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31.
Johanna Rajasärkkä Jani Koponen Riikka Airaksinen Hannu Kiviranta Marko Virta 《Analytical and bioanalytical chemistry》2014,406(23):5695-5702
Bioluminescent Saccharomyces cerevisiae yeast-based bioreporters were used to monitor bisphenol A and other estrogenic chemicals in thermal paper samples collected mainly from Finland on two occasions in 2010/2011, and 2013. The bisphenol A-targeted (BPA-R) and the human oestrogen receptor (hERα) bioreporters were applied to analyse both non-treated and extracted paper samples. Bisphenol A was readily bioavailable to the yeast bioreporters on the non-treated paper samples without any pre-treatment. Detected concentrations ranged from a detection limit of 9–142 μg/g to over 20 mg/g of bisphenol A equivalents in the thermal papers. Low bisphenol A like activities were detected in many samples, and were considered to be caused by residual bisphenol A or other types of bisphenols, such as bisphenol S. Most of the thermal paper samples were toxic to the yeast bioreporters. The toxicity did not, however, depend on the bisphenol A concentration of the samples. The yeast bioreporters were demonstrated to be a robust and cost-efficient method to monitor thermal paper samples for their bisphenol A content and estrogenicity. Thermal paper was considered as a potential BPA source for both human exposure and environmental emission. 相似文献
32.
A practical comparison of MQMAS techniques 总被引:3,自引:0,他引:3
A systematic experimental evaluation of several approaches to multiple-quantum MAS NMR was performed for spin-5/2 nuclei using (27)Al NMR of the aluminosilicate andalusite and the porous aluminum phosphate AlPO(4)-14 as model. Experiments were conducted in the fields of 9.4 and 17.6T using magic-angle spinning frequencies up to 30kHz and rf-field strengths of 250 and 120kHz. Numerical SIMPSON optimizations of the NMR parameters were performed alongside the experimental evaluations. Both theory and experiment show that the optimization is most critical for the species in the sample that have the largest quadrupolar coupling constant. For 5QMAS experiments it could be confirmed that the highest available rf-field strength and rotation frequency are favorable for the efficiency of the experiments. For 3QMAS experiments of sites with moderate quadrupolar coupling constants optimum results were obtained at less stringent conditions. The comparison of a FAM II-modification and DFS gave the expected improvement by a factor of about two with respect to a rectangular pulse. No significant difference between these techniques concerning the signal-to-noise ratios was obtained. An actual improvement of the isotropic resolution by a factor of about two was obtained going from 3QMAS to 5QMAS. In addition the resolution of the spectra increases by a factor of about two going from 9.4 to 17.6T. 相似文献
33.
Veselin Nasufović Dr. Florian Küllmer Johanna Bößneck Dr. Hans-Martin Dahse Dr. Helmar Görls Dr. Peter Bellstedt Dr. Pierre Stallforth Prof. Dr. Hans-Dieter Arndt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(45):11633-11642
The first total synthesis of the actin-stabilizing marine natural product geodiamolide H was achieved. Solid-phase based peptide assembly paired with scalable stereoselective syntheses of polyketide building blocks and an optimized esterification set the stage for investigating the key ring-closing metathesis. Geodiamolide H and synthetic analogues were characterized for their toxicity and for antiproliferative effects in cellulo, by characterising actin polymerization induction in vitro, and by docking on the F-actin target and property computation in silico, for a better understanding of structure-activity relationships (SAR). A non-natural analogue of geodiamolide H was discovered to be most potent in the series, suggesting significant potential for tool compound design. 相似文献
34.
Theoretical stability,thin film synthesis and transport properties of the Mon +1GaCn MAX phase
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Rahele Meshkian Arni Sigurdur Ingason Martin Dahlqvist Andrejs Petruhins Unnar B. Arnalds Fridrik Magnus Jun Lu Johanna Rosen 《固体物理学:研究快报》2015,9(3):197-201
The phase stability of Mon +1GaCn has been investigated using ab‐initio calculations. The results indicate stability for the Mo2GaC phase only, with a formation enthalpy of –0.4 meV per atom. Subsequent thin film synthesis of Mo2GaC was performed through magnetron sputtering from elemental targets onto Al2O3 [0001], 6H‐SiC [0001] and MgO [111] substrates within the temperature range of 500 °C and 750 °C. High structural quality films were obtained for synthesis on MgO [111] substrates at 590 ºC. Evaluation of transport properties showed a superconducting behavior with a critical temperature of approximately 7 K, reducing upon the application of an external magnetic field. The results point towards the first superconducting MAX phase in thin film form. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
35.
Waldemar Hoffmann Johanna Hofmann Kevin Pagel 《Journal of the American Society for Mass Spectrometry》2014,25(3):471-479
Recent works using ion mobility-mass spectrometry (IM-MS) have highlighted the power of this instrumental configuration to tackle one of the greatest challenges in glycomics and glycoproteomics: the existence of isobaric isomers. For a successful separation of species with identical mass but different structure via IM-MS, it is crucial to have sufficient IM resolution. In commercially available IM-MS instruments, however, this resolution is limited by the design of the instrument and usually cannot be increased at-will without extensive modifications. Here, we present a systematic approach to improve the resolving capability of IM-MS instruments using so-called energy-resolved ion mobility-mass spectrometry. The technique utilizes the fact that individual components in an isobaric mixture fragment at considerably different energies when activated in the gas phase via collision-induced dissociation (CID). As a result, certain components can be suppressed selectively at increased CID activation energy. Using a mixture of four isobaric carbohydrates, we show that each of the individual sugars can be resolved and unambiguously identified even when their drift times differ by as little as 3 %. However, the presented results also indicate that a certain difference in the gas-phase stability of the individual components is crucial for a successful separation via energy-resolved IM-MS. Figure
? 相似文献
36.
Parks Conor D. Gaieb Zied Chiu Michael Yang Huanwang Shao Chenghua Walters W. Patrick Jansen Johanna M. McGaughey Georgia Lewis Richard A. Bembenek Scott D. Ameriks Michael K. Mirzadegan Tara Burley Stephen K. Amaro Rommie E. Gilson Michael K. 《Journal of computer-aided molecular design》2020,34(2):99-119
Journal of Computer-Aided Molecular Design - The Drug Design Data Resource (D3R) aims to identify best practice methods for computer aided drug design through blinded ligand pose prediction and... 相似文献
37.
Kirsten Berger Johanna Josefine Ostberg-Potthoff Tamara Bakuradze Peter Winterhalter Elke Richling 《Molecules (Basel, Switzerland)》2020,25(22)
Red fruits and their juices are rich sources of polyphenols, especially anthocyanins. Some studies have shown that such polyphenols can inhibit enzymes of the carbohydrate metabolism, such as α-amylase and α-glucosidase, that indirectly regulate blood sugar levels. The presented study examined the in vitro inhibitory activity against α-amylase and α-glucosidase of various phenolic extracts prepared from direct juices, concentrates, and purees of nine different berries which differ in their anthocyanin and copigment profile. Generally, the extracts with the highest phenolic content—aronia (67.7 ± 3.2 g GAE/100 g; cyanidin 3-galactoside; chlorogenic acid), pomegranate (65.7 ± 7.9 g GAE/100 g; cyanidin 3,5-diglucoside; punicalin), and red grape (59.6 ± 2.5 g GAE/100 g; malvidin 3-glucoside; quercetin 3-glucuronide)—showed also one of the highest inhibitory activities against α-amylase (326.9 ± 75.8 μg/mL; 789.7 ± 220.9 μg/mL; 646.1 ± 81.8 μg/mL) and α-glucosidase (115.6 ± 32.5 μg/mL; 127.8 ± 20.1 μg/mL; 160.6 ± 68.4 μg/mL) and, partially, were even more potent inhibitors than acarbose (441 ± 30 μg/mL; 1439 ± 85 μg/mL). Additionally, the investigation of single anthocyanins and glycosylated flavonoids demonstrated a structure- and size-dependent inhibitory activity. In the future in vivo studies are envisaged. 相似文献
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