[Spanish validation of the Autonomic Standards Assessment Form in spinal cord injuries]. / Validación española del cuestionario Autonomic Standards Assessment Form en la lesión medular.

INTRODUCTION AND OBJECTIVES: Autonomic nervous system (ANS) dysfunction in patients with spinal cord injury (SCI) severely impacts morbidity and mortality. However, research initiatives aiming to gain insight into the direct impact of ANS dysfunction on health outcomes in persons with SCI are still lacking. Thus, this study had 2main objectives: 1) to translate into Spanish the revised edition of the International Standards on documentation of remaining Autonomic Function after SCI (ISAFSCI), and 2) to describe the impact of ANS dysfunction in a sample of SCI patients. MATERIAL AND METHODS: Cross-sectional observational pilot study in 51 traumatic SCI patients (> 1 year after injury). Demographic, medical and ISAFSCI data were studied. RESULTS: The Spanish version of the ISAFSCI showed that the most altered systems in the sample were sweating control (above-lesion hyperhidrosis in 33.3%; below-lesion hyperhidrosis in 17.6%; below-lesion hypohidrosis in 21.6%) and temperature control (hyperthermia in 76.5%). In addition, 74.5% of the sample had complete loss of control of the lower urinary tract, and 82.4% had no control of the bowel. Finally, genital arousal was reflex in 47.1% and orgasm and ejaculation were reduced or altered in most of the patients (92.2% and 84.3%, respectively). CONCLUSION: The Spanish version of the ISAFSCI is a useful and practical tool, and can be employed in clinical practice to assess ANS function in patients with SCI. Understanding the role of ANS in persons with SCI is crucial to improve their health status and reduce secondary complications post-SCI, and consequently help to improve the clinical management in these individuals.

Oral health in Alzheimer's disease: a multicenter case-control study.

OBJECTIVES: The aim of this case-control study was to carry out an oral health assessment on a group of Alzheimer's patients and to establish a hypothesis regarding the implication of the characteristics of the disease and the treatment of oral health. MATERIALS AND METHODS: A total of 70 Alzheimer's patients, residents at the Alzheimer Center Reina Sofia Foundation (Madrid, Spain) and at the Alzheimer State Reference Center (Salamanca, Spain), and 36 controls (companions/acquaintances), were studied by oral examination and saliva sampling. The oral health indices DMFT/DMFS, CPI, the prosthetic condition, oral hygiene, saliva volume, and pH, as well as the specific microbiological parameters governing the risk of developing caries were assessed. RESULTS: Alzheimer's patients exhibited, as compared to the control group, (1) fewer teeth (10.9 ± 10.5 vs 23.7 ± 6.5), (2) fewer obturations (2.2 ± 3.4 vs 6.6 ± 5.6), (3) fewer periodontally healthy sextants (0.1 ± 0.4 vs 1.4 ± 2.2), (4) worse oral hygiene (43.1 vs 72.2% brushed), (5) greater use of removable prostheses (47.8 vs 8.4%), (6) higher incidence of candida infection (11.8 vs 0.0%) and cheilitis (15.9 vs 0.0%), (7) lower salivary flow (0.6 ± 0.6 vs 1.1 ± 0.6), and (8) lower buffering capacity (46 vs 80%). CONCLUSIONS: After taking into account the influence of age, Alzheimer's patients had worse oral health (caries and periodontal disease), more mucosal lesions (cheilitis and candidiasis), and worse saliva quantity and quality. CLINICAL RELEVANCE: Clinicians should be aware of the implications of Alzheimer's disease in oral health, in order to stablish the effective preventive measures and the optimal treatment plan.

Erratum: Theory of Frequency-Filtered and Time-Resolved N-Photon Correlations [Phys. Rev. Lett. 109, 183601 (2012)].

This corrects the article DOI: 10.1103/PhysRevLett.109.183601.

Physical and Psychosocial Functions of Adults with Lower Limb Congenital Deficiencies and Amputations in Childhood.

Objectives. (1) To describe the epidemiological and medical features of a sample with LLA and LLD in childhood and (2) to explore their relationship with subsequent physical and psychosocial functions in adulthood. Methods. Cross-sectional survey. Demographics, medical data, Locomotor Capabilities Index (LCI), and Discomfort-Engagement in Everyday Activities Involving Revealing the Body Scale (D-EEARB) were collected from thirty-two adults who suffered from LLA in childhood or LLD. Results. Most of the sample (53.1% males) was working (84.4%), living independently (75%), and single (75%). Mean age was 33.16 (SD = 7.64, range 18-50). Leading causes for LLA were traumatic (40.6%) and oncologic (25%). LLD was present in 6 cases (18.8%). LCI scores revealed a high performance among males (t 17,464 = 2.976, p = .008). D-EEARB scores showed that 56.25% stated feeling "quite" or "totally comfortable" in situations which involved revealing their body, but 43.75% stated the contrary ("uncomfortable" or "very uncomfortable"). LLD and traumatic LLA show higher scores in D-EEARB than vascular and oncological LLA (χ (2) = 7.744, df = 3, p = .05). Conclusions. Adults suffering from LLDs and LLAs during childhood seem to perform well once they are adults. However, 43.75% of patients express considerable discomfort in situations that involve revealing the body.

Type of tumour, gender and time since diagnosis affect differently health-related quality of life in adolescent survivors.

Research findings about health-related quality of life (HRQoL) of childhood cancer survivors are mixed and the features which could modulate these results have not been investigated rigorously. This research aims to improve the knowledge on these topics. Thus, HRQoL between central nervous system (CNST) and non-central nervous system (non-CNST) adolescent cancer survivors was compared. The influence of selected factors (gender and years since diagnosis) on HRQoL was also analysed. In a cross-sectional design, 78 survivors (12-20 years) who were ≥ 1 year free of oncological treatment answered the self-reported version of the KIDSCREEN-52. HRQoL mean scores of CNST survivors were lower in comparison with non-CNST in physical well-being and social support and peers dimensions. Furthermore, female gender was also related to lower HRQoL scores for both types of tumours in physical well-being and autonomy dimensions. Additionally, scores on psychological well-being, social support and peers, parent relations and home life and school environment dimensions decrease with length of time from diagnosis. Therefore, diagnosis of CNST and gender were related to lower HRQoL among survivors in some dimensions, whereas time from diagnosis was related to impaired HRQoL in other features. These results can help to design tailored interventions and psychosocial guidelines to follow-up survivors.

Emitters of N-photon bundles.

Controlling the ouput of a light emitter is one of the basic tasks of photonics, with landmarks such as the laser and single-photon sources. The development of quantum applications makes it increasingly important to diversify the available quantum sources. Here, we propose a cavity QED scheme to realize emitters that release their energy in groups, or "bundles" of N photons, for integer N. Close to 100% of two-photon emission and 90% of three-photon emission is shown to be within reach of state of the art samples. The emission can be tuned with system parameters so that the device behaves as a laser or as a N-photon gun. The theoretical formalism to characterize such emitters is developed, with the bundle statistics arising as an extension of the fundamental correlation functions of quantum optics. These emitters will be useful for quantum information processing and for medical applications.

Theory of strong coupling between quantum emitters and propagating surface plasmons.

Here we present the theoretical foundation of the strong coupling phenomenon between quantum emitters and propagating surface plasmons observed in two-dimensional metal surfaces. For that purpose, we develop a quantum framework that accounts for the coherent coupling between emitters and surface plasmons and incorporates the presence of dissipation and dephasing. Our formalism is able to reveal the key physical mechanisms that explain the reported phenomenology and also determine the physical parameters that optimize the strong coupling. A discussion regarding the classical or quantum nature of this phenomenon is also presented.

Theory of frequency-filtered and time-resolved N-photon correlations.

A theory of correlations between N photons of given frequencies and detected at given time delays is presented. These correlation functions are usually too cumbersome to be computed explicitly. We show that they are obtained exactly through intensity correlations between two-level sensors in the limit of their vanishing coupling to the system. This allows the computation of correlation functions hitherto unreachable. The uncertainties in time and frequency of the detection, which are necessary variables to describe the system, are intrinsic to the theory. We illustrate the power of our formalism with the example of the Jaynes-Cummings model, by showing how higher order photon correlations can bring new insights into the dynamics of open quantum systems.

Frictionless flow in a binary polariton superfluid.

We study the properties of a binary microcavity polariton superfluid coherently injected by two lasers at different momenta and energies. The crossover from the supersonic to the subsonic regime, where motion is frictionless, is described by evaluating the linear response of the system to a weak defect potential. We show that the coupling between the two components requires that either both components flow without friction or both scatter against the defect, though scattering can be small when the two fluids are weakly coupled. By analyzing the drag force exerted on a defect, we give a recipe to experimentally address the crossover from the supersonic to the subsonic regime.

Control and ultrafast dynamics of a two-fluid polariton switch.

We investigate the cross interactions in a two-component polariton quantum fluid coherently driven by two independent pumping lasers tuned at different energies and momenta. We show that both the hysteresis cycles and the on-off threshold of one polariton signal can be entirely controlled by a second polariton fluid. Furthermore, we study the ultrafast switching dynamics of a driven polariton state, demonstrating the ability to control the polariton population with an external laser pulse, in less than a few picoseconds.

Onset and dynamics of vortex-antivortex pairs in polariton optical parametric oscillator superfluids.

We study, both theoretically and experimentally, the occurrence of topological defects in polariton superfluids in the optical parametric oscillator (OPO) regime. We explain in terms of local supercurrents the deterministic behavior of both the onset and dynamics of vortex-antivortex pairs generated by perturbing the system with a pulsed probe. Using a generalized Gross-Pitaevskii equation, including photonic disorder, pumping and decay, we elucidate the reason why topological defects form in couples and can be detected by direct visualizations in multishot OPO experiments.

Entanglement of two qubits mediated by one-dimensional plasmonic waveguides.

We investigate qubit-qubit entanglement mediated by plasmons supported by one-dimensional waveguides. We explore both the situation of spontaneous formation of entanglement from an unentangled state and the emergence of driven steady-state entanglement under continuous pumping. In both cases, we show that large values for the concurrence are attainable for qubit-qubit distances larger than the operating wavelength by using plasmonic waveguides that are currently available.

Spontaneous and triggered vortices in polariton optical-parametric-oscillator superfluids.

We study nonequilibrium polariton superfluids in the optical-parametric-oscillator regime by using a Gross-Pitaevskii equation with pumping and decay. We identify a regime above the optical-parametric-oscillator threshold, where the system undergoes spontaneous symmetry breaking and is unstable towards vortex formation without any rotating drive. Stable vortex solutions differ from metastable ones; the latter can persist but can be triggered only externally. Both spontaneous and triggered vortices are characterized by a generalized healing length, specified by the optical-parametric-oscillator parameters only.

Emission polarization control in semiconductor quantum dots coupled to a photonic crystal microcavity.

We study the optical emission of single semiconductor quantum dots weakly coupled to a photonic-crystal micro-cavity. The linearly polarized emission of a selected quantum dot changes continuously its polarization angle, from nearly perpendicular to the cavity mode polarization at large detuning, to parallel at zero detuning, and reversing sign for negative detuning. The linear polarization rotation is qualitatively interpreted in terms of the detuning dependent mixing of the quantum dot and cavity states. The present result is relevant to achieve continuous control of the linear polarization in single photon emitters.

Effect of pure dephasing on the Jaynes-Cummings nonlinearities.

We study the effect of pure dephasing on a two-level system in strong coupling in the nonlinear regime with the single mode of a cavity. The photoluminescence spectrum of the cavity has a robust tendency to display triplet structures, instead of the expected Jaynes-Cummings pairs of doublets at the incommensurate frequencies +/- (square root n +/- square root (n-1)) for integer n. We discuss recent experimental works that may already manifest signatures of single photon nonlinearities.

Polariton condensates put in motion.

We present several examples of the interesting phenomenology shown by a moving polariton condensate in semiconductor microcavities. The superfluid behavior is probed by colliding the polariton condensate against physical obstacles in the form of natural defects of the sample, demonstrating a clear suppression of scattering when the speed of the flow lies below the critical velocity. At higher velocities Cerenkov-like shock waves around the defect and disruption of the condensate are also observed.

Dynamics of the formation and decay of coherence in a polariton condensate.

We study the dynamics of the formation and decay of a condensate of microcavity polaritons. We investigate the relationship among the number of particles, the emission linewidth, and its degree of linear polarization, which serves as the order parameter. Tracking the condensate formation, we show that coherence is not determined only by occupation of the ground state, bringing new insights into the determining factors for Bose-Einstein condensation.

Collective fluid dynamics of a polariton condensate in a semiconductor microcavity.

Semiconductor microcavities offer unique systems in which to investigate the physics of weakly interacting bosons. Their elementary excitations, polaritons-mixtures of excitons and photons-can accumulate in macroscopically degenerate states to form various types of condensate in a wide range of experimental configurations, under either incoherent or coherent excitation. Condensates of polaritons have been put forward as candidates for superfluidity, and the formation of vortices as well as elementary excitations with linear dispersion are actively sought as evidence to support this. Here, using a coherent excitation triggered by a short optical pulse, we have created and set in motion a macroscopically degenerate state of polaritons that can be made to collide with a variety of defects present in the microcavity. Our experiments show striking manifestations of a coherent light-matter packet, travelling at high speed (of the order of one per cent of the speed of light) and displaying collective dynamics consistent with superfluidity, although one of a highly unusual character as it involves an out-of-equilibrium dissipative system. Our main results are the observation of a linear polariton dispersion accompanied by diffusionless motion; flow without resistance when crossing an obstacle; suppression of Rayleigh scattering; and splitting into two fluids when the size of the obstacle is comparable to the size of the wave packet. This work opens the way to the investigation of new phenomenology of out-of-equilibrium condensates.

High-speed gel microelectrophoresis, a new and easy approach for detection of PCR-amplified microbial DNA from environmental and clinical samples in microgels using conventional equipment.

AIMS: Microelectrophoresis allows the detection of DNA bands using minimal amounts of sample in a short time, but commonly requires the use of special equipment which is not available in all laboratories. This fact has limited the application of this technique in microbiology despite its advantages. In this work, we describe a new approach to perform gel microelectrophoresis, named high-speed gel microelectrophoresis (HSGME), and its application for rapid detection of bacteria, protozoa and viruses in clinical, vegetal and environmental samples. METHODS AND RESULTS: Aliquots of 0.4-1 microl of PCR product were loaded in 2 cm 1% agarose microgels and electrophoresed at high voltage (125 V cm(-1)) in conventional submarine horizontal mini-slabs. By using HSGME, single-DNA bands obtained after specific-PCR useful in diagnosis of different diseases caused by micro-organisms were detected in 5 min. CONCLUSIONS: HSGME is a rapid and easy procedure applicable to detection of microbial genes, which is carried out using conventional equipment and thus can be performed in any research and diagnostic laboratory. SIGNIFICANCE AND IMPACT OF THE STUDY: The performance of HSGME saves up to 90% time, material and energy costs, as well as laboratory hazardous wastes including carcinogenic agents used for visualizing DNA bands.