It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Designing a heat engine that can produce maximum power at maximum efficiency is a major challenge. Practical heat engines are limited to a theoretical efficiency called the Carnot limit, which sets a cap on how much heat can be converted to useful work. In a breakthrough, researchers at the Indian Institute of Science (IISc) and Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) have devised a novel “micro heat engine” that has overcome this limitation at the lab scale. The study was published in Nature Communications.
“What was considered impossible until today, we have demonstrated that it is possible: achieving both high efficiency and high power simultaneously,” says corresponding author Ajay K Sood, National Science Chair Professor at the Department of Physics, IISc, and Principal Scientific Adviser to the Government of India.
Heat engines convert heat into work – for example, moving a piston in a certain direction. For an engine to be 100% efficient, when the process is reversed – the piston returns to its original state – there should be no heat wasted, which is what was proposed by French physicist Sadi Carnot in 1824. This is only theoretically possible if the process happens extremely slowly, but that also means that the power output will be zero, making the engine practically useless. This is known as the power-efficiency tradeoff.
“Since the 1970s, people have been attempting to address the power-efficiency trade-off. In the early 2000s, researchers explored microscopic systems to overcome this challenge. Interestingly, in 2017, a paper claimed that it was impossible to solve this thermodynamic puzzle,” says Sudeesh Krishnamurthy, former PhD student at the Department of Physics, IISc, and first author of the study.
In the current study, the team mimicked the functioning of a conventional heat engine at the micron scale. Instead of using a mix of gas and fuel, they took a tiny gel-like colloidal bead and used a laser beam to direct its motion, similar to how the piston works in a macroscopic engine.
“Our unique micro-scale engine operates with just one particle,” says Rajesh Ganapathy, Professor at JNCASR and another author. The size of the engine is very small, about 1/100th the width of a single human hair, he adds.
The team also used a rapidly changing electric field to cycle the engine between two states. Under these conditions, they found that the waste heat dissipated drastically reduced, bringing the efficiency close to 95% of the limit specified by Carnot.
“What we have achieved is a reduction in heat distribution time through the introduction of the electric field. This reduction in heat distribution time allows the engine to operate at high efficiency and simultaneously yield a large power output even while operating at high speeds,” says Krishnamurthy.
Previously, the team designed a high-power engine that used a live bacterium to push the particle and power the system. This time, the researchers replaced the bacterium with an electric field to move the particle more efficiently in the colloidal medium and to increase the system's durability.
The results from the experiments show that, under certain conditions, high power can be achieved with high efficiency. Such an advancement could pave the way for more energy efficient devices in the future.
“If one can draw a message from here and try to see how to make a practical interpretation of this micro engine, that is the next part of the story,” emphasises Sood. “We have opened doors that scientists almost gave up opening due to the thermodynamic constraints set by Carnot in previous studies.”
DIANA S-L CHOW, UNIVERSITY OF HOUSTON COLLEGE OF PHARMACY, IS REPORTING THE MEDICINE RILUZOLE, COMMONLY PRESCRIBED FOR ALS, SHOWS POTENTIAL TO HELP PEOPLE REGAIN FUNCTION AFTER ACUTE SPINAL CORD INJURY.
A small clinical trial with a pharmacokinetic sub-study, led by a world-renowned pharmacologist at the University of Houston, has demonstrated the promising effectiveness of the drug Riluzole for improving functionality in people with acute spinal cord injuries (SCI) if the drug is taken within 12 hours post-injury.
Riluzole is among the first drugs to show efficacy for treating acute SCI, which impacts an estimated 18,000 people in the United States each year. The U.S. Food and Drug Administration (FDA) approved the drug in 1995 for the treatment of amyotrophic lateral sclerosis, known as ALS or Lou Gehrig’s Disease, with a daily oral dose of one 50-milligram tablet twice a day. The same dosage regimen was used for this phase 2/3 multi-center clinical trial repurposing the drug for SCI patients. The work is published in the Journal of Neurotrauma.
“Riluzole is a medication that blocks certain sodium channels and is commonly used as an anticonvulsant. However, our studies demonstrate its neuroprotective potential to preserve nerve cells and help people regain some of their lost functions after spinal cord injury,” said lead study author Diana S-L Chow, Paula & John J. Lovoi Sr. Endowed Professor in Drug Discovery and Development and director of the Institute of Drug Education and Research at the UH College of Pharmacy.
Chow cautions that while the results of this study are positive, further investigation is needed given the small number of participants involved in the trial – 32 patients with head and neck injuries were examined.
“The contribution of our investigation is to offer the proof of concept for the drug discovery and development approach for SCI so that the scientific community may facilitate future treatments,” said Chow, noting that Riluzole can be prescribed for “off-label” use by physicians in clinical settings for a different purpose, such as acute SCI. However, it is not for chronic SCI patients to use for purposes other than ALS, before FDA approval.
“These findings have the potential to influence future dosing strategies, ultimately enhancing patient care and improving therapeutic outcomes,” she added.
The acute and progressive nature of traumatic SCI and the complexity of secondary injury alters the pharmacokinetics of therapeutics, namely, how the body processes a drug. For the clinical trial, the researchers developed a model to capture the dynamic nature of the drug’s behavior and patient response, including motor scores in elbow flexors/extensors, wrist extensors and finger flexors/abductors in the upper limbs; hip flexors, knee extensors, ankle dorsiflexors/plantar flexors and a long toe extensor in the lower limbs. All are influenced by the complex pathophysiology of SCI and impacts of the progression of the condition after injury.
“Our research underscores the need for a specific signal in the body that can tell us how well a treatment for spinal cord injuries works. In our study, we used an SCI-specific biomarker called phosphorylated neurofilament-heavy subunit (pNF-H) to show how Riluzole helps reduce neuron cell damage in SCI. Our findings revealed that patients who received the treatment had lower levels of pNF-H, confirming the positive effect of the medication on spinal cord injuries,” said Chow.
Chow is an internationally recognized expert in the development and analyses of new drug formulations and drug-delivery systems for the treatment of leukemia, other cancers and infection. She has also studied the stability and efficacy of medications used in space flights on the International Space Station.
This most recent study also established a link between short-term outcomes, such as pNF-H concentration, and long-term improvements in functional motor abilities. “This connection suggests the feasibility of predicting if a patient will benefit from the treatment with long-term functional improvements early in the treatment process at the bedside through the objective biomarker measurement,” she added.
Other members of the research team include Ashley Nguyen, a recent UH graduate and clinical pharmacologist at Janssen, Johnson & Johnson; Junghwa Park, PharmD and doctoral student; and Lei Wu, previous research assistant professor and current associate director in clinical pharmacology of AbbVie pharmaceutical company; Elizabeth Gardiner Troups, Houston Methodist Research Institute; James Shields Harrop, Thomas Jefferson University; James David Guest, University of Miami; Karl Michael Schmitt, UTHealth Houston; Bizhan Aarabi, University of Maryland; Michael George Fehlings, University of Toronto; Maxwell Boakye, University of Louisville; and late Robert Geroge Grossman, Houston Methodist Research Institute.
The material in Chow’s report is based upon work supported by the U.S. Army Medical Research Acquisition Activity, the Christopher & Dana Reeve Foundation, with supplemental funding by the Institute for Drug Education and Research (IDER) of the UH College of Pharmacy.
JOURNAL
Journal of Neurotrauma
ARTICLE TITLE
Patients With Traumatic Cervical Spinal Cord Injury Enrolled in the RISCIS Phase III Randomized Controlled Trial
Researchers demonstrate novel technique to observe molten salt intrusion in nuclear-grade graphite
FROM LEFT, YUXUAN ZHANG, JAMES KEISER, JISUE MOON, CRISTIAN CONTESCU, ERIK STRINGFELLOW (BACK) AND NIDIA GALLEGO, WITH DINO SULEJMANOVIC (NOT SHOWN), FIRST VISUALIZED MOLTEN SALT DISTRIBUTION IN GRAPHITE PORES.
In response to a renewed international interest in molten salt reactors, researchers from the Department of Energy’s Oak Ridge National Laboratory have developed a novel technique to visualize molten salt intrusion in graphite.
During ORNL’s revolutionary Molten Salt Reactor Experiment, or MSRE, in the 1960s, scientists first demonstrated the feasibility of nuclear fission reactions with molten fluoride salt used both as a fuel carrier and as a coolant, substituting for the solid fuel and water used in traditional nuclear reactors. Molten salt reactor designs show great promise as a means of carbon-free power generation.
To slow down neutrons so they can easily promote nuclear fission, nuclear reactors use a material called a moderator. To moderate the MSRE, scientists used synthetic graphite, which is resistant to thermal shock and dimensionally stable because of its extensive pore system resulting from the manufacturing process. MSRE graphite was custom-made and specially coated to decrease porosity and defend against detrimental effects that may occur when hydraulic and gas pressures cause molten salt to seep into graphite’s pores. Moreover, preventing molten salt intrusion avoids additional issues with waste management during reactor decommissioning.
Following the conclusion of ORNL’s experiment in 1969, the potential of molten salt reactors was largely unexplored until the 21st century, and low demand for the specialized graphite led to the material’s discontinuation among domestic graphite manufacturers. With an uptick in molten salt reactor research but no MSRE graphite, today’s scientists must identify an alternative graphite to successfully moderate nuclear reactions in molten salts. However, ambiguity around the effects of molten salt intrusion poses a barrier to discovery. Scientists have a limited understanding of what microscopic features enable some graphite grades to withstand intrusion better than others and how salt intrusion affects graphite’s other properties.
Hoping to resolve these uncertainties, a team of ORNL scientists led by Nidia Gallego and Jisue Moon studied molten salt intrusion across various graphite grades and have validated the first technique to visualize and monitor molten salt penetration depth and distribution in graphite’s pores.
“It’s critical for us as materials scientists to help test and develop techniques that we can use or have a better perspective on what we need to do to understand how the salt that goes into the pores may affect the mechanical or the thermal properties of the graphite,” said Gallego, a distinguished R&D staff scientist in ORNL’s Chemical Sciences Division.
Traditionally, scientists measure salt intrusion by weighing graphite before and after exposure to molten salt. ORNL researchers hoped to gain a more detailed understanding of intrusion by actually looking at what happens inside the graphite.
Gallego and Moon, an R&D associate scientist in the Radioisotope Science and Technology Division, first tried X-ray tomography to evaluate salt intrusion, but the time-consuming method required smaller sample sizes and could not provide enough contrast for a close look inside graphite’s pores.
The team moved on to neutron imaging, which is suitable for large-volume sample sizes.
Molten salt intrusion in graphite varied across graphite grades. In medium-fine graphite, which has larger pores than superfine graphite, salt penetrated deeper into the material.
CREDIT
Yuxuan Zhang, Nidia Gallego, Jisue Moon/ORNL, U.S. Dept. of Energy
Using neutron imaging at HFIR’s MARS instrument, scientists observed and reconstructed molten salt intrusion in graphite.
CREDIT
Carlos Jones/ORNL, U.S. Dept. of Energy
Nidia Gallego and Jisue Moon developed a novel technique to observe molten salt intrusion in nuclear-grade graphite and published their findings in Carbon.
CREDIT
Carlos Jones/ORNL, U.S. Dept. of Energy
“Before we started using neutron imaging, we had to destroy the sample to visualize salt intrusion using microscopy techniques,” Moon said. “However, with neutron imaging, we can do a three-dimensional computed tomography scan of the whole sample to visualize the salt distribution, and then we can perform additional analysis as needed.”
Using the Multimodal Advanced Radiography Station instrument at the High Flux Isotope Reactor, or HFIR, a DOE Office of Science user facility at ORNL, the researchers achieved the first 3D, direct visualization of molten salt distribution in graphite pores, a novel accomplishment.
In neutron imaging, neutron attenuation coefficients, which describe how a neutron beam is reduced as it passes through a material, vary greatly between graphite and fluoride salt. This difference created a strong visual contrast between the materials that researchers observed when reconstructing sections of the graphite.
“Neutron imaging is perfect because it really allows us to visualize where the salt is going,” Gallego said.
Using the 3D reconstructions, Gallego and Moon compared molten salt penetration in graphite’s pores across grades of varying particle size. Under the specific pressure and temperature conditions used in the salt exposure experiments, researchers determined that in most superfine grain graphites, penetration was nonuniform, limited to the first few millimeters below the graphite’s surface and localized around the perimeter of the sample cross section. In medium-fine-grain graphite, which has larger pores than superfine graphite, the salt penetrated deeper into the material and fully covered the area of the sample cross section.
The team ultimately identified graphite microstructure, which describes the size and distribution of pores, as the most important factor in determining molten salt penetration and density distribution for a given temperature and pressure.
“Molten salt intrusion could significantly affect the operation of molten salt reactors,” Moon said. “This research can help us see the impact of the salt in the graphite materials and thus can help us develop more standardized methods to design the proper graphite.”
After publishing their findings in Carbon, Gallego and Moon are continuing research with HFIR scientists to improve neutron imaging resolution and observe molten salt intrusion with additional temperature, pressure and time variables.
“There’s a lot from the technique perspective, a lot of improvements, developments that are possible and are of interest to the scientists that will also give us a lot of insight into the dynamics and the kinetics of the process,” Gallego said.
Ultimately, the team hopes to develop predictive models to describe how different graphite grades respond to salt intrusion and refine molten salt reactor operating standards, which denote material and technical requirements for reactors but lack specification about preferred graphite grades.
“Understanding how the graphite interacts with the salt is critical,” Gallego said.
Additional researchers who contributed to the project include ORNL’s Cristian I. Contescu, James R. Keiser, Dino Sulejmanovic, Yuxuan Zhang and Erik Stringfellow.
The DOE Office of Nuclear Energy supported the work through the Advanced Reactor Technologies Program.
UT-Battelle manages ORNL for DOE’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science. — Alexandra DeMarco
CREDIT: CELL REPORTS PHYSICAL SCIENCE/YAZDAN PARAST ET AL.
Sperm can modulate their energetics by regulating their flagellar waveform—how the sperm oscillate their tails—in order to adapt to varying fluid environments, potentially optimizing their motility and navigation within the reproductive tract. This research is reported in a study publishing November 1in the journal Cell Reports Physical Science.
“Our approach allowed us to investigate how variations in viscosity and shear rates affect sperm behavior at the single-cell level, which was not possible using traditional methods,” says senior study author Reza Nosrati of Monash University.
Biochemical and biophysical cues within the reproductive tract serve as filters against low-quality sperm and guidance mechanisms for high-quality sperm to navigate toward the egg. For example, during sexual intercourse, intensified mucus secretions within the oviduct stimulate fluid movement in the fallopian tube toward the uterus. This flow helps prevent pathogens from invading the reproductive tract by flushing them down and simultaneously selects sperm capable of swimming against the flow toward the egg via a phenomenon known as rheotaxis.
But due in part to the limitations of conventional microscopy methods and population-level studies, it has remained unclear how factors like fluid flow and viscosity interact to influence sperm flagellar beating behavior at the single-cell level. Moreover, current clinical practices largely utilize low-viscosity media and stagnant flow conditions, even though the practical advantages of considering physiologically relevant environments might be significant.
In this study, Nosrati and his team designed a “testing arena” for the sperm to observe their behavior under physiologically relevant conditions. This device leveraged microfluidics to examine sperm flagellar waveform and energetics in response to changes in flow and viscosity. By tethering bull sperm in a microchannel, the researchers exposed the same individual sperm to a range of viscosities and shear rates, which refer to the rates of change in velocity at which one layer of fluid passes over an adjacent layer. Using high-speed, high-resolution microscopy, the researchers quantified flagellar dynamics at 200 frames per second.
The findings showed that sperm flagellar waveforms are primarily influenced by viscosity rather than the shear rate, and their synergistic effect promotes energy-efficient beating behavior. The motility and energetics of sperm were less influenced by fluid flow in environments with lower viscosities. But in high-viscosity media, an increase in shear rate from 0 to 6 per second at 75 millipascal seconds reduced the flagellar curvature by 20%, and the flagellar beating frequency was highest at a shear rate of 3 per second, which is favorable for sperm rheotaxis.
According to the authors, this phenomenon suggests a potential increase in energy production and changes in flagellar beating behavior under these specific conditions to possibly enable rheotaxis and facilitate a transition from circular motion to rolling motion. This increased energetic output observed at a shear rate of 3 per second suggests that the sperm adjusts its power generation to adapt and respond to the fluid dynamics, thereby enabling efficient swimming against the flow.
Currently, the researchers are refining their imaging techniques and experimental platform for a follow-up study to examine free-swimming sperm under similar conditions. “It’s also crucial to better understand the importance of these media considerations with respect to sperm selection and fertilization,” Nosrati says. “We plan to run an animal study to evaluate how such properties can influence fertilization and embryo development in assisted reproduction to inform future treatment strategies for better outcomes.”
Experimental setup for analysing sperm flagellar dynamics at the single-cell level
Dark-field microscopy of individual sperm at 200 frames per second with varying viscosities and shear rates (Scale bar is 20 micron)
CREDIT
Cell Reports Physical Science/Yazdan Parast et al.
This work was supported by the Australian Research Council (ARC) Discovery Project, the Australian National Health and Medical Research Council, and Monash University.
Cell Reports Physical Science (@CellRepPhysSci), published by Cell Press, is a broad-scope, open access journal that publishes cutting-edge research across the spectrum of the physical sciences, including chemistry, physics, materials science, energy science, engineering, and related interdisciplinary work. Visit https://www.cell.com/cell-reports-physical-science/home. To receive Cell Press media alerts, please contact press@cell.com.
PHILADELPHIA (November 1, 2023) – Many people overlook the short- and long-term costs of financial caregiving, a growing problem that financial advisors and employers can help address, according to a new report by the TIAA Institute and the University of Pennsylvania School of Nursing (Penn Nursing).
One in five adults now provide uncompensated care to loved ones with health problems, and the report provides a comprehensive compilation of insights and research that underscores how the caregivers face a series of financial and professional challenges. On average, the caregivers’ uncompensated expenses – things like housing, healthcare, and transportation – add up to more than $7,000 a year, pushing almost half of them to say they’ve suffered financially. Many feel they have no choice but to withdraw money from savings accounts or retirement nest eggs, take on debt, pay bills late or scale back on their retirement contributions.
The impact also extends into the workplace. Caregiving typically requires 24 hours a week, and about 60% of caregivers have jobs outside the home. As a result, 61% of those caregivers reported at least one work-related consequence, such as arriving late, leaving early, taking time off or retiring sooner than planned.
“Although the emotional and physical toll on family caregivers is well recognized, the financial impact of these roles has received less attention,” said Surya Kolluri, Head of the TIAA Institute. “The impact on lifetime earnings, savings, Social Security benefits and retirement readiness can be severe. Especially today, as people are living longer, caregivers should plan for these costs at various life stages.”
The report comes as the need for caregivers will likely skyrocket. Each day, about 10,000 Baby Boomers turn 65, and they’re living longer than ever. Life expectancy has risen by 17 years since the Social Security program debuted in 1935. The new report also reveals that caregivers have lower levels of financial assets and higher levels of debt compared to those who don’t care for loved ones. One in four caregivers has less than $1,000 in savings and investments, for example. For non-caregivers, the number was closer to one in seven.
The financial burdens of caregiving are often steeper for both women and millennials. Women already have 30% less income than men during retirement, and a disproportionate number of caregivers (60%) are women. In addition, about 25% of the caregivers are in their twenties or thirties. Becoming a caregiver at a young age is especially difficult, because it’s a time when people often have smaller salaries and should be taking the biggest strides in their careers. Many people that age are also raising children, making them part of the so-called “sandwich” generation, which creates even more emotional and financial burdens.
“As younger generations increasingly take on caregiving roles, they face different financial pressures and trade-offs,” said Mary Naylor, PhD, Director of Penn Nursing’s NewCourtland Center for Transitions and Health. “The financial choices made at younger ages have ripples for years to come, as families weigh the relative importance of present spending, saving for large expenses and saving for retirement.”
The new report outlines several ways financial advisors and employers can support caregivers as they cope with their emotions, their finances, and their careers. Financial advisors, for instance, should take a more holistic view of the way they help clients. It’s no longer about simply building a nest egg for retirement. It’s about working with a family to prepare for the emotional, physical, and financial burden of a longer life span, the risks and caregiving issues that could occur at any point and the short- and long-term tradeoffs that come with different decisions.
Financial advisors should also form relationships with social workers, human resource managers or other professionals to make connections when helpful. And they can take professional development courses to meet the new challenges. AgeLab at MIT, for instance, has created a “Preparing for Longevity Advisory Network” of financial advisors and other retirement planners to develop new ideas and ways of thinking about longevity planning, including caregiving, aging in place, work and technology.
There are also several ways employers can support working caregivers, such as:
Help employees navigate challenging caregiving situations by sharing tools like the Caregiving Intensity Index. It’s a two-minute self-assessment that measures how caregiving is affecting someone’s well-being and how they’re coping with potential stressors, including money or family disagreements. It’s already being used by several employers, as well as state governments in New York and Massachusetts.
Add benefits, such as flextime, paid family leave, geriatric care management services and emergency backup care.
Offer services that help people understand how to avoid running out of income during retirement. Encourage them to make sure their financial plans include the possibility of time off and extra expenses related to caregiving.
Create employee networks or caregiver resource groups so employees learn from each other about how to create a better work-life balance.
For employees, the report recommends meeting with financial advisors to better understand life expectancy and how to plan accordingly. “Health and wealth are increasingly two sides of the same coin,” Kolluri said. “The traditional role of a financial advisor needs to shift from retirement planning to a more holistic model that includes considerations such as longevity, health, family, finances, caregiving and, indeed, financial caregiving.”
The TIAA Institute, the research arm of TIAA, helps advance the ways individuals and institutions plan for financial security and organizational effectiveness. The institute conducts in-depth research, provides access to a network of thought leaders, and enables those it serves to anticipate trends, plan future strategies and maximize opportunities for success. For more information about the TIAA Institute, visit www.tiaainstitute.org.
About TIAA
TIAA is a leading provider of secure retirements and outcome-focused investment solutions to millions of people and thousands of institutions. It is the #1 not-for-profit retirement market provider[1], paid more than $5.6 billion in lifetime income to retired clients in 2022 and has $1.3 trillion in assets under management (as of 6/30/2023)[2].
About the NewCourtland Center at the University of Pennsylvania School of Nursing
The mission of the NewCourtland Center at the University of Pennsylvania School of Nursing is to influence, via rigorous evidence, practices and policies designed to enhance transitions in health and healthcare, improve health and quality of life outcomes and promote wiser use of resources for the growing population of chronically ill adults in the United States and globally. Specifically, the NewCourtland Center generates, disseminates and translates multidisciplinary research related to nursing’s influence on major health transitions for this vulnerable population and their family caregivers. Simultaneously, the Center prepares the next generation of scholars from nursing and other disciplines to pursue this significant agenda by providing leadership in advancing knowledge essential to solve society’s most complex health and social issues. For more information, visit www.nursing.upenn.edu/ncth/
About the University of Pennsylvania School of Nursing
The University of Pennsylvania School of Nursing is one of the world’s leading schools of nursing. For the eighth year in a row, it is ranked the #1nursing school in the world by QS University. For the third year in a row, our Bachelor of Science in Nursing (BSN) program is ranked # 1 in the 2024 U.S. News & World Report’s Best Colleges rankings. Penn Nursing is also consistently ranked highly in the U.S. News & World Report annual list of best graduate schools and is ranked as one of the top schools of nursing in funding from the National Institutes of Health. Penn Nursing prepares nurse scientists and nurse leaders to meet the health needs of a global society through innovation in research, education, and practice. Follow Penn Nursing on: Facebook, Twitter, LinkedIn, & Instagram.
