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Yeom B.,University of Michigan | Yeom B.,Myongji University | Sain T.,Michigan Technological University | Lacevic N.,Urbana University | And 8 more authors.
Nature | Year: 2017

Tooth enamel comprises parallel microscale and nanoscale ceramic columns or prisms interlaced with a soft protein matrix. This structural motif is unusually consistent across all species from all geological eras. Such invariability - especially when juxtaposed with the diversity of other tissues - suggests the existence of a functional basis. Here we performed ex vivo replication of enamel-inspired columnar nanocomposites by sequential growth of zinc oxide nanowire carpets followed by layer-by-layer deposition of a polymeric matrix around these. We show that the mechanical properties of these nanocomposites, including hardness, are comparable to those of enamel despite the nanocomposites having a smaller hard-phase content. Our abiotic enamels have viscoelastic figures of merit (VFOM) and weight-adjusted VFOM that are similar to, or higher than, those of natural tooth enamels - we achieve values that exceed the traditional materials limits of 0.6 and 0.8, respectively. VFOM values describe resistance to vibrational damage, and our columnar composites demonstrate that light-weight materials of unusually high resistance to structural damage from shocks, environmental vibrations and oscillatory stress can be made using biomimetic design. The previously inaccessible combinations of high stiffness, damping and light weight that we achieve in these layer-by-layer composites are attributed to efficient energy dissipation in the interfacial portion of the organic phase. The in vivo contribution of this interfacial portion to macroscale deformations along the tooth's normal is maximized when the architecture is columnar, suggesting an evolutionary advantage of the columnar motif in the enamel of living species. We expect our findings to apply to all columnar composites and to lead to the development of high-performance load-bearing materials. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.


Yang M.,University of Michigan | Yang M.,Harbin Institute of Technology | Chan H.,University of Illinois at Chicago | Zhao G.,University of Pittsburgh | And 5 more authors.
Nature Chemistry | Year: 2017

Nanoscale compartments are one of the foundational elements of living systems. Capsids, carboxysomes, exosomes, vacuoles and other nanoshells easily self-assemble from biomolecules such as lipids or proteins, but not from inorganic nanomaterials because of difficulties with the replication of spherical tiling. Here we show that stabilizer-free polydispersed inorganic nanoparticles (NPs) can spontaneously organize into porous nanoshells. The association of water-soluble CdS NPs into self-limited spherical capsules is the result of scale-modified electrostatic, dispersion and other colloidal forces. They cannot be accurately described by the Derjaguin-Landau-Vervey-Overbeek theory, whereas molecular-dynamics simulations with combined atomistic and coarse-grained description of NPs reveal the emergence of nanoshells and some of their stabilization mechanisms. Morphology of the simulated assemblies formed under different conditions matched nearly perfectly the transmission electron microscopy tomography data. This study bridges the gap between biological and inorganic self-assembling nanosystems and conceptualizes a new pathway to spontaneous compartmentalization for a wide range of inorganic NPs including those existing on prebiotic Earth. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.


News Article | May 19, 2017
Site: www.eurekalert.org

After a 2015 national report detailed fragmentation among emergency medical services systems, Michigan Medicine researchers worked with stakeholders in Michigan to explore best practices in improving pre-hospital care ANN ARBOR, Mich. Emergency medical services are often the first to provide acute care to critically ill patients. These services can include private, government or publicly owned paramedic and ambulance services, as well as fire departments with EMS personnel. But delivery of that care isn't always seamless. Nor are the quality levels universal. The divide was the basis of a 2015 Institute of Medicine report that highlighted fragmentation among EMS systems in the United States and a lack of accountability and coordination at the state and federal levels. The findings compelled Mahshid Abir, M.D., assistant professor of emergency medicine at Michigan Medicine and director of the University of Michigan Acute Care Research Unit, to evaluate the quality of EMS oversight in Michigan and explore how EMS systems could work together to improve patient care. "This report identifies best practices in EMS oversight and informs related state policy in order to improve pre-hospital care quality," says Abir, who presented her findings at the 2017 Society for Academic Emergency Medicine annual meeting in Orlando, Florida. In its own evaluation, the Institute of Medicine (now the National Academy of Medicine) continually cited knowledge gaps in best practices in quality measurement and data reporting for EMS oversight. It also provided recommendations to better understand what roles the federal government, state governments and local communities have in oversight and evaluation of EMS systems. Abir and colleague Rekar Taymour, a research associate for the U-M Acute Care Research Unit, agreed with the recommendations. They sought to examine how those knowledge gaps could be filled regarding Michigan's 61 medical control authorities - through funding from the Michigan Department of Health and Human Services. Michigan HHS administered previous evaluation tools and held outcomes data within the Michigan EMS Information System (MI-EMSIS), a statewide repository of EMS data that contributes to a larger national repository. The authors' efforts were guided by their long-standing objective. "The U-M Acute Care Research Unit works to unify the delivery of acute care along its continuum, meaning pre-hospital care, emergency care, inpatient care and ambulatory care all play a role," says Abir, also a member of the Michigan Center for Integrative Research in Critical Care and the U-M Institute for Healthcare Policy and Innovation. The study involved three phases. In the first, researchers analyzed peer-reviewed and lay literature to evaluate the landscape and quality measures of EMS oversight. Phase two included a quantitative analysis of the MI-EMSIS to evaluate the degree to which reported data were missing. "MI-EMSIS is meant as a quality-assessment tool for pre-hospital care," Abir says. "However, it can only be used for this purpose if the reported data is complete and valid." Data evaluated included patient demographics, medication allergies, EMS provider impression and vital signs, among other variables. Finally, they performed focus groups and interviews with EMS stakeholders from diverse community settings, geographic regions and professional roles to understand factors associated with successful EMS oversight. The takeaway: Most quality measurement occurs at the EMS personnel level instead of the oversight and system levels, confirming the knowledge gap identified by the Institute of Medicine report. Findings from Abir's study shed light on key factors to developing quality measures for EMS oversight. The team found that the data being reported in MI-EMSIS were not always of high quality, and missing variables often differed based on software platform, EMS agency and the overseeing medical control authority. Stakeholders, the researchers note, attributed the missing data partly to data-mapping issues, uncertainty in how each authority defined some of the variables and unfamiliarity with reporting procedures. "We took the data from the three phases of the study and triangulated it," Abir says. "We found that high-quality EMS oversight occurs through seven key factors." "We noted that medical control authorities have to be deliberate and have structures and processes in place in each of these seven areas," Abir says. "If they do, we think it could greatly improve the quality and coordination of care EMS systems provide to patients." Based on the study findings, the team provided 20 recommendations to Michigan HHS to inform policy related to EMS oversight in the state. Among them: promoting EMS protocol consistency across the state; encouraging medical control authority boards to include representation from all key stakeholders; developing and disseminating a medical control authority guidebook of best practices to EMS agencies; exploring methods of providing consistent funding to medical control authorities through hospitals, EMS agencies, foundations and private industry; and promoting regional medical control authority conferences for leaders to coordinate and collaborate. "Unifying care across the acute care continuum -- including from the pre-hospital to emergency department and hospital settings -- through improved communication and collaboration is likely to lead to improved care quality and patient outcomes," Abir says. Through informing state policy regarding EMS oversight, Abir hopes the study and recommendations can help improve pre-hospital care quality and unify EMS services and other key stakeholders, and perhaps become an example for other states of how these services can work together more effectively through high-quality EMS oversight. "Medical control authorities can serve as a common point where stakeholders across the state, including hospitals, EMS agencies and police and fire departments can come together and improve pre-hospital care and patient outcomes," Abir says. "Collaboration is key."


Hsu Y.-Y.,University of Colorado at Boulder | Bortz D.M.,University of Colorado at Boulder | Younger J.G.,Michigan Center for Integrative Research in Critical Care | Younger J.G.,University of Michigan
Journal of Innate Immunity | Year: 2013

Opsonization and anaphylatoxin production are early events in the innate response to bacterial pathogens. Opsonization alone is frequently not lethal and production of anaphy-latoxins, especially C5a, allows for recruitment of cellular defenses. Complement biochemistry is extensively studied and computational models have been reported previously. However, a critical feature of complement-mediated attack is its spatial dependence: diffusion of mediators into and away from a bacterium is central to understanding C5a generation. Spatial dependence is especially important in biofilms, where diffusion limitation is crucial to bacterial counterdefense. Here we develop a model of opsonization and C5a production in the presence of a common blood-borne pathogen, Staphylococcus epidermidis. Our results indicate that when complement attacks a single cell, diffusion into the extracellular polymeric substance (EPS) is complete within 10 ms and that production of C5a peaks over the next 15 min. When longer diffusion lengths (as in an EPS-rich biofilm) are incorporated, diffusion limitation appears such that the intensity and duration of C5a production is increased. However, the amount of C5a produced under several likely clinical scenarios where single cells or sparse biofilms are present is below the kD of the C5a receptor suggesting that complement activation by a single bacterium may be difficult to detect when diffusion is taken into account. Copyright © 2013 S. Karger AG, Basel.


Wang X.,Harbin Institute of Technology | Lyu J.,Northwestern Polytechnical University | Kotov N.A.,University of Michigan | Kotov N.A.,Michigan Center for Integrative Research in Critical Care
ACS Nano | Year: 2016

Beam steering devices represent an essential part of an advanced optics toolbox and are needed in a spectrum of technologies ranging from astronomy and agriculture to biosensing and networked vehicles. Diffraction gratings with strain-tunable periodicity simplify beam steering and can serve as a foundation for light/laser radar (LIDAR/LADAR) components of robotic systems. However, the mechanical properties of traditional materials severely limit the beam steering angle and cycle life. The large strain applied to gratings can severely impair the device performance both in respect of longevity and diffraction pattern fidelity. Here, we show that this problem can be resolved using micromanufactured kirigami patterns from thin film nanocomposites based on high-performance stiff plastics, metals, and carbon nanotubes, etc. The kirigami pattern of microscale slits reduces the stochastic concentration of strain in stiff nanocomposites including those made by layer-by-layer assembly (LBL). The slit patterning affords reduction of strain by 2 orders of magnitude for stretching deformation and consequently enables reconfigurable optical gratings with over a 100% range of period tunability. Elasticity of the stiff nanocomposites and plastics makes possible cyclic reconfigurability of the grating with variable time constant that can also be referred to as 4D kirigami. High-contrast, sophisticated diffraction patterns with as high as fifth diffraction order can be obtained. The angular range of beam steering can be as large as 6.5° for a 635 nm laser beam compared to ∼1° in surface-grooved elastomer gratings and ∼0.02° in MEMS gratings. The versatility of the kirigami patterns, the diversity of the available nanocomposite materials, and their advantageous mechanical properties of the foundational materials open the path for engineering of reconfigurable optical elements in LIDARs essential for autonomous vehicles and other optical devices with spectral range determined by the kirigami periodicity. © 2016 American Chemical Society.


News Article | February 24, 2017
Site: www.eurekalert.org

ANN ARBOR, Mich. - They traveled a huge distance, evaded a protective barrier, and found themselves in a strange and unwelcoming land. They're looked at suspiciously for possible links to dangerous diseases, and are under constant threat of being expelled from their adopted home. Their contribution to the greater community is only beginning to be understood. And every day, more of them arrive. "They" are bacteria living in human lungs. And new research pinpoints just how they get there, and opens the door to more research on what happens to them - and our bodies - as a result. Writing in the journal mBio, researchers from the University of Michigan Medical School and VA Ann Arbor Healthcare System offer microbiome-based evidence that most of the bacteria in the lungs of healthy people got there by way of "microaspiration." In other words, they rode in on tiny droplets of saliva that made it from the microbe-filled mouth to the lungs. That means they avoided the movable tissue barrier called the epiglottis that keeps most saliva from getting into the lower respiratory tract. By studying the DNA of these bacteria throughout the lungs of healthy volunteers, the researchers confirmed that the population of microbes in the lungs closely resembles the population found in the mouth. And by studying their distribution within the airways, the researchers could determine their most likely route of entry. They found that many of the immigrant microbes make their home near the main carina, the spot at the end of the trachea where the airway branches off to the left and right lungs. This spot in the lungs is a "landing pad" where aspirated saliva - because of gravity and our upright posture - is likely to collide with the airway. But some bacteria manage to make it all the way to the deepest reaches of the pulmonary system, and reside in the tiny air sacs called alveoli. Wherever the bacteria land, the researchers found, they join a community made up of mostly other recent arrivals. Few microbes are thought to be long-term residents of healthy lungs. Unlike the gut, healthy lungs are an inhospitable environment for bacteria, with little nutrition, and constant surveillance by the lung's immune system. "This is the most comprehensive topographic survey of the healthy lung microbiome to date. It adds to the evidence that healthy lungs are like an island whose population is determined by the balance of immigration and elimination of species: who moves in and who moves out," says Robert P. Dickson, M.D., the first author of the new study. "The microbiome of the lung plays by a different ecologic rulebook than the gut microbiome, and this study helps clarify what those rules are." He and his colleagues, inspired by classic models of ecology, have proposed an "adapted island model" of the lung microbiome, in which the lung's ecosystem is determined by the competing pressures of microbial immigration and elimination. The new paper doesn't just describe the lung microbiome ecosystem - it also shows that scientists who want to study it in the future can feel confident using standard techniques that doctors already use to look for signs of lung disease. Dickson and his colleagues did their study in eight healthy volunteers who underwent bronchoscopy at VAAHS - allowing the researchers to pass a scope down their throat and into their lungs while they were under conscious sedation. The team got samples of lung bacteria using two different techniques to sample nine separate sites in the lungs of each volunteer. One technique, called protected specimen brushing, used a special catheter that keeps bacteria from the mouth and throat from contaminating the samples taken in the airways. Suspicion of such contamination has kept some researchers from fully accepting the results of previous lung microbiome research. So, to test for this contamination, the researchers took one sample on a brush held in the middle of the airway, and the rest using brushes that they gently touched to the airway wall. The researchers got other samples through bronchoalveolar lavage, in which they squirt a small amount of fluid into the deepest part of the lung and then suction it back into the bronchoscope, bringing microbes along with it. They then analyzed the bacterial DNA that they found in all these samples. "We found no evidence of upper respiratory tract bacteria in these contamination control specimens," says Dickson. "This reassured us that the rest of our samples truly reflected lung bacteria, and not just contamination from the procedure," brought in by the bronchoscope as it passed through the throat Taken together, the results suggest bronchoscope-based techniques can be used to study the lung microbiome -- in sickness and in health. "The lungs are our largest interface with the outside environment, with 70 square meters of surface area," says Dickson. "That's 30 times the size of the skin, and twice the size of the gastrointestinal tract. And this study confirms that they're under constant bombardment by diverse communities of bacteria." The researchers emphasize that these volunteers were healthy, and had no symptoms that suggested pneumonia or other respiratory disease. "These volunteers were as healthy as you or me," Dickson says. "We are probably all aspirating small amounts of bacteria constantly, and so long as our immune system is intact they rarely make us sick." Dickson notes that microaspiration in healthy people has been observed for nearly a century in studies using medical imaging techniques. "We've known about the existence of microaspiration for decades," says Dickson. "But this is the first time we've been able to find its ecologic fingerprint." Now that they understand more about the immigration question, Dickson and his colleagues aim to focus future research on what happens in people who have problems with the elimination part of the "adapted island" equation. Inability to cough irritants out of the lung, or carry them out through the sweeping action of hair-like cilia on lung cell surfaces, could lead to more microbes staying longer in the lungs than normal. And that could lead to a higher risk of lung infection. Such research could lead to better understanding of the lung microbiome's importance in conditions such as chronic obstructive pulmonary disorder, cystic fibrosis or the types of lung failure seen in intensive care units like the one where Dickson works at Michigan Medicine, the U-M academic medical center. "If healthy lungs are like Antarctica - where conditions aren't good for reproduction - then diseased lungs are more like a tropical island, where lower rates of elimination and altered environmental conditions permit the persistence and reproduction of certain bacteria," he says. As the father of two young children, he also thinks it would be interesting to study how the lung microbiome changes when a person has a viral infection that causes the upper respiratory tract to produce much more nasal secretions. "I certainly look at my kids with their constantly runny noses and wonder if their lung microbiome look more 'nasal' than 'oral.'" And, as researchers begin to uncover the impact of common medications such as antibiotics and proton pump inhibitors on the microbiome in the digestive system, he notes that it's not unreasonable to think that these drugs also affect the lung microbiome. He and colleagues have already found evidence that the lungs are filled with gut microbes in critically ill patients. In addition to Dickson, the new study's authors are John R. Erb-Downward, Christine M. Freeman, Lisa McCloskey, Nicole R. Falkowski, Gary B. Huffnagle, and Jeffrey L. Curtis. Huffnagle holds a joint appointment in the Department of Microbiology & Immunology. The research was sponsored by the National Institutes of Health (TR000433, HL130641, HL098961, HL114447) and the Department of Veterans Affairs, as well as the Michigan Institute for Clinical & Health Research, the U-M Medical School's Host Microbiome Initiative, and the Michigan Center for Integrative Research in Critical Care.


News Article | February 27, 2017
Site: www.futurity.org

Tiny droplets of saliva can carry bacteria from the mouth to the lungs, a new study shows. That means bacteria are able to avoid the epiglottis, the movable tissue barrier that keeps most saliva from getting into the lower respiratory tract. By studying the DNA of these bacteria in the lungs of healthy volunteers, researchers confirmed that the population of microbes in the lungs closely resembles the population found in the mouth. And by studying the microbes’ distribution within the airways, the researchers could determine their most likely entry route. They found that many of the immigrant microbes make their home near the main carina, the spot at the end of the trachea where the airway branches off to the left and right lungs. This spot in the lungs is a “landing pad” where aspirated saliva—because of gravity and our upright posture—is likely to collide with the airway. But some bacteria manage to make it all the way to the deepest reaches of the pulmonary system and reside in the tiny air sacs called alveoli. Wherever the bacteria land, they join a community made up mostly of other recent immigrants. Few microbes are thought to be long-term residents of healthy lungs. Unlike the gut, healthy lungs are an inhospitable environment for bacteria, with little nutrition and constant surveillance by the immune system. “This is the most comprehensive topographic survey of the healthy lung microbiome to date. It adds to the evidence that healthy lungs are like an island whose population is determined by the balance of immigration and elimination of species: who moves in and who moves out,” says Robert P. Dickson, assistant professor of internal medicine at the University of Michigan. “The microbiome of the lung plays by a different ecologic rulebook than the gut microbiome, and this study helps clarify what those rules are.” Inspired by classic models of ecology, researchers propose an “adapted island model” of the lung microbiome, in which the competing pressures of microbial immigration and elimination determine the lung’s ecosystem. The new paper, published in the journal mBio, doesn’t just describe the lung microbiome ecosystem; it also shows that scientists who want to study it in the future can feel confident using the standard techniques doctors already use to look for lung disease. Researchers conducted the study with eight healthy volunteers who underwent bronchoscopy at VA Ann Arbor Healthcare System. The team obtained the lung bacteria using two techniques to sample nine separate sites in the lungs of each volunteer. One technique, called protected specimen brushing, used a special catheter that keeps bacteria from the mouth and throat from contaminating the samples taken in the airways. Suspicion of such contamination has kept some researchers from fully accepting the results of previous lung microbiome research. So to test for this contamination, the researchers took one sample on a brush held in the middle of the airway and the rest using brushes that they gently touched to the airway wall. The researchers got other samples through bronchoalveolar lavage, in which they squirt a small amount of fluid into the deepest part of the lung and suction it back into the bronchoscope, bringing microbes along with it. They then analyzed the bacterial DNA found in all these samples. “We found no evidence of upper respiratory tract bacteria in these contamination control specimens,” says Dickson. “This reassured us that the rest of our samples truly reflected lung bacteria and not just contamination from the procedure” brought in by the bronchoscope as it passed through the throat. Taken together, the results suggest bronchoscope-based techniques can be used to study the lung microbiome—in sickness and in health. “The lungs are our largest interface with the outside environment, with 70 square meters of surface area,” says Dickson. “That’s 30 times the size of the skin and twice the size of the gastrointestinal tract. And this study confirms that they’re under constant bombardment by diverse communities of bacteria.” The researchers emphasize that these volunteers were healthy and had no symptoms that suggested pneumonia or other respiratory disease. “These volunteers were as healthy as you or me,” Dickson says. “We are probably all aspirating small amounts of bacteria constantly, and so long as our immune system is intact, they rarely make us sick.” Microaspiration in healthy people has been observed for nearly a century in studies using medical imaging techniques. “We’ve known about the existence of microaspiration for decades,” says Dickson. “But this is the first time we’ve been able to find its ecologic fingerprint.” Next steps in the research will include what happens in people who have problems with the elimination part of this equation. Inability to cough irritants out of the lung, or to carry them out through the sweeping action of hairlike cilia on lung cell surfaces, could lead to more microbes staying longer in the lungs than normal. And that could lead to a higher risk of lung infection. Such research could lead to better understanding of the lung microbiome’s importance in conditions such as chronic obstructive pulmonary disease, cystic fibrosis, and the types of lung failure seen in intensive care units. “If healthy lungs are like Antarctica—where conditions aren’t good for reproduction— then diseased lungs are more like a tropical island, where lower rates of elimination and altered environmental conditions permit the persistence and reproduction of certain bacteria,” he says. Dickson also thinks it would be interesting to study how the lung microbiome changes when a person has a viral infection that causes the upper respiratory tract to produce more nasal secretions. “I certainly look at my kids with their constantly runny noses and wonder if their lung microbiome looks more ‘nasal’ than ‘oral.'” And as researchers begin to uncover the impact of common medications such as antibiotics and proton pump inhibitors on the microbiome in the digestive system, he notes that it’s not unreasonable to think that these drugs also affect the lung microbiome. He and colleagues have already found evidence that the lungs are filled with gut microbes in critically ill patients. The research was sponsored by the National Institutes of Health and the Department of Veterans Affairs, as well as the Michigan Institute for Clinical & Health Research, the U-M Medical School’s Host Microbiome Initiative, and the Michigan Center for Integrative Research in Critical Care.


News Article | October 27, 2016
Site: www.eurekalert.org

Only 92 gold-standard studies in 20 years for heart emergency that happens 535,000 times a year in US ANN ARBOR, Mich. -- Hundreds of thousands of times a year in this country, a heart stops suddenly, when the electrical signals that keep it beating go tragically haywire. It's called a cardiac arrest, and only one in 10 people survive it, whether it happens on a city street, a golf course or a hospital floor. But despite the fact that cardiac arrest kills ten times more people than breast cancer, new research shows a huge lack of studies aimed at improving care and survival. Over the last 20 years, a University of Michigan-led team found, only 92 gold-standard clinical trials have been done on the immediate treatment of cardiac arrest. They report their results, which are based on an exhaustive review of the medical literature, in a paper published online in Circulation: Cardiovascular Quality and Outcomes. The randomized clinical trials that have been done on cardiac arrest involved just over 64,000 patients. Less than five studies a year have published their results. And most tested drugs and devices rather than ways to improve the system of caring for cardiac arrest, from bystanders to ambulance crews to hospitals. "What we found in a nutshell was a striking paucity of randomized clinical trials relative to the burden of cardiac arrest in this country," says Shashank S. Sinha, M.D., M.Sc., a cardiovascular medicine fellow at the U-M Medical School. "We estimate that only 2.5 such trials have been done for every 10,000 out-of-hospital cardiac arrests, and the number is even lower for in-hospital cardiac arrests." By comparison, he says, each year there are 25 to 86 times more clinical trials published for heart failure, heart attack and stroke than for cardiac arrest. Sinha performed the study with U-M co-authors who include Brahmajee K. Nallamothu, M.D., M.P.H., a member of an Institute of Medicine panel that called for action on cardiac arrest, and Robert W. Neumar, M.D., Ph.D., the chair of the American Heart Association's emergency heart care committee who helped create new cardiac arrest treatment guidelines. A colleague from the Mid America Heart Institute, Paul S. Chan, M.D., M.Sc., also contributed. Chan is also Chair of Science for the American Heart Association's Get With The Guidelines-Resuscitation registry for in-hospital cardiac arrest. The review did find that the pace of trials on cardiac arrest has picked up in the last five years, a hopeful sign that more can be done. The researchers evaluated more than 5,000 published medical journal articles and abstracts, but most did not meet the standard needed to draw specific conclusions about the effectiveness of treatment options. "Cardiac arrests remain a significant public health need worldwide, and the limited progress in improving poor survival in the U.S. and globally may be due to inadequate research," says Sinha. "We need to move the needle." He notes that the recent IOM report, and the AHA's recent update to guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiac care, appear to be building momentum for further action on cardiac arrest. The new paper spotlights areas where research on cardiac arrest is most lacking, including protocols for emergency care, post-arrest care, and studies of long-term survival and functional outcomes. Many of the trials highlighted only followed patients through the return of spontaneous circulation, or the restarting of normal heart rhythm. Some studied whether the patients survived long enough to be discharged from the hospital. But what happens to survivors after that, for the days, months and years that follow, is largely unstudied. Another potential area for research to improve cardiac arrest care is standardizing how researchers measure the outcomes of care, including patient-centered things like returning to work or having a reasonable quality of life. Sinha notes that most of the best studies on cardiac arrest have been done outside the U.S. - suggesting a major opportunity for funding agencies and organizations to support new trials. While new drugs and automated CPR devices used while a cardiac arrest is under way should be studied, he says, there's a "compelling opportunity" to study immediate post-arrest care. Better research on processes of care, which could lead to standardization and even accreditation of hospital care, is sorely needed, he says. Perhaps one day, cardiac arrest care could reach the place that heart attack care already has. The new review did not include studies of public-health interventions such as installation of automated external defibrillators or AEDs. It also excluded studies on infants and children. In addition to Sinha, Nallamothu, Neumar and Chan, the paper's authors are Devraj Sukul, M.D., John J. Lazarus, M.D., Ph.D., and Vivek Polavarapu, B.S. All except Chan and Neumar are members of the Frankel Cardiovascular Center and Department of Internal Medicine's Division of Cardiology. Neumar is chair of the U-M Department of Emergency Medicine. Sinha and Nallamothu are members of the U-M Institute for Healthcare Policy and Innovation, and Sinha, Neumar and Nallamothu are members of the Michigan Center for Integrative Research in Critical Care. Nallamothu is also affiliate with the VA Ann Arbor Healthcare System. The research was supported by the National Institutes of Health (HL007853, HL123980, HL091606, HL123227), the VA Health Services Research and Development Program and the American Heart Association.


PubMed | Wayne State University and Michigan Center for Integrative Research in Critical Care
Type: Journal Article | Journal: Langmuir : the ACS journal of surfaces and colloids | Year: 2016

The self-assembly of nanoparticles (NPs) is essential for emerging dispersion-based energy-conscious technologies. Of particular interest are micro- and macro-scale self-organizing superstructures that can bridge 2D/3D processing scales. Here we report the spontaneous assembly of CdTe NPs within an aqueous microdroplet suspended in soybean oil. The gradual diffusion of the water into the surrounding medium results in shrinking of the microdroplet, and a concomitant formation of branched assemblies from CdTe NPs that evolve in size from 50 m to 1000 m. The fractal dimension of NP assemblies increases from 1.7 to 1.9 during the assembly process. We found that constituents of the soybean oil enter the aqueous solution across the microdroplet interface and affect NP assembly. The obtained NP dendrites can be further altered morphologically by illumination with light that results in the disassembly of the NP dendrites. The use of this microheterogeneous dispersion platform with partially soluble hydrophilic and hydrophobic solvents highlights the sensitivity of the NP assembly process to environment and presents an opportunity to explore droplet-confined NP assembly.


PubMed | Michigan Center for Integrative Research in Critical Care, Harbin Institute of Technology and Northwestern Polytechnical University
Type: Journal Article | Journal: ACS nano | Year: 2016

Beam steering devices represent an essential part of an advanced optics toolbox and are needed in a spectrum of technologies ranging from astronomy and agriculture to biosensing and networked vehicles. Diffraction gratings with strain-tunable periodicity simplify beam steering and can serve as a foundation for light/laser radar (LIDAR/LADAR) components of robotic systems. However, the mechanical properties of traditional materials severely limit the beam steering angle and cycle life. The large strain applied to gratings can severely impair the device performance both in respect of longevity and diffraction pattern fidelity. Here, we show that this problem can be resolved using micromanufactured kirigami patterns from thin film nanocomposites based on high-performance stiff plastics, metals, and carbon nanotubes, etc. The kirigami pattern of microscale slits reduces the stochastic concentration of strain in stiff nanocomposites including those made by layer-by-layer assembly (LBL). The slit patterning affords reduction of strain by 2 orders of magnitude for stretching deformation and consequently enables reconfigurable optical gratings with over a 100% range of period tunability. Elasticity of the stiff nanocomposites and plastics makes possible cyclic reconfigurability of the grating with variable time constant that can also be referred to as 4D kirigami. High-contrast, sophisticated diffraction patterns with as high as fifth diffraction order can be obtained. The angular range of beam steering can be as large as 6.5 for a 635 nm laser beam compared to 1 in surface-grooved elastomer gratings and 0.02 in MEMS gratings. The versatility of the kirigami patterns, the diversity of the available nanocomposite materials, and their advantageous mechanical properties of the foundational materials open the path for engineering of reconfigurable optical elements in LIDARs essential for autonomous vehicles and other optical devices with spectral range determined by the kirigami periodicity.

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