396 research outputs found

    Characterization of plant-derived lactococci on the basis of their volatile compounds profile when grown in milk

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    peer-reviewedA total of twelve strains of lactococci were isolated from grass and vegetables (baby corn and fresh green peas). Ten of the isolates were classified as Lactococcus lactis subsp. lactis and two as Lactococcus lactis subsp. cremoris based on 16S rDNA sequencing. Most of the plant-derived strains were capable of metabolising a wide range of carbohydrates in that they fermented D-mannitol, amygdalin, potassium gluconate, l-arabinose, d-xylose, sucrose and gentibiose. None of the dairy control strains (i.e. L. lactis subsp. cremoris HP, L. lactis subsp. lactis IL1403 and Lactococcus lactis 303) were able to utilize any of these carbohydrates. The technological potential of the isolates as flavour-producing lactococci was evaluated by analysing their growth in milk and their ability to produce volatile compounds using solid phase micro-extraction of the headspace coupled to gas chromatography–mass spectrometry (SPME GC–MS). Principal component analysis (PCA) of the volatile compounds clearly separated the dairy strains from the plant derived strains, with higher levels of most flavour rich compounds. The flavour compounds produced by the plant isolates among others included; fatty acids such as 2- and 3-methylbutanoic acids, and hexanoic acid, several esters (e.g. butyl acetate and ethyl butanoate) and ketones (e.g. acetoin, diacetyl and 2-heptanone), all of which have been associated with desirable and more mature flavours in cheese. As such the production of a larger number of volatile compounds is a distinguishing feature of plant-derived lactococci and might be a desirable trait for the production of dairy products with enhanced flavour and/or aroma

    Internal flow measurements of the SSME fuel preburner injector element using real time neutron radiography

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77098/1/AIAA-1990-2293-658.pd

    In Vitro Assay for Phototoxic Chemicals

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    The photosensitizing potential of chemicals known to produce photosensitivity in humans was compared to chemicals not considered to be photosensitizers in an in vitro assay. The assay involved exposure of human lymphoid cells to UVA (320–400 nm), and in some cases UVB (280-320 nm) radiation, in the presence of the chemicals and the assessment of phototoxicity as measured by the incorporation of 3[H]-thymidine into nuclear DNA. All known photosensitizers tested were found to be phototoxic, while the nonphotosensitizing agents, with the exception of retinoic acid, were not phototoxic. Peripheral blood mononuclear cells were compared to a T lymphoblastoid cell line as target cells; the latter were superior in terms of convenience, cost and reproducibility of results. This test system has potential as a predictive assay for detecting additional phototoxic chemicals

    Cardiomyopathy in Offspring of Pregestational Diabetic Mouse Pregnancy

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    Purpose. To investigate cardiomyopathy in offspring in a mouse model of pregestational type 1 diabetic pregnancy. Methods. Pregestational diabetes was induced with STZ administration in female C57BL6/J mice that were subsequently mated with healthy C57BL6/J males. Offspring were sacrificed at embryonic day 18.5 and 6-week adolescent and 12-week adult stages. The size and number of cardiomyocyte nuclei and also the extent of collagen deposition within the hearts of diabetic and control offspring were assessed following cardiac tissue staining with either haematoxylin and eosin or Picrosirius red and subsequently quantified using automated digital image analysis. Results. Offspring from diabetic mice at embryonic day 18.5 had a significantly higher number of cardiomyocyte nuclei present compared to controls. These nuclei were also significantly smaller than controls. Collagen deposition was shown to be significantly increased in the hearts of diabetic offspring at the same age. No significant differences were found between the groups at 6 and 12 weeks. Conclusions. Our results from offspring of type 1 diabetic mice show increased myocardial collagen deposition in late gestation and have increased myocardial nuclear counts (hyperplasia) as opposed to increased myocardial nuclear size (hypertrophy) in late gestation. These changes normalize postpartum after removal from the maternal intrauterine environment

    Effects of cropping systems upon the three-dimensional architecture of soil systems are modulated by texture

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    Soil delivers fundamental ecosystem functions via interactions between physical and biological processes mediated by soil structure. The structure of soil is also dynamic and modified by natural factors and management intervention. The aim of this study was to investigate the effects of different cropping systems on soil structure at contrasting spatial scales. Three systems were studied in replicated plot field experiments involving varying degrees of plant-derived inputs to the soil, viz. perennial (grassland), annual (arable), and no-plant control (bare fallow), associated with two contrasting soil textures (clayey and sandy). We hypothesized the presence of plants results in a greater range (diversity) of pore sizes and that perennial cropping systems invoke greater structural heterogeneity. Accordingly, the nature of the pore systems was visualised and quantified in 3D by X-ray Computed Tomography at the mm and μm scale. Plants did not affect the porosity of clay soil at the mm scale, but at the μm scale, annual and perennial plant cover resulted in significantly increased porosity, a wider range of pore sizes and greater connectivity compared to bare fallow soil. However, the opposite occurred in the sandy soil, where plants decreased the porosity and pore connectivity at the mm scale but had no significant structural effect at the μm scale. These data reveal profound effects of different agricultural management systems upon soil structural modification, which are strongly modulated by the extent of plant presence and also contingent on the inherent texture of the soil

    Study protocol for evaluating the implementation and effectiveness of an emergency department longitudinal patient monitoring system using a mixed-methods approach

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    Background: Early detection of patient deterioration is a key element of patient safety as it allows timely clinical intervention and potential rescue, thus reducing the risks of serious patient safety incidents. Longitudinal patient monitoring systems have been widely recommended for use to detect clinical deterioration. However, there is conflicting evidence on whether they improve patient outcomes. This may in part be related to variation in the rigour with which they are implemented and evaluated. This study aims to evaluate the implementation and effectiveness of a longitudinal patient monitoring system designed for adult patients in the unique environment of the Emergency Department (ED). Methods: A novel participatory action research (PAR) approach is taken where socio-technical systems (STS) theory and analysis informs the implementation through the improvement methodology of ‘Plan Do Study Act’ (PDSA) cycles. We hypothesise that conducting an STS analysis of the ED before beginning the PDSA cycles will provide for a much richer understanding of the current situation and possible challenges to implementing the ED-specific longitudinal patient monitoring system. This methodology will enable both a process and an outcome evaluation of implementing the ED-specific longitudinal patient monitoring system. Process evaluations can help distinguish between interventions that have inherent faults and those that are badly executed. Discussion: Over 1.2 million patients attend EDs annually in Ireland; the successful implementation of an ED-specific longitudinal patient monitoring system has the potential to affect the care of a significant number of such patients. To the best of our knowledge, this is the first study combining PAR, STS and multiple PDSA cycles to evaluate the implementation of an ED-specific longitudinal patient monitoring system and to determine (through process and outcome evaluation) whether this system can significantly improve patient outcomes by early detection and appropriate intervention for patients at risk of clinical deterioration

    A Root-Cause Analysis of Mortality Following Major Pancreatectomy

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    Abstract Introduction Although mortality rates from pancreatectomy have decreased worldwide, death remains an infrequent but profound event at an individual practice level. Root-cause analysis is a retrospective method commonly employed to understand adverse events. We evaluate whether emerging mortality risk assessment tools sufficiently predict and account for actual clinical events that are often identified by root-cause analysis. Methods We assembled a Pancreatic Surgery Mortality Study Group comprised of 36 pancreatic surgeons from 15 institutions in 4 countries. Mortalities after pancreatectomy (30 and 90 days) were accrued from 2000 to 2010. For root-cause analysis, each surgeon "deconstructed" the clinical events preceding a death to determine cause. We next tested whether mortality risk assessment tools (ASA, POSSUM, Charlson, SOAR, and NSQIP) could predict those patients who would die (n=218) and compared their prognostic accuracy against a cohort of resections in which no patient died (n=1,177). Results Two hundred eighteen deaths (184 Whipple's resection, 18 distal pancreatectomies, and 16 total pancreatectomies) were identified from 11,559 pancreatectomies performed by surgeons whose experience averaged 14.5 years. Overall 30-and 90-day mortalities were 0.96% and 1.89%, respectively. Individual surgeon rates ranged from 0% to 4.7%. Only 5 patients died intraoperatively, while the other 213 succumbed at a median of 29 days. Mean patient age was 70 years old (38% were >75 years old). Malignancy was the indication in 90% of cases, mostly pancreatic cancer (57%). Median operative time was 365 min and estimated blood loss was 700 cc (range, 100-16,000 cc). Vascular repair or multivisceral resections were required for 19.7% and 15.1%, respectively. Seventy-seven percent had a variety of major complications before death. Eighty-seven percent required intensive care unit care, 55% were transfused, and 35% were reoperated upon. Fifty percent died during the index admission, while another 11% died after a readmission. Almost half (n=107) expired between 31 and 90 days. Only 11% had autopsies. Operation-related complications contributed to 40% of deaths, with pancreatic fistula being the most evident (14%). Technical errors (21%) and poor patient selection (15%) were cited by surgeons. Of deaths, 5.5% had associated cancer progression-all occurring between 31 and 90 days. Even after root-cause scrutiny, the ultimate cause of death could not be determined for a quarter of the patients-most often between 31 and 90 days. While assorted risk models predicted mortality with variable discrimination from nonmortalities, they consistently underestimated the actual mortality events we report. Conclusion Root-cause analysis suggests that risk prediction should include, if not emphasize, operative factors related to pancreatectomy. While risk models can distinguish between mortalities and nonmortalities in a collective fashion, they vastly miscalculate the actual chance of death on an individual basis. This study reveals the contributions of both comorbidities and aggressive surgical decisions to mortality
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