Monoclinic sphere packings. I. Invariant, univariant and bivariant lattice complexes.

All homogeneous sphere packings were derived that refer to the two invariant, the four univariant and the three bivariant lattice complexes belonging to the monoclinic crystal system. In total, sphere packings of 29 types have been found. Only for five types is the maximal inherent symmetry of their sphere packings monoclinic whereas the inherent symmetry is orthorhombic for nine types, tetragonal for five types, hexagonal for six types and cubic for four types.

Orthorhombic sphere packings. III. Trivariant lattice complexes with mirror symmetry.

All homogeneous sphere packings and all interpenetrating layers of spheres were derived that refer to the 18 orthorhombic trivariant lattice complexes with mirror symmetry. In total, sphere packings of 51 different types have been found. Only for 28 of these types is the maximal inherent symmetry of their sphere packings orthorhombic. Some crystal structures that can be described by means of sphere packings are listed.

Post-combustion syntheses of PCDD/F and PBDD/F from halogen-rich fuel is suppressed by a pebble heater technology.

GOAL, SCOPE AND BACKGROUND: Changes in German and European legislation shifted processing of polymer-rich shredding residues (SR) from landfill to thermal treatment. However, when waste of electric and electronic equipment (WEEE) is the source of SR, thermal treatment is complicated by halogens as well as the presence of polybrominated dioxins and furans (PBDD/F) and brominated flame retardants (BFR). Hence, WEEE requires high temperature incineration with sufficient residence times. Post-combustion synthesis of polyhalogenated dioxins and furans (PXDD/F) is dominant in the temperature range between 250-450 degrees C. Thus, a very rapid gas cooling from 450 degrees to 250 degrees C is important for proper raw gas treatment. The pebble heater technology developed by ATZ Entwicklungszentrum (Sulzbach-Rosenberg, Germany) might serve as an alternative to the state-of-the-art quench cooling. It is based on the application of a pebble bed of natural bulk material, which the exhaust gases flows through radially. It provides an excellent heat transfer and a temperature gradient in the range of 1,500-2,000 K/m. The paper presents data of a pilot application of the pebble heater technology for the treatment of raw gas derived from the incineration of polymeric materials from WEEE. METHODS: A liquid fuel was chosen in order to minimise technical modifications of the plant. It was analysed for halogens by x-ray fluorescence, for brominated flame retardants by HPLC-UV/MS and for PXDD/F by GC-HRMS. Combustion gases were rapidly cooled down to temperatures below 200 degrees C and emissions of PBDD/F and PCDD/ F were estimated without further off-gas treatment. PBDD/F emissions were computed as PCDD/F toxicity equivalents applying two different calculation approaches. RESULTS AND DISCUSSION: PCDD/F emissions accounted for 0.04 ng I-TEQ/Nm3 and are in compliance with European emission limits. Calculated PBDD/F toxicity equivalents exceeded the emission limit of 0.1 ng I-TEQ/Nm3 by factors of 75 and 208 depending on the calculation approach. A mass balance of PBDD/F and PCDD/F congeners revealed an efficient elimination of more than 95% in most cases. Lower reduction rates (76% for 2,3,7,8-TeBDF and 82% for 1,2,3,7,8-PeBDF) were attributed to incomplete combustion. An intended recovery of halogens by one-stage scrubbing downstream of the pebble heater was ineffective, recovering 28% of the applied chlorine and 9% of the bromine, only. CONCLUSIONS: Our pilot incineration test indicates that the pebble heater technology can effectively suppress a post-combustion synthesis of PCDD/F and PBDD/F, resulting in low PCDD/F emission levels without further off-gas treatment. The presented data state that WEEE is sensible to incomplete combustion, which will lead to increased PBDD/F emissions without increasing PCDD/F emission limits. This finding is especially relevant for small and low-technical incineration appliances, which have been reported to treat WEEE in developing countries and are considered to serve as a significant source of PXDD/F these days. RECOMMENDATIONS AND PERSPECTIVES: Monitoring of PCDD/F emissions only might considerably underestimate the total emission of dioxins and dioxin-like compounds. It is therefore an ineffective means for assessing resulting health risks, at least for those waste treatment plants which are considered to handle the increasing amounts of PBDD/ F-containing polymers from WEEE in future. Consequently, it is recommended to initiate a screening programme for PXDD/F emissions in large scale incineration facilities which are capable of treating WEEE shredder residues.

Orthorhombic sphere packings. II. Bivariant lattice complexes.

All homogeneous sphere packings and all interpenetrating layers of spheres were derived that refer to the 22 orthorhombic bivariant lattice complexes. In total, sphere packings of 90 different types have been found. Only for 47 of these types is the maximal inherent symmetry of their sphere packings orthorhombic. Some examples demonstrate the usefulness of sphere packings for the comparison and description of crystal structures.

Orthorhombic sphere packings. I. Invariant and univariant lattice complexes.

All homogeneous sphere packings and all interpenetrating sphere packings were derived that refer to the 6 invariant and the 11 univariant lattice complexes belonging to the orthorhombic crystal system. In total, sphere packings of 38 types have been found. Only for 17 types is the maximal inherent symmetry of their sphere packings orthorhombic. By means of a number of examples, the applicability of sphere packings for the comparison and description of simple crystal structures is demonstrated.

Interpenetration of homogeneous sphere packings and of two-periodic layers of spheres.

All systems of interpenetrating sphere packings that occur with highest symmetry in the cubic, hexagonal or tetragonal crystal family are tabulated. Homogeneous sphere packings belonging to 49 different types may be intertwined to systems of interpenetrating sphere packings belonging to 74 types. For all compatible lattice complexes, the coordinate and lattice parameters are given. The corresponding patterns of interpenetration are analysed. For the interpenetration of two, three, four, five and eight sphere packings, eleven, three, five, one and two different patterns, respectively, are distinguished. In addition, four types of interpenetrating layers of spheres were found. Each such sphere configuration splits into two or three subsets of parallel sphere layers with an angle of 90 degrees or of 120 degrees , respectively, between the directions of the normals of the layers. A single sphere layer corresponds either to a honeycomb net or to a net built up from quadrangles and octagons.

Diferenciación en las representaciones sociales de los trastornos mentales y los tratamientos psiquiátricos / No disponible

Puesto que la representación social de la enfermedad mental y su tratamiento juegan un papel importante en su detección y en la orientación de los pacientes hacia distintas terapias, es importante determinar si la sociedad diferencia entre los distintos trastornos mentales y sus tratamientos. Estas representaciones se examinan en una encuesta realizada en una muestra estratificada de la población suiza para tres enfermedades mentales, en términos de definición como enfermedad, etiología, tratamientos previstos y pronóstico. Existe una diferenciación clara entre esquizofrenia por un lado, y depresión y trastorno de pánico por otro. La esquizofrenia se considera con más frecuencia una enfermedad real con etiología multifactorial, un pronóstico más pesimista y para la que la psicoterapia y la terapia familiar son tratamientos recomendados. Hay, sin embargo falta de diferenciación en cuanto a los distintos factores etiológicos, en particular los factores psicosociales, que se consideran muy importantes, y ciertos tratamientos, especialmente la medicación, recomendada sólo por un cuarto de la población

Cytokine induction by purified lipoteichoic acids from various bacterial species--role of LBP, sCD14, CD14 and failure to induce IL-12 and subsequent IFN-gamma release.

We have recently shown that highly purified lipoteichoic acid (LTA) represents a major immunostimulatory principle of Staphylococcus aureus. In order to test whether this translates to other bacterial species, we extracted and purified LTA from 12 laboratory-grown species. All LTA induced the release of TNF-alpha, IL-1beta, IL-6 and IL-10 in human whole blood. Soluble CD14 (sCD14) inhibited monokine induction by LTA but failed to confer LTA responsiveness for IL-6 and IL-8 release of human umbilical vein endothelial cells (HUVEC). In a competitive LPS-binding protein (LBP) binding assay, the IC(50) of the tested LTA preparations was up to 3,230-fold higher than for LPS. LBP enhanced TNF-alpha release of human peripheral blood mononuclear cells (PBMC) upon LPS but not LTA stimulation. These data demonstrate a differential role for the serum proteins LBP and sCD14 in the recognition of LPS and LTA. Different efficacies of various anti-CD14 antibodies against LPS vs. LTA-induced cytokine release suggest that the recognition sites of CD14 for LPS and LTA are distinct with a partial overlap. While the maximal achievable monokine release in response to LTA was comparable to LPS, all LTA induced significantly less IL-12 and IFN-gamma. IL-12 substitution increased LTA-inducible IFN-gamma release up to 180-fold, suggesting a critical role of poor LTA-inducible IL-12 for IFN-gamma formation. Pretreatment with IFN-gamma rendered galactosamine-sensitized mice sensitive to challenge with LTA. In conclusion, LTA compared to LPS, are weak inducers of IL-12 and subsequent IFN-gamma formation which might explain their lower toxicity in vivo.

The absence of D-alanine from lipoteichoic acid and wall teichoic acid alters surface charge, enhances autolysis and increases susceptibility to methicillin in Bacillus subtilis.

In Bacillus subtilis the physiological consequences of depriving lipoteichoic acid and wall teichoic acid of D-alanine ester were analysed using insertional inactivation of the genes of the dlt operon. Mutant strains which lacked positively charged D-alanine ester in teichoic acids bound more positively charged cytochrome C than other strains. These mutant strains also showed enhanced autolysis and a higher susceptibility to methicillin, which was expressed as accelerated wall lysis, a faster loss of viability and a slower recovery in the postantibiotic phase. The effects of methicillin could be suppressed by simultaneous addition of magnesium ions at low concentrations. The degradation of whole bacteria by bone-marrow-derived macrophages was not influenced by the surface charge and alanylation of the teichoic acids had no protective effect.