Nachweis und Bestimmung des Eisens

Ohne Zusammenfassung     

Modulation of humoral immune response to oral BCG vaccination by Mycobacterium bovis BCG Moreau Rio de Janeiro (RDJ) in healthy adults

Background  

Oral administration of BCG was the route initially used by Calmette and Guérin, but was replaced by intradermal administration in virtually all countries after the Lubeck accident. However, Brazil continued to administer oral BCG Moreau RDJ, which was maintained until the mid-1970s when it was substituted by the intradermal route. Although BCG vaccination has been used in humans since 1921, little is known of the induced immune response. The aim of this study was to analyse immunological responses after oral vaccination with M. bovis BCG Moreau RDJ.     

Effect of substitution of Ce on superconducting properties of Bi1.7Pb0.3Sr2Ca2−x Ce x Cu3O10+δ system

We have investigated the superconducting properties of the Bi_1.7 Pb_0.3Sr₂Ca_2−xCe _x Cu₃O_10+δ system with x=0.00, 0.02, 0.04, 0.08 and 0.1 by X-ray diffraction and magnetic susceptibility. The substitution of Ce for Ca has been found to drastically change the superconducting properties of the system. X-ray diffraction studies on these compounds indicate decrease in the c-parameter with increased substitution of Ce at Ca site and volume fraction of high T _c (2 : 2 : 2 : 3) phase decreases and low T _c phase increases. The magnetic susceptibility of this compound shows that the diamagnetic on set superconducting transition temperature (onset) varies from 109 K to 51 K for x=0.00, 0.02, 0.04, 0.08 and 0.1. These results suggest the possible existence of Ce in a tetravalent state rather than a trivalent state in this system; that is, Ca²⁺ → Ce⁴⁺ replacement changes the hole carrier concentration. Hole filling is the cause of lowering T _c of the system.     

Determination of the orbital polarization in YTiO3 by using soft X-ray linear dichroism

We report measurements of linear dichroism in x-ray absorption at Ti L(2,3) edges of a Mott-insulating ferromagnet YTiO3, where orbital ordering occurs in the triply degenerate Ti 3d t(2g) states. Dichroic spectra and their integrated intensities are obtained for the incident electric field with polarizations parallel to a, b, and c axes. The comparison of the spectra with atomic multiplet calculations removes the ambiguity about the orbital polarization, i.e., the relative weights of |xy>, |yz>, and |zx> orbits, which are crucial for the origin of ferromagnetism. The result is consistent with the previous analysis of nuclear magnetic resonance in the Mizokawa-Fujimori scheme.     

Relationship between retention behaviour and molecular structure of alkanes in reversed phase high performance liquid chromatography

Summary The retention data of 54 alkanes C₅-C₁₁ with different degrees of branching were determined in order to study the relationship between retention behaviour and the structure of alkanes by reversed phase high-performance liquid chromatography. The structural parameters influencing the retention of alkanes are described. The connectivity index was employed to correlate the structures of alkanes with their retention data.

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Beziehung zwischen Retentionsverhalten und Molekularstruktur von Alkanen in der Umkehrphasen-HPLC

Zusammenfassung Zur Untersuchung dieser Beziehung wurden die Retentionsdaten von 54 Alkanen (C₅-C₁₁) mit verschiedenem Verzweigungsgrad bestimmt. Die Strukturparameter, die die Retention beeinflussen, werden diskutiert. Zur Korrelation der Strukturen mit ihren Retentionsdaten wird das Indexinkrement benutzt.

     

Determination of the concentration in the ion-exchanger phase

Summary The interstitial volume of the exchanger bed and the volume of the solution attached to the exchanger particles, which are necessary for the determination of the sample concentration in the ion exchanger phase, were determined by deriving equations based on Donnan's distribution. Some of the results obtained by this new method were confirmed by comparison with values by alternative methods.

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Konzentrationsbestimmung in der Ionenaustauscher-Phase

Zusammenfassung Das Einlagerungsvolumen des Austauscherbettes und das Volumen der an den Austauscherteilchen haftenden Lösung, die zur Bestimmung der Probekonzentration in der Austauscherphase erforderlich sind, wurden durch Gleichungen erfaßt, die aus der Donnanschen Verteilung abgeleitet wurden. Einige nach diesem Verfahren erhaltene Ergebnisse wurden durch Vergleich mit nach anderen Methoden erhaltenen bestätigt.

     

Facile synthesis of Fe3O4 nanoparticles by reduction phase transformation from γ-Fe2O3 nanoparticles in organic solvent

A phase transformation induced by the reduction of as-synthesized γ-maghemite (γ-Fe₂O₃) nanoparticles was performed in solution by exploiting the reservoir of reduction gas (CO) generated from the incomplete combustion reaction of organic substances in the reactor. Results from X-ray diffraction, color indicator, and magnetic analysis using a SQUID strongly support this phase transformation. Based on this route, monodisperse magnetite (Fe₃O₄) nanoparticles were simply produced in the range from 260 to 300 °C. Almost all aspects of the original γ-Fe₂O₃ nanoparticles, such as shape, size, and monodispersity, were maintained in the produced Fe₃O₄ nanoparticles.     

New Developments in Photoinitiators

New developments of photoinitiators are the base for the further extension of the radiation curing technology. Three different approaches are presented: The optimized combination of a bisacylphosphine oxide photoinitiator with a suitable stabilizer package allows the UV curing of clear coatings with an excellent performance in outdoor use. The design of new oxime ester derivatives allowed the introduction of a new tailor-made photoinitiator for color filter resists applications that considerably improves the color quality of the color filter. A novel photoinitiator class capable of releasing strong amine bases opens new opportunities for expanding radiation curing into resins types that crosslink by base-catalyzed processes.