1,698 research outputs found
Double resonance of Raman transitions in a degenerate Fermi gas
We measure momentum-resolved Raman spectra of a spin-polarized degenerate
Fermi gas of Yb atoms for a wide range of magnetic fields, where the
atoms are irradiated by a pair of counterpropagating Raman laser beams as in
the conventional spin-orbit coupling scheme. Double resonance of first- and
second-order Raman transitions occurs at a certain magnetic field and the
spectrum exhibits a doublet splitting for high laser intensities. The measured
spectral splitting is quantitatively accounted for by the Autler-Townes effect.
We show that our measurement results are consistent with the spinful band
structure of a Fermi gas in the spatially oscillating effective magnetic field
generated by the Raman laser fields.Comment: 7 pages, 6 figure
Diseño y desarrollo de un sistema para la visualización de parámetros bioenergéticos: ritmo cardiaco, cuenta pasos y calorías
Debido a la gran problemática que existe actualmente en el Perú y el mundo con
respecto a la inactividad física, se desarrolló un dispositivo portátil capaz de mostrar
algunos parámetros bioenergéticos como ritmo cardiaco, zona de entrenamiento y
calorías consumidas. Su objetivo es brindar un apoyo a las personas que requieren
ejercitarse de una forma específica; como las personas con sobrepeso que
requieren reducir la grasa corporal, los pacientes cardiacos que no deben
sobrepasar cierta frecuencia cardiaca y los adultos mayores que no deben perder
su capacidad motora. El dispositivo desarrollado tiene la capacidad de calcular los
parámetros antes mencionados gracias a que combina las características de un
podómetro y un medidor de ritmo cardiaco. Cabe mencionar que actualmente no
existe algún aparato con tales prestaciones.
El dispositivo consta de un sistema de adquisición, un sistema de control y un
sistema de visualización. En el sistema de adquisición, un sensor de aceleración se
encarga de captar la señal para el podómetro y tres electrodos se encargan de
captar la señal del corazón. Ambas señales son acondicionadas antes de pasar al
sistema de control donde un microprocesador las evalúa y realiza los algoritmos
respectivos para calcular los parámetros bioenergéticos. Por último, el sistema de
visualización es el encargado de mostrar dichos parámetros al usuario.
Es necesario añadir que para calcular los parámetros con mayor precisión, se
utilizan algunos datos ingresados por el usuario, tales como su edad, su peso y su
longitud de zancada.
Según las pruebas realizadas, se logró obtener margen de error menor al 3%,
cumpliendo así con el objetivo de precisión propuesto. Se espera que en un futuro
sea implementado y utilizado por las personas.Tesi
Vertically aligned InGaN nanowires with engineered axial In composition for highly efficient visible light emission.
We report on the fabrication of novel InGaN nanowires (NWs) with improved crystalline quality and high radiative efficiency for applications as nanoscale visible light emitters. Pristine InGaN NWs grown under a uniform In/Ga molar flow ratio (UIF) exhibited multi-peak white-like emission and a high density of dislocation-like defects. A phase separation and broad emission with non-uniform luminescent clusters were also observed for a single UIF NW investigated by spatially resolved cathodoluminescence. Hence, we proposed a simple approach based on engineering the axial In content by increasing the In/Ga molar flow ratio at the end of NW growth. This new approach yielded samples with a high luminescence intensity, a narrow emission spectrum, and enhanced crystalline quality. Using time-resolved photoluminescence spectroscopy, the UIF NWs exhibited a long radiative recombination time (τr) and low internal quantum efficiency (IQE) due to strong exciton localization and carrier trapping in defect states. In contrast, NWs with engineered In content demonstrated three times higher IQE and a much shorter τr due to mitigated In fluctuation and improved crystal quality
Analysis of Initial Baseline Clinical Parameters and Treatment Strategy Associated with Medication Failure in the Treatment of Benign Prostatic Hyperplasia in Korea
Purpose To analyze the baseline clinical factors and medication treatment strategy used in cases with medication treatment failure of benign prostatic hyperplasia (BPH). Methods From January 2006 to December 2009, 677 BPH patients with at least 3 months of treatment with medication were enrolled. We analyzed clinical factors by medication failure (n=161) versus maintenance (n=516), by prostate size (less than 30 g, n=231; 30 to 50 g, n=244; greater than 50 g, n=202), and by prostate-specific antigen (PSA) levels (less than 1.4 ng/mL, n=324; more than 1.4 ng/mL, n=353). Results Age, combination medication rate, PSA, and prostate volume were statistically different between the medication treatment failure and maintenance groups. By prostate size, the PSA and medication failure rates were relatively higher and the medication period was shorter in patients with a prostate size of more than 30 g. The combination medication rate was higher in patients with a prostate size of more than 50 g. The medication failure rate and prostate volume were higher in patients with a PSA level of more than 1.4 ng/mL. However, the combination treatment rate was not significantly different in patients with a PSA level lower than 1.4 ng/mL. Suggestive cutoffs for combination medication are a prostate volume of 34 g and PSA level of 1.9 ng/mL. Conclusions The clinical factors associated with medication failure were age, treatment type, and prostate volume. Combination therapy should be considered more in Korea in patients with a PSA level higher than 1.4 ng/mL and a prostate volume of between 30 and 50 g to prevent medication failure
An efficient privacy protection in mobility social network services with novel clustering-based anonymization
Arterial Injury Associated with Tension-Free Vaginal Tapes-SECUR Procedure Successfully Treated by Radiological Embolization
Various postoperative complications have been reported after the use of tension-free vaginal tapes (TVT). The transobturator approach was introduced to minimize the potential complications. The next generation of recently introduced TVT-SECUR is intended to minimize the incidence of complications. Herein we report a case of internal pudendal artery injury sustained during this procedure that was successfully treated by radiological embolization. Angiography with vessel embolization, when available, should be considered when the arterial injury is suspected
The Association between Apolipoprotein A-II and Metabolic Syndrome in Korean Adults: A Comparison Study of Apolipoprotein A-I and Apolipoprotein B
BackgroundApolipoprotein A-II (apoA-II) is the second-most abundant apolipoprotein in human high-density lipoprotein and its role in cardio metabolic risk is not entirely clear. It has been suggested to have poor anti-atherogenic or even pro-atherogenic properties, but there are few studies on the possible role of apoA-II in Asian populations. The aim of this study is to evaluate the role of apoA-II in metabolic syndrome (MetS) compared with apolipoprotein A-I (apoA-I) and apolipoprotein B (apoB) in Korean adults.MethodsWe analyzed data from 244 adults who visited the Center for Health Promotion in Pusan National University Yangsan Hospital for routine health examinations.ResultsThe mean apoB level was significantly higher, and the mean apoA-I level was significantly lower, in MetS; however, there was no significant difference in apoA-II levels (30.5±4.6 mg/dL vs. 31.2±4.6 mg/dL, P=0.261). ApoA-II levels were more positively correlated with apoA-I levels than apoB levels. ApoA-II levels were less negatively correlated with homocysteine and high sensitivity C-reactive protein levels than apoA-I levels. The differences in MetS prevalence from the lowest to highest quartile of apoA-II were not significant (9.0%, 5.7%, 4.9%, and 6.6%, P=0.279). The relative risk of the highest quartile of apoA-II compared with the lowest quartile also was not significantly different (odds ratio, 0.96; 95% confidence interval, 0.95 to 1.04; P=0.956).ConclusionCompared with apoA-I (negative association with MetS) and apoB (positive association with MetS) levels, apoA-II levels did not show any association with MetS in this study involving Korean adults. However, apoA-II may have both anti-atherogenic and pro-atherogenic properties
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