Photoswitching/back-switching assessment of biobased cellulose acetate/azobenzene handleable films under visible-light LED irradiation.

The light-induced processes performed by photofunctional polymer films are crucial aspects of developing integrated energy storage devices properly. Herein, we report the preparation, characterization, and study of the optical properties of a series of biobased cellulose acetate/azobenzene (CA/Az1) handleable films at different compositions. The photoswitching/back-switching behavior of the samples was investigated using varied LED irradiation sources. Additionally, poly(ethylene glycol) (PEG) was deposited onto cellulose acetate/azobenzene films to study the back-switching process's effect and nature in the fabricated films. Interestingly, the melting enthalpies of PEG before and after being irradiated with blue LED light were 2.5 mJ and 0.8 mJ, respectively. Conveniently, FTIR and UV-visible spectroscopy, thermogravimetry (TGA), contact angle, differential scanning calorimetry (DSC), polarized light microscopy (PLM), and atomic force microscopy (AFM) were used for the characterization of the sample films. Complementarily, theoretical electronic calculations provided a consistent approach to the energetic change in the dihedral angles and non-covalent interaction for the trans and cis isomer in the presence of cellulose acetate monomer. The results of this study revealed that CA/Az1 films are viable photoactive materials displaying handleability attributes with potential uses in harvesting, converting, and storing light energy.

Heterologous beta-nerve growth factor (ß-NGF) given at the LH surge enhances luteal function in dairy heifers.

Genetic selection for high yield milk production has led to a decline in dairy cattle's reproductive performance over the last 40 years. Low progesterone (P4) plasma content following ovulation is associated with suboptimal fertility in dairy cattle. Several pieces of evidence indicate that the protein beta-nerve growth factor (ß-NGF) that is present in the male seminal plasma exerts potent ovulatory and luteotrophic effects following systemic administration in camelids but also in other species. In this study, we determine whether systemic administration of purified llama ß-NGF given at the induced preovulatory luteinizing hormone (LH) peak improves corpus luteum (CL) function in dairy heifers subjected to an estradiol (E2) / P4 estrus-synchronization protocol. To achieve this, we first determined plasma E2 and LH hormone profiles to establish the timing of the estradiol benzoate (EB)-induced LH peak in estrus-synchronized heifers. Then, we tested whether the administration of ß-NGF given at the end of this peak affects the CL and its function by analyzing diameter, vascular area, and P4 output. Our results show that, with the estrus-synchronization protocol applied, plasma LH concentrations peaked (P < 0.01) 40-h and 16-h after removal of the bovine intravaginal device (DIB; containing 1.0 g of P4) plus cloprostenol injection and subsequent EB administration, respectively; after peaking, plasma LH concentrations remained stable for the next 8-h to then return to basal levels. Heifers synchronized with this protocol and receiving a dose of 1 mg of ß-NGF at the end of the LH peak (ie, 48-h after DIB removal) did not show significant differences in CL diameter, but these exhibited a greater CL vascular area (P = 0.01) than the observed in vehicle-injected heifers. Furthermore, plasma P4 concentration in ß-NGF-treated heifers was higher (P = 0.001) than those quantified in vehicle-injected heifers. These results support the use of ß-NGF in estrus-synchronization protocols to improve the early luteal function in dairy heifers.

Variation of the interphase heterochromatin in Artemia (Crustacea, Anostraca) of the Americas is related to changes in nuclear size and ionic composition of hipersaline habitats / Variação da heterocromatina interfásica em Artemia (Crustacea, Anostraca) das Américas está relacionada a mudanças no tamanho nuclear e composição iônica em habitats hipersalinos

Abstract The populations of Artemia (or brine shrimp) from the Americas exhibit a wide variation in the amount of interphase heterochromatin. There is interest in understanding how this variation affects different parameters, from the cellular to the organismal levels. This should help to clarify the ability of this organism to tolerate brine habitats regularly subject to strong abiotic changes. In this study, we assessed the amount of interphase heterochromatin per nucleus based on chromocenter number (N-CHR) and relative area of chromocenter (R-CHR) in two species of Artemia, A. franciscana (Kellog, 1906) (n=9 populations) and A. persimilis (Piccinelli and Prosdocimi, 1968) (n=3 populations), to investigate the effect on nuclear size (S-NUC). The relationship of the R-CHR parameter with the ionic composition (IC) of brine habitats was also analysed. Our results indicate a significant variation in the amount of heterochromatin both within and between species (ANOVA, p<0.001). The heterochromatin varied from 0.81 ± 1.17 to 12.58 ± 3.78 and from 0.19 ± 0.34% to 11.78 ± 3.71% across all populations, for N-CHR and R-CHR parameters, respectively. N-CHR showed less variation than R-CHR (variation index 15.5-fold vs. 62-fold). At least five populations showed a significant association (p<0.05) between R-CHR and S-NUC, either with negative (four populations, r= from -0.643 to -0.443), or positive (one population, r= 0.367) values.Within each species, there were no significant associations between both parameters (p>0.05). The R-CHR and IC parameters were associated significantly for the magnesium ion (r= 0.496, p<0.05) and also for the chloride, sodium and calcium ions (r = from -0.705 to -0.478, p<0.05). At species level, a significant association between both parameters was also found in A. franciscana populations, for the sulphate and calcium ions, in contrast to A. persimilis. These findings suggest that the amount of interphase heterochromatin modifies the nuclear size in Artemia. Our data also indicate that change in the amount of interphase heterochromatin is in line with the ionic composition of brines. This would be a species-specific phenomenon, whose occurrence may be involved in the ability of this organism to survive in these environments.

Resumo As populações de Artemia (ou camarão de salinas) das Américas apresentam uma grande variação na quantidade de heterocromatina interfásica. Há interesse em compreender como esta variação afeta diferentes parâmetros, desde o nível celular até os organismos. Isso deve ajudar a esclarecer a capacidade destes organismos tolerarem habitats extremos de água hipersalinas, que normalmente são submetidos a fortes mudanças abióticas. Neste estudo, avaliou-se a quantidade heterocromatina interfásica por núcleo através do número de cromocentros (N-CHR) e a área relativa de cromocentros (R-CHR) em duas espécies de Artemia, A. franciscana (Kellog, 1906) (n=9 populações) e A. persimilis (Piccinelli e Prosdocimi, 1968) (n=3 populações), para investigar o seu efeito no tamanho nuclear (S-NUC). Também foi analisada a relação de R-CHR com a composição iónica (CI) dos habitats hipersalinos. Nossos resultados indicam uma variação significativa na quantidade de heterocromatina dentro e entre espécies (ANOVA, p<0,001). Em todas as populações, a heterocromatina variou de 0,81 ± 1,17 para 12,58 ± 3,78 e de 0,19 ± 0,34% para 11,78 ± 3,71% para os parâmetros R-CHR e N-CHR, respectivamente. N-CHR apresentou menor variação do que R-CHR (amplitude de variação de 15,5 vezes vs. 62 vezes). Pelo menos cinco populações apresentaram uma associação significativa (p<0,05) entre R-CHR e S-NUC, seja com valores negativos (quatro populações, r = -0,643 a -0,443) ou positivo (uma população, r = 0,367). Os parâmetros R-CHR e CI foram associados significativamente para o íon de magnésio (r = 0,496, p<0,05) e também para os íons cloreto, sódio e cálcio (r = -0,705 a -0,478, p<0,05). Ao nível de espécie, foi também encontrada uma associação significativa entre esses dois parâmetros em populações de A. franciscana para os íons de sulfato e de cálcio, em contraste com A. persimilis. Estes achados sugerem que a quantidade heterocromatina interfásica modifica o tamanho nuclear em Artemia. Os nossos dados também indicam que a mudança na quantidade de heterocromatina interfásica está associada com a composição iónica das salinas. Este seria um fenómeno específico da espécie, cuja ocorrência pode estar envolvida na capacidade deste organismo sobreviver em tais ambientes.

Variation of the interphase heterochromatin in Artemia (Crustacea, Anostraca) of the Americas is related to changes in nuclear size and ionic composition of hipersaline habitats.

The populations of Artemia (or brine shrimp) from the Americas exhibit a wide variation in the amount of interphase heterochromatin. There is interest in understanding how this variation affects different parameters, from the cellular to the organismal levels. This should help to clarify the ability of this organism to tolerate brine habitats regularly subject to strong abiotic changes. In this study, we assessed the amount of interphase heterochromatin per nucleus based on chromocenter number (N-CHR) and relative area of chromocenter (R-CHR) in two species of Artemia, A. franciscana (Kellog, 1906) (n=9 populations) and A. persimilis (Piccinelli and Prosdocimi, 1968) (n=3 populations), to investigate the effect on nuclear size (S-NUC). The relationship of the R-CHR parameter with the ionic composition (IC) of brine habitats was also analysed. Our results indicate a significant variation in the amount of heterochromatin both within and between species (ANOVA, p<0.001). The heterochromatin varied from 0.81 ± 1.17 to 12.58 ± 3.78 and from 0.19 ± 0.34% to 11.78 ± 3.71% across all populations, for N-CHR and R-CHR parameters, respectively. N-CHR showed less variation than R-CHR (variation index 15.5-fold vs. 62-fold). At least five populations showed a significant association (p<0.05) between R-CHR and S-NUC, either with negative (four populations, r= from -0.643 to -0.443), or positive (one population, r= 0.367) values.Within each species, there were no significant associations between both parameters (p>0.05). The R-CHR and IC parameters were associated significantly for the magnesium ion (r= 0.496, p<0.05) and also for the chloride, sodium and calcium ions (r = from -0.705 to -0.478, p<0.05). At species level, a significant association between both parameters was also found in A. franciscana populations, for the sulphate and calcium ions, in contrast to A. persimilis. These findings suggest that the amount of interphase heterochromatin modifies the nuclear size in Artemia. Our data also indicate that change in the amount of interphase heterochromatin is in line with the ionic composition of brines. This would be a species-specific phenomenon, whose occurrence may be involved in the ability of this organism to survive in these environments.

Eco-immunology of fish invasions: the role of MHC variation.

The relationship between invaders and the pathogens encountered in their new environment can have a large effect on invasion success. Invaders can become free from their natural pathogens and reallocate costly immune resources to growth and reproduction, thereby increasing invasion success. Release from enemies and relaxation of selective pressures could render newly founded populations more variable at immune-related genes, such as the major histocompatibility complex (MHC), particularly when they have different origins. Using rainbow and brown trout, two of the world's most successful fish invaders, we tested the general hypothesis that invaders should display high intrapopulation immunogenetic diversity and interpopulation divergence, due to the interplay between genetic drift and successive waves of genetically divergent introductions. We analysed genetic diversity and signatures of selection at the MHC class II ß immune-related locus. In both species, MHC diversity (allelic richness and heterozygosity) for southern hemisphere populations was similar to values reported for populations at their native range. However, MHC functional diversity was limited, and population immunogenetic structuring weaker than that observed using neutral markers. Depleted MHC functional diversity could reflect a decrease in immune response, immune-related assortative mating or selection for resistance to newly encountered parasites. Given that the role of MHC diversity in the survival of these populations remains unclear, depleted functional diversity of invasive salmonids could compromise their long-term persistence. A better understanding of the eco-immunology of invaders may help in managing and preventing the impact of biological invasions, a major cause of loss of biodiversity worldwide.

Fuego quirúrgico: un incidente prevenible / Surgical fire: an avoidable incident

Introduction: surgical fire requires the presence of three components, known as the "fire triad": a fuel, an ignition source and an oxidizer. Clinical case: we report a patient who, during an ambulatory surgery, suffered a facial burn from a fire. The use of an electrosurgical unit and supplementary oxygen through nasal cannula were important factors in this case. We describe how and why fire start, which are the high-risk surgeries and the strategies to reduce the risk of fire in surgical patients.

Introducción: el fuego quirúrgico requiere tres elementos para que se produzca, conocidos como "triada de fuego": un combustible, una fuente de ignición y un oxidante. Caso clínico: presentamos el caso de una paciente que sufrió una quemadura facial por fuego durante una cirugía ambulatoria, en la que fueron factores importantes el uso de una unidad electroquirúrgica y la administración de oxígeno a través de una cánula nasal. Describimos cómo y por qué se puede producir fuego, cuáles son las cirugías de alto riesgo y las estrategias para reducir el riesgo de fuego en pacientes quirúrgicos.

Potential heterogeneity in crustacean zooplankton assemblages in southern chilean saline lakes.

The Chilean saline lakes are distributed mainly in the Atacama desert in northern Chile and the southern Patagonian plains. The scarce studies are restricted mainly to northern Chilean saline lakes, and these revealed that the main component in these ecosystems are the halophylic copepod Boeckella poopoensis Marsh 1906, or the brine shrimp Artemia franciscana (Kellog, 1906), and both species do not coexist. The present study consisted of field observations in zooplankton assemblages in southern Chilean saline lakes (51-53 ºS). These first observations revealed three different patterns, one saline lake only with A. persimilis (Piccinelli and Prosdocimi, 1968), a second lake only with B. poopensis, and a third lake with A. persimilis, B. poopoensis and unidentified harpacticoid copepod. These results are different in comparison with the observations in the literature that described the non-coexistence between B. poopoensis with brine shrimps. Ecological and biogeographical topics were discussed.

Species-specific RFLP pattern in the Heat Shock Protein26 gene (Hsp26): a single-locus tool for species identification and experimental testing of habitat-induced isolation in the New World Artemia species.

The brine shrimp Artemia (Crustacea, Branchiopoda), a paradigmatic inhabitant of hypersaline lakes, has molecular features to survive under stressful conditions, such as the p26 heat shock protein. We report the RFLP fingerprinting pattern (four restriction enzymes) of a 217 bp fragment of exon2 of the Hsp26 gene in six Artemia franciscana and four Artemia persimilis populations, the most genetically divergent Artemia species co-occurring in latitudinal extremes of Chile. The species-specific RFLP pattern observed is a simple and cost-effective single-locus tool for species delimitation and experimental testing the habitat-induced isolation barrier between them.

Cytologic, hormonal, and ultrasonographic correlates of the menstrual cycle of the New World monkey Cebus apella.

Few reports on the reproductive physiology of Cebus apella have been published. In this study we characterized menstrual cycle events by means of vaginal cytology, ultrasonography (US), and hormonal measurements in serum during three consecutive cycles in 10 females, and assessed the probability that ovulation would occur in the same ovary in consecutive cycles in 18 females. The lengths and phases of the cycles were determined according to vaginal cytology. Taking the first day of endometrial bleeding as the first day of the cycle, the mean cycle length +/- SEM was 19.5+/-0.4 days, with follicular and luteal phases lasting 8.2+/-0.2 and 11.3+/-0.4 days, respectively. The follicular phase included menstruation and the periovulatory period, which was characterized by the presence of a large number of superficial eosinophilic cells in the vaginal smear. The myometrium, endometrium, and ovaries were clearly distinguished on US examination. During each menstrual cycle a single follicle was recruited at random from either ovary. The follicle grew from 3 mm to a maximum diameter of 8-9 mm over the course of 8 days, in association with increasing estradiol (E(2)) serum levels (from 489+/-41 to 1600+/-92 pmol/L). At ovulation, the mean diameter of the dominant follicle usually decreased by >20%, 1 day after the maximum E(2) level was reached. Ovulation was associated with an abrupt fall in E(2), a decreased number of eosinophilic cells, the presence of leukocytes and intermediate cells in the vaginal smear, and a progressive increase in progesterone (P) levels that reached a maximum of 892+/-65 nmol/L on days 3-6 of the luteal phase. The menstrual cycle of Cebus apella differs in several temporal and quantitative aspects from that in humans and Old World primates, but it exhibits the same correlations between ovarian endocrine and morphologic parameters.

Eficacia de la tretinoína tópica en fotoenvejecimiento cutáneo: estudio doble ciego randomizado / Usefullness of topic tretinoine in skin photoaging: double bind study

Se realizó un estudio prospectivo, doble ciego para evaluar la eficacia de ácido retinoico en piel fotoenvejecida de brazos durante un período de doce meses 19 pacientes. Hubo una mejoría estadísticamente significativa del brazo tratado con el principio activo sobre el tratado con vehículo. Los efectos adversos se limitaron a una dermatitis irritativa leve del brazo tratado. Se confirma la utilidad y seguridad del uso de tretinoína tópica en el tratamiento del fotoenvejecimiento

International study on Artemia. LXII. Genomic relationships between Artemia franciscana and A. persimilis, inferred from chromocentre numbers.

Chromocentres, i.e. heavily stainable heterochromatic areas with highly repetitive DNA (a 130-bp repeat in the order of 6 x 105 copies per haploid genome) observed in the resting nucleus, are a reliable taxonomic trait and a good marker for speciation in Artemia. This chromosome marker was evaluated in populations of two New World sibling species: A. franciscana, from North, Central and South America, and A. persimilis from Argentina. Artemia persimilis showed the characteristically low average chromocentre numbers (<3) of the ancestral Mediterranean species, whilst higher numbers (>5) were seen in A. franciscana. The increase in chromocentre numbers from A. persimilis to A. franciscana occurred in a rather steady, continuous geographical pattern with an overlapping zone between both species. A north-south steady latitudinal decline of chomocentres was observed towards the equator in A. franciscana populations from the northern hemisphere, whilst the trait increased from this point towards southern latitudes with a population in Chilean Patagonia (below 52 degrees S) exhibiting the highest chromocentre frequency. Since chromocentres are positively correlated with repetitive DNA content, differentiation between the species through the amplification of heterochromatin or an increased DNA content in A. franciscana (although this species has a lower diploid chromosome number), might nevertheless reflect chromosomal reorganizations between the species. Chromocentres, together with other traits, reveal a probable hybrid zone between the two species in Chilean Patagonia.

Sperm migration through the female genital tract of the New World monkey Cebus apella.

This study was designed to characterize sperm migration in the female genital tract of Cebus apella. Forty-eight cycles of eighteen females mated during the periovulatory period were studied. Eggs were searched for and spermatozoa were counted in segmental flushings of the genital tract performed in situ 1-7 h, 19-31 h, or 45-56 h after coitus. Of 14 eggs recovered, 8 were fertilized, thus assuring a reasonable normality of prefertilization phenomena in both males and females. A downward gradient of several orders of magnitude in sperm numbers was recognized from cervix to ampulla, particularly over the first interval. The population in the cervix and uterus decreased progressively between the first and last interval. Spermatozoa were recovered from the ampulla as early as 1 h after mating. Different trends were observed in the isthmus and ampulla. From the first to the last interval, sperm numbers decreased in the ampulla, but not in the isthmus. The number of spermatozoa recovered from the ampulla of the ovulatory side 1-31 h postcoitum was higher in postovulatory than in preovulatory monkeys, while in the nonovulatory side, recovery was similar in the two conditions. This findings suggests that the passage of spermatozoa up to the site of fertilization is under local control and is synchronized with ovulation. The pattern of sperm migration that emerges from these data bears similarities to the pattern in nonprimate species as well as distinctive features. A unique feature in common with the pattern in human is the early establishment of a fairly abundant and persistent sperm population in the ampulla.

Psoriasis y ciclosporina: un intento de terapia tópica / Psoriasis and cyclosporine: an intent of topic therapy

In eight patients with chronic and stable psoriasis, the usefulness of topical cyclosporine solution using 50 percent dimethylsulfoxide as a vehicle was assessed in a randomly chosen plate and compared with a similar solution without cyclosporine in a contralateral plate. After six months of treatment, the plates involuted in two patients and in the rest there was a 1 to 3 points reduction in the local psoriasis area severity istry were detected. It is concluded that topical cyclosporine is effective in the treatment of psoriasis, but only after a prolonged application period