New graphic representation of structural parameters of proteins

A computer program is described that is designed to make the visual inspection of classical plots of protein properties (e.g. hydrophobicity, volume, etc.) as a function of sequence easier. An algorithm written in BASIC language has been used in order to generate a pseudo-tridimensional representation of the desired protein property. The data utilized by the program are arithmetic averages of the selected parameter obtained by using a five-residue window as a shuttle along the given amino acid sequence.     

Mercury adsorption by montmorillonite and vermiculite: a combined XRD, TG-MS, and EXAFS study

Synchrotron-based extended X-ray absorption fine structure spectroscopy (EXAFS), X-ray diffraction at room and high temperature, thermal analyses combined with mass spectrometry of evolved gas, and chemical analyses contributed to assess the influence of mercury on montmorillonite and vermiculite layers.The adsorbed Hg amount was higher for montmorillonite (Hg=37.7 meq/100 g) than for vermiculite (Hg=28.0 meq/100 g). The basal spacing for the Hg treated samples was 15.2 (montmorillonite) and 14.5 Å (vermiculite). Thermal and evolved gas spectrometry analyses suggest that Hg was released at T230 °C and at 600 °C for montmorillonite, but at 550, 800 and 860 °C for vermiculite.The effect of temperature on Hg release is also apparent when the basal spacing at 230 °C for montmorillonite (d₀₀₁=10.3 Å) is compared to that for vermiculite (d₀₀₁=11.8 Å).EXAFS analyses provide qualitative evidence that oxygen atoms occupy the first coordination shell of Hg in both clay minerals. The best fit between observed and calculated spectra is obtained when montroydite is assumed as a reference model compound.     

Identification of a beta-lactoglobulin lactosylation site

In various animal models of cerebral hypoxia-ischemia, it is not clear whether neuronal apoptosis results from hypoxia alone or whether other factors mediate this process. We hypothesized that (1) hypoxia alone can induce neuronal apoptosis, (2) hypoxic severity alters the time course of neuronal apoptosis, (3) hypoxia increases neuronal p53, and this increase in p53 is critical for neuronal apoptosis. Embryonic neocortical neurons cultured for 7-10 days were placed in an incubator with levels set at 0.1%, 1%, and 3% O2 and were removed at 24-h intervals for study. Under all hypoxic conditions, observed changes in cellular morphology and DNA fragmentation, detected by the TUNEL method and gel electrophoresis, were consistent with apoptosis. These alterations were seen after a shorter period with increasing hypoxic severity. Immunoblot analysis revealed an increase in p53 protein in hypoxia-exposed neurons. Analysis of immunofluorescence-stained neurons revealed increases in p53 with increased duration and severity of hypoxia. Antisense oligonucleotides for p53 significantly increased the number of surviving neurons during hypoxic exposure. We conclude that hypoxia-induced neuronal apoptosis is, in part, a p53-dependent process whose time course is influenced by hypoxic severity and duration.     

Real-time processing of serial stimuli in classical conditioning of the rabbit's nictitating membrane response.

Real-time models contend that a CS gives rise to a cascade of hypothetical stimuli that govern CRs on a moment-to-moment basis. Experiments with the rabbit nictitating membrane response successfully extended these models to external stimuli. CRs were trained in sequence with an unconditioned stimulus/stimuli (UCS) (CSA–CSB–UCS). When the CSA–CSB interval was shortened, the CR was compressed; when the CSA–CSB interval was lengthened, the CR was broadened. Peaks appeared at 2 places, namely, one following CSA by a period equal to the CS–UCS interval and another following CSB by its CS–UCS interval. Outside the sequence, the individual CSs evoked CRs located between their respective CS–UCS intervals. When, however, the 2 CSs were trained separately, the CRs were appropriate to their respective CS–UCS intervals when tested alone or in sequence. The results are discussed in terms of the J. E. Desmond and J. W. Moore (1988) and S. Grossberg and N. A. Schmajuk (1989) models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chelating polymeric particles intended for the therapy of Wilson’s disease

Wilson’s disease is a genetic disorder that leads to a high accumulation of copper in multiple organs with subsequent toxic effects. In this paper, a gentle therapy to eliminate harmful copper concentrations in patients with Wilson’s disease is proposed using an oral administration of insoluble polymeric sorbents containing selective chelating groups for copper(II). The sorbents contained triethylenetetramine, N,N-di(2-pyridylmethyl)amine, 8-hydroxyquinoline or 8-hydroxyquinoline-5-sulfonic acid chelating groups bound to a methacrylate-based macroporous support. Nearly quantitative copper(II) uptake within minutes was achieved in buffers modeling the pH range present in the gastric environment (pH 2.0 and 4.0). The sorbents demonstrated chelating selectivity for copper(II) against zinc(II) with ratios of up to 1321. The sorbents demonstrated sufficient stability of the copper complexes against rechelation using studies in a model environment for the small intestine (the presence of chelating amino acids, pH 6.8).     

Two 2D postprocessing tools and their applications to the improvement of 3D pictures

When displaying abstract objects, as in the case of scientific visualization, it is manadatory to give the user a maximum of cues to help him understand the displayed structures. In this short note, we describe two general, simple 2D postprocessing tools and their applications for the improvement of 3D perception by means of simulation of realistic 3D effects.     

Preparation of metal‐containing protein fibers and their antimicrobial properties

Bombyx mori silk, Antheraea pernyi silk, and wool fibers were chemically modified by treatment with tannic acid (TA) or by acylation with ethylenediaminetetraacetic (EDTA) dianhydride. Kinetics of TA loading or acylation with EDTA‐dianhydride varied from fiber to fiber. B. mori silk and wool displayed the highest weight gains with TA and EDTA‐dianhydride, respectively. The uptake of different metal ions (Ag⁺, Cu²⁺, Co²⁺) by protein fibers, either untreated or chemically modified, was studied as a function of weight gain and pH of the aqueous metal solution. Below pH 7, absorption of metal ions by untreated and TA‐treated fibers was negligible. Acylation with EDTA‐dianhydride enabled protein fibers to absorb and bind significant amounts of metal ions in the acidic and neutral pH range. The levels of metal desorption at acidic pH depended on the fiber‐metal combination. Untreated protein fibers usually displayed the lowest stability of the metal complex. Metal complexes with protein fibers exhibited prominent antimicrobial activity against the plant pathogen Cornebacterium. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 638–644, 2003     

Share with strangers: Privacy bubbles as user-centered privacy control for mobile content sharing applications

A continually increasing number of pictures and videos is shared in online social networks. Current sharing platforms, however, only offer limited options to define who has access to the content. Users may either share it with individuals or groups from their social graph, or make it available to the general public. Sharing content with users to which no social ties exist, even if they were physically close to the places where content was created and witnessed the same event, is however not supported by most existing platforms. We thus propose a novel approach to share content with such users based on so-called privacy bubbles. Privacy bubbles metaphorically represent the private sphere of the users and automatically confine the access to the content generated by the bubble creator to people within the bubble. Bubbles extend in both time and space, centered around the collection time and place, and their size can be adapted to the user's preferences. We confirm the user acceptance of our concept through a questionnaire-based study with 175 participants, and a prototype implementation shows the technical feasibility of our scheme.