• Title/Summary/Keyword: Lopez

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Calculation of kinetic parameters βeff and L with modified open source Monte Carlo code OpenMC(TD)

  • Romero-Barrientos, J.;Dami, J.I. Marquez;Molina F.;Zambra, M.;Aguilera, P.;Lopez-Usquiano, F.;Parra, B.;Ruiz, A.
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.811-816
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    • 2022
  • This work presents the methodology used to expand the capabilities of the Monte Carlo code OpenMC for the calculation of reactor kinetic parameters: effective delayed neutron fraction βeff and neutron generation time L. The modified code, OpenMC(Time-Dependent) or OpenMC(TD), was then used to calculate the effective delayed neutron fraction by using the prompt method, while the neutron generation time was estimated using the pulsed method, fitting Λ to the decay of the neutron population. OpenMC(TD) is intended to serve as an alternative for the estimation of kinetic parameters when licensed codes are not available. The results obtained are compared to experimental data and MCNP calculated values for 18 benchmark configurations.

An unusual presentation of peripheral ameloblastoma in the maxilla

  • Rosa Maria Acevedo Ocana;Jorge Cortes-Breton Brinkmann;Carolina Valle Rodriguez;Norberto Quispe Lopez;María Isabel Sanchez Jorge
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.50 no.3
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    • pp.161-165
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    • 2024
  • Peripheral ameloblastoma (PA) is believed to be the rarest variant of ameloblastoma and only has been described in isolated case reports. PA is usually confined to the soft tissues surrounding the supporting tissues of the teeth. Although it manifests nonaggressive behavior and can be treated with complete removal by local surgical excision, long term follow up is mandatory to prevent future recurrence and possible malignant transformation.

Association of Histopathological Markers with Clinico-Pathological Factors in Mexican Women with Breast Cancer

  • Bandala, Cindy;De la Garza-Montano, Paloma;Cortes-Algara, Alfredo;Cruz-Lopez, Jaime;Dominguez-Rubio, Rene;Gonzalez-Lopez, Nelly Judith;Cardenas-Rodriguez, Noemi;Alfaro-Rodriguez, A;Salcedo, M;Floriano-Sanchez, E;Lara-Padilla, Eleazar
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8397-8403
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    • 2016
  • Background: Breast cancer (BCa) is the most common malignancy in Mexican women. A set of histopathological markers has been established to guide BCa diagnosis, prognosis and treatment. Nevertheless, in only a few Mexican health services, such as that of the Secretariat of National Defense (SEDENA for its acronym in Spanish), are these markers commonly employed for assessing BCa. The aim of this study was to explore the association of Ki67, TP53, HER2/neu, estrogenic receptors (ERs) and progesterone receptors (PRs) with BCa risk factors. Materials and Methods: Clinical histories provided background patient information. Immunohistochemical (IHC) analysis was conducted on 48 tissue samples from women diagnosed with BCa and treated with radical mastectomy. The Chi square test or Fisher exact test together with the Pearson and Spearman correlation were applied. Results: On average, patients were $58{\pm}10.4$ years old. It was most common to find invasive ductal carcinoma (95.8%), histological grade 3 (45.8%), with a poor Nottingham Prognostic Index (NPI; 80.4%). ERs and PRs were associated with smoking and alcohol consumption, metastasis at diagnosis and Ki67 expression (p<0.05). PR+ was also related to urea and ER+ (p<0.05). Ki67 was associated with TP53 and elevated triglycerides (p<0.05), and HER2/neu with ER+, the number of pregnancies and tumor size (p<0.05). TP53 was also associated with a poor NPI (p<0.05) and CD34 with smoking (p<0.05). The triple negative status (ER-/PR-/HER2/neu-) was related to smoking, alcohol consumption, exposure to biomass, number of pregnancies, metastasis and a poor NPI (p<0.05). Moreover, the luminal B subty was associated with histological type (p=0.007), tumor size (p=0.03) and high cholesterol (p=0.02). Conclusions: Ki67, TP53, HER2/neu, ER and PR proved to be related to several clinical and pathological factors. Hence, it is crucial to determine this IHC profile in women at risk for BCa. Certain associations require further study to understand physiological/biochemical/molecular processes.

Comparative study of acute in vitro and short-term in vivo triiodothyronine treatments on the contractile activity of isolated rat thoracic aortas

  • Lopez, Ruth Mery;Lopez, Jorge Skiold;Lozano, Jair;Flores, Hector;Carranza, Rosa Angelica;Franco, Antonio;Castillo, Enrique Fernando
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.4
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    • pp.339-348
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    • 2020
  • We aimed to characterize the participation of rapid non-genomic and delayed non-genomic/genomic or genomic mechanisms in vasoactive effects to triiodothyronine (T3), emphasizing functional analysis of the involvement of these mechanisms in the genesis of nitric oxide (NO) of endothelial or muscular origin. Influences of in vitro and in vivo T3 treatments on contractile and relaxant responsiveness of isolated rat aortas were studied. In vivo T3-treatment was 500 ㎍·kg-1·d-1, subcutaneous injection, for 1 (T31d) and 3 (T33d) days. In experiments with endothelium-intact aortic rings contracted with phenylephrine, increasing concentrations of T3 did not alter contractility. Likewise, in vitro T3 did not modify relaxant responses induced by acetylcholine or sodium nitroprusside (SNP) nor contractile responses elicited by phenylephrine or angiotensin II in endothelium-intact aortas. Concentration-response curves (CRCs) to acetylcholine and SNP in endothelium-intact aortic rings from T31d and T33d rats were unmodified. T33d, but not T31d, treatment diminished CRCs to phenylephrine in endothelium-intact aortic rings. CRCs to phenylephrine remained significantly depressed in both endothelium-denuded and endothelium-intact, nitric oxide synthase inhibitor-treated, aortas of T33d rats. In endothelium-denuded aortas of T33d rats, CRCs to angiotensin II, and high K+ contractures, were decreased. Thus, in vitro T3 neither modified phenylephrine-induced active tonus nor CRCs to relaxant and contractile agonists in endothelium-intact aortas, discarding rapid non-genomic actions of this hormone in smooth muscle and endothelial cells. Otherwise, T33d-treatment inhibited aortic smooth muscle capacity to contract, but not to relax, in an endothelium- and NO-independent manner. This effect may be mediated by delayed non-genomic/genomic or genomic mechanisms.

The Effect of Humble Leadership on Voice Behavior and Innovative Behavior: Focused on the Mediating Effect of Emotional Regulation (겸손리더십이 구성원의 발언행동과 혁신행동에 미치는 영향: 감성활용의 매개효과를 중심으로)

  • Kim, Jong-Kwan
    • Journal of Industrial Convergence
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    • v.20 no.3
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    • pp.1-10
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    • 2022
  • The results(Boje et al. 2004) suggest that corporate image is severely damaged due to arrogance and a sense of power among some of the executives. With the advent of the MZ generation, the humility of leaders who lead the organization becomes more and more important(Morris et al. 2005; Vera, Rodriguez-Lopez, 2004; Owens et al. 2013). This paper tried to empirically analyze the mediating effect of emotional regulation in the relationship between humble leadership, voice behavior, and innovative behavior. To this end, a survey was conducted from November to December 2021 for corporate employees in Busan, Gyeongnam, and Gyeongbuk, and was empirically analyzed through the results of a total of 145 surveys. As a result, it was verified that humble leadership had a positive(+) effect on voice behavior and innovative behavior, and the mediating effect of emotional regulation in the relationship between humble leadership and voice behavior and innovative behavior was also verified. Through this, this study expanded the scope of research by newly illuminating the relationship between humble leadership and emotional regulation, which are the core competencies of leaders, and revealing the causal relationship. In future research, we intend to explore the relationship between humble leadership and various variables and to investigate the relationship through various research methods.

Molecular epidemiology of Aleutian mink disease virus causing outbreaks in mink farms from Southwestern Europe: a retrospective study from 2012 to 2019

  • Prieto, Alberto;Fernandez-Antonio, Ricardo;Lopez-Lorenzo, Gonzalo;Diaz-Cao, Jose Manuel;Lopez-Novo, Cynthia;Remesar, Susana;Panadero, Rosario;Diaz, Pablo;Morrondo, Patrocinio;Diez-Banos, Pablo;Fernandez, Gonzalo
    • Journal of Veterinary Science
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    • v.21 no.4
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    • pp.65.1-65.13
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    • 2020
  • Background: Aleutian mink disease virus (AMDV) causes major economic losses in fur-bearing animal production. The control of most AMDV outbreaks is complex due to the difficulties of establishing the source of infection based only on the available on-farm epidemiological data. In this sense, phylogenetic analysis of the strains present in a farm may help elucidate the origin of the infection and improve the control and biosecurity measures. Objectives: This study had the following aims: characterize the AMDV strains from most outbreaks produced at Spanish farms between 2012-2019 at the molecular level, and assess the utility of the combined use of molecular and epidemiological data to track the possible routes of infection. Methods: Thirty-seven strains from 17 farms were partially sequenced for the NS1 and VP2 genes and analyzed phylogenetically with other strains described worldwide. Results: Spanish AMDV strains are clustered in four major clades that generally show a good geographical correlation, confirming that most had been established in Spain a long time ago. The combined study of phylogenetic results and epidemiological information of each farm suggests that most of the AMDV outbreaks since 2012 had been produced by within-farm reservoirs, while a few of them may have been due to the introduction of the virus through international trade. Conclusions: The combination of phylogenetic inference, together with epidemiological data, helps assess the possible origin of AMDV infections in mink farms and improving the control and prevention of this disease.

PID controller tuning of DC motor for speed control (직류모터의 속도 제어를 위한 PID 제어기 동조)

  • So Myung-Ok;Lee Yun-Hyung;Ahn Jong-Kap;Choi Woo-Chul
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.111-116
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    • 2004
  • In this paper, parameters of a given DC motor system are estimated using the model adjustment technique and the real coded genetic algorithm(RCGA) technique. A number of tuning methods, based on experience and experiment, such as Ziegler-Nichols, Cohen-Coon, IMC, L-ITAE Method have been proposed to obtain parameters for the PID controller. This paper proposes estimating parameters of PID controller using RCGA. The performance of the proposed algorithm is demonstrated through simulations and experiences.

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An Experimental Study on Fracture Energy of Plain Concrete

  • Lee, Jaeha;Lopez, Maria M.
    • International Journal of Concrete Structures and Materials
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    • v.8 no.2
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    • pp.129-139
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    • 2014
  • In this study, the concrete fracture energy was obtained using the three point notched beam test method developed by Hillerborg et al. (Cem Concr Res 6(6):773-782, 1976). A total of 12 notched concrete beams were tested under two different loading conditions: constant stroke control and constant crack mouth opening displacement (CMOD) control. Despite individual fracture energies obtained from the two different loading conditions showing some variation, the average fracture energy from both loading conditions was very similar. Furthermore, the results obtained support the idea that a far tail constant "A" could change the true fracture energy by up to 11 %, if it is calculated using CMOD instead of LVDT. The far tail constant "A" is determined using a least squares fit onto a straight line according to Elices et al. (Mater Struct 25(148):212-218, 1992) and RILEM report (2007). It was also observed that the selection of the end point can produce variations of the true fracture energy. The end point indicates the point in the experiment at which to stop. An end point of 2 mm has been recommended, however, in this study other end points were also considered. The final form of the bilinear softening curve was determined based on Elices and Guinea's methods (1992, 1994) and RILEM report (2007). This paper proposes a bilinear stress-crack opening displacement curve according to test results as well as the CEB-FIP model code.

Low-Voltage Tunable Pseudo-Differential Transconductor with High Linearity

  • Galan, Juan Antonio Gomez;Carrasco, Manuel Pedro;Pennisi, Melita;Martin, Antonio Lopez;Carvajal, Ramon Gonzalez;Ramirez-Angulo, Jaime
    • ETRI Journal
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    • v.31 no.5
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    • pp.576-584
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    • 2009
  • A novel tunable transconductor is presented. Input transistors operate in the triode region to achieve programmable voltage-to-current conversion. These transistors are kept in the triode region by a novel negative feedback loop which features simplicity, low voltage requirements, and high output resistance. A linearity analysis is carried out which demonstrates how the proposed transconductance tuning scheme leads to high linearity in a wide transconductance range. Measurement results for a 0.5 ${\mu}m$ CMOS implementation of the transconductor show a transconductance tuning range of more than a decade (15 ${\mu}A/V$ to 165 ${\mu}A/V$) and a total harmonic distortion of -67 dB at 1 MHz for an input of 1 Vpp and a supply voltage of 1.8 V.

Electrochemical Study of Three Stainless Steel Alloys and Titanium Metal in Cola Soft Drinks

  • Peralta-Lopez, D.;Sotelo-Mazon, O.;Henao, J.;Porcayo-Calderon, J.;Valdez, S.;Salinas-Solano, G.;Martinez-Gomez, L.
    • Journal of Electrochemical Science and Technology
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    • v.8 no.4
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    • pp.294-306
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    • 2017
  • Stainless steels and titanium alloys are widely used in the medical industry as replacement materials. These materials may be affected by the conditions and type of environment. In the same manner, soft drinks are widely consumed products. It is of interest for dental industry to know the behavior of medical-grade alloys when these are in contact with soft drinks, since any excessive ion release can suppose a risk for human health. In the present study, the electrochemical behavior of three stainless steel alloys and pure titanium was analyzed using three types of cola soft drinks as electrolyte. The objective of this study was to evaluate the response of these metallic materials in each type of solution (cola standard, light and zero). Different electrochemical techniques were used for the evaluation of the alloys, namely potentiodynamic polarization, linear polarization, and open-circuit potential measurements. The corrosion resistance of the stainless-steel alloys and titanium in the cola soft drinks was provided by the formation of a stable passive film formed by metal oxides. Scanning electron microscopy was used as a complementary technique to reveal corrosion phenomena at the surface of the materials evaluated.