ALBERT

Description: Author(s): C.-Y. Wen, J. Tersoff, K. Hillerich, M. C. Reuter, J. H. Park, S. Kodambaka, E. A. Stach, and F. M. Ross Nanowire growth in the standard ⟨111⟩ direction is assumed to occur at a planar catalyst-nanowire interface, but recent reports contradict this picture. Here we show that a nonplanar growth interface is, in fact, a general phenomenon. Both III–V and group IV nanowires show a distinct region at the t... [Phys. Rev. Lett. 107, 025503] Published Wed Jul 06, 2011

Description: Author(s): K. W. Schwarz, J. Tersoff, S. Kodambaka, Y.-C. Chou, and F. M. Ross [Phys. Rev. Lett. 107, 265502] Published Fri Dec 23, 2011

Description: Author(s): K. W. Schwarz, J. Tersoff, S. Kodambaka, and F. M. Ross Nanowire growth is generally considered a steady-state process, but oscillatory phenomena are known to often play a fundamental role. Here we identify a natural sequence of distinct growth modes, in two of which the catalyst droplet jumps periodically on and off a crystal facet. The oscillatory mode... [Phys. Rev. Lett. 113, 055501] Published Wed Jul 30, 2014

Description: Real-time observations were made of the shape change from pyramids to domes during the growth of germanium-silicon islands on silicon (001). Small islands are pyramidal in shape, whereas larger islands are dome-shaped. During growth, the transition from pyramids to domes occurs through a series of asymmetric transition states with increasing numbers of highly inclined facets. Postgrowth annealing of pyramids results in a similar shape change process. The transition shapes are temperature dependent and transform reversibly to the final dome shape during cooling. These results are consistent with an anomalous coarsening model for island growth.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ross -- Tromp -- Reuter -- New York, N.Y. -- Science. 1999 Dec 3;286(5446):1931-1934.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉IBM T. J. Watson Research Center, Post Office Box 218, Yorktown Heights, NY 10598, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10583951" target="_blank"〉PubMed〈/a〉

Description: We measured the nucleation and growth kinetics of solid silicon (Si) from liquid gold-silicon (AuSi) catalyst particles as the Si supersaturation increased, which is the first step of the vapor-liquid-solid growth of nanowires. Quantitative measurements agree well with a kinetic model, providing a unified picture of the growth process. Nucleation is heterogeneous, occurring consistently at the edge of the AuSi droplet, yet it is intrinsic and highly reproducible. We studied the critical supersaturation required for nucleation and found no observable size effects, even for systems down to 12 nanometers in diameter. For applications in nanoscale technology, the reproducibility is essential, heterogeneity promises greater control of nucleation, and the absence of strong size effects simplifies process design.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kim, B J -- Tersoff, J -- Kodambaka, S -- Reuter, M C -- Stach, E A -- Ross, F M -- New York, N.Y. -- Science. 2008 Nov 14;322(5904):1070-3. doi: 10.1126/science.1163494.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19008438" target="_blank"〉PubMed〈/a〉

Description: Changes in gene dosage are a major driver of cancer, known to be caused by a finite, but increasingly well annotated, repertoire of mutational mechanisms. This can potentially generate correlated copy-number alterations across hundreds of linked genes, as exemplified by the 2% of childhood acute lymphoblastic leukaemia (ALL) with recurrent amplification of megabase regions of chromosome 21 (iAMP21). We used genomic, cytogenetic and transcriptional analysis, coupled with novel bioinformatic approaches, to reconstruct the evolution of iAMP21 ALL. Here we show that individuals born with the rare constitutional Robertsonian translocation between chromosomes 15 and 21, rob(15;21)(q10;q10)c, have approximately 2,700-fold increased risk of developing iAMP21 ALL compared to the general population. In such cases, amplification is initiated by a chromothripsis event involving both sister chromatids of the Robertsonian chromosome, a novel mechanism for cancer predisposition. In sporadic iAMP21, breakage-fusion-bridge cycles are typically the initiating event, often followed by chromothripsis. In both sporadic and rob(15;21)c-associated iAMP21, the final stages frequently involve duplications of the entire abnormal chromosome. The end-product is a derivative of chromosome 21 or the rob(15;21)c chromosome with gene dosage optimized for leukaemic potential, showing constrained copy-number levels over multiple linked genes. Thus, dicentric chromosomes may be an important precipitant of chromothripsis, as we show rob(15;21)c to be constitutionally dicentric and breakage-fusion-bridge cycles generate dicentric chromosomes somatically. Furthermore, our data illustrate that several cancer-specific mutational processes, applied sequentially, can coordinate to fashion copy-number profiles over large genomic scales, incrementally refining the fitness benefits of aggregated gene dosage changes.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3976272/" 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/PMC3976272/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Li, Yilong -- Schwab, Claire -- Ryan, Sarra L -- Papaemmanuil, Elli -- Robinson, Hazel M -- Jacobs, Patricia -- Moorman, Anthony V -- Dyer, Sara -- Borrow, Julian -- Griffiths, Mike -- Heerema, Nyla A -- Carroll, Andrew J -- Talley, Polly -- Bown, Nick -- Telford, Nick -- Ross, Fiona M -- Gaunt, Lorraine -- McNally, Richard J Q -- Young, Bryan D -- Sinclair, Paul -- Rand, Vikki -- Teixeira, Manuel R -- Joseph, Olivia -- Robinson, Ben -- Maddison, Mark -- Dastugue, Nicole -- Vandenberghe, Peter -- Haferlach, Claudia -- Stephens, Philip J -- Cheng, Jiqiu -- Van Loo, Peter -- Stratton, Michael R -- Campbell, Peter J -- Harrison, Christine J -- 077012/Z/05/Z/Wellcome Trust/United Kingdom -- 088340/Wellcome Trust/United Kingdom -- 093867/Wellcome Trust/United Kingdom -- U10 CA098543/CA/NCI NIH HHS/ -- U10 CA180886/CA/NCI NIH HHS/ -- WT088340MA/Wellcome Trust/United Kingdom -- England -- Nature. 2014 Apr 3;508(7494):98-102. doi: 10.1038/nature13115. Epub 2014 Mar 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK [2]. ; 1] Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne NE2 4HH, UK [2]. ; Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK. ; West Midlands Regional Genetics Laboratory, Birmingham Women's NHS Foundation Trust, Birmingham B15 2TG, UK. ; Wessex Regional Genetics Laboratory, Salisbury NHS Foundation Trust, Salisbury SP2 8BJ, UK. ; Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne NE2 4HH, UK. ; 1] West Midlands Regional Genetics Laboratory, Birmingham Women's NHS Foundation Trust, Birmingham B15 2TG, UK [2] School of Cancer Sciences, University of Birmingham, Birmingham B15 2TT, UK. ; Department of Pathology, The Ohio State University, Columbus, Ohio 43210, USA. ; Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35233, USA. ; Sheffield Diagnostic Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield S10 2TH, UK. ; Cytogenetics Laboratory, Northern Genetics Service, Newcastle upon Tyne NE7 7DN, UK. ; Oncology Cytogenetics, The Christie NHS Foundation Trust, Manchester M20 4BX, UK. ; Regional Cytogenetics Unit, Genetic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Saint Mary's Hospital, Manchester M13 9WL, UK. ; Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX, UK. ; 1] Genetics Department, Portuguese Oncology Institute, Porto University, 4200-072 Porto, Portugal [2] Biomedical Sciences Institute (ICBAS), Porto University, 4200-072 Porto, Portugal. ; Laboratoire d'Hematologie, Genetique des Hemopathies, Hopital Purpan, 31059 Toulouse, France. ; 1] Center for Human Genetics, University Hospital Leuven, 3000 Leuven, Belgium [2] KU Leuven, 3000 Leuven, Belgium. ; MLL Munich Leukemia Laboratory, Munich 81377, Germany. ; 1] Center for Human Genetics, University Hospital Leuven, 3000 Leuven, Belgium [2] KU Leuven, 3000 Leuven, Belgium [3] Department of Electrical Engineering - ESAT, University of Leuven, 3000 Leuven, Belgium. ; 1] Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK [2] Center for Human Genetics, University Hospital Leuven, 3000 Leuven, Belgium [3] KU Leuven, 3000 Leuven, Belgium. ; 1] Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK [2] Department of Haematology, University of Cambridge, Cambridge CB2 2XY, UK [3].〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24670643" target="_blank"〉PubMed〈/a〉

Description: Nanowires are conventionally assumed to grow via the vapor-liquid-solid process, in which material from the vapor is incorporated into the growing nanowire via a liquid catalyst, commonly a low-melting point eutectic alloy. However, nanowires have been observed to grow below the eutectic temperature, and the state of the catalyst remains controversial. Using in situ microscopy, we showed that, for the classic Ge/Au system, nanowire growth can occur below the eutectic temperature with either liquid or solid catalysts at the same temperature. We found, unexpectedly, that the catalyst state depends on the growth pressure and thermal history. We suggest that these phenomena may be due to kinetic enrichment of the eutectic alloy composition and expect these results to be relevant for other nanowire systems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kodambaka, S -- Tersoff, J -- Reuter, M C -- Ross, F M -- New York, N.Y. -- Science. 2007 May 4;316(5825):729-32.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉IBM T. J. Watson Research Center, Yorktown Heights, NY 10598, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17478716" target="_blank"〉PubMed〈/a〉

Description: We have formed compositionally abrupt interfaces in silicon-germanium (Si-Ge) and Si-SiGe heterostructure nanowires by using solid aluminum-gold alloy catalyst particles rather than the conventional liquid semiconductor-metal eutectic droplets. We demonstrated single interfaces that are defect-free and close to atomically abrupt, as well as quantum dots (i.e., Ge layers tens of atomic planes thick) embedded within Si wires. Real-time imaging of growth kinetics reveals that a low solubility of Si and Ge in the solid particle accounts for the interfacial abruptness. Solid catalysts that can form functional group IV nanowire-based structures may yield an extended range of electronic applications.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wen, C-Y -- Reuter, M C -- Bruley, J -- Tersoff, J -- Kodambaka, S -- Stach, E A -- Ross, F M -- New York, N.Y. -- Science. 2009 Nov 27;326(5957):1247-50. doi: 10.1126/science.1178606.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19965471" target="_blank"〉PubMed〈/a〉

Description: In the growth of nanoscale device structures, the ultimate goal is atomic-level precision. By growing III-V nanowires in a transmission electron microscope, we measured the local kinetics in situ as each atomic plane was added at the catalyst-nanowire growth interface by the vapor-liquid-solid process. During growth of gallium phosphide nanowires at typical V/III ratios, we found surprising fluctuations in growth rate, even under steady growth conditions. We correlated these fluctuations with the formation of twin defects in the nanowire, and found that these variations can be suppressed by switching to growth conditions with a low V/III ratio. We derive a growth model showing that this unexpected variation in local growth kinetics reflects the very different supply pathways of the V and III species. The model explains under which conditions the growth rate can be controlled precisely at the atomic level.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chou, Y-C -- Hillerich, K -- Tersoff, J -- Reuter, M C -- Dick, K A -- Ross, F M -- New York, N.Y. -- Science. 2014 Jan 17;343(6168):281-4. doi: 10.1126/science.1244623.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Functional Nanomaterials, Brookhaven National Laboratory, 735 Brookhaven Avenue, Upton, NY 11973, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24436416" target="_blank"〉PubMed〈/a〉

Description: Transmission electron microscopy offers structural and compositional information with atomic resolution, but its use is restricted to thin, solid samples. Liquid samples, particularly those involving water, have been challenging because of the need to form a thin liquid layer that is stable within the microscope vacuum. Liquid cell electron microscopy is a developing technique that allows us to apply the powerful capabilities of the electron microscope to imaging and analysis of liquid specimens. We describe its impact in materials science and biology. We discuss how its applications have expanded via improvements in equipment and experimental techniques, enabling new capabilities and stimuli for samples in liquids, and offering the potential to solve grand challenge problems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ross, Frances M -- New York, N.Y. -- Science. 2015 Dec 18;350(6267):aaa9886. doi: 10.1126/science.aaa9886. Epub 2015 Dec 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉IBM T. J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA. fmross@us.ibm.com.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26680204" target="_blank"〉PubMed〈/a〉