139 research outputs found

    Hydrogen Spectroscopy with a Lamb-shift Polarimeter - An Alternative Approach Towards Anti-Hydrogen Spectroscopy Experiments

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    A Lamb-shift polarimeter, which has been built for a fast determination of the polarization of protons and deuterons of an atomic-beam source and which is frequently used in the ANKE experiment at COSY-J\"ulich, is shown to be an excellent device for atomic-spectroscopy measurements of metastable hydrogen isotopes. It is demonstrated that magnetic and electric dipole transitions in hydrogen can be measured as a function of the external magnetic field, giving access to the full Breit-Rabi diagram for the 22S1/22^2S_{1/2} and the 22P1/22^2P_{1/2} states. This will allow the study of hyperfine structure, gg factors and the classical Lamb shift. Although the data are not yet competitive with state-of-the-art measurements, the potential of the method is enormous, including a possible application to anti-hydrogen spectroscopy.Comment: 6 pages, 7 figures, accepted by European Physical Journal

    Early and late steps of quinine biosynthesis

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    Function of sesquiterpenes from Schizophyllum commune in interspecific interactions

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    Chromane derivatives from underground parts of Iris tenuifolia and their in vitro antimicrobial, cytotoxicity and antiproliferative evaluation

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    Phytochemical investigation of the ethanol extract of underground parts of Iris tenuifolia Pall. afforded five new compounds; an unusual macrolide termed moniristenulide (1), 5-methoxy-6,7-methylenedioxy-4-O-2â€Č-cycloflavan (2), 5,7,2â€Č,3â€Č-tetrahydroxyflavanone (3), 5-hydroxy-6,7-dimethoxyisoflavone-2â€Č-O-ÎČ-d-glucopyranoside (9), 5,2â€Č,3â€Č-dihydroxy-6,7-dimethoxyisoflavone (10), along with seven known compounds (4–8, 11–12). The structures of all purified compounds were established by analysis of 1D and 2D NMR spectroscopy and HR-ESI-MS. The antimicrobial activity of the compounds 1–3, 5, 9, and 10 was investigated using the agar diffusion method against fungi, Gram-positive and Gram-negative bacteria. In consequence, new compound 3 was found to possess the highest antibacterial activity against Enterococcus faecalis VRE and Mycobacterium vaccae. Cell proliferation and cytotoxicity tests were also applied on all isolated compounds and plant crude extract in vitro with the result of potent inhibitory effect against leukemia cells. In particular, the newly discovered isoflavone 10 was active against both of the leukemia cells K-562 and THP-1 while 4–6 of the flavanone type compounds were active against only THP-1

    The Polarized H and D Atomic Beam Source for ANKE at COSY-J\"ulich

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    A polarized atomic beam source was developed for the polarized internal storage-cell gas target at the magnet spectrometer ANKE of COSY-J\"ulich. The intensities of the beams injected into the storage cell, measured with a compression tube, are 7.5⋅10167.5\cdot 10^{16} hydrogen atoms/s (two hyperfine states) and 3.9⋅10163.9\cdot 10^{16} deuterium atoms/s (three hyperfine states). For the hydrogen beam the achieved vector polarizations are pz≈±0.92p_{\rm z}\approx\pm0.92. For the deuterium beam, the obtained combinations of vector and tensor (pzzp_{\rm zz}) polarizations are pz≈±0.90p_{\rm z}\approx\pm 0.90 (with a constant pzz≈+0.86p_{\rm zz}\approx +0.86), and pzz=+0.90p_{\rm zz}=+0.90 or pzz=−1.71p_{\rm zz}=-1.71 (both with vanishing pzp_{\rm z}). The paper includes a detailed technical description of the apparatus and of the investigations performed during the development.Comment: 18 pages, 26 figures, 4 table

    The Fall Armyworm Spodoptera frugiperda Utilizes Specific UDP-Glycosyltransferases to Inactivate Maize Defensive Benzoxazinoids

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    The relationship between plants and insects is continuously evolving, and many insects rely on biochemical strategies to mitigate the effects of toxic chemicals in their food plants, allowing them to feed on well-defended plants. Spodoptera frugiperda, the fall armyworm (FAW), accepts a number of plants as hosts, and has particular success on plants of the Poaceae family such as maize, despite their benzoxazinoid (BXD) defenses. BXDs stored as inert glucosides are converted into toxic aglucones by plant glucosidases upon herbivory. DIMBOA, the main BXD aglucone released by maize leaves, can be stereoselectively re-glucosylated by UDP-glycosyltransferases (UGTs) in the insect gut, rendering it non-toxic. Here, we identify UGTs involved in BXD detoxification by FAW larvae and examine how RNAi-mediated manipulation of the larval glucosylation capacity toward the major maize BXD, DIMBOA, affects larval growth. Our findings highlight the involvement of members of two major UGT families, UGT33 and UGT40, in the glycosylation of BXDs. Most of the BXD excretion in the frass occurs in the form of glucosylated products. Furthermore, the DIMBOA-associated activity was enriched in the gut tissue, with a single conserved UGT33 enzyme (SfUGT33F28) being dedicated to DIMBOA re-glucosylation in the FAW gut. The knock-down of its encoding gene reduces larval performance in a strain-specific manner. This study thus reveals that a single UGT enzyme is responsible for detoxification of the major maize-defensive BXD in this pest insect. © Copyright © 2020 Israni, Wouters, Luck, Seibel, Ahn, Paetz, Reinert, Vogel, Erb, Heckel, Gershenzon and Vassão

    Assessing The Impact Of Socioeconomic Status On Maternal And Cord Serum Omega-3 Polyunsaturated Fatty Acid Levels

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    Background: Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) modulate inflammation throughout the lifespan and are essential in fetal growth and development. Previous studies have demonstrated that individuals with lower socioeconomic status (SES) may be at risk for low intake of n-3 PUFAs; however, no research has compared the concentrations of these nutrients present in maternal and cord serum between markers of SES. Significance of Problem: Individuals with low serum levels of n-3 PUFAs may suffer from unfavorable birth and pregnancy outcomes. Therefore, it is important to identify populations who may have decreased serum levels of these nutrients in order to provide nutritional recommendations to optimize prenatal care. Objective: The purpose of this study is to assess the relationship between markers of SES and levels of n-3 PUFAs in maternal and cord serum in a group of patients delivering at a Midwest Academic Medical Center. Methods: An IRB-approved study enrolled mother-infant pairs (n=55) at the time of delivery for collection of maternal and cord serum samples. n-3 PUFA levels quantified included Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), and total n-3 PUFAs. Markers of SES include private vs public insurance, income ≀150% of the poverty line vs \u3e150%, and college degree earners vs no college degree. Descriptive statistics were run for all variables. The Mann-Whitney U test was used to assess differences in n-3 PUFA levels between SES groups. A p\u3c0.05 was considered statistically significant. Results: Median gestational age at delivery was 39.3 weeks in this cohort. Significantly higher nutrient levels were present in college-educated mothers vs less than college-educated mothers for maternal EPA (9.44 ”g/mL vs 5.13 ”g/mL, p=0.010), cord EPA (1.88 ”g/mL vs 1.40 ”g/mL, p=0.011), cord DHA (37.96 ”g/mL vs 32.80 ”g/mL, p=0.014), and total cord n-3 PUFAs (44.23 ”g/mL vs 39.34 ”g/mL, p=0.024). Median cord EPA levels were significantly higher in those with private insurance compared to public (1.79 ”g/mL, 1.18 ”g/mL, p=0.022). Additionally, median cord EPA levels were significantly higher in those \u3e150% the poverty line (1.79 ”g/mL, 1.10 ”g/mL, p=0.030). No other significant differences were observed between SES groups and n-3 PUFA levels. Conclusion: Our findings suggest that individuals with lower SES may be at risk for lower serum levels of n-3 PUFAs in pregnancy, which could predispose them to adverse birth and pregnancy outcomes. Future studies should focus on replicating these results in a larger, more heterogeneous sample and should consider analyzing additional markers of SES.https://digitalcommons.unmc.edu/chri_forum/1051/thumbnail.jp
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