5,019 research outputs found

    Cooking quality, digestibility, and sensory properties of proso millet pasta as impacted by amylose content and prolamin profile

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    As part of ongoing e\ufb00orts to promote millet as a double crop for the American Midwest, four Minnesota-grownproso millet varieties were selected for fresh gluten-free pasta production and compared to commerciallyavailable fresh gluten-free and wheat pasta. Raw and cooked pasta were analyzed for starch and protein content,color, and carotenoids. Cooked pasta was assessed for cooking quality, in-vitro starch and protein digestibility,and sensory quality. Millet pasta contained less rapidly digestible starch than commercial gluten-free pasta;however, millet and commercial gluten-free pasta had lower protein digestibility than wheat pasta. Sensorypanelists detected more graininess and starchiness in millet samples than in commercial pasta. Millet varietiesdi\ufb00ered in amylose content and prolamin pro\ufb01le, and both factors in\ufb02uenced pasta properties. Pasta with moreamylose and high-molecular weight prolamins had lower cooking loss and lower stickiness scores. Higheramylose contents also corresponded to higher \ufb01rmness and chewiness among millet pasta samples. The milletsample with the lowest amylose and prolamin content yielded pasta of the lowest quality. Results indicated thatselect proso millet varieties may be suitable for fresh pasta, yet quality improvement is warranted by recipe orprocessing optimizations

    Transverse stability of relativistic two-component jets

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    Context: Astrophysical jets from various sources seem to be stratified, with a fast inner jet and a slower outer jet. As it is likely that the launching mechanism for each component is different, their interface will develop differential rotation, while the outer jet radius represents a second interface where disruptions may occur. Aims: We explore the stability of stratified, rotating, relativistic two-component jets, in turn embedded in static interstellar medium. Methods: In a grid-adaptive relativistic hydrodynamic simulation with the AMRVAC code, the non-linear azimuthal stability of two-component relativistic jets is investigated. We simulate until multiple inner jet rotations have been completed. Results: We find evidence for the development of an extended shear flow layer between the two jet components, resulting from the growth of a body mode in the inner jet, Kelvin-Helmholtz surface modes at their original interface, and their nonlinear interaction. Both wave modes are excited by acoustic waves which are reflected between the symmetry axis and the interface of the two jet components. Their interaction induces the growth of near stationary, counterrotating vortices at the outer edge of the shear flow layer. The presence of a heavy external jet allows to slow down their further development, and maintain a collimated flow. At the outer jet boundary, small-scale Rayleigh-Taylor instabilities develop, without disrupting the jet configuration. Conclusion: We demonstrate that the cross-section of two-component relativistic jets, with a heavy, cold outer jet, is non-linearly stable.Comment: Accepted in A&A 24/09/200

    Very High Mach Number Electrostatic Shocks in Collisionless Plasmas

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    The kinetic theory of collisionless electrostatic shocks resulting from the collision of plasma slabs with different temperatures and densities is presented. The theoretical results are confirmed by self-consistent particle-in-cell simulations, revealing the formation and stable propagation of electrostatic shocks with very high Mach numbers (M10M \gg 10), well above the predictions of the classical theories for electrostatic shocks.Comment: 6 pages, submitted to Phys. Rev. Let

    Gonadotrophin stimulation for in vitro fertilization significantly alters the hormone milieu in follicular fluid: a comparative study between natural cycle IVF and conventional IVF

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    STUDY QUESTION Is the steroid hormone profile in follicular fluid (FF) at the time of oocyte retrieval different in naturally matured follicles, as in natural cycle IVF (NC-IVF), compared with follicles stimulated with conventional gonadotrophin stimulated IVF (cIVF)? SUMMARY ANSWER Anti-Mullerian hormone (AMH), testosterone (T) and estradiol (E2) concentrations are ∼3-fold higher, androstenedione (A2) is ∼1.5-fold higher and luteinizing hormone (LH) is ∼14-fold higher in NC-IVF than in cIVF follicles, suggesting an alteration of the follicular metabolism in conventional gonadotrophin stimulated IVF. WHAT IS KNOWN ALREADY In conventional IVF, the implantation rate of unselected embryos appears to be lower than in NC-IVF, which is possibly due to negative effects of the stimulation regimen on follicular metabolism. In NC-IVF, the intrafollicular concentration of AMH has been shown to be positively correlated with the oocyte fertilization and implantation rates. Furthermore, androgen treatment seems to improve the ovarian response in low responders. STUDY DESIGN, SIZE, DURATION This cross-sectional study involving 36 NC-IVF and 40 cIVF cycles was performed from 2011 to 2013. Within this population, 13 women each underwent 1 NC-IVF and 1 cIVF cycle. cIVF was performed by controlled ovarian stimulation with HMG and GnRH antagonists. PARTICIPANTS/MATERIALS, SETTING, METHODS Follicular fluid was collected from the leading follicles. AMH, T, A2, dehydroepiandrosterone (DHEA), E2, FSH, LH and progesterone (P) were determined by immunoassays in 76 women. Aromatase activity in follicular fluid cells was analysed by a tritiated water release assay in 33 different women. For statistical analysis, the non-parametric Mann-Whitney U or Wilcoxon tests were used. MAIN RESULTS AND ROLE OF CHANCE In follicular fluid from NC-IVF and from cIVF, median levels were 32.8 and 10.7 pmol/l for AMH (P < 0.0001), 47.2 and 18.8 µmol/l for T (P < 0.0001), 290 and 206 nmol/l for A2 (P = 0.0035), 6.7 and 5.6 pg/ml for DHEA (n.s.), 3292 and 1225 nmol/l for E2 (P < 0.0001), 4.9 and 7.2 mU/ml for FSH (P < 0.05), 14.4 and 0.9 mU/ml for LH (P < 0.0001) and 62 940 and 54 710 nmol/l for P (n.s.), respectively. Significant differences in follicular fluid concentrations for AMH, E2 and LH were also found in the 13 patients who underwent both NC-IVF and cIVF when they were analysed separately in pairs. Hormone analysis in serum excluded any relevant impact of AMH, T, A2, and E2 serum concentration on the follicular fluid hormone concentrations. Median serum concentrations were 29.4 and 0.9 mU/ml for LH (P < 0.0001) and 2.7 and 23.5 nmol/l for P (P < 0.0001) after NC-IVF and c-IVF, respectively. Positive correlations were seen for FF-AMH with FF-T (r = 0.35, P = 0.0002), FF-T with FF-LH (r = 0.48, P < 0.0001) and FF-E2 with FF-T (r = 0.75, P < 0.0001). The analysis of aromatase activity was not different in NC-IVF and cIVF follicular cells. LIMITATION, REASONS FOR CAUTION Any association between the hormone concentrations and the implantation potential of the oocytes could not be investigated as the oocytes in cIVF were not treated individually in the IVF laboratory. Since both c-IVF and NC-IVF follicles were stimulated by hCG before retrieval, the endocrine milieu in the natural cycle does not represent the pure physiological situation. WIDER IMPLICATIONS OF THE FINDINGS The endocrine follicular milieu and the concentration of putative markers of oocyte quality, such as AMH, are significantly different in gonadotrophin-stimulated conventional IVF compared with natural cycle IVF. This could be a cause for the suggested lower oocyte quality in cIVF compared with naturally matured oocytes. The reasons for the reduced AMH concentration might be low serum and follicular fluid LH concentrations due to LH suppression, leading initially to low follicular androgen concentrations and then to low follicular AMH production. STUDY FUNDING/COMPETING INTERESTS Funding for this study was obtained from public universities (for salaries) and private industry (for consumables). Additionally, the study was supported by an unrestricted grant from MSD Merck Sharp & Dohme GmbH and IBSA Institut Biochimique SA. The authors are clinically involved in low-dose monofollicular stimulation and IVF therapies, using gonadotrophins from all gonadotrophin distributors on the Swiss market, including Institut Biochimique SA and MSD Merck Sharp & Dohme GmbH. Otherwise, the authors have no competing interests. TRIAL REGISTRATION NUMBER Not applicabl

    Common molecular pathways involved in human CD133+/CD34+ progenitor cell expansion and cancer

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    <p>Abstract</p> <p>Background</p> <p>Uncovering the molecular mechanism underlying expansion of hematopoietic stem and progenitor cells is critical to extend current therapeutic applications and to understand how its deregulation relates to leukemia. The characterization of genes commonly relevant to stem/progenitor cell expansion and tumor development should facilitate the identification of novel therapeutic targets in cancer.</p> <p>Methods</p> <p>CD34+/CD133+ progenitor cells were purified from human umbilical cord blood and expanded <it>in vitro</it>. Correlated molecular changes were analyzed by gene expression profiling using microarrays covering up to 55,000 transcripts. Genes regulated during progenitor cell expansion were identified and functionally classified. Aberrant expression of such genes in cancer was indicated by <it>in silico </it>SAGE. Differential expression of selected genes was assessed by real-time PCR in hematopoietic cells from chronic myeloid leukemia patients and healthy individuals.</p> <p>Results</p> <p>Several genes and signaling pathways not previously associated with <it>ex vivo </it>expansion of CD133+/CD34+ cells were identified, most of which associated with cancer. Regulation of MEK/ERK and Hedgehog signaling genes in addition to numerous proto-oncogenes was detected during conditions of enhanced progenitor cell expansion. Quantitative real-time PCR analysis confirmed down-regulation of several newly described cancer-associated genes in CD133+/CD34+ cells, including <it>DOCK4 </it>and <it>SPARCL1 </it>tumor suppressors, and parallel results were verified when comparing their expression in cells from chronic myeloid leukemia patients</p> <p>Conclusion</p> <p>Our findings reveal potential molecular targets for oncogenic transformation in CD133+/CD34+ cells and strengthen the link between deregulation of stem/progenitor cell expansion and the malignant process.</p
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