165 research outputs found

    Reply to `Comment on ``Helmholtz Theorem and the V-Gauge in the Problem of Superluminal and Instantaneous Signals in Classical Electrodynamics" by A. Chubykalo Et Al' by J. A. Heras [FOUND. Phys. Lett. vol. 19(6) p. 579 (2006)]

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    This is the reply to `COMMENT ON ``HELMHOLTZ THEOREM AND THE V-GAUGE IN THE PROBLEM OF SUPERLUMINAL AND INSTANTANEOUS SIGNALS IN CLASSICAL ELECTRODYNAMICS" BY A. CHUBYKALO ET AL' BY J. A. HERAS [FOUND. PHYS. LETT. vol. 19(6) p. 579 (2006)]Comment: 5 pages, submitted to Foundations of Physic

    Transcriptomic analysis of the hepatic response to stress in the red cusk-eel (Genypterus chilensis): Insights into lipid metabolism, oxidative stress and liver steatosis

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    Indexación: Scopus.Teleosts exhibit a broad divergence in their adaptive response to stress, depending on the magnitude, duration, and frequency of stressors and the species receiving the stimulus. We have previously reported that the red cusk-eel (Genypterus chilensis), an important marine farmed fish, shows a physiological response to stress that results in increased skeletal muscle atrophy mediated by over-expression of components of the ubiquitin proteasome and autophagy-lysosomal systems. To better understand the systemic effects of stress on the red cusk-eel metabolism, the present study assessed the transcriptomic hepatic response to repetitive handling-stress. Using high-Throughput RNA-seq, 259 up-regulated transcripts were found, mostly associated with angiogenesis, gluconeogenesis, and triacylglyceride catabolism. Conversely, 293 transcripts were down-regulated, associated to cholesterol biosynthesis, PPARα signaling, fatty acid biosynthesis, and glycolysis. This gene signature was concordant with hepatic metabolite levels and hepatic oxidative damage. Moreover, the increased plasmatic levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase) and AP (alkaline phosphatase), as well as liver histology suggest stress-induced liver steatosis. This study offers an integrative molecular and biochemical analysis of the hepatic response to handling-stress, and reveals unknown aspects of lipid metabolism in a non-model teleost.http://journals.plos.org/plosone/article?id=10.1371/journal.pone.017644

    Effects of resistance training program on muscle mass and muscle strength and the relationship with cognition in Older Women

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    The aim of this study was to study the effects of a resistance training programme on Maximal Dynamic Strength (MDS) and muscle morphology of the upper limbs (UL) and lower limbs (LL), as well as to analyse their association with cognition, in a population of older women. The study had a duration of 24 months and a total of 93 Chilean older women participated. The participants were divided into two groups: The Physical Activity Group (PAG, n = 45, age (X ± SD) 77.93 ± 3.54 years), and the Sedentary Group (SG, n = 48, age (X ± SD) 77.71 ± 3.41 years). The PAG carried out a muscle strength training routine twice per week. The following variables were evaluated: Muscle function through maximal dynamic strength (1RM), muscle morphology through arm and calf circumference (AC and CC, respectively), and cognition (Mini Mental State Examination: MMSE). The results show that the SG recorded significant decreases (percent changes; p < 0.05) in the analysed variables: MMSE (-3.5%), MDS in UL (-3.3%), MDS in LL (-4.1%), AC (-4.5%), CC (-4.1%), and BMI (-3.1%). However, the PAG improved significantly in all the analysed variables except in BMI: MMSE (3.9%), MDS in UL (3.6%), MDS in LL (3.5%), AC (1.8%), and CC (2.5%). Moreover, there was a significant association (p < 0.05) between the changes in the muscle strength variables and the changes in cognition level. Therefore, it can be concluded that a two-year muscle strength training programme (load intensity between 30-55% 1RM) in older women improves Maximal Dynamic Strength in UL and LL, as well as muscle mass in arms and calves. Furthermore, it can be asserted that the changes in muscle strength levels could predict the changes in the levels of cognition in older women. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Experiencia en el tratamiento quirúrgico del angiofibroma nasal juvenil en Hospital de Especialidades No 2 Lic. Luis Donaldo Colosio Murrieta. Instituto Mexicano del Seguro Social de Ciudad Obregón, Sonora

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    Objective: To present our experience and assess the recurrence of juvenile nasopharyngeal angiofibroma after a surgical treatment (open versus endoscopic approach) in the country’s northwestern Department of Otorhinolaryngology. Materials and methods: An observational, retrospective, analytical study. The medical records of patients diagnosed with juvenile nasopharyngeal angiofibroma, who were treated at the Department of Otorhinolaryngology – Head and Neck Surgery of this institution from 2014 to 2017, were reviewed. Results: A total of 19 patients diagnosed with juvenile nasopharyngeal angiofibroma underwent a surgical procedure, out of which 14 had an open surgery and 5 an endoscopic one. Recurrence accounted for 50 % and 40 %, respectively, which was not statistically significant (p = 0.88). However, other variables were compared, such as the need for admission to the Intensive Care Unit (ICU), which was represented by 71 % in the case of the open approach and 20 % for the endoscopic approach, where a significant difference was found (p = 0.04). Conclusions: The study shows no statistically significant advantage of the endoscopic approach versus the open approach, but demonstrates less need for ICU admissions, which would reduce healthcare costs

    Removal of Cd (II) from aqueous solutions by batch and continuous process using chitosan sulfate dispersed in a calcium alginate hydrogel

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    A novel chitosan sulfate (ChS) which is insoluble at acidic pHs was synthesized and then dispersed in calcium alginate hydrogel beads to be used to remove Cd(II) from aqueous solutions at acidic pHs using a batch process and a continuous process. By batch wise experiments, it was found that the equilibrium adsorption capacity of the Alg-ChS beads increase with the increase in the initial concentration of Cd; however, the percentage of Cd removal decreased.The Freundlich model had the best fit to the experimental adsorption equilibrium data. The adsorption rate of Cd onto Alg-ChS beads followed the kinetic model of pseudo-second order and the time to reach equilibrium increased slightly with increasing initial concentration of Cd(II). The removal of Cd using a fixed bed column (continuous process) packed with the Alg-ChS beads had a much higher efficiencythan the Batch process. An adsorption mechanism of Cd(II) onto the Alg-ChS beads was proposed using the FTIR, and XPS spectra of samples of Cd(II) adsorbed onto ChS and the mechanisms of adsorption of metals by alginate and chitosan proposed by other authors

    The antimalarial drug amodiaquine stabilizes p53 through ribosome biogenesis stress, independently of its autophagy-inhibitory activity

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    Pharmacological inhibition of ribosome biogenesis is a promising avenue for cancer therapy. Herein, we report a novel activity of the FDA-approved antimalarial drug amodiaquine which inhibits rRNA transcription, a rate-limiting step for ribosome biogenesis, in a dose-dependent manner. Amodiaquine triggers degradation of the catalytic subunit of RNA polymerase I (Pol I), with ensuing RPL5/RPL11-dependent stabilization of p53. Pol I shutdown occurs in the absence of DNA damage and without the subsequent ATM-dependent inhibition of rRNA transcription. RNAseq analysis revealed mechanistic similarities of amodiaquine with BMH-21, the first-in-class Pol I inhibitor, and with chloroquine, the antimalarial analog of amodiaquine, with well-established autophagy-inhibitory activity. Interestingly, autophagy inhibition caused by amodiaquine is not involved in the inhibition of rRNA transcription, suggesting two independent anticancer mechanisms. In vitro, amodiaquine is more efficient than chloroquine in restraining the proliferation of human cell lines derived from colorectal carcinomas, a cancer type with predicted susceptibility to ribosome biogenesis stress. Taken together, our data reveal an unsuspected activity of a drug approved and used in the clinics for over 30 years, and provide rationale for repurposing amodiaquine in cancer therapy

    De semillas a bioenergía: un camino de conversión para la valorización de semillas de ricino y jatrofa

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    The world’s energy matrix can be diversified with biodiesel from castor and jatropha oil. Hence, the objective of this study was to assess a conversion path for the valorization of castor and jatropha seeds. The results showed the maximum extraction of castor oil at 90 °C, 2 rpm, and 6 mm nozzle, achieving a yield of 36.97% and for jatropha oil at 100 °C, 1.5 rpm, and 10 mm nozzle, achieving a yield of 20.11%. The acid value and cloud point of castor and jatropha oil were 0.797 and 23.44 mg KOH/g, 10±1 °C and 12±0.55 °C, respectively; while the pour point was -3 °C for both. The acid value and cloud point for biodiesels ranged from 0.26-0.43 mg KOH/g, and -12.50-6.10 °C, respectively. The viscosity of oils and biodiesel ranged from 0.02-1.3 P. GC-MS indicated 66.38% of methyl ricinoleate in castor biodiesel and 31.64% of methyl oleate in jatropha biodiesel. The HHV for castor and jatropha biodiesel ranged from 32.37-40.25 MJ/kg.La matriz energética mundial puede diversificarse con biodiesel de ricino y de jatrofa. Por lo tanto, el objetivo de este trabajo fue evaluar la ruta de conversión de las semillas de ricino y jatrofa. Los resultados mostraron que la máxima extracción de aceite de ricino se dio a 90 °C, 2 rpm, y boquilla de 6 mm, alcanzando un rendimiento de 36,97% y para el aceite de jatrofa fue a 100 °C, 1,5 rpm, y boquilla de 10 mm, obteniendo un rendimiento de 20,11%. El índice de acidez y punto de nube del aceite de ricino y jatrofa fue de 0,797 y 23,44 mg de KOH/g, 10 ± 1 °C y 12 ± 0,55 °C, respectivamente, mientras que el punto de fluidez fue de -3 °C para ambos. El índice de acidez y el punto de nube del biodiésel de ricino y jatropha fueron 0,43 y 0,26 mg KOH/g, -12,50 °C y 6,10 °C, respectivamente. La viscosidad dinámica de los aceites y el biodiesel osciló entre 0,02 y 1,3 P. El análisis GC-MS indicó 66,38% de ricinoleato de metilo en biodiesel de higuerilla y 31,64% de oleato de metilo en biodiesel de jatrofa. El HHV para el biodiésel de ricino y jatrofa osciló entre 32,37 y 40,25 MJ/kg

    Milagrito: a TeV air-shower array

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    Milagrito, a large, covered water-Cherenkov detector, was the world's first air-shower-particle detector sensitive to cosmic gamma rays below 1 TeV. It served as a prototype for the Milagro detector and operated from February 1997 to May 1998. This paper gives a description of Milagrito, a summary of the operating experience, and early results that demonstrate the capabilities of this technique.Comment: 38 pages including 24 figure

    Hybrid self-assembled materials constituted by ferromagnetic nanoparticles and tannic acid : A theoretical and experimental investigation

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    Hybrid magnetite materials are interesting for both biomedical and catalytic applications due to their well-known biocompatibility, as well as their magnetic and electric properties. In this work we prepared Fe O nanoparticles (NPs) coated with tannic acid (TA), a natural polyphenol, through two different synthetic routes, aiming to understand the influence of TA in the synthesis step and contribute to the development of water-dispersible magnetic materials. The coating process was verified by information obtained from transmission electron microscopy (TEM), zeta-potential and Fourier transform infrared (FTIR) spectroscopy. The incorporation of TA after Fe O NPs production generated spherical NPs smaller than 10 nm, suggesting that TA plays a fundamental role in the nucleation and organization of Fe O NPs. Data from both density functional theory (DFT) and FTIR allowed us to infer that Fe O interacts mainly with the carbonyl groups of TA. Hybrid materials having improved water-dispersibility are very attractive for biomedical applications
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