54 research outputs found

    Importance of bile composition for diagnosis of biliary obstructions

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    Determination of the cause of a biliary obstruction is often inconclusive from serum analysis alone without further clinical tests. To this end, serum markers as well as the composition of bile of 74 patients with biliary obstructions were determined to improve the diagnoses. The samples were collected from the patients during an endoscopic retrograde cholangiopancreatography (ERCP). The concentration of eight bile salts, specifically sodium cholate, sodium glycocholate, sodium taurocholate, sodium glycodeoxycholate, sodium chenodeoxycholate, sodium glycochenodeoxycholate, sodium taurodeoxycholate, and sodium taurochenodeoxycholate as well as bile cholesterol were determined by HPLC-MS. Serum alanine aminotransferase (ALT), aspartate transaminase (AST), and bilirubin were measured before the ERCP. The aim was to determine a diagnostic factor and gain insights into the influence of serum bilirubin as well as bile salts on diseases. Ratios of conjugated/unconjugated, primary/secondary, and taurine/glycine conjugated bile salts were determined to facilitate the comparison to literature data. Receiver operating characteristic (ROC) curves were determined, and the cut-off values were calculated by determining the point closest to (0,1). It was found that serum bilirubin was a good indicator of the type of biliary obstruction; it was able to differentiate between benign obstructions such as choledocholithiasis (at the concentration of >11 µmol/L) and malignant changes such as pancreatic neoplasms or cholangiocarcinoma (at the concentration of >59 µmol/L). In addition, it was shown that conjugated/unconjugated bile salts confirm the presence of an obstruction. With lower levels of conjugated/unconjugated bile salts the possibility for inflammation and, thus, neoplasms increase

    Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --

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    Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the background radiation level of other regions/countries

    Chemical preservation of tail feathers from Anchiornis huxleyi, a theropod dinosaur from the Tiaojishan Formation (Upper Jurassic, China)

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    A panel of geochemical techniques is used here to investigate the taphonomy of fossil feathers preserved in association with the skeleton of the Jurassic theropod Anchiornis huxleyi. Extant feathers were analysed in parallel to test whether the soft tissues morphologically preserved in the fossil also exhibit a high degree of chemical preservation. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) indicate that clays and iron oxide pseudomorphs occur in the surrounding sediment and also reveal the preservation of melanosome‐like microbodies in the fossil. Carbon gradient along a depth profile and co‐occurrence of carbon and sulphur are shown in the fossil by elastic backscattering (EBS) and particle‐induced x‐ray emission (PIXE), which are promising techniques for the elemental analysis of fossil soft tissues. The molecular composition of modern and fossil soft tissues was assessed from micro‐attenuated total reflectance fourier transform infrared spectroscopy (micro‐ATR FTIR), solid‐state 13C nuclear magnetic resonance (CP‐MAS 13C NMR) and pyrolysis gas chromatography mass spectrometry in the presence of TMAH (TMAH‐Py‐GC‐MS). Results indicate that the proteinaceous material that comprises the modern feathers is not present in the fossil feathers. The fossil feathers and the embedding sediment exhibit a highly aliphatic character. However, substantial differences exist between these samples, revealing that the organic matter of the fossil feathers is, at least partially, derived from original constituents of the feathers. Our results suggest that, despite the morphological preservation of Anchiornis feathers, original proteins, that is keratin, were probably not preserved in the 160‐myr‐old feathers

    CorE from Myxococcus xanthus Is a Copper-Dependent RNA Polymerase Sigma Factor

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    The dual toxicity/essentiality of copper forces cells to maintain a tightly regulated homeostasis for this metal in all living organisms, from bacteria to humans. Consequently, many genes have previously been reported to participate in copper detoxification in bacteria. Myxococcus xanthus, a prokaryote, encodes many proteins involved in copper homeostasis that are differentially regulated by this metal. A σ factor of the ECF (extracytoplasmic function) family, CorE, has been found to regulate the expression of the multicopper oxidase cuoB, the P1B-type ATPases copA and copB, and a gene encoding a protein with a heavy-metal-associated domain. Characterization of CorE has revealed that it requires copper to bind DNA in vitro. Genes regulated by CorE exhibit a characteristic expression profile, with a peak at 2 h after copper addition. Expression rapidly decreases thereafter to basal levels, although the metal is still present in the medium, indicating that the activity of CorE is modulated by a process of activation and inactivation. The use of monovalent and divalent metals to mimic Cu(I) and Cu(II), respectively, and of additives that favor the formation of the two redox states of this metal, has revealed that CorE is activated by Cu(II) and inactivated by Cu(I). The activation/inactivation properties of CorE reside in a Cys-rich domain located at the C terminus of the protein. Point mutations at these residues have allowed the identification of several Cys involved in the activation and inactivation of CorE. Based on these data, along with comparative genomic studies, a new group of ECF σ factors is proposed, which not only clearly differs mechanistically from the other σ factors so far characterized, but also from other metal regulators

    Comparative analyses imply that the enigmatic sigma factor 54 is a central controller of the bacterial exterior

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    Contains fulltext : 95738.pdf (publisher's version ) (Open Access)BACKGROUND: Sigma-54 is a central regulator in many pathogenic bacteria and has been linked to a multitude of cellular processes like nitrogen assimilation and important functional traits such as motility, virulence, and biofilm formation. Until now it has remained obscure whether these phenomena and the control by Sigma-54 share an underlying theme. RESULTS: We have uncovered the commonality by performing a range of comparative genome analyses. A) The presence of Sigma-54 and its associated activators was determined for all sequenced prokaryotes. We observed a phylum-dependent distribution that is suggestive of an evolutionary relationship between Sigma-54 and lipopolysaccharide and flagellar biosynthesis. B) All Sigma-54 activators were identified and annotated. The relation with phosphotransfer-mediated signaling (TCS and PTS) and the transport and assimilation of carboxylates and nitrogen containing metabolites was substantiated. C) The function annotations, that were represented within the genomic context of all genes encoding Sigma-54, its activators and its promoters, were analyzed for intra-phylum representation and inter-phylum conservation. Promoters were localized using a straightforward scoring strategy that was formulated to identify similar motifs. We found clear highly-represented and conserved genetic associations with genes that concern the transport and biosynthesis of the metabolic intermediates of exopolysaccharides, flagella, lipids, lipopolysaccharides, lipoproteins and peptidoglycan. CONCLUSION: Our analyses directly implicate Sigma-54 as a central player in the control over the processes that involve the physical interaction of an organism with its environment like in the colonization of a host (virulence) or the formation of biofilm

    Hydroliza materiałów keratynowych pochodzących z przemysłu drobiarskiego

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    In 2011, the European Union produced about 45 million tons of meat and in this time Poland occupied the fourth place in Europe in the production of poultry and pork meat and seventh in production of beef. The consumption of poultry meat grows year by year, which results in an increase of its production. Feathers consist in 90% of keratin and they make up 5-7% of the total weight of adult chickens what causes that feathers waste is the main source of keratin. Feathers are discarded in the process of the converting of poultry as a waste product and contribute to environmental pollution. The development of the poultry industry in the world has led to the generation of more than 4 million tons per year of waste feathers. Average farm size in Poland produces about 7 tons of chicken feathers a day. Nationally, during each year 77,000 tons of waste is produced. Keratin has a high immunity to physical and chemical factors and it is the reason of searching for new methods of keratin waste conversion. It would help to avoid a problem with storage of feather wastes. Application of alkaline hydrolysis is one of the ways of feathers utilizations. During this hydrolysis the keratin swells and is subject to degradation. The increase in solubility of keratin in bases is caused by peptide and disulfide bond cleavage and it leads to increase of keratin plasticity and decrease of its strength. The aim of this study was to determine the effect of process parameters on the degree of degradation of keratin and optimize the process to achieve its maximum value.W 2011 roku w Unii Europejskiej wyprodukowano około 45 mln ton mięsa. W tym czasie Polska zajmowała czwarte miejsce pod względem produkcji mięsa drobiowego oraz wieprzowego, była również siódmym producentem wołowiny. Spożycie mięsa drobiowego wzrasta z roku na rok, co skutkuje zwiększeniem jego produkcji. Pióra zbudowane są w 90% z keratyny i stanowią 5-7% całkowitej masy dorosłych kurczaków, wskutek czego są głównym źródłem odpadów keratynowych. W trakcie procesu przetwórstwa drobiu pióra są odrzucane, a jako produkt odpadowy przyczyniają się do zanieczyszczenia środowiska. Rozwój przemysłu drobiarskiego na świecie doprowadził do generowania ponad 4 milionów ton odpadowych piór rocznie. Średniej wielkości ferma w Polsce generuje około 7 ton pierza kurzego w ciągu doby, a w skali kraju rocznie wytwarzane jest 77 000 ton tego odpadu. Keratyna posiada wysoką odporność na czynniki fizyczne oraz chemiczne, co jest powodem poszukiwania nowych metod przetwarzania odpadów keratynowych. Pomoże to uniknąć problemów ze składowaniem odpadowego pierza. Zastosowanie hydrolizy zasadowej jest jednym ze sposobów utylizacji piór. Podczas tej hydrolizy keratyna pęcznieje i ulega degradacji. Rozerwanie wiązań peptydowych i disiarczkowych powoduje wzrost rozpuszczalności keratyn w zasadach oraz prowadzi do zwiększenia plastyczności keratyny i spadku jej wytrzymałości. Celem badań było określenie wpływu parametrów procesu na stopień degradacji keratyny oraz optymalizacja procesu w celu uzyskania jego maksymalnej wartości

    Analysis of the Process of Coal Micronization Conducted in Order to Obtain Coal-Water Liquids

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    Coal is the most important energy source, but its application in traditional way causes pollution. Preparation of coal-water liquids consists of: initial crushing of coal, wet milling in mixer mill and homogenization. To obtain coal-water liquids there were used three kinds of materials: coal of medium assortment with a low content of ash (6-25 mm), fine coal (0-20 mm) and coal sludge. The parameters of the grinding process which results in coal-water suspensions characterized by the most advantageous functional properties (high stability, low density and viscosity and the smallest equivalent diameter of particles of coal in a slurry) have been chosen and the influence of additives on the listed properties of the suspensions was determined. For suspensions consisted of water and coal independent parameters were vibration frequency 30 1/s, one ball with diameter of 15 mm and amount of water: 70 wt%. Substances which were applied to improve the properties of coal-water suspensions were: Triton X-405, sodium carboxymethyl cellulose and poly(acrylic acid), partial sodium salt-graft-poly(ethylene oxide). The best stability, low viscosity and the lowest density of the suspensions were characterized by coal, water and 0.1 wt% of carboxymethyl cellulose as a result of the 30 min milling

    Photorefractive Grating in Multiple Quantum Well Planar Waveguide

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    A photorefractive grating in a slab waveguide based on a semi-insulating AlGaAs/GaAs multiple quantum well structure with an electric field applied along the quantum well planes as an optically controlled, frequency selective mode coupling element with memory is analysed

    The bile salt content of human bile impacts on simulated intestinal proteolysis of β-lactoglobulin

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    The gastrointestinal hydrolysis of food proteins has been portrayed in scientific literature to predominantly depend on the activity and specificity of proteolytic enzymes. Human bile has not been considered to facilitate proteolysis in the small intestine, but rather to assist in intestinal lipolysis. However, human bile can potentially influence proteins that are largely resistant to gastric digestion, and which are mainly hydrolysed after they have been transferred to the small intestine. We used purified and food-grade bovine milk β-lactoglobulin (βLg) to assess the impact of bile salts (BS) on the in vitro gastrointestinal digestion of this protein. Quantitative analysis showed that the proteolysis rate increased significantly with increasing BS concentration. The effect was consistent regardless of whether individual BS or real human bile samples, varying in BS concentrations, were used. The total BS content of bile was more important than its BS composition in facilitating the proteolysis of βlg. We also show that the impact of human bile observed during the digestion of purified βLg and βLg-rich whey protein isolate can be closely replicated by the use of individual BS mixed with phosphatidylcholine. This could validate simple BS/phosphatidylcholine mixtures as human-relevant substitutes of difficult-to-obtain human bile for in vitro proteolysis studies
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