Dense dislocation walls and microbands aligned with slip planes-theoretical considerations

Some of the dislocation boundaries in cold deformed f.c.c. metals at low and intermediate strains lie on crystallographic slip planes and others have a macroscopic direction with respect to the sample axes (i.e. they are non-crystallographic). A model for the occurrence of the former type of dislocation boundaries is proposed. The model combines slip pattern analysis and dislocation theory. It is assumed (i) that the dislocations in the boundaries are generated by slip, (ii) that the deformation temperature is low enough to exclude dislocation climb and (iii) that the driving force for formation of boundaries is minimisation of the energy stored in the boundaries. Formation of crystallographic boundaries is predicted if two active slip systems in the same slip plane account for a large fraction of the total slip. For single crystals the agreement between predicted and experimentally observed crystallographic and non-crystallographic boundaries is excellent. For different grain orientation in poly crystalline aluminium specimens, the agreement between prediction and experiment is satisfactory in view of the complexity of polycrystal studies compared to studies of single crystals.     

Effect of Grain Boundaries and Grain Orientation on Structure and Properties

The evolution of deformation microstructures in metals follows a universal pattern of grain subdivision. However, the structure in the grain boundary region may be different from that in the grain interior, although a characteristic region cannot be identified for polycrystals with medium to high stacking fault energy. In the grain interior, the dislocation structure is predominantly composed of almost planar boundaries (geometrically necessary boundaries) and cell boundaries (incidental dislocation boundaries) forming a cell block structure. For grains with grain sizes reaching down to about 4 μm deformed in tension and by rolling, a clear correlation has been established between the characteristics of the deformation structure and the orientation of the grain in which it evolves. A similar correlation is observed for single crystals of different orientations. Such correlations form the basis for a general analysis of active slip systems and for modeling of the flow stress and flow stress anisotropy of polycrystalline samples.     

A botanical compound, Padma 28, increases walking distance in stable intermittent claudication

Thirty-six patients with a median age of sixty-seven years and a median duration of intermittent claudication of five years were randomized to either active treatment with Padma 28 or placebo. The effect of treatment was quantified by measurements of systemic and peripheral systolic blood pressures and by measurements of the pain-free and the maximal walking distance on a treadmill. The ankle pressure index (ankle systolic pressure/arm systolic pressure) was calculated. The group randomized to active treatment received two tablets bid containing 340 mg of a dried herbal mixture composed according to an ancient lamaistic preparation (Padma 28). After active treatments, administered over a period of four months in a double-blinded, randomized design, the patients allocated to this group attained a significant increase in the pain-free walking distance from 52 m (20-106) to 86 m (24-164; P < 0.05) and in the maximal walking distance from 115 m (72-218) to 227 m (73- > 1,000; P < 0.05). The patient-group receiving placebo treatments did not show any significant changes in either the painfree or the maximal walking distance. The authors could not demonstrate any significant changes in the ankle pressure index either during active or during placebo treatment. In conclusion, this study has shown that treatment with Padma 28 over a period of four months significantly increased the walking distance in patients with stable, intermittent claudication of long duration.     

High-efficiency retrovirus-mediated gene transfer into the livers of mice

Recombinant retroviral vectors represent an attractive means of transferring genes into the liver because they integrate in the host cell genome and result in permanent gene expression. However, efficient gene transfer is limited by the requirement of active cell division for integration. Surgical partial hepatectomy has been the traditional method of inducing hepatocellular proliferation, but this invasive approach would be difficult to justify in clinical gene therapy. As an alternative, we used a recombinant adenovirus expressing a nonsecreted form of urokinase plaminogen activator (Ad.PGKmuPA), which results in liver regeneration over a period of 8 days. When a high-titer retroviral vector was continuously infused into the portal vein of mice during this period of hepatocyte proliferation, 33.5% of hepatocytes were stably transduced. In addition, high-level expression of a secreted transgene reporter was sustained for at least 48 weeks (length of experiment). We investigated the influence of vector titer on the in vivo transduction efficiency in our system, and found that the total number of infectious retroviral particles delivered per target cell is a critical factor. The results presented here demonstrate the ability to obtain a high gene transfer efficiency and long-term gene expression in hepatocytes in vivo without the need for surgical hepatectomy. The two-vector system described here may be of clinical relevance, as the level of hepatic gene transfer achieved has potential to be curative for a large number of genetic liver diseases.     

Neurologic disease among women with breast implants

US angiography, enhanced with intraarterial CO2 microbubbles imaging, documented 40 nodules of hepatocellular carcinoma (HCC) lesser than 20 mm in diameter in 34 patients, which were convinced histopathologically. As to the imaging acuity of arterial vascularity in nodules, US angiography was compared with DSA and US color angio. The detection of arterial vascularity was possible in 34 (85.0%) of 40 nodules by US angiography, 26 (65.0%) by DSA, and 28 (70.0 %) by US color angio. US angiography was available for detection of HCC, particularly with small HCC lesser than 20 mm in size.     

Matching policy and people? Household responses to the promotion of renewable electricity

In this paper, we study the responses among households to the promotion of renewable electricity. We analyse an experiment conducted by a Norwegian power company that offered Guarantees of Origin of supply to 5,000 of their customers. In the experiment, five different groups of 1,000 customers each received information about a renewable electricity certificate and how to purchase it. The information and the reasons given for why the customers should accept the offer was framed differently to each of the groups. The experiment produced minimal responses, and we use material from focus group discussions and in-depth interviews for interpreting and explaining the results. The analysis shows that customers tend to disregard information coming from their supplier, while there is also a low degree of commensurability between the message presented in the information and the understandings and perceptions held by the customers. For example, whereas the information contained the argument that customers must purchase certificates to obtain renewable electricity, Norwegians, because of their awareness of the country’s hydro-based production system, perceive electricity to be renewable as it is. Additionally, focus group participants found the presented terms and figures to be incomprehensible to the extent that the information can be said to have produced ignorance in them. In turn, this negatively affected people’s trust in the message and also its sender, as relevance and reliability are disclosure’s main challenges in Norway. We use the case of electricity labelling in Norway to demonstrate some of the general challenges associated with using information as a tool for changing people’s consumption patterns in deregulated energy markets.     

Sustainable controlling of hydrophilic properties of cotton and linen by application of amino acids

Three different hydrophobic amino acids (valine, leucine, and phenylalanine) are used in wet-finishing application on natural fiber fabrics from cotton and linen. By this application, a decrease in hydrophilic properties of the fabrics can be determined by two analytical methods (capillary rise test and TEGEWA drop test) – with most significant results after application of valine or leucine. By this simple approach, the proof of concept is done that small and natural based molecules can be used for an eco-friendly modification of natural fibers. This could be a promising starting point for further development of eco-friendly finishing agents.