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排序方式: 共有3111条查询结果,搜索用时 15 毫秒
91.
Søltoft M Bysted A Madsen KH Mark AB Bügel SG Nielsen J Knuthsen P 《Journal of the science of food and agriculture》2011,91(4):767-775
BACKGROUND: The demand for organic food products has increased during the last decades due to their probable health effects, among others. A higher content of secondary metabolites such as carotenoids in organic food products has been claimed, though not documented, to contribute to increased health effects of organic foods. The aim was to study the impact of organic and conventional agricultural systems on the content of carotenoids in carrots and human diets. In addition, a human cross‐over study was performed, measuring the plasma status of carotenoids in humans consuming diets made from crops from these agricultural systems. RESULTS: The content of carotenoids in carrot roots and human diets was not significantly affected by the agricultural production system or year, despite differences in fertilisation strategy and levels. The plasma status of carotenoids increased significantly after consumption of the organic and conventional diets, but no systematic differences between the agricultural production systems were observed. CONCLUSION: The expected higher content of presumed health‐promoting carotenoids in organic food products was not documented in this study. Copyright © 2011 Society of Chemical Industry 相似文献
92.
Eicosapentaenoic and docosahexaenoic acid affect mitochondrial and peroxisomal fatty acid oxidation in relation to substrate preference 总被引:1,自引:0,他引:1
Decreased triacylglycerol synthesis within hepatocytes due to decreased diacylglycerol acyltransferase (DGAT) activity has
been suggested to be an important mechanism by which diets rich in fish oil lower plasma triacylglycerol levels. New findings
suggest that eicosapentaenoic acid (EPA), and not docosahexaenoic acid (DHA), lowers plasma triacylglycerol by increased mitochondrial
fatty acid oxidation and decreased availability of fatty acids for triacylglycerol synthesis. To contribute to the understanding
of the triacylglycerol-lowering mechanism of fish oil, the different metabolic properties of EPA and DHA were studied in rat
liver parenchymal cells and isolated rat liver organelles. EPA-CoA was a poorer substrate than DHA-CoA for DGAT in isolated
rat liver microsomes, and in the presence of EPA, a markedly lower value for the triacyl[3H]glycerol/diacyl[3H]glycerol ratio was observed. The distribution of [1-14C]palmitic acid was shifted from incorporation into secreted glycerolipids toward oxidation in the presence of EPA (but not
DHA) in rat liver parenchymal cells. [1-14C]EPA was oxidized to a much greater extent than [1-14C]DHA in rat liver parenchymal cells, isolated peroxisomes, and especially in purified mitochondria. As the oxidation of EPA
was more effective and sensitive to the CPT-I inhibitor, etomoxir, when measured in a combination of both mitochondria and
peroxisomes, we hypothesized that both are involved in EPA oxidation, whereas DHA mainly is oxidized in peroxisomes. In rats,
EPA treatment lowered plasma triacylglycerol and increased hepatic mitochondrial fatty acid oxidation and carnitine palmitoyltransferase
(CPT)-I activity in both the presence and absence of malonyl-CoA. Whereas only EPA treatment increased the mRNA levels of
CPT-I, DHA treatment increased the mRNA levels of peroxisomal fatty acyl-CoA oxidase and fatty acid binding protein more effectively
than EPA treatment. In conclusion, EPA and DHA affect cellular organelles in relation to their substrate preference. The present
study strongly supports the hypothesis that EPA, and not DHA, lowers plasma triacylglycerol by increased mitochondrial fatty
acid oxidation. 相似文献
93.
Allergy and respiratory health effects of dampness and dampness‐related agents in schools and homes: a cross‐sectional study in Danish pupils
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G. J. Holst A. Høst G. Doekes H. W. Meyer A. M. Madsen K. B. Plesner T. Sigsgaard 《Indoor air》2016,26(6):880-891
Little is known about the health effects of school‐related indoor dampness and microbial exposures. In this study, we investigated dampness and dampness‐related agents in both homes and schools and their association with allergy and respiratory health effects in 330 Danish pupils. Classroom dampness was identified based on technical inspection and bedroom dampness on parents' self‐report. Classroom and bedroom dust was analyzed for seven microbial components. Skin prick testing determined atopic sensitization. Lung function was expressed as z‐scores for forced expiratory volume in one‐second (zFEV1), forced vital capacity (zFVC) and the ratio zFEV1/zFVC using GLI‐2012 prediction equations. The parents reported children's allergies, airway symptoms, and doctor‐diagnosed asthma. High classroom dampness, but not bedroom dampness, was negatively associated with zFEV1 (β‐coef. ?0.71; 95% CI ?1.17 to ?0.23) and zFVC (β‐coef. ?0.52; 95% CI ?0.98 to ?0.06) and positively with wheezing (OR 8.09; 95% CI 1.49 to 43.97). No consistent findings were found between any individual microbial components or combination of microbial components and health outcomes. Among other indoor risk factors, environmental tobacco smoke (ETS) decreased zFEV1 (β‐coef. ?0.22; 95% CI ?0.42 to ?0.02) and zFEV1/zFVCratio (β‐coef. ?0.26; 95% CI ?0.44 to ?0.07) and increased upper airway symptoms (OR 1.66; 95% CI 1.03–2.66). In conclusion, dampness in classrooms may have adverse respiratory health effects in pupils, but microbial agents responsible for this effect remain unknown. 相似文献
94.
95.
Lynnette D. Madsen 《Journal of Electroceramics》2009,22(1-3):2-7
International collaboration can be an integral part of a research project. It can add scientific expertise or interdisciplinarity, enhance equipment and facilities; and strengthen the training and education of students. In recognition of these benefits, the National Science Foundation (NSF) of the United States has supported researchers in many different modes. One option for ceramists is the Materials World Network (MWN) program. Today, approximately 24% of the active projects in the Ceramics Program (CER) of NSF’s Division of Materials Research (DMR) are funded through the MWN program (or its precursors). Each project includes participants from two or more countries and collectively they include researchers from 16 countries. This year an additional 33 ceramic proposals, including renewals, were merit-reviewed in panels and seven awards were made. Characteristics of the best proposals include synergistic pairings of interests and expertise between international partners, detailed plans for student exchanges, activities to broaden the participation of groups under-represented in science, and cutting-edge creative and original research ideas. As well, NSF supports many international activities through the Office of International Science and Engineering (OISE) including regional opportunities. Instrumentation and facilities supported by NSF, particularly those in Materials Science and Engineering, are often accessible on an international basis. 相似文献
96.
Reynaldo Moreno Giovanna M. Aita Lee Madsen Dina L. Gutierrez Shaomian Yao Barry Hurlburt Suzanne Brashear 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2013,88(5):948-957
BACKGROUND: Microalgae, with both high biomass productivity and oil content, are regarded as attractive candidates for the production of alternative biodiesel as well as for CO2 biofixation. In the present study, four microalgal strains native to southeastern Louisiana's waters were isolated and identified to evaluate their potential for the production of biodiesel. Selected strains were identified through genomic DNA in sequencing of either 16S rRNA or 18S rRNA genes followed by lipid and fatty acid content characterization and quantification. RESULTS: High correlation was found with known nucleotide sequence identities at 98% with Sellaphora pupula, and 99% with Synechococcus sp., Chlorella sorokiniana, Scenedesmus abundans, and Chlorella vulgaris (control). The fatty acid profiles of these organisms changed when using 5% CO2 aeration. Total fatty acids (TFA) decreased from 20.63 to 17.62, 54.83 to 24.4, and 29.82 to 23.99 g kg?1 in Synechococcus sp., Sellaphora pupula and Chlorella sorokiniana, respectively. TFA increased from 14.14 to 31.49 and 15.14 to 47.52 g kg?1 dry biomass in Scenedesmus abundans and Chlorella vulgaris (control), respectively. CONCLUSION: Chlorella sorokiniana, with a lower C18:3 and the highest biomass yield at 5% CO2 aeration, was found to be the best candidate for biodiesel production. © 2012 Society of Chemical Industry 相似文献
97.
Plant fibre composites contain typically a relatively large amount of porosity which influences their performance. A model, based on a modified rule of mixtures, is presented to include the influence of porosity on the composite stiffness. The model integrates the volumetric composition of the composites with their mechanical properties. The fibre weight fraction is used as an independent parameter to calculate the complete volumetric composition. A maximum obtainable stiffness of the composites is calculated at a certain transition fibre weight fraction, which is characterised by a best possible combination of high fibre volume fraction and low porosity. The model is validated with experimental data from the literature on several types of composites. A stiffness diagram is presented to demonstrate that the calculations can be used for tailoring and design of composites with a given profile of properties. 相似文献
98.
99.
Rantz MJ Petroski GF Madsen RW Mehr DR Popejoy L Hicks LL Porter R Zwygart-Stauffacher M Grando V 《The Joint Commission journal on quality improvement》2000,26(2):101-110
BACKGROUND: Determining meaningful thresholds to reinforce excellent performance and flag potential problem areas in nursing home care is critical for preparing reports for nursing homes to use in their quality improvement programs. This article builds on the work of an earlier panel of experts that set thresholds for quality indicators (QIs) derived from Minimum Data Set (MDS) assessment data. Thresholds were now set for the revised MDS 2.0 two-page quarterly form and Resource Utilization Groups III (RUGS III) quarterly instrument. SETTING THRESHOLDS: In a day-long session in October 1998, panel members individually determined lower (good) and upper (poor) threshold scores for each QI, reviewed statewide distributions of MDS QIs, and completed a follow-up Delphi of the final results. REPORTING MDS QIS FOR QUALITY IMPROVEMENT: The QI reports compiled longitudinal data for all residents in the nursing home during each quarter and cumulatively displayed data for five quarters for each QI. A resident roster was provided to the nursing home so that the quality improvement team could identify the specific residents who developed the problems defined by each QI during the last quarter. Quality improvement teams found the reports helpful and easy to interpret. SUMMARY AND CONCLUSIONS: As promised in an earlier report, to ensure that thresholds reflect current practice, research using experts in a panel to set thresholds was repeated as needed. As the MDS instrument or recommended calculations for the MDS QIs change, thresholds will be reestablished to ensure a fit with the instrument and data. 相似文献
100.
VL Cressman EM Hicks WK Funkhouser DC Backlund BH Koller 《Canadian Metallurgical Quarterly》1998,19(6):853-866
In the cystic fibrosis (CF) patient, lung function decreases throughout life as a result of continuous cycles of infection, particularly with Pseudomonas aeruginosa and Staphylococcus aureus. The mechanism underlying the pathophysiology of the disease in humans has not been established. However, it has been suggested that abnormal, tenacious mucus, resulting perhaps from improper hydration from loss of Cl- secretion via the cystic fibrosis transmembrane conductance regulator (CFTR) protein, impairs clearance of bacteria from the CF airway and provides an environment favorable to bacterial growth. If this hypothesis is correct, it could explain the absence of respiratory disease in CFTR-deficient mice, since mice have only a single submucosal gland and display few goblet cells in their lower airways, even when exposed to bacteria. To test this hypothesis further, we induced allergic airway disease in CFTR-deficient mice. We found that induction of allergic airway disease in mice, unlike bacterial infection, results in an inflammatory response characterized by goblet cell hyperplasia, increased mucin gene expression, and increased production of mucus. However, we also found that disease progression and resolution is identical in Cftr-/- mice and control animals. Furthermore, we show that the presence of mucus in the Cftr-/- airway does not lead to chronic airway disease, even upon direct inoculation with S. aureus and P. aeruginosa. Therefore, factors in addition to the absence of high levels of mucus secretion protect the mouse from the airway disease seen in human CF patients. 相似文献