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1.
PLoS One ; 11(9): e0163034, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27654703

RESUMO

This paper presents an experimental characterization of millimeter-wave (mm-wave) channels in the 6.5 GHz, 10.5 GHz, 15 GHz, 19 GHz, 28 GHz and 38 GHz frequency bands in an indoor corridor environment. More than 4,000 power delay profiles were measured across the bands using an omnidirectional transmitter antenna and a highly directional horn receiver antenna for both co- and cross-polarized antenna configurations. This paper develops a new path-loss model to account for the frequency attenuation with distance, which we term the frequency attenuation (FA) path-loss model and introduce a frequency-dependent attenuation factor. The large-scale path loss was characterized based on both new and well-known path-loss models. A general and less complex method is also proposed to estimate the cross-polarization discrimination (XPD) factor of close-in reference distance with the XPD (CIX) and ABG with the XPD (ABGX) path-loss models to avoid the computational complexity of minimum mean square error (MMSE) approach. Moreover, small-scale parameters such as root mean square (RMS) delay spread, mean excess (MN-EX) delay, dispersion factors and maximum excess (MAX-EX) delay parameters were used to characterize the multipath channel dispersion. Multiple statistical distributions for RMS delay spread were also investigated. The results show that our proposed models are simpler and more physically-based than other well-known models. The path-loss exponents for all studied models are smaller than that of the free-space model by values in the range of 0.1 to 1.4 for all measured frequencies. The RMS delay spread values varied between 0.2 ns and 13.8 ns, and the dispersion factor values were less than 1 for all measured frequencies. The exponential and Weibull probability distribution models best fit the RMS delay spread empirical distribution for all of the measured frequencies in all scenarios.

2.
PLoS One ; 11(5): e0155077, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27152423

RESUMO

As the enterprise of the "Internet of Things" is rapidly gaining widespread acceptance, sensors are being deployed in an unrestrained manner around the world to make efficient use of this new technological evolution. A recent survey has shown that sensor deployments over the past decade have increased significantly and has predicted an upsurge in the future growth rate. In health-care services, for instance, sensors are used as a key technology to enable Internet of Things oriented health-care monitoring systems. In this paper, we have proposed a two-stage fundamental approach to facilitate the implementation of such a system. In the first stage, sensors promptly gather together the particle measurements of an android application. Then, in the second stage, the collected data are sent over a Femto-LTE network following a new scheduling technique. The proposed scheduling strategy is used to send the data according to the application's priority. The efficiency of the proposed technique is demonstrated by comparing it with that of well-known algorithms, namely, proportional fairness and exponential proportional fairness.


Assuntos
Internet , Monitorização Fisiológica/métodos , Algoritmos , Humanos , Aplicativos Móveis
3.
Med Princ Pract ; 13(2): 107-10, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14755144

RESUMO

OBJECTIVES: To report a case of perinatal tuberculosis that appeared on the 21st day of life of an infant born to a mother with latent tuberculosis. CLINICAL PRESENTATION AND INTERVENTION: A preterm male infant was born by spontaneous vertex delivery at 33 weeks gestational age to a 33-year-old primiparous Philippine woman. The infant was well until the 21st day of life when he developed recurrent episodes of cyanosis and bradycardia. A chest radiograph showed infiltrates which were thought to be bacterial in origin. Blood, urine, and cerebrospinal fluid cultures were normal. Tracheal aspirate revealed acid-fast bacilli by Ziehl-Neelsen stain, later confirmed to be MYCOBACTERIUM TUBERCULOSIS by culture in Lowenstein-Jensen medium. The mother was later diagnosed as a case of tuberculosis with symptoms, signs and radiologic manifestation of hilar lymphadenopathy with mild pleural effusion and positive tuberculin skin test. Both infant and mother were treated with intravenous isoniazid, intravenous rifampicin, oral pyrazinamide, and intravenous pyridoxine. Both recovered. CONCLUSION: A preterm male infant perinatally acquired tuberculosis, most likely by inhalation of the bacteria during delivery. Both infant and mother responded well to antituberculous treatment.


Assuntos
Tuberculose/diagnóstico , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Kuweit , Masculino , Tuberculose/transmissão
4.
Arch Pharm Res ; 20(6): 620-8, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18982269

RESUMO

6-Aryl-5-cyano-4-pyrimidinon-2-thione derivatives1a-c reacted with ethyl iodide to give the corresponded 2-S-ethylpyrimidin-4-one derivatives2a-c. Compounds2a-c was, in turn, reacted with hydrazine hydrate to give the sulfur free reaction products,3a-c. These reaction products were taken as the starting materials for the synthesis of several newly synthesized heterocyclic derivatives. Reactions with several halogenated ketones, esters, chloroacetic acid and chloroacetamide give pyrimidotriazines8, 12 and15 while their reactions with formic acid, acetic acid and carbon disulfide gave the corresponded triazolopyrimidines17 and21. The reaction with both acetyl acetone and ethylacetoacetate gave the corresponded 2-(3', 5'-dimethyl-1'-pyrazoly) pyrimidine derivatives20a-c and24a-c respectively while the reaction with cinnamonitriles25a-h afforded the corresponded aryl hydrazopyrimidines27a-f. The structures of these reaction products were established based on both elemental analyses and spectral data studies.

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