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251.
Erich Hesse 《Journal of Ornithology》1909,57(3):322-365
Ohne Zusammenfassung 相似文献
252.
Quantitative analysis of human centrosome architecture by targeted proteomics and fluorescence imaging
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Centrioles are essential for the formation of centrosomes and cilia. While numerical and/or structural centrosomes aberrations are implicated in cancer, mutations in centriolar and centrosomal proteins are genetically linked to ciliopathies, microcephaly, and dwarfism. The evolutionarily conserved mechanisms underlying centrosome biogenesis are centered on a set of key proteins, including Plk4, Sas‐6, and STIL, whose exact levels are critical to ensure accurate reproduction of centrioles during cell cycle progression. However, neither the intracellular levels of centrosomal proteins nor their stoichiometry within centrosomes is presently known. Here, we have used two complementary approaches, targeted proteomics and EGFP‐tagging of centrosomal proteins at endogenous loci, to measure protein abundance in cultured human cells and purified centrosomes. Our results provide a first assessment of the absolute and relative amounts of major components of the human centrosome. Specifically, they predict that human centriolar cartwheels comprise up to 16 stacked hubs and 1 molecule of STIL for every dimer of Sas‐6. This type of quantitative information will help guide future studies of the molecular basis of centrosome assembly and function. 相似文献
253.
Authors index 总被引:1,自引:0,他引:1
Lehmann Johannes Weigl Doris Peter Inka Droppelmann Klaus Gebauer Gerhard Goldbach Heiner Zech Wolfgang 《Plant and Soil》1999,210(2):249-262
In a runoff irrigation system in Northern Kenya, we studied the nutrient interactions of sole cropped and alley cropped Sorghum
bicolor (L.) Moench and Acacia saligna (Labill.) H.L. Wendl. The trees were pruned once before the cropping season and the
biomass was used as fodder for animals. The nutrient contents in leaf tissue, soil and soil solution were monitored and the
uptake of applied tracers (15N, Sr) was followed. The grain yield of alley cropped sorghum was similar to or slightly higher than in monoculture and did
not decrease near the tree-crop interface. Foliar N and Ca contents of the crop were higher in the agroforestry combination
than in monoculture, corresponding to higher soil N and Ca contents. Soil solution and soil mineral N dynamics indicate an
increase of N under the tree row and unused soil N at the topsoil in the alley of the sole cropped trees as well as below
60 cm depth in the crop monoculture. The N use efficiency of the tree+crop combination was higher than the sole cropped trees
or crops. Competition was observed for Zn and Mn of both tree and crop whereas for Ca only the tree contents decreased. P,
K, Mg and Fe dynamics were not affected by alley cropping at our site. The lower uptake of applied Sr by trees in alley cropping
compared to those of the monoculture stand suggested a lower competitiveness of the acacia than sorghum, which did not show
lower Sr contents when intercropped. The study showed the usefulness of combining soil and plant analyses together with tracer
techniques identifying nutrient competition, nutrient transfer processes and the complementary use of soil nutrients, as the
main features of the tree-crop combination.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
254.
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256.
Franz Schwarzenberger Kristina Tomov Dana Hole
kov Bernd Matern Erich Mstl 《Zoo biology》1996,15(2):159-171
The metabolism and excretion of progesterone in different animal species results in several fecal 5-reduced progesterone metabolites (pregnanes), which in recent studies were quantified using progesterone antibodies. To increase the accuracy of fecal 20-oxo-pregnane evaluations in the black rhinoceros, enzyme immunoassays (EIA) using antibodies against 5α-pregnane-3β-ol-20-one 3HS:BSA (5α-20-one EIA) and 5β-pregnane-3α-ol-20-one 3HS:BSA (5β-20-one EIA) were developed. The assays showed high crossreactivities with pregnanes containing a 20-oxo group and are referred to as group-specific; results of these assays were compared with an EIA using an antibody against 6HS-progesterone (4-ene-20-one EIA). Fecal samples of both subspecies of the black rhinoceros (Diceros bicornis michaeli, n = 5, and Diceros bicornis minor, n = 1) during pregnancy were collected 1–3 times/week. HPLC separation showed three major immunoreactive fecal 20-oxo-pregnane peaks; their elution profiles and different crossreactivities in the three EIAs provided strong evidence that these peaks are 5α-pregnane-3, 20-dione, 5α-pregnane-3α-ol-20-one, and 5α-pregnane-3β-ol-20-one. Pregnane values in the pregnant animals continuously increased between months 3–7 and were significantly (P < 0.01) elevated above the levels of nonpregnant animals (0.2 μg/g) by week 11. During months 6–13 concentrations in the 5α-20-one and in the 5β-20-one EIA (5–11 μg/g) were significantly (P < 0.01) higher than in the 4-ene-20-one EIA (1.5–3 μg/g). In conclusion, the immunoreactive fecal 20-oxo-pregnane metabolites in the black rhinoceros are determined more accurately with antibodies against pregnane-20-one-C3 conjugates, as compared with a progesterone antibody. © 1996 Wiley-Liss, Inc. 相似文献
257.
PP2A‐B′γ modulates foliar trans‐methylation capacity and the formation of 4‐methoxy‐indol‐3‐yl‐methyl glucosinolate in Arabidopsis leaves
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258.
Amino acid transporter mutants of Arabidopsis provides evidence that a non‐mycorrhizal plant acquires organic nitrogen from agricultural soil
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Ulrika Ganeteg Iftikhar Ahmad Sandra Jämtgård Camila Aguetoni‐Cambui Erich Inselsbacher Henrik Svennerstam Susanne Schmidt Torgny Näsholm 《Plant, cell & environment》2017,40(3):413-423
Although organic nitrogen (N) compounds are ubiquitous in soil solutions, their potential role in plant N nutrition has been questioned. We performed a range of experiments on Arabidopsis thaliana genetically modified to enhance or reduce root uptake of amino acids. Plants lacking expression of the Lysine Histidine Transporter 1 (LHT1) displayed significantly lower contents of 13C and 15N label and of U‐13C5,15N2 L‐glutamine, as determined by liquid chromatography–mass spectrometry when growing in pots and supplied with dually labelled L‐glutamine compared to wild type plants and LHT1‐overexpressing plants. Slopes of regressions between accumulation of 13C‐labelled carbon and 15N‐labelled N were higher for LHT1‐overexpressing plants than wild type plants, while plants lacking expression of LHT1 did not display a significant regression between the two isotopes. Uptake of labelled organic N from soil tallied with that of labelled ammonium for wild type plants and LHT1‐overexpressing plants but was significantly lower for plants lacking expression of LHT1. When grown on agricultural soil plants lacking expression of LHT1 had the lowest, and plants overexpressing LHT1 the highest C/N ratios and natural δ15N abundance suggesting their dependence on different N pools. Our data show that LHT1 expression is crucial for plant uptake of organic N from soil. 相似文献
259.
Medium chain fatty acids in intrauterine growth restricted and small for gestational age pregnancies
Silvia Visentin Sara Crotti Elena Donazzolo Sara D’Aronco Donato Nitti Erich Cosmi Marco Agostini 《Metabolomics : Official journal of the Metabolomic Society》2017,13(5):54
Introduction
Low birth weight is associated with an increased risk of heart disease, high blood pressure and diabetes in adult life. Fetal growth is determined by nutrient availability, which is related to placenta nutrient transport. Medium chain fatty acids (MCFAs) are a particular class of nutrients, known to be a readily available energy source. Until now no data are reported on these MCFAs in low birth weight fetus.Aim
This is a prospective study conducted in a tertiary center of prenatal diagnosis to investigate the maternal and fetal MCFAs levels in appropriate for gestational age (AGA), intrauterine growth restricted (IUGR), and small for gestational age (SGA) pregnancies.Method
The plasmatic levels of MCFAs in AGA, IUGR and SGA mother–infant pairs were quantified by gas chromatography–mass spectrometry. The analytical method had a linearity range of 0.1–50 mg/L and a limit of quantification of 0.03 mg/L. Reduced fetal growth was defined as an estimated fetal weight below the 3rd–10th percentile for gestational age, with (IUGR) or without (SGA) fetal Doppler abnormalities.Result
Maternal and fetal MCFAs plasma levels were significantly different among SGA, IUGR and AGA groups. Additionally, the observed MCFAs fetal to maternal ratio is >1 for IUGR group, whilst for SGA and AGA the fetal to maternal ratio is less than one.Conclusion
Changes in MCFAs levels in fetal and maternal plasma are not related to placental functionality or nutrients availability, suggesting the presence of a de novo biosynthesis.260.