Effects of nicotine on affect are moderated by stressor proximity and frequency, positive alternatives, and smoker status

The Situation x Trait Adaptive Response (STAR) model hypothesizes that nicotine reduces negative and enhances positive affect to a greater degree in situations involving internally driven attention, as when stressor stimuli are distal (past or future), thereby allowing nicotine-primed biasing of attentional processing away from negative and toward positive stimuli. To test this hypothesis, the effects of nicotine were assessed in 64 smokers and 64 never-smokers, half of whom viewed emotionally negative pictures in a no-choice picture attention task that required them to focus on the picture stressors. The other half viewed the same stimuli in a two-choice picture attention task that presented stressor pictures in one visual field and simultaneously presented positive or neutral pictures in the other visual field. Participants received a nicotine patch during one session and a placebo patch during the other session. Nicotine modulated affect only in smokers. In smokers, compared with placebo, nicotine patch reduced negative affect more during the distal periods (between stressors) than during actual stressor exposure and in women reduced negative affect more when the proportion of negative stimuli was low. Nicotine also enhanced positive affect more during distal than proximal stressors. Nicotine tended to reduce eye-gaze at negative pictures, especially when the alternative picture was positive. The overall findings are consistent with the view that nicotine biases attention away from negative stimuli when equally salient positive or benign stimuli are present.     

The effect of thermal treatment on the structure and fine structure of Cu-Zn-Al martensite

The effect of thermal treatment on the structure and fine structure of CU-17.4Zn-13.0Al (at%) matensite has been studied using X-ray powder diffraction and transmission electron microscopy. It has been found that when the directly-quenched M18R₁ martensite is aged at increasing temperatures, the structure parameters andx-parameter tend evidently towards the values of the N18R₁ martensite, while the DO₃-derived long-range order parameterS is not changed substantially. The activation energy of the structure parameter variation process of the 18R₁ martensite during aging has been measured to be 58 kJ mol^–1 (0.60 eV) for the directly-quenched specimen using the X-ray reflection splitting data. The aging kinetics of the step-quenched martensite is much lower compared with the directly-quenched martensite. Moreover, the anti-phase domain size of the step-quenched martensite inherited from the parent phase is much larger than that of the directly-quenched and the aged martensites. Based on our observations the mechanisms of the aging and stabilization of martensite are discussed.     

Fast display of illuminated field lines

A new technique for interactive vector field visualization using large numbers of properly illuminated field lines is presented. Taking into account ambient, diffuse and specular reflection terms, as well as transparency and depth cueing, we employ a realistic shading model which significantly increases the quality and realism of the resulting images. While many graphics workstations offer hardware support for illuminating surface primitives, usually no means for an accurate shading of line primitives are provided. However, we show that proper illumination of lines can be implemented by exploiting the texture mapping capabilities of modern graphics hardware. In this way, high rendering performance with interactive frame rates can be achieved. We apply the technique to render large numbers of integral curves of a vector field. The impression of the resulting images can be further improved by a number of visual enhancements, like color coding or particle animation. We also describe methods for controlling the distribution of field lines in space. These methods enable us to use illuminated field lines for interactive exploration of vector fields     

Zinc in primary teeth from children in Norway

Human primary teeth have been used as indicators of exposure to several heavy metals both in Norway and elsewhere. Local dentists in all 19 counties of Norway collected 2747 primary teeth during 1990-1994. Samples of tooth powder from whole, ground teeth were analyzed for zinc concentration by flame atomic absorption spectrophotometry. The overall geometrical mean was 144.5 micrograms of Zn/g of tooth substance (S.D. = 1.6). The result represents a small increase (5.2%) compared with a similar investigation in the 1970s. However, the mean zinc concentrations in the geographically matching parts of the two materials did not differ significantly. The variation in tooth zinc concentrations between the different counties declined from the 1970s to the 1990s. We found no correlation between the tooth zinc concentration and available environmental data on zinc in drinking-water, discharge of zinc from industrial point sources or population density in the same geographical areas. The zinc concentrations varied significantly with caries status, tooth type and root length. Few samples had a zinc concentration below 90 micrograms/g, indicating that most children consume sufficient zinc. Some very high values could not immediately be explained, but may be caused by contamination from zinc-containing dental restorations.     

Syntheses of Octa(2‐heteroaryl) Azaphthalocyanines

Magnesium, copper(II) and nickel(II) complexes of octasubstituted azaphthalocyanines 3 — 5 have been prepared from di‐fur‐2‐yl, di‐thien‐2‐yl and di‐pyrid‐2‐yl pyrazine‐2,3‐dicarbonitriles 2 . Compounds 2 were prepared in good yields from condensations of diaminomaleonitrile and the diketones 2,2′‐furil, 2,2′‐thenil and 2,2′‐pyridil. AzaPcs 3—5 give green pyridine solutions with Q‐bands at 650—670 nm and ε‐values of 60 000—190 000.     

Chronic administration of eicosapentaenoic acid and docosahexaenoic acid as ethyl esters reduced plasma cholesterol and changed the fatty acid composition in rat blood and organs

Fish oils rich in n-3 fatty acids have been shown to decrease plasma lipid levels, but the underlying mechanism has not yet been elucidated. This investigation was performed in order to further clarify the effects of purified ethyl esters of eicosapentaenoic acid (EPA-EE) and docosahexaenoic acid (DHA-EE) on lipid metabolism in rats. The animals were fed EPA-EE, DHA-EE, palmitic acid, or corn oil (1 g/kg/d) by orogastric intubation along with a chow background diet for three months. At the end the animals were sacrificed. Plasma and liver lipids were measured, as well as lipid-related enzyme activities and mRNA levels. The fatty acid composition of plasma and different tissues was also determined. This study shows that, compared to the corn oil control, EPA-EE and DHA-EE lowered plasma cholesterol level, whereas only EPA-EE lowered the amount of plasma triacylglycerol. In liver peroxisomes, both EE preparations increased fatty acyl-CoA oxidase FAO activities, and neither altered 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activities. In liver microsomes, EPA-EE raised HMG-CoA reductase and acyl-CoAicholesterol acyltransferase activities, whereas DHA-EE lowered the former and did not affect the latter. Neither product altered mRNA levels for HMG-CoA reductase, low density lipoprotein-receptor, or low density lipoprotein-receptor related protein. EPA-EE lowered plasma triacylglycerol, reflecting lowered very low density lipoprotein secretion, thus the cholesterol lowering effect in EPA-EE-treated rats may be secondary to the hypotriacylglycerolemic effect. An inhibition of HMG-CoA reductase activity in DHA-EE treated rats may contribute to the hypocholesterolemic effect. The present study reports that 20∶5n-3, and not 22∶6n-3, is the fatty acid primarily responsible for the triacylglycerol lowering effect of fish oil. Finally, 20∶5n-3 was not converted to 22∶6n-3, whereas retroconversion of 22∶6n-3 to 20∶5n-3 was observed.     

In Vitro Treatment of Melanoma Brain Metastasis by Simultaneously Targeting the MAPK and PI3K Signaling Pathways

Malignant melanoma is the most lethal form of skin cancer, with a high propensity to metastasize to the brain. More than 60% of melanomas have the BRAF^V600E mutation, which activates the mitogen-activated protein kinase (MAPK) pathway [1]. In addition, increased PI3K (phosphoinositide 3-kinase) pathway activity has been demonstrated, through the loss of activity of the tumor suppressor gene, PTEN [2]. Here, we treated two melanoma brain metastasis cell lines, H1_DL2, harboring a BRAF^V600E mutation and PTEN loss, and H3, harboring WT (wild-type) BRAF and PTEN loss, with the MAPK (BRAF) inhibitor vemurafenib and the PI3K pathway associated mTOR inhibitor temsirolimus. Combined use of the drugs inhibited tumor cell growth and proliferation in vitro in H1_DL2 cells, compared to single drug treatment. Treatment was less effective in the H3 cells. Furthermore, a strong inhibitory effect on the viability of H1_DL2 cells, when grown as 3D multicellular spheroids, was seen. The treatment inhibited the expression of pERK1/2 and reduced the expression of pAKT and p-mTOR in H1_DL2 cells, confirming that the MAPK and PI3K pathways were inhibited after drug treatment. Microarray experiments followed by principal component analysis (PCA) mapping showed distinct gene clustering after treatment, and cell cycle checkpoint regulators were affected. Global gene analysis indicated that functions related to cell survival and invasion were influenced by combined treatment. In conclusion, we demonstrate for the first time that combined therapy with vemurafenib and temsirolimus is effective on melanoma brain metastasis cells in vitro. The presented results highlight the potential of combined treatment to overcome treatment resistance that may develop after vemurafenib treatment of melanomas.     

Visual Analysis of Biomolecular Cavities: State of the Art

In this report we review and structure the branch of molecular visualization that is concerned with the visual analysis of cavities in macromolecular protein structures. First the necessary background, the domain terminology, and the goals of analytical reasoning are introduced. Based on a comprehensive collection of relevant research works, we present a novel classification for cavity detection approaches and structure them into four distinct classes: grid‐based, Voronoi‐based, surface‐based, and probe‐based methods. The subclasses are then formed by their combinations. We match these approaches with corresponding visualization technologies starting with direct 3D visualization, followed with non‐spatial visualization techniques that for example abstract the interactions between structures into a relational graph, straighten the cavity of interest to see its profile in one view, or aggregate the time sequence into a single contour plot. We also discuss the current state of methods for the visual analysis of cavities in dynamic data such as molecular dynamics simulations. Finally, we give an overview of the most common tools that are actively developed and used in the structural biology and biochemistry research. Our report is concluded by an outlook on future challenges in the field.     

A Visual Tool for the Analysis of Algorithms for Tomographic Fiber Reconstruction in Materials Science

We present visual analysis methods for the evaluation of tomographic fiber reconstruction algorithms by means of analysis, visual debugging and comparison of reconstructed fibers in materials science. The methods are integrated in a tool (FIAKER) that supports the entire workflow. It enables the analysis of various fiber reconstruction algorithms, of differently parameterized fiber reconstruction algorithms and of individual steps in iterative fiber reconstruction algorithms. Insight into the performance of fiber reconstruction algorithms is obtained by a list‐based ranking interface. A 3D view offers interactive visualization techniques to gain deeper insight, e.g., into the aggregated quality of the examined fiber reconstruction algorithms and parameterizations. The tool was designed in close collaboration with researchers who work with fiber‐reinforced polymers on a daily basis and develop algorithms for tomographic reconstruction and characterization of such materials. We evaluate the tool using synthetic datasets as well as tomograms of real materials. Five case studies certify the usefulness of the tool, showing that it significantly accelerates the analysis and provides valuable insights that make it possible to improve the fiber reconstruction algorithms. The main contribution of the paper is the well‐considered combination of methods and their seamless integration into a visual tool that supports the entire workflow. Further findings result from the analysis of (dis‐)similarity measures for fibers as well as from the discussion of design decisions. It is also shown that the generality of the analytical methods allows a wider range of applications, such as the application in pore space analysis.