Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Fraction

  • acetate fraction
  • acid fraction
  • active fraction
  • alkaloid fraction
  • amorphous fraction
  • antigen fraction
  • area fraction
  • aromatic fraction
  • attributable fraction
  • baryon fraction
  • bioavailable fraction
  • biodegradable fraction
  • bone area fraction
  • bone volume fraction
  • carbohydrate fraction
  • carbon fraction
  • casein fraction
  • cell fraction
  • cell-free fraction
  • cellular fraction
  • certain fraction
  • chemical fraction
  • clay fraction
  • cloud fraction
  • considerable fraction
  • constant fraction
  • crystalline fraction
  • cure fraction
  • cytoplasmic fraction
  • cytoskeletal fraction
  • cytosolic fraction
  • density fraction
  • different fraction
  • different volume fraction
  • ejection fraction
  • ethyl acetate fraction
  • extracellular fraction
  • extraction fraction
  • fat fraction
  • fiber volume fraction
  • filler volume fraction
  • filling fraction
  • filtration fraction
  • fixed fraction
  • free fraction
  • gel fraction
  • greater fraction
  • growth fraction
  • heavy fraction
  • hexane fraction
  • high fraction
  • high volume fraction
  • humic fraction
  • humin fraction
  • igg fraction
  • immature platelet fraction
  • immature reticulocyte fraction
  • important fraction
  • increased fraction
  • increasing fraction
  • individual fraction
  • insoluble fraction
  • ionization fraction
  • labile fraction
  • large fraction
  • larger fraction
  • largest fraction
  • leave ventricular ejection fraction
  • light fraction
  • lipid fraction
  • lipoprotein fraction
  • liquid fraction
  • liver s9 fraction
  • low ejection fraction
  • low fraction
  • lower ejection fraction
  • lower fraction
  • lv ejection fraction
  • m fraction
  • major fraction
  • mass fraction
  • mean ejection fraction
  • mean lv ejection fraction
  • membrane fraction
  • microsomal fraction
  • mineral fraction
  • minor fraction
  • mitochondrial fraction
  • molar fraction
  • mole fraction
  • molecular weight fraction
  • mw fraction
  • negative fraction
  • neutral fraction
  • nitrogen fraction
  • normal ejection fraction
  • nuclear fraction
  • oil fraction
  • one fraction
  • organic carbon fraction
  • organic fraction
  • other fraction
  • oxygen fraction
  • p fraction
  • packing fraction
  • particle fraction
  • particle size fraction
  • particle volume fraction
  • particle-size fraction
  • particulate fraction
  • peptide fraction
  • phase fraction
  • phenolic fraction
  • phospholipid fraction
  • phosphorus fraction
  • plasma fraction
  • plasma membrane fraction
  • platelet fraction
  • polar fraction
  • polymer fraction
  • polysaccharide fraction
  • population attributable fraction
  • protein fraction
  • purified fraction
  • raft fraction
  • recombination fraction
  • reduced ejection fraction
  • regurgitant fraction
  • reticulocyte fraction
  • right ventricular ejection fraction
  • rv ejection fraction
  • s-phase fraction
  • s9 fraction
  • sampling fraction
  • sand fraction
  • sediment fraction
  • several fraction
  • shortening fraction
  • significant fraction
  • size fraction
  • small fraction
  • smaller fraction
  • soc fraction
  • soil fraction
  • solid fraction
  • solid volume fraction
  • soluble fraction
  • solvent fraction
  • sperm fraction
  • subcellular fraction
  • substantial fraction
  • supernatant fraction
  • surviving fraction
  • synaptosomal fraction
  • tiny fraction
  • trabecular bone volume fraction
  • twin fraction
  • various fraction
  • ventricular ejection fraction
  • void fraction
  • volatile fraction
  • volume fraction
  • volumetric fraction
  • water fraction
  • water-soluble fraction
  • weight fraction

  • Terms modified by Fraction

  • fraction collection
  • fraction decreased
  • fraction increase
  • fraction isolated
  • fraction ratio

  • Selected Abstracts


    ABSTRACT Fatty acids (free and esterified), diglycerides, peroxides and total sterols were determined in a vegetable cream. Cream samples were analyzed when fresh and after storage for 3 and 6 months at 4, 15, 30C and room temperature (10,25C). The product showed a higher amount of unsaturated fatty acids (,50% of total fatty acids) with respect to milk fat and a low level of cholesterol (<0.01%). The phytosterol content (,14 mg/100 g of cream) was not high enough to contribute to a decrease in cholesterolemia. Lipid oxidation remained low during storage (peroxides: 2.0,3.0 meq O2/kg of fat), but a small increase was observed at room temperature after 6 months (about 6.0 meq O2/kg of fat). Free fatty acids never exceeded 0.3% of fat. Storage at 4C and 15C delayed lipolysis in comparison to storage at 30C and room temperature. PRACTICAL APPLICATIONS The analysis of a vegetable cream demonstrated that it was a shelf-stable product, showing a high stability toward lipid oxidation and lipolysis. Such a product might be employed as vehicle for healthy fat compounds like long-chain polyunsaturated fatty acids, phytosterols and fat-soluble vitamins. [source]


    ABSTRACT This study aimed to check the hypothesis that aroma concentration in the aqueous phase of an oil-in-water emulsion controlled the odor intensity of single aroma compounds. A set of flavored oil-in-water emulsions, prepared according to a 22 experimental design (aroma concentration, oil volume fraction) with two central points, was assessed for odor intensity by a 24-member panel during four sessions. In each session, three of the four-studied aroma molecules (benzaldehyde, ethyl butyrate, linalool and acetophenone) were investigated. Whatever the aroma, the experimental data showed that the oil volume fraction of the emulsion (from 0.12 to 0.48) did not influence the odor intensity. For each emulsion composition, aroma concentrations at equilibrium in both phases were calculated using the oil-water partition coefficient of the compound. Odor intensities, estimated from aroma concentration in the aqueous phase using previously reported modeling of odor intensity above water solutions, were then compared to experimental data. It is confirmed that the perceived odor intensity is governed by the aroma concentration in the aqueous phase at the time of the trial and not by the averaged apparent concentration in the emulsion. [source]


    ABSTRACT This article presents the influence of cell size and cell wall volume fraction on the failure parameters of potato tuber and carrot tissue. Confocal scanning laser microscope was used for obtaining images of the cell structure of the tissues. The mean cell face area and the cell wall volume fraction obtained from the images was compared with work to failure, failure stress, failure strain and secant modulus obtained in a compression test of potato and carrot tissue at two strain rates. Bigger cells and less amount of cell wall material weakened the tissue, which was visible as a linear decrease in the parameters: work to failure, failure stress and failure strain. There were differences between potato and carrot in the secant modulus. For carrot, the secant modulus changed with microstructural parameters, whereas for potato, the secant modulus did not depend on these values. The strain rate decreases all the failure properties for potato. For carrot, only the work to failure was affected by the strain rate. [source]


    Chris J. Lloyd
    Summary This paper aims to estimate the false negative fraction of a multiple screening test for bowel cancer, where those who give negative results for six consecutive tests do not have their true disease status verified. A subset of these same individuals is given a further screening test, for the sole purpose of evaluating the accuracy of the primary test. This paper proposes a beta heterogeneity model for the probability of a diseased individual ,testing positive' on any single test, and it examines the consequences of this model for inference on the false negative fraction. The method can be generalized to the case where selection for further testing is informative, though this did not appear to be the case for the bowel-cancer data. [source]


    ABSTRACT Our previous study showed that in vitro pepsin digestibility of Chinese tartary buckwheat protein was relatively low compared to those of other edible seeds. In vitro pepsin digestibilities of four protein fractions of tartary buckwheat, microstructure and molecular weight (MW) distributions of hydrolysates were investigated. In vitro pepsin digestion assay showed that the digestibilities of tartary buckwheat protein fractions were albumin (81.20%), globulin (79.56%), prolamin (66.99%) and glutelin (58.09%). Scanning electron microscopy showed that albumin and globulin fractions were digested by pitting from the outer surface to the inner part and were more digestible, while prolamin and glutelin fractions resisted digestion because only the outer surfaces of their protein bodies were digested and the interior was protected. MW distribution of the hydrolysates from the four protein fractions was determined by high-performance liquid chromatography. The hydrolysates of albumin mainly consisted of polypeptides with lower MW. The hydrolysates of glutelin had larger polypeptides together with small and medium-sized peptide fractions. [source]

    The Effect of Erythropoietin on Exercise Capacity, Left Ventricular Remodeling, Pressure-Volume Relationships, and Quality of Life in Older Patients With Anemia and Heart Failure With Preserved Ejection Fraction

    Rose S. Cohen MD
    A prospective, open-label, 3-month study was conducted to evaluate the feasibility and short-term clinical effect of subcutaneous erythropoietin injections in patients with anemia and heart failure with preserved ejection fraction (ejection fraction, 55%±2%). Using a dose-adjusted algorithm to effect a rate of rise in hemoglobin not to exceed 0.4 g/dL,/wk, hemoglobin (10.8±0.3 to 12.2±0.3 g/dL) and red blood cell volume (1187±55 to 1333±38 mL) increased with an average weekly dose of 3926 units. Functional measures increased from baseline (6-minute walk test [289±24 to 331±22 m], exercise time [432±62 to 571±51 s], and peak oxygen consumption [8.2±0.7 to 9.4±0.9 mL/kg/min], all P<.05). End-diastolic volume declined significantly (8% volumetric decrease, 108±3 to 100±3 mL, P =.03), but there were no significant changes in left ventricular mass or estimated left ventricular end-diastolic pressure. Pressure-volume analysis demonstrated a reduction in ventricular capacitance at an end-diastolic pressure of 30 mm Hg without significant changes in contractile state. Congest Heart Fail. 2010;16:96,103. © 2009 Wiley Periodicals, Inc. [source]

    Perioperative Outcome and Long-Term Mortality for Heart Failure Patients Undergoing Intermediate- and High-Risk Noncardiac Surgery: Impact of Left Ventricular Ejection Fraction

    Kirsten O. Healy MD
    The impact of left ventricular ejection fraction (LVEF) on outcome in patients with heart failure (HF) undergoing noncardiac surgery has not been extensively evaluated. In this study, 174 patients (mean age, 75±12 years, 47% male, mean LVEF (47%±18%) underwent intermediate- or high-risk noncardiac surgery. Patients were stratified by LVEF, and adverse perioperative complications were identified and compared. Adverse perioperative events occurred in 53 patients (30.5%), including 14 (8.1%) deaths within 30 days, 26 (14.9%) myocardial infarctions, and 44 (25.3%) HF exacerbations. Among the factors associated with adverse perioperative outcomes in the first 30 days were advanced age (>80 years), diabetes, and a severely decreased LVEF (<30%). Long-term mortality was high, and Cox proportional hazards analysis demonstrated that LVEF was an independent risk factor for long-term mortality. Congest Heart Fail. 2010;16:45,49. © 2009 Wiley Periodicals, Inc. [source]

    The Cardio-Renal-Anemia Syndrome in Elderly Subjects With Heart Failure and a Normal Ejection Fraction: A Comparison With Heart Failure and Low Ejection Fraction

    Rose S. Cohen MD
    The prevalence and severity of anemia and renal dysfunction in heart failure patients with a normal ejection fraction (HFNEF) is uncharacterized. Two hundred eighty-five consecutive patients admitted to a community hospital with heart failure were stratified by the presence or absence of anemia and a normal or reduced ejection fraction. Comparisons of clinical variables were performed. In this sample, 62% of subjects were anemic, with no difference between those with a normal and a reduced ejection fraction (63% vs. 61%). Anemic HFNEF subjects had a lower glomerular filtration rate (37±21 mL/min vs. 52±35 mL/min; p<0.05) and more severe self-reported symptom scores than nonanemic HFNEF subjects. Multivariate analysis confirmed the association of renal dysfunction and anemia. The authors conclude that the degree and magnitude of anemia in elderly inpatients with heart failure does not differ by ejection fraction. Worse symptoms and more severe renal dysfunction were seen in HFNEF subjects with anemia than in HFNEF subjects without anemia. [source]

    Atrial Septal Defect Occluder Device Huge Thrombus in Patient with Low Ejection Fraction

    ECHOCARDIOGRAPHY, Issue 8 2010
    Murat Yuce M.D.
    (Echocardiography 2010,27:E96-E97) [source]

    Measurement of Left Ventricular Ejection Fraction by Real Time 3D Echocardiography in Patients with Severe Systolic Dysfunction: Comparison with Radionuclide Angiography

    ECHOCARDIOGRAPHY, Issue 1 2010
    Hajo Müller M.D.
    Aim: Measurement of left ventricular ejection fraction (LVEF) using real time 3D echocardiography (3DE) has been performed in subjects with preserved or modestly reduced systolic function. Our aim was to evaluate this technique in the subset of patients with severe systolic dysfunction. Methods and results: Consecutive patients with LVEF less than 0.35 at two-dimensional echocardiography were included. LVEF obtained by 3DE was compared to the value measured by radionuclide angiography (RNA). Real time full-volume 3DE was performed, with offline semiautomated measurement of LVEF using dedicated software (Cardioview RT, Tomtec) by a single observer blinded to the results of RNA. A total of 50 patients were evaluated, of whom 38 (76%, 27 males, age 69 ± 13 years) had a 3DE of sufficient quality for analysis. LVEF for this group was 0.21 ± 0.07 using 3DE and 0.27 ± 0.08 using RNA. The agreement between the two techniques was rather poor (r = 0.49; P < 0.001; 95% limits of agreements of ,0.20 to 0.09). Truncation of the apex was observed in 6 of 38 (16%) patients. Conclusion: In patients with severe systolic dysfunction, 3DE shows poor agreement for measurement of LVEF as compared to RNA. There may be underestimation of up to 20% in absolute terms by 3DE. Accordingly, the two methods are not interchangeable for the follow-up of LV function. A limitation of 3DE may, at least in part, be related to the incomplete incorporation of the apical region into the pyramidal image sector in patients with dilated hearts. (Echocardiography 2010;27:58-63) [source]

    Subtle Systolic Dysfunction May Be Associated with the Tendency to Develop Diastolic Heart Failure in Patients with Preserved Left Ventricular Ejection Fraction

    ECHOCARDIOGRAPHY, Issue 4 2009
    Hüseyin Sürücü M.D.
    Background: We looked for an answer to the question of whether diastolic heart failure (DHF) is a reality or all heart failures are systolic. Method: 300 cases (hypertensive, aged, obese, etc.), not being diagnosed DHF, with preserved left ventricular (LV) ejection fraction (EF) but having the tendency to develop DHF in future were examined. One hundred and eighty cases without exclusion criteria were selected. Cases were assigned to three groups according to noninvasively obtained pulmonary capillary wedge pressure (PCWP). Results: In cases with higher PCWP (>10 mmHg), transmitral A velocity was increased (P < 0.001) and among the pulsed wave tissue Doppler imaging (pw-TDI) parameters Ea velocity was decreased (P < 0.001) and Ea-dt was prolonged (P < 0.005). In cases with lower PCWP (<8 mmHg), transmitral E velocity was higher (P< 0.001). Furthermore, a more meaningful relationship was found between PCWP and systolic pw-TDI parameters. In all the groups, it was observed that Sa velocity was progressively decreased and Q-Sa interval was progressively prolonged as PCWP increased (for all the groups P < 0.046). Conclusion: The question whether DHF is a reality or all heart failures are systolic may be answered as follows. Subtle systolic dysfunction may be associated with the tendency to develop DHF in patients with preserved LV ejection fraction. As in systolic heart failure (EF < 45%), in patients with preserved systolic function (EF , 45%), systolic and diastolic functions may impair together. The pw-TDI method may be more sensitive than standard echocardiography parameters in detection of systolic dysfunction in cases with preserved EF. [source]

    Effect of Alcohol-Induced Septal Ablation on Left Atrial Volume and Ejection Fraction Assessed by Real Time Three-Dimensional Transthoracic Echocardiography in Patients with Hypertrophic Cardiomyopathy

    ECHOCARDIOGRAPHY, Issue 7 2008
    Fadi G. Hage M.D.
    Alcohol-induced septal ablation (AISA) is an accepted treatment for hypertrophic cardiomyopathy (HCM) patients with left ventricular (LV) outflow obstruction who are unresponsive to medical therapy. As left atrial (LA) enlargement has been correlated with increased morbidity and mortality in HCM, we assessed LA volumes and ejection fraction (EF) prior to and after AISA using real time three-dimensional (3D) transthoracic echocardiography (TTE) in 12 patients (9 women; mean age 52 ± 15 years; 11 Caucasian). All patients underwent successful AISA with no complications and their resting left ventricular outflow gradients decreased from 40.5 ± 22.2 to 9.1 ± 17.6 mmHg (P < 0.001) while their gradients with provocation decreased from 126.2 ± 31.7 to 21.8 ± 28.0 mmHg (P < 0.001). All patients showed improvements in their New York Heart Association (NYHA) functional class. Both the LA end-systolic (45.2 ± 12.9 to 37.2 ± 13.7 ml, P < 0.0001) and end-diastolic (79.6 ± 18.9 to 77.1 ± 18.6 ml, P = 0.001) volumes decreased after AISA. The LA EF increased from 43.1 ± 9.0 to 52.5 ± 8.8% (P = 0.001). The increase in LA EF correlated with the decrease in the resting left ventricular outflow gradient (R =,0.647, P = 0.03). In conclusion, 3D echocardiography can be utilized to follow LA function after AISA for HCM. AISA results in clinical improvement in patients with HCM and in improvement of LA EF that is correlated with the decrease in the left ventricular outflow gradient. [source]

    Live/Real Time Three-Dimensional Transthoracic Echocardiographic Assessment of Left Ventricular Volumes, Ejection Fraction, and Mass Compared with Magnetic Resonance Imaging

    ECHOCARDIOGRAPHY, Issue 2 2007
    Xin Qi M.D.
    Due to reliance upon geometric assumptions and foreshortening issues, the traditionally utilized transthoracic two-dimensional echocardiography (2DTTE) has shown limitations in assessing left ventricular (LV) volume, mass, and function. Cardiac magnetic resonance imaging (MRI) has shown potential in accurately defining these LV characteristics. Recently, the emergence of live/real time three-dimensional (3D) TTE has demonstrated incremental value over 2DTTE and comparable value with MRI in assessing LV parameters. Here we report 58 consecutive patients with diverse cardiac disorders and clinical characteristics, referred for clinical MRI studies, who were evaluated by cardiac MRI and 3DTTE. Our results show good correlation between the two modalities. [source]

    Accuracy of Tissue Doppler Echocardiography in the Diagnosis of New-Onset Congestive Heart Failure in Patients with Levels of B-Type Natriuretic Peptide in the Midrange and Normal Left Ventricular Ejection Fraction

    ECHOCARDIOGRAPHY, Issue 8 2006
    Stephane Arques M.D.
    Background: Based on the hypothesis that it reflects left ventricular (LV) diastolic pressures, B-type natriuretic peptide (BNP) is largely utilized as first-line diagnostic complement in the emergency diagnosis of congestive heart failure (HF). The incremental diagnostic value of tissue Doppler echocardiography, a reliable noninvasive estimate of LV filling pressures, has been reported in patients with preserved LV ejection fraction and discrepancy between BNP levels and the clinical judgment, however, its clinical validity in such patients in the presence of BNP concentrations in the midrange, which may reflect intermediate, nondiagnostic levels of LV filling pressures, is unknown. Methods: 34 patients without history of HF, presenting with acute dyspnea at rest, BNP levels of 100,400 pg/ml and normal LV ejection fraction were prospectively enrolled (17 with congestive HF and 17 with noncardiac cause). Tissue Doppler echocardiography was performed within 3 hours after admission. Results: unlike BNP (P = 0.78), Boston criteria (P = 0.0129), radiographic pulmonary edema (P = 0.0036) and average E/Ea ratio (P = 0.0032) were predictive of congestive HF by logistic regression analysis. In this clinical setting, radiographic pulmonary edema had a positive predictive value of 80% in the diagnosis of congestive HF. In patients without evidence of radiographic pulmonary edema, average E/Ea > 10 was a powerful predictor of congestive HF (area under the ROC curve of 0.886, P < 0.001, sensitivity 100% and specificity 78.6%). Conclusion: by better reflecting LV filling pressures, bedside tissue Doppler echocardiography accurately differentiates congestive HF from noncardiac cause in dyspneic patients with intermediate, nondiagnostic BNP levels and normal LV ejection fraction. [source]

    Visual Quantitative Estimation: Semiquantitative Wall Motion Scoring and Determination of Ejection Fraction

    ECHOCARDIOGRAPHY, Issue 5 2003
    M.D., Steven J. Lavine
    Ejection fraction (EF) is the most commonly used parameter of left ventricular (LV) systolic function and can be assessed by echocardiography. Quantitative echocardiography is time consuming and is as accurate as visual estimation, which has significant variability. We hypothesized that each echocardiographer has developed a mental set of guidelines that relate to how much individual segment shortening constitutes normal function or hypokinesis of varying extents. We determined the accuracy of applying these guidelines to an accepted technique of EF determination using a retrospective analysis of consecutive two-dimensional echocardiographic studies performed on patients who had radioventriculography (RVG) within 48 hours. Using a 12 segment model, we scored each segment at the base and mid-ventricular level based on segmental excursion and thickening. The apex was scored similarly but with 1/3 of the value based on a cylinder-cone model. EF was determined from the sum of segment scores and was estimated visually. We termed this approach visual quantitative estimation (VQE). We correlated the EF derived from VQE and visual estimation with RVG EF. In the training set, VQE demonstrated a strong correlation with RVG(r = 0.969), which was significantly greater than visual estimation(r = 0.896, P < 0.01). The limits of agreement for VQE (+12% to ,7%) were similar to the limits of RVG agreement with contrast ventriculography (+10% to ,11%) with similar intraobserver and interobserver variabilities. Similar correlation was noted in the prediction set between VQE and RVG EF(r = 0.967, P < 0.001). We conclude that VQE provides highly correlated estimates of EF with RVG. (ECHOCARDIOGRAPHY, Volume 20, July 2003) [source]

    A fully automated 2-D LC-MS method utilizing online continuous pH and RP gradients for global proteome analysis

    ELECTROPHORESIS, Issue 23 2007
    Hu Zhou
    Abstract The conventional 2-D LC-MS/MS setup for global proteome analysis was based on online and offline salt gradients (step and continuous) using strong-cation-exchange chromatography in conjunction with RP chromatography and MS. The use of the online system with step salt elution had the possibility of resulting in peptide overlapping across fractions. The offline mode had the option to operate with continuous salt gradient to decrease peak overlap, but exhibited decreased robustness, lower reproducibility, and sample loss during the process. Due to the extensive washing requirement between the chromatography steps, online continuous gradient was not an option for salt elution. In this report, a fully automated, online, and continuous gradient (pH continuous online gradient, pCOG) 2-D LC-MS/MS system is introduced that provided excellent separation and identification power. The pH gradient-based elution provided more basic peptides than that of salt-based elution. Fraction overlap was significantly minimized by combining pH and continuous gradient elutions. This latter approach also increased sequence coverage and the concomitant confidence level in protein identification. The salt and pH elution-based 2-D LC-MS/MS approaches were compared by analyzing the mouse liver proteome. [source]

    Body Dimensions of Infants Exposed to Antiepileptic Drugs In Utero: Observations Spanning 25 Years

    EPILEPSIA, Issue 7 2000
    K. Wide
    Summary: Purpose: To investigate the influence of maternal antiepileptic drug (AED) treatment on pregnancy duration, birth weight, body length, head circumference, and intrauterine growth in infants exposed in utero to antiepileptic drugs in Sweden between 1973,1997, with 963 singleton infants. Methods: Data collected from (a) 1973,1981 (record linkage between a hospital discharge register and a medical birth register); (b) 1984,1995 (prospectively collected information in one defined catchment area with two delivery hospitals); and (c) 1995,1997 (medical birth register data). Observed numbers of infants below a defined size for body measurements compared with expected numbers calculated from all births in Sweden after stratification for year of birth, maternal age, parity, and education or smoking habits in early pregnancy. Standard deviation scores estimated with same stratification procedures. Results: Fraction of monotherapy exposures increased from ,40% to ,90% from 1973 to 1997. Significantly increased numbers of infants with small body measurements found in exposed group. Negative influence on body dimensions decreased over time. More marked effects found in infants exposed to polytherapy. In monotherapy, only infants exposed to carbamazepine consistently showed reduction in body dimensions. Significant effect on gestational age in girls and on number of small for gestational age (<2 SD) in boys. Conclusions: Polytherapy with antiepileptic drugs and negative influence on body dimensions decreased. In monotherapy, only carbamazepine has a negative influence on body dimensions in this study. [source]

    Shade Effects on Phaseolus vulgaris L. Intercropped with Zea mays L. under Well-Watered Conditions

    M. Tsubo
    Abstract Field experiments were carried out under unstressed conditions of soil water during two summer crop growing seasons (1998,99 and 1999,2000 seasons) in a South African semi-arid region (Bloemfontein, Free State, South Africa). The aim of this study was to investigate shade effects on beans intercropped with maize in terms of plant mass and radiation use. The experimental treatments were two cropping systems (no shading/sole cropping and shading/intercropping) and two row orientations (north,south and east,west). At the top of bean canopies shaded by maize, incident radiation was reduced by up to 90 %. Shading reduced total dry matter of beans by 67 % at the end of the growing season, resulting in yield losses. The dry matter partitioning into leaf and stem (the ratios of leaf and stem to total biomass) was about 50 % higher in intercropping than sole cropping. In contrast, intercropped beans had 40 % lower dry matter partitioning into pod (the ratio of pod to total biomass). Fraction of radiation intercepted by sole-cropped beans steeply increased until canopy closure (0.9) and then slowly decreased, while fraction of radiation intercepted by intercropped beans remained constant between 0.0 and 0.2 throughout the growing seasons. However, intercropped beans had 77 % higher radiation use efficiency (RUE) than sole-cropped beans. In contrast, for maize, no effect of intercropping (shading) was found on growth, partitioning, yield, radiation interception or RUE. Consequently, lower bean yield losses can be attained in association with late shading rather than early shading. This can be controlled by growing crops with different temporal and spatial treatments. As regards row treatment, no effect of row direction was found on growth, partitioning, yield, radiation interception or RUE. [source]

    Mapping Quantitative Trait Loci for Vertebral Trabecular Bone Volume Fraction and Microarchitecture in Mice,

    Mary L Bouxsein
    Abstract BMD, which reflects both cortical and cancellous bone, has been shown to be highly heritable; however, little is known about the specific genetic factors regulating trabecular bone. Genome-wide linkage analysis of vertebral trabecular bone traits in 914 adult female mice from the F2 intercross of C57BL/6J and C3H/HeJ inbred strains revealed a pattern of genetic regulation derived from 13 autosomes, with 5,13 QTLs associated with each of the traits. Ultimately, identification of genes that regulate trabecular bone traits may yield important information regarding mechanisms that regulate mechanical integrity of the skeleton. Introduction: Both cortical and cancellous bone influence the mechanical integrity of the skeleton, with the relative contribution of each varying with skeletal site. Whereas areal BMD, which reflects both cortical and cancellous bone, has been shown to be highly heritable, little is known about the genetic determinants of trabecular bone density and architecture. Materials and Methods: To identify heritable determinants of vertebral trabecular bone traits, we evaluated the fifth lumbar vertebra from 914 adult female mice from the F2 intercross of C57BL/6J (B6) and C3H/HeJ (C3H) progenitor strains. High-resolution ,CT was used to assess total volume (TV), bone volume (BV), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), separation (Tb.Sp), and number (Tb.N) of the trabecular bone in the vertebral body in the progenitors (n = 8/strain) and female B6C3H-F2 progeny (n = 914). Genomic DNA from F2 progeny was screened for 118 PCR-based markers discriminating B6 and C3H alleles on all 19 autosomes. Results and Conclusions: Despite having a slightly larger trabecular bone compartment, C3H progenitors had dramatically lower vertebral trabecular BV/TV (,53%) and Tb.N (,40%) and higher Tb.Sp (71%) compared with B6 progenitors (p < 0.001 for all). Genome-wide quantitative trait analysis revealed a pattern of genetic regulation derived from 13 autosomes, with 5,13 quantitative trait loci (QTLs) associated with each of the vertebral trabecular bone traits, exhibiting adjusted LOD scores ranging from 3.1 to 14.4. The variance explained in the F2 population by each of the individual QTL after adjusting for contributions from other QTLs ranged from 0.8% to 5.9%. Taken together, the QTLs explained 22,33% of the variance of the vertebral traits in the F2 population. In conclusion, we observed a complex pattern of genetic regulation for vertebral trabecular bone volume fraction and microarchitecture using the F2 intercross of the C57BL/6J and C3H/HeJ inbred mouse strains and identified a number of QTLs, some of which are distinct from those that were previously identified for total femoral and vertebral BMD. Identification of genes that regulate trabecular bone traits may ultimately yield important information regarding the mechanisms that regulate the acquisition and maintenance of mechanical integrity of the skeleton. [source]

    Analysis of supersaturation and nucleation in a moving solution droplet with flowing supercritical carbon dioxide

    Mamata Mukhopadhyay
    Abstract A supercritical antisolvent (SAS) process is employed for production of solid nanoparticles from atomized droplets of dilute solution in a flowing supercritical carbon dioxide (SC CO2) stream by attaining extremely high, very rapid, and uniform supersaturation. This is facilitated by a two-way mass transfer of CO2 and solvent, to and from the droplet respectively, rendering rapid reduction in equilibrium solubility of the solid solute in the ternary solution. The present work analyses the degree of supersaturation and nucleation kinetics in a single droplet of cholesterol solution in acetone during its flight in a flowing SC CO2 stream. Both temperature and composition are assumed to be uniform within the droplet, and their variations with time are calculated by balancing the heat and mass transfer fluxes to and from the droplet. The equilibrium solubility of cholesterol with CO2 dissolution has been predicted as being directly proportional to the Partial Molar Volume Fraction (PMVF) of acetone in the binary (CO2,acetone) system. The degree of supersaturation has been simulated up to the time required to attain almost zero cholesterol solubility in the droplet for evaluating the rate of nucleation and the size of the stable critical nuclei formed. The effects of process parameters have been analysed in the pressure range of 7.1,35.0 MPa, temperature range of 313,333 K, SC CO2 flow rate of 0.1136,1.136 mol s,1, the ratio of the volumetric flow rates of CO2 -to-solution in the range of 100,1000, and the initial mole fraction of cholesterol in acetone solution in the range of 0.0025,0.010. The results confirm an extremely high and rapid increase in degree of supersaturation, very high nucleation rates and stable critical nucleus diameter of the order of a nanometre. Copyright © 2005 Society of Chemical Industry [source]

    Antioxidant Activity of Crude Extract, Alkaloid Fraction, and Flavonoid Fraction from Boldo (Peumus boldus Molina) Leaves

    N. Quezada
    ABSTRACT: Boldo is an endemic plant from Chile widely used in folk medicine, whose biological (mainly antioxidant) activity has been attributed to the presence of the alkaloid boldine. The aim of this study was to determine the contribution of the flavonoid and other crude fractions from boldo leaves to the antioxidant activity of extracts. The main constituent in the flavonoid fraction was also isolated. The antioxidant activity and reducing power of crude boldo extract and fractions were measured and compared with natural and synthetic antioxidants. The antioxidant activity of boldo leaf extracts came mainly from the flavonoid fraction (44.1%) followed by the alkaloid fraction (15.6%), with catechin and boldine being the main contributors of the antioxidant activity of these 2 fractions (60.9% and 35.6% of the total activity, respectively). On the basis of these results, we propose to use catechin and boldine as markers for the antioxidant activity of boldo leaves. Tailor-made antioxidants to be used in foods can be prepared by enriching these 2 fractions. [source]

    Influence of Blanching-osmotic Dehydration Treatments on Volatile Fraction of Strawberries

    I. Escriche
    ABSTRACT: The effects of steam (S) and microwave (MW) blanching and osmotic treatments, applied either singularly or combined, on the volatile fraction of strawberry have been evaluated. Osmotic dehydration was carried out at atmospheric conditions (OD) and by applying a vacuum pulse at the beginning of the process (PVOD). Volatiles were obtained by a simultaneous distillation-extraction procedure and identified/quantified by gas chromatography-mass spectrometry. Esters and 2,5-dimethyl-4-hydroxy-3(2H)-furanone were the major compounds. Differences in volatile concentration promoted by blanching and/or osmotic processes were evaluated. Osmotic treatments promote formation of esters and furanones, differently for either OD or PVOD treatments, but this effect was greatly inhibited when osmosis was preceded by blanching. The kind of blanching (MW or S) also affected the sample final volatile profile. [source]

    Impact of cerebrospinal fluid contamination on brain metabolites evaluation with 1H-MR spectroscopy: A single voxel study of the cerebellar vermis in patients with degenerative ataxias

    Laura Guerrini MD PhD
    Abstract Purpose To investigate the impact of cerebrospinal fluid (CSF) contamination on metabolite evaluation in the superior cerebellar vermis with single-voxel 1H-MRS in normal subjects and patients with degenerative ataxias. Materials and Methods Twenty-nine healthy volunteers and 38 patients with degenerative ataxias and cerebellar atrophy were examined on a 1.5 Tesla scanner. Proton spectra of a volume of interest placed in the superior vermis were acquired using a four TE PRESS technique. We calculated N-acetyl aspartate (NAA)/creatine (Cr), choline (Cho)/Cr, and NAA/Cho ratios, T2 relaxation times and concentrations of the same metabolites using the external phantom method. Finally, concentrations were corrected taking into account the proportion of nervous tissue and CSF, that was determined as Volume Fraction (VF). Results In healthy subjects, a significant difference was observed between metabolite concentrations with and without correction for VF. As compared to controls, patients with ataxias showed significantly reduced NAA/Cr and NAA concentrations, while only corrected Cr concentration was significantly increased. The latter showed an inverse correlation with VF. Conclusion CSF contamination has a not negligible effect on the estimation of brain metabolites. The increase of Cr concentration in patients with cerebellar atrophy presumably reflects the substitutive gliosis which takes place along with loss of neurons. J. Magn. Reson. Imaging 2009;30:11,17. © 2009 Wiley-Liss, Inc. [source]

    Cranberry proanthocyanidins associate with low-density lipoprotein and inhibit in vitro Cu2+ -induced oxidation,

    Mandy L Porter
    Abstract Antioxidant activity of six fractions of cranberry phenolic compounds was determined by inhibition of Cu2+ -induced low-density lipoprotein (LDL) oxidation. The phenolic composition of each fraction was determined by high-performance liquid chromatography. The phenolic fractions were mixed with aliquots of modified human serum prior to LDL isolation. The serum was modified to remove very-low-density lipoprotein and chylomicrons that may bind phenolic compounds. Only fractions 5 and 6 that contained proanthocyanidins (PAs) significantly increased the lag time of LDL oxidation, and the lag time for fraction 6 was significantly higher than for fraction 5. The mass distribution of PAs in these fractions was obtained by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, a technique that allows rapid characterisation of the molecular weight distribution in mixtures of oligomeric compounds. Fraction 5 contained trimers through heptamers, whereas fraction 6 contained pentamers through nonamers. In addition, fraction 6 contained PA oligomers with more doubly linked, A-type interflavan bonds. Results indicate that PAs specifically associate with LDL in modified serum and increase the lag time of Cu2+ -induced oxidation. Differences between fractions 5 and 6 in PA structure and effects on LDL oxidation suggest that the degree of polymerisation and the nature of the interflavan bond influence antioxidant properties. © 2001 Society of Chemical Industry [source]

    Thickening Processes of Lamellar Crystal Monolayers of a Low-Molecular-Weight PEO Fraction on a Solid Surface

    Xuemei Zhai
    Abstract Using hot-stage atomic force microscopy, the thickening processes of monolayer crystals of PEO (,=,5,000 g,·,mol,1 and ,=,1.008) from one-folded (FC1) to extended-chain (EC) lamellae are experimentally monitored at three temperatures: 50, 52, and 58,°C. At 50,°C some small areas in large FC1 crystals spontaneously thicken into EC crystals. At 52,°C the spontaneously thickened area further expands so as to inductively thicken the entire FC1 lamella into EC lamella. At 58,°C EC crystals first force the adjacent FC1 crystals to melt and then absorb the melted molecules to grow laterally into large EC lamellae till all FC1 lamellae vanish. The three thickening steps express the main thickening process of lamellar crystals from a metastable state to another metastable (or equilibrium) state. The possible mechanisms are discussed in the text. [source]

    Passive smoking is a major determinant of exhaled nitric oxide levels in allergic asthmatic children

    ALLERGY, Issue 4 2010
    Y. Laoudi
    To cite this article: Laoudi Y, Nikasinovic L, Sahraoui F, Grimfeld A, Momas I, Just J. Passive smoking is a major determinant of exhaled nitric oxide levels in allergic asthmatic children. Allergy 2010; 65: 491,497. Abstract Background:, Fraction of exhaled nitric oxide (FeNO) is considered, by some authors, to be a treatment follow-up parameter in allergic asthmatics. However, factors such as active smoking can influence NO production and must be taken into account in the interpretation of FeNO values. In children, the evidence in favour of an impact of passive smoking (PS) on FeNO values is controversial. The aim of this study was to evaluate the impact of chronic PS on FeNO in allergic asthmatic children. Methods:, Seventy nontreated allergic asthmatic children over 5 years of age, exposed and unexposed to PS, underwent measurement of FeNO, spirometry, and allergic tests (skin prick tests, total and specific serum IgE, and blood eosinophilia). Children were considered to be exposed to PS when at least 1 cigarette per day was declared to be smoked at home. Results:, Geometric mean FeNO value in 22 children exposed to PS was 26.3 ± 1.5 ppb vs 56.3 ± 1.7 ppb in 48 children unexposed (P < 0.001). After adjustment for age, blood eosinophilia, allergic sensitizations, total IgE, dust mite sensitization and asthma severity, multivariate analysis showed that PS exposure was negatively associated with FeNO values (P = 0.0001) and was the primary determinant of FeNO variations. Conclusion:, Passive smoking lowers FeNO, and might be a major determinant of FeNO levels in nontreated allergic asthmatic children. [source]

    Autologous Whole Ram Seminal Plasma and its Vesicle-free Fraction Improve Motility Characteristics and Membrane Status but not In Vivo Fertility of Frozen,Thawed Ram Spermatozoa

    R El-Hajj Ghaoui
    Contents Motility characteristics (assessed subjectively and with computer-assisted semen analysis) and membrane status (after staining with chlortetracycline) of washed and non-washed frozen,thawed ram spermatozoa were evaluated after incubation in buffer and buffer containing autologous whole seminal plasma or one of its two fractions: the pellet of membrane vesicles obtained by ultracentrifugation (and used at three times normal protein concentration) or the vesicle-free supernatant fraction. Whole seminal plasma and supernatant, but not membrane vesicles, improved the motility characteristics of spermatozoa after 3 and 6 h of post-thaw incubation compared with the control buffer. Resuspension and incubation with whole seminal plasma, supernatant or membrane vesicles lowered the proportion of acrosome-reacted frozen,thawed spermatozoa compared with the control buffer. Unwashed frozen,thawed semen from three rams, incubated with autologous whole seminal plasma or its fractions and inseminated using cervical or intrauterine artificial insemination, had no effect on pregnancy rates of ewes in synchronized oestrus. However, fertility was higher after laparoscopic than cervical insemination (44.9 vs 12.3%, p < 0.001). In conclusion, resuspension and incubation of frozen,thawed ram spermatozoa in autologous whole seminal plasma or its vesicle-free supernatant fraction improved their motility characteristics and, with membrane vesicles, membrane status, but these benefits were not reflected in improved fertility after cervical or intrauterine insemination. [source]

    Exercise-induced wheeze: Fraction of exhaled nitric oxide-directed management

    RESPIROLOGY, Issue 4 2010
    Douglas C. COWAN
    ABSTRACT Background and objective: Exercise-induced wheeze (EIW) is common. Several treatment options exist. Patients with low fraction of exhaled nitric oxide (FENO) are unlikely to be steroid-responsive and might benefit from non-steroidal therapies. We assessed: the efficacy of cromoglycate, formoterol and montelukast in patients with EIW and low FENO (<35 ppb) in a randomized cross-over trial, and the efficacy of inhaled corticosteroid in a high FENO (>35 ppb) group. Methods: Patients had EIW and airway hyperresponsiveness (AHR) to mannitol and/or exercise. Those with low FENO (n = 19) received cromoglycate (20 mg inh. bd + before challenge tests), formoterol (12 µg inh. bd + before challenge tests) and montelukast (10 mg p.o. od), each for 2 weeks. Those with high FENO (n = 20) took inhaled fluticasone (500 µg) daily for 4 weeks. Primary end-points were: 50% reduction in maximum FEV1 %fall (clinical protection) and decrease in AHR to mannitol. Results: In patients with low FENO, cromoglycate, formoterol and montelukast significantly decreased AHR to mannitol in 63%, 61% and 47% of patients, respectively. In this group, the magnitude of exercise-induced bronchoconstriction (EIB) was significantly reduced with montelukast and formoterol; between-treatment differences were not significant. Of 6/19 with low FENO and EIB, protection occurred in 67% (cromoglycate), 83% (formoterol) and 50% (montelukast), respectively. In the high FENO group, AHR to mannitol and EIB decreased significantly with fluticasone (P < 0.001, P = 0.005, respectively), and protection occurred in 7/8 (88%) with EIB. Conclusions: In patients with EIW and low FENO, the number of ,responders' to cromoglycate, formoterol and montelukast was similar. In a high FENO population the response to inhaled corticosteroid was highly significant and comparable to previous studies. [source]

    What Fraction of a Capital Investment is Sunk Costs?

    Marcus Asplund
    To what extent are capital investments sunk costs? This question is addressed by examining the salvage values of discarded metalworking machinery. Even though such assets are expected to be non-specific, many discarded assets are scrapped rather than sold on second-hand markets. Econometric results suggest that firms can only expect to get back 20,50 percent of the initial price of a ,new' machine once it is installed. The results also indicate differences in value-age profiles across firms, but provide only weak support for the hypothesis that salvage values are particularly low during recessions. [source]

    Intertwined Refractions: The Mutual Constitution of Gender Style and Class Fraction in a De-Industrializing Australian Town

    Allon J. Uhlmann
    Based on fieldwork among urban working-class Australians, I divide the dominated class into two fractions, dominated and dominant, and use this as a basis for analysis of the multiple gender styles which have been observed in working-class Australia. I argue that masculine style and class-fraction location are mutually constitutive. I also explain why feminine style is not as diverse as masculine style, nor is the location of women within working-class fractions as definite as that of men. Finally, I suggest that not only within the working class, but also between classes, gender style and class location are mutually constitutive. [source]