@article{879, abstract = {Having an extra copy of a gene is thought to provide some functional redundancy, which results in a higher rate of evolution in duplicated genes. In this article, we estimate the impact of gene duplication on the selection of tuf paralogs, and we find that in the absence of gene conversion, tuf paralogs have evolved significantly slower than when gene conversion has been a factor in their evolution. Thus, tuf gene copies evolve under a selective pressure that ensures their functional uniformity, and gene conversion reduces selection against amino acid substitutions that affect the function of the encoded protein, EF-Tu.}, author = {Fyodor Kondrashov and Gurbich, Tatiana A and Vlasov, Peter K}, journal = {Trends in Genetics}, number = {5}, pages = {215 -- 218}, publisher = {Elsevier}, title = {{Selection for functional uniformity of tuf duplicates in γ-proteobacteria}}, doi = {10.1016/j.tig.2007.03.002}, volume = {23}, year = {2007}, } @article{904, abstract = {Background: Independently evolving lineages mostly accumulate different changes, which leads to their gradual divergence. However, parallel accumulation of identical changes is also common, especially in traits with only a small number of possible states. Results: We characterize parallelism in evolution of coding sequences in three four-species sets of genomes of mammals, Drosophila, and yeasts. Each such set contains two independent evolutionary paths, which we call paths I and II. An amino acid replacement which occurred along path I also occurs along path II with the probability 50-8211;80% of that expected under selective neutrality. Thus, the per site rate of parallel evolution of proteins is several times higher than their average rate of evolution, but still lower than the rate of evolution of neutral sequences. This deficit may be caused by changes in the fitness landscape, leading to a replacement being possible along path I but not along path II. However, constant, weak selection assumed by the nearly neutral model of evolution appears to be a more likely explanation. Then, the average coefficient of selection associated with an amino acid replacement, in the units of the effective population size, must exceed ∼0.4, and the fraction of effectively neutral replacements must be below ∼30%. At a majority of evolvable amino acid sites, only a relatively small number of different amino acids is permitted. Conclusion: High, but below-neutral, rates of parallel amino acid replacements suggest that a majority of amino acid replacements that occur in evolution are subject to weak, but non-trivial, selection, as predicted by Ohta's nearly-neutral theory.}, author = {Bazykin, Georgii A and Fyodor Kondrashov and Brudno, Michael and Poliakov, Alexander V and Dubchak, Inna L and Kondrashov, Alexey S}, journal = {Biology Direct}, publisher = {BioMed Central}, title = {{Extensive parallelism in protein evolution}}, doi = {10.1186/1745-6150-2-20}, volume = {2}, year = {2007}, } @article{9149, abstract = {The interaction of tidal currents with sea-floor topography results in the radiation of internal gravity waves into the ocean interior. These waves are called internal tides and their dissipation due to nonlinear wave breaking and concomitant three-dimensional turbulence could play an important role in the mixing of the abyssal ocean, and hence in controlling the large-scale ocean circulation. As part of on-going work aimed at providing a theory for the vertical distribution of wave breaking over sea-floor topography, in this paper we investigate the instability of internal tides in a very simple linear model that helps us to relate the formation of unstable regions to simple features in the sea-floor topography. For two-dimensional tides over one-dimensional topography we find that the formation of overturning instabilities is closely linked to the singularities in the topography shape and that it is possible to have stable waves at the sea floor and unstable waves in the ocean interior above. For three-dimensional tides over two-dimensional topography there is in addition an effect of geometric focusing of wave energy into localized regions of high wave amplitude, and we investigate this focusing effect in simple examples. Overall, we find that the distribution of unstable wave breaking regions can be highly non-uniform even for very simple idealized topography shapes.}, author = {Bühler, Oliver and Muller, Caroline J}, issn = {0022-1120}, journal = {Journal of Fluid Mechanics}, keywords = {mechanical engineering, mechanics of materials, condensed matter physics}, pages = {1--28}, publisher = {Cambridge University Press}, title = {{Instability and focusing of internal tides in the deep ocean}}, doi = {10.1017/s0022112007007410}, volume = {588}, year = {2007}, } @article{7323, abstract = {The main factors for reducing the consumption of a vehicle are reduction of curb weight, air drag and increase in the drivetrain efficiency. Highly efficient drivetrains can be developed based on PEFC technology and curb weight may be limited by an innovative vehicle construction. In this paper, data on consumption and efficiency of a four‐place passenger vehicle with a curb weight of 850 kg and an H2/O2 fed PEFC/Supercap hybrid electric powertrain are presented. Hydrogen consumption in the New European Driving Cycle is 0.67 kg H2/100 km, which corresponds to a gasoline equivalent consumption of 2.5 l/100 km. When including the energy needed to supply pure oxygen, the calculated consumption increases from 0.67 to 0.69–0.79 kg H2/100 km, depending on the method of oxygen production.}, author = {Büchi, F. N. and Paganelli, G. and Dietrich, P. and Laurent, D. and Tsukada, A. and Varenne, P. and Delfino, A. and Kötz, R. and Freunberger, Stefan Alexander and Magne, P.-A. and Walser, D. and Olsommer, D.}, issn = {1615-6846}, journal = {Fuel Cells}, number = {4}, pages = {329--335}, publisher = {Wiley}, title = {{Consumption and efficiency of a passenger car with a Hydrogen/Oxygen PEFC based hybrid electric drivetrain}}, doi = {10.1002/fuce.200600050}, volume = {7}, year = {2007}, } @article{7324, abstract = {Efficiency is the key parameter for the application of fuel cells in automotive applications. The efficiency of a hydrogen/oxygen polymer electrolyte fuel cell system is analyzed and compared to hydrogen/air systems. The analysis is performed for the tank to electric power chain. Furthermore, the additional energy required for using pure oxygen as a second fuel is analyzed and included in the calculation. The results show that if hydrogen is produced from primary fossil energy carriers, such as natural gas and pure oxygen needs to be obtained by a conventional process; the fuel to electric current efficiency is comparable for hydrogen/oxygen and hydrogen/air systems. However, if hydrogen and oxygen are produced by the splitting of water, i.e., by electrolysis or by a thermochemical process, the fuel to electric current efficiency for the hydrogen/oxygen system is clearly superior.}, author = {Büchi, F. N. and Freunberger, Stefan Alexander and Reum, M. and Paganelli, G. and Tsukada, A. and Dietrich, P. and Delfino, A.}, issn = {1615-6846}, journal = {Fuel Cells}, number = {2}, pages = {159--164}, publisher = {Wiley}, title = {{On the efficiency of an advanced automotive fuel cell system}}, doi = {10.1002/fuce.200500257}, volume = {7}, year = {2007}, } @article{7325, abstract = {Our experimental results shown here disprove that finite diffusion can generally be assumed in ac impedance models for H2/air-polymer electrolyte fuel cells (PEFCs) to account for the diffusive transport of oxygen through the gas diffusion layer (GDL) toward the air electrode. It is shown that the amplitude of the oxygen concentration oscillation created as a consequence of superimposed ac current at the air electrode is not zero at the channel/GDL interface but extends into the gas channels, at least below modulation frequencies of fmod=10 Hz . By this, sinusoidal oxygen-concentration oscillations within the cathode gas channels are excited locally along the flow field. Due to the forced air convection in the cathode flow-field channels, a coupling via the gas phase occurs downstream of the flow field. The coupling strongly affects the local and by this the overall impedance response of the cell and evokes the formation of a low-frequency arc in H2/air-PEFC impedance spectra. Based on the experimental results, a qualitative model is presented explaining the local impedance response of a segmented 200cm2H2/air PEFC.}, author = {Schneider, I. A. and Freunberger, Stefan Alexander and Kramer, D. and Wokaun, A. and Scherer, G. G.}, issn = {0013-4651}, journal = {Journal of The Electrochemical Society}, number = {4}, publisher = {The Electrochemical Society}, title = {{Oscillations in gas channels: Part I. The forgotten player in impedance spectroscopy in PEFCs}}, doi = {10.1149/1.2435706}, volume = {154}, year = {2007}, } @article{7704, abstract = {Gradients of axon guidance molecules instruct the formation of continuous neural maps, such as the retinotopic map in the vertebrate visual system. Here we show that molecular gradients can also instruct the formation of a discrete neural map. In the fly olfactory system, axons of 50 classes of olfactory receptor neurons (ORNs) and dendrites of 50 classes of projection neurons (PNs) form one-to-one connections at discrete units called glomeruli. We provide expression, loss- and gain-of-function data to demonstrate that the levels of transmembrane Semaphorin-1a (Sema-1a), acting cell-autonomously as a receptor or part of a receptor complex, direct the dendritic targeting of PNs along the dorsolateral to ventromedial axis of the antennal lobe. Sema-1a also regulates PN axon targeting in higher olfactory centers. Thus, graded expression of Sema-1a contributes to connection specificity from ORNs to PNs and then to higher brain centers, ensuring proper representation of olfactory information in the brain.}, author = {Komiyama, Takaki and Sweeney, Lora Beatrice Jaeger and Schuldiner, Oren and Garcia, K. Christopher and Luo, Liqun}, issn = {0092-8674}, journal = {Cell}, number = {2}, pages = {399--410}, publisher = {Elsevier}, title = {{Graded expression of semaphorin-1a cell-autonomously directs dendritic targeting of olfactory projection neurons}}, doi = {10.1016/j.cell.2006.12.028}, volume = {128}, year = {2007}, } @article{7705, abstract = {Axon-axon interactions have been implicated in neural circuit assembly, but the underlying mechanisms are poorly understood. Here, we show that in the Drosophila antennal lobe, early-arriving axons of olfactory receptor neurons (ORNs) from the antenna are required for the proper targeting of late-arriving ORN axons from the maxillary palp (MP). Semaphorin-1a is required for targeting of all MP but only half of the antennal ORN classes examined. Sema-1a acts nonautonomously to control ORN axon-axon interactions, in contrast to its cell-autonomous function in olfactory projection neurons. Phenotypic and genetic interaction analyses implicate PlexinA as the Sema-1a receptor in ORN targeting. Sema-1a on antennal ORN axons is required for correct targeting of MP axons within the antennal lobe, while interactions amongst MP axons facilitate their entry into the antennal lobe. We propose that Sema-1a/PlexinA-mediated repulsion provides a mechanism by which early-arriving ORN axons constrain the target choices of late-arriving axons.}, author = {Sweeney, Lora Beatrice Jaeger and Couto, Africa and Chou, Ya-Hui and Berdnik, Daniela and Dickson, Barry J. and Luo, Liqun and Komiyama, Takaki}, issn = {0896-6273}, journal = {Neuron}, number = {2}, pages = {185--200}, publisher = {Elsevier}, title = {{Temporal target restriction of olfactory receptor neurons by semaphorin-1a/plexinA-mediated axon-axon interactions}}, doi = {10.1016/j.neuron.2006.12.022}, volume = {53}, year = {2007}, } @article{7753, abstract = {In many species, females show reduced expression of a trait that is under sexual selection in males, and this expression is thought to be maintained through genetic associations with the male phenotype. However, there is also the potential for the female trait to convey an advantage in intrasexual conflicts over resources. We tested this hypothesis in a feral population of Soay sheep, in which males and females have a polymorphism for horn development, producing either full (normal horned), reduced (scurred) or no (polled, females only) horns. During the lambing period, females who possessed horns were more likely to initiate and win aggressive interactions, independent of age, weight and birthing status. The occurrence of aggression was also context dependent, decreasing over the lambing period and associated with local density. Our results demonstrate that a trait that confers benefits to males during intrasexual competition for mates may also be used by females in intrasexual competition over resources: males use weaponry to gain mates, whereas females use weaponry to gain food.}, author = {Robinson, Matthew Richard and Kruuk, Loeske E.B}, issn = {1744-9561}, journal = {Biology Letters}, number = {6}, pages = {651--654}, publisher = {The Royal Society}, title = {{Function of weaponry in females: The use of horns in intrasexual competition for resources in female Soay sheep}}, doi = {10.1098/rsbl.2007.0278}, volume = {3}, year = {2007}, } @article{7780, abstract = {We used single-channel electrical recordings and Langevin molecular dynamics simulations to explore the electrophoretic translocation of various β-hairpin peptides across the staphylococcal α-hemolysin (αHL) protein pore at single-molecule resolution. The β-hairpin peptides, which varied in their folding properties, corresponded to the C terminal residues of the B1 domain of protein G. The translocation time was strongly dependent on the electric force and was correlated with the folding features of the β-hairpin peptides. Highly unfolded peptides entered the pore in an extended conformation, resulting in fast single-file translocation events. In contrast, the translocation of the folded β-hairpin peptides occurred more slowly. In this case, the β-hairpin peptides traversed the αHL pore in a misfolded or fully folded conformation. This study demonstrates that the interaction between a polypeptide and a β-barrel protein pore is dependent on the folding features of the polypeptide. }, author = {Goodrich, Carl Peter and Kirmizialtin, Serdal and Huyghues-Despointes, Beatrice M. and Zhu, Aiping and Scholtz, J. Martin and Makarov, Dmitrii E. and Movileanu, Liviu}, issn = {1520-6106}, journal = {The Journal of Physical Chemistry B}, number = {13}, pages = {3332--3335}, publisher = {American Chemical Society}, title = {{Single-molecule electrophoresis of β-hairpin peptides by electrical recordings and Langevin dynamics simulations}}, doi = {10.1021/jp071364h}, volume = {111}, year = {2007}, } @article{7781, abstract = {Males are predicted to compete for reproductive opportunities, with sexual selection driving the evolution of large body size and weaponry through the advantage they confer for access to females. Few studies have explored potential trade‐offs of investment in secondary sexual traits between different components of fitness or tested for sexually antagonistic selection pressures. These factors may provide explanations for observed polymorphisms in both form and quality of secondary sexual traits. We report here an analysis of selection on horn phenotype in a feral population of Soay sheep (Ovis aries) on the island of Hirta, St. Kilda, Scotland. Soay sheep display a phenotypic polymorphism for horn type with males growing either normal or reduced (scurred) horns, and females growing either normal, scurred, or no (polled) horns; further variation in size exists within horn morphs. We show that horn phenotype and the size of the trait displayed is subject to different selection pressures in males and females, generating sexually antagonistic selection. Furthermore, there was evidence of a trade‐off between breeding success and longevity in normal‐horned males, with both the normal horn type and larger horn size being associated with greater annual breeding success but reduced longevity. Therefore, selection through lifetime breeding success was not found to act upon horn phenotype in males. In females, a negative association of annual breeding success within the normal‐horned phenotype did not result in a significant difference in lifetime fitness when compared to scurred individuals, as no significant difference in longevity was found. However, increased horn size within this group was negatively associated with breeding success and longevity. Females without horns (polled) suffered reduced longevity and thus reduced lifetime breeding success relative the other horn morphs. Our results therefore suggest that trade‐offs between different components of fitness and antagonistic selection between the sexes may maintain genetic variation for secondary sexual traits within a population.}, author = {Robinson, Matthew Richard and Pilkington, Jill G. and Clutton-Brock, Tim H. and Pemberton, Josephine M. and Kruuk, Loeske E.B.}, issn = {0014-3820}, journal = {Evolution}, number = {10}, pages = {2168--2181}, publisher = {Wiley}, title = {{Live fast, die young: Trade-offs between fitness components and sexually antagonistic selection on weaponry in soay sheep}}, doi = {10.1111/j.0014-3820.2006.tb01854.x}, volume = {60}, year = {2007}, } @article{8027, abstract = {Gating deficits and hallucinatory sensations are prominent symptoms of schizophrenia. Comparing these abnormalities with the failure modes of network models is an interesting way to explore how they arise. We present a network model that can both propagate and gate signals. The model exhibits effects reminiscent of clinically observed pathologies when the balance between excitation and inhibition that it requires is not properly maintained.}, author = {Vogels, Tim P and Abbott, L.}, issn = {0176-3679}, journal = {Pharmacopsychiatry}, number = {S 1}, pages = {S73--S77}, publisher = {Thieme}, title = {{Gating deficits in model networks: A path to schizophrenia?}}, doi = {10.1055/s-2007-992130}, volume = {40}, year = {2007}, } @inbook{167, abstract = {This book contains research articles on Diophantine Geometry, written by participants of a research program held at the Ennio De Giorgi Mathematical Research Center in Pisa, Italy, during the period April – July 2005. The authors are eminent experts in the field. Several subfields of the main topic are presented; the volume thus is particularly useful to get a broad overview of recent research developments.}, author = {Browning, Timothy D and Heath Brown, Roger}, booktitle = {Diophantine Geometry}, editor = {Zannier, Umberto}, pages = {93 -- 100}, publisher = {Edizioni della Normale}, title = {{Simultaneous equal sums of three powers}}, volume = {4}, year = {2007}, } @article{1750, abstract = {The authors investigate the composition profile of SiGe islands after capping with Si to form quantum dots, using a two step etching procedure and atomic force microscopy. Initially, the Si capping layers are removed by etching selectively Si over Ge and then the composition of the disclosed islands is addressed by selectively etching Ge over Si. For samples grown at 580 °C the authors show that even when overgrowth leads to a flat Si surface and the islands undergo strong morphological changes, a Ge-rich core region is still preserved in the dot. At high growth and overgrowth temperatures (740 °C), the experiments show that the newly formed base of the buried islands is more Si rich than their top. Furthermore, the authors find that for the growth conditions used, no lateral motion takes place during capping.}, author = {Georgios Katsaros and Stoffel, Mathieu and Rastelli, Armando and Schmidt, Oliver G and Kern, Klaus and Tersoff, Jerry}, journal = {Applied Physics Letters}, number = {1}, publisher = {American Institute of Physics}, title = {{Three-dimensional isocompositional profiles of buried SiGeSi (001) islands}}, doi = {10.1063/1.2752730}, volume = {91}, year = {2007}, } @article{1762, abstract = {In quantum information science, the phase of a wave function plays an important role in encoding information. Although most experiments in this field rely on dynamic effects to manipulate this information, an alternative approach is to use geometric phase, which has been argued to have potential fault tolerance. We demonstrated the controlled accumulation of a geometric phase, Berry's phase, in a superconducting qubit; we manipulated the qubit geometrically by means of microwave radiation and observed the accumulated phase in an interference experiment. We found excellent agreement with Berry's predictions and also observed a geometry-dependent contribution to dephasing.}, author = {Leek, Peter J and Johannes Fink and Blais, Alexandre and Bianchetti, R and Göppl, M and Gambetta, Jay M and Schuster, David I and Frunzio, Luigi and Schoelkopf, Robert J and Wallraff, Andreas}, journal = {Science}, number = {5858}, pages = {1889 -- 1892}, publisher = {American Association for the Advancement of Science}, title = {{Observation of Berry's phase in a solid-state qubit}}, doi = {10.1126/science.1149858}, volume = {318}, year = {2007}, } @article{1797, abstract = {Intrinsically photosensitive melanopsin-containing retinal ganglion cells (ipRGCs) control important physiological processes, including the circadian rhythm, the pupillary reflex, and the suppression of locomotor behavior (reviewed in [1]). ipRGCs are also activated by classical photoreceptors, the rods and cones, through local retinal circuits [2, 3]. ipRGCs can be transsynaptically labeled through the pupillary-reflex circuit with the derivatives of the Bartha strain of the alphaherpesvirus pseudorabies virus(PRV) [4, 5] that express GFP [6-12]. Bartha-strain derivatives spread only in the retrograde direction [13]. There is evidence that infected cells function normally for a while during GFP expression [7]. Here we combine transsynaptic PRV labeling, two-photon laser microscopy, and electrophysiological techniques to trace the local circuit of different ipRGC subtypes in the mouse retina and record light-evoked activity from the transsynaptically labeled ganglion cells. First, we show that ipRGCs are connected by monostratified amacrine cells that provide strong inhibition from classical-photoreceptor-driven circuits. Second, we show evidence that dopaminergic interplexiform cells are synaptically connected to ipRGCs. The latter finding provides a circuitry link between light-dark adaptation and ipRGC function.}, author = {Viney, Tim J and Bálint, Kamill and Hillier, Dániel and Sandra Siegert and Boldogköi, Zsolt S and Enquist, Lynn W and Meister, Markus and Cepko, Constance L and Roska, Botond M}, journal = {Current Biology}, number = {11}, pages = {981 -- 988}, publisher = {Cell Press}, title = {{Local retinal circuits of melanopsin-containing ganglion cells identified by transsynaptic viral tracing}}, doi = {10.1016/j.cub.2007.04.058}, volume = {17}, year = {2007}, } @article{1964, abstract = {Complex I of respiratory chains plays a central role in cellular energy production. Mutations in its subunits lead to many human neurodegenerative diseases. Recently, a first atomic structure of the hydrophilic domain of complex I from Thermus thermophilus was determined. This domain represents a catalytic core of the enzyme. It consists of eight different subunits, contains all the redox centers, and comprises more than half of the entire complex. In this review, novel mechanistic implications of the structure are discussed, and the effects of many known mutations of complex I subunits are interpreted in a structural context.}, author = {Leonid Sazanov}, journal = {Biochemistry}, number = {9}, pages = {2275 -- 2288}, publisher = {ACS}, title = {{Respiratory complex I: Mechanistic and structural insights provided by the crystal structure of the hydrophilic domain}}, doi = {10.1021/bi602508x}, volume = {46}, year = {2007}, } @article{1965, abstract = {Respiratory complex I (NADH:ubiquinone oxidoreductase) is an L-shaped multisubunit protein assembly consisting of a hydrophobic membrane arm and a hydrophilic peripheral arm. It catalyses the transfer of two electrons from NADH to quinone coupled to the translocation of four protons across the membrane. Although we have solved recently the crystal structure of the peripheral arm, the structure of the complete enzyme and the coupling mechanism are not yet known. The membrane domain of Escherichia coli complex I consists of seven different subunits with total molecular mass of 258 kDa. It is significantly more stable than the whole enzyme, which allowed us to obtain well-ordered two-dimensional crystals of the domain, belonging to the space group p22121. Comparison of the projection map of negatively stained crystals with previously published low-resolution structures indicated that the characteristic curved shape of the membrane domain is remarkably well conserved between bacterial and mitochondrial enzymes, helping us to interpret projection maps in the context of the intact complex. Two pronounced stain-excluding densities at the distal end of the membrane domain are likely to represent the two large antiporter-like subunits NuoL and NuoM. Cryo-electron microscopy on frozen-hydrated crystals allowed us to calculate a projection map at 8 Å resolution. About 60 transmembrane α-helices, both perpendicular to the membrane plane and tilted, are present within one membrane domain, which is consistent with secondary structure predictions. A possible binding site and access channel for quinone are found at the interface with the peripheral arm. Tentative assignment of individual subunits to the features of the map has been made. The location of subunits NuoL and NuoM at substantial distance from the peripheral arm, which contains all the redox centres of the complex, indicates that conformational changes are likely to play a role in the mechanism of coupling between electron transfer and proton pumping.}, author = {Baranova, Ekaterina A and Holt, Peter J and Leonid Sazanov}, journal = {Journal of Molecular Biology}, number = {1}, pages = {140 -- 154}, publisher = {Elsevier}, title = {{Projection structure of the membrane domain of Escherichia coli respiratory Complex I at 8 Å resolution}}, doi = {10.1016/j.jmb.2006.11.026}, volume = {366}, year = {2007}, } @article{1969, abstract = {Respiratory complex I catalyses the transfer of electrons from NADH to quinone coupled to the translocation of protons across the membrane. The mechanism of coupling and the structure of the complete enzyme are not known. The membrane domain of the complex contains three similar antiporter-like subunits NuoL/M/N, probably involved in proton pumping. We have previously shown that subunits NuoL/M can be removed from the rest of the complex, suggesting their location at the distal end of the membrane domain. Here, using electron microscopy and single particle analysis, we show that subunits NuoL and M jointly occupy a distal half of the membrane domain, separated by about 10 nm from the interface with the peripheral arm. This indicates that coupling mechanism of complex I is likely to involve long range conformational changes.}, author = {Baranova, Ekaterina A and Morgan, David J and Leonid Sazanov}, journal = {Journal of Structural Biology}, number = {2 SPEC. ISS.}, pages = {238 -- 242}, publisher = {Academic Press}, title = {{Single particle analysis confirms distal location of subunits NuoL and NuoM in Escherichia coli complex I}}, doi = {10.1016/j.jsb.2007.01.009}, volume = {159}, year = {2007}, } @article{13424, abstract = {Changing shapes: Metastable spherical aggregates of gold nanoparticles undergo a one-to-one, thermally induced transformation into heterodimers comprising connected plate and spherical domains. By controlling the reaction time, it is possible to isolate a variety of structures differing in the relative sizes of the domains and in the overall optical properties (see picture).}, author = {Klajn, Rafal and Pinchuk, Anatoliy O. and Schatz, George C. and Grzybowski, Bartosz A.}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, keywords = {General Chemistry, Catalysis}, number = {44}, pages = {8363--8367}, publisher = {Wiley}, title = {{Synthesis of heterodimeric sphere–prism nanostructures via metastable gold supraspheres}}, doi = {10.1002/anie.200702570}, volume = {46}, year = {2007}, }