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991.
Tetyana Beryozkina Dr. Ksenia Boyko Natalya Khanduyeva Volodymyr Senkovskyy Dr. Marta Horecha Ulrich Oertel Dr. Frank Simon Dr. Manfred Stamm Prof. Anton Kiriy Dr. 《Angewandte Chemie (International ed. in English)》2009,48(15):2695-2698
Graft work : The first surface‐initiated and site‐specific palladium‐catalyzed Suzuki polycondensation that allows selective grafting and patterning of semiconducting and emissive poly[9,9‐bis(2‐ethylhexyl)fluorene] ( 1 ) at room temperature is developed (see scheme). The pattering is demonstrated by AFM (see image).
992.
Simon Reitz Menekse Cebi Philipp Reiß Gregor Studnik Uwe Linne Ulrich Koert Prof. Dr. Lars‐Oliver Essen Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4853-4857
The attachment of modulators to a trimeric porin ion channel was investigated (see picture of the trimer with a crown ether modulator (orange)). The interplay of modulator and protein is essential for the conformational heterogeneity of the hybrid channel. Single‐site attachment in large pores is not sufficient to change the electrophysiological characteristics of the pores—such change requires additional noncovalent interactions or second‐site attachments.
993.
Lianbing Zhang Avinash J. Patil Dr. Le Li Angelika Schierhorn Dr. Stephen Mann Prof. Ulrich Gösele Prof. Mato Knez Dr. 《Angewandte Chemie (International ed. in English)》2009,48(27):4982-4985
New uses for ALD : By applying standard metal oxide atomic layer deposition (ALD) to two types of porphyrins, site‐specific chemical infiltration of substrate molecules is achieved: Diethylzinc can diffuse into the interior of porphyrin supramolecular structures and induce metalation of the porphyrin molecules from the vapor phase. A=Ph, p‐HO3SC6H4.
994.
Christian M. Stegmann Daniel Seeliger Dr. George M. Sheldrick Prof. Dr. Bert L. de Groot Dr. Markus C. Wahl Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(28):5207-5210
Water molecules doing time : Atomic‐resolution crystal structures of the PPIase domain of cyclophilin G, alone and in complex with cyclosporin A, and together with MD simulations and calorimetry, reveal how trapped water molecules influence the thermodynamic profile of a protein–ligand interaction.
995.
Andreas Winter Dr. Christian Friebe Manuela Chiper Dr. Ulrich S. Schubert Prof. Dr. Martin Presselt Benjamin Dietzek Dr. Michael Schmitt Dr. Jürgen Popp Prof. Dr. 《Chemphyschem》2009,10(5):787-798
Leading light : A series of zinc(II) bis‐terpyridine complexes (see picture) is investigated by means of DFT calculations combined with Bader's quantum theory of atoms in molecules. Raman spectroscopy experiments and studies of the electro‐optical properties of the complexes in solution and the solid state are also performed to examine their potential as new emissive materials in light‐emitting devices.
996.
Jörg Votteler Elena Iavnilovitch Orit Fingrut Vivian Shemesh Daniel Taglicht Omri Erez Stefan Sörgel Torsten Walther Norbert Bannert Ulrich Schubert Yuval Reiss 《BMC biochemistry》2009,10(1):1-14
Background
The ALG2-interacting protein X (ALIX)/AIP1 is an adaptor protein with multiple functions in intracellular protein trafficking that plays a central role in the biogenesis of enveloped viruses. The ubiquitin E3-ligase POSH (plenty of SH3) augments HIV-1 egress by facilitating the transport of Gag to the cell membrane. Recently, it was reported, that POSH interacts with ALIX and thereby enhances ALIX mediated phenotypes in Drosophila.Results
In this study we identified ALIX as a POSH ubiquitination substrate in human cells: POSH induces the ubiquitination of ALIX that is modified on several lysine residues in vivo and in vitro. This ubiquitination does not destabilize ALIX, suggesting a regulatory function. As it is well established that ALIX rescues virus release of L-domain mutant HIV-1, HIV-1ΔPTAP, we demonstrated that wild type POSH, but not an ubiquitination inactive RING finger mutant (POSHV14A), substantially enhances ALIX-mediated release of infectious virions derived from HIV-1ΔPTAP L-domain mutant (YPXnL-dependent HIV-1). In further agreement with the idea of a cooperative function of POSH and ALIX, mutating the YPXnL-ALIX binding site in Gag completely abrogated augmentation of virus release by overexpression of POSH. However, the effect of the POSH-mediated ubiquitination appears to be auxiliary, but not necessary, as silencing of POSH by RNAi does not disturb ALIX-augmentation of virus release.Conclusion
Thus, the cumulative results identified ALIX as an ubiquitination substrate of POSH and indicate that POSH and ALIX cooperate to facilitate efficient virus release. However, while ALIX is obligatory for the release of YPXnL-dependent HIV-1, POSH, albeit rate-limiting, may be functionally interchangeable. 相似文献997.
Point-of-care testing (POCT) in patients with ischemic heart disease is driven by the time-critical need for fast, specific,
and accurate results to initiate therapy instantly. According to current guidelines, the results of the cardiac marker testing
should be available to the physician within 30 min (“vein-to-brain” time) to initiate therapy within 60–90 min (“door-to-needle”
time) after the patient has arrived at the emergency room or intensive care unit. This article reviews the current efforts
to meet this goal (1) by implementing POCT of established biochemical markers such as cardiac troponins, creatine kinase MB,
and myoglobin, in accelerated diagnosis and management workflow schemes, (2) by improving current POCT methods to obtain more
accurate, more specific, and even faster tests through the integration of optical and electrochemical sensor technology, and
(3) by identifying new markers for the very early and sensitive detection of myocardial ischemia and necrosis. Furthermore,
the specific requirements for cardiac POCT in regard to analytical performance, comparability, and diagnostic sensitivity/specificity
are discussed. For the future, the integration of new immunooptical and electrochemical chip technology might speed up diagnosis
even further. However, every new development will have to meet the stringent method validation criteria set for corresponding
central laboratory testing. 相似文献
998.
Christoph Logé Alexander Bornschlegl Ulrich Boesl 《Analytical and bioanalytical chemistry》2009,395(6):1631-1639
Circular dichroism in ion yield has promising new potentials for chiral analysis. Our progress of its development is described
here. Circular dichroism in ion yield is achieved by resonance-enhanced multiphoton ionization. The feasibility of circular
dichroism spectroscopy and quantitative determination of circular dichroism by this method is demonstrated. Several excitation
schemes have been applied using different types of lasers, which vary in wavelength and repetition rate. Progress to improve
the statistical error and thus the lower limit of measurable circular dichroism is described. This is achieved by adding achiral
compounds or racemic mixtures of chiral compounds to the sample gas as reference substances and ionizing them by the same
laser pulse. Therefore, in the mass spectrum of every single laser pulse, ion signals of sample and reference species appear
both being subject to the same kind of instrumental fluctuations (in particular of laser pulse energy). In another approach,
a laser repetition rate of 200 Hz allowed averaging of large numbers of laser pulses.
相似文献
999.
This paper describes a specific local search approach to solve a problem arising in logistics which we prove to be NP-hard. The problem is a complex scheduling or vehicle routing problem where we have to schedule the tours of concrete mixer vehicles over a working day from concrete-producing depots to concrete-demanding customers and vice versa. We give a general mixed integer programming model which is too hard to solve for state of the art mixed integer programming optimizers in the case of the usually huge problem instances coming from practice. Therefore we present a certain local search approach to be able to handle huge practical problem instances. 相似文献
1000.
We consider a stochastic control problem over an infinite horizon where the state process is influenced by an unobservable
environment process. In particular, the Hidden-Markov-model and the Bayesian model are included. This model under partial
information is transformed into an equivalent one with complete information by using the well-known filter technique. In particular,
the optimal controls and the value functions of the original and the transformed problem are the same. An explicit representation
of the filter process which is a piecewise-deterministic process, is also given. Then we propose two solution techniques for
the transformed model. First, a generalized verification technique (with a generalized Hamilton–Jacobi–Bellman equation) is
formulated where the strict differentiability of the value function is weaken to local Lipschitz continuity. Second, we present
a discrete-time Markovian decision model by which we are able to compute an optimal control of our given problem. In this
context we are also able to state a general existence result for optimal controls. The power of both solution techniques is
finally demonstrated for a parallel queueing model with unknown service rates. In particular, the filter process is discussed
in detail, the value function is explicitly computed and the optimal control is completely characterized in the symmetric
case. 相似文献