High molecular gas fractions in normal massive star-forming galaxies in the young Universe.

Stars form from cold molecular interstellar gas. As this is relatively rare in the local Universe, galaxies like the Milky Way form only a few new stars per year. Typical massive galaxies in the distant Universe formed stars an order of magnitude more rapidly. Unless star formation was significantly more efficient, this difference suggests that young galaxies were much more molecular-gas rich. Molecular gas observations in the distant Universe have so far largely been restricted to very luminous, rare objects, including mergers and quasars, and accordingly we do not yet have a clear idea about the gas content of more normal (albeit massive) galaxies. Here we report the results of a survey of molecular gas in samples of typical massive-star-forming galaxies at mean redshifts of about 1.2 and 2.3, when the Universe was respectively 40% and 24% of its current age. Our measurements reveal that distant star forming galaxies were indeed gas rich, and that the star formation efficiency is not strongly dependent on cosmic epoch. The average fraction of cold gas relative to total galaxy baryonic mass at z = 2.3 and z = 1.2 is respectively about 44% and 34%, three to ten times higher than in today's massive spiral galaxies. The slow decrease between z approximately 2 and z approximately 1 probably requires a mechanism of semi-continuous replenishment of fresh gas to the young galaxies.

Intense pulsed light: results in chronic dry eye syndrome after LASIK. / Luz pulsada intensa: resultados en ojo seco crónico tras LASIK.

A report is presented on the visual and clinical results from a retrospective case series of patients with chronic, evaporative, dry eye syndrome (DES), after refractive surgery, and treated with intense pulsed light treatment (IPL). Four sessions were performed, and the Ocular Surface Disease Index (OSDI) questionnaire was completed before initiating treatment and after the last session. Pre- and post-treatment data included: visual acuity (VA), refraction, clinical evaluation (DEWS severity grading, and Oxford corneal staining), and Orbscan topography. Twenty eyes were treated and the following data recorded: SchirmerI 14.7±5.6; 15.6±3.4mm, tear breakup time (TBUT) 3.4±1.6; 5.1±1.2s (P>.003), DEWS 3.4±0.5; 1.6±0.7 (P<.003), Oxford grade 0.8±0.77; 0.4±0.75 (P>.003), VA 0.67±0.26; 0.90±0.15 (P<.0001), best corrected VA 0.83±0.18; 0.92±0.14 (P>.003), spherical equivalent -0.31±0.6; -0.08±0.38D (P>.003), OSDI 34±16; 28±11.0 points (P>.003), frequency artificial tear use 3.4±2.0; 2.5±1.9 times/day (P>.03). A significant clinical and visual improvement was observed, together with a decreased frequency in artificial tear use, in LASIK patients with chronic DES after IPL treatment.

Plant extracts as natural modulators of gut microbiota community structure and functionality.

The main objective of this work was to evaluate the effect that several plant extracts (currently sold as functional ingredients) have on gut microbiota community structure and functionality. Plant extracts were submitted to an in vitro digestion and fecal fermentation. Overall, plant extracts showed a marked inhibitory activity when compared to basal conditions. However, they also favored the growth of some bacteria such as Coprococcus and Butyricimonas, two butyrate producers. Especially interesting was tea extract which inhibited the growth of the genus Escherichia/Shigella, known to involve species related with gastrointestinal disorders. Additionally, tea extract increased the growth of Faecalibacterium, a known butyrate producer. Regarding short chain fatty acids production, while plant extracts reduced acetate production, butyrate was increased for most samples, especially tea extract. Propionate production was less affected in comparison with basal conditions. Fermentation by gut microbiota also modified the antioxidant capacity (assessed via DPPH, FRAP and Folin-Ciocalteu methods).

Relationship of quality parameters, antioxidant capacity and total phenolic content of EVOO with ripening state and olive variety.

The aim of this work was to study the evolution of quality parameters, fatty acid composition, antioxidant capacity and total phenolic content of olive oil obtained from two olive varieties (Manzanilla and Picual) with different maturation. Antioxidant capacity and total phenolic content were measured after submitting the olive oil to in vitro digestion and fermentation to mimic physiological conditions. Quality parameters were always within the legal limits to be called "Extra Virgin Olive Oil". Antioxidant capacity, total phenolic content, saturated fatty acids and monounsaturated fatty acids (MUFA) decreased along maturation, whereas polyunsaturated fatty acids (PUFA) increased in both varieties. Manzanilla showed higher PUFA content, whereas Picual had higher MUFA concentration, antioxidant capacity and total phenolic content. The fermented fraction of olive oil displayed a higher antioxidant capacity. Finally, the statistical approach demonstrated that the type of variety is more important than collection date regarding fatty acid composition and antioxidant capacity.

Gas phase Elemental abundances in Molecular cloudS (GEMS) II. On the quest for the sulphur reservoir in molecular clouds: the H2S case.

CONTEXT: Sulphur is one of the most abundant elements in the Universe. Surprisingly, sulphuretted molecules are not as abundant as expected in the interstellar medium and the identity of the main sulphur reservoir is still an open question. AIMS: Our goal is to investigate the H2S chemistry in dark clouds, as this stable molecule is a potential sulphur reservoir. METHODS: Using millimeter observations of CS, SO, H2S, and their isotopologues, we determine the physical conditions and H2S abundances along the cores TMC 1-C, TMC 1-CP, and Barnard 1b. The gas-grain model Nautilus is used to model the sulphur chemistry and explore the impact of photo-desorption and chemical desorption on the H2S abundance. RESULTS: Our modeling shows that chemical desorption is the main source of gas-phase H2S in dark cores. The measured H2S abundance can only be fitted if we assume that the chemical desorption rate decreases by more than a factor of 10 when n H > 2 × 104. This change in the desorption rate is consistent with the formation of thick H2O and CO ice mantles on grain surfaces. The observed SO and H2S abundances are in good agreement with our predictions adopting an undepleted value of the sulphur abundance. However, the CS abundance is overestimated by a factor of 5 - 10. Along the three cores, atomic S is predicted to be the main sulphur reservoir. CONCLUSIONS: The gaseous H2S abundance is well reproduced, assuming undepleted sulphur abundance and chemical desorption as the main source of H2S. The behavior of the observed H2S abundance suggests a changing desorption efficiency, which would probe the snowline in these cold cores. Our model, however, highly overestimates the observed gas-phase CS abundance. Given the uncertainty in the sulphur chemistry, we can only conclude that our data are consistent with a cosmic elemental S abundance with an uncertainty of a factor of 10.

Dynamics of cluster-forming hub-filament systems: The case of the high-mass star-forming complex Monoceros R2.

CONTEXT: High-mass stars and star clusters commonly form within hub-filament systems. Monoceros R2 (hereafter Mon R2), at a distance of 830 pc, harbors one of the closest such systems, making it an excellent target for case studies. AIMS: We investigate the morphology, stability and dynamical properties of the Mon R2 hub-filament system. METHODS: We employ observations of the 13CO and C18O 1→0 and 2→1 lines obtained with the IRAM-30m telescope. We also use H2 column density maps derived from Herschel dust emission observations. RESULTS: We identified the filamentary network in Mon R2 with the DisPerSE algorithm and characterized the individual filaments as either main (converging into the hub) or secondary (converging to a main filament) filaments. The main filaments have line masses of 30-100 M ⊙ pc-1 and show signs of fragmentation, while the secondary filaments have line masses of 12-60 M ⊙ pc-1 and show fragmentation only sporadically. In the context of Ostriker's hydrostatic filament model, the main filaments are thermally supercritical. If non-thermal motions are included, most of them are trans-critical. Most of the secondary filaments are roughly transcritical regardless of whether non-thermal motions are included or not. From the morphology and kinematics of the main filaments, we estimate a mass accretion rate of 10-4-10-3 M ⊙ yr-1 into the central hub. The secondary filaments accrete into the main filaments with a rate of 0.1-0.4×10-4 M ⊙ yr-1. The main filaments extend into the central hub. Their velocity gradients increase towards the hub, suggesting acceleration of the gas.We estimate that with the observed infall velocity, the mass-doubling time of the hub is ~ 2:5 Myr, ten times larger than the free-fall time, suggesting a dynamically old region. These timescales are comparable with the chemical age of the Hii region. Inside the hub, the main filaments show a ring- or a spiral-like morphology that exhibits rotation and infall motions. One possible explanation for the morphology is that gas is falling into the central cluster following a spiral-like pattern.

Gas phase Elemental abundances in Molecular cloudS (GEMS): I. The prototypical dark cloud TMC 1.

GEMS is an IRAM 30m Large Program whose aim is determining the elemental depletions and the ionization fraction in a set of prototypical star-forming regions. This paper presents the first results from the prototypical dark cloud TMC 1. Extensive millimeter observations have been carried out with the IRAM 30m telescope (3 mm and 2 mm) and the 40m Yebes telescope (1.3 cm and 7 mm) to determine the fractional abundances of CO, HCO+, HCN, CS, SO, HCS+, and N2H+ in three cuts which intersect the dense filament at the well-known positions TMC 1-CP, TMC 1-NH3, and TMC 1-C, covering a visual extinction range from A V ~ 3 to ~20 mag. Two phases with differentiated chemistry can be distinguished: i) the translucent envelope with molecular hydrogen densities of 1-5×103 cm-3; and ii) the dense phase, located at A V > 10 mag, with molecular hydrogen densities >104 cm-3. Observations and modeling show that the gas phase abundances of C and O progressively decrease along the C+/C/CO transition zone (A V ~ 3 mag) where C/H ~ 8×10-5 and C/O~0.8-1, until the beginning of the dense phase at A V ~ 10 mag. This is consistent with the grain temperatures being below the CO evaporation temperature in this region. In the case of sulfur, a strong depletion should occur before the translucent phase where we estimate a S/H ~ (0.4 - 2.2) ×10-6, an abundance ~7-40 times lower than the solar value. A second strong depletion must be present during the formation of the thick icy mantles to achieve the values of S/H measured in the dense cold cores (S/H ~8×10-8). Based on our chemical modeling, we constrain the value of ζ H2 to ~ (0.5 - 1.8) ×10-16 s-1 in the translucent cloud.

Towards an improved global antioxidant response method (GAR+): Physiological-resembling in vitro digestion-fermentation method.

The antioxidant capacity of food influences its shelf life and human health. To determine this parameter, the corresponding antioxidant species must first be extracted. Current methods don't adequately address this issue since they rely on extractions with organic solvents or on in vitro digestion without a subsequent fermentation. We present an improved protocol to determine the global antioxidant response of foods (GAR+) including both in vitro digestion and fermentation. All samples should be fermented with the same fresh faecal inoculum in order to decrease variability. In addition, the use of a pool of faeces from healthy donors is strongly recommended to improve repeatability. Although most antioxidant capacity is achieved after digestion, in some foods fermentation plays a role. Thus, the GAR+ method provides reliable values of the antioxidant capacity of foods that are closer to their in vivo activity by including the effects of gut microbiota over non-digested nutrients.

Towards an improved Global Antioxidant Response method (GAR+): Physiological-resembling in vitro antioxidant capacity methods.

Many methods have been developed to measure the antioxidant capacity of foods under non physiological-relevant conditions. In this study, three methods (TEACOH, GEACRED and TEACAAPH) are developed to measure antioxidant capacity at physiological pH, using indigo carmine as a redox dye. TEACOH and TEACAAPH determine foodstuffs' scavenging capacity against hydroxyl (OH) and AAPH radicals, while the third method measures the global reducing capacity of the sample. The results obtained for commercial teas, commercial beverages containing tea as the main ingredient and different solid foods (spinach, onion, salami, etc.) were compared with well-established protocols. The new methods demonstrated good linearity-reproducibility, providing reliable data about the antioxidant capacity of foods under physiological-resembling conditions. The new methods were also useful for evaluating the antioxidant capacity of human plasma after acute intake of tea. The physiological-resembling conditions of these assays and the use of absorbance readings make them suitable for application by any laboratory.

Effect of brewing time and temperature on antioxidant capacity and phenols of white tea: Relationship with sensory properties.

White tea is highly consumed due to its sensory properties and health benefits, although most scientific reports don't include the analysis of both properties. Therefore, the objective of the present study was to unravel the best brewing conditions for optimal extraction of the bioactive compounds and antioxidant capacity, while realising the best sensory properties. Infusions of eighty commercial teas (sold in bags or leaves) were obtained at different time-temperature ratios, studying bioactive compounds (caffeine and individual catechins), antioxidant capacity and sensory analysis. Brewing at 98 °C for 7 min was the best condition to obtain a high content of antioxidant polyphenols and pleasant sensory properties. Those teas sold in bags give rise to tea brews with almost double antioxidant capacity. In conclusion, it is very important to link sensory and chemical data to obtain optimal sensorial quality and the highest healthy properties in white tea infusions.

Relationship between composition and bioactivity of persimmon and kiwifruit.

Fruits are foods that contain plenty of vitamins, minerals and some bioactive phytochemicals like polyphenols. Thus, fruits may exert different functional properties on human health, some of which are directly related to their antioxidant capacity like cancer or atherosclerosis. Owing to globalization, consumers have a wide repertory of fruits throughout the year. Among them, tropical and subtropical fruits are steadily expanding, as well as the studies about them. In this sense, this timely review focused on the nutritional value and chemical composition of persimmon and kiwifruit, two tropical fruits with a protective role on different chronic diseases. Thus, this review focused mainly on the presence of bioactive compounds such as polyphenols, tannins, carotenoids, vitamin C and the different functional properties (i.e. antioxidant capacity, antithrombotic activity, decrease of plasmatic lipids, etc.) arising from the presence of such biologically active molecules. Finally, the effects of genotype and ripening stage on antioxidant capacity and the content of bioactive compounds in persimmon and kiwifruit are also discussed.

Characterization of commercial Spanish non-citrus juices: Antioxidant and physicochemical aspects.

The presence of many different antioxidant species makes fruit juices to be perceived by populations as a very healthy beverage easy to include in the daily diet. These antioxidant actions have been reported in a large number of papers, however the information correlating the antioxidant profile with the physicochemical characteristics derived from the industrial processing of fruit juices is limited. In a previous paper, our research group demonstrated that the antioxidant properties of citrus juices were underestimated when measuring by traditional methods and that our improved methodology, so-called GAR, is a better approach to analyze the global antioxidant response of juices. In this paper, we confirm that statement, establishing that the overall antioxidant capacity of non-citrus juices is 10-times higher with the GAR method (including an in vitro gastrointestinal digestion) that with the other methodologies. In some cases, such as pineapple juice, the antioxidant action was distributed between the soluble and non-soluble fractions almost at 50%. But, surprisingly, in some other (like tomato juice) the non-soluble fraction accounted for the higher antioxidant capacity. This fact definitively underlines the importance of the non-soluble fraction and shows the suitability of the GAR method to consider it. Physicochemical parameters, such as color, fluorescence, 5-hydroxymethylfurfural and furfural contents were correlated with antioxidant characteristics in some samples. Lastly, we unravel a mathematical model to classify non-citrus juices depending on their nature or storage conditions.

Sub-arcsecond imaging of the water emission in Arp 220.

AIMS: Extragalactic observations of water emission can provide valuable insights into the excitation of the interstellar medium. In particular they allow us to investigate the excitation mechanisms in obscured nuclei, i.e. whether an active galactic nucleus or a starburst dominate. METHODS: We use sub-arcsecond resolution observations to tackle the nature of the water emission in Arp 220. ALMA Band 5 science verification observations of the 183 GHz H2O 313-220 line, in conjunction with new ALMA Band 7 H2O 515-422 data at 325 GHz, and supplementary 22 GHz H2O 616 - 523 VLA observations, are used to better constrain the parameter space in the excitation modelling of the water lines. RESULTS: We detect 183 GHz H2O and 325 GHz water emission towards the two compact nuclei at the center of Arp 220, being brighter in Arp 220 West. The emission at these two frequencies is compared to previous single-dish data and does not show evidence of variability. The 183 and 325 GHz lines show similar spectra and kinematics, but the 22 GHz profile is significantly different in both nuclei due to a blend with an NH3 absorption line. CONCLUSIONS: Our findings suggest that the most likely scenario to cause the observed water emission in Arp 220 is a large number of independent masers originating from numerous star-forming regions.

The first CO+ image: I. Probing the HI/H2 layer around the ultracompact HII region Mon R2.

The CO+ reactive ion is thought to be a tracer of the boundary between a HII region and the hot molecular gas. In this study, we present the spatial distribution of the CO+ rotational emission toward the Mon R2 star-forming region. The CO+ emission presents a clumpy ring-like morphology, arising from a narrow dense layer around the HII region. We compare the CO+ distribution with other species present in photon-dominated regions (PDR), such as [CII] 158 µm, H2 S(3) rotational line at 9.3 µm, polycyclic aromatic hydrocarbons (PAHs) and HCO+. We find that the CO+ emission is spatially coincident with the PAHs and [CII] emission. This confirms that the CO+ emission arises from a narrow dense layer of the HI/H2 interface. We have determined the CO+ fractional abundance, relative to C+ toward three positions. The abundances range from 0.1 to 1.9 ×10-10 and are in good agreement with previous chemical model, which predicts that the production of CO+ in PDRs only occurs in dense regions with high UV fields. The CO+ linewidth is larger than those found in molecular gas tracers, and their central velocity are blue-shifted with respect to the molecular gas velocity. We interpret this as a hint that the CO+ is probing photo-evaporating clump surfaces.

Tryptophan transport through transport system T in the human erythrocyte, the Ehrlich cell and the rat intestine.

We studied the transport of tryptophan through transport system T in the human red cell, the Ehrlich ascites-tumour cell and in everted sacs of rat intestine. In red cells we confirmed earlier results on Na+-independence and aromatic amino acid specificity (Rosenberg, R., Young, J.D. and Ellory, J.C. (1980) Biochim. Biophys. Acta 598, 375-384). In addition we observed that N-methylation or N-acetylation did not reduce the affinity of the substrates for system T, hydroxylation could increase or decrease substrate affinity, and system T was insensitive to pH changes in the medium. These results characterized reactive differences between system T and other known amino acid transport systems. We also found that D-isomers were about 1/3 as effective as L-isomers to inhibit L-tryptophan uptake. D-Tryptophan competitively inhibited L-tryptophan uptake, but was not taken up by system T. L-Tryptophan produced trans-stimulation of the uptake (influx) and trans-inhibition of the release (efflux) of L-[3H]tryptophan; D-tryptophan produced trans-inhibition of the efflux but did not affect significantly the uptake. These results show that in red cells the transport properties of transport system T are asymmetric. Transport system T seems to be absent in the other two preparations studied, the Ehrlich ascites-tumour cell and the rat intestine.

Plasma membrane nadh dehydrogenase and Ca2+-dependent potassium transport in erythrocytes of several animal species.

Ca2+-dependent K+ transport and plasma membrane NADH dehydrogenase activities have been studied in several 'high-K+' (human, rabbit and guinea pig) and 'low-K+' (dog, cat and sheep) erythrocytes. All the species except sheep showed Ca2+-dependent K+ transport. NADH-ferricyanide reductase was detected in all the species and showed positive correlation with the flavin contents of the membranes. NADH-cytochrome c reductase was very low or absent in dog, sheep and guinea pig membranes. No correlation was found between NADH dehydrogenase and Ca2+-dependent K+ channel activities in the species studied. Nor were any of the above activities correlated with (Na+ + K+)-ATPase activity.

Activation of basolateral membrane K+ permeability by bradykinin in MDCK cells.

We study bradykinin-stimulated K+ efflux in Madin-Darby canine kidney (MDCK) cells using 86Rb as an isotopic tracer. Bradykinin brings about a rapid increase in the permeability of MDCK cells to K+, the effect is dose-dependent with a plateau at 10(-6) M. The effect seems to be mediated by Ca2+-activated K+ channels, localised at the basolateral aspect of the epithelium. Unlike alpha-receptors, which mediate a similar effect of adrenalin in these cells, bradykinin receptors seem to be present at both sides of the epithelium. Bradykinin increases the labelling of IP3, and bradykinin-stimulated K+ efflux persists even in cells which are bathed in Ca2+-free medium, suggesting that the effects seen in the present work are probably due to Ca2+ release from intracellular stores. Some extracellular Ca2+ also might be involved in the bradykinin effect, consistent with the kinin-increasing membrane permeability to Ca2+.

Protection against oxidative protein damage induced by metal-catalyzed reaction or alkylperoxyl radicals: comparative effects of melatonin and other antioxidants.

Melatonin is a well-known hydroxyl radical (*OH) scavenger that protects DNA and lipids from free radical attack. In this paper, we studied the ability of melatonin to prevent oxidative damage to bovine serum albumin (BSA) induced by two different paradigms: the metal-catalyzed oxidation (MCO) induced by Cu(2+)/H(2)O(2) and the alkoxyl and alkylperoxyl radicals formed by the azo initiator 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH, 40 mM). The protective effects of melatonin were compared with 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox), glutathione (GSH), ascorbate, 3,4',5-trihydroxy-trans-stilbene (resveratrol, 0.1 microM-4 mM) and mannitol (50 microM-100 mM). Melatonin efficiently prevented protein modification induced by both models, as assayed by polyacrylamide gel electrophoresis and carbonyl content. Both trolox and ascorbate had an obvious pro-oxidant effect in the Cu(2+)/H(2)O(2) model, whereas both prevented BSA damage induced by AAPH. In the MCO model, the efficacy of GSH in terms of protein protection was higher than melatonin at relatively high concentrations (250 microM-4 mM); however, at lower concentrations (50-250 microM), the efficacy of melatonin was superior to GSH. D-Mannitol (50 microM-100 mM) and resveratrol did not protect BSA from the site-specific damage induced by Cu(2+)/H(2)O(2). On the other hand, the relative protective efficiency in the AAPH model was melatonin approximately trolox>GSH>ascorbate.

Inhibition by nitrendipine of 86Rb+ fluxes in subconfluent MDCK cells.

Part of the natriuretic mechanism of dihydropyridine Ca2+ channel antagonists involves the inhibition of renal tubular sodium reabsorption. To identify the membrane ion transport system involved in this natriuretic action, we tested nitrendipine on unidirectional 86Rb+ fluxes in Madin-Darby canine kidney (MDCK) cells. To dissect between direct and indirect effects (via cytosolic Ca2+) of nitrendipine, the compound was re-examined on ion fluxes in human erythrocytes. In MDCK cells, external Ca2+ (3 mM), adrenalin (100 microM) and the Ca2+ ionophore A23187 (20 microM) strongly and transiently stimulated 86Rb+ efflux. All these stimulatory actions were fully inhibited by quinine (1 mM) suggesting that they reflect the opening of Ca(2+)-sensitive K+ channels. Nitrendipine was able to inhibit these Ca(2+)-sensitive K+ channels, bit this inhibitory action required concentrations of the compound (approximately 100 microM). Regarding 86Rb+ influx, the most significant result with nitrendipine was a partial inhibition of bumetanide-sensitive 86Rb+ influx. This effect represented a maximal flux inhibition of about 70% and required very low nitrendipine concentrations (IC50 approximately 1 nM). The Ca2+ ionophore A 23187 strongly stimulated bumetanide-sensitive 86Rb+ influx in MDCK cells. Conversely, a very important reduction (approximately 79%) of this influx component was found in Ca2+ depleted cells. In human red blood cells, Na+, K+, Cl- cotransport fluxes were resistant to nitrendipine, even at high concentrations of the compound (100-500 microM). Conversely, Ca(2+)-sensitive K+ channels were inhibited by nitrendipine with IC50 = 6 +/- 3 microM (mean +/- S.E.M., n = 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Relationships between melatonin, glutathione peroxidase, glutathione reductase, and catalase. Endogenous rhythms on cerebral cortex in Gallus domesticus.

In this report, we studied the endogenous rhythms of three antioxidant enzymes: glutathione peroxidase (E.C.1.11.1.9), glutathione reductase (E.C.1.6.4.2) and catalase (E.C.1.11.1.6) in cortex of chick brain and correlate them with physiological blood melatonin concentrations.