109 research outputs found

    New Wet White/Chrome Free Process offering significant Environmental and Physical Property advantages from Beamhouse to Crust

    Get PDF
    Content: A combination of processing techniques and speciality chemicals has been developed to target environmental issues and legislation in the European leather industry, especially for automotive upholstery leather. This process combines new techniques in the beamhouse process through to the tanning process. Initial work on several different individual concepts showed some excellent improvements, but when these concepts have been brought together to form a single strategic process the advantages and improvements have exceeded expectations. The process demonstrates a reduction in the use of salt, formic acid and sulphuric acid. After more than two years of trials from small scale to full production in an automotive leather production environment, we are able to present independently test results showing the benefits of following this system. Briefly these include Improvement in tear and tensile strength results. Improved clarification with less suspended solids in the supernatant. Reduced COD in the supernatant and higher biodegradability COD/BOD. Less TDS in the supernatant. Chloride content reduction in the supernatant Sludge generation reduction. Less organic residues derived from the hide. Take-Away: A simple technique and small modifications to existing processing methods will reduce dramatically the environmental effects of wet white / chrome free tanning. This process can be used in any country in the world and answers many questions regarding reducing salt, BOD, COD, TDS etc

    Optimized network structure and routing metric in wireless multihop ad hoc communication

    Full text link
    Inspired by the Statistical Physics of complex networks, wireless multihop ad hoc communication networks are considered in abstracted form. Since such engineered networks are able to modify their structure via topology control, we search for optimized network structures, which maximize the end-to-end throughput performance. A modified version of betweenness centrality is introduced and shown to be very relevant for the respective modeling. The calculated optimized network structures lead to a significant increase of the end-to-end throughput. The discussion of the resulting structural properties reveals that it will be almost impossible to construct these optimized topologies in a technologically efficient distributive manner. However, the modified betweenness centrality also allows to propose a new routing metric for the end-to-end communication traffic. This approach leads to an even larger increase of throughput capacity and is easily implementable in a technologically relevant manner.Comment: 25 pages, v2: fixed one small typo in the 'authors' fiel

    Tetramerization of BEB-Doped Phenalenyls to Obtain (BE)<sub>8</sub>-[16]Annulenes (E = N, O)

    Get PDF
    Two (BE)8-[16]annulenes were prepared and fully characterized by experimental and quantum-chemical means (1, E = N; 2, E = O). The 1,8-naphthalenediyl-bridged diborane(6) 3 served as their common starting material, which was treated with [Al(NH3)6]Cl3 to form 1 (91% yield) or with 1,8-naphthalenediboronic acid anhydride to form 2 (93% yield). As a result, the heteroannulenes 1 and 2 are supported by four aromatic “clamps” and may also be viewed as NH- or O-bridged cyclic tetramers of BNB- or BOB-doped phenalenyls. X-ray crystallography on mono-, di-, and tetraadducts 2·thf, 2·py2, and 2·py4 showed that 2 is an oligotopic Lewis acid (thf/py: tetrahydrofuran/pyridine donor). The applicability of 2 also as a Lewis basic ligand in coordination chemistry was demonstrated by the synthesis of the mononuclear Ag+ complex [Ag(py)2(2·py4)]+ and the dinuclear Pb2+ complex 6. During the assembly of 6, the rearrangement of 2 led to the formation of two (BO)9-macrocycles linked by two BOB-phenalenyls to form a nanometer-sized cage with four negatively charged, tetracoordinated B atoms. Both 1 and 2 show several redox waves in the cathodic regions of the cyclic voltammograms. An in-depth assessment of the consequences of electron injection on the aromaticity of 1 and 2 was achieved by electronic structure calculations. 1 and 2 are proposed to exhibit aromatic switching capabilities in the [16]annulene motif.</p

    Differential phenotyping of Brucella species using a newly developed semi-automated metabolic system

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>A commercial biotyping system (Taxa Profileℱ, Merlin Diagnostika) testing the metabolization of various substrates by bacteria was used to determine if a set of phenotypic features will allow the identification of members of the genus <it>Brucella </it>and their differentiation into species and biovars.</p> <p>Results</p> <p>A total of 191 different amines, amides, amino acids, other organic acids and heterocyclic and aromatic substrates (Taxa Profileℱ A), 191 different mono-, di-, tri- and polysaccharides and sugar derivates (Taxa Profileℱ C) and 95 amino peptidase- and protease-reactions, 76 glycosidase-, phosphatase- and other esterase-reactions, and 17 classic reactions (Taxa Profileℱ E) were tested with the 23 reference strains representing the currently known species and biovars of <it>Brucella </it>and a collection of 60 field isolates. Based on specific and stable reactions a 96-well "<it>Brucella </it>identification and typing" plate (Micronautℱ) was designed and re-tested in 113 <it>Brucella </it>isolates and a couple of closely related bacteria.</p> <p><it>Brucella </it>species and biovars revealed characteristic metabolic profiles and each strain showed an individual pattern. Due to their typical metabolic profiles a differentiation of <it>Brucella </it>isolates to the species level could be achieved. The separation of <it>B. canis </it>from <it>B. suis </it>bv 3, however, failed. At the biovar level, <it>B. abortus </it>bv 4, 5, 7 and <it>B. suis </it>bv 1-5 could be discriminated with a specificity of 100%. <it>B. melitensis </it>isolates clustered in a very homogenous group and could not be resolved according to their assigned biovars.</p> <p>Conclusions</p> <p>The comprehensive testing of metabolic activity allows cluster analysis within the genus <it>Brucella</it>. The biotyping system developed for the identification of <it>Brucella </it>and differentiation of its species and biovars may replace or at least complement time-consuming tube testing especially in case of atypical strains. An easy to handle identification software facilitates the applicability of the Micronautℱ system for microbiology laboratories.</p

    Boolean Delay Equations: A simple way of looking at complex systems

    Full text link
    Boolean Delay Equations (BDEs) are semi-discrete dynamical models with Boolean-valued variables that evolve in continuous time. Systems of BDEs can be classified into conservative or dissipative, in a manner that parallels the classification of ordinary or partial differential equations. Solutions to certain conservative BDEs exhibit growth of complexity in time. They represent therewith metaphors for biological evolution or human history. Dissipative BDEs are structurally stable and exhibit multiple equilibria and limit cycles, as well as more complex, fractal solution sets, such as Devil's staircases and ``fractal sunbursts``. All known solutions of dissipative BDEs have stationary variance. BDE systems of this type, both free and forced, have been used as highly idealized models of climate change on interannual, interdecadal and paleoclimatic time scales. BDEs are also being used as flexible, highly efficient models of colliding cascades in earthquake modeling and prediction, as well as in genetics. In this paper we review the theory of systems of BDEs and illustrate their applications to climatic and solid earth problems. The former have used small systems of BDEs, while the latter have used large networks of BDEs. We moreover introduce BDEs with an infinite number of variables distributed in space (``partial BDEs``) and discuss connections with other types of dynamical systems, including cellular automata and Boolean networks. This research-and-review paper concludes with a set of open questions.Comment: Latex, 67 pages with 15 eps figures. Revised version, in particular the discussion on partial BDEs is updated and enlarge

    Extracorporeal immune therapy with immobilized agonistic anti-Fas antibodies leads to transient reduction of circulating neutrophil numbers and limits tissue damage after hemorrhagic shock/resuscitation in a porcine model

    Get PDF
    Background: Hemorrhagic shock/resuscitation is associated with aberrant neutrophil activation and organ failure. This experimental porcine study was done to evaluate the effects of Fas-directed extracorporeal immune therapy with a leukocyte inhibition module (LIM) on hemodynamics, neutrophil tissue infiltration, and tissue damage after hemorrhagic shock/resuscitation. Methods: In a prospective controlled double-armed animal trial 24 Munich Mini Pigs (30.3 +/- 3.3 kg) were rapidly haemorrhaged to reach a mean arterial pressure (MAP) of 35 +/- 5 mmHg, maintained hypotensive for 45 minutes, and then were resuscitated with Ringer's solution to baseline MAP. With beginning of resuscitation 12 pigs underwent extracorporeal immune therapy for 3 hours (LIM group) and 12 pigs were resuscitated according to standard medical care (SMC). Haemodynamics, haematologic, metabolic, and organ specific damage parameters were monitored. Neutrophil infiltration was analyzed histologically after 48 and 72 hours. Lipid peroxidation, and apoptosis were specifically determined in lung, bowel, and liver. Results: In the LIM group, neutrophil counts were reduced versus SMC during extracorporeal immune therapy. After 72 hours, the haemodynamic parameters MAP and cardiac output (CO) were significantly better in the LIM group. Histological analyses showed reduction of shock-related neutrophil tissue infiltration in the LIM group, especially in the lungs. Lower amounts of apoptotic cells and lipid peroxidation were found in organs after LIM treatment. Conclusions: Transient Fas-directed extracorporeal immune therapy may protect from posthemorrhagic neutrophil tissue infiltration and tissue damage

    Munigua, Spanien

    Get PDF
    Since more than 60 years the Madrid Department of the German Archaeological Institute has been conducting investigations at the Hispano-Roman municipium of Munigua. Current research focuses on a 3D-visualisation and reconstruction of the city. The project is accompanied by a thorough study of the function and use of the individual buildings in antiquity. During the campaigns of 2015 and 2016 the forum, the streets as well as the podium-temple of the city were analyzed. As a result, the voting process on the forum as well as the processional way through the city could be hypothetically reconstructed. A geophysical survey in the southern part of the city revealed the existence and structure of buildings

    Cellular Adhesion Gene SELP Is Associated with Rheumatoid Arthritis and Displays Differential Allelic Expression.

    Get PDF
    In rheumatoid arthritis (RA), a key event is infiltration of inflammatory immune cells into the synovial lining, possibly aggravated by dysregulation of cellular adhesion molecules. Therefore, single nucleotide polymorphisms of 14 genes involved in cellular adhesion processes (CAST, ITGA4, ITGB1, ITGB2, PECAM1, PTEN, PTPN11, PTPRC, PXN, SELE, SELP, SRC, TYK2, and VCAM1) were analyzed for association with RA. Association analysis was performed consecutively in three European RA family sample groups (Nfamilies = 407). Additionally, we investigated differential allelic expression, a possible functional consequence of genetic variants. SELP (selectin P, CD62P) SNP-allele rs6136-T was associated with risk for RA in two RA family sample groups as well as in global analysis of all three groups (ptotal = 0.003). This allele was also expressed preferentially (p<10-6) with a two- fold average increase in regulated samples. Differential expression is supported by data from Genevar MuTHER (p1 = 0.004; p2 = 0.0177). Evidence for influence of rs6136 on transcription factor binding was also found in silico and in public datasets reporting in vitro data. In summary, we found SELP rs6136-T to be associated with RA and with increased expression of SELP mRNA. SELP is located on the surface of endothelial cells and crucial for recruitment, adhesion, and migration of inflammatory cells into the joint. Genetically determined increased SELP expression levels might thus be a novel additional risk factor for RA
    • 

    corecore