Two graduate students will present their research at the next Beckman Institute Graduate Student Seminar: Md Saddam Hossain Joy, mechanical science and engineering; and Aravind Baby, materials science and engineering. The event will take place at noon Wednesday, Oct. 4 in 5602 Beckman Institute.
Register to attend and receive lunch.
"Synapses without tension fail to fire in an in vitro network of hippocampal neurons"
Neuronal firing is the basis for all neurological functions including learning and memory, cognition, and voluntary and involuntary motion. Anomaly in firing is related to neurogenerative diseases including Alzheimer's disease, Huntington’s disease, Amyotrophic Lateral Sclerosis, or ALS, and Parkinson’s disease. Biological factors have long been considered as the determinants of neuronal firing. However, there is an emergent body of evidence suggesting that biophysical factors, including the contractility of neurons, also play a critical role in enabling neurons to function, such as the clustering of neurotransmitter vesicles at neuro-muscular synapses. Here, we reveal that primary neurons of the hippocampus, the critical part of the brain attributed to cognition, memory and learning, become contractile after synaptogenesis as they form a neuronal network in vitro. Neurons cannot fire if contractility is relaxed. They resume firing with the restoration of contractility. We developed an ultra-sensitive force sensor with 1 nN resolution to measure, for the first time, the time evolution of neural contractility in the 3D extracellular matrix during synaptogenesis and formation of the network. We used MEA and iGlusnFR, a genetic reporter of glutamate release by neurons, to quantify neuronal firing at the network scale and at single synapse scale respectively. We relaxed the neurons using Blebbistatin, an inhibitor of Myosin II. Neuronal tension and firing decrease significantly with Blebbistatin, but they recover with drug washout. Our results suggest that hippocampal neural contractility may play a crucial role in memory, learning, cognition, and various neuropathologies.
Md Saddam Hossain Joy is a fifth-year Ph.D. student in the Department of Mechanical Science and Engineering working under the mentorship of Professor Taher Saif. His research is centered around understanding the role of mechanical tension on neuronal function, and he also holds a keen interest in investigating how exercise contributes to maintaining good cognitive health. Joy completed his undergraduate and master’s degrees in mechanical engineering from Bangladesh University of Engineering and Technology. Outside his academic commitments, he is passionate about gardening and fishing.
"Direct, low-temperature refurbishment of sulfated lead-acid battery anodes through organic-acid chelation treatment"
Conventional methods of lead-acid battery recycling use high-temperature pyrometallurgical processes and are one of the most polluting industrial processes globally. Spent batteries are crushed to remove the active material for recycling. However, almost 70% of this recycled Pb is used again for making new LABs. Hence, in-situ refurbishing LABs at low temperatures without destroying them promises to be both environmentally and economically advantageous, as it reduces both the associated pollution and the overhead costs for a centralized recycling paradigm. We aim at developing chelating chemicals to remove hard sulfation and retrieve the electrochemical capacity lost from failed commercial LAB anodes. Subsequently, we applied these chemistries in full commercial batteries while also exploring alternative surface reactions for the same goal. In this presentation, we report using ammonium acetate as an effective chelation agent to remove large crystals of lead sulfate from the surfaces of LAB anodes taken from spent commercial batteries. Scanning electron micrographs and X-ray diffractograms reveal the complete removal of hard sulfation and restoration of a microstructure comparable to unsulfated anodes. Galvanostatic cycling measurements reveal that an average of 94% of the lost capacity can be retrieved using the process. Treatment with ammonium acetate caused a mass loss of only 11% from the anodes and this dissolved Pb was retrieved with >99.9% efficiency using a simple potentiostatic electrodeposition. The low overpotential and high Faradaic efficiency of the electrodeposition present a significant improvement in energy costs. Biography:
Aravind Baby (Babs) is a fifth-year Ph.D. student in the Department of Materials Science and Engineering working under the mentorship of Professor Joaquín Rodríguez-López. His research involves exploring the chemistry of lead-acid batteries for understanding the mechanism of sulfation and reducing detrimental processes leading to self-discharge of the batteries for ultimately refurbishing failed batteries in-situ. Babs completed his undergraduate and master’s degrees in materials science from the Indian Institute of Science, Bangalore. Outside his academic commitments, he is passionate about mentorship, traveling, and performing arts.
Learn more about Beckman's Graduate Student Seminar Series.
Read Q&As with student researchers on Beckman's Student Researcher Spotlight page.
