TY - JOUR A1 - Kleinpeter, Erich A1 - Koch, Andreas A1 - Seidl, Peter R. T1 - Visualization and quantification of the anisotropic effect of C=C double bonds on 1H NMR spectra of highly congested hydrocarbons-indirect estimates of steric strain N2 - The anisotropic effect of the olefinic C=C double bond has been calculated by employing the NICS (nucleus independent chemical shift) concept and visualized as an anisotropic cone by a through space NMR shielding grid. Sign and size of this spatial effect on 1H chemical shifts of protons in norbornene, exo- and endo-2-methylnorbornenes, and in three highly congested tetracyclic norbornene analogs have been compared with the experimental 1H NMR spectra as far as published. 1H NMR spectra have also been calculated at the HF/6-31G* level of theory to get a full, comparable set of proton chemical shifts. Differences between ;(1H)/ppm and the calculated anisotropic effect of the C=C double bond are discussed in terms of the steric compression that occurs in the compounds studied. Y1 - 2008 UR - http://pubs.acs.org/doi/full/10.1021/jp801063t U6 - https://doi.org/10.1021/Jp801063t ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Werner, Peter A1 - Koch, Andreas T1 - Push-pull allenes-conjugation, (anti)aromaticity and quantification of the push-pull character JF - Tetrahedron N2 - Structures, H-1/C-13 chemical shifts, and pi electron distribution/conjugation of an experimentally available and theoretically completed set of push-pull allenes Acc(2)C=C=CDon(2) (Acc=F, CHO, CF3, C N; Don=t-Bu, OMe, OEt, SMe, SEt, NCH2R) have been computed at the OFT level of theory. Both orthogonal linear and orthogonal bent structures have been obtained. In the latter case the push-pull character could be quantified by the quotient method. The C-13 chemical shift of the central allene carbon atom C-2 and chemical shift differences Delta delta(C-1, C-2) and Delta delta(C-2, C-3) of allene carbon atoms proved to be a quantitative alternative. TSNMRS of ring-closed push-pull allenes have been computed in addition and were employed to identify polar, carbene-like and carbone-like canonical structures of these molecules. KW - Push-pull allenes KW - Push-pull character KW - C-13 NMR spectroscopy KW - Quotient method KW - TSNMRS KW - ICSS KW - Aromaticity Y1 - 2013 U6 - https://doi.org/10.1016/j.tet.2013.01.027 SN - 0040-4020 VL - 69 IS - 11 SP - 2436 EP - 2445 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Davidzon, Iary A1 - Ilbert, Olivier A1 - Faisst, Andreas L. A1 - Sparre, Martin A1 - Capak, Peter L. T1 - An Alternate Approach to Measure Specific Star Formation Rates at 2 < z < 7 JF - The astrophysical journal : an international review of spectroscopy and astronomical physics N2 - We trace the specific star formation rate (sSFR) of massive star-forming galaxies (greater than or similar to 10(10)M(circle dot)) from z similar to 2 to 7. Our method is substantially different from previous analyses, as it does not rely on direct estimates of star formation rate, but on the differential evolution of the galaxy stellar mass function (SMF). We show the reliability of this approach by means of semianalytical and hydrodynamical cosmological simulations. We then apply it to real data, using the SMFs derived in the COSMOS and CANDELS fields. We find that the sSFR is proportional to (1 + z)(1.1) (+/-) (0.2) at z > 2, in agreement with other observations but in tension with the steeper evolution predicted by simulations from z similar to 4 to 2. We investigate the impact of several sources of observational bias, which, however, cannot account for this discrepancy. Although the SMF of high-redshift galaxies is still affected by significant errors, we show that future large-area surveys will substantially reduce them, making our method an effective tool to probe the massive end of the main sequence of star-forming galaxies. KW - galaxies: evolution KW - galaxies: high-redshift KW - galaxies: star formation Y1 - 2018 U6 - https://doi.org/10.3847/1538-4357/aaa19e SN - 0004-637X SN - 1538-4357 VL - 852 IS - 2 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Kleeberg, Andreas A1 - Hupfer, Michael A1 - Gust, Giselher A1 - Salka, Ivette A1 - Pohlmann, Kirsten A1 - Grossart, Hans-Peter T1 - Intermittent riverine resuspension effects on phosphorus transformations and heterotrophic bacteria JF - Limnology and oceanography N2 - Intermittent riverine resuspension (IRR), a common phenomenon, was applied to investigate its effects on sedimentary resources availability and bacteria in the water column. This lab experiment used organic-rich lowland river sediment in a newly designed erosion chamber, the Benthic Water Column Simulator, generating well-defined ratios of shear velocity u* to turbulence intensity. Eight consecutive resuspension events, 1-8, were initiated at u* = 1.1 cm s(-1). Sedimentary and phosphorus entrainment decreased from 20.4 g m(-2) h(-1) and 111.6 mg m(-2) h(-1) at event 1 to 1.31 g m(-2) h(-1) and 18.7 mg m(-2) h(-1) at event 8, suggesting an exhaustion of particulate and dissolved sediment constituents. Entrainment of particle-associated (PA) bacteria (132.7 x 10(9)-251.1 x 10(9) cells m(-2) h(-1)) was strongly correlated to that of particles. Free-living (FL) bacteria (-27.6 x 10(9)-36.4 x 10(9) cells m(-2) h(-1)) were fractionally entrained. Numbers of PA bacteria remained low after each event, whereas those of FL bacteria strongly increased 5-15 h after an event because of growth due to increased availability of dissolved organic carbon and inorganic nutrients following each event. FL bacteria community structure also changed during IRR. The systematic changes over consecutive IRR cycles show a strong effect in all considered parameters that elude the typical single-event, steady-state experiments. IRR should thus be considered in two respects: experimental protocols on riverine water quality should be revised. In ecosystem modeling, IRR should be considered to better predict extent and effect of resuspension. Only IRR adequately reflects the natural interplay between hydrodynamics and organisms in rivers. Y1 - 2013 U6 - https://doi.org/10.4319/lo.2013.58.2.0635 SN - 0024-3590 SN - 1939-5590 VL - 58 IS - 2 SP - 635 EP - 652 PB - Wiley CY - Waco ER - TY - JOUR A1 - McHuron, Elizabeth A. A1 - Adamczak, Stephanie A1 - Arnould, John P. Y. A1 - Ashe, Erin A1 - Booth, Cormac A1 - Bowen, W. Don A1 - Christiansen, Fredrik A1 - Chudzinska, Magda A1 - Costa, Daniel P. A1 - Fahlman, Andreas A1 - Farmer, Nicholas A. A1 - Fortune, Sarah M. E. A1 - Gallagher, Cara A. A1 - Keen, Kelly A. A1 - Madsen, Peter T. A1 - McMahon, Clive R. A1 - Nabe-Nielsen, Jacob A1 - Noren, Dawn P. A1 - Noren, Shawn R. A1 - Pirotta, Enrico A1 - Rosen, David A. S. A1 - Speakman, Cassie N. A1 - Villegas-Amtmann, Stella A1 - Williams, Rob T1 - Key questions in marine mammal bioenergetics JF - Conservation physiology N2 - Bioenergetic approaches are increasingly used to understand how marine mammal populations could be affected by a changing and disturbed aquatic environment. There remain considerable gaps in our knowledge of marine mammal bioenergetics, which hinder the application of bioenergetic studies to inform policy decisions. We conducted a priority-setting exercise to identify high-priority unanswered questions in marine mammal bioenergetics, with an emphasis on questions relevant to conservation and management. Electronic communication and a virtual workshop were used to solicit and collate potential research questions from the marine mammal bioenergetic community. From a final list of 39 questions, 11 were identified as 'key'questions because they received votes from at least 50% of survey participants. Key questions included those related to energy intake (prey landscapes, exposure to human activities) and expenditure (field metabolic rate, exposure to human activities, lactation, time-activity budgets), energy allocation priorities, metrics of body condition and relationships with survival and reproductive success and extrapolation of data from one species to another. Existing tools to address key questions include labelled water, animal-borne sensors, mark-resight data from long-term research programs, environmental DNA and unmanned vehicles. Further validation of existing approaches and development of new methodologies are needed to comprehensively address some key questions, particularly for cetaceans. The identification of these key questions can provide a guiding framework to set research priorities, which ultimately may yield more accurate information to inform policies and better conserve marine mammal populations. Y1 - 2022 U6 - https://doi.org/10.1093/conphys/coac055 SN - 2051-1434 VL - 10 IS - 1 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Tschorn, Mira A1 - Rieckmann, Nina A1 - Arolt, Volker A1 - Beer, Katja A1 - Haverkamp, Wilhelm A1 - Martus, Peter A1 - Waltenberger, Johannes A1 - Müller-Nordhorn, Jacqueline A1 - Ströhle, Andreas T1 - Erkennungsgüte dreier deutschsprachiger Screeninginstrumente für Depression bei hospitalisierten Patienten mit koronarer Herzerkrankung T1 - Diagnostic Accuracy of German Depression Screenings in Patients with Coronary Heart Disease JF - Psychiatrische Praxis N2 - Ziel Vergleich der Erkennungsgüte von drei Depressions-Screeninginstrumenten bei Patienten mit koronarer Herzerkrankung (KHK). Methodik 1019 KHK-Patienten erhielten den Patient Health Questionnaire (PHQ-9 und PHQ-2) und die Hospital Anxiety and Depression Scale (HADS-D) sowie ein klinisches Interview (Composite International Diagnostic Interview) als Referenzstandard. Ergebnisse Bezüglich der Erkennungsgüte waren PHQ-9 und HADS-D dem PHQ-2 überlegen. Optimale Cut-off-Werte waren 7 (PHQ-9 und HADS-D) und 2 (PHQ-2). Schlussfolgerung PHQ-9 und HADS-D haben eine vergleichbare Diskriminationsfähigkeit für depressive Störungen bei KHK-Patienten. N2 - Objective To compare the diagnostic accuracy of German depression screening instruments in patients with coronary heart disease (CHD). Methods 1019 CHD patients completed the Patient Health Questionnaire (PHQ-9 and PHQ-2) and the Hospital Anxiety and Depression Scale (HADS-D). The Composite International Diagnostic Interview served as reference standard for "any depressive disorder" and "major depression". Results The accuracy of the PHQ-9 and the HADS-D was comparable according to the area under the curve, and both were superior to the PHQ-2. The optimal cut-off according to the Youden index (maximum sum of sensitivity and specificity) was 7 for both instruments. At this optimal cut-off, the PHQ-9 had a higher sensitivity compared to the HADS-D, but a lower specificity (below 68). Results remained similar when patients who reported that they currently underwent treatment for depression were excluded. Conclusion The PHQ-9 and the HADS-D have comparable overall diagnostic accuracy in CHD patients. In line with previous screening studies with CHD patients, the optimal cut-offs were below the cut-offs that are recommended in the literature. KW - coronary artery disease KW - depression KW - diagnosis KW - screening KW - validity Y1 - 2019 U6 - https://doi.org/10.1055/s-0042-123434 SN - 0303-4259 SN - 1439-0876 VL - 46 IS - 1 SP - 41 EP - 48 PB - Thieme CY - Stuttgart ER - TY - GEN A1 - Block, Inga A1 - Günter, Christina A1 - Duarte Rodrigues, Alysson A1 - Paasch, Silvia A1 - Hesemann, Peter A1 - Taubert, Andreas T1 - Carbon Adsorbents from Spent Coffee for Removal of Methylene Blue and Methyl Orange from Water T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Activated carbons (ACs) were prepared from dried spent coffee (SCD), a biological waste product, to produce adsorbents for methylene blue (MB) and methyl orange (MO) from aqueous solution. Pre-pyrolysis activation of SCD was achieved via treatment of the SCD with aqueous sodium hydroxide solutions at 90 °C. Pyrolysis of the pretreated SCD at 500 °C for 1 h produced powders with typical characteristics of AC suitable and effective for dye adsorption. As an alternative to the rather harsh base treatment, calcium carbonate powder, a very common and abundant resource, was also studied as an activator. Mixtures of SCD and CaCO3 (1:1 w/w) yielded effective ACs for MO and MB removal upon pyrolysis needing only small amounts of AC to clear the solutions. A selectivity of the adsorption process toward anionic (MO) or cationic (MB) dyes was not observed. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1155 KW - water KW - spent coffee KW - dye adsorption KW - methylene blue KW - methyl orange KW - calcium carbonate KW - activated carbon KW - water treatment KW - dye removal Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-521653 SN - 1866-8372 IS - 14 ER - TY - JOUR A1 - Block, Inga A1 - Günter, Christina A1 - Duarte Rodrigues, Alysson A1 - Paasch, Silvia A1 - Hesemann, Peter A1 - Taubert, Andreas T1 - Carbon adsorbents from spent coffee for removal of methylene blue and methyl orange from water JF - Materials / Molecular Diversity Preservation International N2 - Activated carbons (ACs) were prepared from dried spent coffee (SCD), a biological waste product, to produce adsorbents for methylene blue (MB) and methyl orange (MO) from aqueous solution. Pre-pyrolysis activation of SCD was achieved via treatment of the SCD with aqueous sodium hydroxide solutions at 90 °C. Pyrolysis of the pretreated SCD at 500 °C for 1 h produced powders with typical characteristics of AC suitable and effective for dye adsorption. As an alternative to the rather harsh base treatment, calcium carbonate powder, a very common and abundant resource, was also studied as an activator. Mixtures of SCD and CaCO3 (1:1 w/w) yielded effective ACs for MO and MB removal upon pyrolysis needing only small amounts of AC to clear the solutions. A selectivity of the adsorption process toward anionic (MO) or cationic (MB) dyes was not observed. KW - water KW - spent coffee KW - dye adsorption KW - methylene blue KW - methyl orange KW - calcium carbonate KW - activated carbon KW - water treatment KW - dye removal Y1 - 2021 U6 - https://doi.org/10.3390/ma14143996 SN - 1996-1944 VL - 14 IS - 14 PB - Molecular Diversity Preservation International CY - Basel ER -