Chloride/sulphate exchange on anion resins. kinetic investigation,viii. influence of some physico-chemical properties of the resins

Experimental exchange rates for Cl^-/SO⁼₄ exchange on strictly comparable anion resins in 0.006N solution confirm the unfavorable correlation between kinetics and selectivity.Furthermore, evaluation of the influence of other physico-chemical properties of the resins (i.e., nature of matrix, type of amine, etc) seems to support the hypothesis that chemical interactions, and not only diffusional effects, in the resin phase play a leading role on rate control.     

Salivary Proteome Changes in Response to Acute Psychological Stress Due to an Oral Exam Simulation in University Students: Effect of an Olfactory Stimulus

The autonomic nervous system (ANS) plays a crucial role both in acute and chronic psychological stress eliciting changes in many local and systemic physiological and biochemical processes. Salivary secretion is also regulated by ANS. In this study, we explored salivary proteome changes produced in thirty-eight University students by a test stress, which simulated an oral exam. Students underwent a relaxation phase followed by the stress test during which an electrocardiogram was recorded. To evaluate the effect of an olfactory stimulus, half of the students were exposed to a pleasant odor diffused in the room throughout the whole session. Saliva samples were collected after the relaxation phase (T0) and the stress test (T1). State anxiety was also evaluated at T0 and T1. Salivary proteins were separated by two-dimensional electrophoresis, and patterns at different times were compared. Spots differentially expressed were trypsin digested and identified by mass spectrometry. Western blot analysis was used to validate proteomic results. Anxiety scores and heart rate changes indicated that the fake exam induced anxiety. Significant changes of α-amylase, polymeric immunoglobulin receptor (PIGR), and immunoglobulin α chain (IGHA) secretion were observed after the stress test was performed in the two conditions. Moreover, the presence of pleasant odor reduced the acute social stress affecting salivary proteome changes. Therefore, saliva proteomic analysis was a useful approach to evaluate the rapid responses associated to an acute stress test also highlighting known biomarkers.     

Effect of weaning status on animal performance and meat quality of Rubia Gallega calves

The effect of weaning calves at different ages (NW = not weaned, W5 = 5.5 months old and W2 = weaned after being born and then fed with natural Holstein Friesian milk until 2 months old), on animal performance and carcass and Longissimus thoracis muscle quality, was studied in 36 eight month-old Rubia Gallega calves. Feed ingestions, weight gains, slaughter (SW) and carcass weights (CW), carcass conformation and fat scores, and meat characteristics (24 hours postmortem): colour, pH, water holding capacity, chemical composition and texture (Warner Bratzler (WB) test, sensory panel), were studied. NW calves showed the highest SW and CW (P < 0.001). Yellowness (b*), redness (a*) and chroma (C*) were higher in NW than W2 calves (P < 0.05). Shear firmness was higher in W2 than in NW and W5 veal. W2 veal was less elastic (P < 0.05), tender (P < 0.05) and juicy (P < 0.01) than NW and W5 veal.     

Effect of fat-enriched diets on rabbit meat fatty acid composition

The effects of beef tallow-, soya and sunflower olein- and soya bean oil-enriched (3%) diets on the chemical and fatty acid composition of total, a polar and polar lipids of rabbit meat have been studied. No significant differences (P > 0.05) in the meat chemical composition were observed between groups. However, a large effect of the diet on the total and apolar lipid fatty acids was found, with C18:1 and C18:2 the most affected fatty acids. The influence of the diets on the fatty acids of the polar fraction was less marked. It is concluded that the enrichment of the rabbit diet with either soya and sunflower oleins or soya bean oil allows the production of rabbit meat with a higher unsaturation degree than is obtained by using conventional diets, which constitutes an important nutritional benefit to the human being.     

Determination of fermentative volatile compounds in aged red wines by near infrared spectroscopy

The purpose of this work was to study the possibility of determination of fermentative volatile compounds in aged red wines using NIR spectroscopy. To achieve this, 240 wines belonging to different geographic zones and elaborated with one or two varieties were analyzed. The volatile compounds were quantified by SBSE-GC–MS. Spectra obtained by NIR were co-related with these values using partial least square (PLS) regression. Calibration and validation statistics showed the quality of the model, after all when is done separately for each of the four geographic zones, and in the case of wines elaborated with two varieties. Consequently, near infrared spectroscopy can be used as an easy and rapid tool to determine fermentative volatile compounds in aged red wines.     

Thermophiles as Potential Source of Novel Endotoxin Antagonists: the Full Structure and Bioactivity of theLipo‐oligosaccharide from Thermomonas hydrothermalis

Thermomonas hydrothermalis is a Gram‐negative thermophilic bacterium that is able to live at 50 °C. This ability is attributed to chemical modifications, involving those to bacterial cell‐wall components, such as proteins and (glyco)lipids. As the main component of the outer membrane of Gram‐negative bacteria, lipopolysaccharides (LPSs) are exposed to the environment, thus they can undergo structural chemical changes to allow thermophilic bacteria to live at their optimal growth temperature. Furthermore, as one of the major target of the eukaryotic innate immune system, LPS elicits host immune response in a structure‐dependent mode; thus the uncommon chemical features of thermophilic bacterial LPSs might exert a different biological action on the innate immune system—an antagonistic effect, as shown in studies of LPS structure–activity relationship in the ongoing research into antagonist LPS candidates. Here, we report the complete structural and biological activity analysis of the lipo‐oligosaccharide isolated from Thermomonas hydrothermalis, achieved by a multidisciplinary approach (chemical analysis, NMR, MALDI MS and cellular immunology). We demonstrate a tricky and interesting structure combined with a very interesting effect on human innate immunity.     

Discovery of a Short‐Chain Dehydrogenase from Catharanthus roseus that Produces a New Monoterpene Indole Alkaloid

Plant monoterpene indole alkaloids, a large class of natural products, derive from the biosynthetic intermediate strictosidine aglycone. Strictosidine aglycone, which can exist as a variety of isomers, can be reduced to form numerous different structures. We have discovered a short‐chain alcohol dehydrogenase (SDR) from plant producers of monoterpene indole alkaloids (Catharanthus roseus and Rauvolfia serpentina) that reduce strictosidine aglycone and produce an alkaloid that does not correspond to any previously reported compound. Here we report the structural characterization of this product, which we have named vitrosamine, as well as the crystal structure of the SDR. This discovery highlights the structural versatility of the strictosidine aglycone biosynthetic intermediate and expands the range of enzymatic reactions that SDRs can catalyse. This discovery further highlights how a sequence‐based gene mining discovery approach in plants can reveal cryptic chemistry that would not be uncovered by classical natural product chemistry approaches.     

Extraction and characterization of hydroxyapatite-based materials from grey triggerfish skin and black scabbardfish bones

The conversion of food industry by-products to compounds with high added value is nowadays a significant topic, for social, environmental, and economic reasons. In this paper, calcium phosphate-based materials were obtained from black scabbardfish (Aphanopus carbo) bones and grey triggerfish (Balistes capriscus) skin, which are two of the most abundant fish by-products of Madeira Island. Different calcination temperatures between 400 and 1000°C were employed. Materials obtained from calcination of bones of black scabbard fish were composed by homogeneous mixtures of hydroxyapatite (Ca₁₀(PO4)₆(OH)₂, HAp) and β-tricalcium phosphate (β-Ca₃(PO₄)₂, β-TCP). Because of the high biocompatibility of HAp and the good resorbability of β-TCP, these natural biphasic materials could be very relevant in the field of biomaterials, as bone grafts. The ratio between HAp and β-TCP in the biphasic compound was dependent on the calcination temperature. Differently, the material obtained from skin of grey triggerfish contained HAp as the main phase, together with small amounts of other mineral phases, such as halite and rhenanite, which are known to enhance osteogenesis when used as bone substitutes. In both cases, the increase of calcination temperature led to an increase in the particles size with a consequent decrease in their specific surface area. These results demonstrate that from the fish by-products of the most consumed fishes in Madeira Island it is possible to obtain bioceramic materials with tunable composition and particle morphology, which could be promising materials for the biomedical field.     

High Performance, Low-Dose Radiography Systems for Space and Remote Site Applications

Medical imaging applications using X- and gamma-rays have reached outstanding levels of complexity and performance, thanks to technology achievements in the fields of radiography, tomography and high resolution synchrotron devices. The operability of the related instrumentation resides in the availability of highly qualified specialists, as well as of medical doctors for diagnoses and treatment. This is a problem for personnel working in difficult ambient conditions as can be found in remote sites like Arctica, Antarctica and under-populated, desolated or mountainous regions on Earth. Astronauts, during long permanence at the Space Station or on future mission to Mars are potentially subject to risks such as traumas, fractures or diseases which would require semi-automated, easy-to-handle application of X-ray radiographic devices. For this purpose, the possible use of imaging instrumentation based on solid state detectors is discussed with special regard to CdZnTe pixel devices, now available with sub-mm resolution. The use of these semiconductor detectors will also allow to perform image diagnostics at much lower doses compared to the current plate-based radiographic techniques.