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The p53 tumor suppressor is widely found to be mutated in human cancer. This protein is regarded as a molecular hub regulating different cell responses, namely cell death. Compelling data have demonstrated that the impairment of p53 activity correlates with tumor development and maintenance. For these reasons, the reactivation of p53 function is regarded as a promising strategy to halt cancer. In the present work, the recombinant mutant p53R280K DNA binding domain (DBD) was produced for the first time, and its crystal structure was determined in the absence of DNA to a resolution of 2.0 Å. The solved structure contains four molecules in the asymmetric unit, four zinc(II) ions, and 336 water molecules. The structure was compared with the wild-type p53 DBD structure, isolated and in complex with DNA. These comparisons contributed to a deeper understanding of the mutant p53R280K structure, as well as the loss of DNA binding related to halted transcriptional activity. The structural information derived may also contribute to the rational design of mutant p53 reactivating molecules with potential application in cancer treatment.

The adhesively bonded joints behaviour under cyclic loading is not yet well understood due to its inherent complexity. Numerical approaches appear, therefore, as the easiest way to simulate such mechanical behaviour. In this work, double strap bonded joints with Carbon Fibres Reinforced Polymers (CFRP) and aluminium are numerically simulated and subjected to a cyclic loading history. In the numerical simulation, the Distinct Element Method (DEM) is used and it is assumed cohesive bi-linear bond-slip models with local damage of the interface. The evaluation of the bonded joints under cyclic loading is made by comparing the results with those simulated with a monotonic loading.

A procura de soluções de reforço mais duráveis e de fácil aplicação tem levado à utilização crescente dos compósitos de FRP (Fiber Reinforced Polymer) no reforço de estruturas, dada a sua resistência à corrosão, o baixo quociente peso/resistência mecânica, a sua moldabilidade, a facilidade de aplicação e a eliminação de estruturas de suporte. No reforço estrutural de vigas de betão armado com compósitos de FRP, são tradicionalmente utilizados dois tipos de técnicas: os sistemas em que o laminado é colado pelo exterior (EBR - Externally-Bonded Reinforcement) ou aqueles em que o laminado é inserido em rasgos previamente abertos na camada de recobrimento (NSM - Near Surface Mounted). No entanto, as técnicas utilizadas, o comportamento elástico-linear destes materiais e as roturas tendencialmente frágeis das soluções condicionam a sua utilização em estruturas onde se pretende alguma ductilidade. A técnica de reforço NSM apresenta algumas vantagens em relação à técnica EBR, nomeadamente ao nível da proteção das armaduras [1]. Além disso, o desempenho em termos de ductilidade do sistema e resistência final excede a técnica EBR. Contudo, diversos ensaios experimentais [2-5] têm mostrado que roturas prematuras [6] da ligação na interface ou o destacamento do betão na zona do recobrimento entre a face inferior das armaduras ordinárias e as armaduras de reforço podem limitar significativamente a eficiência do sistema, originando modos de rotura frágeis e desperdício de material por falta de otimização da quantidade de material aplicado [1]. A fim de evitar a rotura prematura das soluções de reforço tradicionais (EBR e NSM), foi concebido na Universidade NOVA um sistema inovador de reforço intitulado CREatE (Continuous Reinforcement Embedded at Ends). O sistema CREatE foi idealizado para ser utilizado com diversos materiais [1, 5] e diferentes elementos estruturais, tais como vigas [1, 3], pilares [7], pavimentos [8], lajes ou paredes, em que é necessário aumentar a sua capacidade resistente através de armaduras pós-instaladas. A solução de reforço CREatE caracteriza-se pela utilização de armaduras contínuas embutidas nas extremidades do elemento estrutural sem o uso de dispositivos mecânicos para as fixar. Antes da ancoragem da armadura de reforço no interior do elemento, é necessário utilizar uma curva de transição suave para al terar a forma da armadura de reforço e evitar a concentração de tensões no la minado de CFRP (Carbon Fiber Reinforced Polymer) ou na interface e, desta forma, ter um fluxo gradual de tensões transmitidas à zona de ancoragem existente no interior do elemento. Para validar a solução CREatE foi realizada uma campanha de ensaios à flexão de vigas de betão armado com seção em T, uma altura total de 0,3m, um vão livre de 3,0m e reforçadas com laminados de CFRP recorrendo a diferentes técnicas (EBR, NSM e CREatE). As vigas foram testadas à flexão em 4 pontos, tendo-se obtido resultados promissores (Figura 1), com a eliminação na técnica CREatE dos modos de rotura prematuros. Na Figura 2 é possível observar uma viga ensaiada com a técnica CREatE em que se detetam aberturas de fendas significativas sem que se verifique qualquer rotura prematura do sistema. Além da eliminação dos modos de rotura prematuros, os ensaios comprovam que a técnica CREatE permite o incremento da ductilidade (Figura 1) e a exploração total da capacidade do CFRP [1, 3, 5].

The Spheroolithidae oospecies Guegoolithus turolensis, putatively attributed to non-hadrosauroid styracosterns was first described in the Barremian of the Iberian Basin, and later reported in the Valanginian–Hauterivian of the Cameros Basin, with both occurrences separated by a few hundred kilometres but by over 10 million years.

ABSTRACTCyclotosaurus naraserluki, sp. nov., is a new Late Triassic capitosaurid amphibian from lacustrine deposits in the Fleming Fjord Formation of the Jameson Land Basin in Greenland. It is based on a fairly complete and well-preserved skull associated with two vertebral intercentra. Previously reported as Cyclotosaurus cf. posthumus, C. naraserluki is unique among cyclotosaurs for having the postorbitals embaying the supratemporals posteromedially. The anterior palatal vacuity presents an autapomorphic complete subdivision by a wide medial premaxillary-vomerine bony connection. The parasphenoid projects between the pterygoids and the exoccipitals, preventing a suture between the two, a primitive condition shared with Rhinesuchidae, Eryosuchus, and Kupferzellia. Within Cyclotosaurus, the Greenlandic skull has a distinctive combination of circular choanae (shared with C. ebrachensis, C. posthumus, and C. robustus) and a convex posteromedial margin of the tabulars (also present in C. ebrachensis and C. intermedius). A phylogenetic analysis indicates that C. naraserluki is the sister taxon of the middle Norian C. mordax from southern Germany, with which it shares a pair of premaxillary foramina. Cyclotosaurus is one of the most successful and diverse genera of Late Triassic temnospondyls, with at least eight species reported from middle Carnian to late Norian. Cyclotosaurus naraserluki is the largest amphibian ever reported from Greenland and one of the Late Triassic vertebrates with the highest northern paleolatitude currently known.http://zoobank.org/urn:lsid:zoobank.org:pub:43AAA541-031C-4EE1-B819-4846EBBD1BBBSUPPLEMENTAL DATA?Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Marzola, M., O. Mateus, N. H. Shubin, and L. B. Clemmensen. 2017. Cyclotosaurus naraserluki, sp. nov., a new Late Triassic cyclotosaurid (Amphibia, Temnospondyli) from the Fleming Fjord Formation of the Jameson Land Basin (East Greenland). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1303501.ABSTRACTCyclotosaurus naraserluki, sp. nov., is a new Late Triassic capitosaurid amphibian from lacustrine deposits in the Fleming Fjord Formation of the Jameson Land Basin in Greenland. It is based on a fairly complete and well-preserved skull associated with two vertebral intercentra. Previously reported as Cyclotosaurus cf. posthumus, C. naraserluki is unique among cyclotosaurs for having the postorbitals embaying the supratemporals posteromedially. The anterior palatal vacuity presents an autapomorphic complete subdivision by a wide medial premaxillary-vomerine bony connection. The parasphenoid projects between the pterygoids and the exoccipitals, preventing a suture between the two, a primitive condition shared with Rhinesuchidae, Eryosuchus, and Kupferzellia. Within Cyclotosaurus, the Greenlandic skull has a distinctive combination of circular choanae (shared with C. ebrachensis, C. posthumus, and C. robustus) and a convex posteromedial margin of the tabulars (also present in C. ebrachensis and C. intermedius). A phylogenetic analysis indicates that C. naraserluki is the sister taxon of the middle Norian C. mordax from southern Germany, with which it shares a pair of premaxillary foramina. Cyclotosaurus is one of the most successful and diverse genera of Late Triassic temnospondyls, with at least eight species reported from middle Carnian to late Norian. Cyclotosaurus naraserluki is the largest amphibian ever reported from Greenland and one of the Late Triassic vertebrates with the highest northern paleolatitude currently known.http://zoobank.org/urn:lsid:zoobank.org:pub:43AAA541-031C-4EE1-B819-4846EBBD1BBBSUPPLEMENTAL DATA?Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Marzola, M., O. Mateus, N. H. Shubin, and L. B. Clemmensen. 2017. Cyclotosaurus naraserluki, sp. nov., a new Late Triassic cyclotosaurid (Amphibia, Temnospondyli) from the Fleming Fjord Formation of the Jameson Land Basin (East Greenland). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1303501.

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The cyclic shift graph of a monoid is the graph whose vertices are elements of the monoid and whose edges link elements that differ by a cyclic shift. For certain monoids connected with combinatorics, such as the plactic monoid (the monoid of Young tableaux) and the sylvester monoid (the monoid of binary search trees), connected components consist of elements that have the same evaluation (that is, contain the same number of each generating symbol). This paper discusses new results on the diameters of connected components of the cyclic shift graphs of the finite-rank analogues of these monoids, showing that the maximum diameter of a connected component is dependent only on the rank. The proof techniques are explained in the case of the sylvester monoid.

Glass samples with a molar composition (64+x)ZnO-(16-x)B2O3-20SiO2, where x=0 or 1, were successfully synthesized using a melt-quenching technique. Based on differential thermal analysis data, the produced glass samples were submitted to controlled heat-treatments at selected temperatures (610, 615 and 620{\{}$\backslash$textdegree{\}}C) during various times ranging from 8 to 30h. The crystallization of willemite (Zn2SiO4) within the glass matrix was confirmed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Under specific heat-treatment conditions, transparent nanocomposite glass-ceramics were obtained, as confirmed by UV-vis spectroscopy. The influence of temperature, holding time and glass composition on crystal growth was investigated. The mean crystallite size was determined by image analysis on SEM micrographs. The results indicated an increase on the crystallite size and density with time and temperature. The change of crystallite size with time for the heat-treatments at 615 and 620{\{}$\backslash$textdegree{\}}C depended on the glass composition. Under fixed heat-treatment conditions, the crystallite density was comparatively higher for the glass composition with higher ZnO content. {\{}©{\}} 2016.

Crystal graphs, in the sense of Kashiwara, carry a natural monoid structure given by identifying words labelling vertices that appear in the same position of isomorphic components of the crystal. In the particular case of the crystal graph for the q-analogue of the special linear Lie algebra sln, this monoid is the celebrated plactic monoid, whose elements can be identified with Young tableaux. The crystal graph and the so-called Kashiwara operators interact beautifully with the combinatorics of Young tableaux and with the Robinson--Schensted correspondence and so provide powerful combinatorial tools to work with them. This paper constructs an analogous `quasi-crystal' structure for the hypoplactic monoid, whose elements can be identified with quasi-ribbon tableaux and whose connection with the theory of quasi-symmetric functions echoes the connection of the plactic monoid with the theory of symmetric functions. This quasi-crystal structure and the associated quasi-Kashiwara operators are shown to interact just as neatly with the combinatorics of quasi-ribbon tableaux and with the hypoplactic version of the Robinson--Schensted correspondence. A study is then made of the interaction of the crystal graph of the plactic monoid and the quasi-crystal graph for the hypoplactic monoid. Finally, the quasi-crystal structure is applied to prove some new results about the hypoplactic monoid.

The electron transfer pathways for the enzymes involved in the four sequential steps of the denitrification pathway are reviewed. In addition, brief information on the electron transfer events is also provided on two enzymes that participate in the dissimilatory nitrate reduction to ammonia. The two main aspects discussed are the intra- and inter-molecular electron transfer pathways and the molecular recognition processes involving the redox partners. When available, information on the residues that are involved in these pathways is given, and their role in electron transfer and/or the formation of the transient electron transfer complexes is discussed. © The Royal Society of Chemistry 2017.

This book is devoted to denitrification, an anaerobic process that is used by a wide range of bacteria for energy generation. The overall process involves nitrate, which is present in soil or water, being reduced to gaseous dinitrogen. This initial chapter aims to place denitrification in the larger context of the nitrogen biogeochemical cycle (a bird's eye view). Detailed topics are developed through the many following contributions. Denitrification is a landscape for probing the structures, functions and mechanisms of action of a wide range of highly specialised metalloenzymes. These carry out, sequentially, four oxo-transfer reactions: NO3 - → NO2 - → NO → N2O → N2. The environmental implications of these processes are of particular relevance. Nitrate accumulation and the release of nitrous oxide into the atmosphere due to the excessive use of fertilisers in agriculture are examples of two environmental problems in which denitrification plays a central role. © The Royal Society of Chemistry 2017.

Nitrous oxide reductase is the enzyme that catalyses the last step of the denitrification pathway, reducing nitrous oxide to dinitrogen gas. This enzyme is a functional homodimer with two copper centres, CuA and a "CuZ centre", located in different domains. The CuA centre is the electron transferring centre, while the catalytic centre is the "CuZ centre", a unique metal centre in biology - a tetranuclear copper centre with a μ4-bridging sulphide. The enzyme has been isolated with the "CuZ centre" in two different forms, CuZ(4Cu2S) and CuZ∗(4Cu1S), with the first presenting an additional μ2-sulphur atom as a bridging ligand between CuI and CuIV of the "CuZ centre", whereas the second form was identified as a water-derived molecule. Spectroscopic analysis of CuZ∗(4Cu1S), together with computational studies, indicated that there is a hydroxide bound to CuI. Genomic analysis has identified the presence of two different types of nitrous oxide reductase, the typical and "atypical", with a single member of the last group having been isolated to date, from Wolinella succinogenes. Thus, here the structure of the "typical" nitrous oxide reductase with either CuZ(4Cu2S) or CuZ∗(4Cu1S), as well as its spectroscopic and catalytic properties, will be discussed. © The Royal Society of Chemistry 2017.