A new catalyst made from an inexpensive,abundant metal and common table sugar has the power to destroy carbon dioxide(CO2)gas.In anew Northwestern University study,the catalyst successfully converted CO2 into carbon monoxide(CO),an important building block to produce avariety of useful chemicals.When the reaction occurs in the presence of hydrogen,for example,CO2 and hydrogen transform into synthesis gas(or syngas),a highly valuable precursor to producing fuels that can potentially replace gasoline.With recent advances in carbon capture technologies,post-combustion carbon capture is becoming aplausible option to help tackle the global climate change crisis.But how to handle the captured carbon remains an open-ended question.The new catalyst potentially could provide one solution for disposing the potent greenhouse gas by converting it into amore valuable product.The study will be published in the May 3issue of the journal Science.“Even if we stopped emitting CO2 now,our atmosphere would still have asurplus of CO2 as aresult of industrial activities from the past centuries,”said Northwestern’s Milad Khoshooei,who co-led the study.“There is no single solution to this problem.We need to reduce CO2 emissions and find new ways to decrease the CO2 concentration that is already in the atmosphere.We should take advantage of all possible solutions.”“We’re not the first research group to convert CO2 into another product,”said Northwestern’s Omar K.Farha,the study’s senior author.“However,for the process to be truly practical,it necessitates acatalyst that fulfills several crucial criteria:affordability,stability,ease of production and scalability.Balancing these four elements is key.Fortunately,our material excels in meeting these requirements.”An expert in carbon capture technologies,Farha is the Charles E.and Emma H.Morrison Professor of Chemistry at Northwestern’s Weinberg College of Arts and Sciences.After starting this work as aPh.D.candidate at the University of Calgary in Canada,Khoshooei now is apostdoctoral fellow in Farha’s laboratory. 查看详细>>

The study was published today(Sept.20)in The Astrophysical Journal.According to new high-resolution 3D simulations,spinning black holes twist up the surrounding space-time,ultimately ripping apart the violent whirlpool of gas(or accretion disk)that encircles and feeds them.This results in the disk tearing into inner and outer subdisks.Black holes first devour the inner ring.Then,debris from the outer subdisk spills inward to refill the gap left behind by the wholly consumed inner ring,and the eating process repeats.One cycle of the endlessly repeating eat-refill-eat process takes mere months—a shockingly fast timescale compared to the hundreds of years that researchers previously proposed.This new finding could help explain the dramatic behavior of some of the brightest objects in the night sky,including quasars,which abruptly flare up and then vanish without explanation.“Classical accretion disk theory predicts that the disk evolves slowly,”said Northwestern’s Nick Kaaz,who led the study.“But some quasars—which result from black holes eating gas from their accretion disks—appear to drastically change over time scales of months to years.This variation is so drastic.It looks like the inner part of the disk—where most of the light comes from—gets destroyed and then replenished.Classical accretion disk theory cannot explain this drastic variation.But the phenomena we see in our simulations potentially could explain this.The quick brightening and dimming are consistent with the inner regions of the disk being destroyed.”Kaaz is agraduate student in astronomy at Northwestern’s Weinberg College of Arts and Sciences and member of the Center for Interdisciplinary Exploration and Research in Astrophysics(CIERA).Kaaz is advised by paper co-author Alexander Tchekhovskoy,an associate professor of physics and astronomy at Weinberg and aCIERA member.Mistaken assumptions Accretion disks surrounding black holes are physically complicated objects,making them incredibly difficult to model.Conventional theory has struggled to explain why these disks shine so brightly and then abruptly dim—sometimes to the point of disappearing completely.Previous researchers have mistakenly assumed that accretion disks are relatively orderly.In these models,gas and particles swirl around the black hole—in the same plane as the black hole and in the same direction of the black hole’s spin.Then,over atime scale of hundreds to hundreds of thousands of years,gas particles gradually spiral into the black hole to feed it.“How gas gets to ablack hole to feed it is the central question in accretion-disk physics.If you know how that happens,it will tell you how long the disk lasts,how bright it is and what the light should look like when we observe it with telescopes.”—Nick Kaaz,lead author“For decades,people made avery big assumption that accretion disks were aligned with the black hole’s rotation,”Kaaz said.“But the gas that feeds these black holes doesn’t necessarily know which way the black hole is rotating,so why would they automatically be aligned?Changing the alignment drastically changes the picture.”The researchers’simulation,which is one of the highest-resolution simulations of accretion disks to date,indicates that the regions surrounding the black hole are much messier and more turbulent places than previously thought. 查看详细>>

Renowned researcher Jeffrey A.Hubbell has received the 2023 Kabiller Prize in Nanoscience and Nanomedicine,an annual award given by Northwestern University’s International Institute for Nanotechnology(IIN)to one scientist for outstanding achievements in the field.Hubbell’s work has revolutionized the fields of nanoscale bioengineering and regenerative medicine,exemplifying the spirit of innovation and excellence that the Kabiller Prize represents.He also has demonstrated acommitment to advancing scientific discovery for the betterment of humanity.“Receiving the Kabiller Prize in Nanoscience and Nanomedicine is atrue honor,”said Hubbell,the Eugene Bell Professor in Tissue Engineering at University of Chicago’s Pritzker School of Molecular Engineering.“I undertake research in nanomedicine from an engineering perspective,diving deeply into the biology with the hope and goal of improving lives.Together with my colleagues and students,I am confident we will continue to make advances.”Said Michael H.Schill,president of Northwestern University:“It is aprivilege to honor Jeffrey Hubbell as this year‘s Kabiller Prize winner within the auspices of IIN.His groundbreaking work and transformative achievements in the field of nano bioengineering resonate perfectly with IIN‘s mission to advance knowledge and pioneer breakthroughs that promise abetter future for humanity.”Jeffrey Hubbell,a nano bioengineering pioneer Hubbell’s contributions to tissue engineering and regenerative medicine have laid the foundation for innovative approaches that bridge the gap between laboratory discoveries and real-world clinical applications.His visionary work on inverse vaccines using polymeric nanovectors promises to revolutionize the field by offering new routes to the treatment of difficult-to-treat conditions like celiac disease and multiple sclerosis.Beyond the laboratory,his leadership and founding of Anokion,Inc.underscores his dedication to translating cutting-edge breakthroughs into practical medical solutions.Moreover,Hubbell‘s impact extends to immuno-oncology,where his matrix-binding technologies pave the way for next-generation biologics with the potential to reshape cancer treatment.His leadership in founding Arrow Immune,Inc.further exemplifies his commitment to translating innovative technologies into the clinic,promising abrighter future for cancer patients.“Jeffrey Hubbell’s legacy in the field of nanotechnology is marked by innovation and impact,”said David Kabiller,a business leader and philanthropist whose generous donation established the prize.“His groundbreaking work,from developing polymeric nanovectors for novel vaccines to engineering cytokines for autoimmune diseases,has demonstrated the power of nanotechnology in transforming health care.With this year‘s Kabiller Prize,we honor not only his achievements,but also his commitment to translating these technologies from the lab to the clinic,positively affecting countless lives.”Hubbell’s engineering of cytokines to modulate inflammatory responses,particularly in autoimmune diseases,showcases his dedication to address pressing medical challenges.His founding of HeioThera,Inc.further emphasizes his commitment to ensuring that these breakthroughs reach those in need.“Jeff Hubbell is apioneering researcher and early entrepreneur in tissue engineering who has made atremendous difference to the field,”said Matthew Tirrell,dean of the Pritzker School of Molecular Engineering at University of Chicago.“In addition to his distinguished achievements in bioengineering and immunotherapy,Jeff also has trained dozens of other leaders in the field in his laboratory.His innovative development of materials that stimulate the immune system to fight infection or malignancy according to design,disabling certain aspects of the immune response to address auto-immune diseases such as multiple sclerosis or celiac disease have affected people for the better.Jeff Hubbell’s extraordinary accomplishments truly merit the Kabiller Prize in Nanoscience and Nanomedicine.” 查看详细>>

An international team of researchers,including Northwestern University astrophysicists,have used agalaxy-sized tool composed of 68 dead stars to sense the longest,slowest gravitational waves ever detected.With lengths equivalent to 15 light-years,some of the waves are so long and slow that it takes 15 years for each individual wave cycle to fully pass through Earth.Together,these gravitational wave signals overlap,like voices in acrowd or instruments in an orchestra,producing an overall cosmic“hum”that imprints apattern in the data.The record-breaking gravitational-wave signal was observed in 15 years of data acquired by the North American Nanohertz Observatory for Gravitational Waves(NANOGrav)Physics Frontiers Center(PFC),a collaboration of nearly 200 scientists from the United States and Canada who use atype of exotic neutron star,called pulsars,to search for gravitational waves.While earlier results from NANOGrav uncovered an enigmatic timing signal common to all the pulsars they observed,the signal was too faint for researchers to determine its origin.The 15-year dataset release demonstrates that the signal is consistent with slowly undulating gravitational waves passing through our galaxy.By further investigating these monster waves,astrophysicists could potentially learn more about how the universe evolved on the largest scales,how often galaxies collide and what drives black holes to merge.A suite of four papers detailing the new discovery will be published on June 28 in The Astrophysical Journal Letters.Northwestern postdoctoral fellow Caitlin Witt co-authored all four papers as well as acomplementary set of papers now available on ArXiv.A public lecture will air on YouTube at 1p.m.EDT(U.S.)on Thursday,June 29.“We think the most likely source of this type of signal is apopulation of supermassive black hole binaries,but we want to be careful not to assume that,”Witt said.“Scientists also have theorized that it could be remnants from the Big Bang or cosmic strings generating this signal.The publication of these studies is not the end of our research but the beginning.It’s the starting gun,marking the beginning of trying to understand this new population of gravitational waves.”Witt is the inaugural CIERA-Adler Postdoctoral Fellow at Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics(CIERA)and the Adler Planetarium.Luke Kelley,an astrophysicist at the University of California,Berkeley and former postdoctoral fellow at CIERA,is chair of NANOGrav’s astrophysics group.The NANOGrav Collaboration is led by Stephen Taylor of Vanderbilt University,Maura McLaughlin of West Virginia University and Xavier Siemens of Oregon State University.Tracking squeezed space-time with cosmic timepieces In 2016,an international collaboration including Northwestern professor Vicky Kalogera,who was aleading astrophysicist on the team,used the Laser Interferometer Gravitational-Wave Observatory(LIGO)to first detect gravitational waves from the merger of two stellar-mass black holes,which resulted in obvious,short-lived ripples in space-time.But the newly discovered population of gravitational waves is too big and change much too slowly for Earth-based equipment like LIGO to detect.Even when NASA and the European Space Agency launch LISA(a space-based gravitational wave detector for which Northwestern professor Shane Larson is amember of the science collaboration)in the early 2030s,it still will not be able to detect such enormous waves.To overcome this obstacle,NANOGrav leverages pulsars,a type of rapidly rotating neutron star born in the supernova explosion of amassive star at the end of its life.Just like alighthouse,a pulsar spins rapidly,sweeping radio waves through space,so they appear to“pulse”when viewed from Earth.The fastest of these objects,called millisecond pulsars,spin hundreds of times per second. 查看详细>>

The Office of Undergraduate Research recognized six undergraduate students and two faculty members during the Fletcher Awards ceremony on Dec.2 in Evanston.The$250 prize,funded by the Fletcher Family Foundation,honors outstanding undergraduates for research conducted with support from aSummer Undergraduate Research Grant(SURG).Since last year,the Fletcher Awards also recognize rising research stars and excellence in research mentorship through the Undergraduate Research Assistant Program(URAP).SURGs award students$4,000 to do an independent academic or creative project,in all fields of study,under faculty supervision.URAP pays student research assistants to work with afaculty mentor on their research project to provide research-related skills.“Undergraduate research challenges students to think and collaborate in new ways,to add meaningful knowledge to the world,and to raise the bar of their own expectation,”said Peter Civetta,director of the Office of Undergraduate Research.“While we know research is impactful,we also know that students do not necessarily know how to engage in—or even approach—research.These programs,and specifically these faculty mentors,provide transformative opportunities and,when given these opportunities,the Fletcher Award winners show what is possible.”Summer Undergraduate Research Grant winners John Chen’24 of McCormick is mentored by Erica Hartmann on aproject exploring differences in the functional connectivity of brain networks between normally-aging and Parkinson‘s disease subjects.Studying temporal and budget dynamics in education crowdfunding,Elizabeth Dudley’24 of Weinberg is mentored by Elizabeth Gerber.Elena Housteau’24 of Weinberg is exploring differences in the connectivity of brain networks in normally-aging and Parkinson’s disease subjects in aproject guided by Caterina Gratton.Mentored by David Tolchinsky,Danielle Llevada’23 of the School of Communication is developing anew television comedy series that depicts depression and mental health.Undergraduate Research Assistant Program winners Sophia Huang’25 of Weinberg,mentored by by Gregory Phillips II,is working on aproject titled“Intersectional Approaches to Population-Level Health Research:Role of HIV Risk and Mental Health in Alcohol Use Disparities among Diverse Sexual Minority Youth.”Kadin Mills’24 of Medill is mentored by Patty Low on amedia project that will invite public audiences to explore their connections to the changing climate and their identities as changemakers.Undergraduate Research Assistant Program faculty award winners Sara Moreira of the Kellogg School of Management is mentoring Kushal Mungee on aproject titled“The Anatomy of Financial Innovation.”Jason Roberts of the Office of Fellowships and the School of Communication is mentoring Petra Popper Freedman on“Too Big to Screen:Moving-Image Media and the Great Recession.” 查看详细>>

Northwestern Medicine scientists have uncovered the mechanism behind why eating late at night is linked to weight gain and diabetes.The connection between eating time,sleep and obesity is well-known but poorly understood,with research showing that overnutrition can disrupt circadian rhythms and change fat tissue.New Northwestern research has shown for the first time that energy release may be the molecular mechanism through which our internal clocks control energy balance.From this understanding,the scientists also found that daytime is the ideal time in the light environment of the Earth’s rotation when it is most optimal to dissipate energy as heat.These findings have broad implications from dieting to sleep loss and the way we feed patients who require long-term nutritional assistance.The paper,“Time-restricted feeding mitigates obesity through adipocyte thermogenesis,”will be published online today,and in print tomorrow(Oct.21)in the journal Science."It is well known,albeit poorly understood,that insults to the body clock are going to be insults to metabolism,”said corresponding study author Dr.Joseph T.Bass,the Charles F.Kettering Professor of Medicine at Northwestern University Feinberg School of Medicine.He also is aNorthwestern Medicine endocrinologist.“When animals consume Western style cafeteria diets—high fat,high carb—the clock gets scrambled,”Bass said.“The clock is sensitive to the time people eat,especially in fat tissue,and that sensitivity is thrown off by high-fat diets.We still don’t understand why that is,but what we do know is that as animals become obese,they start to eat more when they should be asleep.This research shows why that matters.”Bass is also director of the Center for Diabetes and Metabolism and the chief of endocrinology in the department of medicine at Feinberg.Chelsea Hepler,a postdoctoral fellow in the Bass Lab,was the first author and did many of the biochemistry and genetics experiments that grounded the team’s hypothesis.Rana Gupta,now at Duke University,was also akey collaborator.Scrambling the internal clock In the study,mice,who are nocturnal,were fed ahigh-fat diet either exclusively during their inactive(light)period or during their active(dark)period.Within aweek,mice fed during light hours gained more weight compared to those fed in the dark.The team also set the temperature to 30 degrees,where mice expend the least energy,to mitigate the effects of temperature on their findings.“We thought maybe there’s acomponent of energy balance where mice are expending more energy eating at specific times,”Hepler said.“That’s why they can eat the same amount of food at different times of the day and be healthier when they eat during active periods versus when they should be sleeping.”The increase in energy expenditure led the team to look into metabolism of fat tissue to see if the same effect occurred within the endocrine organ.They found that it did,and mice with genetically enhanced thermogenesis—or heat release through fat cells—prevented weight gain and improved health.Hepler also identified futile creatine cycling,in which creatine(a molecule that helps maintain energy)undergoes storage and release of chemical energy,within fat tissues,implying creatine may be the mechanism underlying heat release.Findings could inform chronic care The science is underpinned by research done by Bass and colleagues at Northwestern more than 20 years ago that found arelationship between the internal molecular clock and body weight,obesity and metabolism in animals.The challenge for Bass’s lab,which focuses on using genetic approaches to study physiology,has been figuring out what it all means,and finding the control mechanisms that produce the relationship.This study brings them astep closer.The findings could inform chronic care,Bass said,especially in cases where patients have gastric feeding tubes.Patients are commonly fed at night while they sleep,when they’re releasing the least amount of energy.Rates of diabetes and obesity tend to be high for these patients,and Bass thinks this could explain why.He also wonders how the research could impact Type II Diabetes treatment.Should meal times be considered when insulin is given,for example?Hepler will continue to research creatine metabolism.“We need to figure out how,mechanistically,the circadian clock controls creatine metabolism so that we can figure out how to boost it,”she said.“Clocks are doing alot to metabolic health at the level of fat tissue,and we don’t know how much yet.” 查看详细>>

Matthew Coile has been passionate about science for as long as he can remember.“Science is fascinating,”he said,“and there’s always another new and exciting challenge to take on.”A Northwestern graduate student in chemical engineering,Coile is focused on designing highly recyclable plastics.He works in the lab of Linda Broadbelt,the Sarah Rebecca Roland Professor and associate dean for research at the McCormick School of Engineering.“Every time Ihave adiscussion with Linda,she says something insightful and impactful,”Coile said.He utilizes computational tools to design highly recyclable polyurethanes,the sixth-most produced class of plastics globally.While the top five plastics are easily recyclable,most polyurethanes are thermosets,composed of permanent crosslinked polymer structures that prevent them from being melted and remolded.As aresult,much of the material is unrecyclable and ends up in landfills.A new avenue of scientific research,however,aims to create polymer networks that can undergo triggerable,reversible reactions and be reconfigured,allowing the material to re-equilibrate to anew state.Coile uses computational models to determine the optimal conditions and monomer combinations to design such“covalent adaptable networks”or,in other words,recyclable thermosets.The ability to reuse polyurethanes would have significant environmental and economic benefits,with real-world applications from recyclable shoe soles to mattresses.In 2019,he received the Ryan Fellowship for students dedicated to the exploration of fundamental nanoscale science.The Patrick G.and Shirley W.Ryan Family Fellowship in Nanotechnology prepares top graduate students like Coile to assume leadership roles in academia and industry.The fellowship program was established in 2007 through agenerous gift from the Patrick G.’59,’09 Hand Shirley W.Ryan’61,’19 H(’97,’00 P)Family.Over the last 15 years,212 fellows have been funded from 10 different departments across multiple disciplines.More than 90 percent of former Ryan Fellows are now working in industry or academia.The remaining fellows have careers with governmental agencies,national laboratories,hospitals,or nonprofit organizations.Coile,originally from Gaithersburg,Maryland,has enjoyed networking opportunities through the Ryan Fellowship,connecting with other scientists and even taking on aproject with the Chicago-based Archer-Daniels-Midland Company before his Ph.D.program started.“It’s given me valuable experiences and connections that have helped in my Ph.D.research and beyond,”he said.In addition to the Ryan Fellowship,he earned aNational Science Foundation Graduate Research Fellowship.Beyond his current research ambitions,Coile said he hopes to one day lead agroup of his own at anational lab focused on chemical engineering challenges. 查看详细>>

The world knows SARS-CoV-2 intimately now,but there are more than 200 virus species capable of infecting humans and causing disease.And they all want to do the same thing:invade the host cells,hijack each cell’s machinery and reproduce.The human immune response system has numerous levels of robust defense,but many invading pathogens—as we are seeing now with the omicron variant—have away to break through.In anew study of the Zika virus,Northwestern University scientists have discovered akey mechanism used by the virus to evade the antiviral response of the cell it is attacking.This finding contributes to abetter understanding of how viruses infect cells,overcome immune barriers and replicate—information that is essential for fighting them.Zika virus is responsible for one of the most recent viral disease outbreaks prior to SARS-CoV-2,andthere are no vaccines or drugs for Zika disease.The Northwestern research reveals how the virus suppresses interferon signaling—a key player in initiating the antiviral immune response—to gain access to the cells.Identification of this specific virus-hos tinteraction offers anew target for antiviral therapeutics. 查看详细>>

Galaxies’spiral arms are responsible for scooping up gas to feed to their central supermassive black holes,according to anew high-powered simulation.Started at Northwestern University,the simulation is the first to show,in great detail,how gas flows across the universe all the way down to the center of asupermassive black hole.While other simulations have modeled black hole growth,this is the first single computer simulation powerful enough to comprehensively account for the numerous forces and factors that play into the evolution of supermassive black holes.The simulation also gives rare insight into the mysterious nature of quasars,which are incredibly luminous,fast-growing black holes.Some of the brightest objects in the universe,quasars often even outshine entire galaxies.“The light we observe from distant quasars is powered as gas falls into supermassive black holes and gets heated up in the process,”said Northwestern’s Claude-AndréFaucher-Giguère,one of the study’s senior authors.“Our simulations show that galaxy structures,such as spiral arms,use gravitational forces to‘put the brakes on’gas that would otherwise orbit galaxy centers forever.This breaking mechanism enables the gas to instead fall into black holes and the gravitational brakes,or torques,are strong enough to explain the quasars that we observe.”The research was published today(Aug.17)in the Astrophysical Journal.Faucher-Giguère is an associate professor of physics and astronomy at Northwestern’s Weinberg College of Arts and Sciences and amember of the Center for Interdisciplinary Exploration and Research in Astrophysics(CIERA).Daniel Anglés-Alcázar,an assistant professor at the University of Connecticut and former CIERA fellow in Faucher-Giguère’s group,is the paper’s first author.(Read UConn‘s interview with Daniel Anglés-Alcázar.)Equivalent to the mass of millions or even billions of suns,supermassive black holes can swallow 10 times the mass of asun in just one year.But while some supermassive black holes enjoy acontinuous supply of food,others go dormant for millions of years,only to reawaken abruptly with aserendipitous influx of gas.The details about how gas flows across the universe to feed supermassive black holes have remained along-standing question. 查看详细>>

Scientists have been searching for ways to develop materials that are as dynamic as living things,with the ability to change shape,move and change properties reversibly.Now,with nature as their inspiration,Northwestern University scientists have developed soft materials that autonomously self-assemble into molecular superstructures and remarkably disassemble on demand,changing the properties of materials and opening the door for novel materials in applications ranging from sensors and robotics to new drug delivery systems and tools for tissue regeneration.The highly dynamic new materials form hydrogels and also have provided unexpected biological clues about the brain micro-environment after injury or disease when their superstructures revealed reversible phenotypes in brain cells characteristic of injured or healthy brain tissue.“We are used to thinking of materials as having astatic set of properties,”said Samuel I.Stupp,co-corresponding author of the paper.“We’ve demonstrated that we can create highly dynamic synthetic materials that can transform themselves by forming superstructures and can do so reversibly on demand,which is areal breakthrough with profound implications.”The results are reported today(Oct.4)in the journal Science.Stupp is director of Northwestern’s Simpson Querrey Institute and is the Board of Trustees Professor of Materials Science and Engineering,Chemistry,Medicine and Biomedical Engineering.Erik Luijten,Professor and Chair of Materials Science and Engineering and Engineering Sciences and Applied Mathematics,is co-corresponding author.To create the material,Stupp and his postdoctoral fellow Ronit Freeman,now an associate professor at the University of North Carolina,Chapel Hill,developed some molecules composed of peptides(compounds of amino acids)and others composed of peptides and DNA.When placed together,these two types of molecules co-assembled to form water-soluble nanoscale filaments.When filaments containing complementary DNA sequences that could form double helices were mixed,the DNA-containing molecules designed to create double helices“jumped out”of their filaments to organize the unique complex superstructures,leaving behind the molecules without DNA to form simple filaments.The DNA superstructures,containing millions of molecules,looked like twisted bundles of filaments that reached dimensions on the order of microns in both length and width.The resulting material was initially asoft hydrogel,which became mechanically stiffer as the superstructures formed.The structures were hierarchical—meaning they contained ordered structures at different size scales.Nature does this very well—bone,muscle and wood are hierarchical materials—but such structures have been very difficult to achieve in synthetic materials.Even better,the researchers found that when they added asimple DNA molecule that could disrupt the double helices interconnecting filaments in the superstructures,the bundles came undone,and the material returned to its simple initial structure and softer state.Another type of molecule could then be used to reform the stiffer materials containing superstructures.That sort of reversibility had never before been achieved.To better understand how this process worked,Stupp connected with Luijten,a computational materials scientist.Luijten,with his graduate student Ming Han,developed simulations that helped explain the mechanics behind how and why the bundles formed and twisted.In such simulations,Han and Luijten could examine how each part of the designed molecules could govern the creation of the superstructures.After extensive computation—each calculation took weeks on Northwestern’s Quest supercomputer—they found that the molecules did not need DNA to bundle together but could be formed in principle by many other pairs of molecules with chemical structures that interact strongly with each other. 查看详细>>