Hydrogen sieving and storage in fullerene intercalated graphite

The geometrical properties of recently synthesised C60 intercalated in graphite have been confirmed by density-functional-based computer simulations. The capability of this material to store molecular hydrogen by physisorption is evaluated. While the material can sieve H2 from heavier molecular gases, our free energy calculations indicate that further tuning of the system by reducing the amount of intercalated fullerene cages is necessary to achieve H2 loadings which are interesting for technical applications.     

Toward atomic-scale bright-field electron tomography for the study of fullerene-like nanostructures

We present the advancement of electron tomography for three-dimensional structure reconstruction of fullerene-like particles toward atomic-scale resolution. The three-dimensional reconstruction of nested molybdenum disulfide nanooctahedra is achieved by the combination of low voltage operation of the electron microscope with aberration-corrected phase contrast imaging. The method enables the study of defects and irregularities in the three-dimensional structure of individual fullerene-like particles on the scale of 2-3 A. Control over shape, size, and atomic architecture is a key issue in synthesis and design of functional nanoparticles. Transmission electron microscopy (TEM) is the primary technique to characterize materials down to the atomic level, albeit the images are two-dimensional projections of the studied objects. Recent advancements in aberration-corrected TEM have demonstrated single atom sensitivity for light elements at sub?ngstr?m resolution. Yet, the resolution of tomographic schemes for three-dimensional structure reconstruction has not surpassed 1 nm3, preventing it from becoming a powerful tool for characterization in the physical sciences on the atomic scale. Here we demonstrate that negative spherical aberration imaging at low acceleration voltage enables tomography down to the atomic scale at reduced radiation damage. First experimental data on the three-dimensional reconstruction of nested molybdenum disulfide nanooctahedra is presented. The method is applicable to the analysis of the atomic architecture of a wide range of nanostructures where strong electron channeling is absent, in particular to carbon fullerenes and inorganic fullerenes.     

Wear, Plasticity, and Rehybridization in Tetrahedral Amorphous Carbon

Wear in self-mated tetrahedral amorphous carbon (ta-C) films is studied by molecular dynamics and near-edge X-ray absorption fine structure spectroscopy. Both theory and experiment demonstrate the formation of a soft amorphous carbon (a-C) layer with increased sp² content, which grows faster than an a-C tribolayer found on self-mated diamond sliding under similar conditions. The faster $\hbox{sp}^{3} \rightarrow\,\hbox{ sp}^{2}$ transition in ta-C is explained by easy breaking of prestressed bonds in a finite, nanoscale ta-C region, whereas diamond amorphization occurs at an atomically sharp interface. A detailed analysis of the underlying rehybridization mechanism reveals that the $\hbox{sp}^{3}\, \rightarrow\hbox{ sp}^{2}$ transition is triggered by plasticity in the adjacent a-C. Rehybridization therefore occurs in a region that has not yet experienced plastic yield. The resulting soft a-C tribolayer is interpreted as a precursor to the experimentally observed wear.     

A statistical model and simulator for cardiovascular pressure signals

Physiological signal simulators are often used to conduct validation studies of commercially available devices such as oscillometric non-invasive blood pressure (NIBP) monitors. Numerous assessment studies have been conducted using simulators to validate commercial NIBP monitors. While there are several simulators commercially available to evaluate oscillometric NIBP devices, currently there are no simulators designed to validate invasive pressure signal devices. A statistical model and simulator for invasive cardiovascular pressure signals such as arterial blood pressure and intracranial pressure are described. The model incorporates the effects of respiration on pressure signals and can be used to generate synthetic signals with time and frequency domain characteristics matching any desired subject population. Additionally, the way that noise and artefacts typically present in real pressure signals should be modelled is described. The proposed statistical model is a useful tool for validation of algorithms designed to process or analyse biomedical pressure signals to estimate parameters of clinical interest such as the cardiac frequency, heart rate variability, respiratory frequency, and pulse pressure variation in the presence of noise. The model can be used to simulate signals in order to validate commercial devices that process and analyse invasive pressure signals.     

Natural Numbers in Trans-classic Systems

PART I

Mathematico-Philosophical Prolegomena

Part II of this essay was written before Part I and offered to the Third Annual Symposium of the American Society for Cybernetics as a topic of discussion. However, owing to unforeseen circumstances, the paper was not presented at the Symposium. This turned out to be a blessing in disguise. In order to conform to the time limit for oral presentation Part II was written in a highly condensed manner and there was no opportunity to elaborate on the general epistemological aspect which served as the starting point for the intended confrontation between natural numbers and structural systems of higher complexity than our traditional logic offers. We are determined to make up for this omission in Part I because we believe that the theoretical goal of Part II will be better understood if the present author clarifies his attitude toward the basic concept of organism and its mathematical treatment in cybernetic research.     

A fibroadenoma with a t(4;12) (q27;q15) affecting the HMGI-C gene, a member of the high mobility group protein gene family

The tumor-initiating activities of the methanol extracts of polyetherurethanes (PEUs) were first detected in the presence of 12-0-tetradecanyl-phorbol-13-acetate (TPA) using Balb 3T3 transformation assay. A model hard segment of PEUs, 4,4'-di(ethoxycarboamide) diphenylmethane (MDU), showed initiating activity, while chemical moieties other than the hard segment were shown to be negative in the test. The transformation assay was carried out using glass dishes half coated with two different PEUs, PU4 and PU8. In the presence of TPA, the transforming activities correlated with the tumorigenic potential in the rat implantation study on the coated surface of PEUs, but not on the uncoated glass area. From these results it was concluded that initiation was caused by the hard-segment moiety such as MDU structure derived not only from the leachable extracts but also from the biodegradable substances by the direct interaction of cells with the coated materials.     

The Jacalin-Related Lectin HvHorcH Is Involved in the Physiological Response of Barley Roots to Salt Stress

Salt stress tolerance of crop plants is a trait with increasing value for future food production. In an attempt to identify proteins that participate in the salt stress response of barley, we have used a cDNA library from salt-stressed seedling roots of the relatively salt-stress-tolerant cv. Morex for the transfection of a salt-stress-sensitive yeast strain (Saccharomyces cerevisiae YSH818 Δhog1 mutant). From the retrieved cDNA sequences conferring salt tolerance to the yeast mutant, eleven contained the coding sequence of a jacalin-related lectin (JRL) that shows homology to the previously identified JRL horcolin from barley coleoptiles that we therefore named the gene HvHorcH. The detection of HvHorcH protein in root extracellular fluid suggests a secretion under stress conditions. Furthermore, HvHorcH exhibited specificity towards mannose. Protein abundance of HvHorcH in roots of salt-sensitive or salt-tolerant barley cultivars were not trait-specific to salinity treatment, but protein levels increased in response to the treatment, particularly in the root tip. Expression of HvHorcH in Arabidopsis thaliana root tips increased salt tolerance. Hence, we conclude that this protein is involved in the adaptation of plants to salinity.     

In response to "Up with our foremothers."

Comments on M. D. Bernstein and N. F. Russo's (see record 1974-24228-001) reflection on the status of women's authorship in the field of psychology. Staats relates her personal experience, which differed significantly from the situation described by Bernstein and Russo in which women authors do not receive proper credit for their work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Die Isolierung der Sulfide aus unlegierten Stählen

Möglichkeiten zur Sulfidisolierung. Isolierung durch elektrolytische Auflösung der Stahlmatrix. Fehlerquellen durch leichte Oxidierbarkeit von Mangansulfid und Verlust kleinster Teilchen. Arbeitsvorschrift zur quantitativen elektrolytischen Isolierung und Sammlung der Isolate. Untersuchung der Sulfidzusammensetzung.