ALBERT

Description: Synthetic matrices emulating the physicochemical properties of tissue-specific ECMs are being developed at a rapid pace to regulate stem cell fate. Biomaterials containing calcium phosphate (CaP) moieties have been shown to support osteogenic differentiation of stem and progenitor cells and bone tissue formation. By using a mineralized synthetic matrix mimicking...

Description: Author(s): S. Das Sarma and E. H. Hwang We study theoretically the relative importance of short-range disorder in determining the low-temperature two-dimensional (2D) mobility in GaAs-based structures with respect to Coulomb disorder, which is known to be the dominant disorder in semiconductor systems. We give results for unscreened and s... [Phys. Rev. B 89, 121413] Published Fri Mar 28, 2014

Description: In higher eukaryotes, one of the two arginyl-tRNA synthetases (ArgRSs) has evolved to have an extended N-terminal domain that plays a crucial role in protein synthesis and cell growth and in integration into the multisynthetase complex (MSC). Here, we report a crystal structure of the MSC subcomplex comprising ArgRS, glutaminyl-tRNA...

Description: Author(s): S. Das Sarma, E. H. Hwang, K. Kechedzhi, and L. A. Tracy Combining experimental data, numerical transport calculations, and theoretical analysis, we study the temperature-dependent resistivity of high-mobility two-dimensional (2D) Si MOSFETs to search for signatures of weak localization induced quantum corrections in the effective metallic regime above th... [Phys. Rev. B 90, 125410] Published Mon Sep 08, 2014

Description: A paradigm shift for implantable medical devices lies at the confluence between regenerative medicine, where materials remodel and integrate in the biological milieu, and technology, through the use of recently developed material platforms based on biomaterials and bioresorbable technologies such as optics and electronics. The union of materials and technology...

Description: Author(s): S. Das Sarma and E. H. Hwang Low-disorder and high-mobility two-dimensional (2D) electron (or hole) systems confined in semiconductor heterostructures undergo an apparent metal-insulator transition (MIT) at low temperatures as the carrier density (n) is varied. In some situations, the 2D MIT can be caused at a fixed low carrier... [Phys. Rev. B 89, 235423] Published Wed Jun 18, 2014

Description: Here, we report a resistance mechanism that is induced through the modulation of 16S ribosomal RNA (rRNA) processing on the exposure of Escherichia coli cells to aminoglycoside antibiotics. We observed decreased expression levels of RNase G associated with increased RNase III activity on rng mRNA in a subgroup of E. coli isolates that transiently acquired resistance to low levels of kanamycin or streptomycin. Analyses of 16S rRNA from the aminoglycoside-resistant E. coli cells, in addition to mutagenesis studies, demonstrated that the accumulation of 16S rRNA precursors containing 3–8 extra nucleotides at the 5’ terminus, which results from incomplete processing by RNase G, is responsible for the observed aminoglycoside resistance. Chemical protection, mass spectrometry analysis and cell-free translation assays revealed that the ribosomes from rng -deleted E. coli have decreased binding capacity for, and diminished sensitivity to, streptomycin and neomycin, compared with wild-type cells. It was observed that the deletion of rng had similar effects in Salmonella enterica serovar Typhimurium strain SL1344. Our findings suggest that modulation of the endoribonucleolytic activity of RNase III and RNase G constitutes a previously uncharacterized regulatory pathway for adaptive resistance in E. coli and related gram-negative bacteria to aminoglycoside antibiotics.

Description: Metabolism and ageing are intimately linked. Compared with ad libitum feeding, dietary restriction consistently extends lifespan and delays age-related diseases in evolutionarily diverse organisms. Similar conditions of nutrient limitation and genetic or pharmacological perturbations of nutrient or energy metabolism also have longevity benefits. Recently, several metabolites have been identified that modulate ageing; however, the molecular mechanisms underlying this are largely undefined. Here we show that alpha-ketoglutarate (alpha-KG), a tricarboxylic acid cycle intermediate, extends the lifespan of adult Caenorhabditis elegans. ATP synthase subunit beta is identified as a novel binding protein of alpha-KG using a small-molecule target identification strategy termed drug affinity responsive target stability (DARTS). The ATP synthase, also known as complex V of the mitochondrial electron transport chain, is the main cellular energy-generating machinery and is highly conserved throughout evolution. Although complete loss of mitochondrial function is detrimental, partial suppression of the electron transport chain has been shown to extend C. elegans lifespan. We show that alpha-KG inhibits ATP synthase and, similar to ATP synthase knockdown, inhibition by alpha-KG leads to reduced ATP content, decreased oxygen consumption, and increased autophagy in both C. elegans and mammalian cells. We provide evidence that the lifespan increase by alpha-KG requires ATP synthase subunit beta and is dependent on target of rapamycin (TOR) downstream. Endogenous alpha-KG levels are increased on starvation and alpha-KG does not extend the lifespan of dietary-restricted animals, indicating that alpha-KG is a key metabolite that mediates longevity by dietary restriction. Our analyses uncover new molecular links between a common metabolite, a universal cellular energy generator and dietary restriction in the regulation of organismal lifespan, thus suggesting new strategies for the prevention and treatment of ageing and age-related diseases.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4263271/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4263271/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chin, Randall M -- Fu, Xudong -- Pai, Melody Y -- Vergnes, Laurent -- Hwang, Heejun -- Deng, Gang -- Diep, Simon -- Lomenick, Brett -- Meli, Vijaykumar S -- Monsalve, Gabriela C -- Hu, Eileen -- Whelan, Stephen A -- Wang, Jennifer X -- Jung, Gwanghyun -- Solis, Gregory M -- Fazlollahi, Farbod -- Kaweeteerawat, Chitrada -- Quach, Austin -- Nili, Mahta -- Krall, Abby S -- Godwin, Hilary A -- Chang, Helena R -- Faull, Kym F -- Guo, Feng -- Jiang, Meisheng -- Trauger, Sunia A -- Saghatelian, Alan -- Braas, Daniel -- Christofk, Heather R -- Clarke, Catherine F -- Teitell, Michael A -- Petrascheck, Michael -- Reue, Karen -- Jung, Michael E -- Frand, Alison R -- Huang, Jing -- DP2 OD008398/OD/NIH HHS/ -- P01 HL028481/HL/NHLBI NIH HHS/ -- P40 OD010440/OD/NIH HHS/ -- T32 CA009120/CA/NCI NIH HHS/ -- T32 GM007104/GM/NIGMS NIH HHS/ -- T32 GM007185/GM/NIGMS NIH HHS/ -- T32 GM008496/GM/NIGMS NIH HHS/ -- England -- Nature. 2014 Jun 19;510(7505):397-401. doi: 10.1038/nature13264. Epub 2014 May 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2]. ; 1] Department of Human Genetics, University of California Los Angeles, Los Angeles, California 90095, USA [2]. ; 1] Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA [2]. ; Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Surgery, University of California Los Angeles, Los Angeles, California 90095, USA. ; Small Molecule Mass Spectrometry Facility, FAS Division of Science, Harvard University, Cambridge, Massachusetts 02138, USA. ; Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037, USA. ; Pasarow Mass Spectrometry Laboratory, Department of Psychiatry and Biobehavioral Sciences and Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Environmental Health Sciences, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA. ; 1] Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA [2] UCLA Metabolomics Center, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Human Genetics, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24828042" target="_blank"〉PubMed〈/a〉

Description: Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet's temperature is much lower, 〈60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gould, A -- Udalski, A -- Shin, I-G -- Porritt, I -- Skowron, J -- Han, C -- Yee, J C -- Kozlowski, S -- Choi, J-Y -- Poleski, R -- Wyrzykowski, L -- Ulaczyk, K -- Pietrukowicz, P -- Mroz, P -- Szymanski, M K -- Kubiak, M -- Soszynski, I -- Pietrzynski, G -- Gaudi, B S -- Christie, G W -- Drummond, J -- McCormick, J -- Natusch, T -- Ngan, H -- Tan, T-G -- Albrow, M -- DePoy, D L -- Hwang, K-H -- Jung, Y K -- Lee, C-U -- Park, H -- Pogge, R W -- Abe, F -- Bennett, D P -- Bond, I A -- Botzler, C S -- Freeman, M -- Fukui, A -- Fukunaga, D -- Itow, Y -- Koshimoto, N -- Larsen, P -- Ling, C H -- Masuda, K -- Matsubara, Y -- Muraki, Y -- Namba, S -- Ohnishi, K -- Philpott, L -- Rattenbury, N J -- Saito, To -- Sullivan, D J -- Sumi, T -- Suzuki, D -- Tristram, P J -- Tsurumi, N -- Wada, K -- Yamai, N -- Yock, P C M -- Yonehara, A -- Shvartzvald, Y -- Maoz, D -- Kaspi, S -- Friedmann, M -- New York, N.Y. -- Science. 2014 Jul 4;345(6192):46-9. doi: 10.1126/science.1251527.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA. ; Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland. ; Turitea Observatory, Palmerston North, New Zealand. ; Department of Physics, Chungbuk National University, Cheongju 371-763, Republic of Korea. cheongho@astroph.chungbuk.ac.kr. ; Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. ; Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA. Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland. ; Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK. ; Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA. Universidad de Concepcion, Departamento de Astronomia, Casilla 160-C, Concepcion, Chile. ; Auckland Observatory, Auckland, New Zealand. ; Possum Observatory, Patutahi, New Zealand. ; Farm Cove Observatory, Centre for Backyard Astrophysics, Pakuranga, Auckland, New Zealand. ; Possum Observatory, Patutahi, New Zealand. Auckland University of Technology, Auckland, New Zealand. ; Perth Exoplanet Survey Telescope, Perth, Australia. ; Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch, New Zealand. ; Department of Physics and Astronomy, Texas A&M University, College Station, TX 77843-4242, USA. ; Department of Physics, Chungbuk National University, Cheongju 371-763, Republic of Korea. ; Korea Astronomy and Space Science Institute, Daejeon 305-348, Republic of Korea. ; Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601, Japan. ; University of Notre Dame, Department of Physics, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670, USA. ; Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland, New Zealand. ; Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001, New Zealand. ; Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232, Japan. ; Department of Earth and Space Science, Osaka University, Osaka 560-0043, Japan. ; Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001, New Zealand. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK. ; Nagano National College of Technology, Nagano 381-8550, Japan. ; Department of Earth, Ocean and Atmospheric Sciences, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada. ; Tokyo Metropolitan College of Aeronautics, Tokyo 116-8523, Japan. ; School of Chemical and Physical Sciences, Victoria University, Wellington, New Zealand. ; Mount John University Observatory, Post Office Box 56, Lake Tekapo 8770, New Zealand. ; Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555, Japan. ; School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978, Israel.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24994642" target="_blank"〉PubMed〈/a〉

Description: Author(s): Edwin Barnes, E. H. Hwang, R. E. Throckmorton, and S. Das Sarma Many-body electron-electron interaction effects are theoretically considered in monolayer graphene from a continuum effective field-theoretic perspective by going beyond the standard leading-order single-loop perturbative renormalization group (RG) analysis. Given that the effective (bare) coupling ... [Phys. Rev. B 89, 235431] Published Wed Jun 25, 2014