Theoretical and experimental comprehensive study of GHz-range passively mode-locked fiber lasers.

In this paper, we present a theoretical model based on the nonlinear Schrödinger equation to characterize GHz-range passively mode-locked fiber lasers. The modeled cavities of the lasers are configured by a highly doped and polarization-maintaining single fiber of a single type. For different pulse repetition rates, ranging from 1.0 to 10.0 GHz, gain parameters and pump threshold for a stable mode-locked laser emission are studied. Pulse time width, spectral width, and semiconductor saturable absorber mirror (SESAM) properties are defined to achieve stable emission. To experimentally validate our theoretical model, 1.0 and 2.2 GHz laser cavities have been built up and amplified. A stable and robust operation for both frequencies was obtained, and the experimental measurements have been found to match the theoretical predictions. Finally, enhanced environmental stability has been achieved using a cavity temperature control system and an antivibration enclosure.

Relación entre exposición a corto plazo a dióxido de azufre atmosférico y lesiones obstructivas en el síndrome coronario agudo / Relationship between short-term exposure to atmospheric sulfur dioxide and obstructive lesions in acute coronary syndrome

Fundamentos y objetivo: Los contaminantes del aire urbano están constituidos por una mezcla heterogénea de sustancias presentes en estado gaseoso y aerosoles. El objetivo del presente estudio fue comparar los efectos causados por la exposición a contaminantes en fase gas y partículas atmosféricas en aire ambiente en pacientes que ingresan por un síndrome coronario agudo (SCA), en relación con la presencia o no de lesiones obstructivas significativas (LOS) en arterias coronarias epicárdicas. Pacientes y método: Analizamos de forma prospectiva a un total de 2.110 pacientes con el diagnóstico de SCA. Se determinaron las concentraciones medias de contaminantes en fase gas y partículas atmosféricas desde el día anterior hasta 7 días previos al ingreso. Se dividió la población de estudio en aquellos con presencia o no de LOS. Resultados: De los 2.110 pacientes con SCA, 1.892 presentaban LOS y 218 no. Cuando se compararon las concentraciones de los contaminantes en fase gas, se observó que, en los pacientes con LOS, el dióxido de azufre tenía una tendencia a tener valores más altos (media [DE] de 10,93 [9,31] frente a 8,33 [6,77] ¿g/m; p=0,004). El análisis multivariable muestra que por cada 10¿g/m3 de aumento del dióxido de azufre, aumenta el riesgo de ingreso por SCA con LOS frente a sin LOS un 41% (odds ratio 1,41; intervalo de confianza del 95% 1,039-1,931; p=0,028). Conclusiones: En nuestra población de estudio, la exposición a concentraciones elevadas de dióxido de azufre constituyen un factor precipitante de ingreso para pacientes con SCA y LOS (AU)

Background and objectives: Urban air pollutants are composed of a heterogeneous mixture of substances in gas and aerosol states. The aim of this study was to compare the effects caused by exposure to contaminants in the gas phase and atmospheric particles in ambient air in patients hospitalized for acute coronary syndrome (ACS) regarding the presence or absence of significant obstructive lesions (SOL) in epicardial coronary arteries. Patients and methods: Prospectively analyzed a total of 2,110 patients with a diagnosis of ACS. We determined the mean concentrations of contaminants in the gas phase and atmospheric particles from the day before until 7 days prior to admission (1 to 7 days lag time). We divided the study population into those with presence or absence of SOL. Results: Of the 2,110 patients with ACS, 1,892 presented SOL and 218 without SOL. When comparing the concentrations of contaminants in the gas phase, we observed that the sulfur dioxide in patients with SOL had a trend toward higher values (10.93±8.33 versus 9.31±6.77¿g/m3; P=.004). Multivariate analysis shows that for every 10¿g/m3 increase of sulfur dioxide, there is an increase in the risk of hospitalization for ACS with SOL a 41% (odds ratio 1.41; 95% confidence interval 1.039-1.931; P=.028). Conclusions: In our study population, exposure to high concentrations of sulfur dioxide is a precipitating factor for admission of patients with ACS and SOL (AU)

Air pollution and heart failure: Relationship with the ejection fraction.

AIM: To study whether the concentrations of particulate matter in ambient air are associated with hospital admission due to heart failure in patients with heart failure with preserved ejection fraction and reduced ejection fraction. METHODS: We studied 353 consecutive patients admitted into a tertiary care hospital with a diagnosis of heart failure. Patients with ejection fraction of ≥ 45% were classified as having heart failure with preserved ejection fraction and those with an ejection fraction of < 45% were classified as having heart failure with reduced ejection fraction. We determined the average concentrations of different sizes of particulate matter (< 10, < 2.5, and < 1 µm) and the concentrations of gaseous pollutants (carbon monoxide, sulphur dioxide, nitrogen dioxide and ozone) from 1 d up to 7 d prior to admission. RESULTS: The heart failure with preserved ejection fraction population was exposed to higher nitrogen dioxide concentrations compared to the heart failure with reduced ejection fraction population (12.95 ± 8.22 µg/m(3) vs 4.50 ± 2.34 µg/m(3), P < 0.0001). Multivariate analysis showed that nitrogen dioxide was a significant predictor of heart failure with preserved ejection fraction (odds ratio ranging from (1.403, 95%CI: 1.003-2.007, P = 0.04) to (1.669, 95%CI: 1.043-2.671, P = 0.03). CONCLUSION: This study demonstrates that short-term nitrogen dioxide exposure is independently associated with admission in the heart failure with preserved ejection fraction population.

[Relationship between short-term exposure to atmospheric sulfur dioxide and obstructive lesions in acute coronary syndrome]. / Relación entre exposición a corto plazo a dióxido de azufre atmosférico y lesiones obstructivas en el síndrome coronario agudo.

BACKGROUND AND OBJECTIVES: Urban air pollutants are composed of a heterogeneous mixture of substances in gas and aerosol states. The aim of this study was to compare the effects caused by exposure to contaminants in the gas phase and atmospheric particles in ambient air in patients hospitalized for acute coronary syndrome (ACS) regarding the presence or absence of significant obstructive lesions (SOL) in epicardial coronary arteries. PATIENTS AND METHODS: Prospectively analyzed a total of 2,110 patients with a diagnosis of ACS. We determined the mean concentrations of contaminants in the gas phase and atmospheric particles from the day before until 7 days prior to admission (1 to 7 days lag time). We divided the study population into those with presence or absence of SOL. RESULTS: Of the 2,110 patients with ACS, 1,892 presented SOL and 218 without SOL. When comparing the concentrations of contaminants in the gas phase, we observed that the sulfur dioxide in patients with SOL had a trend toward higher values (10.93 ± 8.33 versus 9.31 ± 6.77 µg/m(3); P = .004). Multivariate analysis shows that for every 10 µg/m(3) increase of sulfur dioxide, there is an increase in the risk of hospitalization for ACS with SOL a 41% (odds ratio 1.41; 95% confidence interval 1.039-1.931; P = .028). CONCLUSIONS: In our study population, exposure to high concentrations of sulfur dioxide is a precipitating factor for admission of patients with ACS and SOL.

Alignment-free, all-spliced fiber laser source for CARS microscopy based on four-wave-mixing.

An environmentally-stable low-repetition rate fiber oscillator is developed to produce narrow-bandwidth pulses with several tens of picoseconds duration. Based on this oscillator an alignment-free all-fiber laser for multi-photon microscopy is realized using in-fiber frequency conversion based on four-wave-mixing. Both pump and Stokes pulses for coherent anti-Stokes Raman scattering (CARS) microscopy are readily available from one fiber end, intrinsically overlapped in space and time, which drastically simplifies the experimental handling for the user. The complete laser setup is mounted on a home-built laser scanning microscope with small footprint. High-quality multimodal microscope images of biological tissue are presented probing the CH-stretching resonance of lipids at an anti-Stokes Raman-shift of 2845 cm(-1) and second-harmonic generation of collagen. Due to its simplicity, compactness, maintenance-free operation, and ease-of-use the presented low-cost laser is an ideal source for bio-medical applications outside laser laboratories and in particular inside clinics.

Estudio comparativo de las partículas en aire ambiente en pacientes ingresados por insuficiencia cardiaca y síndrome coronario agudo / Comparative study of ambient air particles in patients hospitalized for heart failure and acute coronary syndrome

Introducción y objetivos: Actualmente se considera la contaminación atmosférica como un factor de riesgo emergente de enfermedades cardiovasculares. Nuestro objetivo fue comparar las concentraciones de partículas atmosféricas en aire ambiente y analizar su relación con los factores de riesgo cardiovascular en pacientes que ingresan en un servicio de cardiología de un hospital terciario con el diagnóstico de insuficiencia cardiaca y síndrome coronario agudo (SCA). Métodos: Analizamos a un total de 3.950 pacientes ingresados de forma consecutiva con el diagnóstico de insuficiencia cardiaca y SCA. Se determinaron las concentraciones medias de material particulado con tamaño < 10, 2,5 y 1μm y partículas ultrafinas, desde el día anterior hasta los 7 días previos al ingreso (1 a 7 días de retardo). Resultados: No se observaron diferencias estadísticamente significativas en las concentraciones medias de material particulado con tamaño < 10, 2,5 y 1μm en ambos grupos de población. Cuando se compararon las concentraciones de partículas ultrafinas de los pacientes ingresados por insuficiencia cardiaca y SCA, se observó que los primeros tenían tendencia a valores más altos (19.845,35±8.806,49 frente a 16.854,97±8.005,54/cm−3; p<0 001 el análisis multivariable muestra que las partículas ultrafinas son un factor de riesgo para ingresar por insuficiencia cardiaca tras controlar los distintos factores cardiovascular odds ratio=1,4; intervalo de confianza del 95%, 1,15-1,66; p=0,02). Conclusiones: En nuestra población de estudio, comparada con pacientes con SCA, la exposición a partículas ultrafinas constituye un factor precipitante del ingreso por insuficiencia cardiaca (AU)

Introduction and objectives: Currently air pollution is considered as an emerging risk factor for cardiovascular disease. Our objective was to study the concentrations of particulate matter in ambient air and analyze their relationship with cardiovascular risk factors in patients admitted to a cardiology department of a tertiary hospital with the diagnosis of heart failure or acute coronary syndrome (ACS). Methods: We analyzed 3950 consecutive patients admitted with the diagnosis of heart failure or ACS. We determined the average concentrations of different sizes of particulate matter (<10 2 5 and <1 956 m and ultrafine particles from 1 day or up to 7 days prior admission lag time Results: There were no statistically significant differences in mean concentrations of particulate matter <10 2 5 and <1 956 m in size both populations when comparing the concentrations of ultrafine particles patients admitted due to heart failure and acute coronary syndrome it was observed that former had a tendency have higher values 19 845 35 8 806 49 vs 16 854 97 8005 54cm −3, P <.001). The multivariate analysis showed that ultrafine particles are a risk factor for admission for heart failure, after controlling for other cardiovascular risk factors (odds ratio=1.4; confidence interval 95%, from 1.15 to 1.66 P=.02). Conclusions: In our study population, compared with patients with ACS, exposure to ultrafine particles is a precipitating factor for admission for heart failure (AU)

Comparative study of ambient air particles in patients hospitalized for heart failure and acute coronary syndrome.

INTRODUCTION AND OBJECTIVES: Currently air pollution is considered as an emerging risk factor for cardiovascular disease. Our objective was to study the concentrations of particulate matter in ambient air and analyze their relationship with cardiovascular risk factors in patients admitted to a cardiology department of a tertiary hospital with the diagnosis of heart failure or acute coronary syndrome (ACS). METHODS: We analyzed 3950 consecutive patients admitted with the diagnosis of heart failure or ACS. We determined the average concentrations of different sizes of particulate matter (<10, <2.5, and <1 µm and ultrafine particles) from 1 day or up to 7 days prior to admission (1 to 7 days lag time). RESULTS: There were no statistically significant differences in mean concentrations of particulate matter <10, <2.5 and <1 µm in size in both populations. When comparing the concentrations of ultrafine particles of patients admitted due to heart failure and acute coronary syndrome, it was observed that the former had a tendency to have higher values (19 845.35 ± 8 806.49 vs 16 854.97 ± 8005.54 cm⁻³, P <.001). The multivariate analysis showed that ultrafine particles are a risk factor for admission for heart failure, after controlling for other cardiovascular risk factors (odds ratio=1.4; confidence interval 95%, from 1.15 to 1.66 P=.02). CONCLUSIONS: In our study population, compared with patients with ACS, exposure to ultrafine particles is a precipitating factor for admission for heart failure.