Microchemistry and Mechanisms of Adherence in Steel/Enamel Interfaces

The microchemistry of steel/enamel interfaces was investigated, on a nearly atomic scale, by means of X-ray photoelectron spectroscopy. Experimental evidence is given that good adherence is characterized by a fully reacted iron silicate phase, which produces a local chemical continuity between steel and enamel, whereas bad adherence is associated with a heterogeneous mixture of an iron silicate phase plus unreacted FeO.     

Radiographical assessment of interphalangeal rotation in the evaluation of equine digital conformation

The purpose of this double-blind study was to evaluate the effectiveness of a commercially available fluoride lacquer (Bifluorid 12) containing CaF2 (6%) and NaF (6%) in reducing dentine hypersensitivity. A fluoride lacquer containing only NaF (6%) served as a control. Twenty-five adult patients complaining about at least two hypersensitive teeth participated in this study. In each patient and at each appointment, one tooth was treated with Bifluorid 12, while the other was treated with the control substance. Sensitivity levels were determined before and after the application of each lacquer at baseline as well as at 1, 2 and 3 weeks after the start of study. The final evaluation of hypersensitivity was performed at 4 weeks, and follow-ups were undertaken at 6 and 12 months. A reproducible air blast stimulus and a visual analogue scale were used for evaluation. Results demonstrated a distinct reduction of hypersensitivity after 1, 2 and 3 weeks in the Bifluorid 12 group. Initially, no obvious effects could be observed in the control group. However, a clear alleviation could be observed after 2 and 3 weeks with the control. After 4 weeks, the overall sensitivity scores were comparably low, without any significant differences between the two fluoride lacquers. In both groups, the effects of treatment were seen over the 12-month observation period. Bifluorid 12 was considered at least comparable to the control. It is concluded from this study that Bifluorid 12 is effective in the initial reduction of dentine hypersensitivity. The combination of CaF2/NaF can be recommended for clinical use.     

Can a local histogram really map texture information?

This paper presents a methodology to extract information from a set of r labeled counts with constant sum N called an “Organ Pipe Diagram (OPD)”. A histogram is a particular OPD with an order relation on its count labels.As an application of this methodology, if a global image of radiometries is scanned by a window, a “module” value and a “state” can be defined for the local histogram. The corresponding maps of modules and states yield a useful local spatial information closely related to texture. The methodology is interesting in itself, as it shows how a geometry can be built-up from a set of labeled counts whose space of definition is shown to be a simplex.     

M&M's: Building Binary Software Components for Supporting Mobile-Agent Enabled Applications

Mobile Agents provide a new promising paradigm for developing distributed applications. Nevertheless, although the basic concept has been around for some years and many agent platforms are available both from the industry and research community, there are currently few examples where the technology has been deployed in the real world. One important reason for this is that using the current available agent frameworks it is quite difficult to develop applications without having to center them completely on the agents and on the agent infrastructure. In this paper, we present the M&M project, taking place at the University of Coimbra. In this project, we are developing an extensive component-based framework that enables ordinary applications to use mobile agents in a flexible and easy way. By using this approach, applications can be developed using current object-oriented approaches and become able of sending and receiving agents by the simple drag-and-drop of mobility components. The framework was implemented using the JavaBeans component model and provides integration with ActiveX, which allows applications to be written in a wide variety of programming languages. By using this framework, the development of applications that can make use of mobile regents is greatly simplified, which can contribute to a wider spreading of the mobile agent technology.     

Direct observation in the millisecond time range of fluorescent molecule asymmetrical interaction with the electropermeabilized cell membrane

Interaction of two stains (propidium iodide and ethidium bromide) with electropermeabilized living Chinese hamster ovary cells is observed using an ultrafast fluorescence image acquisition system. The computing process is linked to an ultra-low-light intensifying camera working with a very short time resolution (3.33 ms per image). Altered parts of the cell membrane were identified via the enhancement in fluorescence intensity of the dyes. They reflect the electropermeabilized part of the membrane in which free flow of dye occurred. Images of the fluorescence interaction patterns of the two dyes, in a maximum 20-ms time lag after pulsation, reveal asymmetrical permeabilization of the cell membrane. For electric field intensities higher than a first threshold value, permeabilization is always observed on the anode-facing side of the cell. For electric field intensities over a second higher threshold value, the two electrode-facing hemispheres of the cell are permeabilized, the hemisphere facing the anode being most permeable. These data support the conclusion that electropermeabilization of living cell membrane is affected by its resting potential. The asymmetrical pattern of the dye interaction is not dependent on the nature or concentration of the dye, the ionic strength of the pulsing buffer, or the duration of the pulse. The field intensity determines the fraction of the membrane in which molecular alterations can occur. The extent of alteration in this localized region is determined by the duration of the pulse when a single pulse in the millisecond time range is applied.     

A hydrocarbon-soluble difunctional orgaolithium anionic initiator. Synthesis of 2,2-bis[3-(1-lithio-2,3-dimethylpentyl)-4-methoxyphenyl]propane

The reaction of stoichiometric amounts of sec-butyllithium with 2,2-bis[3-(1-propenyl)-4-methoxyphenyl]propane ( 4 ) produces a new difunctional organolithium initiator, 2,2-bis[3-(1-lithio-2,3-dimethylpentyl)-4-methoxyphenyl] propane, which is soluble in hydrocarbon solvent in the absence of any polar additive. Following isolation and purification by gas liquid chromatography, the structures of ( 4 ) and the methanolysis product of the difunctional initiator were characterized by ¹H NMR, FTIR and mass spectroscopy and elemental analysis. The dilithium initiator is effective for the polymerization of 1,3-butadiene and allows the preparation of polybutadienes with predictable molecular weights, narrow, monomodal molecular weight distribution and low 1,2-diene microstructure.     

Effects of Conditioning During Amygdalar Inactivation on Training-Induced Neuronal Plasticity in the Medial Geniculate Nucleus and Cingulate Cortex in Rabbits (Oryctolagus cuniculus).

This study addressed the amygdala's role in avoidance conditioning in rabbits (Oryctolagus cuniculus). Intra-amygdalar muscimol infusion before 60 or 120 conditioning trials blocked training-induced neuronal activity (TIA) in the medial geniculate (MG) nucleus. One hundred twenty trials with muscimol blocked TIA permanently, during conditioning with muscimol and then later without muscimol; 60 trials with muscimol blocked TIA only when muscimol was present. Cingulate cortical TIA was blocked only when muscimol was present. Behavioral learning did not occur with muscimol, but later learning was facilitated (i.e., savings occurred) in rabbits initially given muscimol plus training. These results define the time period wherein amygdalar processes initiate TIA in the MG nucleus and suggest that distinct forms of amygdalar processes induce TIA in the MG nucleus and cingulate cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)