BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//7.2.3.1//EN TZID:America/New_York X-WR-TIMEZONE:America/New_York BEGIN:VEVENT UID:0-7827@eng.ufl.edu DTSTART;TZID=America/New_York:20251013T150000 DTEND;TZID=America/New_York:20251013T160000 DTSTAMP:20251201T182101Z URL:https://www.eng.ufl.edu/news-events/events/bme-postdocs-seminar-sandra -mara-ferreira-daniela-p-valdes/ SUMMARY:BME Postdocs Seminar: Sandra Mara Ferreira &\; Daniela P. Valdé s DESCRIPTION:Dr. Sandra Mara Ferreira: "GABA modulates pancreatic beta-cell function through Ca2+ signaling"\nDr. Daniela P. Valdés: "Do scientists d ream of plastic mice? Phantoms in Magnetic Hyperthermia and Magnetic Parti cle Imaging"\n--\nSandra Mara Ferreira\, PhD\nPostdoctoral Fellow\, Phelps Lab\nBiomedical Engineering\, University of Florida\n"GABA modulates panc reatic beta-cell function through Ca2+ signaling"\nAbstract: Pancreatic is lets are endocrine micro-organs located in the pancreas and are composed o f multiple endocrine cell types (beta\, alpha\, and delta). These cells se crete different hormones (insulin\, glucagon\, and somatostatin\, respecti vely) that modulate blood glucose and\, in a paracrine fashion\, control t he adjacent cells. An imbalance of the secretions of these hormones can le ad to metabolic diseases. Type 1 diabetes results from the failure or loss of insulin secretion. The pancreatic islets also secrete signaling molecu les that modulate the pancreatic islet function. One of these molecules is the neurotransmitter gamma-aminobutyric acid (GABA)\, synthesized and sec reted by beta cells. GABA is an inhibitory neurotransmitter in the central nervous system (CNS)\, and beta cells are the location that has the most GABA outside of the CNS\, indicating GABA is essential for pancreatic isle t function. However\, the exact role of GABA in the pancreatic islets is n ot yet clear. Here\, we investigated the modulation of beta cell function by GABA to clarify and reveal its role in the islet in both normal and dis ease states.\nBio: Dr. Sandra Mara Ferreira is a postdoctoral assistant in the Phelps Lab. Originally\, she is from Brazil and got her undergraduate degree in Biological Sciences from the University of Maringa\, in souther n Brazil. She got her Master’s and PhD in Molecular and Functional Biolo gy at the University of Campinas\, Sao Paulo\, Brazil. Her studies have be en focused on pancreatic islet biology\, specifically on the mechanisms th at control pancreatic beta cell function.\n--\nDaniela P. Valdés\, PhD\nP ostdoctoral Fellow\, Rinaldi-Ramos Lab\nChemical Engineering\, University of Florida\n"Do scientists dream of plastic mice? Phantoms in Magnetic Hyp erthermia and Magnetic Particle Imaging"\nAbstract: Biomedical imaging and therapeutic-technology development have traditionally relied on animal mo dels for their testing and validation. Synthetic phantoms engineered to re plicate physiological and/or anatomical properties offer a controlled alte rnative that supports the ethical principles of the 3Rs: replace anima l use where possible\, reduce the number of animals required\, and r efine protocols to minimize pain. This seminar will highlight how phanto ms enable the simulation of complex in vivo scenarios and advance magnetic nanoparticle (MNP) research in therapy and imaging.\nMagnetic hyperthermi a\, as a cancer treatment modality\, relies on heat generation through the relaxation of MNPs within the intracellular environment. The efficiency o f this process\, often quantified by the specific power absorption (SPA)\, can be influenced by the viscosity of the medium in which the MNPs are di spersed [1]. To address this\, we used adjustable-viscosity polyacrylamide gels [2] as a cytosol emulator to characterize MNP behavior under physiol ogically relevant conditions. Moreover\, the temperature increment during hyperthermia experiments was measured with a thermographic camera and spat io-temporal profiles were obtained from the videos\, contributing to the d evelopment of non-invasive temperature monitoring techniques [3]. To trans late these findings into a realistic treatment workflow\, we use phantom m ice with a fillable breast cancer tumor to test MNPs and experimental cond itions\, as well as develop a treatment workflow.\nFor these novel MNP-bas ed treatments\, information on the particle distribution is key to evaluat ing their effectiveness as the literature suggests that only 0.7% of the i njected dose reaches the target regions [4]. In magnetic particle imaging (MPI)\, MNPs that are being injected into a subject for treatment can be a lso used as tracers to get a distribution map that can be registered with an anatomical image. We used an anatomically correct mouse phantom based o n the Digimouse atlas for imaging of different in vivo scenarios. The fill able liver was used to emulate MNP accumulation due to macrophage uptake a nd a set of capillaries was placed in cavities to evaluate different types of tumors: superficial (flank)\, internal (brain) and metastasis (lung). The segmentation of the MPI signals in the target sites was done through t hreshold (with 50% of the maximum criteria) and constant volume spheres. Q uantification of the iron mass in these segments was done conventionally a nd by subtracting the signal in a background scan with a filled liver but no capillary\, accounting for the spillover effect from the adjacent liver [5].\nThese phantom-based experiments enable the systematic investigation of MNP behavior under relevant conditions\, both physiologically and anat omically\, supporting both imaging and therapeutic development. These resu lts not only advance the precision of MNP-based therapies but also contrib ute to reproducible and ethically-responsible research aligned with the 3R s framework.\nReferences\n[1] D. Cabrera\, J Nanoparticle Res 17\, 121 (20 15)\n[2] T. Yano\, Biosci Biotechnol Biochem 57\, 528 (1993)\n[3] D.P. Val dés et al.\, Phys Rev Applied 19\, 014042 (2023)\n[4] S. Wilhelm et al.\, Nat Rev Mater 1\, 5 (2016)\n[5] A. Shakeri-Zadeh et al.\, npj imaging 3\, 20 (2025)\nBio: Dr. Daniela P. Valdés is a Postdoctoral Associate in t he Rinaldi-Ramos Laboratory\, Department of Chemical Engineering at the Un iversity of Florida (2025)\, where she focuses on magnetic nanoparticle (M NP) based imaging and therapeutic technologies. In particular\, she genera tes workflows for magnetic particle imaging (MPI) segmentation and quantif ication of MNPs in vitro and in vivo. She earned her PhD in Physics at the Magnetic Resonance Laboratory\, Centro Atómico Bariloche\, supported by a CONICET scholarship in 2024. Her doctoral thesis\, supervised by Dr. Emi lio De Biasi and Dr. Enio Lima Jr.\, is titled Magnetic Hyperthermia in Phantoms: From Theory to Experiment. Daniela has also served as a teaching assistant for the Experimental Physics I (2019-2022) and Quantum Mechanic s II (2023-2024) courses at Instituto Balseiro. She holds an MSc in Physic s (2018) and a BSc in Physics (2017) from Instituto Balseiro\, where she i nvestigated the MNP interaction effect magnetic hyperthermia treatment per formance. CATEGORIES:Seminars LOCATION:Communicore Room C1-7\, 1249 Center Dr.\, Gainesville\, FL\, 32610 \, United States GEO:29.640849;-82.34479 X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=1249 Center Dr.\, Gainesvil le\, FL\, 32610\, United States;X-APPLE-RADIUS=100;X-TITLE=Communicore Roo m C1-7:geo:29.640849,-82.34479 END:VEVENT BEGIN:VTIMEZONE TZID:America/New_York X-LIC-LOCATION:America/New_York BEGIN:DAYLIGHT DTSTART:20250309T030000 TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT END:DAYLIGHT END:VTIMEZONE END:VCALENDAR