Patterns of stability in adult attachment: An empirical test of two models of continuity and change.

One of the core assumptions of attachment theory is that attachment representations are stable over time. Unfortunately, the data on attachment stability have been ambiguous, and as a result, alternative theoretical perspectives have evolved to explain them. The objective of the present research was to evaluate alternative models of stability by studying adults in 2 intensive longitudinal investigations. Specifically, we assessed attachment representations in 1 sample (N = 203) daily over a 30-day period and in the other sample (N = 388) weekly over a year. Analyses show that the patterns of stability that exist in adult attachment are most consistent with a prototype model—a model assuming that there is a stable factor underlying temporary variations in attachment. Moreover, although the Big Five personality traits exhibited a pattern of stability that was similar to that of attachment, they did not account for the stability observed in attachment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Molding Micropatterns of Elasticity on PEG‐Based Hydrogels to Control Cell Adhesion and Migration

We present an innovative and simple, soft UV lithographic method “FIll‐Molding In Capillaries” (FIMIC) that combines soft lithography with capillary force driven filling of micro‐channels to create smooth hydrogel substrates with a 2D micro‐pattern on the surface. The lithographic procedure involves the molding of a polymer; in our case a bulk PEG‐based hydrogel, via UV‐curing from a microfabricated silicon master. The grooves of the created regular line pattern are consequently filled with a second hydrogel by capillary action. As a result, a smooth surface is obtained with a well‐defined pattern design of the two different polymers on its surface. The FIMIC method is very versatile; the only prerequisite is that the second material is liquid before curing in order to enable the filling process. In this specific case we present the proof of principle of this method by applying two hydrogels which differ in their crosslinking density and therefore in their elasticity. Preliminary cell culture studies on the fabricated elasticity patterned hydrogels indicate the preferred adhesion of the cells to the stiffer regions of the substrates, which implies that the novel substrates are a very useful platform for systematic cell migration studies, e.g. more fundamental investigation of the concept of “durotaxis”.     

Innovative Process for the Synthesis of Nanostructured Ruthenium Catalysts and their Catalytic Performance

An efficient, reproducible process for the solvothermal synthesis of Ru/γ-Al₂O₃ nanocatalysts has been developed. This synthesis employs a low boiling point alcohol acting as solvent and reducing agent. The reaction is performed in autoclave under nitrogen overpressure, by heating the solution of metal precursor and stabilizing agent in the presence of the support. These systems show very promising performances, also with an application perspective, in the selective hydrogenation of phenol to cyclohexanone carried out at 160 °C under 5 MPa of hydrogen: a selectivity to cyclohexanone as high as 83% has been reached at a phenol conversion value of 88%. This paper is dedicated to the memory of Professor Carlo Carlini, with great sorrow.     

New synthetic seven-membered 1-azasugars displaying potent inhibition towards glycosidases and glucosylceramide transferase

Several members of a new family of seven-membered azasugars, which can be seen as 1-azasugar ring homologues, have been obtained by simple chemical transformations starting from a sugar-derived azidolactol. Unlike their piperidine counterparts, these molecules are chemically stable when they possess a hydroxy group at the pseudo-C-2 position. Biological assays with a range of carbohydrate-processing enzymes have revealed interesting potential for these compounds. A trihydroxymethyl-substituted azepane displayed strong competitive inhibition on almond beta-glucosidase (K(i)=2.5 microM) while a trihydroxylated carboxylic acid derivative proved to be a potent and selective L-fucosidase inhibitor (K(i)=41 nM). N-Butylation of these seven-membered 1-azasugars generated derivatives with some activity towards the Gaucher's disease-related glucosylceramide transferase (IC(50) 75 microM) that did not interact significantly with digestive glucosidases.     

Catalytic hydrodehalogenation as a detoxification methodology

Catalytic hydrodehalogenation is presented as a viable approach in the non-destructive treatment of concentrated halogenated aromatic gas streams to generate reusable raw material. Nickel loaded (from 1.5 to 20.3% w/w) silica catalysts have been used to hydrotreat a range of halogenated feedstock, where 473 K≤T≤573 K: chlorobenzene, chlorotoluene, chlorophenol, bromobenzene, dichlorobenzene, dichlorophenol, trichlorophenol, pentachlorophenol. The long term (up to 800 h-on-stream) stability of these catalysts has been assessed where the changes in nickel particle size and morphology as a result of the prolonged catalytic step was probed by TEM; each catalyst irrespective of any loss of initial activity was fully selective in solely promoting dehalogenation. In the case of a polychlorinated feedstock, dechlorination can proceed in a stepwise manner to generate a partially dechlorinated product. Hydrodehalogenation appears to occur via an electrophilic mechanism where the presence of electron-donating substituents on the benzene ring enhances the rate of reaction. The reaction is shown to be structure sensitive over Ni/SiO₂ where the hydrodechlorination rates and ultimate yield of the parent aromatic from a polychlorinated reactant is favored by larger nickel particle sizes. A direct contact of the freshly activated catalyst with HCl or HBr gas induced an appreciable growth of the supported metal crystallites. Chlorobenzene hydrodechlorination was suppressed on a HCl or HBr treated Ni/SiO₂ which promoted instead the unexpected growth of highly ordered carbon filaments; this carbon growth is characterized by TEM and SEM. The dependence of the experimental hydrodechlorination and hydrodebromination rates on the gas phase aromatic partial pressure (in the range 0.02–0.1 atm) is adequately represented by a kinetic model involving a non-competitive adsorption of hydrogen and halogenated aromatic where the incoming aromatic reactant must displace the hydrogen halide from the catalyst surface.     

Optimising sodium silica gel for Ferroin immobilization

The addition of compounds like enzymes or catalysts in silica gel matrix expand its applications as sensor material, controlled drug-delivery and photo-active material, as well as it allows the study of pattern generation in oscillating chemical reactions in dependence on spatial catalyst structures. Creating catalyst structures requires at the moment photolithography or emulsions. A simpler way of creating spatial catalyst structures in silica gels is spotting the catalyst onto the gel matrix. The result of this procedure mainly depends on the ability of the gel to absorb the catalyst and immobilise it in the desired structure in aqueous solutions. We investigate if the addition of polymers into the silica gel can enhance the immobilization of Ferroin, which is an indicator for redox potentials and a standard catalyst for the Belousov–Zhabotinsky reaction. Polyethylenglycol (PEG), poly-styrene sodium sulfate and poly-styrenesulfate-co-maleic acid sodium salt (PSS-co-PM) were tested. By optical measurements the immobilization was analyzed and scanning electron microscopy, energy dispersive X-ray spectroscopy and nuclear magnetic resonance measurements were applied for microstructure and chemical element analysis. We found that PEG and PSS-co-PM enhance the stability of Ferroin spots in silica gels. Thereby, PEG changes the silica gel microstructure without being incorporated into the solid gel, whereas PSS-co-PM is incorporated into the silica gel and (chemically) interacts with Ferroin.     

Nano Ca(OH)2 synthesis using a cost‐effective and innovative method: Reactivity study

Ca(OH)₂ nanoparticles in hydro‐alcoholic dispersion (nanolime) are currently used for eco‐compatible treatments of carbonate‐based substrates in the field of Cultural Heritage conservation. Unfortunately, at present nanolime is synthesized by processes which present some drawbacks (considerable cost, multiple steps, low specific production yield), thus limiting the potential of its applications. We have developed a single‐step procedure, based on an ion exchange process, making it possible to produce pure and crystalline Ca(OH)₂ nanoparticles easily in water, at room temperature and ambient pressure, starting from cheap or renewable reactants. The simplicity of the process and its time‐ and energy‐saving aspects are very promising factors for extending the production from laboratory to industrial scale. The aim of this paper is to investigate the structural and morphological features of the nanoparticles produced and to analyze the influence of crucial parameters of the synthesis process (i.e., time, water usage, reagent concentration and reaction volume) on the nanoparticles’ characteristics. The nanolime produced is investigated by XRD, FTIR, TEM, and AFM techniques. The nanoparticle reactivity in the carbonation process is also investigated, by varying the suspension concentration, the solvent and relative humidity conditions. Pure, crystalline, and very reactive Ca(OH)₂ nanoparticles are obtained. The nanoparticles are constituted of thin lamellas, composed of primary hexagonal nanoparticles <10 nm, irrespective of time, water employed, reagents concentration, and reaction volume.     

Moving Fourier Analysis for Locally Stationary Processes with the Bootstrap in View

We introduce a moving Fourier transformation for locally stationary time series, which captures the time‐varying spectral density in a similar manner as the classical Fourier transform does for stationary time series. In particular, the resulting Fourier coefficients as well as moving local periodograms are shown to be (almost all) asymptotically uncorrelated. The moving local periodogram is obtained by thinning the local periodogram to avoid multiple information present at different but close points in time. We obtain consistent estimators for the local spectral density at each point in time by smoothing the moving local periodogram. Furthermore, the moving Fourier coefficients, respectively periodograms, are well suited to adapt stationary frequency domain bootstrap methods to the locally stationary case. For the wild time frequency toggle bootstrap, it is shown that the corresponding bootstrap covariance of a global locally stationary bootstrap samples captures the time‐varying covariance structure of the underlying locally stationary time series correctly. Furthermore, this bootstrap in addition to adaptations of other frequency domain bootstrap methods is used in a simulation study to obtain uniform confidence bands for the time‐varying autocorrelation at lag 1. Finally, this methodology is applied to a wind data set.     

Concentration effect of <Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide on viscoelastic properties of hydrosoluble thermo-thickening copolymers

In this work, we described the preparation of hydrosolubles thermosensitive copolymers obtained via free radical polymerization in aqueous media. The reactions were carried out under different molar ratio of acrylamide and N-isopropylacrylamide (NIPAM) and are considered [80]/[20], [60]/[40], [50]/[50], [40]/[60] and [20]/[80], respectively. The initial concentration of monomer mixture was kept at 3% (weight) based on the water volume. The polymerizations were performed at 70 °C under mechanical agitation during 7 h and the molar ratio between monomer and initiator (4,4′-azobis cyano pentanoic acid) was kept at 0.07%. The copolymers were characterized and results demonstrated that the monomer concentrations were closed to previously feed to the reaction. The turbidity point rises according to the quantity of poly(acrylamide), PAM, incorporated into the copolymers (composition value). Also, it was observed that the molecular weight of each copolymer decreases when the amount of NIPAM increases. On the other hand, the viscosity of all copolymers growth compared to the increase in the temperature from 25 to 70 °C is observed. Notwithstanding, in the case of copolymer with highest NIPAM concentration (CP5), the viscosity decreases in the temperature range from 60 to 70 °C.