259 research outputs found

    Quality assessments of untreated and washed quinoa (Chenopodium quinoa) seeds based on histlogical and foaming capacity investigations

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    Quinoa seed has a high nutritional value, but has a coating of bitter-tasting saponins, making it unpalatable. Therefore the seeds are usually processed in order to remove the naturally occurring saponins from the seeds. To investigate the impact of processing, untreated and washed seeds of the white and brown types of quinoa were investigated histologically and by foaming capacity evaluations. Reference samples of known origin and treatment were investigated as well as unknown samples. The results revealed a relationship between the presence of saponin containing papillose cells at the outermost layer of the seed hull in the histological sections and the foaming capacity of the seeds. After washing, the papillose cells were severely damaged or completely removed and virtually no foam formation was observed. This investigation indicatedthat washing resulted in an effective removal of the saponin layer, leading to quality improvement of the seeds intended for human and animal consumption. The same features were observed for the unknown samples. These results imply that the treatment of the investigated samples was based on washing. The determination of the type of treatment applied provided useful information for the correct tax classification for Custom purposes

    Anisotropic Colossal Magnetoresistance Effects in Fe_{1-x}Cu_xCr_2S_4

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    A detailed study of the electronic transport and magnetic properties of Fe1x_{1-x}Cux_xCr2_2S4_4 (x0.5x \leq 0.5) on single crystals is presented. The resistivity is investigated for 2T3002 \leq T \leq 300 K in magnetic fields up to 14 Tesla and under hydrostatic pressure up to 16 kbar. In addition magnetization and ferromagnetic resonance (FMR) measurements were performed. FMR and magnetization data reveal a pronounced magnetic anisotropy, which develops below the Curie temperature, TCT_{\mathrm{C}}, and increases strongly towards lower temperatures. Increasing the Cu concentration reduces this effect. At temperatures below 35 K the magnetoresistance, MR=ρ(0)ρ(H)ρ(0)MR = \frac{\rho(0) - \rho(H)}{\rho(0)}, exhibits a strong dependence on the direction of the magnetic field, probably due to an enhanced anisotropy. Applying the field along the hard axis leads to a change of sign and a strong increase of the absolute value of the magnetoresistance. On the other hand the magnetoresistance remains positive down to lower temperatures, exhibiting a smeared out maximum with the magnetic field applied along the easy axis. The results are discussed in the ionic picture using a triple-exchange model for electron hopping as well as a half-metal utilizing a band picture.Comment: some typos correcte

    Half-metallic antiferromagnets in thiospinels

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    We have theoretically designed the half-metallic (HM) antiferromagnets (AFMs) in thiospinel systems, Mn(CrV)S4\rm Mn(CrV)S_{4} and Fe0.5Cu0.5(V0.5Ti1.5)S4\rm Fe_{0.5}Cu_{0.5}(V_{0.5}Ti_{1.5})S_{4}, based on the electronic structure studies in the local-spin-density approximation (LSDA). We have also explored electronic and magnetic properties of parent spinel compounds of the above systems; CuV2S4\rm CuV_{2}S_{4} and CuTi2S4\rm CuTi_{2}S_{4} are found to be HM ferromagnets in their cubic spinel structures, while MnCr2S4\rm MnCr_{2}S_{4} is a ferrimagnetic insulator. We have discussed the feasibility of material synthesis of HM-AFM thiospinel systems.Comment: 4 pages, 5 figure

    First-principles study of the inversion thermodynamics and electronic structure of FeM2X4 (thio)spinels (M = Cr, Mn, Co, Ni; X = O, S)

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    FeM2X4 spinels, where M is a transition metal and X is oxygen or sulfur, are candidate materials for spin filters, one of the key devices in spintronics. We present here a computational study of the inversion thermodynamics and the electronic structure of these (thio)spinels for M = Cr, Mn, Co, Ni, using calculations based on the density functional theory with on-site Hubbard corrections (DFT+U). The analysis of the configurational free energies shows that different behaviour is expected for the equilibrium cation distributions in these structures: FeCr2X4 and FeMn2S4 are fully normal, FeNi2X4 and FeCo2S4 are intermediate, and FeCo2O4 and FeMn2O4 are fully inverted. We have analyzed the role played by the size of the ions and by the crystal field stabilization effects in determining the equilibrium inversion degree. We also discuss how the electronic and magnetic structure of these spinels is modified by the degree of inversion, assuming that this could be varied from the equilibrium value. We have obtained electronic densities of states for the completely normal and completely inverse cation distribution of each compound. FeCr2X4, FeMn2X4, FeCo2O4 and FeNi2O4 are half-metals in the ferrimagnetic state when Fe is in tetrahedral positions. When M is filling the tetrahedral positions, the Cr-containing compounds and FeMn2O4 are half-metallic systems, while the Co and Ni spinels are insulators. The Co and Ni sulfide counterparts are metallic for any inversion degree together with the inverse FeMn2S4. Our calculations suggest that the spin filtering properties of the FeM2X4 (thio)spinels could be modified via the control of the cation distribution through variations in the synthesis conditions

    Thermodynamics of Nonstoichiometric Nickel Tellurides. I. Heat Capacity and Thermodynamic Functions of the δ Phase from 5 to 350°K

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    Heat capacities of the nickel tellurides were measured at compositions NiTe1.1 and NiTe2.0 (near limits of homogeneity of the δ phase) and at one intermediate composition, NiTe1.5, from 5 to 350°K. Heat capacity values and entropy and enthalpy increments are tabulated. No evidence of order‐disorder transitions, or thermal anomalies, or of contributions to the thermal properties from the anisotropy or phonon scattering by the holes in the structure on approaching the composition NiTe2 was observed. Although simple additivity of the heat capacities of the constituent elements failed to represent that of the solution compositions adequately, a Kopp‐Neumann treatment in terms of the limiting compositions of the δ phase gives good agreement with the experimental heat capacity and entropy of NiTe1.5 and hence is useful in interpolating to other intermediate compositions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70090/2/JCPSA6-28-3-497-1.pd

    Haemorrhagia post partum; an implementation study on the evidence-based guideline of the Dutch Society of Obstetrics and Gynaecology (NVOG) and the MOET (Managing Obstetric Emergencies and Trauma-course) instructions; the Fluxim study

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    Contains fulltext : 88435.pdf (publisher's version ) (Open Access)BACKGROUND: One of the most important causes of maternal mortality and severe morbidity worldwide is post partum haemorrhage (PPH). Factors as substandard care are frequently reported in the international literature and there are similar reports in the Netherlands. The incidence of PPH in the Dutch population is 5% containing 10.000 women a year. The introduction of an evidence-based guideline on PPH by the Dutch society of Obstetrics and Gynaecology (NVOG) and the initiation of the MOET course (Managing Obstetrics Emergencies and Trauma) did not lead to a reduction of PPH. This implies the possibility of an incomplete implementation of both the NVOG guideline and MOET-instructions. Therefore, the aim of this study is to develop and test a tailored strategy to implement both the NVOG guideline and MOET-instructions METHODS/DESIGN: One step in the development procedure is to evaluate the implementation of the guideline and MOET-instructions in the current care. Therefore measurement of the actual care will be performed in a representative sample of 20 hospitals. This will be done by prospective observation of the third stage of labour of 320 women with a high risk of PPH using quality indicators extracted from the NVOG guideline and MOET instructions. In the next step barriers and facilitators for guideline adherence will be analyzed by performance of semi structured interviews with 30 professionals and 10 patients, followed by a questionnaire study among all Dutch gynaecologists and midwives to quantify the barriers mentioned. Based on the outcomes, a tailored strategy to implement the NVOG guideline and MOET-instructions will be developed and tested in a feasibility study in 4 hospitals, including effect-, process- and cost evaluation. DISCUSSION: This study will provide insight into current Dutch practice, in particular to what extent the PPH guidelines of the NVOG and the MOET-instructions have been implemented in the actual care, and into the barriers and facilitators regarding guideline adherence. The knowledge of the feasibility study regarding the effects and costs of the tailored strategy and the experiences of the users can be used in countries with a relatively high incidence of PPH. TRIAL REGISTRATION: ClinicTrials.gov NCT00928863

    Effect of childbirth on the course of Crohn's disease; results from a retrospective cohort study in the Netherlands

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    Contains fulltext : 95846.pdf (publisher's version ) (Open Access)BACKGROUND: Pregnant women with Crohn's disease needs proper counselling about the effect of pregnancy and childbirth on their disease. However, Literature about the effect of childbirth on Crohn's disease is limited. This study examined the effect of childbirth on the course of Crohn's disease and especially perianal Crohn's disease. METHODS: This is a retrospective cohort study which was performed in a tertiary level referral hospital in the Netherlands. From the IBD database, female patients aged 18-80 years in 2004 were selected. Data analysis took place in the years 2005 and 2006. Eventually, 114 women with at least one pregnancy after the diagnosis of Crohn's disease were eligible for the study. Differences between groups were analyzed using Wilcoxon Mann Whitney tests and Chi-square analysis with 2 x 2 or 2 x 3 contingency tables. Two-tailed values were used and p values < 0.05 were considered statistically significant. RESULTS: 21/114 women (18%) had active luminal disease prior to pregnancy, with significantly more pregnancy related complications compared to women with inactive luminal disease (Odds ratio 2.8; 95% CI 1.0 - 7.4). Caesarean section rate was relatively high (37/114, 32%), especially in patients with perianal disease prior to pregnancy compared to women without perianal disease (Odds ratio 4.6; 95% CI 1.8 - 11.4). Disease progression after childbirth was more frequent in patients with active luminal disease prior to pregnancy compared to inactive luminal disease (Odds ratio 9.7; 95% CI 2.1 - 44.3). Progression of perianal disease seems less frequent after vaginal delivery compared with caesarean section, in both women with prior perianal disease (18% vs. 31%, NS) and without prior perianal disease (5% vs 14%, NS). There were no more fistula-related complications after childbirth in women with an episiotomy or second degree tear. CONCLUSION: A relatively high rate of caesarean sections was observed in women with Crohn's disease, especially in women with perianal disease prior to pregnancy. A protective effect of caesarean section on progression of perianal disease was not observed. However, this must be interpreted carefully due to confounder effect by indication for caesarean section

    Pregnancy related back pain, is it related to aerobic fitness? A longitudinal cohort study

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    <p>Abstract</p> <p>Background</p> <p>Low back pain with onset during pregnancy is common and approximately one out of three women have disabling pain. The pathogenesis of the pain condition is uncertain and there is no information on the role of physical fitness. Whether poorer physical conditioning is a cause or effect of back pain is also disputed and information from prospective studies needed.</p> <p>Methods</p> <p>A cohort of pregnant women, recruited from maternal health care centers in central Sweden, were examined regarding estimated peak oxygen uptake by cycle ergometer test in early pregnancy, reported physical activity prior to pregnancy, basic characteristics, back pain during pregnancy and back pain postpartum.</p> <p>Results</p> <p>Back pain during the current pregnancy was reported by nearly 80% of the women. At the postpartum appointment this prevalence was 40%. No association was displayed between estimated peak oxygen uptake and incidence of back pain during and after pregnancy, adjusted for physical activity, back pain before present pregnancy, previous deliveries, age and weight. A significant inverse association was found between estimated peak oxygen uptake and back pain intensity during pregnancy and a direct association post partum, in a fully adjusted multiple linear regression analysis.</p> <p>Conclusions</p> <p>Estimated peak oxygen uptake and reported physical activity in early pregnancy displayed no influence on the onset of subsequent back pain during or after pregnancy, where the time sequence support the hypothesis that poorer physical deconditioning is not a cause but a consequence of the back pain condition. The mechanism for the attenuating effect of increased oxygen uptake on back pain intensity is uncertain.</p
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