Examinando por Autor "Fernández-Guzmán, Victor"

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Acceso Abierto
Ameliorative Effect of the Oral Administration of Chuquiraga spinosa in a Murine Model of Breast Cancer Induced with 7,12-Dimethylbenz[a]anthracene (DMBA)
(Pharmacognosy Journal, 2020-05-07) Arroyo-Acevedo, Jorge Luis; Herrera-Calderon, Oscar; Tinco-Jayo, Johnny Aldo; Rojas-Armas, Juan Pedro; Rauf, Abdur; Hañari-Quispe, Renán; Figueroa-Salvador, Linder; Fernández-Guzmán, Victor; Yuli-Posadas, Ricardo Ángel
Objective: To determine the ameliorative effect of the ethanolic extract of Chuquiraga spinosa (ChS) on 7,12-Dimethylbenz[a]anthracene (DMBA)-induced breast cancer in rats. Methods: 36 female Holztman rats were divided into 6 groups. I) The negative control group received physiological saline (PS). II) ChS-200 group received 200 mg/kg of ChS. III) DMBA group was induced with DMBA (20 mg/Kg) dissolved in PS and administrated orally for 15 weeks. IV) DMBA + ChS-50 group, V) DMBA + ChS-250 group, and VI) DMBA + ChS-500 group, which received the extract orally for 15 weeks after DMBA induction. All data were expressed as mean and standard deviation. One-way analysis of variance (ANOVA) followed by Dunnet test was carried out to compare the mean value of different groups Histopathological analysis was evaluated by using Image J software. Results: Hematology showed that the triglyceride level was significantly lowered (P< 0.01) and high-density lipoprotein (HDL) level was significantly increased (P <0.01) in groups III, IV and V. Also, ChS extract significantly lowered the C reactive protein (CRP) level (P <0.01) and malondialdehyde level (P<0.05). There was a significant decrease in the frequency of DMBA-induced micronucleated polychromatic erythrocyte (P<0.01). Conclusions: Chuquiraga spinosa showed an ameliorative effect on DMBA-induced breast cancer in rats as well as antioxidant, antitumor and antigenotoxic properties.
Acceso Abierto
Solar photovoltaic technology in isolated rural communities in Latin America and the Caribbean
(Elsevier, 2021-12-30) Miravet-Sánchez, Bárbara Liz; García-Rivero, Alberto E.; Yuli-Posadas, Ricardo A.; Inostroza-Ruiz, Luis Alberto; Fernández-Guzmán, Victor; Chávez-Juanito, Yuli Anabel; Rutti-Marin, José Miguel; Apesteguia-Infantes, José Alfonso
The main characteristics of photovoltaic (PV) energy and its current development in Latin American and Caribbean countries (LAC); its impact on the electrification of homes, health institutions, and schools in isolated or difficult-to-access communities; and, the advantages thereof are presented and discussed by replacing the use of traditional fuels such as firewood and kerosene in order to improve inhabitants ’health as well as reducing CO2 emissions. Countries like Nicaragua, Peru, Brazil, Argentina, and Chile stand out for their growing PV energy development in the region. A case study of the electrification process by PV systems shows very positive changes are manifested in terms of improving the quality of life of the inhabitants, and especially their physical and mental health state. In addition, CO2 emission reductions from electrifying 216 houses in the nine communities reach an annual amount of 2,164.19 t/yr, reducing firewood consumption by 2,123.39 t/yr and kerosene consumption by 40.80 t/yr However, LAC countries must adopt laws and regulations that regulate the use of PV energy, with an emphasis on recycling systems at the end of their life cycle.
Acceso Abierto
Understanding continuance usage of natural gas: a theoretical model and empirical evaluation
(MDPI, 2018-08-03) Fernández-Guzmán, Victor; Bravo, Edgardo R.
The adoption of natural gas increased notably last years, and there is some recognition that it improves the quality of life of inhabitants. While initial acceptance is an essential first step, the continued use is relevant to the long-term success of any technology. However, the literature on energy has focused on adoption and has devoted less attention to models that explain continuance usage. Accordingly, this study developed a model to explain continuance usage, grounded in Expectation-Confirmation Model (ECM). Unlike adoption models, confirmation of previous expectations and satisfaction with the experience of use have a relevant role in this phenomenon. Data was gathered through a questionnaire to 435 users of the service in a Latin American metropolis, and structural equations model was used for analysis. The results show that constructs of the ECM (perceived usefulness, disconfirmation, and satisfaction) influences on continuance intention. While the price impacts as expected, it is surprising that environmental consciousness strongly impacts the intention. These results may be useful for public agents to foster more comprehensive policies (beyond traditional: price and access), which include environmental and safety issues to consolidate the use of this energy source. Energy companies should develop strategies to manage consumer expectations and loyalty programs based on a high level of satisfaction.