Efficient generation and sorting of orbital angular momentum eigenmodes of light by thermally tuned q-plates

We present methods for generating and for sorting specific orbital angular momentum (OAM) eigenmodes of a light beam with high efficiency, using a liquid crystal birefringent plate with unit topological charge, known as \qo{q-plate}. The generation efficiency has been optimized by tuning the optical retardation of the q-plate with temperature. The measured OAM $m=\pm2$ eigenmodes generation efficiency from an input TEM$_{00}$ beam was of 97%. Mode sorting of the two input OAM $m=\pm2$ eigenmodes was achieved with an efficiency of 81% and an extinction-ratio (or cross-talk) larger than 4.5:1.Comment: 4 pages, 3 Figures and 1 table. Submitte

effect of intrathecal baclofen botulinum toxin type a and a rehabilitation programme on locomotor function after spinal cord injury a case report

Objective: a few studies have reported the use of botulinum toxin injections after spinal cord injury, as this is the gold standard to treat focal spasticity. We report such a case here. Case report: a 38-year-old woman who had become paraplegic and care-dependent secondary to cervico-thoracic intramedullary ependymoma, presented 8 months later with painful lower limb spasticity, which was being treated with oral anti-spastic and benzodiazepine drugs with no therapeutic effect. We treated the patient with intrathecal baclofen to reduce her spasticity and in order to avoid the major side-effects of high dosages of oral baclofen. after motor rehabilitation programmes, which included functional ele

ACOUSTIC ANALYSIS OF SWALLOWING SOUNDS: A NEW TECHNIQUE FOR ASSESSING DYSPHAGIA

Objective: To perform acoustic analysis of swallowing sounds, using a microphone and a notebook computer system, in healthy subjects and patients with dysphagia affected by neurological diseases, testing the positive/negative predictive value of a pathological pattern of swallowing sounds for penetration/aspiration. Design: Diagnostic test study, prospective, not blinded, with the penetration/aspiration evaluated by fibreoptic endo scopy of swallowing as criterion standard. Subjects: Data from a previously recorded database of normal swallowing sounds for 60 healthy subjects according to gender, age, and bolus consistency was compared with those of 15 patients with dysphagia from a university hospital referral centre who were affected by various neurological diseases. Methods: Mean duration of the swallowing sounds and postswallowing apnoea were recorded. Penetration/aspiration was verified by fibreoptic endoscopy of swallowing in all patients with dysphagia. Results: The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between patients with dysphagia and healthy patients. We also described patterns of swallowing sounds and tested the negative/positive predictive values of post-swallowing apnoea for penetration/aspiration verified by fibreoptic endoscopy of swallowing (sensitivity 0.67 (95% confidence interval 0.24–0.94); specificity 1.00 (95% confidence interval 0.56–1.00)). Conclusion: The proposed technique for recording and measuring swallowing sounds could be incorporated into the bedside evaluation, but it should not replace the use of more diagnostic and valuable measures

Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons

Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here, we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, and we show that it rapidly approaches a multiple of the Zak phase in the long time limit. Then we measure the Zak phase in a photonic quantum walk, by direct observation of the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe, and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general, as it can be applied to all one-dimensional platforms simulating static or Floquet chiral systems.Comment: 10 pages, 7 color figures (incl. appendices) Close to the published versio

effectiveness of switching therapy from complexing protein containing botulinum toxin type a to a formulation with low immunogenicity in spasticity after stroke a case report

Objective: some patients receiving botulinum toxin type a therapy develop immunological resistance due to the production of neutralizing antibodies against the neurotoxin, thus partially or completely reducing the therapeutic effect. Case report: We report here neurophysiological and clinical findings for a 58-year-old man treated with botulinum toxin type A for spasticity after ischaemic stroke, who became a secondary non-responder patient. subsequent treatment with a different preparation of botulinum toxin type A had a great therapeutic effect on his spasticity. the muscles injected and the dosages were the same for each treatment, but evaluation with the Modified Ashworth Scale after treatment with the second preparation showed a reduction of approximately 2 points compared with the first examination. The clinical results were also supported by extensor digitorum brevis testing of the right muscle, which showed a reduction in compound muscle action potential, whereas it was unchanged in the non-injected muscle. No side-effects were reported, and after 1 year of treatment with this formulation clinical benefits were still evident. Conclusion: the neurophysiological and clinical results obtained in this patient suggest that switching therapy from a complexing protein-containing product to a product potentially free of complexing proteins, which has low immunogenicity, may be a viable therapeutic option in secondary non-responder patients

Realignment-enhanced coherent anti-Stokes Raman scattering (CARS) and three-dimensional imaging in anisotropic fluids

We apply coherent anti-Stokes Raman Scattering (CARS) microscopy to characterize director structures in liquid crystals.Comment: 14 pages, 11 figure

Acoustic analysis of swallowing sounds: A new technique for assessing dysphagia

Objective: To perform acoustic analysis of swallowing sounds, using a microphone and a notebook computer system, in healthy subjects and patients with dysphagia affected by neurological diseases, testing the positive/negative predictive value of a pathological pattern of swallowing sounds for penetration/aspiration. Design: Diagnostic test study, prospective, not blinded, with the penetration/aspiration evaluated by fibreoptic endo scopy of swallowing as criterion standard. Subjects: Data from a previously recorded database of normal swallowing sounds for 60 healthy subjects according to gender, age, and bolus consistency was compared with those of 15 patients with dysphagia from a university hospital referral centre who were affected by various neurological diseases. Methods: Mean duration of the swallowing sounds and postswallowing apnoea were recorded. Penetration/aspiration was verified by fibreoptic endoscopy of swallowing in all patients with dysphagia. Results: The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between patients with dysphagia and healthy patients. We also described patterns of swallowing sounds and tested the negative/positive predictive values of post-swallowing apnoea for penetration/aspiration verified by fibreoptic endoscopy of swallowing (sensitivity 0.67 (95% confidence interval 0.24–0.94); specificity 1.00 (95% confidence interval 0.56–1.00)). Conclusion: The proposed technique for recording and measuring swallowing sounds could be incorporated into the bedside evaluation, but it should not replace the use of more diagnostic and valuable measures

Effectiveness of Switching Therapy from Complexing Protein-containing Botulinum Toxin Type A to a Formulation with Low Immunogenicity in Spasticity after Stroke: A case report

Objective: some patients receiving botulinum toxin type a therapy develop immunological resistance due to the production of neutralizing antibodies against the neurotoxin, thus partially or completely reducing the therapeutic effect. Case report: We report here neurophysiological and clinical findings for a 58-year-old man treated with botulinum toxin type A for spasticity after ischaemic stroke, who became a secondary non-responder patient. subsequent treatment with a different preparation of botulinum toxin type A had a great therapeutic effect on his spasticity. the muscles injected and the dosages were the same for each treatment, but evaluation with the Modified Ashworth Scale after treatment with the second preparation showed a reduction of approximately 2 points compared with the first examination. The clinical results were also supported by extensor digitorum brevis testing of the right muscle, which showed a reduction in compound muscle action potential, whereas it was unchanged in the non-injected muscle. No side-effects were reported, and after 1 year of treatment with this formulation clinical benefits were still evident. Conclusion: the neurophysiological and clinical results obtained in this patient suggest that switching therapy from a complexing protein-containing product to a product potentially free of complexing proteins, which has low immunogenicity, may be a viable therapeutic option in secondary non-responder patients

The unexpected resurgence of Weyl geometry in late 20-th century physics

Weyl's original scale geometry of 1918 ("purely infinitesimal geometry") was withdrawn by its author from physical theorizing in the early 1920s. It had a comeback in the last third of the 20th century in different contexts: scalar tensor theories of gravity, foundations of gravity, foundations of quantum mechanics, elementary particle physics, and cosmology. It seems that Weyl geometry continues to offer an open research potential for the foundations of physics even after the turn to the new millennium.Comment: Completely rewritten conference paper 'Beyond Einstein', Mainz Sep 2008. Preprint ELHC (Epistemology of the LHC) 2017-02, 92 pages, 1 figur

Optimal quantum cloning of orbital angular momentum photon qubits via Hong-Ou-Mandel coalescence

The orbital angular momentum (OAM) of light, associated with a helical structure of the wavefunction, has a great potential for quantum photonics, as it allows attaching a higher dimensional quantum space to each photon. Hitherto, however, the use of OAM has been hindered by its difficult manipulation. Here, exploiting the recently demonstrated spin-OAM information transfer tools, we report the first observation of the Hong-Ou-Mandel coalescence of two incoming photons having nonzero OAM into the same outgoing mode of a beam-splitter. The coalescence can be switched on and off by varying the input OAM state of the photons. Such effect has been then exploited to carry out the 1 \rightarrow 2 universal optimal quantum cloning of OAM-encoded qubits, using the symmetrization technique already developed for polarization. These results are finally shown to be scalable to quantum spaces of arbitrary dimension, even combining different degrees of freedom of the photons.Comment: 5 pages, 3 figure