El Repositorio Institucional de la Universidad FinisTerrae, es gestionado por el Sistema de Bibliotecas y tiene por objetivo permitir el acceso libre a la producción académica e institucional de la Universidad, aumentando la visibilidad de sus contenidos y garantizando su conservación.

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Tailoring of titanium dioxide thin film in dual radiofrequency plasma enhanced pulsed laser deposition
(Elservier, 2025-06-20) Villegas, Rodrigo; Tomlinson, Matías; Ureta De La Fuente, Valentina; Carrasco, Camilo; Miranda, Maximiliano; Fernandez, José Ignacio; Saavedra, Daniel; Retamal, María José; Inestrosa-Izurieta, María José; Singh, Dinesh Pratap; Angel, Felipe A.; Volkmann, Ulrich G.; Takamura, Yayoi; Bhuyan, Heman
Efficient and cost-effective methods to create photovoltaic materials are constantly being sought, with metal oxides like TiO2 playing a key role in this field. In this study, TiO2 thin films were grown on glass substrates using a dual radiofrequency (RF) plasma-enhanced pulsed laser deposition (PLD) system with a thermal budget that remained below 400 ◦C. The physical, chemical, and optical properties of the deposited thin films were studied as a function of low- and high-RF powers as well as deposition time. These parameters were found to impact the proportion of anatase and rutile phase and their crystallinity, as well as the oxygen vacancy concentration and band gap energy. These findings demonstrated the utility of dual RF plasma-enhanced PLD for precise modulation of TiO2 thin-films, offering promising applications in photovoltaics and photocatalysis.
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Adherence to an Early Exercise Plan Promotes Visceral Fat Loss in the First Month Following Bariatric Surgery.
(Springer, 2025) Pino-Zuñiga, Johanna; Lillo-Urzua, Paloma; Olivares-Galvez, Mariela; Palacio-Aguero, Ana; Duque, Juan Camilo; Luengas, Rafael; Cancino, Jorge
Background: The evidence supporting the benefits of early exercise in post-bariatric patients is growing. This study analyzed the effects of early exercise (1-week post-bariatric surgery) on body composition in patients with overweight and obesity 1 month after surgery. Methods: Thirty patients (age 36.5 ± 12.3 [range, 18-65] years; body mass index [BMI], 36.2 ± 12.3 kg/m2, range, 29-48) who underwent laparoscopic sleeve gastrectomy for bariatric surgery were instructed to participate in an exercise training program initiated on day 3 post-surgery and to follow a recommended protein intake of 60 g/day. After 1-month post-surgery, patients were stratified into those who adhered to exercise recommendations and those who did not. Pre- and post-differences in total weight loss (TWL), skeletal muscle mass (SMM), fat mass (FM), and visceral fat mass (VFM) were compared. Results: TWL, SMM, and FM loss were similar between non-adherent and adherent subjects (10.2 ± 3.5 kg and 11.9 ± 3.6 kg; p = 0.2; 2.9 ± 1.0 kg and 3.2 ± 1.2; p = 0.2; 6.2 ± 2.1 kg and 7.5 ± 3.6 kg; p = 0.2, respectively), whereas VFM was markedly reduced in the adherent group (29.9 ± 18.2 cm2 vs 14.6 ± 9.4 cm2; p = 0.01) compared to the non-adherent group. When the group was divided according to adherence to exercise and protein intake or non-adherence to both conditions, there was a significant difference in TWL, FM, and VFM losses (p < 0.05). In contrast, no differences in SMM were found. Conclusions: Early exercise training accelerated visceral fat mass loss during the initial recovery period in patients after bariatric surgery. Additionally, adherence to daily protein intake recommendations can increase total body weight and fat mass loss.
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Skeletal muscle Rac1 mediates exercise training adaptations towards muscle glycogen resynthesis and protein synthesis
(Elsevier, 2025-08-28) Raun, Steffen H.; Henriquez-Olguín, Carlos; Frank, Emma; Schlabs, Farina; Hahn, Nanna Just; Roland Knudsen, Jonas; Ali, Mona S.; Andersen, Nicoline R.; Møller, Lisbeth L.V.; Davey, Jonathan; Qian, Hongwei; Coelho, Ana; Carl, Christian S.; Voldstedlund, Christian T.; Kiens, Bente; Holmdahl, Rikard; Gregorevic, Paul; Jensen, Thomas E.; Deshmukh, Atul S.; Richter, Erik A.; Sylow, Lykke
Long-term exercise training elicits tremendous health benefits; however, the molecular understanding is incomplete and identifying therapeutic targets has been challenging. Rho GTPases are among the most regulated groups of proteins after exercise in human skeletal muscle, yet, unexplored candidates for mediating the effects of exercise training. We found that the Rho GTPase Rac1 was activated acutely after multiple exercise modalities in human skeletal muscle. Loss of Rac1 specifically in muscle attenuated contraction-induced muscle protein synthesis, diminished improvements in running capacity, and prevented muscle hypertrophy after exercise training in mice. Additionally, Ncf1* mice revealed that Rac1 regulated glycogen resynthesis via a NOX2-dependent mechanism. Molecularly, Rac1 was required for contraction-induced p38MAPK signaling towards HSP27, MNK1, and CREB phosphorylation. In vivo muscle-targeted overexpression of a hyperactive Rac1-mutant elevated reactive oxidant species production during exercise but did not affect muscle mass. Using mass spectrometry-based proteomics, we found that loss or gain of Rac1 muscle protein affected pathways related to cytoskeleton organization, muscle adaptation, and large ribosomal subunits. Thus, skeletal muscle Rac1 mediates both molecular and functional adaptation to exercise training.
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mTOR Ser1261 is an AMPK-­ dependent phosphosite in mouse and human skeletal muscle not required for mTORC2 activity
(John Wiley & Sons Inc., 2025-01-31) Li, Jingwen; Madsen, Agnete B.; Knudsen, Jonas R.; Henríquez-Olguín, Carlos; Persson, Kaspar W.; Li, Zhencheng; Raun, Steffen H.; Li, Tianjiao; Kiens, Bente; Wojtaszewski, Jørgen F. P.; Richter, Erik A.; Nogara, Leonardo; Blaauw, Bert; Ogasawara, Riki; Jensen, Thomas E.
The kinases AMPK, and mTOR as part of either mTORC1 or mTORC2, are major orchestrators of cellular growth and metabolism. Phosphorylation of mTOR Ser1261 is reportedly stimulated by both insulin and AMPK activation and a regulator of both mTORC1 and mTORC2 activity. Intrigued by the possibilities that Ser1261 might be a convergence point between insulin and AMPK signaling in skeletal muscle, we investigated the regulation and function of this site using a combination of human exercise, transgenic mouse, and cell culture models. Ser1261 phosphorylation on mTOR did not respond to insulin in any of our tested models, but instead responded acutely to contractile activity in human and mouse muscle in an AMPK activity-dependent manner. Contraction-stimulated mTOR Ser1261 phosphorylation in mice was decreased by Raptor muscle knockout (mKO) and increased by Raptor muscle overexpression, yet was not affected by Rictor mKO, suggesting most of Ser1261 phosphorylation occurs within mTORC1 in skeletal muscle. In accordance, HEK293 cells mTOR Ser1261Ala mutation strongly impaired phosphorylation of mTORC1 substrates but not mTORC2 substrates. However, neither mTORC1 nor mTORC2-dependent
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Intracellular and extracellular redox signals during exercise and aging
(Elsevier, 2025-10-29) Caporossi, Daniela; Jackson, Malcom J.; Henríquez-Olguín, Carlos
Regular physical activity enhances systemic health and resilience, partly through the generation of reactive oxygen species (ROS) that serve as key modulators of redox-sensitive signaling pathways. This review explores how redox signaling mediates both local and systemic responses to exercise, with particular focus on skeletal muscle and aging. We first examine the compartmentalized generation of ROS within myofibers, highlighting the distinct contributions of mitochondrial and NADPH oxidase systems and the context-dependent nature of oxidative eustress versus distress. We then detail how redox signals initiate adaptive responses that extend beyond muscle through the release of exerkines, cytokines, peptides, and metabolites, and their packaging within extracellular vesicles (EVs). These circulating factors facilitate interorgan communication and reinforce systemic redox homeostasis. Aging disrupts these processes, leading to impaired redox signaling, neuromuscular degeneration, and diminished responsiveness to exercise. Notably, animal models such as Sod1-deficient mice underscore the importance of neuronal redox control in sarcopenia. Finally, we highlight how exercise-induced EVs may counteract age-associated dysfunction by delivering redox-regulatory molecules to distant tissues. Understanding the molecular interplay between redox signals and systemic adaptation offers promising avenues for therapeutic strategies targeting metabolic and neuromuscular decline in aging.