55 research outputs found
Metagenomic Evaluation of Bacteria from Voles
Voles (Arvicolinae, Rodentia) are known carriers of zoonotic bacteria such as Bartonella spp. and Francisella tularensis. However, apart from F. tularensis, the bacterial microbiome of voles has not previously been determined in Finland and rarely elsewhere. Therefore, we studied liver samples from 61 voles using 16S ribosomal RNA gene PCR analysis, followed by Sanger sequencing. Twenty-three of these samples were also studied with tag-encoded pyrosequencing. The samples originated from 21 field voles (Microtus agrestis), 37 tundra voles (Microtus oeconomus), and 3 bank voles (Myodes glareolus). With the more conventional 16S rDNA PCR analysis, 90 (33%) of the recovered 269 sequence types could be identified to genus level, including Bartonella, Francisella, Mycoplasma, Anaplasma, and Acinetobacter in 31, 15, 9, 9, and 9 sequences, respectively. Seventy-five (28%) matched best with sequences of uncultured bacteria, of which 40/75 could be classified to the order Clostridiales and, more specifically, to families Lachnospiraceae and Ruminococcaceae. Pyrosequencing from 23 samples revealed comparable and similar results: clinically relevant bacterial families such as Mycoplasmataceae, Bartonellaceae, Anaplasmataceae, and Francisellaceae were recognized. These analyses revealed significant bacterial diversity in vole livers, consisting of distinct and constant sequence patterns reflecting bacteria found in the intestinal gut, but including some known zoonotic pathogens as well. The molecular bacterial sequence types determined with the two different techniques shared major similarities and verified remarkable congruency between the methods.Peer reviewe
Calculation and comparison of heat transfer coefficient & heat flux by varying the parameters for SCWR through CFD simulations
In the present study, CFD simulation was conducted for 2•2 rod bare bundle using water at supercritical pressures. Main objective of the simulation was to compare working of different turbulence models. K-epsilon, K-omega and Spalart-Allmaras turbulence models were chosen for our study. K-epsilon and K-omega turbulence models are two equation models and are widely used for industrial research. Whereas Spalart-Allmaras is one equation model which is least computationally expensive of all the models. All three turbulence models come under the Reynolds Average Navier Strokes model (RANS). CFD results were found to be sensitive with the appropriate turbulence model and this variation is documented through various plots
Nanofiltration and reverse osmosis as a platform for production of natural botanic extracts: the case study of carob by-products
Carob kibbles are a low-cost and renewable source of economically relevant phenolic compounds (high value catechin and its derivatives and gallic acid) and abundant in small sugars. This work aims at producing two distinct natural extracts from carob kibbles, one extract enriched in catechin and its derivatives for the nutraceuticals market and an extract enriched in sugars for the food industry. This valorisation strategy involves an integrated process based on membrane technology that fulfils the zero discharge principle and may be applied to other agro-industrial by-products. Different aqueous extraction schemes were considered (a one-step process and a two-steps approach). The aqueous extracts obtained were fractionated by diananofiltration and the fractions obtained were evaluated in terms of their content in target products. An integrated scheme for production of fractionated extracts is proposed based on the experimental work developed assuring, simultaneously, a minimal use of resources and emission of waste
Nanofiltration of hormone mimicking trace organic contaminants
The removal mechanisms of three hormone mimicking organic compounds by nanofiltration (NF)
membranes have been examined. Two NF membranes having different pore size were used in
laboratory-scale nanofiltration experiments with feed solutions spiked with a hormone mimicking
compound ¾ nonylphenol, tert-butyl phenol, or bisphenol A. Retention of the compounds was
determined at various solution chemistries, namely aqueous solution pH, ionic strength, and
presence of natural organic matter. The nanofiltration behavior of the selected hormone mimicking
compounds appears similar to that of natural hormones as reported in our previous work. While the
solution pH can dramatically influence the retention of hormone mimicking compounds by a loose
NF membrane, ionic strength does not affect the nanofiltration of such contaminants. However, in
the presence of natural organic matter in the feed solution, ionic strength appears to play a
significant role in solute-solute and solute-membrane interactions, resulting in increased retention
due to partitioning of the hormone mimicking compounds onto organic matter at a higher ionic
strength
Transcranial light alters melanopsin and monoamine production in mouse (Mus musculus) brain
Abstract
Background: The mammalian circadian system sets a rhythm for the appropriate occurrence of physiological and behavioral phenomena during a 24-h period. Since the duration of the circadian system is usually less or more than 24 h, it must be entrained regularly and light is the governing stimulus of the rhythm. The target for light stimulus is the master circadian clock, which is located in the suprachiasmatic nucleus in the hypothalamus. One of the key molecules transmitting light information and entraining the clock is melanopsin (OPN4), a G protein-coupled molecule that is found most abundantly in the retina and brain. Although light stimulus is usually mediated through the eyes, light has an ability to penetrate the skull. Here, we present the effect of transcranial light illumination on OPN4 and serotonin expression in the mouse brain.
Methods: Male mice were randomly assigned to a control group, morning-light group and evening-light group, and animals were illuminated transcranially five times a week for 8 min for a total of 4 weeks. The concentrations of OPN4 and monoamines were analyzed with Western blot and high-performance liquid chromatography (HPLC) techniques, respectively.
Results: Our results show that transcranial light illumination increases the amount of OPN4 in the hypothalamus and cerebellum. Additionally, the production of serotonin in the cortex was shown to decrease in the morning-light group.
Conclusions: With this study, we provide novel information on the effects of light administration through the skull on transmitters regulating circadian rhythmicity by showing that transcranial light affects molecules involved in circadian rhythmicity
Selective recovery of phenolic compounds and carbohydrates from carob kibbles using water-based extraction
Carob kibbles are an important renewable source of valuable compounds, such as fermentable sugars and phenolic compounds. However, the selective recovery of these compounds is not a trivial task. In this work, a strategy was developed to enable the recovery of both classes of compounds by means of awater-based extraction.One-step extraction recovered only approximately 20% of the phenolic compounds, corresponding to an extraction yield of 0.6 g Gallic acid equivalents (GAE)/100 g dry mass of carob kibbles. The obtained extract contained a significant amount of carbohydrates (110 g/L). The alternative two-step extraction developed enabled higher compound selectivity together with an increase in the yield of the phenolic compounds to about 70%, corresponding to 1.9 gGAE/100 g carob dry matter.The two-step extraction was easily scaled-up and is an effective method to obtain significantly sepa-rated carbohydrates and polyphenol-rich streams that can be further processed, e.g., in biorefineries orfood industries, respectively
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