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1.
Click Chemistry Mediated Functionalization of Vertical Nanowires for Biological Applications 下载免费PDF全文
Surendra Vutti Dr. Sanne Schoffelen Dr. Jessica Bolinsson Nina Buch‐Månson Prof. Nicolas Bovet Prof. Jesper Nygård Prof. Karen L. Martinez Prof. Morten Meldal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):496-500
Semiconductor nanowires (NWs) are gaining significant importance in various biological applications, such as biosensing and drug delivery. Efficient and controlled immobilization of biomolecules on the NW surface is crucial for many of these applications. Here, we present for the first time the use of the CuI‐catalyzed alkyne–azide cycloaddition and its strain‐promoted variant for the covalent functionalization of vertical NWs with peptides and proteins. The potential of the approach was demonstrated in two complementary applications of measuring enzyme activity and protein binding, which is of general interest for biological studies. The attachment of a peptide substrate provided NW arrays for the detection of protease activity. In addition, green fluorescent protein was immobilized in a site‐specific manner and recognized by antibody binding to demonstrate the proof‐of‐concept for the use of covalently modified NWs for diagnostic purposes using minute amounts of material. 相似文献
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3.
F. Frontera A. Basili D. Dal Fiume T. Franceschini G. Landini E. Morelli J. M. Poulsen S. Silvestri E. Costa D. Cardini et al. 《Il Nuovo Cimento C》1990,13(2):437-444
Summary The LAPEX payload is described in the configuration that will be launched to observe the supernova SN 1987A. The balloon flight
will be performed from Alice Springs (Australia) in April 1989 as a part of a NASA balloon campaign. The experiment will allow
simultaneous observations of source and background in order to minimize systematic errors due to background variations. The
limiting flux sensitivity of the instrument in the (20÷200) keV energy band is 4·10−6 ph/(cm2s keV) or ∼2.5 mCrab for a 104 s observation of SN 1987A. The presence of a57Co emission line in the SN 1987A photon spectrum could be detected down to an intensity level of ∼8·10−5 photons/cm2s as at 99.7% confidence level. The high resolution of the event timing (<0.1 ms) will make it possible to detect millisecond
pulsations with amplitudes down to ∼4% of the expected average flux from SN 1987A in the (20÷60) keV band.
To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee. 相似文献
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Maj-Britt Schmidt Andersen Mette Kristensen Claudine Manach Estelle Pujos-Guillot Sanne Kellebjerg Poulsen Thomas Meinert Larsen Arne Astrup Lars Dragsted 《Analytical and bioanalytical chemistry》2014,406(7):1829-1844
While metabolomics is increasingly used to investigate the food metabolome and identify new markers of food exposure, limited attention has been given to the validation of such markers. The main objectives of the present study were to (1) discover potential food exposure markers (PEMs) for a range of plant foods in a study setting with a mixed dietary background and (2) validate PEMs found in a previous meal study. Three-day weighed dietary records and 24-h urine samples were collected three times during a 6-month parallel intervention study from 107 subjects randomized to two distinct dietary patterns. An untargeted UPLC-qTOF-MS metabolomics analysis was performed on the urine samples, and all features detected underwent strict data analyses, including an iterative paired t test and sensitivity and specificity analyses for foods. A total of 22 unique PEMs were identified that covered 7 out of 40 investigated food groups (strawberry, cabbages, beetroot, walnut, citrus, green beans and chocolate). The PEMs reflected foods with a distinct composition rather than foods eaten more frequently or in larger amounts. We found that 23 % of the PEMs found in a previous meal study were also valid in the present intervention study. The study demonstrates that it is possible to discover and validate PEMs for several foods and food classes in an intervention study with a mixed dietary background, despite the large variability in such a dataset. Final validation of PEMs for intake of foods should be performed by quantitative analysis. Figure
Examples of two urinary exposure markers for cabbage (left) and beetroot (right) found in the study from an untargeted LC‐MS metabolomics analysis of urine samples and self‐reported food intake data 相似文献
6.
A high-performance liquid chromatographic method for the determination of 2-naphthylamine in urine using fluorescence detection was developed. The method validation analysis showed the method to be in analytical control, i.e. the distribution of the difference between the observed and true values of the method evaluation samples did not deviate significantly from the normal distribution. The recovery of the method was 85%. The entire run time of chromatography was 10 min using isocratic elution (acetonitrile-water, 35:65), and the retention time for 2-naphthylamine was 5.8 min. The relative short time of analysis in combination with the low limit of detection (0.272 nmol/l) makes the method potentially applicable for surveillance of occupational and environmental exposure to 2-nitronaphthalene. The developed method is presently used for measurement of 2-naphthylamine in urine samples from workers employed at factories, characterized by a low airborne exposure level of polycyclic aromatic hydrocarbons, i.e. in general less than 25 micrograms/m3. The urine samples of exposed workers (n = 95) showed a 2-naphthylamine range of up to 9.4 nmol/l, whereas unexposed control individuals (n = 114) showed a range of up to 0.87 nmol/l. 相似文献
7.
Catalytic Asymmetric Oxidative γ‐Coupling of α,β‐Unsaturated Aldehydes with Air as the Terminal Oxidant 下载免费PDF全文
Line Næsborg Vasco Corti Lars Astrup Leth Dr. Pernille H. Poulsen Prof. Karl Anker Jørgensen 《Angewandte Chemie (International ed. in English)》2018,57(6):1606-1610
A novel concept for catalytic asymmetric coupling reactions is presented. Merging organocatalysis with single‐electron oxidation by using a catalytic amount of a copper(II) salt and air as the terminal oxidant, we have developed a highly stereoselective carbon–carbon oxidative coupling reaction of α,β‐unsaturated aldehydes. The concept relies on the generation of a dienamine intermediate, which is oxidized to an open‐shell activated species that undergoes highly selective γ‐homo‐ and γ‐heterocoupling reactions. In the majority of examples presented, only a single stereoisomer was formed. 相似文献
8.
Ebbe Thue Poulsen 《Mathematische Zeitschrift》1965,90(4):286-309
Ohne ZusammenfassungAus dem Institut für Angewandte Mathematik, Heidelberg 相似文献
9.
T. Andersen O. Poulsen P.S. Ramanujam 《Journal of Quantitative Spectroscopy & Radiative Transfer》1976,16(6):521-527
The zero-field level-crossing technique has been used to determine radiative lifetimes of excited states in singly ionized zinc, cadmium, and mercury. The excited levels in Zn(II), Cd(II) and Hg(II) were populated by collisions between fast ions and helium gas. Particular attention has been paid to the systematic errors occurring in radiative lifetimes by this technique. The results are compared with the lifetimes obtained by beam-foil, phase-shift, delayed-coincidence techniques and theoretical calculations. 相似文献
10.
Poulsen TB 《Chemical communications (Cambridge, England)》2011,47(48):12837-12839
An efficient synthesis of the macrolactone core of the rakicidins is described. The rakicidins are cytotoxic lipopeptides with interesting cancer cell selectivities including HIF-1-independent hypoxia-selective cytotoxicity and anti-invasive activity. Access to the core may now allow establishment of preliminary SAR and exploration of routes to several members of rakicidins. 相似文献