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  • 1
    Language: English
    In: The Journal of organic chemistry, 17 May 2013, Vol.78(10), pp.4905-12
    Description: Four upper rim bis-monopyrrolotetrathiafulvalene-calix[4]arene conjugates 2a,b and 3a,b have been efficiently synthesized using a modular construction approach. The new compounds feature a molecular tweezer architecture with a quasi-parallel arrangement of redox-active tetrathiafulvalene (TTF) arms, which serve as the guest binding centers. Complexation studies using UV/vis binding titrations revealed a high affinity of the calixarene-TTF receptors for planar electron-deficient guests, leading to formation of deeply colored charge-transfer complexes in solution. The binding efficiency of the receptors depends on the flexibility of the calixarene scaffolds and the electronic nature of the TTF arms: the highest binding efficiency is shown by receptor 2b, featuring a highly preorganized molecular structure and an electron-rich TTF moiety.
    Keywords: Calixarenes -- Chemistry ; Heterocyclic Compounds -- Chemistry ; Phenols -- Chemistry
    ISSN: 00223263
    E-ISSN: 1520-6904
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  • 2
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  • 3
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  • 4
    In: PLoS ONE, 2015, Vol.10(3)
    Description: The Smoothing Spline ANOVA (SS-ANOVA) requires a specialized construction of basis and penalty terms in order to incorporate prior knowledge about the data to be fitted. Typically, one resorts to the most general approach using tensor product splines. This implies severe constraints on the correlation structure, i.e. the assumption of isotropy of smoothness can not be incorporated in general. This may increase the variance of the spline fit, especially if only a relatively small set of observations are given. In this article, we propose an alternative method that allows to incorporate prior knowledge without the need to construct specialized bases and penalties, allowing the researcher to choose the spline basis and penalty according to the prior knowledge of the observations rather than choosing them according to the analysis to be done. The two approaches are compared with an artificial example and with analyses of fixation durations during reading.
    Keywords: Research Article
    E-ISSN: 1932-6203
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  • 5
    Language: English
    In: Journal of the American Chemical Society, 28 February 2018, Vol.140(8), pp.2718-2721
    Description: We introduce a selective and cell-permeable calcium sensor for photoacoustics (CaSPA), a versatile imaging technique that allows for fast volumetric mapping of photoabsorbing molecules with deep tissue penetration. To optimize for Ca-dependent photoacoustic signal changes, we synthesized a selective metallochromic sensor with high extinction coefficient, low quantum yield, and high photobleaching resistance. Micromolar concentrations of Ca lead to a robust blueshift of the absorbance of CaSPA, which translated into an accompanying decrease of the peak photoacoustic signal. The acetoxymethyl esterified sensor variant was readily taken up by cells without toxic effects and thus allowed us for the first time to perform live imaging of Ca fluxes in genetically unmodified cells and heart organoids as well as in zebrafish larval brain via combined fluorescence and photoacoustic imaging.
    Keywords: Calcium ; Imaging-Procedure ; Extinction-Coefficient ; Quantum-Efficiency ; Absorption-Coefficient ; Toxic-Effect ; Photoacoustics ; Blue-Shift ; Calcium ; Bildgebungsverfahren ; Extinktionskoeffizient ; Quantenausbeute ; Absorptionskoeffizient ; Toxische Einwirkung ; Photoakustik ; Blauverschiebung ; Chemistry;
    ISSN: 00027863
    E-ISSN: 1520-5126
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  • 6
    Language: English
    In: Fiscal Studies, March, 2013, Vol.34, p.109(27)
    Description: To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1111/j.1475-5890.2013.00179.x/abstract Byline: Michael Pfaffermayr(1), Matthias Stockl(2), Hannes Winner(3) Keywords: corporate taxation; capital structure; firm age Abstract This paper analyses the relationship between corporate taxation, firm age and debt. We adapt a standard model of capital structure choice under corporate taxation, focusing on the financing and investment decisions typically faced by a firm. Our model suggests that the debt ratio is associated positively with the corporate tax rate and negatively with firm age. Further, we predict that the tax-induced advantage of debt is more important for older firms than for younger ones. To test these hypotheses empirically, we use a cross-section of around 405,000 firms from 35 European countries and 127 NACE three-digit industries. In line with previous research, we find that a firm's debt ratio increases with the corporate tax rate. Further, we observe that older firms exhibit smaller debt ratios than their younger counterparts. Finally, consistent with our theoretical model, we find a positive interaction between corporate taxation and firm age, indicating that the impact of corporate taxation on debt increases over a firm's lifetime. Author Affiliation: (1)University of Innsbruck; Austrian Institute for Economic Research (WIFO) (Michael.Pfaffermayr@uibk.ac.at) (2)University of Salzburg (3)University of Salzburg; Austrian Institute for Economic Research (WIFO) (Hannes.Winner@sbg.ac.at) Article Note: (*) Submitted November 2010. The authors are grateful to Simon Loretz, Harald Oberhofer and seminar participants at the annual conferences of the International Institute of Public Finance in Maastricht, the European Economic Association in Barcelona, the Spanish Economic Association in Zaragoza, the Austrian Economic Association in Linz, the Universities of Innsbruck and Salzburg as well as the joint workshop of the Vienna University of Economics and Business and the Oxford Centre for Business Taxation in Vienna. Financial support from the Jubilaumsfonds of the Austrian National Bank (OeNB, project no. 12459) is gratefully acknowledged.
    Keywords: Capital Structure -- Analysis ; Tax Rates -- Analysis ; Corporate Taxes -- Analysis
    ISSN: 0143-5671
    Source: Cengage Learning, Inc.
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  • 7
    Language: English
    In: Procedia Environmental Sciences, 2013, Vol.19, pp.543-552
    Description: Large weighable lysimeters allow a precise determination of the soil water balance and the quantification of both water exchange at the soil-atmosphere interface and the flux below the root zone toward the groundwater. If well embedded into an equally-vegetated environment, they reach a hitherto unprecedented accuracy in estimating precipitation (P) by rain, dew, fog, rime and snow, and evapotranspiration (ET). Lysimeters largely avoid errors made by traditional measurement systems, such as the wind error of Hellmann rain gauges, the island error of class-A pans, or errors from soil-water measurements that are subject to subsurface heterogeneity. If the amount of seepage water is added to the lysimeter mass, temporal changes of the lysimeter mass can be used to solve the water balance equation for atmospheric fluxes. Increasing mass indicates P, decreasing mass ET. The determination of the net water balance (sum of P and ET) is accurate and robust. A problem arises in the separate estimation of the underlying P and ET fluxes, because weight differences in specified time intervals are affected by stochastic fluctuations due to mechani- cal vibration, which may be caused by wind or other factors. The aim of this study is to evaluate algorithms that aim on eliminating the effects of these fluctuations and to estimate actual fluxes across the soil-atmosphere boundary and the soil water balance from lysimeter measurements. We use synthetic and real measured data from large lysimeters to test which strategies of data evaluation can be applied, and which degree of accuracy can be reached.
    Keywords: Large Lysimeter ; Et Measurement ; Precipitation Measurement ; Environmental Sciences
    ISSN: 1878-0296
    E-ISSN: 1878-0296
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  • 8
    Language: English
    In: Child's Nervous System, 2014, Vol.30(4), pp.689-697
    Description: Byline: Florian Baptist Freimann (1), Matthias Schulz (2), Hannes Haberl (2), Ulrich-Wilhelm Thomale (2) Keywords: Adjustable valves; Gravitational valves; Hydrocephalus; Intracranial pressure; Telemetry Abstract: Object The advances in shunt valve technology towards modern adjustable differential pressure (DP) valves and adjustable gravitational assisted valves result in an increasing complexity of therapeutical options. Modern telemetric intracranial pressure (ICP) sensors may be helpful in their application for diagnostic purposes in shunt therapy. We present our first experiences on telemetric ICP-guided valve adjustments in cases with the combination of an adjustable DP valve and adjustable gravitational unit. Methods Four consecutive cases were evaluated in a retrospective review who had received a proGAV adjustable, gravitational assisted DP valve with secondary in-line implantation of an adjustable shunt assistant (proSA), together with a telemetric ICP sensor (Neurovent-P-tel) between December 2010 and June 2012 in our institution. The measured ICP values and the corresponding valve adjustments were analyzed in correlation with the clinical course and the cranial imaging of the patients. Results No surgery-related complications were observed after implantation of the proSA and the telemetric ICP sensor additional to the proGAV. ICP values could actively be influenced by adjustments of the respective valve units. An increase of the position depending resistance of the proSA resulted in significant attenuated negative ICP values for the standing position, while adjustments of the proGAV could be detected not only in a supine position but also in a standing position. A clinical improvement could be achieved in all cases. Conclusion The combination of adjustability in the differential pressure valve and the gravitational unit reveals a complex combination which may be difficult to adapt only according to clinical information. Telemetric ICP-guided valve adjustments seem to be a promising tool as an objective measure according to different body positions. Further investigations are needed to select the patients for these costly implants. Author Affiliation: (1) Department of Neurosurgery, Charite - Universitatsmedizin Berlin, Berlin, Germany (2) Division of Pediatric Neurosurgery, Charite - Universitatsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany Article History: Registration Date: 12/11/2013 Received Date: 30/08/2013 Accepted Date: 11/11/2013 Online Date: 22/11/2013
    Keywords: Adjustable valves ; Gravitational valves ; Hydrocephalus ; Intracranial pressure ; Telemetry
    ISSN: 0256-7040
    E-ISSN: 1433-0350
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  • 9
    In: Dalton Transactions, Dalton Transactions, 2012, Vol.41(46), pp.14188-14196
    Description: The phosphides RE Ir 2 P 2 ( RE = LaNd, Sm) and arsenides RE Ir 2 As 2 ( RE = LaNd) were synthesized by a ceramic route via precursor compounds RE Ir 2 with phosphorus and arsenic, respectively. Well-shaped single crystals were obtained from lead and bismuth fluxes, respectively. The nine pnictides crystallize with the tetragonal CaBe 2 Ge 2 type structure, space group P 4/ nmm . The structures of CeIr 2 P 2 , SmIr 2 P 2 , LaIr 2 As 2 and CeIr 2 As 2 were refined from single crystal X-ray diffractometer data. The structures are composed of three-dimensional [Ir 2 P 2 ] and [Ir 2 As 2 ] networks in which the rare earth atoms fill cavities of coordination number 16 (8 P + 8 Ir). The phosphorus and arsenic atoms have tetrahedral and square pyramidal iridium coordination. Temperature dependent magnetic susceptibility measurements show intermediate cerium valence for CeIr 2 P 2 . The rare-earth and phosphorus local environments in LaIr 2 P 2 are characterized further by 139 La and 31 P single and double resonance solid state nuclear magnetic resonance (NMR) spectroscopy. Strong 31 P Knight shifts and extremely short spin-lattice relaxation times indicate that the bonding character of the phosphide species is strongly metallic. The two crystallographically distinct phosphorus sites are well-resolved in the 31 P magic-angle spinning (MAS) spectrum and also differ significantly with respect to their effective magnetic shielding anisotropies. Unambiguous site assignments are accomplished on the basis of homonuclear 31 P 31 P magnetic dipoledipole interactions, which can be measured in a site-resolved fashion in this compound using static 31 P spin echo decay spectroscopy. The highly symmetric La environment in LaIr 2 P 2 is characterized by a sharp 139 La MAS-NMR spectrum, revealing rather weak nuclear electric quadrupole coupling. Furthermore, a second local environment is detected, which is characterized by stronger quadrupolar coupling and similar dipolar coupling strength with 31 P as the regular site, according to 139 La{ 31 P} rotational echo double resonance (REDOR) NMR results. On the basis of these data we attribute this site to a La species next to a phosphorus vacancy. From the signal area of this resonance we deduce a composition LaIr 2 P 1.90 .
    Keywords: Joining ; Phosphides ; Single Crystals ; Solid State ; Phosphorus ; Nuclear Magnetic Resonance ; Rare Earth Metals ; Arsenides ; Processing Science (Wc) ; Miscellaneous Sciences (So) ; Analysis (MD) ; Chemical Analysis (Ep) ; Chemical Analysis (Ed) ; Chemical Analysis (EC);
    ISSN: 1477-9226
    E-ISSN: 1477-9234
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  • 10
    Language: English
    In: Child's Nervous System, 2013, Vol.29(3), pp.425-431
    Description: Byline: Ulrich-W Thomale (1,2), Anna F. Gebert (1), Hannes Haberl (1), Matthias Schulz (1) Keywords: Hydrocephalus; Pediatric; CSF shunt; Adjustable valves; Gravitational unit; Over drainage; Under drainage Abstract: Object Overdrainage is a chronic complication in shunted pediatric patients with hydrocephalus. The use of adjustability of differential pressure (DP) valves in combination with antisiphoning devices may help to overcome this sequela and may diminish the rate of possible shunt failures. The purpose of this retrospective study is to report our experience on shunt survival and infection rate with an adjustable DP valve with integrated gravitational unit in pediatric hydrocephalus. Methods The proGAV consists of an adjustable differential pressure (DP) valve and a gravitational unit. During the time period of July 2004 and December 2009, a total of 237 adjustable gravitational valves were used in 203 children (age, 6.5+-6.54 0--27 years). In the follow-up period, valve and shunt failures as well as rate of infection were recorded. Results Within the average follow-up time of 21.9+-10.3 months (range, 6--72 months), the valve survival rate was 83.8 %. The overall shunt survival rate including all necessary revisions was 64.3 %. Looking at the group of infants (〈1 year of age) within the cohort, the valve survival rate was 77.3 % and the shunt survival rate was 60.9 %. The overall infection rate was 4.6 %. Conclusion In a concept of avoiding chronic overdrainage by using the proGAV in hydrocephalic children, we observed a good rate of valve and shunt survival. Compared to previous reported series, we experienced the proGAV as a reliable tool for the treatment of pediatric hydrocephalus. Author Affiliation: (1) Pediatric Neurosurgery, Charite Universitatsmedizin Berlin, Berlin, Germany (2) Arbeitsbereich Padiatrische Neurochirurgie, Charite Universitatsmedizin, Campus Virchow Klinikum, Augustenburger Platz 1, Berlin, 13353, Germany Article History: Registration Date: 25/10/2012 Received Date: 05/06/2012 Accepted Date: 24/10/2012 Online Date: 08/11/2012
    Keywords: Hydrocephalus ; Pediatric ; CSF shunt ; Adjustable valves ; Gravitational unit ; Over drainage ; Under drainage
    ISSN: 0256-7040
    E-ISSN: 1433-0350
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