Properties of a-C:H films deposited from a methane electron cyclotron wave resonant plasma

N.A.Morrison,C.William,B.Racine,W.I.Milne,E.Martinez,J.Esteve,J.L.Andujar 한국물리학회 2003 Current Applied Physics Vol.3 No.5

An electron cyclotron wave resonant methane plasma discharge was used for the high rate deposition of hydrogenated amorphous carbon (a-C:H). Deposition rates of up to 400 AA/min were obtained over substrates up to 2.5 in. in diameter with a film thickness uniformity of 10%. The deposited films were characterised in terms of their mass density, sp3 and hydrogen contents, C–H bonding, intrinsic stress, scratch resistance and friction properties. The deposited films possessed an average sp3 content, mass density and refractive index of 58%, 1.76 g/cm3 and 2.035 respectively. Mechanical characterisation indicated that the films possessed very low steady-state coefficients of friction (ca. 0.06) and a moderate shear strength of 141 MPa. Nano-indentation measurements also indicated a hardness and elastic modulus of 16.1 and 160 GPa respectively. The critical loads required to induce coating failure were also observed to increase with ion energy as a consequence of the increase in degree of ion mixing at the interface. Furthermore, coating failure under scratch test conditions was observed to take place via fracture within the silicon substrate itself, rather than either in the coating or at the film/substrate interface. 2003 Elsevier B.V. All rights reserved.

The Effect of Agave tequilana Weber Inulin on Postprandial Ghrelin Concentration in Obese Patients

Betsabe Contreras-Haro,Jose A. Robles-Cervantes,Manuel Gonzalez-Ortiz,Esperanza Martinez-Abundis,Claudia Espinel-Bermudez,Martha P. Gallegos-Arreola,Karina C. Morgado-Castillo 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.2

This study was performed to investigate the effect of Agave tequilana Weber inulin on postprandial ghrelin levels in obese patients. A randomized, double-blind, cross-over design was performed. A total of 14 patients were allocated into two groups: one group received a drink that contained 500 mL lemon water, 24 g of A. tequilana Weber inulin, and 75 g glucose and the other group received a placebo drink with 500 mL lemon drink and 75 g of glucose. After a 7-day washout period, the groups were crossed. The primary outcome measure was postprandial ghrelin levels between minute 240 and minute 270. A. tequilana Weber inulin did not change postprandial ghrelin concentration in obese patients.

A New Approach to Receding Horizon State Estimation for LTI Systems in the Presence of Non-uniform Sampled Measurements

Jhon A. Isaza-Hurtado,John J. Martinez,Hector A. Botero-Castro 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.3

This paper proposes a recursive solution as an estimation strategy that incorporates non-uniform sampledmeasurements for a Linear Time-Invariant (LTI) Systems. The estimator is based on a modified Receding HorizonEstimator. The proposed approach allows system states to be recursively estimated, reducing estimation error byincluding measurements available at different sampling times, using a well-known structure. A discussion of theobservability of the system in the presence of non-uniform measurements and the convergence conditions of theproposed estimator are also presented. Finally, numerical simulation demonstrates the effectiveness of the proposedestimator in comparison with a method using a Kalman filter with augmented state widely reported in the literature.

Matrices similar to centrosymmetric matrices

Benjamin A. Itza-Ortiz,Ruben A. Martinez-Avendano 대한수학회 2022 대한수학회지 Vol.59 No.5

In this paper we give conditions on a matrix which guarantee that it is similar to a centrosymmetric matrix. We use this conditions to show that some $4 \times 4$ and $6 \times 6$ Toeplitz matrices are similar to centrosymmetric matrices. Furthermore, we give conditions for a matrix to be similar to a matrix which has a centrosymmetric principal submatrix, and conditions under which a matrix can be dilated to a matrix similar to a centrosymmetric matrix.

GP3 is a structural component of the PRRSV type II (US) virion

de Lima, M.,Ansari, I.H.,Das, P.B.,Ku, B.J.,Martinez-Lobo, F.J.,Pattnaik, A.K.,Osorio, F.A. Academic Press 2009 Virology Vol.390 No.1

Glycoprotein 3 (GP3) is a highly glycosylated PRRSV envelope protein which has been reported as being present in the virions of PRRSV type I, while missing in the type II PRRSV (US) virions. We herein present evidence that GP3 is indeed incorporated in the virus particles of a North American strain of PRRSV (FL12), at a density that is consistent with the minor structural role assigned to GP3 in members of the Arterivirus genus. Two 15aa peptides corresponding to two different immunodominant linear epitopes of GP3 derived from the North American strain of PRRSV (FL12) were used as antigen to generate a rabbit monospecific antiserum to this protein. The specificity of this anti-GP3 antiserum was confirmed by radioimmunoprecipitation (RIP) assay using BHK-21 cells transfected with GP3 expressing plasmid, MARC-145 cells infected with FL12 PRRSV, as well as by confocal microscopy on PRRSV-infected MARC-145 cells. To test if GP3 is a structural component of the virion, <SUP>35</SUP>S-labelled PRRSV virions were pelleted through a 30% sucrose cushion, followed by a second round of purification on a sucrose gradient (20-60%). Virions were detected in specific gradient fractions by radioactive counts and further confirmed by viral infectivity assay in MARC 145 cells. The GP3 was detected in gradient fractions containing purified virions by RIP using anti-GP3 antiserum. Predictably, the GP3 was less abundant in purified virions than other major structural envelope proteins such as GP5 and M. Further evidence of the presence of GP3 at the level of PRRSV FL12 envelope was obtained by immunogold staining of purified virions from the supernatant of infected cells with anti-GP3 antiserum. Taken together, these results indicate that GP3 is a minor structural component of the PRRSV type II (FL12 strain) virion, as had been previously described for PRRSV type I.

Nutraceutical emulsion containing valproic acid (NE-VPA): a drug delivery system for reversion of seizures in zebrafish larvae epilepsy model

Daniela Agustina Feas,Daniela Edith Igartúa,María Natalia Calienni,Carolina Soledad Martinez,Marina Pifano,Nadia Silvia Chiaramoni,Silvia del Valle Alonso,María Jimena Prieto 한국약제학회 2017 Journal of Pharmaceutical Investigation Vol.47 No.5

Valproic acid (VPA) is an antiepileptic drug, which is currently used in neurodegenerative diseases. However, a high dose is required to obtain a therapeutic effect. Long-chain polyunsaturated fatty acids (PUFAs), such as omega 3 and omega 6, are efficient complements in treatments for neurological diseases. Previous studies have reported that a dietary supplement containing PUFAs together with the administration of antiepileptic drugs significantly reduces the frequency of seizures. Based on this, the main goal of this work was to obtain a complex based on VPA encapsulation in an oil/water (o/w) nutraceutical emulsion (NE) enriched with PUFAs for oral administration. Besides, encapsulation of VPA might reduce its dose and increase its therapeutic effect. In order to study its effect, we used a zebrafish larvae model of induced epileptiform behavior with the proconvulsant drug pentylenetetrazol (PTZ). Results have shown that when 100 μM VPA and fatty acids were combined in the NE (NE-VPA), the epileptiform behavior of PTZ-treated zebrafish larvae decreased significantly. Additionally, morphological changes, hepatotoxicity, lethality and heart rate were studied. Despite the fact that a high dose of VPA exerted a cardiotoxic effect, this was no longer detected after addition of this drug in the NE. This treatment exerted a significant antiepileptic effect and did not result in highly toxic or lethal effects. In order to develop an improved pharmaceutical treatment, and considering that all the components used are FDA approved for consumption, the NE-VPA selected might be easily incorporated into clinical trials.

Safety of Nonoperative Management After Acute Diverticulitis

Javier Suarez Alecha,Sonia Amoza Pais,Xavi Batlle Marin,Begoña Oronoz Martinez,Enrique Balen Ribera,Concepción Yarnoz Irazabal 대한대장항문학회 2014 Annals of Coloproctolgy Vol.30 No.5

Purpose: The role of surgery in the management of diverticular disease after an episode of acute diverticulitis (AD) managed in a conservative form is evolving. Age, number of episodes of AD, type of episode, and symptoms after the episodes are factors related to the need for elective surgery. The aim of this study is to evaluate the safety of conservative management and the risk factors for emergency surgery after a first episode of AD managed without surgery. Methods: We retrospectively evaluated 405 patients diagnosed as having had a first episode of AD. Sixty-nine patients underwent emergency surgery on the first admission, and 69 patients had an elective operation in the follow-up (group A). The remaining 267 patients were managed initially without surgery (group B). Thirteen of these 267 patients needed a further urgent surgical procedure. Factors involved in the decision of elective surgery and the probability of emergency surgery after the first episode of AD managed without surgery were evaluated in relation to demographic factors, risk factors, presence of recurrences, and type of the first episode. Results: Patients, mean age was 62.7 years, 71 were aged less than 51, and 151 were males. The mean follow-up for patients with nonoperative management was 91.2 months. An elective operation was performed in 69 patients. Compared to patients in group B, those in group A more frequently had a first episode of complicated acute diverticulitis (CAD) (37.1% vs. 16.4%; P = 0.000) and were more likely to be smokers (46.3% vs. 19.3%; P = 0.000) and to suffer more than one episode of AD (42% vs. 26.9%; P = 0.027). Nonoperative management was chosen for 267 patients, but 13 patients needed an emergency operation later. In the multivariate analysis, we found a significant relation between the presence of CAD in the first episode and the need for emergency surgery. There were no differences in surgical mortality between the patients in the two groups, but patients treated with elective surgery had a higher rate of stoma than patients treated non-operatively (7.2% vs. 1.4%; P = 0.028); this difference was not observed in the subgroup of patients with CAD (15.3% vs. 6.8%; P = 0.458). Conclusion: After an episode of AD, nonoperative management is safe because fewer than 5% of patients will need an emergent procedure in a subsequent attack of AD. A first episode of CAD is the only risk factor for emergency surgery in patients managed conservatively.

Autorotation of square plates, with application to windborne debris

Martinez-Vazquez, P.,Sterling, M.,Baker, C.J.,Quinn, A.D.,Richards, P.J. Techno-Press 2011 Wind and Structures, An International Journal (WAS Vol.14 No.2

This paper presents the results of measurements relating to the aerodynamic forces on flat square plates which were allowed to rotate at different speeds about their horizontal axis, by modifying the velocity of the incoming flow. A 1 m square test-sheet and a 0.3 m square test-sheet were fitted with a number of pressure sensors in order to obtain information relating to the instantaneous pressure distribution acting on the test-sheet; a compact gyroscope to record the angular velocity during the rotational motion was also implemented. Previous work on autorotation has illustrated that the angular velocity varies with respect to the torque induced by the wind, the thickness and aspect ratio of the test-sheet, any frictional effects present at the bearings, and the vorticity generated through the interaction between the plate and the wind flow. The current paper sets out a method based on the solution of the equation of motion of a rotating plate which enables the determination of angular velocities on autorotating elements to be predicted. This approach is then used in conjunction with the experimental data in order to evaluate the damping introduced by the frictional effects at the bearings during steady autorotation.

Effect of Serve Execution on Serve Efficacy in Men`s and Women`s Beach Volleyball

( A. B. Lopez Martinez ),( J. M. Palao ) 한국스포츠정책과학원(구 한국스포츠개발원) 2009 International Journal of Applied Sports Sciences Vol.21 No.1

The purpose of this study was to assess the effect of serve technique and its manner of execution on the efficacy of the serve in beach volleyball according to gender. A total of 1073 serves from 25 sets of the 2003 World Championship and the 2004 Olympic Games were analyzed (508 serves from men`s games and 576 serves from women`s games). The variables studied were: type of serve (standing serve or jump serve), manner of execution (origin, destination, and distance), serve efficacy, result of the action, and gender. Descriptive and inferential analyses of the data were done (chi-square test and likelihood ratio) with a level of statistical significance set at p<0.05. The results show that for both genders: a) the jump serve involved a higher number of errors, points, and actions that limited the opponent; b) the jump serve and standing serve involved similar levels of efficacy; c) the serve directed toward the interference zone between receivers was the most effective; d) players used the jump serve and the standing serve; and e) no relationship was found between type of serve and result of the rally.

Aerodynamic forces on fixed and rotating plates

Martinez-Vazquez, P.,Baker, C.J.,Sterling, M.,Quinn, A.,Richards, P.J. Techno-Press 2010 Wind and Structures, An International Journal (WAS Vol.13 No.2

Pressure measurements on static and autorotating flat plates have been recently reported by Lin et al. (2006), Holmes, et al. (2006), and Richards, et al. (2008), amongst others. In general, the variation of the normal force with respect to the angle of attack appears to stall in the mid attack angle range with a large scale separation in the wake. To date however, no surface pressures have been measured on auto-rotating plates that are typical of a certain class of debris. This paper presents the results of an experiment to measure the aerodynamic forces on a flat plate held stationary at different angles to the flow and allowing the plate to auto-rotate. The forces were determined through the measurement of differential pressures on either side of the plate with internally mounted pressure transducers and data logging systems. Results are presented for surface pressure distributions and overall integrated forces and moments on the plates in coefficient form. Computed static force coefficients show the stall effect at the mid range angle of attack and some variation for different Reynolds numbers. Normal forces determined from autorotational experiments are higher than the static values at most pitch angles over a cycle. The resulting moment coefficient does not compare well with current analytical formulations which suggest the existence of a flow mechanism that cannot be completely described through static tests.