124 research outputs found
Aquatic Therapy after Incomplete Spinal Cord Injury: Gait Initiation Analysis Using Inertial Sensors
: Populations with potential damage to somatosensory, vestibular, and visual systems or poor motor control are often studied during gait initiation. Aquatic activity has shown to benefit the functional capacity of incomplete spinal cord injury (iSCI) patients. The present study aimed to evaluate gait initiation in iSCI patients using an easy-to-use protocol employing four wearable inertial sensors. Temporal and acceleration-based anticipatory postural adjustment measures were computed and compared between dry-land and water immersion conditions in 10 iSCI patients. In the aquatic condition, an increased first step duration (median value of 1.44 s vs. 0.70 s in dry-land conditions) and decreased root mean squared accelerations for the upper trunk (0.39 m/s2 vs. 0.72 m/s2 in dry-land conditions) and lower trunk (0.41 m/s2 vs. 0.85 m/s2 in dry-land conditions) were found in the medio-lateral and antero-posterior direction, respectively. The estimation of these parameters, routinely during a therapy session, can provide important information regarding different control strategies adopted in different environments
Relativistic Hamiltonian Dynamics and Few-Nucleon Systems
We present a preliminary calculation of the electromagnetic form factors of
He and H, performed within the Light-Front Hamiltonian Dynamics.
Relativistic effects show their relevance even at the static limit, increasing
at higher values of momentum transfer, as expected.Comment: 6 pages, 4 figures. Proceedings of 20th European Conference on
Few-Body Problems in Physics; to be published in Few-Body System
Stenting versus balloon dilatation in patients with tracheal benign stenosis: The STROBE trial
Background: It is well known that benign tracheal stenosis represents an obstacle to open surgery, and that its treatment could be challenging. Two endoscopic techniques have so far been adopted to restore tracheal patency: balloon dilatation (BA) through laryngoscopy, and tracheal stenting (ST) with rigid bronchoscopy. The main objective of this study was to compare the efficacy of BA and ST to treat benign tracheal stenosis not eligible for surgery. We also compared the rate of adverse events in the two treatment groups. Methods: A retrospective, observational cohort study was carried out at the University Hospital of Modena (Italy) from November 2012 to November 2017 in two separate departments. Patients were considered to be “stabilized” (primary outcome) if they did not report significant respiratory symptoms, or restenosis in the long-term (2 years) following the endoscopic procedure. Results: Sixty-six patients were included in the study (33 in the BA and 33 in the ST group, respectively). Unadjusted Kaplan–Meier estimates showed a greater therapeutic effect of ST compared to BA at 2 years (hazard ratio = 3.9 95%CI [1.5–9.8], p =.01). After adjusting for confounders, stratified analyses showed that this effect was significant in patients with complex stenosis, idiopathic etiology, and degree of stenosis >70%. Compared with BA, ST showed a higher rate of adverse events (p =.01). Conclusions: Compared to BA, ST seems to be more effective in achieving stabilization of tracheal patency in complex benign tracheal stenosis, although burdened with a significantly higher number of adverse effects. These findings warrant future prospective study for confirmation. Level of evidence: 3
Molecular Mechanisms and Physiological Changes behind Benign Tracheal and Subglottic Stenosis in Adults
Laryngotracheal stenosis (LTS) is a complex and heterogeneous disease whose pathogenesis remains unclear. LTS is considered to be the result of aberrant wound-healing process that leads to fibrotic scarring, originating from different aetiology. Although iatrogenic aetiology is the main cause of subglottic or tracheal stenosis, also autoimmune and infectious diseases may be involved in causing LTS. Furthermore, fibrotic obstruction in the anatomic region under the glottis can also be diagnosed without apparent aetiology after a comprehensive workup; in this case, the pathological process is called idiopathic subglottic stenosis (iSGS). So far, the laryngotracheal scar resulting from airway injury due to different diseases was considered as inert tissue requiring surgical removal to restore airway patency. However, this assumption has recently been revised by regarding the tracheal scarring process as a fibroinflammatory event due to immunological alteration, similar to other fibrotic diseases. Recent acquisitions suggest that different factors, such as growth factors, cytokines, altered fibroblast function and genetic susceptibility, can all interact in a complex way leading to aberrant and fibrotic wound healing after an insult that acts as a trigger. However, also physiological derangement due to LTS could play a role in promoting dysregulated response to laryngo-tracheal mucosal injury, through biomechanical stress and mechanotransduction activation. The aim of this narrative review is to present the state-of-the-art knowledge regarding molecular mechanisms, as well as mechanical and physio-pathological features behind LTS
Organic nanofibers embedding stimuli-responsive threaded molecular components
While most of the studies on molecular machines have been performed in
solution, interfacing these supramolecular systems with solid-state
nanostructures and materials is very important in view of their utilization in
sensing components working by chemical and photonic actuation. Host polymeric
materials, and particularly polymer nanofibers, enable the manipulation of the
functional molecules constituting molecular machines, and provide a way to
induce and control the supramolecular organization. Here, we present
electrospun nanocomposites embedding a self-assembling rotaxane-type system
that is responsive to both optical (UV-visible light) and chemical (acid/base)
stimuli. The system includes a molecular axle comprised of a dibenzylammonium
recognition site and two azobenzene end groups, and a dibenzo[24]crown-8
molecular ring. The dethreading and rethreading of the molecular components in
nanofibers induced by exposure to base and acid vapors, as well as the
photoisomerization of the azobenzene end groups, occur in a similar manner to
what observed in solution. Importantly, however, the nanoscale mechanical
function following external chemical stimuli induces a measurable variation of
the macroscopic mechanical properties of nanofibers aligned in arrays, whose
Young's modulus is significantly enhanced upon dethreading of the axles from
the rings. These composite nanosystems show therefore great potential for
application in chemical sensors, photonic actuators and environmentally
responsive materials.Comment: 39 pages, 16 figure
Utilization of Renewable Biomass and Waste Materials for Production of Environmentally-Friendly, Bio-based Composites
The introduction of renewable biomass into a polymer matrix is an option competing with other
possibilities, such as energy recovery and/or re-use in the carbonized state, or production of
chemicals, such as, in the case of ligno-cellulosic waste, concentrates on the production of simple
sugars, then possibly leading to the development of biopolymers. These competitive applications
have also some interest and market, however with a considerable energy, water and materials
consumption, due also to the not always high yielding. Other possibilities for renewable biomass are
therefore being used as fillers to increase mechanical performance of polymers or to allow e.g., the
absorption of toxic chemicals. This review concentrates on the use of biomass as close as possible
to the “as received” state, therefore avoiding whenever suitable any thermal treatment. More
specifically, it focuses on its introduction into the three categories of oil-based (or bio-based
replacement) of engineered polymers, into industrial biopolymers, such as poly(lactic acid) (PLA)
and self-developed biopolymers, such as thermoplastic starch (TPS)
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