ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Beschreibung: The optical and resonance Raman spectra of the 2,2′: 6′,2″:6″,6-trioxytriphenyl-amine cation are measured and interpreted. This molecule contains two simultaneous types of coupling between three chromophores and two types of bridging atoms. The first and conventional coupling involves a single nitrogen bridge that couples all three aryl groups. The second is provided by the three oxygen atoms, each of which bridges two adjacent aryl groups. There are two bands in the visible region of the optical absorption spectrum; their assignment and the interpretation of the contributing orbitals and electronic states are described in terms of the neighboring orbital model that explains the effects of the two types of coupling. The bonding changes that take place in the excited electronic states are probed by resonance Raman spectroscopy intensities and analyzed using the time-dependent theory of resonance Raman spectroscopy. The optical absorption spectrum was fit using the measured vibrational frequencies and excited state distortions. The distortions correlate well with the bonding changes predicted by the neighboring orbital model. The resonance Raman data and neighboring orbital model analysis reveal that the two optical absorption bands correspond to charge transfers from aryl groups with different nodal structures in their pi orbitals. Copyright © 2012 John Wiley & Sons, Ltd. The three-chromophore cation (left) has a symmetric charge distribution in its ground state and three equivalent charge-bearing units in its lowest excited state. Coupling between the three units occurs through the central nitrogen and pair-wise through the oxygen. The effects of the coupling on the electronic and resonance Raman spectra are interpreted using the neighboring orbital model.

Print ISSN: 0894-3230

Digitale ISSN: 1099-1395

Thema: Chemie und Pharmazie , Physik

Publiziert von Wiley

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

3

Unbekannt

Perinuclear positioning of the inactive human cystic fibrosis gene depends on CTCF, A-type lamins and an active histone deacetylase (2012)

Joscha S. Muck, Karthikeyan Kandasamy, Andreas Englmann, Martin Günther, Daniele Zink

Wiley

In: Journal of Cellular Biochemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2012-04-16

Beschreibung: The nuclear positioning of mammalian genes often correlates with their functional state. For instance, the human cystic fibrosis transmembrane conductance regulator (CFTR) gene associates with the nuclear periphery in its inactive state, but occupies interior positions when active. It is not understood how nuclear gene positioning is determined. Here, we investigated trichostatin A (TSA)-induced repositioning of CFTR in order to address molecular mechanisms controlling gene positioning. Treatment with the histone deacetylase (HDAC) inhibitor TSA induced increased histone acetylation and CFTR repositioning towards the interior within 20 minutes. When CFTR localized in the nuclear interior (either after TSA treatment or when the gene was active) consistent histone H3 hyperacetylation was observed at a CTCF site close to the CFTR promoter. Knockdown experiments revealed that CTCF was essential for perinuclear CFTR positioning and both, CTCF knockdown as well as TSA treatment had similar and CFTR-specific effects on radial positioning. Furthermore, knockdown experiments revealed that also A-type lamins were required for the perinuclear positioning of CFTR. Together, the results showed that CTCF, A-type lamins and an active HDAC were essential for perinuclear positioning of CFTR and these components acted on a CTCF site adjacent to the CFTR promoter. The results are consistent with the idea that CTCF bound close to the CFTR promoter, A-type lamins and an active HDAC form a complex at the nuclear periphery, which becomes disrupted upon inhibition of the HDAC, leading to the observed release of CFTR. J. Cell. Biochem. © 2012 Wiley Periodicals, Inc.

Digitale ISSN: 0091-7419

Thema: Biologie , Chemie und Pharmazie , Medizin

Publiziert von Wiley

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

4

Unbekannt

Excited state mixed valence in a dual-bridged three-chromophore system (2012)

Marcelle Dibrelle; Ryan Hoekstra; Michael N. Weaver; Keiji Okada; Stephen F. Nelsen; Jeffrey I. Zink

Wiley

In: Journal of Physical Organic Chemistry

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2012-01-27

Beschreibung: The optical and resonance Raman spectra of the 2,2′: 6′,2″:6″,6-trioxytriphenyl-amine cation are measured and interpreted. This molecule contains two simultaneous types of coupling between three chromophores and two types of bridging atoms. The first and conventional coupling involves a single nitrogen bridge that couples all three aryl groups. The second is provided by the three oxygen atoms, each of which bridges two adjacent aryl groups. There are two bands in the visible region of the optical absorption spectrum; their assignment and the interpretation of the contributing orbitals and electronic states are described in terms of the neighboring orbital model that explains the effects of the two types of coupling. The bonding changes that take place in the excited electronic states are probed by resonance Raman spectroscopy intensities and analyzed using the time-dependent theory of resonance Raman spectroscopy. The optical absorption spectrum was fit using the measured vibrational frequencies and excited state distortions. The distortions correlate well with the bonding changes predicted by the neighboring orbital model. The resonance Raman data and neighboring orbital model analysis reveal that the two optical absorption bands correspond to charge transfers from aryl groups with different nodal structures in their pi orbitals. Copyright © 2012 John Wiley & Sons, Ltd. The three-chromophore cation (left) has a symmetric charge distribution in its ground state and three equivalent charge-bearing units in its lowest excited state. Coupling between the three units occurs through the central nitrogen and pair-wise through the oxygen. The effects of the coupling on the electronic and resonance Raman spectra are interpreted using the neighboring orbital model.

Print ISSN: 0894-3230

Digitale ISSN: 1099-1395

Thema: Chemie und Pharmazie , Physik

Publiziert von Wiley

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

5

Unbekannt

Stochastic temporal disaggregation of monthly precipitation for regional gridded data sets (2014)

Stephan Thober, Juliane Mai, Matthias Zink, Luis Samaniego

Wiley

In: Water Resources Research

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2014-10-10

Beschreibung: Weather generators are used for spatio-temporal downscaling of climate model outputs (e.g., precipitation and temperature) to investigate the impact of climate change on the hydrological cycle. In this study, a multiplicative random cascade model is proposed for the stochastic temporal disaggregation of monthly to daily precipitation fields, which is designed to be applicable to grids of any spatial resolution and extent. The proposed method uses stationary distribution functions that describe the partitioning of precipitation throughout multiple temporal scales (e.g., weekly and bi-weekly scale). Moreover, it explicitly considers the intensity and spatial covariance of precipitation in the disaggregation procedure, but requires no assumption about the temporal relationship and spatial isotropy of precipitation fields. A split sampling test is conducted on a high-resolution (i.e., 4×4 km 2 grid) daily precipitation data set over Germany (≈ 357 000 km 2 ) to assess the performance of the proposed method during future periods. The proposed method has proven to consistently reproduce distinctive location dependent precipitation distribution functions with biases less than 5% during both a calibration and evaluation period. Furthermore, extreme precipitation amounts and the spatial and temporal covariance of the generated fields are comparable to those of the observations. Consequently, the proposed temporal disaggregation approach satisfies the minimum conditions for a precipitation generator aiming at the assessment of hydrological response to climate change at regional and continental scales or for generating seamless predictions of hydrological variables.

Print ISSN: 0043-1397

Digitale ISSN: 1944-7973

Thema: Architektur, Bauingenieurwesen, Vermessung , Geographie

Publiziert von Wiley im Namen von American Geophysical Union (AGU).

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

6

Unbekannt

Advancing translational research (2011)

B. Bolon ; B. Altrock ; S. W. Barthold ; [weitere]

American Association for the Advancement of Science (AAAS)

In: Science. 331(6024): 1516-7. doi: 10.1126/science.331.6024.1516-b.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2011-03-26

Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bolon, Brad -- Altrock, Bruce -- Barthold, Stephen W -- Baumgarth, Nicole -- Besselsen, David -- Boivin, Gregory -- Boyd, Kelli L -- Brayton, Cory -- Cardiff, Robert D -- Couto, Suzana -- Eaton, Kathryn A -- Foreman, Oded -- Griffey, Stephen M -- La Perle, Krista -- Lairmore, Michael D -- Liu, Chen -- Meyerholz, David K -- Nikitin, Alexander Yu -- Schoeb, Trenton R -- Schwahn, Denise -- Sellers, Rani S -- Sundberg, John P -- Tolwani, Ravi -- Valli, Victor E -- Zink, M Christine -- U01 CA141582/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 2011 Mar 25;331(6024):1516-7. doi: 10.1126/science.331.6024.1516-b.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21436422" target="_blank"〉PubMed〈/a〉

Schlagwort(e): National Institutes of Health (U.S.)/*organization & administration ; Translational Medical Research/*organization & administration ; United States

Print ISSN: 0036-8075

Digitale ISSN: 1095-9203

Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik

Publiziert von American Association for the Advancement of Science (AAAS)

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

7

Unbekannt

The runaway instability in general relativistic accretion discs (2013)

Korobkin, O., Abdikamalov, E., Stergioulas, N., Schnetter, E., Zink, B., Rosswog, S., Ott, C. D.

Oxford University Press

In: Monthly Notices of the Royal Astronomical Society

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2013-04-03

Beschreibung: When an accretion disc falls prey to the runaway instability, a large portion of its mass is devoured by the black hole within a few dynamical times. Despite decades of effort, it is still unclear under what conditions such an instability can occur. The technically most advanced relativistic simulations to date were unable to find a clear sign for the onset of the instability. In this work, we present three-dimensional relativistic hydrodynamics simulations of accretion discs around black holes in dynamical space–time. We focus on the configurations that are expected to be particularly prone to the development of this instability. We demonstrate, for the first time, that the fully self-consistent general relativistic evolution does indeed produce a runaway instability.

Print ISSN: 0035-8711

Digitale ISSN: 1365-2966

Thema: Physik

Publiziert von Oxford University Press

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

8

Unbekannt

Passenger pigeon was not always super abundant [Evolution] (2014)

Hung, C.-M., Shaner, P.-J. L., Zink, R. M., Liu, W.-C., Chu, T.-C., Huang, W.-S., Li, S.-H.

National Academy of Sciences

In: PNAS - Proceedings of the National Academy of Sciences

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2014-07-23

Beschreibung: To assess the role of human disturbances in species’ extinction requires an understanding of the species population history before human impact. The passenger pigeon was once the most abundant bird in the world, with a population size estimated at 3–5 billion in the 1800s; its abrupt extinction in 1914 raises...

Print ISSN: 0027-8424

Digitale ISSN: 1091-6490

Thema: Biologie , Medizin , Allgemeine Naturwissenschaft

Publiziert von National Academy of Sciences

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

9

Unbekannt

Drug Release from Three-Dimensional Cubic Mesoporous Silica Nanoparticles Controlled by Nanoimpellers (2014)

Eunshil Choi, Jie Lu, Fuyuhiko Tamanoi, Jeffrey I. Zink

Wiley

In: Zeitschrift für Anorganische und Allgemeine Chemie

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2014-01-10

Beschreibung: Mesoporous silica nanoparticles with a cubic ( Ia 3 d ) pore structure are derivatized with light-activated nanoimpellers to control the release of loaded guest molecules under external photo-control. The nanoimpellers consist of azobenzene derivatives that are attached to the interiors of the three-dimensional interconnected pores, and undergo photoisomerization that results in dynamic wagging motions of the unbound termini and drives the expulsion of molecules from the pores. Stimulated release experiments monitored by fluorescence spectroscopy demonstrate that the nanoimpeller-functionalized MCM-48 particles are able to trap and release both hydrophilic and hydrophobic cargo molecules under external photocontrol in aqueous, non-aqueous, and intracellular environments.

Print ISSN: 0044-2313

Digitale ISSN: 1521-3749

Thema: Chemie und Pharmazie

Publiziert von Wiley

Permalink