Claudia M. Gómez-Gutiérrez

Marine edible algae as disease preventers.

As modern lifestyles and new feeding habits settle in the world, noncommunicable diseases (NCDs) have evolved to be major causes of disability in developing as well as developed countries. As a concomitant effect, there is a growing interest in natural, healthy food and an increasing awareness of risk factors and determinants of disease. This chapter describes some nutritional facts about seaweeds, which have been used as food since ancient times in China, Japan, Egypt, and India and comments on the potential utilization of marine algae as functional foods. This concept and the description of metabolic syndrome are used as a basis to comprehension of seaweeds against two dreadful illnesses of our times: high blood pressure and cancer.

Solvothermal synthesis of nickel-tungsten sulfides for 2-propanol dehydration.

The bimetallic nickel-tungsten catalysts were prepared via solvothermal method. The X-ray Diffractometer (XRD) analysis revealed that the corresponding peaks at 14°, 34°, and 58° were for tungsten disulfide (WS2 ) hexagonal phase. The catalysts displayed different crystalline phase with nickel addition, and as an effect the WS2 surface area decreased from 74.7 to 2.0 m(2) g(--1) . In this sense, high-resolution transmission electron microscopy (HRTEM) showed the layers set in direction (002) with an onion-like morphology, and in the center of the particles there is a large amount of nickel contained with 6-8 layers covering it. The catalytic dehydration of 2-propanol was selective to propene in 100% at 250 °C for the sample with 0.7 of atomic ratio of Ni/Ni + W.

Study of the morphology of ZnS thin films deposited on different substrates via chemical bath deposition

In this work, the influence of substrate on the morphology of ZnS thin films by chemical bath deposition is studied. The materials used were zinc acetate, tri-sodium citrate, thiourea, and ammonium hydroxide/ammonium chloride solution. The growth of ZnS thin films on different substrates showed a large variation on the surface, presenting a poor growth on SiO2 and HfO2 substrates. The thin films on ITO substrate presented a uniform and compact growth without pinholes. The optical properties showed a transmittance of about 85% in the visible range of 300-800 nm with band gap of 3.7 eV.

Uptake and biochemical response to B[a]P in the sea anemone Anthopleura elegantissima

In order to evaluate the effects of benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon (PAH) in the sea anemone Anthopleura elegantissima at the biochemical level. NADPH cytochrome P450 reductase and cytochrome P450 were assayed in A. elegantissima under toxicant. One toxicity test was performed with 75 organisms distributed in 5 groups. Animals in groups G1, G2 and G3 were given increasing B[a]P. Two groups named GC and GS were used as controls. GC was treated with seawater and GS was treated with acetone. After 72 h of exposure, enzymatic activities were determined. Microsomes were isolated from the columnar tissue and exposed in vitro to the toxicant in order to explore their ability to incorporate B[a]P. Basal activity for this enzyme was 1.69 ± 0.18 (Mean ± standard deviation) nmol cyt C red min−1 mg−1 and there was no significant effect in GS organisms compared to GC organisms. Significant increases were observed in NADPH cytochrome P450 reductase in G3 organisms. In this group, the enzyme activity was 3.53 ± 0.40 nmol cyt C red min−1 mg−1. For cytochrome P450 content, a gradual increase was observed in organisms in groups G1 to G3. Basal content was 10.25 ± 0.49 pmol mg−1 microsomal protein. For G3 animals, P450 content was 27.51 ± 0.32 pmol mg−1 microsomal. For the test in vitro, it was found that microsomes isolated from G2 and G3 had the capacity to incorporate this substance when exposed to B[a]P at a level of 4 μ M in the surrounding medium. Spectrum recorded from 350 to 450 nm after a 40-min exposure for these groups showed significant difference from spectra obtained for microsomes in GC, GS and G1. It was concluded that the capacity to increase NADPH cytochrome P450 reductase activity as well as to increase NADPH cytochrome P450 reductase activity as well as to increase P450 content shows the ability of A. elegantissima to induce a mixed function oxidase activity in the presence of B[a]P.

Effect of polycyclic aromatic hydrocarbons on the pallial fluid buffering capacity of the marine mussel, Mytilus galloprovincialis

Pallial fluid buffering capacity of the sea mussel Mytilus galloprovincialis was investigated to establish the potential of this biological parameter to serve as a biomarker. Four groups of 15 animals were used in a 72-h toxicity test. Group 1, the aerobic control group, was placed in a filtered aerated natural seawater aquarium. Groups 2-4 were subjected to hypoxic conditions by removal from water after animals were injected with a single dose of the following: group 2 (anaerobic control) was administered 10 microl of UV-treated filtered natural seawater; group 3 (anaerobic solvent control) was injected with 10 microl of acetonitrile and group 4 (PAH exposed group) with 10 microl of 2 mM anthracene. Pallial fluid was taken from all the animals following seawater immersion or air exposure. Pallial fluid from each individual was extracted, adjusted to pH 5.0 and titrated with NaOH until reaching pH 6.0. The buffering capacity index (beta), defined as the amount of mu equivalents of NaOH needed to change in one unit the pH of a 5-ml sample of pallial fluid, was calculated for each group. Values were: for group 1, beta = 3.17 (+/- 0.782); for group 2, beta=15.713 (+/-2.992); group 3 was beta=18.124 (+/-2.288); and group 4 was beta=28.109 (+/-11.398). The statistically significant increase (P<0.05) in group 4 compared with the other groups indicates that the buffering capacity index (beta) is a worthy biological parameter to be further explored as a biomarker for ecotoxicological monitoring programs. The increase in buffering capacity is discussed and a biochemical link between anaerobic metabolism and the exposure to PAH is suggested to explain changes of this biological parameter.