Scientists from the Sainsbury Laboratory at Cambridge University and Jagiellonian University,Poland made the discovery while undertaking an evolutionary survey of the microscopic structure of wood from some of the world’s most iconic trees and shrubs.?They found that Tulip Trees,which are related to magnolias and can grow over 30 metres(100 feet)tall,have aunique type of wood.This discovery may explain why the trees,which diverged from magnolias when earth‘s atmospheric CO2 concentrations were relatively low,grow so tall and so fast.This opens new opportunities to improve carbon capture and storage in plantation forests by planting afast-growing tree more commonly seen in ornamental gardens,or breeding Tulip Tree-like wood into other tree species.The discovery was part of an evolutionary survey of the microscopic structure of wood from 33 tree species from the Cambridge University Botanic Garden’s Living Collections.The survey explored how wood ultrastructure evolved across softwoods(gymnosperms such as pines and conifers)and hardwoods(angiosperms including oak,ash,birch,and eucalypts).?The wood samples were collected from trees in the Botanic Garden in coordination with its Collections Coordinator.Fresh samples of wood,deposited in the previous spring growing season,were collected from aselection of trees to reflect the evolutionary history of gymnosperm and angiosperm populations as they diverged and evolved.?Using the Sainsbury Laboratory‘s low temperature scanning electron microscope(cryo-SEM),the team imaged and measured the size of the nanoscale architecture of secondary cell walls(wood)in their native hydrated state.Microscopy Core Facility Manager at the Sainsbury Laboratory,Dr Raymond Wightman,said:“We analysed some of the world’s most iconic trees like the Coast Redwood,Wollemi Pine and so-called‘living fossils‘such as?Amborella trichopoda,which is the sole surviving species of afamily of plants that was the earliest still existing group to evolve separately from all other flowering plants.“Our survey data has given us new insights into the evolutionary relationships between wood nanostructure and the cell wall composition,which differs across the lineages of angiosperm and gymnosperm plants.Angiosperm cell walls possess characteristic narrower elementary units,called macrofibrils,compared to gymnosperms.”?The researchers found the two surviving species of the ancient Liriodendron genus,commonly known as the Tulip Tree(Liriodendron tulipifera)and Chinese Tulip Tree(Liriodendron chinense)have much larger macrofibrils than their hardwood relatives.Hardwood angiosperm macrofibrils are about 15 nanometres in diameter and faster growing softwood gymnosperm macrofibrils have larger 25 nanometre macrofibrils.Tulip Trees have macrofibrils somewhere in between,measuring 20 nanometres. 查看详细>>

DALLAS–July 31,2024–Researchers at UT Southwestern Medical Center have discovered that adiet free of the amino acid tryptophan can effectively halt the growth of liver cancer in mice.Their findings,published in Nature Communications,offer new insights for dietary-based cancer treatments and highlight the critical role of the tryptophan metabolite indole 3-pyruvate(I3P)in liver tumor development.“This work demonstrates that tailored dietary modulation may serve as apowerful adjuvant in cancer treatment,”said study leader Maralice Conacci-Sorrell,Ph.D.,Associate Professor of Cell Biology and Children’s Medical Center Research Institute at UT Southwestern(CRI)and amember of the Cellular Networks in Cancer Research Program of the Harold C.Simmons Comprehensive Cancer Center.“It builds on our lab’s discovery that the universal oncogene MYC increases the demand for tryptophan in liver tumors.”Hepatocellular carcinoma(HCC)is the third-leading cause of cancer-related mortality worldwide,according to 2020 data from the World Health Organization,with limited options for effective treatment and afive-year survival rate of about 30%.The study shows that growth of liver cancers driven by the MYC oncogene is particularly dependent on tryptophan,which is converted into I3P as well as other metabolites.By removing tryptophan from the diet of mice,researchers stopped the growth of MYC-driven liver tumors and restored normal gene expression in liver cells.Notably,this dietary intervention did not affect protein synthesis in normal cells,suggesting atargeted therapeutic approach that spares healthy tissues.“Liver tumors require large amounts of tryptophan to generate the oncometabolite I3P,”Dr.Conacci-Sorrell said.“A tryptophan-free diet prevents liver tumor growth by amechanism that depends on I3P but is independent of translation,the process by which proteins are synthesized from amino acid building blocks.Because tryptophan is the amino acid with the lowest abundance in the proteome,short-term dietary manipulation is safe for healthy tissues but not for cancer cells.” 查看详细>>

A‘human challenge’study–purposefully infecting volunteers with malaria–has revealed crucial insights into how new,more effective malaria vaccines can be designed.Malaria is transmitted by certain species of mosquitoes and was responsible for an estimated 608,000 deaths in 2022,largely in sub-Saharan Africa.The trial showed that the principle behind most vaccines–producing antibodies that attach to the pathogen and block it from entering human cells–is only part of the story for malaria infection.Instead,antibodies that effectively‘recruit’other parts of the immune system were shown to be more protective against the illness in malaria infection.The international research team have already isolated one potential route to producing these kinds of antibodies,and are manufacturing experimental vaccines on multiple platforms to identify which one induces the best response.The research,led by scientists from Imperial College London,Heidelberg University Hospital and the Kenya Medical Research Institute,is published in the journals Immunity and Life Science Alliance.Lead researcher Professor Faith Osier,Co-Director of the Institute of Infection and Chair in Malaria Immunology&Vaccinology in the Department of Life Sciences at Imperial College London,and Director of Chanjo Hub,said:“Malaria is still aserious burden that kills hundreds of thousands of people every year,mostly children under five years old.We have many tools to fight the disease,but progress has stalled,and we badly need malaria vaccines that are highly effective and offer long-term protection.“Our study shows that the way we have been thinking about vaccines is too narrow in terms of how they might work.These findings could improve vaccines for malaria and beyond,potentially saving many lives worldwide.” 查看详细>>

“Our findings support shared biological pathways underlying both heart failure and frailty,suggesting interventions to prevent or treat one outcome may help decrease the burden of the other,”said study leader Amil Shah,M.D.,M.P.H.,Professor of Internal Medicine in the Division of Cardiology and in the Peter O’Donnell Jr.School of Public Health at UT Southwestern.As the world’s population ages,so do the prevalence and incidence of heart failure and frailty,disorders that tend to occur in the seventh decade of life and beyond.Heart failure is characterized by an inability of the heart to keep up with the body’s demands;symptoms of frailty are ageneral loss of physical function,with features often including unintentional weight loss,physical exhaustion,and low physical activity.Frailty occurs in up to half of people with heart failure,and the risk of heart failure increases in people with frailty.Although inflammation has been implicated in both of these multisystem disorders,whether heart failure and frailty share molecular pathways has been unknown.To answer this question,Dr.Shah and colleagues across the country used data from the Atherosclerosis Risk in Communities(ARIC)study,an ongoing longitudinal study initiated in the late 1980s at sites in North Carolina,Mississippi,Minnesota,and Maryland.Originally meant to investigate factors that influence atherosclerosis risk in study participants over aseries of visits,ARIC has expanded its scope over the past four decades,including an assessment of frailty at study visits five,six,and seven between 2011 and 2019. 查看详细>>

Unlike traditional printed circuit boards,which are flat,3D circuitry enables components to be stacked and integrated vertically—dramatically reducing the footprint required for devices.Advancing the frontiers of 3D printed circuits,a team of researchers from the National University of Singapore(NUS)has developed astate-of-the-art technique-known as tension-driven CHARM3D-to fabricate three-dimensional(3D),self-healing electronic circuits.This new technique enables the 3D printing of free-standing metallic structures without requiring support materials and external pressure.The research team led by Associate Professor Benjamin Tee from the Department of Materials Science and Engineering in the NUS College of Design and Engineering used Field’s metal to demonstrate how CHARM3D can fabricate awide range of electronics,allowing for more compact designs in devices such as wearable sensors,wireless communication systems and electromagnetic metamaterials.In healthcare,for instance,CHARM3D facilitates the development of contactless vital sign monitoring devices—enhancing patient comfort while enabling continuous monitoring.In signal sensing,it optimises the performance of 3D antennas,leading to improved communication systems,more accurate medical imaging and robust security applications.The team’s findings were published in the journal Nature Electronics on 25 July 2024.Assoc Prof Tee is the corresponding author of the research paper. 查看详细>>

Researchers at the University of Toronto’s Faculty of Applied Science&Engineering have designed anovel way to recycle steel that could help decarbonize several manufacturing industries and usher in acircular steel economy.The new method introduces an innovative oxysulfide electrolyte for electrorefining,an alternative way of removing copper and carbon impurities from molten steel.The process also generates liquid iron and sulfur as by-products.It’s outlined in anew paper published in Resources,Conservation and Recycling and co-authored by Jaesuk(Jay)Paeng,a PhD candidate in the department of chemical engineering and applied chemistry,William Judge,a PhD alum from the department of materials science and engineering,and Professor Gisele Azimi from the department of chemical engineering and applied chemistry.“Our study is the first reported instance of electrochemically removing copper from steel and reducing impurities to below alloy level,”says Azimi,who holds the Canada Research Chair in Urban Mining Innovations.Currently,only 25 per cent of steel produced comes from recycled material.But the global demand for greener steel is projected to grow over the next two decades as governments around the world endeavour to achieve net-zero emission goals.Steel is created by reacting iron ore with coke–a prepared form of coal–as the source of carbon and blowing oxygen through the metal produced.Current processes generate nearly two tonnes of carbon dioxide per tonne of steel produced,making steel production one of the highest contributors to carbon emissions in the manufacturing sector.Traditional steel recycling methods use an electric arc furnace to melt down scrap metal.Since it is difficult to physically separate copper material from scrap before melting,the element is also present in the recycled steel products.“The main problem with secondary steel production is that the scrap being recycled may be contaminated with other elements,including copper,”says Azimi.“The concentration of copper adds up as you add more scrap metals to be recycled,and when it goes above 0.1 weight percentage in the final steel product,it will be detrimental to the properties of steel.”Copper cannot be removed from molten steel scrap using the traditional electric arc furnace steelmaking practice,so this limits the secondary steel market to producing lower-quality steel product,such as reinforcing bars used in the construction industry.“Our method can expand the secondary steel market into different industries,”says Paeng.“It has the potential to be used to create higher-grade products such as galvanized cold rolled coil used in the automotive sector,or steel sheets for deep drawing used in the transport sector.”To remove copper from iron to below 0.1 weight percentage,the team had to first design an electrochemical cell that could withstand temperatures up to 1,600 degrees Celsius.Inside the cell,electricity flows between the negative electrode(cathode)and positive electrode(anode)through anovel oxysulfide electrolyte designed from slag—a waste derived from steelmaking that often ends up in cement or landfills. 查看详细>>

CRI Associate Professor Prashant Mishra,M.D.,Ph.D.,Xun Wang,Ph.D.,and colleagues have found that hepatocytes,the cells responsible for most liver function,normally use their mitochondria to process fatty acids,a key energy source during regeneration.When their mitochondria are damaged,hepatocytes turn on PDK4–a metabolic enzyme that restricts cells from shifting to an alternative energy source–and cells die.“There are good and bad sides of metabolic flexibility.Although metabolic flexibility has been largely described as beneficial because it gives cells the ability to tolerate shifting environments or alternative nutritional sources,our findings suggest flexibility can also be detrimental by allowing damaged cells to survive,”Dr.Mishra said.“With mitochondrial damage,liver cells actively suppress flexibility–a good thing if it prevents the damage from spreading.”CRI scientists initially studied the mitochondria of healthy liver cells,both under normal and regenerative conditions.Their analyses showed fatty acids from other parts of the body were transported through the blood to the liver to fuel regeneration.When researchers blocked fatty acid transit,heathy livers were flexible and shifted to other energy sources,including sugars like glucose.Researchers then examined livers from mice with mutations in their mitochondrial genes.Damaged liver cells were unable to use fatty acids during regeneration and did not shift to other energy sources,preventing livers from regenerating.To understand why the flexibility was suppressed by mitochondrial mutations,Mishra Lab members examined genes that control acell’s ability to use alternate energy sources.Results showed increased levels of the PDK4 gene–a negative regulator of apathway needed to generate energy from glucose.When researchers blocked PDK4,damaged cells in the liver became metabolically flexible and were able to use other energy sources to spread and duplicate. 查看详细>>

n their latest study,Iwasaki’s team analyzed blood samples from patients in the Mount Sinai-Yale Long COVID study.This cohort of over 215 Long COVID patients is part of acollaboration between Iwasaki and David Putrino,PhD,professor in the Department of Rehabilitation and Human Performance at Icahn School of Medicine at Mount Sinai in New York City.As part of this joint effort,Putrino’s clinic obtained blood samples from patients enrolled in the study.Iwasaki’s laboratory then purified antibodies from the blood and transferred them into healthy mice.Next,the researchers led by Keyla Sá,a postdoctoral fellow in Iwasaki’s lab,conducted multiple behavioral experiments to look for Long COVID symptoms.While many of these experiments found no significant difference between the experimental and control mice,a few revealed striking changes in those that received antibodies.In one such experiment,researchers placed the mice on aheated plate and measured how long it took for them to react.Some mice that received antibodies reacted significantly more quickly to the heat,indicating aheightened sensitivity to pain.The researchers went back and identified the patients whose antibodies had been injected into the mice.Interestingly,these patients reported pain as one of their Long COVID symptoms.Another experiment was the rotarod test,in which researchers placed mice on arotating cylinder to measure coordination and balance.Mice that received antibodies were more likely to struggle to stay on the apparatus.Once again,when the researchers looked at the source of these antibodies,they learned that they were mostly from patients who reported suffering from dizziness.The mice also underwent agrip strength test,in which researchers measured the force applied by the animals to agrid apparatus.A group of mice were found to have reduced muscle strength if they received antibodies from patients reporting tinnitus and headache.Thus,antibodies capable of impairing muscle function are found in patients with these symptoms.How exactly these antibodies cause pathology needs more study. 查看详细>>

Two-dimensional(2D)materials have atomic-level thickness and excellent mechanical and physical properties,with broad application prospects in fields such as semiconductors,flexible devices,and composite materials.Due to their extremely low bending stiffness,single-layer 2D materials will undergo out-of-plane deformation when subjected to geometric constraints,forming ripples,buckling,wrinkling,or even creases,which can significantly affect their mechanical,electrical,and thermal properties.Their mechanical stability also directly affects the lifespan and service performance of devices based on suspended 2D materials,such as micro/nanoelectromechanical systems(M/NEMS),resonators/oscillators,nano kirigami/origami,proton transport membranes,and nanochannels.Clarifying the mechanical stability mechanisms of 2D materials and achieving overall control of their instability behaviours is crucial for the mechanical applications of 2D materials and other atomically thin films.A research team led by Professor Yang Lu from the Department of Mechanical Engineering at the University of Hong Kong(HKU)has made asignificant breakthrough in this area by providing anew method for assessing instability in atomically thin films.In collaboration with researchers from the University of Science and Technology of China,Professor Lu’s team proposed a“push-to-shear”strategy to achieve in situ observation of the in-plane shear deformation of single-layer 2D materials for the first time,achieving controllable tuning of the instability characteristics of 2D materials.Combining theoretical analysis and molecular dynamics simulations,the mechanical principles and control mechanisms of multi-order instability in atomically thin films were revealed.The results have been published in the academic journal Nature Communications with the paper titled“Tuning Instability in Suspended Monolayer 2D Materials”.The team is planning to collaborate with industrial partners to develop anew type of mechanical measurement platform for atomically thin films,which utilizes in-situ micro/nanomechanical techniques to achieve high-throughput mechanical property measurements while also enabling deep strain engineering of the materials’device physical properties.“This research breakthrough overcomes the difficulty of controlling the instability behaviour of suspended single-atom-layer 2D materials,achieving the measurement of the bending stiffness of single-layer graphene and molybdenum disulfide(MoS2).The study also provides new opportunities for modulating the nano-scale instability morphology and physical properties of atomically thin films,”said Professor Lu.“We developed aMEMS-based in-situ shearing device to control the instability behaviour of suspended single-layer 2D materials,which is also applicable to other atomically thin films.We further investigated the evolution of the wrinkle morphology of 2D materials induced by instability,uncovering different instability and recovery paths dominated by changes in the wavelength and amplitude of wrinkles,and providing anew experimental mechanics method for assessing the instability behaviour and bending performance of atomically thin films.In addition,the local stress/strain and curvature changes related to the instability process of 2D materials have important applications in physical and chemical fields,such as changing the electronic structure by adjusting the wrinkled morphology and establishing fast proton transport channels(see Figure 1).”Professor Lu added.“This research has achieved controllable instability modulation of atomically thin materials represented by 2D materials.Compared to traditional tensile strain engineering,shear strain can deeply regulate the band structure of 2D materials.In the future,we will continue to advance this research and ultimately hope to achieve an integrated design of mechanics and functionality in low-dimensional materials under deep strain,”said Dr Hou Yuan,the first author of the paper and apostdoctoral fellow in Professor Lu’s group. 查看详细>>

The concept of short-range order(SRO)—the arrangement of atoms over small distances—in metallic alloys has been underexplored in materials science and engineering.But the past decade has seen renewed interest in quantifying it,since decoding SRO is acrucial step toward developing tailored high-performing alloys,such as stronger or heat-resistant materials.Understanding how atoms arrange themselves is no easy task and must be verified using intensive lab experiments or computer simulations based on imperfect models.These hurdles have made it difficult to fully explore SRO in metallic alloys.But Killian Sheriff and Yifan Cao,graduate students in MIT’s Department of Materials Science and Engineering(DMSE),are using machine learning to quantify,atom-by-atom,the complex chemical arrangements that make up SRO.Under the supervision of Assistant Professor Rodrigo Freitas,and with the help of Assistant Professor Tess Smidt in the Department of Electrical Engineering and Computer Science,their work was recently published in The Proceedings of the National Academy of Sciences.Interest in understanding SRO is linked to the excitement around advanced materials called high-entropy alloys,whose complex compositions give them superior properties.Typically,materials scientists develop alloys by using one element as abase and adding small quantities of other elements to enhance specific properties.The addition of chromium to nickel,for example,makes the resulting metal more resistant to corrosion.Unlike most traditional alloys,high-entropy alloys have several elements,from three up to 20,in nearly equal proportions.This offers avast design space.“It’s like you’re making arecipe with alot more ingredients,”says Cao.The goal is to use SRO as a“knob”to tailor material properties by mixing chemical elements in high-entropy alloys in unique ways.This approach has potential applications in industries such as aerospace,biomedicine,and electronics,driving the need to explore permutations and combinations of elements,Cao says. 查看详细>>