Science Society

Today we welcome Dr. Zi-Kui Liu, a distinguished figure in the realm of Materials Science. With a career spanning decades and encompassing education, research, leadership, and entrepreneurship, Dr. Liu has made significant contributions to our understanding of materials and their properties.

Dr. Zi-Kui Liu's Journey:

Dr. Liu's academic journey took him from Central South University to University of Science and Technology Beijing, culminating with a PhD from the Royal Institute of Technology, Sweden. His professional career has seen him take on roles at University of Wisconsin-Madison, Questek Innovation, LLC, and a longstanding association with The Pennsylvania State University. A pioneer in the field, Dr. Liu coined the term “Materials Genome®” in 2002 and founded several institutions that further materials science research and application.

Recognitions and Achievements:

Dr. Liu's work has been widely recognized with numerous awards and positions of leadership in renowned international institutions like ASM International and TMS.

Focus of Research:

His research revolves around the fusion of quantum, statistical, and irreversible thermodynamics to predict and model material properties.

Particularly intriguing is the zentropy theory, a groundbreaking approach developed by Dr. Liu and his team.

Zentropy Theory Explained:

The theory emerged from an observation: certain materials shrink as they heat, a phenomenon that was previously not entirely understood.

Using thermodynamic relations, the zentropy theory provides a comprehensive understanding of why volume sometimes decreases with temperature increase.

This theory explains that high-temperature phases are statistical representations of various configurations—both stable and metastable. When certain configurations with high probabilities occupy smaller volumes than the ground-state configuration, the material's volume can decrease with rising temperature.

The zentropy theory also has broader applications, potentially helping to predict anomalies in other physical properties of phases.

Case Studies:

Dr. Liu provides real-world examples, highlighting the behavior of materials like Ce and Fe3Pt. These examples showcase the temperature and pressure combinations that can lead to either positive or negative thermal expansions.

Conclusion:

Dr. Zi-Kui Liu's zentropy theory offers a groundbreaking perspective on understanding the sometimes counterintuitive behaviors of materials. By identifying and predicting these anomalies, scientists and engineers can potentially harness these properties for innovative applications in technology and industry.

We extend our gratitude to Dr. Liu for sharing his invaluable insights. Stay connected for more episodes where we uncover the mysteries of the material world.

http://dx.doi.org/10.1007/s11669-022-00942-z

In this intriguing episode with Dr. Danilo Bzdok, we delve deep into how psychedelics potentially influence our consciousness by altering the way our higher association cortex processes sensory signals. By examining 6,850 testimonials on 27 different drugs and comparing them against 40 neurotransmitter receptor subtypes, Dr. Bzdok paints a comprehensive picture of the connection between drug-induced changes in awareness and their corresponding locations in the brain. The result? An innovative approach that highlights how our experiences with these substances relate to the balance between higher-level association and sensory input. Discover how the intricate dance between language, the brain, and consciousness can shed light on the effects of various psychoactive molecules.

Keywords:

Psychedelics

Consciousness

Higher association cortex

Sensory signals

Testimonials

Neurotransmitter receptor subtypes

Drug-induced changes

Receptor density proxies

Large-scale networks

Natural language descriptions

Semantic structure

Brain mapping.

https://doi.org/10.1126/sciadv.abl6989

In an engaging conversation with Dr. Titas Sengupta, we delve into the intricate processes guiding the placement of neurites in specific neural layers during brain development. Utilizing groundbreaking imaging techniques and advanced quantitative models, Dr. Sengupta unveils his findings on the embryonic development of the C. elegans brain neuropil. At the core of this exploration lies the profound role of differential adhesion, orchestrated by the interaction between IgCAM SYG-1 and its ligand partner, SYG-2. Rather than the anticipated outgrowth method, neurites are found to employ a unique "retrograde zippering" mechanism, which governs their precise placement. Through this study, Dr. Sengupta bridges the realm of biophysics with neural development, offering fresh perspectives on how synaptic specificity is achieved in the developing brain.

Keywords:

Neurites

Synaptic specificity

C. elegans brain neuropil

Differential adhesion

IgCAM SYG-1

SYG-2

Retrograde zippering

Neural development

Circuit formation

Biophysical principles

Neurite placement.

https://doi.org/10.7554/eLife.71171.sa0

In a captivating conversation with Dr. Habchi and Dr. Jawed, we take a deep dive into the enigmatic world of spider ballooning. Using state-of-the-art three-dimensional numerical simulations and the discrete elastic rods method, they explore the hypothesis that spiders' ballooning mechanism is influenced by the electric charge dynamics between spider silk threads and the Earth's atmospheric electric potential. Validated with experimental data, their research examines two unique cases of electric charge distribution: uniformly spread across the threads and concentrated at the thread tip. Intriguing findings reveal how terminal ballooning velocity is affected differently in both cases, with a striking observation of a three-dimensional conical sheet formed due to the threads' electric charges preventing entanglement. This episode is an enlightening journey into the interplay of biology, physics, and nature's unmatched engineering prowess.

Keywords:

Spider ballooning

Three-dimensional simulations

Discrete elastic rods method

Electric charge

Earth's atmosphere

Terminal ballooning velocity

Elastic bending stiffness

Viscous forces

Coulomb repelling forces

Thread entanglement.

https://doi.org/10.1103/PhysRevE.105.034401

In this enlightening episode with Dr. Keqiang Ye, we journey into the fascinating connection between Alzheimer's disease and rising levels of follicle-stimulating hormone (FSH) in the body, particularly during the menopausal transition. With alarming evidence suggesting an accelerated cognitive decline in older women, Dr. Ye reveals groundbreaking research that shows FSH’s direct influence on neurons, contributing to the development of Alzheimer’s. Interestingly, blocking FSH’s action shows not only potential in treating Alzheimer’s but also other conditions like obesity, osteoporosis, and dyslipidaemia. As we move away from traditional beliefs about pituitary glycoproteins and acknowledge their broader influences on our system, the episode sheds light on exciting possibilities for innovative treatments targeting multiple conditions simultaneously.

Keywords:

Alzheimer’s disease

Follicle-stimulating hormone (FSH)

Menopausal transition

Cognitive decline

Neuronal C/EBPβ–δ-secretase pathway

Osteoporosis

Obesity

Dyslipidaemia

Treatment

Pituitary glycoproteins

Bone mass

FSH-blocking agent.

https://doi.org/10.1038/s41586-022-04463-0

In the episode featuring Dr. Priyadarshini, the spotlight is on the innovative use of single-guide Piwi-interacting RNAs (piRNAs) to guide the piRNA pathway for specific gene silencing in the Caenorhabditis elegans organism, which encompasses the hermaphrodite germline, sperm, and embryos. Termed as piRNA-mediated interference (piRNAi), this method presents a more efficient and scalable approach than traditional RNAi. A unique characteristic of piRNAi is its ability for conditional gene silencing and induction of transgenerational epigenetic silencing, suggesting its potential for in-depth studies on transgenerational inheritance. When benchmarked against other gene-silencing methods, piRNAi stands out for its programmability and efficiency. However, it's not without limitations, such as its germline-specific expression and the need for transgene injections. Yet, Dr. Priyadarshini emphasizes the vast potential of piRNAi, especially in the context of exploring the realms of piRNA biology and epigenetic silencing.

Keywords:

piRNAi

Gene silencing

Caenorhabditis elegans

Transgenerational epigenetic silencing

PRG-1

RNAi

Epigenetic

Germ-line

Endogenous genes

CRISPR interference (CRISPRi).

https://doi.org/10.1038/s41592-021-01369-z

Novel Strategy to Tackle Antibiotic Resistance: Dr. Mavridou's research presents a novel approach to combat antibiotic resistance. By targeting a single non-essential bacterial protein, DsbA, the team was able to inhibit multiple antibiotic resistance (AMR) determinants.

DsbA and its Role: DsbA, a protein unique to bacteria, plays a significant role in the function of various resistance enzymes. By inhibiting this protein, the research team managed to sensitize certain pathogens to existing antibiotics, making those drugs effective once again.

β-lactamase Enzymes and DsbA: A significant focus was placed on β-lactamase enzymes, which confer resistance to a range of antibiotics. By targeting DsbA, these enzymes were incapacitated, especially those that aren't affected by classical β-lactamase inhibitors. This is especially relevant as many clinically important pathogens possess these enzymes.

MCR Enzymes and Colistin Resistance: The rise of MCR enzymes has made the antibiotic colistin, often a last-resort drug, less effective. However, since MCR enzymes contain multiple disulfide bonds, inhibiting the DSB system could reverse this resistance.

Efflux Pump Inhibitors: There's a notable absence of clinically viable efflux pump inhibitors. While the impact of DsbA on efflux pumps was modest, the relationship between DsbA and pump function was underscored, pointing towards future areas of exploration.

Potential of Cell Envelope Proteostasis: The bacterial cell envelope's protein management system has significant untapped potential. The DSB system, once considered merely a maintenance system, is crucial for bacterial adaptation. It's essential for virulence, plays a role in the life cycle of bacterial persister cells, and, crucially, is vital for bacterial survival against antibiotics.

Clinical Implications: The study showcases the potential of targeting bacterial proteostasis pathways. Inhibiting such systems in pathogens could lead to more effective treatment methods that neutralize AMR determinants and disarm virulence factors.

Conclusion: Dr. Mavridou's research offers a groundbreaking approach to countering antibiotic resistance. By understanding and targeting bacterial proteostasis, especially the DSB system, there's potential to develop novel therapeutic strategies, reinvigorate the efficacy of existing antibiotics, and provide a framework for future antibiotic research.

https://doi.org/10.7554/eLife.57974

Dr. Cunningham's findings throw fresh light on the enigmatic heavy-element pollution in white dwarf atmospheres. With the direct evidence from X-rays and the newly deduced accretion rates, the research reshapes our understanding of the processes at play in these ancient stellar remnants and suggests a need for refined models to fully capture the complexities unfolding in these stars.

White Dwarf Pollution: A significant number of white dwarf stars possess atmospheres tainted by heavy elements. These elements, intriguingly, should vanish from sight in a relatively short time due to gravitational settling.

Accretion Hypothesis: The presence of these heavy elements has long been thought to signify ongoing accretion (a process where matter accumulates onto a central body) of debris, possibly remnants of asteroids, comets, or even large planets. This theory gains strength from certain observations of debris discs and transiting planetary fragments near some white dwarfs.

Indirect Evidence: While these metals in a white dwarf's atmosphere hint towards accretion, they don't provide direct evidence. Relying on them to infer accretion rates or deduce the composition of the debris has its challenges and heavily leans on models of how these elements move and mix within the white dwarf's atmosphere.

X-ray Discovery from G29–38: Dr. Cunningham's breakthrough was the notable detection of X-rays emanating from a metal-polluted white dwarf named G29–38. This discovery allows for a more direct measure of the accretion rate, which turns out to be independent of the atmospheric models previously relied upon.

Accretion Rate: From these X-ray observations, they determined an instantaneous accretion rate. This rate surpasses previous estimations based on studying the white dwarf's surface heavy element concentrations.

Implications for Modelling: The higher-than-expected accretion rate might indicate that there's more happening beneath the visible layers of the white dwarf than currently understood. The mention of "convective overshoot" suggests that models may need to account for more vigorous mixing processes.

Low Plasma Temperature: They recorded a plasma temperature of around

0.5 ±0.2 keV 0.5±0.2keV, which backs up a theory suggesting that white dwarfs with low accretion rates are bombarded by incoming debris.

https://doi.org/10.1038/s41586-021-04300-w

Endocytic Clathrin Coats and Curvature: The episode kicks off with an introduction to endocytic clathrin coats. These are structures that form on a cell's surface to help internalize extracellular molecules. An essential step in this process involves curving a flat piece of the cell membrane into a vesicle, which the endocytosis machinery facilitates.

Initial Findings: Contrary to previous beliefs, the formation of clathrin pits doesn't depend on a late-stage flat-to-curved transition. The curvature actually starts developing from the early stages of their formation. This revelation challenges existing models of clathrin coat formation. Additionally, membrane tension, or the tautness of the cell surface, doesn't seem to affect how these clathrin pits generate curvature.

Use of Super-Resolved Imaging: Dr. Cocucci’s team employed advanced, super-resolved live cell fluorescence imaging to monitor clathrin-coated pit formation in real-time. This technique allowed them to observe these processes in both cultured cells and tissues of developing organisms with unparalleled clarity.

Flat-to-Curved Transition Models: Such models hypothesized that significant changes in clathrin coat structure were needed for vesicle formation. These changes would involve substantial alterations in the size (or "footprint") and brightness of the clathrin structures before domes and pits could form. However, Dr. Cocucci's observations challenge this idea. While they don't deny the possibility of such transitions, their data suggest a continuous curvature generation process from the outset of clathrin pit formation without any late-stage drastic transitions.

Role of CALM Adaptors: An intriguing observation was the distinct clustering of CALM adaptors beneath clathrin structures, while another protein, AP2, distributed more evenly. CALM is known to play a role in both detecting and driving curvature. The team proposes that these CALM clusters could increase local strain on the clathrin structures, potentially causing them to break and complete pit formation, especially at the edges.

Dr. Cocucci's groundbreaking work, backed by high-resolution imaging, offers a revised understanding of how clathrin-coated pits form and generate curvature on the cell membrane. By highlighting the early onset of curvature and the unique roles of CALM adaptors, this study has significant implications for our grasp of endocytosis and cell biology as a whole.

https://doi.org/10.1016/j.devcel.2021.10.019

Complex Nature of Vocal Pitch: Dr. Rhee reiterates that vocal pitch isn't just about the F0 (fundamental frequency). It encompasses both F0 and other acoustic cues, which are crucial for linguistic understanding.

Musicality and Pitch in Language Development: Recent studies suggest that musicality influences how learners develop pitch perception in sentence intonation and prosodic emphasis. Dr. Rhee’s research delves deep into this relationship, focusing on Mandarin—a tonal language.

Research Methodology: 43 Mandarin-speaking children (ages 4 to 6) were tested on tone production and musicality. The study measured how contrasting their tones were across age and musicality levels using acoustic cues.

Pitch Development Findings: While primary F0 cues show a gradual development from ages 3-8, the cues using spectral components or their integration with F0 show a more delayed progression. Notably, blending F0 and spectral cues doesn't significantly enhance tone contrast until age 6.

Musicality’s Influence on Pitch Development: Higher musicality boosts tone contrast in children aged 4 and 5, irrespective of pitch cue type. By age 6, this advantage dwindles, aligning with findings from other studies. Dr. Rhee posits that younger kids, who are still refining their vocal pitch control, might be more influenced by auditory feedback. This is where musicality, or pitch perception ability, could play a pivotal role in their tone production.

Considerations and Limitations: Dr. Rhee acknowledges potential pitfalls. The study's relatively small sample size, especially in the 4-5 age bracket, might not capture the full spectrum of development. Continuous variables like age and musicality were grouped into categories. Also, the study assessed musicality from a perceptual angle and linguistic pitch cues only in production, hinting at the need for a more holistic research approach in the future.

Conclusion: In a groundbreaking exploration, Dr. Rhee unravels the intricate web connecting musicality and linguistic pitch cue development. Young Mandarin-speaking kids with better musicality show accelerated lexical tone production growth. Given the importance of pitch in tonal languages, this discovery is monumental. Future studies are anticipated to expand on these insights, offering a more comprehensive view of musicality's role across various linguistic structures and languages.

https://doi.org/10.3389/fnins.2022.804042