185 research outputs found

    Global symplectic coordinates on gradient Kaehler-Ricci solitons

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    A classical result of D. McDuff asserts that a simply-connected complete Kaehler manifold (M,g,ω)(M,g,\omega) with non positive sectional curvature admits global symplectic coordinates through a symplectomorphism Ψ:M→R2n\Psi: M\rightarrow R^{2n} (where nn is the complex dimension of MM), satisfying the following property (proved by E. Ciriza): the image Ψ(T)\Psi (T) of any complex totally geodesic submanifold T⊂MT\subset M through the point pp such that Ψ(p)=0\Psi(p)=0, is a complex linear subspace of Cn≃R2nC^n \simeq R^{2n}. The aim of this paper is to exhibit, for all positive integers nn, examples of nn-dimensional complete Kaehler manifolds with non-negative sectional curvature globally symplectomorphic to R2nR^{2n} through a symplectomorphism satisfying Ciriza's property.Comment: 8 page

    Dynamic surface electromyography using stretchable screen-printed textile electrodes

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    Objective. Wearable devices have created new opportunities in healthcare and sport sciences by unobtrusively monitoring physiological signals. Textile polymer-based electrodes proved to be effective in detecting electrophysiological potentials but suffer mechanical fragility and low stretch resistance. The goal of this research is to develop and validate in dynamic conditions cost-effective and easily manufacturable electrodes characterized by adequate robustness and signal quality. Methods. We here propose an optimized screen printing technique for the fabrication of PEDOT:PSS-based textile electrodes directly into finished stretchable garments for surface electromyography (sEMG) applications. A sensorised stretchable leg sleeve was developed, targeting five muscles of interest in rehabilitation and sport science. An experimental validation was performed to assess the accuracy of signal detection during dynamic exercises, including sit-to-stand, leg extension, calf raise, walking, and cycling. Results. The electrodes can resist up to 500 stretch cycles. Tests on five subjects revealed excellent contact impedance, and cross-correlation between sEMG envelopes simultaneously detected from the leg muscles by the textile and Ag/AgCl electrodes was generally greater than 0.9, which proves that it is possible to obtain good quality signals with performance comparable with disposable electrodes. Conclusions. An effective technique to embed polymer-based electrodes in stretchable smart garments was presented, revealing good performance for dynamic sEMG detections. Significance. The achieved results pave the way to the integration of unobtrusive electrodes, obtained by screen printing of conductive polymers, into technical fabrics for rehabilitation and sport monitoring, and in general where the detection of sEMG in dynamic conditions is necessary

    Percutaneous Vertebral Reconstruction (PVR) Technique of Pathological Compression Fractures: An Innovative Combined Treatment of Microwave Ablation, Bilateral Expandable Titanium SpineJack Implants Followed by Vertebroplasty

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    Background: to retrospectively evaluate safety and efficacy of combined microwave ablation (MWA) and bilateral expandable titanium SpineJack (SJ) implants followed by vertebroplasty (VP) for the treatment of painful thoracolumbar pathological vertebral compression fracture. (2) Methods: from July 2017 to October 2022, twenty-eight patients (13 women and 15 men; mean age 68 ± 11 years) with a history of primary neoplasm and thirty-six painful vertebral metastases with vertebral compression fracture underwent combined MWA and bilateral expandable titanium SpineJack implants with vertebroplasty. We analyzed safety through complications rate, and efficacy through vertebral height restoration and pain decrease, evaluated using a visual analogue scale (VAS), and Functional Mobility Scale (FMS), and local tumor control. Contrast-enhanced CT scans were performed at 1, 3, and 6 months and a contrast-enhanced spine MRI at 6 months after the procedure. (3) Results: Technical success rate was 100%. No procedure-related major complications or death occurred. Vertebral height restoration was observed in 22 levels (58%), with a mean anterior height restoration of 2.6 mm ± 0.6 and a mean middle height restoration of 4.4 mm ± 0.6 (p < 0.001). Mean VAS score of pain evaluation on the day before treatment was 6.3 ± 1.5 (range 4–9). At the 6-month evaluation, the median VAS score for pain was 0.4 ± 0.6 (range 0–2) with a mean reduction of 93.65% (6.8 ± 0.7 vs. 0.4 ± 0.6; p < 0.000) compared with baseline evaluation. Contrast-enhanced CT scans were performed at 1, 3, and 6 months and a contrast-enhanced spine MRI was performed at 6 months after the procedure, showing no local recurrence, implant displacement, or new fractures in the treated site. (4) Conclusions: combined microwave ablation and bilateral expandable titanium SpineJack implants with vertebroplasty is a safe and effective procedure for the treatment of pathological compressive vertebral fractures. The vertebral stabilization achieved early and persistent pain relief, increasing patient mobility, improving recovery of walking capacity, and providing local tumor control

    Overcoming barriers to the effective management of severe asthma in Italy

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    Introduction: People with severe asthma (SA) often have poor disease control and quality of life, and are at high risk of exacerbations, lung function decline and asthma-related death. The present expert opinion article aimed to identify unmet needs in the management of SA in Italy, and propose possible solutions to address these needs. Methods: At five multidisciplinary events in Italy, attendees identified factors that interfered with the effective management of SA and suggested how these barriers could be overcome. A core group of 12 Italian experts (pulmonologists, general practitioners, allergists, payers and patients) identified the main issues and proposed possible solutions based on the results from the meetings and relevant articles from the literature. Results and Conclusions: We reviewed the gap between real-world practice and guide-lines, oral corticosteroid overuse, SA-related mortality, and barriers to effective SA treat-ment. Common themes were lack of awareness about SA among both patients and clinicians, and lack of networking/information exchange between those involved in the treatment of SA. Participants agreed on the need to implement patient education and create multidisciplinary groups of specialists to improve SA management through multidisciplinary educational initiatives, meetings with local experts, development of a flow chart for referral/connection with local experts and specialized centers. Clinical instruments that might help specialists improve SA management included referral networks, integrated care pathways, phenotyping and treatment algorithms, exacerbation tracking, and examination of electronic medical records for patients with uncontrolled asthma. The following actions need to be implemented in Italy: i) maximize the use of advanced therapies, eg, biologics; ii) increase/improve education for physicians and patients; iii) improve multidisciplinary communication and care coordination; iv) introduce regional and local protocols for SA diagnosis and treatment; and v) change the structure of healthcare services to reduce specialist waiting times and facilitate access to biologic therapies

    Who shares health and medical scholarly articles on Facebook?

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    Over a million journal articles had been shared on public Facebook pages by 2017, but little is known about who is sharing (posting links to) these papers and whether mention counts could be an impact indicator. This study classified users who had posted about 749 links on Facebook before October 2017 mentioning 500 medical and health-related research articles, obtained using altmetric.com data. Most accounts (68%) belonged to groups, including online communities, journals, academic organizations, and societies. Of individual profiles, academics accounted for only 4%, but the largest group were health care professionals (16%). More than half (58%) of all Facebook accounts examined were not academic. The non-academic dominance suggests that public Facebook posts linking to health-related articles are mostly used to facilitate scientific knowledge flow between nonacademic professionals and the public. Therefore, Facebook mention counts may be a combined academic and non-academic attention indicator in the health and medical domains

    Ketoacidosis at diagnosis in childhood-onset diabetes and the risk of retinopathy 20years later

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    Aims To investigate on the relationship between severity of ketoacidosis, an important risk factor for C-peptide preservation, and long-term microvascular complications in childhood-onset type 1 diabetes mellitus (T1DM). Methods 230 childhood-onset diabetic patients (177 pre-pubertal), aged 7.0 \ub1 3.8 years followed for at least 15 years after their diagnosis, were enrolled. Clinical and laboratory data at diagnosis, and C-peptide levels in a subset of patients, were compared with the severity of retinopathy and nephropathy, after a mean of 19.6 \ub1 3.8 years of disease. Digital retinal photographs were taken in all patients, and centrally graded. Repeated measurements of HbA1c and microalbuminuria for the whole duration of diabetes were collected in over half of the cases. Results Out of 230 patients, those with the lowest age at diagnosis had the most severe DKA and clinical conditions (p < 0.05), and lower C-peptide levels (p < 0.0001) at diagnosis. There was a significant relationship between pH and clinical severity (r = - 0.783, p < 0.0001), and between pH and C-peptide levels (r = 0.278, p < 0.05). The severity of ketoacidosis had no relationship with subsequent lifetime HbA1c values and long-term microvascular complications. In logistic regression analysis, the only variables that independently influenced severity of retinopathy were lifetime HbA1c (B = 0.838, p < 0.001), duration of disease (B = 0.208, p < 0.005) and age at diagnosis (B = 0.116, p < 0.05). Conclusions The degree of metabolic derangement at diagnosis is not associated with retinopathy and nephropathy in childhood-onset T1DM. Age at diagnosis seems to be an important variable to be considered when evaluating the long-term effects of residual beta-cell function

    Integrating demand uncertainty in inventory routing for recyclable waste collection

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    Osteoblast cell adhesion to the extracellular matrix is established through two main pathways: one is mediated by the binding between integrin and a minimal adhesion sequence (RGD) on the extracellular protein, the other is based on the interactions between transmembrane proteoglycans and heparin-binding sequences found in many matrix proteins. The aim of this study is the evaluation in an in vivo endosseous implant model of the early osteogenic response of the peri-implant bone to a biomimetic titanium surface functionalized with the retro-inverso 2DHVP peptide, an analogue of Vitronectin heparin binding site. The experimental plan is based on a bilateral study design of Control and 2DHVP implants inserted respectively in the right and left femur distal metaphysis of adult male Wistar rats (n=16) weighing about 300 gr and evaluated after 15 days. Fluorochromic bone vital markers, were given at specific time frame, in order to monitor the dynamic of new bone deposition. The effect inducted by the peptidomimetic coating on the surrounding bone were qualitatively and quantitatively evaluated by means of static and dynamic histomorphometric analyses performed within three concentric and subsequent circular Regions of Interest (ROI) of equivalent thickness (220 μm), ROI1 adjacent to the interface, ROI2, the middle, and ROI3 the farthest. The data indicated that these functionalized implants stimulated a higher bone apposition rate (p<0,01) and larger and rapid osteoblast activation in terms of mineralising surface within ROI1 compared to the Control (p<0,01). These higher osteoblast recruitment and activation leads to a greater bone to implant contact reached for DHVP samples (p<0,5). This represents an initial stimulus of the osteogenic activity that might results in a faster and better osteointegration process
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