1,682 research outputs found
Perforatationstrauma im Gesichtsschädel. Eine ungewöhnliche Verletzung beim Skifahren
Facial perforation injuries are very rare. We describe a case of a 48-year-old man who sustained a perforation trauma from an 11 cm long wooden tree branch in the middle of the face in a skiing accident. He suffered from additional injuries, such as fractures of the ribs and hand, but was neurologically without pathologic findings and was cardiopulmonary stable.The branch penetrated the head from the sinus maxillaris through the maxilla just missing the internal and external carotid arteries and ending just short of the cervical vertebra. The patient was transported to a center for oral and maxillofacial surgery and underwent several operations.He could return to his normal social and professional life 8 months after the accident
Three-tangle for mixtures of generalized GHZ and generalized W states
We give a complete solution for the three-tangle of mixed three-qubit states
composed of a generalized GHZ state, a|000>+b|111>, and a generalized W state,
c|001>+d|010>+f|100>. Using the methods introduced by Lohmayer et al. we
provide explicit expressions for the mixed-state three-tangle and the
corresponding optimal decompositions for this more general case. Moreover, as a
special case we obtain a general solution for a family of states consisting of
a generalized GHZ state and an orthogonal product state
Algebraic invariants of five qubits
The Hilbert series of the algebra of polynomial invariants of pure states of
five qubits is obtained, and the simplest invariants are computed.Comment: 4 pages, revtex. Short discussion of quant-ph/0506073 include
Robustness of adiabatic passage trough a quantum phase transition
We analyze the crossing of a quantum critical point based on exact results
for the transverse XY model. In dependence of the change rate of the driving
field, the evolution of the ground state is studied while the transverse
magnetic field is tuned through the critical point with a linear ramping. The
excitation probability is obtained exactly and is compared to previous studies
and to the Landau-Zener formula, a long time solution for non-adiabatic
transitions in two-level systems. The exact time dependence of the excitations
density in the system allows to identify the adiabatic and diabatic regions
during the sweep and to study the mesoscopic fluctuations of the excitations.
The effect of white noise is investigated, where the critical point transmutes
into a non-hermitian ``degenerate region''. Besides an overall increase of the
excitations during and at the end of the sweep, the most destructive effect of
the noise is the decay of the state purity that is enhanced by the passage
through the degenerate region.Comment: 16 pages, 15 figure
Membrane mediated toppling mechanism of the folate energy coupling factor transporter
Energy coupling factor (ECF) transporters are responsible for the uptake of micronutrients in bacteria and archaea. They consist of an integral membrane unit, the S-component, and a tripartite ECF module. It has been proposed that the S-component mediates the substrate transport by toppling over in the membrane when docking onto an ECF module. Here, we present multi-scale molecular dynamics simulations and in vitro experiments to study the molecular toppling mechanism of the S-component of a folate-specific ECF transporter. Simulations reveal a strong bending of the membrane around the ECF module that provides a driving force for toppling of the S-component. The stability of the toppled state depends on the presence of non-bilayer forming lipids, as confirmed by folate transport activity mea- surements. Together, our data provide evidence for a lipid-dependent toppling-based mechanism for the folate-specific ECF transporter, a mechanism that might apply to other ECF transporters
Vibrational Spectra of a Mechanosensitive Channel
We report the simulated vibrational spectra of a mechanosensitive membrane channel in different gating states. Our results show that while linear absorption is insensitive to structural differences, linear dichroism and sum-frequency generation spectroscopies are sensitive to the orientation of the transmembrane helices, which is changing during the opening process. Linear dichroism cannot distinguish an intermediate structure from the closed structure, but sum-frequency generation can. In addition, we find that two-dimensional infrared spectroscopy can be used to distinguish all three investigated gating states of the mechanosensitive membrane channel.
Quantum algorithms for Josephson networks
We analyze possible implementations of quantum algorithms in a system of
(macroscopic) Josephson charge qubits. System layout and parameters to realize
the Deutsch algorithm with up to three qubits are provided. Special attention
is paid to the necessity of entangled states in the various implementations.
Further, we demonstrate explicitely that the gates to implement the
Bernstein-Vazirani algorithm can be realized by using a system of uncoupled
qubits
The New HZB X Ray Microscopy Beamline U41 PGM1 XM at BESSY II
At the BESSY II electron storage ring running by the Helmholtz Zentrum Berlin HZB a transmission soft X ray microscope TXM is operated very successfully for both tomographic imaging of cells [1,2] and for NEXAFS studies in materials science [3 5]. Here, we present the setup of a newly designed beamline Fig. 1 that will significantly enhance the performance of the HZB TXM. Faster data acquisition over the whole accessible photon energy range together with a possible extension into the tender X ray range is given. Furthermore, within the photon energy tuning range, two new important absorption edges, namely sulfur and phosphorus, will become accessible for element specific 3D imaging, in addition to those already available, e.g. at carbon, calcium, titanium and oxygen. Another advantage of this new beamline is that phase contrast X ray microscopy for thicker specimens will become possible in the tender X ray photon energy rang
Charge Transport in Voltage-Biased Superconducting Single-Electron Transistors
Charge is transported through superconducting SSS single-electron transistors
at finite bias voltages by a combination of coherent Cooper-pair tunneling and
quasiparticle tunneling. At low transport voltages the effect of an ``odd''
quasiparticle in the island leads to a -periodic dependence of the current
on the gate charge. We evaluate the characteristic in the framework of a
model which accounts for these effects as well as for the influence of the
electromagnetic environment. The good agreement between our model calculation
and experimental results demonstrates the importance of coherent Cooper-pair
tunneling and parity effects.Comment: RevTeX, 12 pages, 4 figure
The relationship between quality of life (EORTC QLQ-C30) and survival in patients with gastro-oesopohageal cancer
It remains unclear whether any aspect of quality of life has a role in predicting survival in an unselected cohort of patients with gastro-oesophageal cancer. Therefore the aim of the present study was to examine the relationship between quality of life (EORTC QLQ-C30), clinico-pathological characteristics and survival in patients with gastro-oesophageal cancer. Patients presenting with gastric or oesophageal cancer, staged using the UICC tumour node metastasis (TNM) classification and who received either potentially curative surgery or palliative treatment between November 1997 and December 2002 (n=152) participated in a quality of life study, using the EORTC QLQ-C30 core questionnaire. On univariate analysis, age (P < 0.01), tumour length (P < 0.0001), TNM stage (P<0.0001), weight loss (P<0.0001), dysphagia score (P<0.001), performance status (P<0.1) and treatment (P<0.0001) were significantly associated with cancer-specific survival. EORTC QLQ-C30, physical functioning (P<0.0001), role functioning (P<0.001), cognitive functioning (P<0.01), social functioning (P<0.0001), global quality of life (P<0.0001), fatigue (P<0.0001), nausea/vomiting (P<0.01), pain (P<0.001), dyspnoea (P<0.0001), appetite loss (P<0.0001) and constipation (P<0.05) were also significantly associated with cancer-specific survival. On multivariate survival analysis, tumour stage (P<0.0001), treatment (P<0.001) and appetite loss (P<0.0001) were significant independent predictors of cancer-specific survival. The present study highlights the importance of quality of life (EORTC QLQ-C30) measures, in particular appetite loss, as a prognostic factor in these patients
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