133 research outputs found
Trematode Centrocestus formosanus Infection and Distribution in Ornamental Fishes in Mexico
Análisis de la distribución del Trematodo Centrocestus formosanus en peces de ornatoThe aim of this study was to determine the ornamental fish species affected by the metacercariae of the digenean trematode Centrocestus formosanus and its distribution in 48 fish farms in Morelos, central Mexico. The parasite was found to form various numbers of branchial cysts in 11 of the 25 species analyzed. Goldfish Carassius auratus was the most commonly affected species; 20 of 30 farms were positive for this parasite, the fish showing severe clinical signs and having a high mortality rate. For the first time in the region, koi (a variant of common carp Cyprinus carpio), zebrafish Danio rerio, suckermouth catfish Hypostomus plecostomus and blue gourami Trichogaster trichopterus (also known as the threespot gourami) were positive; meanwhile, Mexican tetra Astyanax mexicanus, which had previously been reported positive in other studies in this region, was found to be negative. The parasite was observed in fish from 27 of the 48 farms studied. Ten of 15 municipalities had farms that were positive for the parasite. These results suggest that the distribution of C. formosanus is closely related to the use of water that had been contaminated with the parasite and to the presence of a snail, the red-rimmed melania Melanoides tuberculata.Asociación de Productores de Peces de Ornato of Morelos State
Alternative and simple normal-phase HPLC enantioseparation of a chiral amino acid-type spin label derivative
In this work an alternative chromatographic process was developed for fractionating the (+)-(3R,4R) and ( - )-(3S,4S) enantiomers of the chiral trans β-amino acid trans-2,2,5,5-tetramethylpyrrolidine-3-amino-4-carboxylic acid (POAC), which was protected at its amine group for further coupling to a peptide, polymer or other macromolecule. The HPLC enantioseparation was achieved using a chiral cellulose-based normal stationary phase and isocratic elution. The n-hexane:isopropanol system, always with greater amount of the former component, was used as mobile phase as revealed by improved fractionation property of both components, demonstrated by the separation factor and resolution index values. These parameters presented values of 3.7 and 18.4 and of 2.0 and 6.7 when in 90:10 (v/v) and 80:20 (v/v) n-hexane:isopropanol solutions, respectively. These findings indicate that the one-step chromatographic purification strategy using normal-phase is feasible, thus opening the perspective of a fast large-scale production this paramagnetic spin probe.Neste trabalho desenvolveu-se um processo alternativo para separação cromatográfica dos enantiômeros (+)-(3R,4R) e ( - )-(3S,4S) do β-aminoácido quiral trans-2,2,5,5-tetrametilpirrolidina-3-amino-4-carboxílico (POAC), que estava protegido no grupo amínico para posterior ligação a um peptídeo, polímero ou outra macromolécula. A enantioseparação foi obtida por HPLC usando uma fase estacionária normal à base de celulose quiral e eluição isocrática. O sistema n-hexano:isopropanol, sempre com maior quantidade do primeiro solvente, foi usado como fase móvel, pois forneceu os melhores resultados na separação dos dois componentes, constatado pelos valores mais elevados de fator de separação e de índice de resolução cromatográfica. Estes parâmetros apresentaram valores de 3,7 e 18,4 e de 2,0 e 6,7 nas soluções com proporção 90:10 (v/v) e 80:20 (v/v) de n-hexano:isopropanol, respectivamente. Estes dados indicam que a estratégia de purificação cromatográfica em uma única etapa usando fase normal é viável, abrindo assim a perspectiva de uma produção rápida e em grande escala desta sonda paramagnética.18401845Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Application of Simulated Annealing and Hybrid Methods in the Solution of Inverse Heat and Mass Transfer Problems
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Efficient separation of carbon dioxide and methane in high-pressure and wet gas mixtures using Zr-MOF-808
The capture and separation of carbon dioxide (CO2) has been the focus of a plethora of research in order to mitigate its emissions and contribute to global development. Given that CO2 is commonly found in natural gas streams, there have been efforts to seek more efficient materials to separate gaseous mixtures such as CO2/CH4. However, there are only a few reports regarding adsorption processes within pressurized systems. In the offshore scenario, natural gas streams still exhibit high moisture content, necessitating a greater understanding of processes in moist systems. In this article, a metal-organic framework synthesis based on zirconium (MOF-808) was carried out through a conventional solvothermal method and autoclave for the adsorption of CO2 and CH4 under different temperatures (45–65 °C) and pressures up to 100 bar. Furthermore, the adsorption of humid CO2 was evaluated using thermal analyses. The MOF-808 synthesized in autoclave showed a high surface area (1502 m2/g), a high capacity for CO2 adsorption at 50 bar and 45 °C and had a low selectivity to capture CH4 molecules. It also exhibited a fine stability after five cycles of CO2 adsorption and desorption at 50 bar and 45 °C − as confirmed by structural post-adsorption analyses while maintaining its adsorption capacity and crystallinity. Furthermore, it can be observed that the adsorption capacity increased in a humid environment, and that the adsorbent remained stable after adsorption cycles in the presence of moisture. Finally, it was possible to confirm the occurrence of physisorption processes through nuclear magnetic resonance (NMR) analyses, thus validating the choice of mild temperatures for regeneration and contributing to the reduction of energy consumption in processing plants
Estudio de caso de sindrome neurologico asociado a astrocitoma
El astrocitoma es una neoplasia primaria del sistema nervioso central que se puede presentar en los animales; de las especies domésticas se ha observado con mayor frecuencia en los perros, de éstos, la edad y la raza son factores que influyen en su presentación, en estudios anteriores han descrito que el astrocitoma es una neoplasia que se presenta con mayor frecuencia en perros de características braquicefalicas, además que su malignidad depende de la localización y del carácter invasivo que presenta. Se presenta el estudio de caso de un paciente canino Labrador, macho de 6 años de edad, con un cuadro clínico neurológico de origen compresivo y obstructivo, derivado de una neoplasia intracraneala. Se documentó el caso a través del método clínico, basado en la historia clínica y la evolución del caso, imagenología e histopatología. Lo observado a través de las placas, correspondieron a una masa tumoral en la región ventral correspondiente al diencéfalo cuya localización se refiere adyacente a la estructura hipotalámica con efecto obstructivo y compresivo compatible con un astrocitoma; al estudio anatomopatológico se observo un tumor localizado adyacente al hipotálamo del cerebro; histológicamente el tumor se identifico como un astrocitoma gemistocítico
Influence of different beverages on the force degradation of intermaxillary elastics: an in vitro study
OBJECTIVE: The aim of this study was to evaluate in vitro the effects of frequently ingested beverages on force degradation of intermaxillary elastics. MATERIAL AND METHODS: One hundred and eighty 1/4-inch intermaxillary elastics (TP Orthodontics) were immersed into six different beverages: (1) Coca-Cola(®); (2) Beer; (3) Orange juice; (4) Red wine; (5) Coffee and (6) artificial saliva (control). The period of immersion was 15 min for the first and second cycles and 30 min for the third to fifth cycles. Tensile forces were read in a tensile testing machine before and after the five immersion cycles. One-way repeated measures ANOVA was used to identify significant differences. RESULTS: Force degradation was seen in all evaluated groups and at all observation periods (p<0.05). A greater degree of degradation was present at the initial periods, decreasing gradually over time. However, no statistically significant differences were seen among groups at the same periods, showing that different groups behaved similarly. CONCLUSION: The chemical nature of the evaluated beverages was not able to influence the degree of force degradation at all observation periods
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Epilepsy phenotype and its reproducibility after lateral fluid percussion‐induced traumatic brain injury in rats: Multicenter EpiBioS4Rx study project 1
ObjectiveThis study was undertaken to assess reproducibility of the epilepsy outcome and phenotype in a lateral fluid percussion model of posttraumatic epilepsy (PTE) across three study sites.MethodsA total of 525 adult male Sprague Dawley rats were randomized to lateral fluid percussion-induced brain injury (FPI) or sham operation. Of these, 264 were assigned to magnetic resonance imaging (MRI cohort, 43 sham, 221 traumatic brain injury [TBI]) and 261 to electrophysiological follow-up (EEG cohort, 41 sham, 220 TBI). A major effort was made to harmonize the rats, materials, equipment, procedures, and monitoring systems. On the 7th post-TBI month, rats were video-EEG monitored for epilepsy diagnosis.ResultsA total of 245 rats were video-EEG phenotyped for epilepsy on the 7th postinjury month (121 in MRI cohort, 124 in EEG cohort). In the whole cohort (n = 245), the prevalence of PTE in rats with TBI was 22%, being 27% in the MRI and 18% in the EEG cohort (p > .05). Prevalence of PTE did not differ between the three study sites (p > .05). The average seizure frequency was .317 ± .725 seizures/day at University of Eastern Finland (UEF; Finland), .085 ± .067 at Monash University (Monash; Australia), and .299 ± .266 at University of California, Los Angeles (UCLA; USA; p < .01 as compared to Monash). The average seizure duration did not differ between UEF (104 ± 48 s), Monash (90 ± 33 s), and UCLA (105 ± 473 s; p > .05). Of the 219 seizures, 53% occurred as part of a seizure cluster (≥3 seizures/24 h; p >.05 between the study sites). Of the 209 seizures, 56% occurred during lights-on period and 44% during lights-off period (p > .05 between the study sites).SignificanceThe PTE phenotype induced by lateral FPI is reproducible in a multicenter design. Our study supports the feasibility of performing preclinical multicenter trials in PTE to increase statistical power and experimental rigor to produce clinically translatable data to combat epileptogenesis after TBI
Length-weight relationships and condition factor of eight fish species inhabiting the Rocha Lagoon, Uruguay
Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: The ZIKAlliance consortium
Background: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. Methods: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmissio
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