Trapping Microparticles in a Structured Dark Focus.

We experimentally demonstrate stable trapping and controlled manipulation of silica microspheres in a structured optical beam consisting of a dark focus surrounded by light in all directions-the dark focus tweezer. Results from power spectrum and potential analysis demonstrate the nonharmonicity of the trapping potential landscape, which is reconstructed from experimental data in agreement to Lorentz-Mie numerical simulations. Applications of the dark tweezer in levitated optomechanics and biophysics are discussed.

Lung cancer survival and sex-specific patterns in Portugal: A population-based analysis.

INTRODUCTION: In Portugal, lung cancer (LC) is the first cause of cancer-related death and of death and disability combined. This study aims to analyze the overall survival (OS) and relative survival (RS) of patients diagnosed with LC in 2009-2011 by socio-demographic and tumor characteristics, and analyze sex-specific patterns. METHODS: We estimated 5-year OS using the Kaplan-Meier method and 5-year net survival through the RS framework. Cox regression modeling was used to determine the hazard ratio (HR) of death associated with each independent variable. FINDINGS: For the 11,523 cases analyzed, median 5-year OS was 264 days (95% confidence interval [CI]: 254.8-273.2), the cumulative OS was 13.6% and RS was 15.1%. Males had a lower median survival (237 days; 95% CI: 228.2-245.7) compared to females (416 days; 95% CI: 384.4-447.6) (p < 0.0001) and lower 5-year RS proportions (12.1% vs. 24.9%). RS progressively decreased with age (41.7% for age-group <40 to 7.2% for ≥80) and stage (66.6% for stage I to 2.4% for stage IV). As predictors of decreased survival, we identified male gender, increasing age >50, histologic types (squamous cell carcinoma, non-small cell lung cancer not otherwise specified, other unspecified and small cell lung cancer), and increasing stage. Compared to women, the risk of death in men was 37.7% higher (HR = 1.386; 95% CI: 1.295-1.484). CONCLUSIONS: The differences between OS and RS were small, reflecting the high lethality of LC. Male gender and older age are factors related to poor prognosis. Histology also plays a role in survival prognosis and varies with gender, but the factor related to the worst survival is stage. Although the study reflects data from a decade ago, and major changes occurred in diagnosis, staging and treatment, particularly for advanced disease, as LC mortality is strongly correlated with late stage diagnosis, all efforts should be made to secure early diagnosis and improve survival prospects.

[Multiple sclerosis in continental Portugal: analysis of spatio-temporal clusters and spatial variations in time trends of hospitalised patients between 2002 and 2013]. / Esclerosis multiple en Portugal continental: analisis de clusters espaciotemporales y variaciones espaciales en tendencias temporales de los ingresados entre 2002 y 2013.

INTRODUCTION: Multiple sclerosis (MS) is a demyelinating and autoimmune disease with variable progression and high risk of hospital admission. In some studies these hospitalizations may be used as surrogate markers of disease progression, however in Portugal, due to organizational asymmetries and clinical safety choices this relationship is not linear. The admission patterns for this pathology can provide relevant data to the design of disease's management strategies and resource allocation. AIM: To characterize hospital admissions for MS in mainland Portugal between 2002 and 2013 through the cases included in the hospital morbidity database with the code ICD-9-CM 340 as primary diagnosis. PATIENTS AND METHODS: In this study mapping techniques, analysis of spatio-temporal clusters and analysis of spatial variations in temporal trends of hospital admission rates for MS were used. RESULTS: Between 2002 and 2013 the rate of annual hospital admission for MS was 82.2/100,000 hospitalizations, with a decreasing trend of 3.73%/year. Seven spatial-temporal clusters were identified with hospital admission rates for this pathology ranging from 2.27 to 4.23 higher than the national rate. In addition, in this time period four areas with increasing trend in hospital admission rate (+ 0.17 to +11.5%) were detected: Sintra-Cascais-Amadora, Serra da Estrela, Alentejo-Algarve and Tras-os-Montes. CONCLUSION: These data demonstrate the expected asymmetry of organizational differences, environmental, genetic and clinical safety choices. This study allowed the identification of areas and evolutionary trends of hospital admission rates for MS, enabling the design of more focused health interventions.

TITLE: Esclerosis multiple en Portugal continental: analisis de clusters espaciotemporales y variaciones espaciales en tendencias temporales de los ingresados entre 2002 y 2013.Introduccion. La esclerosis multiple (EM) es una enfermedad desmielinizante y autoinmune con progresion variable y alto riesgo de hospitalizacion. En algunos estudios, estos ingresos se utilizan como marcadores sustitutivos de la progresion de la enfermedad, pero en Portugal, debido a las asimetrias organizacionales y las opciones de seguridad clinica, esta relacion no es lineal. El patron de ingresos por EM puede proporcionar datos relevantes para el diseño de estrategias de gestion de la enfermedad y asignacion de recursos. Objetivo. Caracterizar los ingresos por EM en Portugal continental entre 2002 y 2013 a traves de los casos constantes en la base de datos de morbilidad hospitalaria con codigo de diagnostico principal CIE-9-MC 340. Pacientes y metodos. Se utilizaron tecnicas de mapeo, analisis de clusters espaciotemporales y analisis de variaciones espaciales en tendencias temporales de la tasa de ingresos por EM. Resultados. Entre 2002 y 2013, la tasa de ingreso anual por EM fue de 82,2 por 100.000 ingresos, con una tendencia decreciente anual del 3,73%. Se identificaron siete clusters espaciotemporales con tasas de ingresos por esta patologia desde 2,27 a 4,23 superiores a la tasa nacional. Ademas, se detectaron cuatro areas con tendencia creciente en la tasa de ingreso en este periodo temporal (+0,17 a +11,5%): Sintra-Cascais-Amadora, Serra da Estrela, Alentejo-Algarve y Tras-os-Montes. Conclusion. Estos resultados demuestran la asimetria esperada por las diferencias organizativas, factores ambientales, geneticos y opciones de seguridad clinica. Permite la identificacion de areas y tendencias evolutivas de las tasas de ingreso por EM, y posibilita el diseño de intervenciones en salud mas enfocadas.

Demonstration of Einstein-Podolsky-Rosen Steering Using Single-Photon Path Entanglement and Displacement-Based Detection.

We demonstrate the violation of an Einstein-Podolsky-Rosen steering inequality developed for single-photon path entanglement with displacement-based detection. We use a high-rate source of heralded single-photon path-entangled states, combined with high-efficiency superconducting-based detectors, in a scheme that is free of any postselection and thus immune to the detection loophole. This result conclusively demonstrates single-photon entanglement in a one-sided device-independent scenario, and opens the way towards implementations of device-independent quantum technologies within the paradigm of path entanglement.

Revealing genuine optical-path entanglement.

How can one detect entanglement between multiple optical paths sharing a single photon? We address this question by proposing a scalable protocol, which only uses local measurements where single photon detection is combined with small displacement operations. The resulting entanglement witness does not require postselection, nor assumptions about the photon number in each path. Furthermore, it guarantees that entanglement lies in a subspace with at most one photon per optical path and reveals genuinely multipartite entanglement. We demonstrate its scalability and resistance to loss by performing various experiments with two and three optical paths. We anticipate applications of our results for quantum network certification.

Nonlinear interaction between single photons.

Harnessing nonlinearities strong enough to allow single photons to interact with one another is not only a fascinating challenge but also central to numerous advanced applications in quantum information science. Here we report the nonlinear interaction between two single photons. Each photon is generated in independent parametric down-conversion sources. They are subsequently combined in a nonlinear waveguide where they are converted into a single photon of higher energy by the process of sum-frequency generation. Our approach results in the direct generation of photon triplets. More generally, it highlights the potential for quantum nonlinear optics with integrated devices and, as the photons are at telecom wavelengths, it opens the way towards novel applications in quantum communication such as device-independent quantum key distribution.

Pulsed source of spectrally uncorrelated and indistinguishable photons at telecom wavelengths.

We report on the generation of indistinguishable photon pairs at telecom wavelengths based on a type-II parametric down conversion process in a periodically poled potassium titanyl phosphate (PPKTP) crystal. The phase matching, pump laser characteristics and coupling geometry are optimised to obtain spectrally uncorrelated photons with high coupling efficiencies. Four photons are generated by a counter-propagating pump in the same crystal and anlysed via two photon interference experiments between photons from each pair source as well as joint spectral and g((2)) measurements. We obtain a spectral purity of 0.91 and coupling efficiencies around 90% for all four photons without any filtering. These pure indistinguishable photon sources at telecom wavelengths are perfectly adapted for quantum network demonstrations and other multi-photon protocols.

Interaction of independent single photons based on integrated nonlinear optics.

The parametric interaction of light beams in nonlinear materials is usually thought to be too weak to be observed when the fields involved are at the single-photon level. However, such single-photon level nonlinearity is not only fundamentally fascinating but holds great potential for emerging technologies and applications involving heralding entanglement at a distance. Here we use a high-efficiency waveguide to demonstrate the sum-frequency generation between a single photon and a single-photon level coherent state. The use of an integrated, solid state, room temperature device and telecom wavelengths makes this type of system directly applicable to future quantum communication technologies such as device-independent quantum key distribution.

High efficiency coupling of photon pairs in practice.

Multi-photon and quantum communication experiments such as loophole-free Bell tests and device independent quantum key distribution require entangled photon sources which display high coupling efficiency. In this paper we put forward a simple quantum theoretical model which allows the experimenter to design a source with high pair coupling efficiency. In particular we apply this approach to a situation where high coupling has not been previously obtained: we demonstrate a symmetric coupling efficiency of more than 80% in a highly frequency non-degenerate configuration. Furthermore, we demonstrate this technique in a broad range of configurations, i.e. in continuous wave and pulsed pump regimes, and for different nonlinear crystals.

[Epidemiological surveillance of patients treated with digoxin]. / Aportes en la vigilancia epidemiológica de los pacientes tratados con digoxina.

In the present study we assess that the etiology of digitalis intoxication. We try to identify factors and intensity of each association. One thousand fifty patients form Havana City, Cuba were selected, under digitalis therapy. Two groups were made Cases and Controls. Each patient was evaluated by direct interview. There was a significative association (P < 0.01) among digitalis intoxication and; older persons who use high doses of digoxin, other risk factors were underweight, lack of potassium supplement, some associated diseases, combination therapy between digoxin, and furosemide, thyazides, dipyridamole, amiodarone, quinidine, nifedipine or verapamil, cigar smoking, alcohol intake and prior history of digitalis intoxication. The odds ratio (OR) was calculated for each association. We conclude: some factors are responsible for digitalis intoxication, each one contribute partially.