Tris(4,4′-di-tert-butyl-2,2′-bipyridine-κ2 N,N′)molybdenum(II) μ6-oxido-dodeca-μ2-oxido-hexa­oxidohexa­molybdate(VI) acetonitrile tetra­solvate

The asymmetric unit of the title compound, [Mo(C18H24N2)3][Mo6O19]·4CH3CN, comprises an [Mo(di-t-Bu-bipy)3]2+ cation (di-t-Bu-bipy is 4,4′-di-tert-butyl-2,2′-bipyridine), two halves of Lindqvist-type [Mo6O19]2− anions (with each anion completed by the application of a center of inversion) and four acetonitrile solvent mol­ecules. The geometry around the metal atom of the cation resembles a distorted octa­hedron, with each of the three di-t-Bu-bipy ligands being almost planar [deviation from planarity < 6.3 (2)°]. Supra­molecular inter­actions, namely Mo=O⋯π, C N⋯π, C—H⋯O and C—H⋯N, along with electrostatic forces, mediate the crystal packing. Two of the tert-butyl groups are affected by rotational disorder which was modeled over two distinct positions with major site occupancies of 0.707 (9) and 0.769 (8)

Propyl­ammonium 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dionate

The title salt, C3H10N+·C14H8F3O2 −, constitutes the first organic crystal containing a residue of 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dione. The terminal –CF3 group is disordered over two locations [occupancy ratio = 0.830 (7):0.170 (7)]. Bond delocalization involving the two carbonyl groups and the α-carbon was observed. The crystal packing is mediated by several supra­molecular inter­actions, namely charged-assisted N—H⋯O hydrogen bonds, C—H⋯F and C—F⋯F short contacts and C—H⋯π inter­actions

RF CMOS Wireless Implantable Microsystem for Sacral Roots Stimulation with On-Chip Antenna and Far-Field Wireless Powering

The use of heterogeneous integration technologies is the path for the development of further miniaturized, smarter, and energy autonomous microdevices, which are required to tackle the challenge of monitoring and/or control the health condition of everyone, everywhere. The interaction with human body requires the use of flexible materials, while the electronic component are based on rigid materials, like silicon substrates. Also, once inside the human body, it is desirable to have a wireless link for data communication, as well for RF powering, using energy harvesting techniques or dedicated powering RF links. This paper shows the design of an implantable microsystem to be used for functional electrical stimulation of sacral roots. The proposed system includes flexible electrodes, integrated with an RF CMOS chip, which is powered by a wireless link through an efficient on-chip antenna.This work was supported by the Portuguese Foundation for Science and Technology (SFRH/BD/62608/2009), FCT-PTDC/EEI-TEL/2881/2012, Programa Operacional Temático Fatores de Competitividade (COMPETE) and Fundo Comunitário Europeu FEDER.info:eu-repo/semantics/publishedVersio

μ-Oxido-bis­[chlorido(4,4′-di-tert-butyl-2,2′-bipyridine-κ2 N,N′)dioxido­molybdenum(VI)] 0.2-hydrate

The title hydrate, [Mo2Cl2O5(C18H24N2)2]·0.2H2O, has been isolated as the oxidation product of [Mo(η3-C3H5)Cl(CO)2(di-t-Bu-bipy)] (where di-t-Bu-bipy is 4,4′-di-tert-butyl-2,2′-bipyridine). A μ-oxide ligand bridges two similar MoCl(di-t-Bu-bipy)O2 units, having the terminal oxide ligands mutually cis, and the chloride and μ-oxide trans to each other. In the binuclear complex, the coordination geometries of the metal atoms can be described as highly distorted octa­hedra. Individual complexes co-crystallize with a partially occupied water mol­ecule of crystallization (occupancy factor = 0.20; H atoms not located), with the crystal packing being mediated by the need to effectively fill the available space. A number of weak C—H⋯O and C—H⋯Cl inter­actions are present

(2,2′-Bipyridine-κ2 N,N′)bromido(1,4,7-trithia­cyclo­nonane-κ3 S,S′,S′′)ruthenium(II) hexa­fluoridophosphate

The title compound, [RuBr(C10H8N2)(C6H12S3)]PF6 or [RuBr(bpy)([9]aneS3)]PF6 ([9]aneS3 is 1,4,7-trithia­cyclo­nonane and bpy is 2,2′-bipyridine), exhibits a very similar octahedral coordination geometry for the Ru2+ atom to that of its [RuCl(bpy)([9]aneS3)]+ analogue, with only the chloride ligand being substituted by a bromide ligand. The presence of a PF6 − anion (alongside with the coordinated bromide ligand) promotes the existence of an extensive network of weak C—H⋯X (X = F, Br) inter­actions

Cooperation or conflict? Impact of intraspecific diversity on Escherichia coli biofilms

Intraspecific diversity in biofilm communities is associated with enhanced survival and growth of the individual biofilm populations. In here, we assess if this apparent cooperative behavior still holds as the number of different strains in a biofilm increases. Using E. coli as a model organism, the influence of intraspecific diversity in biofilm populations composed of up to six different E. coli strains, was assessed. Biofilm quantification was evaluated by crystal violet (CV) staining and colony forming units (CFU) counts. In general, with the increasing number of strains in a biofilm, an increase in cell counts and a decrease in matrix production was observed. This observation was confirmed by cluster analysis that indicated that after 24h of biofilm formation the best model, according to the Bayesian information criterion (BIC), consisted of three clusters that grouped together biofilms with an equal number of strains. It hence appears that increased genotypic diversity in a biofilm leads E. coli to maximize the production of its offspring, in detriment of the production of public goods (i.e. matrix components), that would be beneficial to all strains individually and the consortium as a whole. Apart from the ecological implications, these results can be explored in the area of clinical biofilms, as a decrease in matrix production might render these intraspecies biofilms more sensitive to antimicrobial agents

Mechanical activation of pre-alloyed NiTi2 and elemental Ni for the synthesis of NiTi alloys

ABSTRACT: This work reports on an efficient powder metallurgy method for the synthesis of NiTi alloys, involving mechanical activation of pre-alloyed NiTi2 and elemental Ni powders (NiTi2-Ni) followed by a press-and-sinter step. The idea is to take advantage of the brittle nature of NiTi2 to promote a better efficiency of the mechanical activation process. The conventional mechanical activation route using elemental Ti and Ni powders (Ti-Ni) was also used for comparative purposes. Starting with (NiTi2-Ni) powder mixtures resulted in the formation of a predominant amorphous structure after mechanical activation at 300 rpm for 2 h. A sintered specimen consisting mainly of NiTi phase was obtained after vacuum sintering at 1050 degrees C for 0.5 h. The produced NiTi phase exhibited the martensitic transformation behavior. Using elemental Ti powders instead of pre-alloyed NiTi2 powders, the structural homogenization of the synthesized NiTi alloys was delayed. Performing the mechanical activation at 300 rpm for the (Ti-Ni) powder mixtures gave rise to the formation of composite particles consisting in dense areas of alternate fine layers of Ni and Ti. However, no significant structural modification was observed even after 16 h of mechanical activation. Only after vacuum sintering at 1050 degrees C for 6 h, the NiTi phase was observed to be the predominant phase. The higher reactivity of the mechanically activated (NiTi2-Ni) powder particles can explain the different sintering behavior of those powders compared with the mechanically activated (Ti-Ni) powders. It is demonstrated that this innovative approach allows an effective time reduction in the mechanical activation and of the vacuum sintering step.info:eu-repo/semantics/publishedVersio

Neotectónica e períodos de recorrência de grandes sismos e tsunamis na margem SW Ibérica e Golfo de Cádis

Neste trabalho usámos o método numérico das placas finas (Bird, 1999) para modelar a Neotectónica no Golfo de Cadiz e estimar os períodos de recorrência de grandes sismos e tsunamis. Foram testadas várias configurações de falhas e condições fronteira, e os resultados comparados com as observações de GPS, tensão e deformação sísmica. O melhor ajuste às observações é obtido com um modelo que apresenta uma taxa de movimentação de 1 mm/a nos cavalgamentos com orientação E-O e NE-SO, o que corresponde a períodos de recorrência de 1150, 3620 e 9900 anos para sismos de magnitude Mw de 7, 8 e 8.75

2-Amino-6-[(2,6-dichloro­phen­yl)imino]-3-oxocyclo­hexa-1,4-dienecarbaldehyde

The title compound, C13H8Cl2N2O2, was obtained by the oxidation of diclofenac {systematic name: 2-[2-(2,6-dichloro­phenyl­amino)­phen­yl]acetic acid}, an anti-inflammatory drug, with hydrogen peroxide catalysed by chlorido[5,10,15,20-tetra­kis­(2,6-dichloro­phen­yl)porphyrinato]manganese(III), using ammonium acetate as co-catalyst. The asymmetric unit contains two crystallographically independent mol­ecules of the title compound (Z′ = 2). The close packing of individual mol­ecules is mediated by a series of strong and rather directional N—H⋯Cl and N—H⋯O hydrogen bonds, plus weak π–π [distance between the individual double bonds of symmetry-related imino­quinone rings = 3.7604 (13) Å] and Cl⋯O inter­actions [3.0287 (18) Å]