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Ba(Ti1−x−ySnxGey)O3 (BTSG-x-y; x = 0, 0.05; y = 0–0.05) powders were synthesized by a sol-gel (SG) method and for comparative purposes also by a mixed-oxide (MO) method. In this system, BaGeO3 functions as sintering additive. Due to smaller particle sizes of the SG powders a higher sintering activity was found, which resulted in reduced grain growth and in a more homogenous grain size distribution for the corresponding ceramics. The dependence on the paraelectric ⇆ ferroelectric phase transition, i.e. the phase transition temperature, the width of the transition region and completeness were examined by dielectric measurements, DTA as well as by SEM, EDX and XRD investigations with respect to the BaGeO3 content, synthesis method and sintering temperature. The phase transition temperatures of the SG ceramics are remarkably higher than those of the MO ceramics with the same nominal compositions. The reason is a lower tin concentration within the grains of SG ceramics as confirmed by EDX and XRD investigations. The presence of BaGeO3 in barium titanate–stannate system on the basis of a SG method caused an improved incorporation of tin in the BaTiO3 lattice.

The formation of BaCeO3 by a co-precipitation method is described herein. The co-precipitation route leads to an orange (BaCe)-precursor powder (1). To improve the sintering behaviour, a small amount of Ge4+ was incorporated, leading to a (BaCe0.95/Ge0.05)-precursor (2). Both precursor powders results in fine-grained preceramic powders (1A, 2A) after calcination. The shrinkage and sintering behaviour of resulting powder compacts were studied in comparison to a coarse-grained mixed-oxide BaCeO3 powder (3). Compacts of 2A reach a relative density of 90% after sintering at 1350 °C with grain sizes between 0.9 and 3.2 μm. On the other hand ceramics of 1A and 3 have, after sintering at 1500 °C (10 h), relative densities of 85 and 76%, respectively. Ceramic bodies of 1A consisted of phase-pure orthorhombic BaCeO3, whereas bodies of 2A show reflections of BaCeO3 and a Ba2GeO4 phase. DTA investigations of samples 1A and 2A reveal three phase transitions at 255 °C (1A) and 256 °C (2A) as well as 383 °C (1A) and 380 °C (2A). A very weak one can be obtained in the range 880–910 °C.

DTA, XRD and sintering investigations of the system BaSnO 3 –BaGeO 3 , prepared by a mixed-oxide method, are described herein. The melting temperature of this system is about 1270 ± 5 °C. We find a partial solubility of BaGeO 3 into BaSnO 3 of the order of 6–7 mol%. Up to 50 mol% BaGeO 3 , the calcined powders (1150 °C) as well as the once-sintered samples consist of BaSnO 3 and orthorhombic BaGeO 3 at room temperature. A gradual appearance of hexagonal BaGeO 3 can be observed in calcined powders and once-sintered ceramics with a BaGeO 3 content above 50 mol%. After sintering at ≥1200 °C for more than 1 h all ceramic bodies consist of BaSnO 3 and orthorhombic BaGeO 3 . The addition of BaGeO 3 leads to a considerable reduction of the sintering temperature and to a strong densification. Sintering at 1180 °C for 10 h and an addition of only 1 mol% BaGeO 3 leads to dense ceramic bodies with cubic-like grains.

The formation of solid solutions of the type [Ba(HOC2H4OH)4][Sn1−x Ge x (OC2H4O)3] as BaSn1−x /Ge x O3 precursor and the phase evolution during its thermal decomposition are described in this paper. The 1,2-ethanediolato complexes can be decomposed to nano-sized BaSn1−x /Ge x O3 preceramic powders. Samples with x = 0.05 consist of only a Ba(Sn,Ge)O3 phase, whereas powders with x = 0.15 and 0.25 show diffraction patterns of both the Ba(Sn,Ge)O3 and BaGeO3 phase. The sintering behaviour was investigated on powders with a BaGeO3 content of 5 and 15 mol%. These powders show a specific surface area of 15.4–15.9 m2/g and were obtained from calcination above 800 °C. The addition of BaGeO3 reduced the sintering temperature of the ceramics drastically. BaSn0.95Ge0.05O3 ceramics with a relative density of at least 90% can be obtained by sintering at 1150 °C for 1 h. The ceramic bodies reveal a fine microstructure with cubical-shaped grains between 0.25 and 0.6 μm. For dense ceramics, the sintering temperature could be reduced down to 1090 °C, when the soaking time was extended up to 10 h.

Dielectric properties and the cubic ⇆ tetragonal phase transition temperature of dense BaTiO 3 ceramics containing 10 mol% BaGeO 3 , sintered between 840 and 1350 °C, have been investigated. The ceramic bodies were prepared from a nano-sized BaTi 0.9 /Ge 0.1 O 3 powder consisting of both BaTiO 3 and BaGeO 3 phases. The addition of BaGeO 3 leads to a reduction and broadening of the permittivity maximum, and to a small downshift of the paraelectric ⇆ ferroelectric phase transition temperature, compared to a pure BaTiO 3 ceramic. Lower sintering temperatures and thus small grain sizes of the ceramics cause an additional reduction of the maximum permittivity down to 2800. Both DTA and dilatometric measurements reveal also a downshifting of the phase transition temperature, as well as a decrease of the latent heat.

Preparation of a very fine BaSnO3 powder by calcination of a barium tin 1,2-ethanediolato complex precursor and its sintering behaviour are described herein. A rate controlled calcination process to 820 °C leads to a nm-sized BaSnO3 powder with a specific surface area of S = 15.1 m2/g (dav. = 55 nm). The powder has a slightly larger cell parameter of a = 412.22(7) pm compared to the single crystal value, which decreases with increasing calcination temperature and reaches the reference value above 1000 °C. The sintering behaviour is compared between fine and coarse-grained BaSnO3 powders. Corresponding powder compacts of the nano-sized BaSnO3 achieve a relative density of 90% after sintering at 1600 °C for 1 h and at 1500 °C and a soaking time of 30 h, whereas coarse-grained powder compacts reach only 80% of the relative density at 1650 °C (10 h). Furthermore, the shrinkage mechanisms of fine and coarse-grained powder compacts have been investigated and are discussed.

Detection of allergen-specific IgE represents the most important tool for in vitro diagnostic testing of food allergy. Applied methods vary in design (single allergen sources or mixtures, panel tests, single allergen components) and diagnostic efficacy. High specific IgE to hens egg, cows milk, peanut and fish is associated with an increased risk for clinical reactions, but rarely supersedes oral challenge tests. Cellular tests with basophil leukocytes, demonstrating IgE-mediated sensitizations indirectly, are useful only in selected cases. Particular protein families (i.e. Bet v 1 homologs, lipid transfer proteins and profilins) consist of allergenic molecules with similar sequence and structure. Their shared IgE binding sites form the basis of cross-reactivity. Cross-reactive carbohydrate determinants (CCD), frequently from plant origin, can also bind IgE being rarely clinically relevant. Allergy to plants (i.e. tree nuts, fruits, legumes) and animals (cows milk, hens egg, fish) is diagnosed with extracts, if their quality is sufficient. Detecting IgE to single allergenic components allows molecule-specific diagnoses, their value varies for each allergen source and single allergen component. Allergen-specific IgE detections are indicated in case of suspected food-allergic reactions despite uncertain history and skin tests, sensitizations to foods not applicable for skin testing, severe reactions to foods, conditions hampering skin testing or its interpretation, and in children. Interpreting should consider incorrect results due to inferior reagents or laboratory errors and clinically irrelevant results due to highly elevated total IgE, low assay thresholds or cross-reactive allergens (errors of interpretation). Positive test results indicate allergen-specific sensitizations, being clinically relevant only in case of corresponding symptoms. The following methods are not useful for diagnosing food allergy: bioresonance, electroacupuncture, kinesiology, cytotoxic food allergy test (methods without validity and/or evidence), lymphocyte stimulation test, food-specific IgG and IgG4 (methods with invalid interpretation).

Summary Chronic urticaria, recurrent angioedema and non-allergic asthma have all been associated with pseudoallergic reactions to food ingredients. For atopic dermatitis and diseases of the gastrointestinal tract, this association is controversial. Pseudoallergic reactions can be elicited by additives as well as by natural food ingredients. An altered histamine metabolism may be associated with pseudoallergy. Acute urticaria or a short episode of angioedema is not an indication for exhaustive evaluation. If basic diagnostic screening is negative in chronic urticaria, a low-pseudoallergen diet can be considered. Skin and serological tests are not objective diagnostic parameters for pseudoallergic reactions. The severity of symptoms should be documented while the patient is on a low-pseudoallergen diet. Oral provocation with additives leads to reproducible symptoms only in a few cases. Therefore, if a low-pseudoallergen diet brings improvement, the patient is then exposed to a pseudoallergen-rich “super meal”. After a positive reaction to the “super meal” the challenge with additives takes place in the form of collective group exposition. When the patient has asthma or a history of anaphylactoid reactions, testing with individual substances in carefully increasing dosages is required. The suspicion of adverse reactions against histamine can be confirmed by a challenge with histamine dihydrochloride. In the case of respiratory symptoms, provocation by inhalation should be considered. Objectifying symptoms especially in gastrointestinal diseases is mandatory and should include double-blind placebo-controlled food challenge, if possible.

The shrinkage mechanism of BaTiO 3 powder compacts containing 10 mol% BaGeO 3 , synthesized by a precursor route and a conventional mixed-oxide method, are described herein. The calcination of a barium titanium germanium 1,2-ethanediolato complex precursor – [Ba(HOC 2 H 4 OH) 4 ][Ti 0.9 Ge 0.1 (OC 2 H 4 O) 3 ] ( 1 ) – at 730 °C leads to a nm-sized Ba(Ti 0.9 /Ge 0.1 )O 3 powder ( 1a ) ( S BET = 16.9 m 2 g −1 ) consisting of BaTiO 3 and BaGeO 3 . Whereas the conventional mixed-oxide method yields a powder ( 2 ) with a specific surface area of S BET = 2.0 m 2 g −1 . Powder compacts of 1a start to shrink at 790 °C and the shrinkage rate reaches a maximum at 908 °C. Dense ceramic bodies can be obtained below the appearance of the liquid melt (1120 °C), therefore the shrinkage of 1a can be described by a solid state sintering mechanism. Otherwise the beginning of the shrinkage of powder 2 is shifted to higher temperatures and the formation of the liquid melt is necessary to obtain dense ceramic bodies. Isothermal dilatometric investigations indicate that the initial stage of sintering is dominated by sliding processes. XRD investigations show that below a sintering temperature of 1200 °C ceramic bodies of 1a consist of tetragonal BaTiO 3 and hexagonal BaGeO 3 , whereas temperatures above 1200 °C lead to ceramics containing orthorhombic BaGeO 3 , and a temperature of 1350 °C causes the formation of a Ba 2 TiGe 2 O 8 phase. The phase evolution of ceramic bodies of 2 is similar to 1a , however a Ba 2 GeO 4 phase is observed below a temperature of 1100 °C.

Chronic urticaria, recurrent angioedema and non-allergic asthma may be due to pseudoallergic reactions to food ingredients. For atopic dermatitis and gastrointestinal symptoms the role of these non-allergic reactions is discussed controversially. Pseudoallergic reactions can be elicited by food additives as well as naturally occurring food components. An altered histamine metabolism may be associated with pseudoallergy. Extensive diagnostic measures are not indicated for an acute urticaria or a short episode of angioedema. Only when symptoms become chronic or at least intermittent, basic diagnostic measures are justified. If this procedure is unsuccessful, pseudoallergy to food components should be considered as a causative factor. In order to confirm this suspicion, patients should adhere to a low pseudoallergen diet for 3 weeks. During this period, a daily documentation of symptoms is recommended. As the underlying pathomechanism is not IgE-mediated, skin and blood tests are not useful for diagnosis. After apparent improvement or remission of symptoms, the causative role of a low pseudoallergen diet can be proven by re-exposure to foods rich in pseudoallergens over 2 days. As food additives only play a minor role in pseudoallergic reactions, a mixture of relevant food additives can be given at one time in most patients. Patients with asthma bronchiale or a history of anaphylactoid reactions should be challenged with single food additives in increasing doses. If adverse reactions to histamine are suspected, an oral provocation with histamine dihydrochloride is recommended. For patients with respiratory symptoms inhalant challenge tests are suggested. Double-blind, placebo-controlled food challenge is recommended if the patient suffers from gastrointestinal symptoms only and pseudoallergy is suspected.

Nanoscaled Ba(Ti1−x−ySnxGey)O3 (BTSG − x − y, x = 0–0.1, y = 0–0.05) powders were synthesized by a sol–gel method (SG) and, as a reference, coarse powders by a mixed-oxide method (MO). The particle sizes were determined by XRD, BET, photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM). The sol–gel method supplied globular particles with narrow fractions in the range between 53 nm and 125 nm. However, from the mixed-oxide method irregularly grown particles were generated with diameters between 300 nm and 700 nm. The SG powders showed a higher sintering activity and, additionally, Sn4+ ions were incorporated at lower temperatures into the BaTiO3 structure. The addition of at least 2 mol% BaGeO3 (BG) resulted in ceramics of densities as high as 96% even at 1050 °C. Furthermore, the cubic ⇆ tetragonal phase transition temperatures were measured by dilatometry, differential thermal analysis (DTA) and dielectric measurements. The temperature and sharpness of the transition are dependent on tin and germanium content. Increasing tin and germanium concentration causes the phase transition temperature to decrease and more diffuse transition.

Zusammenfassung Grundlage für die Mehrzahl IgE-vermittelter Nahrungsmittelallergien im Erwachsenenalter sind kreuzreagierende Allergene. Ähnliche Molekülstrukturen in Inhalations- und Nahrungsmittelallergenen bedingen die Bildung kreuzreagierender IgE-Antikörper. Damit wird infolge der Sensibilisierung gegen ein Kreuzallergen, meist primär ein Inhalationsallergen, ein ganzes Spektrum an Sensibilisierungen ausgelöst, und bereits der Erstkontakt mit dem Nahrungsmittel kann eine anaphylaktische Reaktion provozieren. Die größte Bedeutung haben pollenassoziierte Nahrungsmittelallergien, wobei die baumpollenassoziierten Allergien am besten untersucht sind. Für die klinische Praxis reicht es nicht aus, mittels immunologischer Tests eine Kreuzreaktion nachzuweisen, sondern es muss zwischen einer Sensibilisierung ohne klinische Relevanz und einer klinischen Manifestation der Allergie unterschieden werden, weswegen bei unklarer Anamnese die Durchführung oraler Provokationstests notwendig wird. Dass baumpollenassoziierte Nahrungsmittelallergien durch die spezifische Immuntherapie mit Baumpollen eine Besserung erfahren können, zeigen einige offene Studien an Baumpollenallergikern. Wenigstens 50% dieser Patienten mit zusätzlichen Symptomen auf Nahrungsmittel beobachteten unter der Immuntherapie neben einer Besserung der polleninduzierten Beschwerden auch einen positiven Einfluss auf die Nahrungsmittelallergie. Allerdings stehen plazebokontrollierte Studien aus. Angesichts der Zunahme der Pollenallergien, der Verschiebung des Sensibilisierungsspektrums und einer Änderung unserer Essgewohnheiten muss mit neuen, bisher unbekannten Kreuzreaktionen gerechnet werden.

We describe the preparation and crystal structures of the ionic complexes [Cu(bipy)2{ONC(CN)2}]CF3SO3 (1b), [Cu(phen)2{ONC(CN)2}]PF6 (2p) and [Cu(bipy)2{ONC(CN)2}]PF6 (2b). In the complex cations [Cu(L)2{ONC(CN)2}]+ (L is 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen)) the two molecules of bipy or phen coordinate to the copper atom through two nitrogen atoms along with the oxygen atom of the nitrosodicyanomethanide anion, ONC(CN) 2 − , to form a {CuN4O} chromophore with a distorted square pyramidal coordination sphere in (1b) and (2b) and a distorted trigonal bipyramidal geometry in (2p). The basal plane in (1b) and (2b) is formed by an oxygen atom coordinated at the Cu1–O1 distance of 1.990(2) and 2.002(2) A, respectively, and three nitrogen atoms coordinated to the copper atom at similar distances with the average of 2.01(2) and 2.00(3) A, respectively. The axial position is occupied by the fourth N atom at the longer distance of 2.222(2) and 2.185(2) A, respectively. The trifluoromethanesulfonate anion (triflate), CF3SO 3 − , in (1b) might be considered as very weakly coordinated in the opposite axial position (Cu1–O2 = 2.719(2) A). The equatorial plane in (2p) is formed by an oxygen atom coordinated at the Cu1–O1 distance of 1.975(3) A, and two nitrogen atoms from different phen molecules coordinated to the copper atom at the same distance within 2 σ with the average distance of 2.124(2) A. The axial positions are occupied by remaining two nitrogen atoms coordinated at shorter distance (average Cu–N = 1.99(3) A). The hexafluorophosphate anions, PF 6 − , in (2p) and (2b) remain uncoordinated. Besides the ionic forces, the structures of (2p) and (2b) may be stabilized by very weak C–H···F whereas the structure of (1b) by very weak C–H···F, C–H···O and C–H···N hydrogen bonds. The structural–spectral correlations are also discussed.

The formation of solid solutions of the type [Ba(HOC2H4OH)4][Ti1−xGex(OC2H4O)3] as Ba(Ti1−x/Gex)O3 precursors and the phase evolution during thermal decomposition of [Ba(HOC2H4OH)4][Ti0.9Ge0.1(OC2H4O)3] (1) are described herein. The 1,2-ethanediolato complex 1 decomposes above 589 °C to a mixture of BaTiO3 and BaGeO3. A heating rate controlled calcination procedure, up to 730 °C, leads to a nm-sized Ba(Ti0.9/Ge0.1)O3 powder (1a) with a specific surface area of S = 16.9 m2/g, whereas a constant heating rate calcination at 1,000 °C for 2 h yields a powder (1b) of S = 3.0 m2/g. The shrinkage and sintering behaviour of the resulting Ba(Ti0.9/Ge0.1)O3 powder compacts in comparison with nm-sized BaTiO3 powder compacts (2a) has been investigated. A two-step sintering procedure of nm-sized Ba(Ti0.9/Ge0.1)O3 compacts (1a) leads, below 900 °C, to ceramic bodies with a relative density of ≥90%. Furthermore, the cubic ⇆ tetragonal phase transition temperature has been detected by dilatometry, and the temperature dependence of the dielectric constant (relative permittivity) has also been measured.

Zusammenfassung Den wichtigsten Stellenwert für die In-vitro-Diagnostik von Nahrungsmittelallergien hat die Bestimmung des allergenspezifischen Immunglobulin E (IgE), i. d. R. nach Anamnese und Hauttest durchgeführt. Hunderte von Einzelallergenen und Kombinationen werden von einer Reihe von Herstellern angeboten. Unterschiedliche Allergene, Detektions- und Kalibrierungsmethoden erlauben selten einen direkten Vergleich der Resultate; sie können außerdem erheblich von den anamnestischen Angaben, den Ergebnissen im Hauttest und in der oralen Provokation abweichen. Zelluläre Laborverfahren (Histamin-Release-, Basophilen-Aktivierungs-Test und Leukotrien-freisetzungstest/CAST) sind für die Diagnostik von IgE-vermittelten Nahrungsmittelallergien derzeit nur in Einzelfällen bzw. für wissenschaftliche Fragestellungen zu empfehlen. Nahrungmittelallergene: Klassische Nahrungsmittelallergene (häufiger im Kindesalter) bereiten als stabile Proteine selten Schwierigkeiten für die IgE-Diagnostik. Eine Bestimmung des IgE gegen definierte Proteine (z. B. Einzelallergene aus Kuhmilch oder Hühnerei) statt gegen das Gesamtprotein bringt gegenwärtig keine Vorteile für die Routinediagnostik. Bei Pollen- oder Latexsensibilisierung wird häufig IgE gegen kreuzreaktive, vorwiegend instabile Allergene in diversen Obst-, Gemüse- und Pflanzensorten nachgewiesen, das nur bei korrespondierenden Symptomen klinisch relevant ist – ein weiteres Argument für eine verdachtsorientierte, gezielte In-vitro-Diagnostik. Indikationen für die IgE-Dianostik: begründeter Verdacht einer Nahrungsmittelallergie, aber keine klare Aussage nach Anamnese und Hauttest, Sensibilisierung auf Hauttest-ungeeignete Nahrungsmittel, bedrohliche Reaktion auf Nahrungsmittel, Hauttest bzw. seine Auswertung nicht möglich. Interpretation der Ergebnisse: falsche Ergebnisse durch unzureichende Reagenzienqualität oder Laborfehler (technische und methodische Fehler), klinisch nicht relevante Ergebnisse durch stark erhöhtes Gesamt-IgE, zu hohe Nachweisempfindlichkeit oder kreuzreagierende Allergene (Interpretationsfehler). Untauglich zur Nahrungsmittelallergie-Diagnostik: spezifisches IgG, zytotoxischer Lebensmitteltest, Elektroakupunktur, Bioresonanz (Methoden ohne Aussagekraft und/ oder Überprüfung). Ungelöste Probleme: optimale Qualität der Reagenzien, Kalibration und Vergleichbarkeit unterschiedlicher Methoden, serologische Kreuzreaktivität. Zukünftige Studien zur klinischen Relevanz der In-vitro-Ergebnisse werden die Diagnostik und Beurteilung einer Nahrungsmittelallergie verbessern helfen.

From the reaction mixtures containing Cu(NO3)2, Na[N(CN)2], KPF6 and 2,2′-bipyridine (bpy) or 1,10- phenanthroline (phen) in 1:1:1:2 molar ratios, [Cu(bpy)2N(CN)2][Cu(bpy)2(H2O)](PF6)3(1b) and [Cu (phen)2N(CN)2]PF6(1p) complexes were isolated. Measured i.r. spectra confirm the presence of all functional groups in both complexes and, moreover, they indicate monodentate coordination of dicyanamide through the cyano nitrogen atom in (1p). The structure of (1b) contains two crystallographically independent complex cations. In both, Cu is coordinated by two chelating bpy molecules, and either dicyanamide anion or water molecule fills the fifth position, completing the basal plane. The CuII atoms in (1p) are coordinated by two chelating phen ligands and by one dicyanamide anion in the equatorial plane. Hexafluorophosphate anions in (1b) and (1p) remain uncoordinated. Besides the ionic forces in both structures, the structure of (1b) is stabilized by strong O—H………F and O—H………N hydrogen bonds and, moreover, both structures are stabilized by weak C—H………F hydrogen bonds and possible π-π interactions between pyridine rings of bpy or phen molecules.

The synthesis of [Ba(C2H6O2)4][Ti(C2H4O2)3], its crystal structure and thermal decomposition is described. This 1,2-ethanediolato complex forms with the isotypic tin compound [Ba(C2H6O2)4][Sn(C2H4O2)3] solid solutions [Ba(C2H6O2)4][Ti1−xSnx(C2H4O2)3] in any ratio. Corresponding mixed crystalline samples are suitable precursor complexes for BaTi1−xSnxO3 ceramics with the feature of a heavy element distribution in molecular scale matching the element distribution of the final ceramics.

Grundlage fur die Mehrzahl IgE-vermittelter Nah rungsmittelallergien im Erwachsenenalter sind kreuzreagierende Allergene. Ahnliche Molekul strukturen in Inhalations- und Nahrungsmittelallergenen bedingen die Bildung kreuzreagierender IgE-Antikorper. Damit wird infolge der Sensibilisierung gegen ein Kreuzallergen, meist primar ein Inhalationsallergen, ein ganzes Spektrum an Sensibilisierungen ausgelost, und bereits der Erstkontakt mit dem Nahrungsmittel kann eine anaphylaktische Reaktion provozieren. Die groste Bedeutung haben pollenassoziierte Nahrungsmittelallergien, wobei die baumpollenassoziierten Allergien am besten untersucht sind. Fur die klinische Praxis reicht es nicht aus, mit tels immunologischer Tests eine Kreuzreaktion nach zuweisen, sondern es muss zwischen einer Sensibilisierung ohne klinische Relevanz und einer klinischen Manifestation der Allergie unterschieden werden, weswegen bei unklarer Anamnese die Durchfuhrung oraler Provokationstests notwendig wird. Dass baumpollenassoziierte Nahrungsmittelall ergien durch die spezifische Immuntherapie mit Baumpollen eine Besserung erfahren konnen, zeigen einige offene Studien an Baumpollenallergikern. Wenigstens 50% dieser Patienten mit zusatzlichen Symptomen auf Nahrungsmittel beobachteten un ter der Immuntherapie neben einer Besserung der polleninduzierten Beschwerden auch einen positi ven Einfluss auf die Nahrungsmittelallergie. Aller dings stehen plazebokontrollierte Studien aus. Angesichts der Zunahme der Pollenallergien, der Verschiebung des Sensibilisierungsspektrums und einer Anderung unserer Essgewohnheiten muss mit neuen, bisher unbekannten Kreuzreakti onen gerechnet werden.

[Ba2(C2H6O2)4][Ge2(C2H4O2)6] · 2.5 C2H6O2 (3a) is isolated from the reaction of GeO2 · aq with Ba(OH)2 · 8 H2O in glycol (1,2-ethanediol). 3a crystallizes in the space group P-1 with a = 10.324(2) Å, b = 13.932(3) Å, c = 15.800(3) Å, α = 102.86(2)°, β = 91.33°, γ = 109,47° and V = 2077.2(7) Å3. With increasing temperature 3a looses glycol and forms step by step [Ba(C2H6O2)2][Ge(C2H4O2)3] (3b), Ba[Ge(C2H4O2)3] (3c) and finally hexagonal BaGeO3 (4).

Nanocrystalline BaTi 0.95 Sn 0.05 O 3 (BTS-5) powder was synthesised from glycolate-precursors, and used to sinter fine-grain BTS-5 ceramics. We compare sintering behaviour, microstructure as well as dielectric and electromechanical properties of the advanced ceramics with ceramics sintered from classical mixed oxide powder.

The title compound, [Cu(C(2)N(3))(C(12)H(8)N(2))(2)]ClO(4), represents a relatively rare class of compounds with dicyanamide coordinated in a monodentate manner. The structure is formed by the [Cu{N(CN)(2)}(phen)(2)](+) complex cation (phen is 1,10-phenanthroline) and an uncoordinated ClO(4)(-) anion. The Cu atom is five-coordinate, with a slightly distorted trigonal-bipyramidal environment. The dicyanamide ligand is coordinated through one nitrile N atom in the equatorial plane, at a distance of 2.033 (6) angstroms from the metal. The two axial Cu-N distances are similar [mean 1.999 (4) angstroms] and are substantially shorter than the remaining two equatorial Cu-N bonds [mean 2.087 (1) angstroms].

The ionic [Cu(C2N3)(C10H8N2)2](CF3SO3) compound, which contains two crystallographic independent formula units, is formed by [Cu(bpy)2(dca)]+ complex cations (bpy=2,2′-bipyridine, dca=dicyanamide) and uncoordinated CF3SO 3 – anions, which are in a staggered conformation. The shapes of coordination polyhedra around both copper atoms, which are fivefold coordinated by two bpy molecules and one dca ligand monodentately coordinated through a cyano N atom in the equatorial plane at a distance of 2.001(3)A for the first and 1.988(4)A for the second polyhedron, are distorted trigonal bipyramids. Besides the ionic forces the structure is stabilized by weak C–H...O hydrogen bonds and possible π–π interactions between pyridine rings of bpy molecules. Along with the structural-spectral correlation we discuss the thermal decomposition of the title complex.

Triethylenetetramine (L4) and dipropylenetriamine (L3) were used as blocking ligands (tetradentate and tridentate, respectively) that, after complexation with Ni(II), leave two or three sites ready for ligation with N ( CN ) 2 - (dicyanamide, abbr. dca). The formed complexes are mononuclear, binuclear or polymeric. This was proven by the X-ray structure analysis for [NiL4(dca)2] (mononuclear, 1), [(dca)L3Ni(dca)2NiL3(dca)] (binuclear, 2) and [NiL4(dca)](ClO4) (polymeric, 3). The magnetic susceptibility measurements for 1 confirm that the Curie law is obeyed at higher temperatures whereas the zero-field splitting is effective below 10 K (D/hc = −4 cm−1); 2 shows a weak antiferromagnetic coupling (J/hc = −0.6 cm−1); 3 exhibits a negligible exchange coupling (J/hc ≈ 0).

The structure of Ph[PhC(O)NH]2PNC(O)Ph (2) in solid state and in solution is discussed on the basis of a crystal structure analysis and IR and Raman spectra. In crystalline state 2 forms dimers which are associated via two pairs of bifurcated (N–H)2⋯OC hydrogen bonds. The spectroscopic data are in good agreement with the crystallographic results with respect to the hydrogen bonding and they suggest that 2 also in solution is associated.

The thermal expansion ST has been measured in the system BaTi1−xSnxO3, both for the pure compositions x=0 (BT) and x=1 (BS), and for solid solutions 0.025≤x≤0.2 (BTS). For all ceramics examined, a non-linear temperature dependence ST(T) has been observed at elevated temperatures T>400 K . This is related to thermally generated impurities and, below the Burns-temperature Td of BT and BTS, to the non-linear strain contribution of polar nanoregions. With increasing Sn-content x, a steep increase of the Burns-temperature is found in BTS for compositions x≥0.025.

Durch hydrothermale sowie mikrowellenassistierte hydrothermale Reaktion von SnO2·aq mit Bariumhydroxid entsteht Ba[Sn(OH)6] (1) in Form stabchenformiger Partikel. Verbindung 1 gleicher Morphologie kann auch durch hydrothermale Umsetzung von [Ba(C2H6O2)4][Sn(C2H4O2)3] (3) gewonnen werden. Durch Umsetzung von SnO2·aq mit Ba(OH)2·8H2O in Ethylenglykol erhalt man das Glykolat [Ba(C2H6O2)4][Sn(C2H4O2)3] (3), das durch Rekristallisation aus Methanol [Ba(C2H6O2)2][Sn(C2H4O2)3]· CH3OH (4) bildet. Die Verbindungen 1, 3 und 4 liefern bei unterschiedlichen Temperaturen BaSnO3-Pulver (2) unterschiedlicher Morphologie; aufgrund der Korngrose der resultierenden Pulver sind die Verbindungen 3 und 4 als Precursor fur die Herstellung von Keramiken geeignet.

The reactions of diphenoxyphosphoryl chloride ((PhO) 2 P(O)Cl) and different chlorophosphonium salts ([R 3 PCl]X, R = (CH 3 ) 2 N, pyrrolidine, X = PF 6 m , BF 4 m ), respectively, with 7-aza-1-hydroxybenzotriazole (HOAt), 1-hydroxybenzotriazole (HOBt), hydroximinomalonitrile (HOxDCO), and ethyl hydroximinocyanoacetate (HOxO) are described. The structures of the new compounds, which are useful coupling reagents for epimerization-free peptide segment condensation, are discussed on the basis of their 1 H, 13 C, 31 P NMR, and IR spectra. The reactions of (PhO) 2 P(O)Cl lead to mixtures of O - and N -phosphorylated isomers of varying ratios. Contrary, reactions of chlorophosphonium salts yield exclusively one isomer.

New cyanamidonitrate-cobalt(II) complexes of the type [Co(NO 2 NCN) 2 L 4 ], where L=pz (pyrazole), mpz [3(5)-methyl-pyrazole], dmpz (3,5-dimethylpyrazole), inz (indazole, benzopyrazole), Br-pz (4-Br-pyrazole), and [Co(dmpz) 4 ](NO 2 NCN) 2 have been prepared and characterized by IR and electronic spectroscopy. The crystal structure of [Co(NO 2 NCN) 2 (pz) 4 ] was determined by X-ray crystallography. The donor set of Co(II) forms an octahedron with four tertiary nitrogens from pyrazole ligands situated in the equatorial plane and two nitrile nitrogens from cyanamidonitrates in the axial positions. The d–d transitions show that a similar molecular structure can be expected in other Co(II) complexes under study, except the [Co(dmpz) 4 ](NO 2 NCN) 2 which contains a tetrahedral complex cation and forms with [Co(NO 2 NCN) 2 (dmpz) 4 ] an isomeric pair. The central Co(II) atom in [Co(2-methylimidazole) 4 ] (NO 2 NCN) 2 complex is tetrahedraly coordinated with four tertiary nitrogens from the imidazole ligands and the formed cationic unit is balanced by free cyanamidonitrate anions. According to the electronic and infrared spectra the [Co(dmpz) 4 ](NO 2 NCN) 2 complex possesses an analogous molecular structure.

From reaction mixtures containing the same reagents, the two novel title complexes, with unusual coordination modes of the dicyan­amide (dca) ligand, have been prepared. The first compound, [Cu(C2N3)(C10H8N2)2]ClO4, represents a relatively rare class of compounds, with the dca ligand coordinated in a monodentate manner. Its structure is formed by the [Cu(bpy)2{N(CN)2}]+ complex cation (bpy is 2,2′-bi­pyridine) and a ClO4− anion, which does not enter the inner coordination sphere. The Cu centre is five-coordinate within a strongly distorted trigonal bipyramid to two bpy mol­ecules and one dca ligand, which is coordinated through one nitrile N atom in the equatorial plane. The second compound, [Cu2(C2N3)(C10H8N2)4](ClO4)3·0.5C2H6O, contains dca coordinated in the more common bidentate manner, but instead of a chain structure, a unique binuclear complex is formed. The asymmetric unit consists of the [Cu(bpy)2{N(CN)2}(bpy)2Cu]3+ binuclear complex cation, the charge of which is neutralized by three uncoordinated perchlorate anions, and a half-mol­ecule of ethanol. Both Cu centres in the cation are five-coordinate, adopting a slightly distorted trigonal–bipyramidal environment.

Measurement of allergen-specific IgE represents the most useful diagnostic in-vitro test in food allergy, usually being performed after case history and skin test. Hundreds of single allergens and combinations are offeredby a number of manufacturers. Different allergens, detection and calibration methods lead to a lack of comparibility of test results, which can also differ substantially from case history, skin test and food challenge results. Cellular laboratory tests should be used for food allergy testing only in individual cases or scientific studies. Food allergens: Food proteins of higher stability (predominantly relevant in early infancy) do rarely cause problems in terms of IgE-testing. At present, use of defined proteins for routine diagnosis of allergen-specific IgE has no advantage compared to whole food allergens. Resulting from sensitizations to pollen allergens or natural rubber latex, IgE will be found to cross reactive, mostly labile allergens from various fruit, vegetable or plant species, being clinically relevant only in case of corresponding symptoms. This supports the recommendation of selected in-vitro testing, focussing on suspected foods. Indication for IgE-testing: Reasonable probability of food allergy, but no clear-cut evidence after case history and skin test; sensitization to foods not suitable for skin testing; severe reactions to foods; skin test or its interpretation not possible. Interpretation of in-vitro results: False positive or negative results due to inappropriate reagents or laboratory errors; clinically irrelevant results by strongly elevated total serum IgE, low cut-off levels or cross reactive allergens. Not suitable for diagnosis of food allergy: Allergen-specific IgG, cytotoxic food test, electroacupuncture, bioresonance. Unsolved problems: Optimized quality ofreagents; calibration and comparability of results from different methods; serological cross reactivity. Future studies adressing clinical relevance of in-vitro results will help to improve diagnosis and interpretation of food allergy.

Measurement of allergen-specific IgE represents the most useful diagnostic in-vitro test in food allergy, usually being performed after case history and skin test. Hundreds of single allergens and combinations are offered by a number of manufacturers. Different allergens, detection and calibration methods lead to a lack of comparibility of test results, which can also differ substantially from case history, skin test and food challenge results. Cellular laboratory tests should be used for food allergy testing only in individual cases or scientific studies.

The structure of the new compound [Cu(bpy)2N(CN)2]C(CN)3 (6) is compared with thestructures of six copper(II) coordination compounds with phenanthroline or bipyridine ligands and N-donor pseudohalide anions: [Cu(phen)2NCS]C(CN)3 (1), [Cu(bpy)2NCS]C(CN)3 (2), [Cu(phen)2NCS]ONC(CN)2 (3), [Cu(phen)2N(CN)2]C(CN)3 (4), [Cu(bpy)2C(CN)3]C(CN)3 (5), and [Cu(bpy)2NCO]C(CN)3 (7). The Cu(II) atoms in all above compounds are five-coordinated with an N-donor atom of the pseudohalide anion located in the equatorial plane of a deformed trigonal bipyramid. The shape of the coordination polyhedra and the degree of trigonal bipyramidal distortion towards a tetragonal pyramid are discussed and described using one electronic and several structural criteria which are discussed and compared.

Complexation of NiII ion with triethylenetetramine (teta) and potassium tricyanomethanide KC(CN)3 yielded a new binuclear complex, [(teta)Ni(C(CN)3)2Ni(teta)](ClO4)2 (1), where two nickel(II) centres are held together by two tricyanomethanide bridges. The dinuclear units are aggregated into ladders; four of them being identified inside the unit cell. The effective magnetic moment on the cooling exhibits a slight gradual increase until 25 K; below this limit a strong, abrupt ferromagnetic interaction culminating at 16 K appears.

This review summarizes data for all known tricyanomethanide and dicyanamide compounds of copper(II), nickel(II) and cobalt(II). The possible bonding modes of [C(CN)3]− and [N(CN)2]− ions and their influence on infrared spectra are demonstrated. Preparative methods are briefly described and structural data for crystallographically characterized compounds are given. Data for electronic and ESR spectra, magnetic susceptibilities, vibrational and ESCA spectra are reviewed and consequences following from these techniques for structural characteristics are discussed. The most striking features of the behaviour of both pseudohalide ligands are their polydentate character and ability for bridging. This ability is revealed by many physical properties, especially by the temperature dependence of magnetic susceptibilities, in which exchange interaction through pseudohalide bridges is manifested. Reactivity of C(CN)3 and N(CN)2 groups in the coordination sphere of Cu(II) and Ni(II) is mentioned.

The title compound Ag[NCC{C(CN)2}2] (1) is a coordination polymer with a three-dimensional network. Two crystallographically different silver atoms and two 1,1,2,3,3-pentacyanopropenide ions, as well, are found. The coordination spheres of the atoms Ag1 and Ag2 are distorted AgN4 tetrahedra. Both metal atoms are coordinated via end-on nitrile groups of C(CN)2 units and at a time two metal atoms are doubly bridged by C(CN)2 or C(CCN)2 moieties of two tetradentate pentacyanopropenide ions forming 12- or 16-membered rings.

New cyanamidonitrate complexes with imidazole (iz) and its methyl derivatives (meiz) of the type [M(NO2NCN)2L4] (with M=Ni, L=iz, 1-, 2-, 4-meiz; M=Co, L=iz, 1-, 4-meiz) and [CoL4](NO2NCN)2 (with L=iz, 2-meiz) have been prepared and characterized by spectroscopic methods. The crystal structures of [Ni(NO2NCN)2(1-meiz)4] and [Co(NO2NCN)2(iz)4] have been determined by X-ray crystallography. The metal(II) environment is practically octahedral, composed of four tertiary nitrogens from imidazole ligands and two nitrile nitrogens from cyanamidonitrate groups. According to the spectral results, similar molecular structures can be assumed for all remaining [M(NO2NCN)2L4] compounds. On the other hand, compounds [CoL4](NO2NCN)2 consist of tetrahedral complex cations [CoL4]2+ which are electrostatically attracted with NO2NCN−. An isomeric pair, [Co(NO2NCN)2(iz)4] and [Co(iz)4](NO2NCN)2, of octahedral and tetrahedral structure, respectively, were characterized.

The crystal and molecular structures of the title compounds have been determined. Ph2P(O)NC(NH2)NHPh (1) crystallizes in the space group P212121 with four molecules in the unit cell of dimensions: a=9.183(1), b=11.699(1), c=16.554(2) A. Ph2P(S)NC(NH2)NHPh (2) crystallizes in the space group P 1 with four molecules in the unit cell of dimensions: a=9.479(2), b=13.695(1), c=14.037(1) A, α=82.98(1), β=89.31(1), γ=87.67(1)°. The structures were solved by direct methods. The molecules of 1 and 2 are associated via weak intermolecular NH⋯O (1) and NH⋯S (2) hydrogen bonds, respectively. Besides that, weak intramolecular interactions were observed between the NH2 group and the chalcogen atom in both structures. Additionally, hydrogen bonds were characterized by IR spectroscopy in solution as well as in the solid state in dependence on temperature.

Procalcitonin (PCT), the precursor of calcitonin, was recently put forward as a diagnostic marker of systemic bacterial infection and sepsis. The major PCT production site in sepsis still remains unclear. Because of a certain association between increased levels of PCT and leukocyte-derived cytokines during sepsis, we assessed the possible expression of PCT in human peripheral blood mononuclear cells (PBMCs) and the modulation of PCT by lipopolysaccharides (LPS) and various sepsis-related cytokines by reverse transcriptase-polymerase chain reaction (RT-PCR) by using a novel primer set and flow cytometric analysis with intracellular staining with antibodies to the PCT components calcitonin and katacalcin. RT-PCR and flow cytometric analysis demonstrated that PBMCs express PCT both on mRNA and on protein levels. LPS and various proinflammatory cytokines (interleukin-1beta (IL-1beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), IL-2) had pronounced stimulatory effects on the expression of PCT mRNA. Under identical experimental conditions the anti-inflammatory cytokine IL-10 had no effect on the expression of mRNA for PCT. Flow cytometric analysis demonstrated increased intracellular amounts of PCT components after LPS stimulation. Thus we demonstrate for the first time that PCT is expressed in PBMCs. This expression is modulated by bacterial LPS and sepsis-related cytokines. Therefore PBMCs may be among the sources of elevated PCT levels in patients with sepsis.

New cyanamidonitrate–copper(II) complexes [Cu(NO2NCN)2Ln] (L=imidazole (iz), n=2; L=iz, 1-, 2- or 4-methylimidazole (meiz), n=4) have been isolated and characterised by IR, electronic and ESR spectroscopy. The crystal structures of 1- and 4-meiz complexes have been determined by X-ray crystallography; the structure of [Cu(NO2NCN)2(iz)2] is known (J. Kožisek, J.G. Diaz, M. Hvastijova, L. Jager, Acta Crystallogr., Sect. C 53 (1997) 703). The crystal structure of the first two compounds consists of [Cu(NO2NCN)2L4] units, in which the central CuII atoms are pseudo-octahedrally coordinated by six nitrogen atoms. Four of them, in equatorial planes, originate from meiz molecules and two, in axial positions, are nitrile nitrogens from the NO2NCN− anions. Influence of hydrogen bonds on equatorial–axial bond length correlation was ascertained. In the ESR spectra of the [Cu(NO2NCN)2L4] compounds copper hyperfine splitting is resolved. For all complexes, weak lines corresponding to the ΔMs=2 transitions appear. The spectrum of [Cu(NO2NCN)2(iz)4] in frozen methanolic solution shows 16-fold nitrogen splitting of the perpendicular band.

Phosphonium diylides afford a general synthetic method for numerous α,β-unsaturated functions, the double bond being di- or trisubstituted. The diamino-phosphonium diylides, obtained in the case of stabilized ones by a new variation of the Staudinger reaction, are also interesting tools in synthesis because they allow access to, for example ketenimines, phosphorus guanidines or triazaphosphinimines.

The crystal structure of [Cu(NCS)(C10H8N2)2][C(CN)3] is composed of discrete [Cu(bipy)2(NCS)]+ cations and [C(CN)3]− anions (bipy is 2,2′-bipyridine). The coordination polyhedron of CuII is a distorted trigonal bipyramid with a {CuN5} chromophore.

Background Group 5 allergens represent major grass pollen allergens because of their high sensitization indices. The identification of T-cell epitopes of these allergens is a prerequisite for the design of immunotherapeutic strategies based on peptide vaccination or modified allergens with conserved T-cell epitopes. Objective This study was undertaken to determine T-cell epitopes on Phl p 5 major pollen allergen of timothy grass (Phleum pratense). Methods T-cell lines (TCLs) and T-cell clones (TCCs), specific to Phl p 5, were established from the peripheral blood of 18 patients allergic to grass pollen. All TCCs were mapped for epitope specificities using 178 overlapping dodecapeptides representing the primary structures of two isoforms of Phl p 5 (Phl p 5a and Phl p 5b). Phenotype and cytokine production profiles of TCCs were tested. Selected TCCs were analysed for HLA class II restriction. Results A total of 82 TCCs were isolated. All TCCs displayed the helper cell (TH) phenotype. Their reactivity with two recombinant expressed isoforms of Phl p 5a and Phl p 5b was heterogeneous. The epitope specificity of the TCCs was then revealed. Nineteen T-cell epitopes could be identified on Phl p 5. Eighty-one percent of mapped TCCs recognized three T-cell reactive regions on the Phl p 5 allergen. Some TCCs were reactive with isoepitopes presenting on Phl p 5a as well as Phl p 5b. Allergen-specific stimulation induced a TH0-like type of cytokine production in 25 of 50 TCCs. Almost all TCCs secreted high concentrations of interleukin-13. Conclusion Phl p 5, a major grass pollen allergen, contains several T-cell epitopes. Some epitope regions were recognized by several patients. Epitope recognition pattern could not be correlated with special HLA class II haplotypes. T-cell stimulating isoepitopes were found at corresponding regions of Phl p 5a and Phl p 5b isoforms.

Coordinated pyrazoles exhibit a nucleophilic addition to the cyanate ligand inside the transition metal coordination sphere and new chelate complexes are formed; the new anionic ligand of the carbamoylpyrazolate type can be released. The conditions for such an addition were studied and established by selecting various central atoms and different N-donor heterocyclic ligands. Some non-linear pseudohalides, namely N(CN)2−, C(CN)3− and ONC(CN)2−, are also capable of such reactions but the addition proceeds under different conditions due to different electronic and steric requirements. A new type of isomerism—coligand isomerism—has been discovered: one isomer is the usual complex of the [MX2(pzt)2] type (pzt, pyrazole-type ligand) whereas in the second isomer [M(pzt·X)2] a new anionic chelating ligand formed by nucleophilic addition is present. Another type of nucleophilic addition, reaction of methanol with the N(CN)2− specifically in the coordination sphere of CuII leads to the formation of a six-membered metallacycle. Nucleophilic addition of methanol to the ONC(CN)2− anion in the transition metal coordination sphere results in formation of a five-membered metallacycle. All nucleophilic additions studied have a common feature in a coordinative activation of the carbon β-site of the pseudohalides changing its hybridization and providing an unsaturated valency for a nucleophilic attack.

Complexes of the type [M{N(O)C(CN)2}(PPh3)n] (M = CuI, AgI, n = 2, 3) were synthesized by metathesis of K[N(O)C(CN)2] and [M(NO3)(PPh3)n]. The complexes were characterized by 13C-, 31P-NMR and IR spectroscopy and elemental analyses. The crystal structures of [M{N(O)C(CN)2}(PPh3)2]2 (M = CuI, AgI) have been determined by X-ray diffraction. Depending on the metal atom in the complexes [M{N(O)C(CN)2}(PPh3)3] the ionic ligand is coordinated via the central nitrogen (copper) or the oxygen atom (silver). In addition the two copper and silver complexes [M{N(O)C(CN)2}(PPh3)2]2 are not isostructural but have quite different structures. For M = Cu the two copper atoms are doubly bridged by two NCCN sequences, forming an approximately planar Cu(NCCN)2Cu ring. On the other hand, in the homologous silver derivative the metal atoms are also doubly bridged, but by two NO groups, thus forming a planar six-membered ring.