Analysis and intervention with two topographies of challenging behavior exhibited by a young woman with autism

We determined whether tumour size in vivo and cell density in vitro modulate the expression of the mdr-1 gene in B16 melanoma cells. Cells were injected subcutaneously into syngeneic mice. Small (5 mm in diameter) and large (15-20 mm in diameter) tumours were harvested. Tumour cells from small subcutaneous tumours exhibited higher levels of mdr-1 mRNA (measured using Northern blot and in situ hybridization) and P-glycoprotein (P-gp) (measured using immunohistochemistry and fluorescent activated cell sorter analysis), as well as greater. In vitro resistance to doxorubicin (DXR) than cells from large subcutaneous tumours. immunohistochemical studies using an antibody against proliferating cell nuclear antigen revealed that the small subcutaneous tumours contained a larger fraction of proliferating cells than the large tumours. To determine whether cell proliferation correlated with expression of mdr-1, we plated B16-F10 cells to yield sparse and confluent monolayer cultures. The levels of mdr-1 mRNA and P-gp and resistance to DXR and phosphotyrosine activity were higher in the sparse cultures than in the confluent cultures. These results demonstrate an intratumoral heterogeneity for the expression of mdr-1 that directly correlates with intratumoral heterogeneity for cell division.     

From contact angle titration to chemical force microscopy: a new route to assess the pH-dependent character of the stratum corneum

Despite of its complex multicomponent organization and its compact architecture, the Stratum corneum (SC) is not completely impermeable to substances directly applied on the skin surface. A huge number of works have been dedicated to the understanding of the mechanisms involved in substance permeation by exploring deeper layers than the SC itself. Surprisingly, there is a poor interest in studies relating to interactions which may occur in the near-surface region (i.e. approximately 1 nm depth) of the SC. In this work, equilibrium proton-transfer reactions have been used as probes to define in a fundamental point of view the nature of the SC interactions with its environment. Such titration curves are investigated on 'in vitro' SC (isolated SC from abdominal skin tissue) and on 'in vivo' volar forearm (a sebum poor area). The results are discussed in term of work of adhesion and surface pKa values. Because SC can 'reconstruct' under heating, influence of the temperature on titration curves is investigated and the role of the different components is discussed. Different sigmoidal transitions were observed. Two common pKa values (pKa(1) = 4 and pKa(2) = 11.5) were clearly identified in both cases and associated to an acid-base character. By playing with the temperature of 'in vitro' SC, the 'accessibility' of polar functions was increased, thus refining the results by revealing an amphoteric character with an acid-to-base transition at pH 3.5 and two acid transitions at pH = 6.5 and pH = 11.5. Adhesion forces between an Atomic Force Microscopy (AFM) tip and a single isolated corneocyte through buffered liquid media were also investigated to better understand the role of the individual corneocytes.     

Ku‐band diurnal fade characteristics and fade event duration data from three,two‐year,Earth–space radiometric experiments in Equatorial Africa

The move to provide direct to home (DTH) multi‐media services from satellites requires a number of new insights to be gleaned from the propagation effects that occur along satellite‐to‐ground paths. Annual statistics will not be sufficient to describe the likely performance of the link, nor will they provide information on the likely customer acceptance of the DTH service. What are required are the likely number of outages due to rain attenuation in a given period, their duration, the time between the outages, and the diurnal characteristics of rain attenuation along the link. This paper presents results obtained in three, two‐year, Ku‐band experiments in tropical Africa on diurnal attenuation effects, as well as on rain and attenuation event duration and inter‐event duration. The implications of the results are discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Ultrasonic cavitation test applied to thin metallic films for assessing their adhesion with mercaptosilanes and surface roughness

Evaluating the adhesion of micrometer or nanometer thick coatings is a challenging question which concerns many application fields. This is especially true for thin films deposited on a substrate of elastic modulus higher than that of the film, or for granular coatings, that do not allow the use of common adhesion tests. Usually, applied to characterize the wear resistance of bulk materials or thick coatings, the ultrasonic cavitation test is applied here to evaluate the adhesion strength of gold and copper thin films (~200 nm) that are evaporated on a silicon substrate. The test is shown to be sensitive enough to discriminate the influence of the surface chemistry on the adhesion strength of gold and copper films. Particularly, the role of (3-mercaptopropyl)triethoxysilane as an effective adhesion promotor is demonstrated. Furthermore, the role of surface roughness of the substrate is characterized and discussed in order to get further insights on the way this parameter interferes with the ultrasonic test and determines the adhesive strength of the coating. An estimate of the adhesive strength is given on the basis of the coating delamination kinetics.     

Morphology-dependent properties and swelling-induced transition in ‘sodium-alginate/urea’ thin films

The paper investigates the competing and morphology-dependent wetting and imbibition behaviours of ‘sodium-alginate/urea’ films that are currently used as thickeners in inkjet printing processes, dealing specifically with the structural changes of the coating within the swelled spot of the contacting (wetting) liquid drop. Depending on the initial morphology of the coating, the re-drying of the swelled wetting spot was found to lead to re-crystallization morphologies that are qualitatively different in both their texture and physicochemical properties. Well beyond the investigated ‘alginate/urea’ mixture, these results well highlight the critical influence that swelling-induced morphological re-constructions might have on interface phenomena in general, and in particular, on the wetting, impregnation and adhesion of solvent-processed polymeric assemblies.     

Sensitivity enhancement of OD- and OD-CNT-based humidity sensors by high gravity thin film deposition technique

The humidity sensing properties of the thin films of an organic semiconductor material orange dye(OD)and its composite with CNTs deposited at high gravity conditions have been reported. Impedance, phase angle, capacitance and dissipation of the samples were measured at 1 kHz and room temperature conditions. The impedance decreases and capacitance increases with an increase in the humidity level. It was found that the sensitivity of the OD-based thin film samples deposited at high gravity condition is higher than the samples deposited at low gravity condition. The impedances and capacitance sensitivities of the of the samples deposited under high gravity condition are 6.1 times and 1.6 times higher than the films deposited under low gravity condition.     

Characterisation of volatile compounds in Tunisian fenugreek seeds

In this study, we intend to develop a simple and fast analytical procedure to identify the volatile compounds implicated in the odour of Tunisian fenugreek (Trigonella foenum-graceum L.) seeds. Two procedures, solvent extraction and static headspace solid-phase microextraction (SHS-SPME), have been used under different conditions. The volatile compounds extracted were systematically identified using gas chromatography–mass spectrometry, based on their mass spectrum and Kovats index on two columns of different polarity. A total of 67 compounds were identified, some of them being reported for the first time in fenugreek seeds (e.g. several pyrazines, 2,5-dimethyl-4-hydroxy-3(2H)-furanone or 1-epi-cubenol). Methanol was found to be the preferred solvent for high and medium boiling point volatile compounds, such as sotolone and nitrogen compounds. For SHS-SPME, the fibre coated with divinylbenzene/carboxen/polydimethylsiloxane 2 cm was the most suitable for extracting volatile compounds from ground seeds. The efficiency of this fibre was confirmed by direct gas chromatography–olfactometry, with a global odour similar to that of fenugreek seeds.     

Rain side-scatter interference in the satellite links of the 1990s

In addition to inducing attenuation and depolarization in satellite links, scattering by rain can create intersystem interference. This type of interference was investigated extensively in the 1970s for terrestrial paths, but little has been done to study its effects on modern and future satellite links. Studies of the potential interference created by the scattering of an uplink signal into an adjacent satellite and the inverse case where a downlink signal is scattered into the earth station of an adjacent satellite system are reported. Two computation methods for the interfering power are presented. The first, based on the bistatic radar equation, takes only the first-order multiple scattering into account, whereas the second method, based on the radiative transfer equation, includes higher orders of multiple scattering