Towards an Evaluation Framework for Threat Intelligence Sharing Platforms

Threat intelligence sharing is an important countermeasure against the increasing number of security threats to which companies and governments are exposed. Its objective is the cross-organizational exchange of information about actual and potential threats. In recent years, a heterogeneous market of threat intelligence sharing platforms (TISPs) has emerged. These platforms are inter-organizational systems that support collaborative collection, aggregation, analysis and dissemination of threat-related information. Organizations that consider using TISPs are often faced with the challenge of selecting suitable platforms. To facilitate the evaluation of threat intelligence sharing platforms, we present a framework for analyzing and comparing relevant TISPs. Our framework provides a set of 25 functional and non-functional criteria that support potential users in selecting suitable platforms. We demonstrate the applicability of our evaluation framework by assessing three platforms: MISP, OTX and ThreatQ. We describe common features and differences between the three platforms

The Discovery of Nonpeptide Endothelin Receptor Antagonists. Progression towards Bosentan

Since its discovery, endothelin-1 has attracted considerable scientific interest for its extremely potent and long-lasting vasoconstrictor effect and its binding to G-protein-coupled receptors. The endothelins appear to be part of a functional regulatory system in the circulation and strong evidence has accumulated for their involvement in clinical disorders associated with vasoconstriction (e.g. renal failure, congestive heart failure).In a program aimed at identifying nonpeptide ET receptor antagonists, a distinct class of substituted arylsulfonamido pyrimidines was discovered from a chemical substance library. Lead optimization led to orally active antagonists of ETA and ETB receptors possessing mixed or receptor-subtype-selective profiles in the low nanomolar range. From these compounds, the mixed antagonist bosentan was selected for development; it shows efficacy in several pathophysiological models of local and systemic vasoconstriction and promising clinical results in patients suffering from congestive heart failure.Chemical modifications in this structural class in combination with X-ray crystal data analysis for key compounds led to more in-depth understanding of antagonist-receptor interaction. Structural determinants of bosentan binding to the ETA receptor were defined on the molecular level by site-directed mutagenesis experiments. This led to a 3D model of the antagonist binding domain which proved valuable to rationalize structure-activity relationships

Patterned Electrode Assisted One-Step Fabrication of Biomimetic Morphing Hydrogels with Sophisticated Anisotropic Structures

Anisotropic structures are ubiquitous in nature, affording fascinating morphing behaviors. Biomimetic morphing materials can be developed by spatially controlling the orientations of molecules or nanofillers that produce anisotropic responses and internal stresses under external stimuli. However, it remains a serious challenge to fabricate materials with sophisticated anisotropic architectures. Here, a facile strategy to fabricate morphing hydrogels with elaborately ordered structures of nanosheets, which are oriented under distributed electric field and immobilized by polymerization to form a poly(N‐isopropylacrylamide) matrix, is proposed. Diverse sophisticated anisotropic structures are obtained by engineering the electric field through the patterns and relative locations of the electrodes. Upon heating, the monolithic hydrogels with through‐thickness and/or in‐plane gradients in orientation of the nanosheets deform into various three‐dimensional configurations. After incorporating gold nanoparticles, the hydrogels become photoresponsive and capable of programmable motions, for example, dynamic twisting and flipping under spatiotemporal stimuli. Such a strategy of using patterned electrodes to generate distributed electric field should be applicable to systems of liquid crystals or charged particles/molecules to direct orientation or electrophoresis and form functional structures. The biomimetically architectured hydrogels would be ideal materials to develop artificial muscles, soft actuators/robots, and biomedical devices with versatile applications

Terrestrial solar radiation driven photodecomposition of ciprofloxacin in clinical wastewater applying mesostructured iron(III) oxide

Cationic cylindrical polymer brushes based on polybutadiene-block-poly(2-vinylpyridine) were applied as structure-directing agent for mesostructuring F

Selective Adsorption and Chiral Amplification of Amino Acids in Vermiculite Clay -Implications for the origin of biochirality

Smectite clays are hydrated layer silicates that, like micas, occur naturally in abundance. Importantly, they have readily modifiable interlayer spaces that provide excellent sites for nanochemistry. Vermiculite is one such smectite clay and in the presence of small chain-length alkyl-NH3Cl ions, forms sensitive, 1-D ordered model clay systems with expandable nano-pore inter-layer regions. These inter-layers readily adsorb organic molecules. N-propyl NH3Cl vermiculite clay gels were used to determine the adsorption of alanine, lysine and histidine by chiral HPLC. The results show that during reaction with fresh vermiculite interlayers, significant chiral enrichment of either L- and D-enantiomers occurs depending on the amino acid. Chiral enrichment of the supernatant solutions is up to about 1% per pass. In contrast, addition to clay interlayers already reacted with amino acid solutions resulted in little or no change in D/L ratio during the time of the experiment. Adsorption of small amounts of amphiphilic organic molecules in clay inter-layers is known to produce Layer-by-Layer or Langmuir-Blodgett films. Moreover atomistic simulations show that self-organization of organic species in clay interlayers is important. These non-centrosymmetric, chirally active nanofilms may cause clays to act subsequently as chiral amplifiers, concentrating organic material from dilute solution and having different adsorption energetics for D- and L-enantiomers. The additional role of clays in RNA oligimerization already postulated by Ferris and others, together with the need for the organization of amphiphilic molecules and lipids noted by Szostak and others, suggests that such chiral separation by clays in lagoonal environments at normal biological temperatures might also have played a significant role in the origin of biochirality.Comment: 17 Pages, 2 Figures, 4 Table

The molybdenum isotopic composition of the modern ocean

Natural variations in the isotopic composition of molybdenum (Mo) are showing increasing potential as a tool in geochemistry. Although the ocean is an important reservoir of Mo, data on the isotopic composition of Mo in seawater are scarce. We have recently developed a new method for the precise determination of Mo isotope ratios on the basis of preconcentration using a chelating resin and measurement by multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), which allows us to measure every stable Mo isotope. In this study, 172 seawater samples obtained from 9 stations in the Pacific, Atlantic, and Southern Oceans were analyzed, giving global coverage and the first full depth-profiles. The average isotope composition in δA/95Mo (relative to a Johnson Matthey Mo standard solution) was as follows: δ92/95Mo = –2.54 ± 0.16‰ (2SD), δ94/95Mo = –0.73 ± 0.19‰, δ96/95Mo = 0.85 ± 0.07‰, δ97/95Mo = 1.68 ± 0.08‰, δ98/95Mo = 2.48 ± 0.10‰, and δ100/95Mo = 4.07 ± 0.18‰. The δ values showed an excellent linear correlation with atomic mass of AMo (R2 = 0.999). Three-isotope plots for the Mo isotopes were fitted with straight lines whose slopes agreed with theoretical values for mass-dependent isotope fractionation. These results demonstrate that Mo isotopes are both uniformly distributed and follow a mass-dependent fractionation law in the modern oxic ocean. A common Mo standard is urgently required for the precise comparison of Mo isotopic compositions measured in different laboratories. On the other hand, our results strongly support the possibility of seawater as an international reference material for Mo isotopic composition