378 research outputs found

    Zusammenhänge zwischen Kalttestwert, Anbauverfahren und Ertragsbildung bei Vermehrungssaatgut von Winterroggen [Correlation between "coldtest" value, production method and yield in winter rye seeds for multiplication]

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    Proben von zertifiziertem Saatgut aus ökologischem Anbau werden bei 10°C einer speziellen Keimprobe (Kalttest) unterzogen, um bodenbürtige Krankheiten festzustellen. Proben mit einem Anteil von mehr als 80% gesunder Pflanzen (Kalttestwert) können als Saatgut verwendet werden. Proben unter 80% müssen als Nahrungs- oder Futtermittel verwendet werden. In einem Feldversuch wurden Proben mit Kalttestwerten unter 80% mit Proben der gleichen Sorte verglichen, deren Kalttestwert mindestens 80% betrug. Unter normalen Anbaubedingungen bestand kein Ertragsunterschied zwischen den Proben bis zu einem Wert von 60%. Unter Stresseinfluss (Getreide als Vorfrucht, späte Aussaat) bewirkten bereits wenig abgesenkte Kalttestwerte signifikante Ertragsverluste. Um gute Qualität von zertifiziertem Saatgut zu gewährleisten, sollte der Kalttestwert bei 80% bleiben

    Magnetism of the LTT phase of Eu doped La_{2-x}Sr_xCuO_4

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    The ESR signal of Gd spin probes (0.5 at %) as well as the static normal state susceptibility of Eu (J(Eu^{3+})=0) doped La_{2-x-y}Sr_xEu_yCuO_4 reveal pronounced changes of the Cu magnetism at the structural transition from the orthorhombic to the low temperature tetragonal phase for all non-superconducting compositions. Both a jumplike decrease of \chi as well as the ESR data show an increase of the in-plane magnetic correlation length in the LTT phase. From the Gd^{3+} ESR linewidth we find that for specific Eu and Sr concentrations in the LTT phase the correlation length increases up to more than 100 lattice constants and the fluctuation frequency of the CuO_2 spin system slows down to 10^{10}- 10^{11}sec^{-1}. However, there is no static order above T ~ 8K in contrast to the LTT phase of Nd doped La_{2-x}Sr_xCuO_4 with pinned stripe correlations.Comment: 7 pages, RevTex, 3 eps figures. To appear in the Proceedings of the International Conference "Stripes, Lattice Instabilities and High Tc Superconductivity", (Rome, Dec. 1996

    Dzyaloshinsky-Moriya Spin Canting in the LTT Phase of La2-x-yEuySrxCuO4

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    The Cu spin magnetism in La2-x-yEuySrxCuO4 (x<=0.17; y<=0.2) has been studied by means of magnetization measurements up to 14 T. Our results clearly show that in the antiferromagnetic phase Dzyaloshinsky-Moriya (DM)superexchange causes Cu spin canting not only in the LTO phase but also in the LTLO and LTT phases. In La1.8Eu0.2CuO4 the canted DM-moment is about 50% larger than in pure La2CuO4 which we attribute to the larger octahedral tilt angle. We also find clear evidence that the size of the DM-moment does not change significantly at the structural transition at T_LT from LTO to LTLO and LTT. The most important change induced by the transition is a significant reduction of the magnetic coupling between the CuO2 planes. As a consequence, the spin-flip transition of the canted Cu spins which is observed in the LTO phase for magnetic field perpendicular to the CuO2 planes disappears in the LTT phase. The shape of the magnetization curves changes from the well known spin-flip type to a weak-ferromagnet type. However, no spontaneous weak ferromagnetism is observed even at very low temperatures, which seems to indicate that the interlayer decoupling in our samples is not perfect. Nonetheless, a small fraction (<15%) of the DM-moments can be remanently magnetized throughout the entire antiferromagnetically ordered LTT/LTLO phase, i.e. for T<T_LT and x<0.02. It appears that the remanent DM-moment is perpendicular to the CuO2 planes. For magnetic field parallel to the CuO2 planes we find that the critical field of the spin-flop transition decreases in the LTLO phase, which might indicate a competition between different in-plane anisotropies. To study the Cu spin magnetism in La2-x-yEuySrxCuO4, a careful analysis of the Van Vleck paramagnetism of the Eu3+ ions was performed.Comment: 22 pages, 27 figure

    Green Production of Anionic Surfactant Obtained from Pea Protein

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    A pea protein isolate was hydrolyzed by a double enzyme treatment method in order to obtain short peptide sequences used as raw materials to produce lipopeptides-based surfactants. Pea protein hydrolysates were prepared using the combination of Alcalase and Flavourzyme. The influence of the process variables was studied to optimize the proteolytic degradation to high degrees of hydrolysis. The average peptide chain lengths were obtained at 3–5 amino acid units after a hydrolysis of 30 min with the mixture of enzymes. Then, N-acylation in water, in presence of acid chloride (C12 and C16), carried out with a conversion rate of amine functions of 90%, allowed to obtain anionic surfactant mixtures (lipopeptides and sodium fatty acids). These two steps were performed in water, in continuous and did not generate any waste. This process was therefore in line with green chemistry principles. The surface activities (CMC, foaming and emulsifying properties) of these mixtures were also studied. These formulations obtained from natural renewable resources and the reactions done under environmental respect, could replace petrochemical based surfactants for some applications

    Conservative kidney management and kidney supportive care:core components of integrated care for people with kidney failure

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    Integrated kidney care requires synergistic linkage between preventative care for people at risk for chronic kidney disease and health services providing care for people with kidney disease, ensuring holistic and coordinated care as people transition between acute and chronic kidney disease and the 3 modalities of kidney failure management: conservative kidney management, transplantation, and dialysis. People with kidney failure have many supportive care needs throughout their illness, regardless of treatment modality. Kidney supportive care is therefore a vital part of this integrated framework, but is nonexistent, poorly developed, and/or poorly integrated with kidney care in many settings, especially in low- and middle-income countries. To address this, the International Society of Nephrology has (i) coordinated the development of consensus definitions of conservative kidney management and kidney supportive care to promote international understanding and awareness of these active treatments; and (ii) identified key considerations for the development and expansion of conservative kidney management and kidney supportive care programs, especially in low resource settings, where access to kidney replacement therapy is restricted or not available. This article presents the definitions for conservative kidney management and kidney supportive care; describes their core components with some illustrative examples to highlight key points; and describes some of the additional considerations for delivering conservative kidney management and kidney supportive care in low resource settings.</p

    Comparison between two methods of working length determination and its effect on radiographic extent of root canal filling: a clinical study [ISRCTN71486641]

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    BACKGROUND: Obtaining a correct working length is critical to the success of endodontic therapy. Different methods have been used to identify this crucial measurement. The Aim of this clinical study was to compare the effect of working length determination using apex locator alone or in combination with working length radiograph on the apical extent of root canal filling. METHODS: A total number of 66 patients, 151 canals were randomized into two groups, In group (I) working length was determined by apex locator alone, while in group (II) working length was determined by apex locator confirmed by working length radiograph, length of obturation was assessed, and the total number of radiographs was recorded. The data were analyzed using SAS system and T. tests were carried out. Statistical significance was considered to be P ≤ 0.05. RESULTS: Sixty seven canals in group I were treated with a mean distance from the tip of root canal filling to radiographic apex -0.5 mm ± 0.5 and a mean of a total number of radiographs of 2.0, while in group II eighty four canals were treated with a mean distance from the tip of root canal filling to radiographic apex -0.4 mm ± 0.5 and a mean of a total number of radiographs of 3.2. There was no statistically significant difference in the mean distance from the tip of root filling to radiographic apex between group I and group II (P > 0.05). CONCLUSION: The practice of using electronic apex locator in the determination of working length is useful and reliable with no statistical difference of the radiographic extent of root canal filling when using apex locator alone or in combination with working length radiograph. Under the clinical conditions of this study, it is suggested that the correct use of an apex locator alone could prevent the need for further diagnostic radiographs for determination of working length. This method can be useful in patients who need not to be exposed to repeated radiation because of mental, medical or oral conditions
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