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1.
David Dubbeldam Sofía Calero Donald E. Ellis Randall Q. Snurr 《Molecular simulation》2016,42(2):81-101
A new software package, RASPA, for simulating adsorption and diffusion of molecules in flexible nanoporous materials is presented. The code implements the latest state-of-the-art algorithms for molecular dynamics and Monte Carlo (MC) in various ensembles including symplectic/measure-preserving integrators, Ewald summation, configurational-bias MC, continuous fractional component MC, reactive MC and Baker's minimisation. We show example applications of RASPA in computing coexistence properties, adsorption isotherms for single and multiple components, self- and collective diffusivities, reaction systems and visualisation. The software is released under the GNU General Public License. 相似文献
2.
Vanesa L. De Pietri Gerald Mayr 《Journal of Zoological Systematics and Evolutionary Research》2014,52(4):312-322
In Europe, Miocene rails (Aves, Rallidae) are quite abundant, but their phylogenetic placement in the context of recent forms has remained elusive. Rails from the early Miocene of the Saint‐Gérand‐le‐Puy area in central France were first described in the 19th century, and currently, only two species are recognized, namely Palaeoaramides christyi and Paraortygometra porzanoides. Our examination of the material however suggests the presence of four, likely coeval, species of rail from these deposits. Palaeoaramides eximius, previously synonymized with Palaeoaramides christyi, is here shown to probably be a distinct species, and a previously unrecognized rail, Baselrallus intermedius gen. et sp. nov., is described. To find out how these fossil rails are related to modern Rallidae, we compared them with an extensive sample of extant rails and identified plesiomorphic and derived features for crown group Rallidae. Our assessment does not support a particularly close relationship of either Palaeoaramides to Aramides or Paraortygometra to Crex (Ortygometra), and overall, these fossil rails are more primitive than previously assumed. Based on our observations of the morphology of the previously undescribed humerus of Palaeoaramides, we show this taxon to be outside crown group Rallidae, and perhaps closely related to the early Oligocene taxon Belgirallus. On the other hand, Paraortygometra porzanoides bears a resemblance to recent flufftails (Sarothrura spp.) in some elements, but whether it can be included in a clade together with flufftails is uncertain. 相似文献
3.
N. Billington † R. G. Danzmann P. D. N. Hebert R. D. Wards ‡ 《Journal of fish biology》1991,39(SA):251-258
Phylogenetic relationships among four Stizostedion species were examined using mitochondrial DNA (mtDNA) and allozyme analyses. Twenty-six allozyme loci were scored, and mtDNA variation was examined using 24 restriction endonucleases, yielding 48–57 restriction sites among the species. Genetic distance analyses show that the two North American species ( S. canadense and S. vitreum ) cluster in one group, while the two European species ( S. hciopercu and S. vogense ) form a second group. Nei's genetic distance between these two groups was 0.7 ± 0.2 for allozymes, while the corresponding mtDNA sequence divergence was 14.8 ± 2.0%, suggesting that these two groups diverged approximately 10 million years ago. Thus, these data are consistent with the hypothesis that Stizostedion colonized North America during the Pliocene. 相似文献
4.
Andr Barraud 《Biosensors & bioelectronics》1994,9(9-10):617-624
The Langmuir-Blodgett technique and its variants (alternate layers, self-organising mixtures, the semi-amphiphilic technique, the peculiar solid state chemistry in L.B. films) are collective methods which allow physical chemists, with a very small amount of synthetic chemistry, to build up molecular assemblies exhibiting not only the properties of each of their components, but also extra properties which arise from the architecture: cooperativity, anomalous chemical properties, molecular recognition, etc. These new tailored molecular edifices are the basic “brick” of tomorrow's molecular electronics and fine chemistry. These strategies are exemplified here by two active supramolecular edifices which have been successfully designed and built up: an artificial dioxygen trap based on the same principle as hemoglobin, and one molecule thick conductors. Promising applied results have already been obtained in the field of gas sensing with these new conductors, owing to molecular architectural amplification. 相似文献
5.
The headshield of Monospilus dispar (Cladocera, Chydoridae, Aloninae) was characterized by the presence of a unique headpore. Scanning Electron Microscopy shows the occurrence of minute pores close to the main headpore. The intimate structure of the main headpore is formed by concentric lamellae. This new information leads to new considerations about phylogeny. 相似文献
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7.
The ability of a number of nitrogen-containing compounds that simultaneously carry the adamantane and monoterpene moieties to inhibit Tdp1, an important enzyme of the DNA repair system, is studied. Inhibition of this enzyme has the potential to overcome chemotherapeutic resistance of some tumor types. Compound (+)-3c synthesized from 1-aminoadamantane and (+)-myrtenal, and compound 4a produced from 2-aminoadamantane and citronellal were found to be most potent as they inhibited Tdp1 with IC50 values of 6 and 3.5 µM, respectively. These compounds proved to have low cytotoxicity in colon HCT-116 and lung A-549 human tumor cell lines (CC50 > 50 µM). It was demonstrated that compound 4a at 10 µM enhanced cytotoxicity of topotecan, a topoisomerase 1 poison in clinical use, against HCT-116 more than fivefold and to a lesser extent of 1.5 increase in potency for A-549. 相似文献
8.
《Current biology : CB》2020,30(20):4033-4046.e8
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9.
Hisao Tsukamoto Yoshihiro Kubo David L. Farrens Mitsumasa Koyanagi Akihisa Terakita Yuji Furutani 《The Journal of biological chemistry》2015,290(45):27176-27187
Melanopsins play a key role in non-visual photoreception in mammals. Their close phylogenetic relationship to the photopigments in invertebrate visual cells suggests they have evolved to acquire molecular characteristics that are more suited for their non-visual functions. Here we set out to identify such characteristics by comparing the molecular properties of mammalian melanopsin to those of invertebrate melanopsin and visual pigment. Our data show that the Schiff base linking the chromophore retinal to the protein is more susceptive to spontaneous cleavage in mammalian melanopsins. We also find this stability is highly diversified between mammalian species, being particularly unstable for human melanopsin. Through mutagenesis analyses, we find that this diversified stability is mainly due to parallel amino acid substitutions in extracellular regions. We propose that the different stability of the retinal attachment in melanopsins may contribute to functional tuning of non-visual photoreception in mammals. 相似文献
10.