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Zhugayevych A.,Los Alamos National Laboratory | Zhugayevych A.,Skolkovo Institute of Science and Technology | Tretiak S.,Los Alamos National Laboratory
Annual Review of Physical Chemistry | Year: 2015

We review recent progress in the modeling of organic solar cells and photovoltaic materials, as well as discuss the underlying theoretical methods with an emphasis on dynamical electronic processes occurring in organic semiconductors. The key feature of the latter is a strong electron-phonon interaction, making the evolution of electronic and structural degrees of freedom inseparable. We discuss commonly used approaches for first-principles modeling of this evolution, focusing on a multiscale framework based on the Holstein-Peierls Hamiltonian solved via polaron transformation. A challenge for both theoretical and experimental investigations of organic solar cells is the complex multiscale morphology of these devices. Nevertheless, predictive modeling of photovoltaic materials and devices is attainable and is rapidly developing, as reviewed here. © 2015 by Annual Reviews. All rights reserved. Source

Yin H.,Massachusetts Institute of Technology | Xue W.,Massachusetts Institute of Technology | Chen S.,Massachusetts Institute of Technology | Bogorad R.L.,Massachusetts Institute of Technology | And 8 more authors.
Nature Biotechnology | Year: 2014

We demonstrate CRISPR-Cas9-mediated correction of a Fah mutation in hepatocytes in a mouse model of the human disease hereditary tyrosinemia. Delivery of components of the CRISPR-Cas9 system by hydrodynamic injection resulted in initial expression of the wild-type Fah protein in ~1/41/250 liver cells. Expansion of Fah-positive hepatocytes rescued the body weight loss phenotype. Our study indicates that CRISPR-Cas9-mediated genome editing is possible in adult animals and has potential for correction of human genetic diseases. © 2014 Nature America, Inc. All rights reserved. Source

Leo D.,Italian Institute of Technology | Gainetdinov R.R.,Italian Institute of Technology | Gainetdinov R.R.,Skolkovo Institute of Science and Technology
Cell and Tissue Research | Year: 2013

Attention-deficit hyperactivity disorder (ADHD) is a developmental disorder characterized by symptoms of inattention, impulsivity and hyperactivity that adversely affect many aspects of life. Whereas the etiology of ADHD remains unknown, growing evidence indicates a genetic involvement in the development of this disorder. The brain circuits associated with ADHD are rich in monoamines, which are involved in the mechanism of action of psychostimulants and other medications used to treat this disorder. Dopamine (DA) is believed to play a major role in ADHD but other neurotransmitters are certainly also involved. Genetically modified mice have become an indispensable tool used to analyze the contribution of genetic factors in the pathogenesis of human disorders. Although rodent models cannot fully recapitulate complex human psychiatric disorders such as ADHD, transgenic mice offer an opportunity to directly investigate in vivo the specific roles of novel candidate genes identified in ADHD patients. Several knock-out and transgenic mouse models have been proposed as ADHD models, mostly based on targeting genes involved in DA transmission, including the gene encoding the dopamine transporter (DAT1). These mutant models provided an opportunity to evaluate the contribution of dopamine-related processes to brain pathology, to dissect the neuronal circuitry and molecular mechanisms involved in the antihyperkinetic action of psychostimulants and to evaluate novel treatments for ADHD. New transgenic models mouse models targeting other genes have recently been proposed for ADHD. Here, we discuss the recent advances and pitfalls in modeling ADHD endophenotypes in genetically altered animals. © 2013 Springer-Verlag Berlin Heidelberg. Source

Perebeinos V.,IBM | Perebeinos V.,Skolkovo Institute of Science and Technology | Tersoff J.,IBM
Nano Letters | Year: 2014

In carbon nanotube transistors, typically part of the nanotube is covered by a metal contact. This covered region plays an important role due to the significant electron transfer length. Here we predict that capillary and van der Waals forces cause the nanotube to deform or even collapse under the metal. Nanotubes are known to collapse when their diameters are above some critical value around 4 nm. Under the metal, we find that spontaneous collapse occurs for diameters down to ∼1.5-1.6 nm, close to the range used in high-performance transistors. Even at smaller diameters, we find surprisingly large deformations that could significantly affect the electronic structure. © 2014 American Chemical Society. Source

Agency: Cordis | Branch: H2020 | Program: RIA | Phase: PROTEC-1-2014 | Award Amount: 2.36M | Year: 2015

The smooth functioning of the European economy and the welfare of its citizens depends upon an ever-growing set of services and facilities that are reliant on space and ground based infrastructure. Examples include communications (radio, TV, mobile phones), navigation of aircraft and private transport via GPS, and service industries (e.g. banking). These services, however, can be adversely affected by the space weather hazards. The forecasting of space weather hazards, driven by the dynamical processes originating on the sun, is critical to the mitigation of their negative effects. This proposal brings world leading groups in the fields of space physics and systems science in order to develop an accurate and reliable forecast system for space weather. It combines their individual strengths to significantly improve the current modelling capabilities within Europe and to produce a set of forecast tools to accurately predict the occurrence and severity of space weather events. Within project PROGRESS we will develop an European tool to forecast the solar wind parameters just upstream of the Earths magnetosphere. We will develop a comprehensive set of forecasting tools for geomagnetic indices. We will combine the most accurate data based forecast of electron fluxes at GEO with the most comprehensive physics based model of the radiation belts currently available to deliver a reliable forecast of radiation environment in the radiation belts. This project will deliver these individual forecast tools together with a unified tool that combines the forecasting tools with the prediction of the solar wind parameters at L1 to substantially increase the lead-time of space weather forecasts.

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