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Diagnostic accuracy of tests for Helicobacter pylori in an Alaska Native population

World j.urnal of Gastroenterology 2011年第42期17卷 4682-4688页

作者： Dana L Bruden Michael G Bruce karen M Miernyk j.lie Morris Debby Hurlburt Thomas W Hennessy Helen Peters Frank Sacco Alan j.Parkinson Brian j.McMahon Arctic Investigations Program Division of Preparedness and Emerging InfectionsNational Center for Emerging Zoonoses and Infectious DiseasesCenters for Disease Control and Prevention Alaska Native Tribal Health Consortium Anchorage

AIM： TO evaluate the accuracy of two non-invasive tests in a population of Alaska Native persons. High rates of Helicobacter pylori （H. pylon] infection, H. pyIori treatment failure, and gastric cancer in this population necessitate documentation of infection status at multiple time points over a patient＇s *** test, 13C urea breath test （UBT）, and immunoglobulin G antibodies to H. pylori in serum. The performances of 13C-UBT and antibody test were compared to a gold standard defined by a positive H. pylori test by culture or, in case of a negative culture result, by positive histology and a positive rapid urease test.RESULTS： The sensitivity and specificity of the 13C- UBT were 93% and 88%, respectively, relative to the gold standard. The antibody test had an equivalent sensitivity of 93% with a reduced specificity of 68%. The false positive results for the antibody test were associated with previous treatment for an H. pylorlinfection [relative risk （RR） = 2.8]. High levels of antibodies to H. py/or/were associated with chronic gastritis and male gender, while high scores in the 13C-UBT test were associated with older age and with theH. pylori bacteria load on histological examination （RR = 4.4）. CONCLUSION： The 13C-UBT outperformed the antibody test for H. pylori and could be used when a noninvasive test is clinically necessary to document treatment outcome or when monitoring for reinfection.

关键词： Urea breath test Antibody test Sensitivity Specificity

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Post-traumatic stress disorder among homeless adults in Poland: Prevalence and predictors

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Open j.urnal of Psychiatry 2014年第1期4卷 9-15页

作者： Anna Bokszczanin Paul A. Toro karen L. Hobden Carolyn j. Tompsett Department of Psychology Bowling Green State University Ohio USA Department of Psychology University of Windsor Windsor Canada Institute of Psychology Opole University Opole Poland

BACKGROUND: Symptoms of Post-Traumatic Stress Disorder (PTSD) have often been found in studies on homeless people, due to high rates of traumatic experiences. Most research on homelessness has been conducted in North America and Western Europe. However there are many social and cultural factors which can impact the prevalence and number of PTSD symptoms. AIMS: This study sought to determine the prevalence and predictors of trauma and PTSD symptoms among homeless adults in an Eastern European nation (Poland). METHOD: Randomly chosen residents of shelters were interviewed (N = 200). The respondents were asked about symptoms of PTSD, alcohol abuse/dependence, depression symptoms and perceived social support. RESULTS: The data indicated that 30% of the homeless sample were victims of traumatic events, 22% showed at least one PTSD symptom, and 7% met criteria for a lifetime diagnosis of PTSD. Symptoms of PTSD were the most common among those who had symptoms of alcohol abuse/ dependence and depression. CONCLUSION: The study’s findings support the need to attend to mental disorders such as PTSD when addressing the array of needs of homeless people.

关键词： Homelessness PTSD Trauma Depression Alcohol Use Social Support Poland

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A Pragmatic Approach to Coping with Matrix Effects during ICP-MS Analysis of Trace Elements in Silicate Rocks and Calibration of REE Interferences

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j.urnal of Geoscience and Environment Protection 2019年第3期7卷 82-125页

作者： C. Michael B. Henderson Paul R. Lythgoe karen j. Theis School of Earth and Environmental Sciences (SEES) University of Manchester Manchester UK ASTec Sci-Tech Daresbury Laboratory Science and Technology Funding Council Warrington UK

Operating an Agilent 7700X ICP-MS spectrometer under robust plasma conditions (1550 W) with a He-filled octopole collision cell and analysing solutions (?1 total dissolved solids) still suffered analyte peak suppression due to matrix effects. International reference rocks BCR-1, BHVO-1, AGV-1, G-2 and BCR-2 all showed count rate reductions for 36 elements (mass range 7Li to 238U) averaging ~10% but with no dependence on isotope mass. Use of an internal standard (103Rh) and/or using a ten-fold dilution of sample solutions reduced these effects but problems with reduced count rates combined with larger errors for some elements introduced other problems. The best approach was to normalise the count rates for each element in the other samples against those for BCR-1 as an external standard;thus the count suppression due to the matrix effect is corrected for each individual element. This approach provides standardization “traceability” in line with the ERM ISO/IEC requirement. Experiments are also reported on quantifying the proportions of Ba and selected REE oxide/hydroxide components versus parent isotopes (XO/X and XOH/X). This information is essential for correcting peak interferences on higher mass number REE for the rock samples, and equations are developed to use measured CeO/Ce and CeOH/Ce ratios to predict such values for any other member of the REE suite. Concentrations obtained show excellent agreement with recommended values for the international reference materials especially for the REE. Robust data are also provided for two other standard rocks: nepheline syenite STM-1 and quartz syenite CAAS-1;the latter shows exceptional enrichments of Zr, REE, Th, and U.

关键词： ICP-MS Dilution Minimises Matrix Effects BCR-1 as an External Standard New Analyses for STM-1 and CAAS-1 Calibration of X-O/OH Interferences on REE Elements

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Microencapsulated paraffin as a tribological additive for advanced polymeric coatings

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Friction 2023年第10期11卷 1939-1952页

作者： Reza GHEISARI Mariela VAZQUEZ Vasilis TSIGKIS Ali ERDEMIR karen L.WOOLEY Andreas A.POLYCARPOU j.Mike Walker’66 Department of Mechanical Engineering Texas A&M UniversityCollege Station 77843USA Department of Chemistry Texas A&M UniversityCollege Station 77843USA Department of Materials Science&Engineering Texas A&M UniversityCollege Station 77843USA Department of Chemical Engineering Texas A&M UniversityCollege Station 77843USA

Numerous tribological applications,wherein the use of liquid lubricants is infeasible,require adequate dry *** the use of polymers as an effective solution for dry sliding tribological applications,their poor wear resistance prevents the utilization in harsh industrial *** methods are typically implemented to tackle the poor wear performance of polymers,however sacrificing some of their mechanical/tribological ***,we discussed the introduction of a novel additive,namely microencapsulated phase change material(MPCM)into an advanced polymeric ***,paraffin was encapsulated into melamine-based resin,and the capsules were dispersed in an aromatic thermosetting co-polyester(ATSP)*** found that the MPCM-filled composite exhibited a unique tribological behavior,manifested as“zero wear”,and a super-low coefficient of friction(COF)of *** developed composite outperformed the state-of-the-art polytetrafluoroethylene(PTFE)-filled coatings,under the experimental conditions examined herein.

关键词： microencapsulated phase change material(MPCM) friction reduction additive advanced polymeric coating

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G-Quadruplex(G4) Motifs in the Maize(Zea mays L.) Genome Are Enriched at Specific Locations in Thousands of Genes Coupled to Energy Status,Hypoxia,Low Sugar,and Nutrient Deprivation

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j.urnal of Genetics and Genomics 2014年第12期41卷 627-647页

作者： Carson M.Andorf Mykhailo Kopylov Drena Dobbs karen E.Koch M.Elizabeth Stroupe Carolyn j.Lawrence Hank W.Bass USDA-ARS Corn Insects and Crop Genetics Research Unit Iowa State University Department of Computer Science Iowa State University Institute of Molecular Biophysics Florida State University Department of Genetics Development and Cell BiologyIowa State University Plant Molecular and Cellular Biology Program Horticultural Sciences DepartmentGenetics InstituteUniversity of Florida Department of Biological Science Florida State University Department of Agronomy Iowa State University

The G-quadruplex （G4） elements comprise a class of nucleic acid structures formed by stacking of guanine base quartets in a quadruple helix. This （34 DNA can form within or across single-stranded DNA molecules and is mutually exclusive with duplex B-form DNA. The reversibility and structural diversity of G4s make them highly versatile genetic structures, as demonstrated by their roles in various functions including telomere metabolism, genome maintenance, immunoglobulin gene diversification, transcription, and translation. Sequence motifs capable of forming G4 DNA are typically located in telomere repeat DNA and other non-telomeric genomic loci. To investigate their potential roles in a large-genome model plant species, we computationaily identified 149,988 non-telomeric G4 motifs in maize （Zea mays L., B73 AGPv2）, 29% of which were in non-repetitive genomic regions. G4 motif hotspots exhibited non-random enrichment in genes at two locations on the antisense strand, one in the 5~ UTR and the other at the 5~ end of the first intron. Several genic G4 motifs were shown to adopt sequence-specific and potassium-dependent G4 DNA structures in vitro. The G4 motifs were prevalent in key regulatory genes associated with hypoxia （group VII ERFs）, oxidative stress （D j.1/GATasel）, and energy status （AMPK/ SnRK） pathways. They also showed statistical enrichment for genes in metabolic pathways that function in glycolysis, sugar degradation, inositol metabolism, and base excision repair. Collectively, the maize G4 motifs may represent conditional regulatory elements that can aid in energy status gene responses. Such a network of elements could provide a mechanistic basis for linking energy status signals to gene regulation in maize, a model genetic system and maj.r world crop species for feed, food, and fuel.

关键词： Maize G-quadruplex G4 Hypoxia Sucrose synthase

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Imidoyl Radicals for the Synthesis of Chromenoquinolines and Naphthyridines

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International j.urnal of Organic Chemistry 2018年第3期8卷 319-334页

作者： karen C. Vizcaíno-Escobedo j. Adrián Sánchez-Carrillo Martha Albores-Velasco Facultad de Química Universidad Nacional Autónoma de México Ciudad Universitaria Ciudad de México México

The stability of imidoyl radicals prepared from 2-(2-alkenyloxy)-phenyl selenoimidates and 2-(2-allylamino)-phenyl selenoimidates and their intramolecular free radical cyclization through the slow addition of tri-N-butyltin hydride and AIBN to obtain 4-chromanones and 4-quinolones were studied. The extension of the methodology to N-phenyl substituted imidoyl selenoates produced tandem cyclizations of the imidoyl radical with the allyl substituent, followed for a second cyclization of the intermediate radical with the aromatic substituent to produce dihydro-chromenoquinolines or tetrahy-dro-dibenzonaphtyridines. Further oxidation with DDQ produced: 6H-chromeno [4,3,b] quinoline and 7-methyl-6H-chromenoquinoline from 2-alkenylamino-phenylbenzamide and 5,6-dihydro-dibenzo [b,h][1,6] naphthyridine and 5,6-dihydro-7-methyl-dibenzo [b,h][1,6] naphthyridine from 2-2-(alkylamino)-N-phenylbenzamides. The cyclization of 2-(N,***)-N-phenylnicotinamide selenoate obtained from 2-aminonicotinic acid, produced 5,6-dihidro-benzo[b]pyrido2,3-h] [1,6] naphthyridine.

关键词： Imidoyl Radicals Quinolones Chromenoquinolines Naphthyridines Dibenzonaphtyridines

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Land application of spent gypsum from ditch filters: phosphorus source or sink?

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Agricultural Sciences 2011年第3期2卷 364-374页

作者： karen L. Grubb j.shua M McGrath Chad j. Penn Ray B. Bryant Department of Environmental Science and Technology University of Maryland College Park PA USA Department of Plant and Soil Sciences Oklahoma State University Stillwater USA USDA-Agricultural Research Service College Park PA USA USDA-National Institute of Food and Agriculture Washington D.C. USA

Agricultural drainage ditches can provide a direct connection between fields and surface waters, and some have been shown to deliver high loads of phosphorus (P) to sensitive water bodies. A potential way to reduce nutrient loads in drainage ditches is to install filter structures containing P sorbing materials (PSMs) such as gypsum to remove P from ditch flow. The obj.ctive of this study was to determine the effect of land-application of gypsum removed from such filters on soil P forms and concentrations. Gypsum was saturated at two levels on a mass basis of P and applied to two soils of contrasting texture, a silt loam and a sandy loam and applied at both a high and low rate. The treated soils were incubated in the laboratory at 25oC, and samples were collected at 1, 7, and 119 days after initiation. Soil type, time after application, gypsum rate, and P saturation level all had a significant impact on soil P forms and concen-trations. However, it appears that land application of spent filter gypsum at realistic rates would have little effect on soluble P concentrations in amended soils.

关键词： Phosphorus Sorbing Materials Gypsum Ditch Filter

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Evaluation of Size Structure in Freshwater Cyanobacterial Populations: Methods to Quantify Risk Associated with Changes in Biomass and Microcystin Concentrations

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j.urnal of Water Resource and Protection 2019年第6期11卷 810-829页

作者： Nancy j. Leland j.mes F. Haney Kristin Conte karen Malkus-Benj.min Bryan Horsely Lim-Tex North Andover MA USA Department of Zoology University of New Hampshire Durham NH USA Manchester Water Works Manchester NH USA Town of Barnstable Barnstable MA USA Association to Preserve Cape Cod Dennis MA USA

Cyanobacterial populations in surface waters, including drinking water supplies and recreational waters, represent an ever present challenge for resource managers. As communities continuously respond to external and internal processes, dynamic profiles of composition, dominance, growth and toxigenicity emerge. In this study measures of size structure and biomass, quantified using light microscopy and fluorometry, were used to estimate microcystin concentrations through linear regression analysis. Toxigenic profiles using cyanobacterial biomass were developed for lakes dominated by Microcystis spp. and Dolichospermum spp., influenced by both genus-specific pigment concentrations as well as microcystin concentrations. Community composition (Log %MIC) and biomass were used to describe microcystin concentrations in mixed assemblages, where composition was the first input variable. The accessory photopigment phycocyanin was used to describe the linear relationship between the daily growth and net microcystin production rates in the bloom-forming Microcystis spp. samples, suggesting that this size-fractionated sample may provide indications of potential toxigenicity in the whole lake water sample. Future investigations using fluorometric evaluation of cyanobacterial populations could provide additional applications and metrics for use by resource managers to quantify risk association with elevated cyanotoxin concentrations.

关键词： Microcystis Dolichospermum Phycocyanin Microcystins Growth Rates

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The practical guide to proj.ct management documentation

The practical guide to project management documentation

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1000年

作者： j.hn j. Rakos with karen Dhanraj.... [et al.].

来源：畅想之星图书光盘版（南... 评论

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Vegetables, Herbs and Spices: The Importance of Family and Tasting

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Health 2016年第14期8卷 1554-1565页

作者： Pamela A. Heinrichs Cassandra j. Nikolaus Brenna Ellison Sharon M. Nickols-Richardson karen Chapman-Novakofski University of Illinois at Urbana-Champaign Champaign IL USA Currently Address: The Hersey Company Hershey PA USA

Obj.ctive: To explore why and how consumers utilize vegetables, herbs and spices. Methods: Focus groups were conducted with adult participants (n = 54) to determine attitudes, self-efficacy, and behaviors related to liking and usage of vegetables, herbs and spices as well as strategies to increase vegetable intake. Results: Seasonal availability, and family-centered memories and practices were motivation for vegetable intake. A diverse number of vegetables (n = 39) were listed as favorites based on taste and versatility, but seasonings were not commonly included in responses regarding preparation. Participants felt that vegetable dish names should reflect ingredients explicitly;that seasonings enhanced vegetable flavors;and that salt and pepper were most commonly used seasonings. The preferred strategy to increase vegetable consumption was through tasting or sampling opportunities;seasoning use was not mentioned. However, participants perceived that suggestions or demonstrations on how to prepare vegetables at home would be helpful. Personal gardens were mentioned frequently, but were not connected to strategies for increasing intake. Conclusions and Implications: Vegetable intake has a family focus that should be emphasized to increase intake. Efforts to increase intake could emphasize flavor and versatile preparation methods through tasting opportunities or educational demonstrations.

关键词： Dietary Habits Focus Groups Vegetables Spices Herbs

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