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Shape morphing materials, especially those fabricated by 4D printing, are gaining much attention due to their versatility of actuation and capability of being programmed in advance. These materials become particularly interesting for biomedical applications where implant materials could be remotely actuated, exerting a force on the surrounding tissues and cells. However, applications in this field have been restricted due to the biocompatibility of the materials and the character of the required stimuli, generally not compatible with physiological environments. Magnetic nanoparticles (MNPs) represent a great opportunity to this end; however, the actuation results in a uniform movement toward the magnet that requires anchoring of the object. Here, for the first time, the application of anisotropic Fe3O4 MNPs is described, and synthesized by a novel and easy route, that can be aligned on pre-defined patterns within objects printed by digital light processing, resulting in materials that can be actuated remotely (4D printing). These nanoparticles (178 nm x 55 nm), show good biocompatibility when directly seeded on top of human mesenchymal stem cells, despite being uptaken. Most importantly, the alignment of the MNPs can tune the movement of fabricated nanocomposite materials, resulting in complex movements of attraction or repulsion depending on the direction of the applied magnetic field. T.K., and S.C.-E. contributed equally to this work. This work was supported financially by the Province of Limburg and the Brightlands Materials Center. The authors were also grateful to the research program Innovation Fund Chemistry, which was partly financed by the Netherlands Organization for Scientific Research (NWO) under TA grant agreement 731.016.202 ("DynAM"). The authors acknowledge the Texas A&M Health Science Center College of Medicine Institute for Regenerative Medicine at Scott & White who isolated and provided the cells through a grant from NCRR of the NIH (Grant #P40RR017447).

Antimicrobial-peptide-based therapies could represent a reliable alternative to overcome antibiotic resistance, as they offer potential advantages such as rapid microbicidal activity and multiple activities against a broad spectrum of bacterial pathogens. Three synthetic antimicrobial peptides (AMPs), AMP72, AMP126, and also AMP2041, designed by using ad hoc screening software developed in house, were synthesized and tested against nine reference strains. The peptides showed a partial β-sheet structure in 10-mM phosphate buffer. Low cytolytic activity towards both human cell lines (epithelial, endothelial, and fibroblast) and sheep erythrocytes was observed for all peptides. The antimicrobial activity was dose dependent with a minimum bactericidal concentration (MBC) ranging from 0.17 to 10.12 μM (0.4–18.5 µg/ml) for Gram-negative and 0.94 to 20.65 μM (1.72-46.5 µg/ml) for Gram-positive bacteria. Interestingly, in high-salt environment, the antibacterial activity was generally maintained for Gram-negative bacteria. All peptides achieved complete bacterial killing in 20 min or less against Gram-negative bacteria. A linear time-dependent membrane permeabilization was observed for the tested peptides at 12.5 µg/ml. In a medium containing Mg2+ and Ca2+, the peptide combination with EDTA restores the antimicrobial activity particularly for AMP2041. Moreover, in combination with anti-infective agents (quinolones or aminoglycosides) known to bind divalent cation, AMP126 and AMP2041 showed additive activity in comparison with colistin. Our results suggest the following: (i) there is excellent activity against Gram-negative bacteria, (ii) there is low cytolytic activity, (iii) the presence of a chelating agent restores the antimicrobial activity in a medium containing Mg2+ and Ca2+, and (iv) the MBC value of the combination AMPs–conventional antibiotics was lower than the MBC of single agents alone. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.

To unveil cognitive-nigrostriatal correlations in Parkinson's disease (PD), 30 de novo, drug-naive PD patients and 15 patients with essential tremor (Controls, CTR) underwent a neuropsychological (NPS) battery and brain SPECT with [I-123]Ioflupane, as a biomarker of nigrostriatal function. Automatic extraction of uptake at caudate and putamen level was conducted through the BasGan software, also allowing partial volume effect correction. Because of the multicollinearity among neuropsychological tests and among SPECT variables, factor analysis was applied to 16 neuropsychological scores; moreover, the four SPECT variables were merged into a mean SPECT value (mSPECT). Factor analysis identified four NPS factors: a dys-executive (NPS-EX), a visuospatial (NPS-VS), a verbal memory (NPS-VM), and a "mixed" (NPD-MIX) factor. In PD group, there were inverse correlations between UPDRS-III score and both NPS-VS (P < 0.01) and mSPECT (P < 0.05), and a direct correlation between mSPECT and NPS-EX (P < 0.05). Post hoc analysis showed a direct correlation between NPS-EX and caudate uptake in both hemispheres (P < 0.05). Moreover, inverse correlations were found between UPDRS-III and, respectively, putamen uptake in the less affected hemisphere (P < 0.01), and putamen and caudate uptake in the more affected hemisphere (P < 0.05). In CTR, no correlation was found between mSPECT and either NPS or GDS values. Nigro-caudate function affects executive capabilities in PD but not in CTR, which appears to be unrelated to the disease motor severity at its onset. Instead, PD motor severity is related to nigro-putaminal impairment and visuospatial dysfunction. The role of these data as predictive features of cognitive decline and eventually dementia remains to be established in longitudinal studies.

1H spectra at 270 MHz of the beta h-endorphin glycyl residues in aqueous solution are reported. The chemical shifts, coupling constants and temperature coefficients are compared with those of the glycyl residues in Met-enkephalin and in a random coil model peptide. The local conformation of Tyr-Gly-Gly-Phe-segment observed in Met-enkephalin is maintained in beta h-endorphin.

Fabrication of dielectric nanotubes from silicon dioxide and silicon nitride by a template-based electron cyclotron resonance (ECR) plasma-enhanced (PE) CVD is described. The nanotubes synthesized from SiH 4 -O 2 and SiH 4 -N 2 binary source reagent systems are smooth, transparent and at least 10 μm long. A mathematical description of the template-directed nanometer-scale CVD is developed to elucidate the appropriate process parameters that enable growth of high-aspect-ratio nanotubes with uniform wall thickness. The analysis of the model, by establishing general trends between process operating conditions and geometrical characteristics of the nanotubes, clarifies the mechanism of nanoscale CVD. The dielectric nanotubes obtained provide many opportunities for fabricating composite nanostructures and nanodevices.

The new title compound is prepared by solid state reaction of a stoichiometric mixture of PbO, MnCO3, and WO3 (N2 stream, 800 °C for 2 h and 820 °C for 4 h).

Background Pseudomonas aeruginosa (PA) may cause suppurative otitis externa with severe inflammation and ulceration in dogs. Multidrug resistance is commonly reported for this organism, creating a difficult therapeutic challenge. Objective The aim of this study was to evaluate the in vitro antimicrobial activity of a gel containing 0.5 μg/mL of antimicrobial peptide AMP2041, 0.07% chlorhexidine digluconate (CLX), 0.4% Tris and 0.1% EDTA on 30 clinical isolates of PA from canine otitis externa. Materials and Methods Antimicrobial activity was evaluated through minimal bactericidal concentration (MBC). Standardized bacterial suspensions were incubated with different concentrations of the gel at 37°C for 30 min and plated for colony forming unit (CFU) counts. Time-to-kill kinetics were evaluated with the undiluted product and at MBC for each PA strain at 30 s, 1, 5, 10, 15, 30 min, 24 and 48 h. Results The MBC was 1:64 for two of 30 strains, 1:128 for 15 of 30 strains and 1:256 for 13 of 30 strains. The geometric mean was 1:165, equivalent to a concentration of 0.003 μg/mL AMP2041 + 0.0004% CLX + 0.0024%Tris + 0.0006% EDTA. Time-to-kill assays with the undiluted product showed complete bactericidal effect within 30 s for all isolates, whereas at the MBC this effect was reached within 5 min for 20 of 30 isolates and within 30 min for all isolates. Bactericidal activity was maintained after 48 h for all isolates. Conclusion This gel has shown rapid, complete and long-lasting activity against a panel of 30 PA isolates from cases of canine otitis externa.

(E)-2-Methyl-1,3-pentadiene was polymerized with the AlEt2Cl-Nd(OCOC7H15)3-Al(iBu)3 system to a polymer consisting of 98–99% 1,4-cis-structure. The crude polymer was fractionated by successive extractions with boiling diethyl ether, heptane and toluene. Examination of the soluble fractions and of the residue to toluene extraction by NMR, X-ray and DSC techniques indicated that the crude polymer consists of macromolecules differing in stereoregularity. Evidence is reported that the crystalline residue after the toluene extraction has a 1,4-cis-isotactic structure. The existence of two different crystalline phases is shown and the respective cell parameters have been determined. α-Phase: a = 10,74, b = 13,04, c = 7,87 A (−120°C), space group Pbca, Z = 8, Dc = 1,00 g · cm−3. β-phase: a = 9,30, b = 7,73, c = 7,90 A (25°C), space group P212121Z = 4, Dc = 0,96 g · cm−3.

1H spectra at 270 MHz of zwitterionic Met-enkephalin pentapeptide (Tyr-Gly-Gly-Phe-Met) in (C2H3)2SO/water mixtures are reported and discussed in terms of solvent-induced conformational transitions. The analysis of the chemical shifts, line widths, coupling constants and rotamer populations around chi 1 and chi 2 suggests that the conformational properties of Met-enkephalin in the two solvents are quite different. In aqueous solution, the preferred structure, characterized by the absence of intramolecularly hydrogen-bonded NH groups and head-to-tail interactions, very likely is an equilibrium of unfolded conformations with approximately equal energy. In (C2H3)2SO, the preferred structure is folded, with the Met-5 NH intramolecularly bonded and the Gly-3 NH protected from the solvent, while the Gly-2 and Phe-4 amide protons are solvent exposed. A conformational transition of Met-enkephalin from the intramolecularly bonded to the unbonded one takes place at about 40 mol-% water in (C2H3)2SO, involving the Met-5 NH proton and the Tyr-Gly-Gly fragment. The Phe-4 and Met-5 phi angles do not change appreciably, which suggest that an inversion at the Gly-3 residue of the folded form, responsible for the conformational transition, does not affect the C-terminal moiety. At about 70 mol-% water in (C2H3)2SO a change in the solvent mixture properties affects the chi 1 rotamer populations and the ring dynamics of the aromatic side chains. The line broadening of the Tyr-1 delta and epsilon proton resonances indicates a specific interaction of the N-terminal ring with the solvent.

1H spectra at 270 MHz of the Met-enkephalin pentapeptide (Tyr-Gly-Gly-Phe-Met) in aqueous solution, as a function of pH and of temperature, are reported. The analysis of the chemical shifts, line widths, coupling constants and rotamer populations around χ1 and χ2, suggests the existence of three conformational regions in the pH range 1–10, due to some rearrangements of the first two amino acids, Tyr-1 and Gly-2. A first conformational transition occurs corresponding to the N-terminus titration, with an exchange rate between conformational states which is not too fast. The second transition occurs concomitantly with the phenolic group titration. The conformational states of the cationic and zwitterionic forms are probably very similar and are characterized by the absence of intramolecular hydrogen bonds and of head-to-tail interactions. A bent structure, with the Tyr-1 ring Facing the Gly-2 could contribute to the equilibrium of the conformational states of Met-enkephalin in the pH range 8–10. This structure could be destabilized as a consequence of the phenolic group deprotonation. The Met-5 and Phe-4 residues appear to have little sensitivity to the conformational transitions of the backbone and both show a settling of the side chains corresponding to the carboxyl group titration, thus showing a reciprocal steric hindrance. The temperature coefficients of the chemical shifts of amide protons at acidic pH are in the range of solvated peptides. In the temperature range 0–75°C, the 3JαNH coupling constants were independent of temperature.

The homopolymerization of 2,3-dimethyl-1,3-butadiene with the catalyst system AlEt2Cl-Co(acac)2 affords polymers consisting of about 81% cis-1,4-units and 19% 1,2-units. The copolymerization of 1,3-butadiene/2,3-dimethyl-1,3-butadiene using the same system is of the ideal type and the composition of the copolymers is practically identical with that of the monomer mixture. The structure of the copolymers depends on their composition. The butadiene units, which are more than 95% cis-1,4 in the homopolymer, become partially 1,2 in the copolymers; their amount increases with increasing dimethylbutadiene content. Conversely, the fraction of dimethylbutadiene units with 1,2-structure decreases in the copolymers with increasing butadiene content. In the copolymers containing more than 50% of butadiene, the dimethylbutadiene units are practically all cis-1,4. The analysis of sequence distribution shows that the 1,2-butadiene units in the copolymers are not randomly distributed but are mostly adjacent to dimethylbutadiene units. The results obtained with dimethylbutadiene are compared with those reported for the homopolymerization of isoprene and the copolymerization of isoprene/butadiene using the same catalyst system.

The IR spectra of six atactic and five isotactic deuterated polypropylenes are reported. The vibrational assignment is discussed based on a careful mutual comparison of the spectra in addition to a comparison with those already known from the literature. Es wird uber die IR-Spektren von sechs ataktischen und funf isotaktischen deuterierten Polypropylenen berichtet. Die Zuordnung der Schwingungen wird anhand sorgfaltigen Vergleichs der Spektren sowohl untereinander als auch mit denen der Literatur diskutiert.