Πέμπτη 13 Αυγούστου 2020

 A molecular mediator for reductive concerted proton-electron transfers via electrocatalysis

Electrocatalytic approaches to the activation of unsaturated substrates via reductive concerted proton-electron transfer (CPET) must overcome competing, often kinetically dominant hydrogen evolution. We introduce the design of a molecular mediator for electrochemically triggered reductive CPET through the synthetic integration of a Brønsted acid and a redox mediator. Cathodic reduction at the cobaltocenium redox mediator substantially weakens the homolytic nitrogen-hydrogen bond strength of a Brønsted...
Science: Current Issue
Thu Aug 13, 2020 20:40
News at a glance
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Thu Aug 13, 2020 20:40
Advancing Li-air batteries
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Thu Aug 13, 2020 20:40
Antibodies may curb pandemic before vaccines
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Thu Aug 13, 2020 20:40
Social contact and reconciliation
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Thu Aug 13, 2020 20:40
For science in Latin America, 'a fascinating challenge
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Thu Aug 13, 2020 20:40
SARS-CoV-2 infection protects against rechallenge in rhesus macaques
An understanding of protective immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for vaccine and public health strategies aimed at ending the global coronavirus disease 2019 (COVID-19) pandemic. A key unanswered question is whether infection with SARS-CoV-2 results in protective immunity against reexposure. We developed a rhesus macaque model of SARS-CoV-2 infection and observed that macaques had high viral loads in the upper and lower respiratory tract, humoral...
Science: Current Issue
Thu Aug 13, 2020 20:40
Looking for the light in Haiti
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Thu Aug 13, 2020 20:40
Vaccine nationalism's politics
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Thu Aug 13, 2020 20:40
Africa's pandemic puzzle: why so few cases and deaths?
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Thu Aug 13, 2020 20:40
Autoimmunity promotor
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Thu Aug 13, 2020 20:40
Fed-up archaeologists aim to fix field schools' party culture
Science: Current Issue
Thu Aug 13, 2020 20:40
Huntingtons disease alters human neurodevelopment
Although Huntington’s disease is a late-manifesting neurodegenerative disorder, both mouse studies and neuroimaging studies of presymptomatic mutation carriers suggest that Huntington’s disease might affect neurodevelopment. To determine whether this is actually the case, we examined tissue from human fetuses (13 weeks gestation) that carried the Huntington’s disease mutation. These tissues showed clear abnormalities in the developing cortex, including mislocalization of mutant huntingtin and junctional...
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Thu Aug 13, 2020 20:40
Don't crush that ant--it could plant a wildflower
Science: Current Issue
Thu Aug 13, 2020 20:40
Observation of small Fermi pockets protected by clean CuO2 sheets of a high-Tc superconductor
In cuprate superconductors with high critical transition temperature (Tc), light hole-doping to the parent compound, which is an antiferromagnetic Mott insulator, has been predicted to lead to the formation of small Fermi pockets. These pockets, however, have not been observed. Here, we investigate the electronic structure of the five-layered Ba2Ca4Cu5O10(F,O)2, which has inner copper oxide (CuO2) planes with extremely low disorder, and find small Fermi pockets centered at (/2, /2) of the Brillouin...
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Thu Aug 13, 2020 20:40
Lucky strike
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Thu Aug 13, 2020 20:40
Building social cohesion between Christians and Muslims through soccer in post-ISIS Iraq
Can intergroup contact build social cohesion after war? I randomly assigned Iraqi Christians displaced by the Islamic State of Iraq and Syria (ISIS) to an all-Christian soccer team or to a team mixed with Muslims. The intervention improved behaviors toward Muslim peers: Christians with Muslim teammates were more likely to vote for a Muslim (not on their team) to receive a sportsmanship award, register for a mixed team next season, and train with Muslims 6 months after the intervention. The intervention...
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Thu Aug 13, 2020 20:40
Distorting science, putting water at risk
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Thu Aug 13, 2020 20:40
Heterogeneity and herd immunity
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Thu Aug 13, 2020 20:40
Can playing together help us live together?
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Thu Aug 13, 2020 20:40
Bedding of grass and ashes
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Thu Aug 13, 2020 20:40
Marine food webs destabilized
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Thu Aug 13, 2020 20:40
Plants take the splice to the fight
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Thu Aug 13, 2020 20:40
An early start to Huntington's disease
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Thu Aug 13, 2020 20:40
Early vision matures
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Thu Aug 13, 2020 20:40
Designing a wider superelastic window
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Thu Aug 13, 2020 20:40
Divergent synthesis of complex diterpenes through a hybrid oxidative approach
Polycyclic diterpenes exhibit many important biological activities, but de novo synthetic access to these molecules is highly challenging because of their structural complexity. Semisynthetic access has also been limited by the lack of chemical tools for scaffold modifications. We report a chemoenzymatic platform to access highly oxidized diterpenes by a hybrid oxidative approach that strategically combines chemical and enzymatic oxidation methods. This approach allows for selective oxidations of...
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Thu Aug 13, 2020 20:40
The importins of pain
Science: Current Issue
Thu Aug 13, 2020 20:40
BAF restricts cGAS on nuclear DNA to prevent innate immune activation
The appearance of DNA in the cytosol is perceived as a danger signal that stimulates potent immune responses through cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS). How cells regulate the activity of cGAS toward self-DNA and guard against potentially damaging autoinflammatory responses is a fundamental biological question. Here, we identify barrier-to-autointegration factor 1 (BAF) as a natural opponent of cGAS activity on genomic self-DNA. We show that BAF dynamically outcompetes...
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Thu Aug 13, 2020 20:40
A coexistence that CuO2 planes can see
Science: Current Issue
Thu Aug 13, 2020 20:40
Importin {alpha}3 regulates chronic pain pathways in peripheral sensory neurons
How is neuropathic pain regulated in peripheral sensory neurons? Importins are key regulators of nucleocytoplasmic transport. In this study, we found that importin α3 (also known as karyopherin subunit alpha 4) can control pain responsiveness in peripheral sensory neurons in mice. Importin α3 knockout or sensory neuron–specific knockdown in mice reduced responsiveness to diverse noxious stimuli and increased tolerance to neuropathic pain. Importin α3–bound c-Fos and importin α3–deficient neurons...
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Thu Aug 13, 2020 20:40
Michael Soule (1936-2020)
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Thu Aug 13, 2020 20:40
Mitochondrial dynamics in postmitotic cells regulate neurogenesis
The conversion of neural stem cells into neurons is associated with the remodeling of organelles, but whether and how this is causally linked to fate change is poorly understood. We examined and manipulated mitochondrial dynamics during mouse and human cortical neurogenesis. We reveal that shortly after cortical stem cells have divided, daughter cells destined to self-renew undergo mitochondrial fusion, whereas those that retain high levels of mitochondria fission become neurons. Increased mitochondria...
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Thu Aug 13, 2020 20:40
How it all ends
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Thu Aug 13, 2020 20:40
Interrupted--again
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Thu Aug 13, 2020 20:40
Science meets politics
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Thu Aug 13, 2020 20:40
Delivering protons with electrons
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Thu Aug 13, 2020 20:40
Retraction
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Thu Aug 13, 2020 20:40
An elusive pocket
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Thu Aug 13, 2020 20:40
Controlling the coronavirus narrative
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Thu Aug 13, 2020 20:40
Inflexible webs
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Thu Aug 13, 2020 20:40
Dismantling systemic racism in science
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Thu Aug 13, 2020 20:40
PERKing up neurons without toxicity
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Thu Aug 13, 2020 20:40
Untapped resources for medical research
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Thu Aug 13, 2020 20:40
Fermenting coevolution
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Thu Aug 13, 2020 20:40
The carbon gain in restored logged forest
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Thu Aug 13, 2020 20:40
The thymus X factor
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Thu Aug 13, 2020 20:40
Trio of enzymes power divergent synthesis
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Thu Aug 13, 2020 20:40
Philanthropy--or tax-exempt lobbying?
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Thu Aug 13, 2020 20:40
A loose BAF puts its foot on the cGAS
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Thu Aug 13, 2020 20:40
An uncuttable foam
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Thu Aug 13, 2020 20:40
Strength in numbers
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Thu Aug 13, 2020 20:40
Binding mechanisms of therapeutic antibodies to human CD20
Monoclonal antibodies (mAbs) targeting human antigen CD20 (cluster of differentiation 20) constitute important immunotherapies for the treatment of B cell malignancies and autoimmune diseases. Type I and II therapeutic mAbs differ in B cell binding properties and cytotoxic effects, reflecting differential interaction mechanisms with CD20. Here we present 3.7- to 4.7-angstrom cryo–electron microscopy structures of full-length CD20 in complexes with prototypical type I rituximab and ofatumumab and...
Science: Current Issue
Thu Aug 13, 2020 20:40
Mitochondrial dynamics and cell fate
Science: Current Issue
Thu Aug 13, 2020 20:40
DNA vaccine protection against SARS-CoV-2 in rhesus macaques
The global coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made the development of a vaccine a top biomedical priority. In this study, we developed a series of DNA vaccine candidates expressing different forms of the SARS-CoV-2 spike (S) protein and evaluated them in 35 rhesus macaques. Vaccinated animals developed humoral and cellular immune responses, including neutralizing antibody titers at levels comparable to those found...
Science: Current Issue
Thu Aug 13, 2020 20:40
Temperature-stable superelasticity
Science: Current Issue
Thu Aug 13, 2020 20:40
Primary exposure to SARS-CoV-2 protects against reinfection in rhesus macaques
Coronavirus disease 2019 (COVID-19), which is caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic. It is unclear whether convalescing patients have a risk of reinfection. We generated a rhesus macaque model of SARS-CoV-2 infection that was characterized by interstitial pneumonia and systemic viral dissemination mainly in the respiratory and gastrointestinal tracts. Rhesus macaques reinfected with the identical SARS-CoV-2 strain during...
Science: Current Issue
Thu Aug 13, 2020 20:40
Ozone pollution threatens biodiversity
Science: Current Issue
Thu Aug 13, 2020 20:40
Trophic pyramids reorganize when food web architecture fails to adjust to ocean change
As human activities intensify, the structures of ecosystems and their food webs often reorganize. Through the study of mesocosms harboring a diverse benthic coastal community, we reveal that food web architecture can be inflexible under ocean warming and acidification and unable to compensate for the decline or proliferation of taxa. Key stabilizing processes, including functional redundancy, trophic compensation, and species substitution, were largely absent under future climate conditions. A trophic...
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Thu Aug 13, 2020 20:40
A second transplant for intestinal disease
Science: Current Issue
Thu Aug 13, 2020 20:40
Active restoration accelerates the carbon recovery of human-modified tropical forests
More than half of all tropical forests are degraded by human impacts, leaving them threatened with conversion to agricultural plantations and risking substantial biodiversity and carbon losses. Restoration could accelerate recovery of aboveground carbon density (ACD), but adoption of restoration is constrained by cost and uncertainties over effectiveness. We report a long-term comparison of ACD recovery rates between naturally regenerating and actively restored logged tropical forests. Restoration...
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Thu Aug 13, 2020 20:40
Making chemistry less precious
Science: Current Issue
Thu Aug 13, 2020 20:40
A mathematical model reveals the influence of population heterogeneity on herd immunity to SARS-CoV-2
Despite various levels of preventive measures, in 2020, many countries have suffered severely from the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Using a model, we show that population heterogeneity can affect disease-induced immunity considerably because the proportion of infected individuals in groups with the highest contact rates is greater than that in groups with low contact rates. We estimate that if R0 =...
Science: Current Issue
Thu Aug 13, 2020 20:40
Neural progenitors disrupted
Science: Current Issue
Thu Aug 13, 2020 20:40
Iron-based superelastic alloys with near-constant critical stress temperature dependence
Shape memory alloys recover their original shape after deformation, making them useful for a variety of specialized applications. Superelastic behavior begins at the critical stress, which tends to increase with increasing temperature for metal shape memory alloys. Temperature dependence is a common feature that often restricts the use of metal shape memory alloys in applications. We discovered an iron-based superelastic alloy system in which the critical stress can be optimized. Our Fe-Mn-Al-Cr-Ni...
Science: Current Issue
Thu Aug 13, 2020 20:40
Prototype DNA vaccines for SARS-CoV-2
Science: Current Issue
Thu Aug 13, 2020 20:40
Fire and grass-bedding construction 200 thousand years ago at Border Cave, South Africa
Early plant use is seldom described in the archaeological record because of poor preservation. We report the discovery of grass bedding used to create comfortable areas for sleeping and working by people who lived in Border Cave at least 200,000 years ago. Sheaves of grass belonging to the broad-leafed Panicoideae subfamily were placed near the back of the cave on ash layers that were often remnants of bedding burned for site maintenance. This strategy is one forerunner of more-complex behavior that...
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Thu Aug 13, 2020 20:40
Immunity from reinfection
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Thu Aug 13, 2020 20:40
New Products
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Thu Aug 13, 2020 20:40
Nuclear transport controls chronic pain
Science: Current Issue
Thu Aug 13, 2020 20:40
Using natures blueprint to expand catalysis with Earth-abundant metals
Numerous redox transformations that are essential to life are catalyzed by metalloenzymes that feature Earth-abundant metals. In contrast, platinum-group metals have been the cornerstone of many industrial catalytic reactions for decades, providing high activity, thermal stability, and tolerance to chemical poisons. We assert that nature’s blueprint provides the fundamental principles for vastly expanding the use of abundant metals in catalysis. We highlight the key physical properties of abundant...
Science: Current Issue
Thu Aug 13, 2020 20:40

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