UMBC Chemical, Biochemical & Environmental Engineering Department

Permanent URI for this collectionhttp://hdl.handle.net/11603/49

Faculty in our department focus their research in nine core areas encompassing biological, environmental, and educational research. Our department offers an undergraduate course of study leading to a B.S. in Chemical Engineering through three tracks of study: (i) Traditional Track, (ii) Biotechnology and Bioengineering Track and (iii) Environmental Engineering and Sustainability track. We also offer both M.S. and Ph.D. degrees through two different graduate programs. Details can be found on our website: http://www.umbc.edu/cbe

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Current Strategies and Future Directions of Wearable Biosensors for Measuring Stress Biochemical Markers for Neuropsychiatric Applications
(Wiley, 2024-12-17) Sheffield, Zach; Paul, Priyanka; Krishnakumar, Shraddha; Pan, Prof Dipanjan
Most wearable biosensors aimed at capturing psychological state target stress biomarkers in the form of physical symptoms that can correlate with dysfunction in the central nervous system (CNS). However, such markers lack the specificity needed for diagnostic or preventative applications. Wearable biochemical sensors (WBSs) have the potential to fill this gap, however, the technology is still in its infancy. Most WBSs proposed thus far target cortisol. Although cortisol detection is demonstrated as a viable method for approximating the extent and severity of psychological stress, the hormone also lacks specificity. Multiplex WBSs that simultaneously target cortisol alongside other viable stress-related biochemical markers (SBMs) can prove to be indispensable for understanding how psychological stress contributes to the pathophysiology of neuropsychiatric illnesses (NPIs) and, thus, lead to the discovery of new biomarkers and more objective clinical tools. However, none target more than one SBM implicated in NPIs. Till this review, cortisol's connection to dysfunctions in the CNS, to other SBMs, and their implication in various NPIs has not been discussed in the context of developing WBS technology. As such, this review is meant to inform the biosensing and neuropsychiatric communities of viable future directions and possible challenges for WBS technology for neuropsychiatric applications.
Chloride Interferences in Wet Chemical Oxidation Measurements: Plausible Mechanisms and Implications
(ACS, 2024-12-04) Chiu, Yin Ting T.; Burns, Alyssa M.; Rosanka, Simon; Hu, Tiffany; Hennigan, Christopher; Carlton, Annmarie G.
Wet chemical oxidation (WCO) methods measure total organic carbon (TOC) in aqueous solutions through the formation and detection of carbon dioxide (CO₂). Prior research documents chloride (Cl⁻) interference during WCO. However, the mechanism that determines WCO interference is not established. We investigate WCO and find that formic acid exhibits TOC recovery (89–108%) within measurement uncertainty in the presence of Cl⁻, while acetic acid recovery is substantially reduced (3–67%). We postulate that chlorine radical (•Cl) formation during WCO alters oxidation pathways for organic compounds with methyl groups to form stable halogenated organic species that are thus not detected as CO₂, reducing observed TOC recovery. We develop a kinetic model of elementary step reactions that reproduces observed TOC recoveries at multiple organic (1 and 5 ppm of C) and Cl⁻ (>0.01 M) concentrations for both acetic and formic acids. Independent experiments with pyruvic acid and different halogen salts are consistent with the proposed mechanism. Our findings provide a plausible mechanistic explanation for Cl⁻ interference in WCO-derived TOC measurements of environmental samples for which halogenated salts are present. A plausible mechanism provides a more complete understanding of how and why the TOC is biased low in environmental aquatic samples from saline environments when WCO is employed.
Advancing Cell-Free Manufacturing: Challenges in Scale-up and Automation Workshop Report
(NIST, 2024-11-20) Romantseva, Eugenia; Oliveira, Fernanda Piorino Macruz de; Sundberg, Chad Alan; Sittampalam, G. Sitta; Strychalski, Elizabeth
The National Institute of Standards and Technology (NIST) and the National Center for Advancing Translational Sciences (NCATS) convened the workshop Advancing Cell-free Manufacturing: Challenges in Scale-up and Automation in Rockville, Maryland in February 2024. This workshop brought together over fifty participants, representing the interests and needs of stakeholders in academic, industrial, and government settings. Together, through various plenary discussions, case studies, and working groups, participants broadly surveyed the field and focused on identifying both near-term and long-term needs to support cell-free expression systems. This report synthesizes the workshop discussion and presents actionable recommendations aimed at removing the remaining barriers to realizing the full impact of CFE systems on biomanufacturing and applications of biotechnology.
In Context Learning and Reasoning for Symbolic Regression with Large Language Models
(2024-10-22) Sharlin, Samiha; Josephson, Tyler R.
Large Language Models (LLMs) are transformer-based machine learning models that have shown remarkable performance in tasks for which they were not explicitly trained. Here, we explore the potential of LLMs to perform symbolic regression -- a machine-learning method for finding simple and accurate equations from datasets. We prompt GPT-4 to suggest expressions from data, which are then optimized and evaluated using external Python tools. These results are fed back to GPT-4, which proposes improved expressions while optimizing for complexity and loss. Using chain-of-thought prompting, we instruct GPT-4 to analyze the data, prior expressions, and the scientific context (expressed in natural language) for each problem before generating new expressions. We evaluated the workflow in rediscovery of five well-known scientific equations from experimental data, and on an additional dataset without a known equation. GPT-4 successfully rediscovered all five equations, and in general, performed better when prompted to use a scratchpad and consider scientific context. We also demonstrate how strategic prompting improves the model's performance and how the natural language interface simplifies integrating theory with data. Although this approach does not outperform established SR programs where target equations are more complex, LLMs can nonetheless iterate toward improved solutions while following instructions and incorporating scientific context in natural language.
Targeted K-Edge Nanoprobes From Praseodymium and Hafnium for Ratiometric Tracking of Dual Biomarkers using Spectral Photon Counting CT
(Wiley, 2024-10-07) Gunaseelan, Nivetha; Moitra, Parikshit; Saha, Pranay; Aditya, Teresa; Moghiseh, Mahdieh; Jonker, Kevin; Gieseg, Steven; Butler, Anthony; Kamal, Fadia; Pan, Prof Dipanjan
Utilizing metal nanoprobes with unique K-edge identities to visualize complementary biological activities simultaneously can provide valuable information about complex biological processes. This study describes the design and preparation of an innovative pair of K-edge metal nanoprobes and demonstrates the feasibility of their simultaneous quantitative detection using spectral photon-counting computed tomography (SPCCT). Glycosaminoglycan (GAG) capped nanoparticles (ca. 15–20 nm) targeting two distinct components of the cartilage tissue, namely, aggrecan (acan) and aggrecanase (acanase) are designed and synthesized. These targeted nanoparticles comprised of praseodymium (Pr) and hafnium (Hf), with well-separated K-edge energies, enable simultaneous and ratiometric imaging of dual biomarkers in cartilage tissue. Following extensive physico-chemical characterization of the ligand-targeted particles, the feasibility of homing dual biomarkers in vitro is demonstrated. The material discrimination and simultaneous quantification of these targeted particles are also achieved and corroborated with inductively coupled plasmon spectroscopy. For the first time, the use of praseodymium is reported as a contrast agent for SPCCT imaging and demonstrates the ability to pair it with hafnium nanoprobes for multicontrast imaging of diseases. Importantly, the potential for ratiometric molecular imaging and tracking of osteoarthritis (OA) progression is shown with SPCCT K-edge based imaging approach.
Lee Blaney Assumes Presidency Of The Association Of Environmental Engineering And Science Professors
(UMBC News, 2024-09-16) Meyers, Catherine; Demond, Marlayna
Professor Lee Blaney, in the Department of Chemical, Biochemical, and Environmental Engineering, formally assumed the role of president of the Association of Environmental Engineering and Science Professors (AEESP) at a board of directors meeting in early September. AEESP is a nonprofit organization founded in 1963 to foster inclusive connections between environmental engineering and science researchers and educators. It provides programs for members to develop the academic networks and career skills needed for professional success, increase equitable societal impact of environmental engineering and science scholarship and creative expression, and reimagine the skills necessary for environmental engineers and scientists to provide solutions… Continue Reading Lee Blaney assumes presidency of the Association of Environmental Engineering and Science Professors
Incremental Inverse Design of Desired Soybean Phenotypes
(ACS, 2024-09-30) Zavorskas, Joseph; Edwards, Harley; Marten, Mark; Harris, Steven; Srivastava, Ranjan
We present an application of computational inverse design, which reverses the conventional trial-and-error forward design paradigm, optimizes biological phenotype by directly modifying genotype. The limitations of inverse design in genotype-to-bulk phenotype (G-BP) mapping can be addressed via an established design paradigm: “design, build, test, learn” (DBTL), where computational inverse design automates both the design and learn phases. In any context, inverse design is limited by the fundamental “one-to-many” nature of the inverse function. G-BP inverse design is further limited by the number of single nucleotide polymorphisms that can be made to a member of the population while maintaining feasibility of genotype creation and biological viability. Considering these limitations, we propose a design paradigm based on incremental optimization of phenotype through a combined computational and experimental approach. We intend this work to be a foundational synthesis of well-known techniques applied to the context of genotype-to-bulk phenotype inverse design, which has not yet been performed in the literature. The design pipeline can optimize phenotype by either directly proposing genotypic changes, or simply by suggesting parents to be used for selective breeding. The soybean nested association matrix data set is used to present an in silico case study of the design pipeline by performing optimization that maximizes protein content while constraining other phenotypes. A random forest (RF) is used to model the genotype-to-phenotype relationship, and a genetic algorithm is used to query the RF until a feasible genotype with desired phenotype is discovered. After 20 in silico DBTL cycles, a final population of individuals with a mean protein content of 36.13%, an increase of three standard deviations above the original mean is suggested.
Completely noninvasive multi-analyte monitoring system for cell culture processes
(Springer, 2024-08-20) Rahmatnejad, Vida; Tolosa, Michael; Ge, Xudong; Rao, Govind
Although online monitoring of dissolved O₂, pH, and dissolved CO₂ is critical in bioprocesses, nearly all existing technologies require some level of direct contact with the cell culture environment, posing risks of contamination. This study addresses the need for an accurate, and completely noninvasive technique for simultaneous measurement of these analytes. A “non-contact” technique for simultaneous monitoring of dissolved O₂, pH, and dissolved CO₂ was developed. Instead of direct contact with the culture media, the measurements were made through permeable membranes via either a sampling port in the culture vessel wall or a flow cell. The efficacy of the “non-contact” technique was validated in Escherichia coli (E.coli), Chinese hamster ovary (CHO) culture processes, and dynamic environments created by sparging gases in cell culture medium. The measurements obtained through the developed techniques were comparable to those obtained through control methods. The noninvasive monitoring system can offer accurate, and contamination-minimized monitoring of critical process parameters including dissolved O₂, pH, and dissolved CO₂. These advancements will enhance the control and optimization of cell culture processes, promising improved cell culture performance.
Impact of Confinement within a Hydrogel Mesh on Protein Thermodynamic Stability and Aggregation Kinetics
(ACS, 2024-01-26) Ghassemi, Zahra; Leach, Jennie B.
Though protein stability and aggregation have been well characterized in dilute solutions, the influence of a confining environment that exists (e.g., in intercellular and tissue spaces and therapeutic formulations) on the protein structure is largely unknown. Herein, the effects of confinement on stability and aggregation were explored for proteins of different sizes, stability, and hydrophobicity when encapsulated in hydrophilic poly(ethylene glycol) hydrogels. Denaturation curves show linear correlations between confinement size (mesh size) and thermodynamic stability, i.e., unfolding free energy and surface area accessible for solvation (represented by m-value). Two clusters of protein types are identifiable from these correlations; the clusters are defined by differences in protein stability, surface area, and aggregation propensity. Proteins with higher stability, larger surface area, and lower aggregation propensity (e.g., lysozyme and myoglobin) are less affected by the confinement imposed by mesh size than proteins with lower stability, smaller surface area, and higher aggregation propensity (e.g., growth hormone and aldehyde dehydrogenase). According to aggregation kinetics measured by thioflavin T fluorescence, confinement in smaller mesh sizes resulted in slower aggregation rates than that in larger mesh sizes. Compared to that in buffer solution, the confinement of a hydrophobic protein (e.g., human insulin) in the hydrogels accelerates protein aggregation. Conversely, the confinement of a hydrophilic protein (e.g., human amylin) in the hydrogels decelerates or prevents aggregation, with the rates of aggregation inversely proportional to mesh size. These findings provide new insights into protein conformational stability in confined microenvironments relevant to various cellular, tissue, and therapeutics scenarios.
POLYCYCLIC AROMATIC HYDROCARBON-INDUCED DISRUPTION OF ENDOTHELIAL PERMEABILITY
(2024-01-01) Patel, Shreyas; Leach, Jennie; Chemical, Biochemical & Environmental Engineering; Engineering, Chemical and Biochemical
Endothelial cells line the interior of vasculature and regulate nutrient exchange while preventing harmful compounds from invading surrounding tissue. Adherens and tight junctions form intercellular junctions that maintain cell-cell adhesion and regulate solute flux between systemic circulation and tissue. These intercellular junctions can be disrupted following exposure to polycyclic aromatic hydrocarbons (PAHs), causing increased permeability in the endothelial barrier. PAHs are ubiquitous pollutants in our surroundings as a consequence of rapid industrialization and heavy reliance on carbon-based fuels. PAH exposure is associated with a myriad of adverse health effects, ranging from skin and eye irritation to cardiovascular disease and cancer. Herein, the permeability of bovine pulmonary artery endothelial cells was examined in vitro following exposure to low molecular weight PAHs. Bovine endothelial barriers demonstrated an average, but not statistically significant, increase in permeability in fluorescein flux assays following exposure to naphthalene, anthracene, and pyrene. The presented data suggests these low molecular weight PAHs can exert an effect on endothelial barrier integrity and function but warrants further optimization to permeability assays and supplemental methods to elucidate the consequences of PAH exposure.
Effects of Inorganic Salts and pH on the Gas-Water Partitioning of Formic Acid and Acetic Acid Observed using Mist Chambers
(2024-01-01) Taylor, Rose; Hennigan, Christopher; Chemical, Biochemical & Environmental Engineering; Engineering, Chemical and Biochemical
Secondary organic aerosol (SOA) is harmful to human health and contributes largeuncertainties to climate forcing. Oxygenated volatile organic compounds (OVOCs), such as carboxylic acids, make significant contributions to SOA by partitioning to atmospheric particulate and aqueous phases. Inorganic salt content and pH of atmospheric water can impact OVOC partitioning and therefore the composition and abundance of SOA. In this work, parallel sampling mist chambers (MC) coupled with wet chemical oxidation(WCO)-based total organic carbon (TOC) analysis is critically evaluated as a method for measuring effects from inorganic salts and pH on formic acid (FA) and acetic acid (AA) gas-water partitioning. High ionic concentrations of chloride (>0.01 mol kg -1 ) and sulfate (>0.1 mol kg -1 ) caused TOC measurement artifacts that required correction. Chloride concentrations characteristic to atmospheric aqueous phases exhibited a salting-out effect on FA and AA partitioning and partitioning to solutions of low pH was reduced. Sulfate did not show a stronginfluence over FA and AA partitioning. Preliminary experiments with glyoxal indicate no effects from chloride and sulfate on partitioning although salting-in effects are reported in literature. Options for further experimentation, validation, and optimization of the MC-WCO method are discussed.
Flux growth of optical sensor zinc selenide crystals
(SPIE, 2024-06-06) Brandt, Meghan; Schmidt, Nicholas; Tauraso, Aria; Sood, Rachit; Su, Ching Hua; Arnold, Bradley; Choa, Fow-Sen; Cullum, Brian; Singh, Narsingh
Binary and ternary selenide crystals have been proven as multifunctional for optical sensors and laser applications. The aim of this study was to evaluate reactive flux growth process of the doped zinc selenide crystals and compared with bulk Physical Vapor Transport (PVT) grown large single crystals. The experimental process of synthesis involved PVP (Polyvinyl Pyrrolidone) flux dissolved in DI water which was heated at 65°C, stirred until all PVP dissolved. We added Se powder dissolved in ethanol and heated again for few minutes. We added ZnCl₂ solution in ethanol/Se mixture and heated at well below 100 ⁰C. Water and ethanol solvent was separated and placed at 200C. The residue material was doped with transition metal. This material was characterized for the luminescence and compared with the results of bulk crystals grown by PVD process.
Exploring connections between auditory hallucinations and language model structures and functions
(SPIE, 2024-06-06) Allen, Janerra D.; Xia, Luke; Hong, L. Elliot; Choa, Fow-Sen
Auditory hallucinations are a hallmark symptom of mental disorders such as schizophrenia, psychosis, and bipolar disorder. The biological basis for auditory perceptions and hallucinations, however, is not well understood. Understanding hallucinations may broadly reflect how our brains work — namely, by making predictions about stimuli and the environments that we navigate. In this work, we would like to use a recently developed language model to help the understanding of auditory hallucinations. Bio-inspired Large Language Models (LLMs) such as Bidirectional Encoder Representations from Transformers (BERT) and Generative Pre-trained Transformer (GPT) can generate next words based on previously generated words from the embedded space and their pre-trained library with or without inputs. The generative nature of neural networks in GPT (like self-attention) can be analogously associated with the neurophysiological sources of hallucinations. Functional imaging studies have revealed that the hyperactivity of the auditory cortex and the disruption between auditory and verbal network activity may underlie auditory hallucinations’ etiology. Key areas involved in auditory processing suggest that regions involved in verbal working memory and language processing are also associated with hallucinations. Auditory hallucinations reflect decreased activity in verbal working memory and language processing regions, including the superior temporal and inferior parietal regions. Parallels between auditory processing and LLM transformer architecture may help to decode brain functions on meaning assignment, contextual embedding, and hallucination mechanisms. Furthermore, an improved understanding of neurophysiological functions and brain architecture would bring us one step closer to creating human-like intelligence.
Lee Blaney Awarded Funding To Develop New Ways To Remove “forever Chemicals” From Water - UMBC
(UMBC News, 2024-05-16) Meyers, Catherine; Demond, Marlayna
Lee Blaney will develop new ways to remove substances dubbed “forever chemicals” from water, with funding from the Department of Defence’s Strategic Environmental Research and Development Program.
Teaching Engineering Economics through Role Play in a Senior Design Class
(ASEE, 2024-04-19) Das, Gautom Kumar
This work-in-progress study analyzes students' performance on a carefully chosen test question over two years, revealing concerning results regarding key learning objectives. The traditional chemical engineering curriculum exposes students to the concepts of engineering economics only during their final year, potentially leading to misconceptions due to limited exposure. To address these issues, a teaching technique was implemented that involved graded in-class problems and role-playing scenarios focused on a ride-share venture. This work outlines the problem, the pattern of the mistakes, and the interventions. Preliminary results indicate some improvement in the test score, suggesting potential effectiveness of the interventions. However, significant further analysis and data collection may be necessary to understand the challenge and offer better solutions.
The impact of nanomaterials in enhancing wastewater treatment processes: A review
(Magna Scientia Advanced Research and Reviews, 2024-02-13) Ugwuanyi, Ejike David; Nwokediegwu, Zamathula Queen Sikhakhane; Dada, Michael Ayorinde; Majemite, Michael Tega; Obaigbena, Alexander
The utilization of nanomaterials in wastewater treatment processes has garnered considerable attention due to their unique physicochemical properties and multifaceted applications. This expanded review delves deeper into the transformative impact of nanomaterials on wastewater treatment processes, offering a comprehensive analysis of recent advancements and emerging trends in the field. Nanomaterials, including nanoparticles, nanocomposites, and nanocatalysts, have demonstrated remarkable efficacy in enhancing pollutant removal efficiency, facilitating resource recovery, and promoting environmental sustainability in wastewater treatment systems. Through a detailed examination of key studies and case examples, this review elucidates the diverse mechanisms by which nanomaterials augment treatment performance, including adsorption, catalysis, and membrane filtration. Moreover, it explores the synergistic effects of integrating nanomaterials with conventional treatment technologies, such as activated sludge processes, membrane bioreactors, and advanced oxidation processes, to achieve superior treatment outcomes. In addition to their efficacy in pollutant removal, nanomaterials offer promising prospects for mitigating emerging contaminants, such as pharmaceuticals, personal care products, and microplastics, which pose significant challenges to traditional treatment methods. However, the widespread adoption of nanomaterial-based technologies in wastewater treatment is not without its challenges and considerations. This review addresses critical issues surrounding the environmental fate and impact of nanomaterials, including their potential ecotoxicological effects, persistence in the environment, and regulatory implications. Furthermore, the review underscores the importance of addressing knowledge gaps and advancing research efforts to optimize the design, synthesis, and application of nanomaterials for sustainable wastewater treatment. Future research directions include the development of eco-friendly synthesis methods, assessment of long-term environmental implications, and integration of nanomaterials into holistic water management strategies. By harnessing the transformative potential of nanomaterials and leveraging interdisciplinary collaborations, the wastewater treatment sector can capitalize on innovative solutions to address the pressing challenges of water pollution and scarcity, fostering a cleaner, healthier, and more sustainable environment for future generations.
Novel design for a microfluidic-based platform for yeast replicative lifespan (RLS) analysis
(Elsevier, 2023-05-13) Kaprou, Georgia D.; Andar, Abhay; Shah, Pranjul; Linster, Carole L.; Paczia, Nicole
Microfluidic devices hold enormous potential for the development of cost-effective and faster alternatives to existing traditional methods across life science applications. Here we demonstrate the feasibility of fabricating a microfluidic device by means of photolithography comprising a single cell trap, a delay structure and a chamber defined by micropillars. This device is aimed to be used for biological applications such as replicative lifespan determination (RLS) of yeast cells, where single cell trapping, and cell counting are essential. The novelty of the present work lies on the integration of the above-mentioned microfluidic structures in a single device by means of the established method of photolithography by fine-tuning critical parameters needed to achieve the desired high aspect ratio (1:5) employing commercially available resins. The fine-tuning of the fabrication parameters in combination with appropriately selected resins allows for patterning reproducibly micron-sized features. The design of the proposed device ultimately aims at replacing the very cumbersome assays still commonly used today for RLS determination in budding yeast by a methodology that is drastically simpler and more time efficient.
Liquid Crystalline Assembly of Collagen for Deterministic Alignment and Spread of Human Schwann Cells
(Royal Society of Chemistry, 2024-11-04) Ghaiedi, Homa; Herrera, Luis Pinzon; Alshafeay, Saja; Harris, Leonard; Almodovar, Jorge; Nayani, Karthik
Collagen is a key component of the extracellular matrix and well-oriented domains of collagen are relevant for mimicking the local cell environment in vitro. While there has been significant attention directed towards the alignment of collagen, formation of large-scale oriented domains remains a key challenge. Type I collagen self-assembles to form liquid crystalline (LC) mesophases in acidic conditions at concentrations above 100 mg/ml. The LC mesophase provides an efficient platform for large-scale alignment and patterning of collagen coated substrates. However, there exist challenges related to solubilizing and processing of collagen at such high concentrations in order to replicate the native extra cellular matrix (ECM). In this contribution, we report on centimeter-scale alignment in collagen-coated glass substrates using solutions that are well below the LC-forming concentrations. Importantly, we are also able to extend this method to create a mimic of the native ECM via macroscopic 3-D collagen hydrogels with programmed anisotropy within them. We explain the formation of these uniform domains via shear-induced and magnetically-induced liquid crystallinity of the collagen solutions. We show that the orientation, spreading and aspect ratio of Human Schwann Cells (HSCs) all are strongly coupled with the alignment of the collagen substrate/hydrogel. We use a simple Metroplis-based model to reveal that a critical magnetic field strength exists for a given concentration of collagen, exceeding which, macroscopic alignment is permissible- enabling guidance for future studies on alignment of collagen at high concentrations.
Giant nanomechanical energy storage capacity in twisted single-walled carbon nanotube ropes
(Nature, 2024-04-16) Utsumi, Shigenori; Ujjain, Sanjeev Kumar; Takahashi, Satoshi; Shimodomae, Ryo; Yamaura, Tae; Okuda, Ryosuke; Kobayashi, Ryuichiro; Takahashi, Oga; Miyazono, Satoshi; Kato, Naoki; Aburamoto, Keiichi; Hosoi, Yuta; Ahuja, Preety; Furuse, Ayumi; Kawamata, Yuma; Otsuka, Hayato; Fujisawa, Kazunori; Hayashi, Takuya; Tománek, David; Kaneko, Katsumi
A sustainable society requires high-energy storage devices characterized by lightness, compactness, a long life and superior safety, surpassing current battery and supercapacitor technologies. Single-walled carbon nanotubes (SWCNTs), which typically exhibit great toughness, have emerged as promising candidates for innovative energy storage solutions. Here we produced SWCNT ropes wrapped in thermoplastic polyurethane elastomers, and demonstrated experimentally that a twisted rope composed of these SWCNTs possesses the remarkable ability to reversibly store nanomechanical energy. Notably, the gravimetric energy density of these twisted ropes reaches up to 2.1 MJ kg⁻¹, exceeding the energy storage capacity of mechanical steel springs by over four orders of magnitude and surpassing advanced lithium-ion batteries by a factor of three. In contrast to chemical and electrochemical energy carriers, the nanomechanical energy stored in a twisted SWCNT rope is safe even in hostile environments. This energy does not deplete over time and is accessible at temperatures ranging from −60 to +100 °C.
Bi-directional neuro-immune dysfunction after chronic experimental brain injury
(Nature, 2024-04-05) Ritzel, Rodney M.; Li, Yun; Jiao, Yun; Doran, Sarah J.; Khan, Niaz; Henry, Rebecca J.; Brunner, Kavitha; Loane, David J.; Faden, Alan I.; Szeto, Gregory L.; Wu, Junfang
Background It is well established that traumatic brain injury (TBI) causes acute and chronic alterations in systemic immune function and that systemic immune changes contribute to posttraumatic neuroinflammation and neurodegeneration. However, how TBI affects bone marrow (BM) hematopoietic stem/progenitor cells chronically and to what extent such changes may negatively impact innate immunity and neurological function has not been examined. Methods To further understand the role of BM cell derivatives on TBI outcome, we generated BM chimeric mice by transplanting BM from chronically injured or sham (i.e., 90 days post-surgery) congenic donor mice into otherwise healthy, age-matched, irradiated CD45.2 C57BL/6 (WT) hosts. Immune changes were evaluated by flow cytometry, multiplex ELISA, and NanoString technology. Moderate-to-severe TBI was induced by controlled cortical impact injury and neurological function was measured using a battery of behavioral tests. Results TBI induced chronic alterations in the transcriptome of BM lineage⁻c-Kit⁺Sca1⁺ (LSK+) cells in C57BL/6 mice, including modified epigenetic and senescence pathways. After 8 weeks of reconstitution, peripheral myeloid cells from TBI→WT mice showed significantly higher oxidative stress levels and reduced phagocytic activity. At eight months after reconstitution, TBI→WT chimeric mice were leukopenic, with continued alterations in phagocytosis and oxidative stress responses, as well as persistent neurological deficits. Gene expression analysis revealed BM-driven changes in neuroinflammation and neuropathology after 8 weeks and 8 months of reconstitution, respectively. Chimeric mice subjected to TBI at 8 weeks and 8 months post-reconstitution showed that longer reconstitution periods (i.e., time post-injury) were associated with increased microgliosis and leukocyte infiltration. Pre-treatment with a senolytic agent, ABT-263, significantly improved behavioral performance of aged C57BL/6 mice at baseline, although it did not attenuate neuroinflammation in the acutely injured brain. Conclusions TBI causes chronic activation and progressive dysfunction of the BM stem/progenitor cell pool, which drives long-term deficits in hematopoiesis, innate immunity, and neurological function, as well as altered sensitivity to subsequent brain injury.

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