically deforming the numerical grid obtaining an evolutionary workflow suitable to be used for industrially-sized numerical meshes (many millions of nodes). A review of applications, obtained by exploiting FEA (Ansys Mechanical) and mesh morphing (RBF Morph) state of-the-art tools, is presented in this work. At first the proposed workflow is applied on a circular notched bar with a defect controlled by a two-parameters evolution. The same approach is then refined and demonstrated for a Multi Degree of Freedom (MDoF) case on the same geometry and on the vacuum vessel port stub from the fusion nuclear reactor Iter