897 resultados para Screening and identification of vibrios


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Division of Fisheries, Illinois Department of Natural Resources Grant/Contract No: Federal Aid Project F-123 R-15

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Crystallization is employed in different industrial processes. The method and operation can differ depending on the nature of the substances involved. The aim of this study is to examine the effect of various operating conditions on the crystal properties in a chemical engineering design window with a focus on ultrasound assisted cooling crystallization. Batch to batch variations, minimal manufacturing steps and faster production times are factors which continuous crystallization seeks to resolve. Continuous processes scale-up is considered straightforward compared to batch processes owing to increase of processing time in the specific reactor. In cooling crystallization process, ultrasound can be used to control the crystal properties. Different model compounds were used to define the suitable process parameters for the modular crystallizer using equal operating conditions in each module. A final temperature of 20oC was employed in all experiments while the operating conditions differed. The studied process parameters and configuration of the crystallizer were manipulated to achieve a continuous operation without crystal clogging along the crystallization path. The results from the continuous experiment were compared with the batch crystallization results and analysed using the Malvern Morphologi G3 instrument to determine the crystal morphology and CSD. The modular crystallizer was operated successfully with three different residence times. At optimal process conditions, a longer residence time gives smaller crystals and narrower CSD. Based on the findings, at a constant initial solution concentration, the residence time had clear influence on crystal properties. The equal supersaturation criterion in each module offered better results compared to other cooling profiles. The combination of continuous crystallization and ultrasound has large potential to overcome clogging, obtain reproducible and narrow CSD, specific crystal morphologies and uniform particle sizes, and exclusion of milling stages in comparison to batch processes.

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Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 μg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 μg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 μg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.

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Introduction: Hospital malnutrition risk has prevalence values of 20%-50%, and it is a major health problem in the health institutions worldwide. Objective: To assess the accomplishment of nutritional screening and the prevalence of hospital malnutrition risk in a University Hospital. Materials and methods: A retrospective analysis was carried out with nutritional screening, using primary data from six clinical areas obtained in the period between July 2012 and December 2013. According to previous results in Mexican health institutions and considering a mean malnutrition risk prevalence of 50%, it was calculated that a sample size of 3200 subjects was required for the assessment of valid risk values. Patients with values ≥3 on the Nutritional Risk Screening (NRS, 2002) were classiied as carriers of nutritional risk. Results: A total of 5611 patients (38% of all patients admitted) were studied. The rate of screening declined from 55% in 2012 to 31% in 2013. During the whole period, 3034 patients were classiied with risk of malnutrition (54% prevalence). Conclusions: The prevalence of hospital malnutrition risk was high. The accomplishment of the nutritional screening was deicient, and declined between 2012 and 2013. The lack of nutritional screening does not meet the vital care requirements of hospitalized patients and prevents the timely treatment of those at malnutrition risk.

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Purpose: To investigate the phytochemistry and cytotoxic activity of stem bark extracts from Genus dolichocarpa and Duguetia chrysocarpa - two species of the Annonaceae family. Methods: The crude ethanol bark extracts (EtOH) of the plants were obtained by maceration. The crude extracts were suspended in a mixture of methanol (MeOH) and water (H2O) (proportion 3:7 v/v) and partitioned with hexane, chloroform (CHCl3) and ethyl acetate (AcOEt) in ascending order of polarity to obtain the respective fractions. The extracts were evaluated on thin layer chromatography (TLC) plates of silica gel to highlight the main groups of secondary metabolites. Cytotoxicity was tested against human tumor cell lines - OVCAR-8 (ovarian), SF-295 (brain) and HCT-116 (colon) - using 3- (4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results: The screening results demonstrated that all the extracts were positive for the presence of flavonoids and tannins. The presence of alkaloids also was detected in some extracts. The hexane extract of A. dolichocarpa showed the strongest cytotoxicity against HCT-116 with cell growth inhibition of 89.02 %. Conclusion: The findings demonstrate for the first time the cytotoxic activity of the extracts of A. dolichocarpa and D. chrysocarpa, thus providing some evidence that plants of the Annonaceae family are a source of active secondary metabolites with cytotoxic activity.

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Purpose: To investigate the lipid-lowering activity of two metabolites of galangin, namely, galangin-3-Oβ-D-glucuronic acid (GG-1) and galangin-7-O-β-D-glucuronic acid (GG-2). Methods: Female Sprague-Dawley rats were orally administered with galangin. The two metabolites of galangin were isolated from urine sample and purified using Sephadex LH-20 and semi-preparative high performance liquid chromatography (HPLC). The structures of the metabolites were identified by analyzing spectroscopic data. Hypolipidemic activity was evaluated in HepG2 cells. The down- or upregulation of lipogenic genes was detected using real-time quantitative polymerase chain reaction (qPCR). Results: Both metabolites of galangin showed hypolipidemic activity. These activities are closely associated with the down-regulation of lipogenic genes such as SREBP-1a, SREBP-1c, and SREBP-2 transcription factors, and the downstream genes such as FAS, ACC, and HMGR were revealed by realtime qPCR data. Conclusion: The results show that both metabolites possess better lipid-lowering activities than galangin. These hypolipidemic activities are closely associated with inhibiting key genes or proteins that regulated the biosynthesis of both cholesterol and triglycerides.

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Nowadays, one of the most important areas of interest in archeology is the characterization of the submersed cultural heritage. Mediterranean Sea is rich in archaeological findings due to storms, accidents and naval battles since prehistoric times. Chemical analysis of submerged materials is an extremely valuable source of information on the origin and precedence of the wrecks, and also the raw materials employed during the manufacturing of the objects found in these sites. Nevertheless, sometimes it is not possible to extract the archaeological material from the marine environment due to size of the sample, the legislation or preservation purposes. In these cases, the in-situ analysis turns into the only alternative for obtaining information. In spite of this demand, no analytical techniques are available for the in-situ chemical characterization of underwater materials. The versatility of laser-induced breakdown spectroscopy (LIBS) has been successfully tested in oceanography 1. Advantages such as rapid and in situ analysis with no sample preparation make LIBS a suitable alternative for field measurements. To further exploit the inherent advantages of the technology, a mobile fiber-based LIBS platform capable of performing remote measurements up to 50 meters range has been designed for the recognition and identification of artworks in underwater archaeological shipwrecks. The LIBS prototype featured both single-pulse (SP-LIBS) and multi-pulse excitation (MP-LIBS) 2. The use of multi-pulse excitation allowed an increased laser beam energy (up to 95 mJ) transmitted through the optical fiber. This excitation mode results in an improved performance of the equipment in terms of extended range of analysis (to a depth of 50 m) and a broader variety of samples to be analyzed (i.e., rocks, marble, ceramics and concrete). In the present work, the design and construction considerations of the instrument are reported and its performance is discussed on the basis of the spectral response, the remote irradiance achieved upon the range of analysis and its influence on plasma properties, as well as the effect of the laser pulse duration and purge gas to the LIBS signal. Also, to check the reliability and reproducibility of the instrument for field analysis several robustness tests were performed outside the lab. Finally, the capability of this instrument was successfully demonstrated in an underwater archaeological shipwreck (San Pedro de Alcántara, Malaga).

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The aims of this thesis were to determine the animal health status in organic dairy farms in Europe and to identify drivers for improving the current situation by means of a systemic approach. Prevalences of production diseases were determined in 192 herds in Germany, France, Spain, and Sweden (Paper I), and stakeholder consultations were performed to investigate potential drivers to improve animal health on the sector level (ibid.). Interactions between farm variables were assessed through impact analysis and evaluated to identify general system behaviour and classify components according to their outgoing and incoming impacts (Paper II-III). The mean values and variances of prevalences indicate that the common rules of organic dairy farming in Europe do not result in consistently low levels of production diseases. Stakeholders deemed it necessary to improve the current status and were generally in favour of establishing thresholds for the prevalence of production diseases in organic dairy herds as well as taking actions to improve farms below that threshold. In order to close the gap between the organic principle of health and the organic farming practice, there is the need to formulate a common objective of good animal health and to install instruments to ensure and prove that the aim is followed by all dairy farmers in Europe who sell their products under the organic label. Regular monitoring and evaluation of herd health performance based on reference values are considered preconditions for identifying farms not reaching the target and thus in need of improvement. Graph-based impact analysis was shown to be a suitable method for modeling and evaluating the manifold interactions between farm factors and for identifying the most influential components on the farm level taking into account direct and indirect impacts as well as impact strengths. Variables likely to affect the system as a whole, and the prevalence of production diseases in particular, varied largely between farms despite some general tendencies. This finding reflects the diversity of farm systems and underlines the importance of applying systemic approaches in health management. Reducing the complexity of farm systems and indicating farm-specific drivers, i.e. areas in a farm, where changes will have a large impact, the presented approach has the potential to complement and enrich current advisory practice and to support farmers’ decision-making in terms of animal health.