Quantitative determination of wine highly volatile sulfur compounds by using automated headspace solid-phase microextraction and gas chromatography-pulsed flame photometric detection. Critical study and optimization of a new procedure.

The quantitative determination of wine volatile sulfur compounds by automated headspace solid-phase microextraction (HS-SPME) with a carboxen-polydimethylsiloxane (CAR-PDMS) fiber and subsequent gas chromatography-pulsed flame photometric detection (GC-PFPD) has been evaluated. The direct extraction of the sulfur compounds in 5 ml of wine has been found to suffer from matrix effects and short linear ranges, problems which could not be solved by the use of different internal standards or by multiple headspace SPME. These problems were attributed to saturation of the fiber and to competitive effects between analytes, internal standards and other wine volatiles.

[Acute toxoplasmosis: clinical and laboratory data in eleven patients].

Introduction: The clinical and laboratory data of immunocompetent patients with acute toxoplasmosis (AT) are described.

Patients And Methods: We performed a retrospective study of patients with AT attended between 1996 and 2004. Diagnostic criteria consisted of compatible clinical findings (generalized and cervical lymphadenopathies) and specific serology against Toxoplasma gondii (high IgG and IgM and/or reactive IgA).

[Congenital Chagas disease: experience in the Hospital de Niños, Ricardo Gutiérrez, Buenos Aires, Argentina].

Epidemiological, clinical, diagnostic, and therapeutic data from children who were born to mothers infected with T. cruzi who came to our hospital are presented. In addition, we exhibit the preliminary results of a technique that detects the anti F2/3 antibodies: these would be able to confirm the cure earlier than conventional serology.

Examining the role of surfactant packing in phase transformations of periodic templated silica/surfactant composites.

In this work, we examine the role of curvature and surfactant packing in controlling the structure of periodic silica/surfactant composites by driving such materials through a transformation from a hexagonal to a lamellar phase. We focus on how the interplay of desired packing and volume constraints dictates the resulting structures. In general, surfactants expand in a complex way upon heating, and this can cause a change in the optimal packing geometry.

Mitochondrial DNA content of human spermatozoa.

Sperm mitochondria play an important role in spermatozoa because of the high ATP demand of these cells. Different mitochondrial DNA (mtDNA) mutations and haplogroups influence sperm function. The mtDNA dose also contributes to genetic variability and pathology in different tissues and organs, but nothing is known about its relevance in the performance of spermatozoa.