Magnetic phase separation in ordered alloys

We present a lattice model to study the equilibrium phase diagram of ordered alloys with one magnetic component that exhibits a low temperature phase separation between paramagnetic and ferromagnetic phases. The model is constructed from the experimental facts observed in Cu3-xAlMnx and it includes coupling between configurational and magnetic degrees of freedom that are appropriate for reproducing the low temperature miscibility gap. The essential ingredient for the occurrence of such a coexistence region is the development of ferromagnetic order induced by the long-range atomic order of the magnetic component. A comparative study of both mean-field and Monte Carlo solutions is presented. Moreover, the model may enable the study of the structure of ferromagnetic domains embedded in the nonmagnetic matrix. This is relevant in relation to phenomena such as magnetoresistance and paramagnetism

Hysteresis in a system driven by either generalized force or displacement variables: martensitic phase transition in single-crystalline Cu-Zn-Al

We report on experiments aimed at comparing the hysteretic response of a Cu-Zn-Al single crystal undergoing a martensitic transition under strain-driven and stress-driven conditions. Strain-driven experiments were performed using a conventional tensile machine while a special device was designed to perform stress-driven experiments. Significant differences in the hysteresis loops were found. The strain-driven curves show reentrant behavior yield point which is not observed in the stress-driven case. The dissipated energy in the stress-driven curves is larger than in the strain-driven ones. Results from recently proposed models qualitatively agree with experiments.

A nucleosome-dependent static loop potentiates estrogen-regulated transcription from the Xenopus vitellogenin B1 promoter in vitro.

We describe the transcriptional potentiation in estrogen responsive transcription extracts of the Xenopus vitellogenin B1 gene promoter through the formation of a positioned nucleosome. Nuclease digestion and hydroxyl radical cleavage indicate that strong, DNA sequence-directed positioning of a nucleosome occurs between -300 and -140 relative to the start site of transcription. Deletion of this DNA sequence abolishes the potentiation of transcription due to nucleosome assembly. The wrapping of DNA around the histone core of the nucleosome positioned between -300 and -140 creates a static loop in which distal estrogen receptor binding sites are brought close to proximal promoter elements. This might facilitate interactions between the trans-acting factors themselves and/or RNA polymerase. Such a nucleosome provides an example of how chromatin structure might have a positive effect on the transcription process.

Monitoring tumor antigen specific T-cell responses in cancer patients and phase I clinical trials of peptide-based vaccination.

Numerous phase I and II clinical trials testing the safety and immunogenicity of various peptide vaccine formulations based on CTL-defined tumor antigens in cancer patients have been reported during the last 7 years. While specific T-cell responses can be detected in a variable fraction of immunized patients, an even smaller but significant fraction of these patients have objective tumor responses. Efficient therapeutic vaccination should aim at boosting naturally occurring antitumor T- and B-cell responses and at sustaining a large number of tumor antigen specific and fully functional effector T cells at tumor sites. Recent progress in our ability to quantitatively and qualitatively monitor tumor antigen specific CD8 T-cell responses will greatly help in making rapid progress in this field.

Random-field Potts model with dipolarlike interactions: Hysteresis avalanches and microstructure

A model for the study of hysteresis and avalanches in a first-order phase transition from a single variant phase to a multivariant phase is presented. The model is based on a modification of the random-field Potts model with metastable dynamics by adding a dipolar interaction term truncated at nearest neighbors. We focus our study on hysteresis loop properties, on the three-dimensional microstructure formation, and on avalanche statistics.

PRECISION V: Randomisierte Phase II-Studie mit Drug Eluting Beads (DEB) zur Behandlung des hepatozelluläre Karzinoms (HCC) mittels transarterieller Chemoemblisation [PRECISION V: Randomized Phase II-Study with Drug Eluting Beads (DEB) for the Treatment of Hepatocellular cancer (HCC) using transarterial Chemoemblisation.]

Zielsetzung: Vergleich von Drug Eluting Bead (DEB)-TACE mit konventioneller TACE bei der Behandlung von ,,intermediate stage-HCC bei Patienten mit Zirrhose. Material und Methodik: 212 Patienten (185 ♂, 27 ♀; mittleres Alter, 67 Jahre) mit Child-Pugh A oder B Leberzirrhose und großem und/oder multinodulärem, irresektablen HCC wurden randomisiert, um das Therapieansprechen nach der Behandlung mit DEB (DC Bead; Biocompatibles, UK) beladen mit Doxorubicin oder konventioneller TACE mit Doxorubicin zu vergleichen. Die Randomisierung wurde nach Child-Pugh Status (A oder B), Performance Status (ECOG 0 oder 1), bilobärer Erkrankung (ja/nein) und frühere kurative Behandlung (ja/nein) stratifiziert. Der primäre Studienendpunkt war das 6-Monats-Tumoransprechen. Eine unabhängige verblindete MRT-Studie wurde durchgeführt, um das Tumoransprechen nach den RECIST Kriterien zu beurteilen. Ergebnisse: DEB-TACE mit Doxorubicin zeigte eine höhere Rate an komplettem Tumoransprechen, objektivem Ansprechen und Tumorkontrolle im Vergleich zur konventionellen TACE (27% vs 22%; 52% vs 44%; and 63% vs 52%; P>0.05). Patienten mit Child-Pugh B Zirrhose, ECOG 1 Performance Status, bilobärer Erkrankung und Rezidiven nach kurativer Behandlung zeigte einen signifikanten Anstieg des objektiven Ansprechens (p = 0.038) im Vergleich zur Kontrollgruppe. Bei Patienten, die mit DEB-TACE behandelt wurden, konnte eine deutliche Reduktion der gravierenden Lebertoxizität erreicht werden. Die Doxorubicin-Nebenwirkungsrate war in der DEB-TACE Gruppe deutlich geringer (p = 0.0001) als in der konventionellen TACEGruppe. Schlussfolgerung: DEB-TACE mit Doxorubicin ist sicher und effektiv in der Behandlung von ,,intermediate-stage HCC und bietet einen signifikanten Vorteil bei Patienten mit fortgeschrittener Erkrankung.

Safety and Mobility Impacts of Winter Weather – Phase I, August 2011

Highway agencies spend millions of dollars to ensure safe and efficient winter travel. However, the effectiveness of winter weather maintenance practices on safety and mobility are somewhat difficult to quantify. Phase I of this project investigated opportunities for improving traffic safety on state-maintained roads in Iowa during winter weather conditions. The primary objective was to develop several preliminary means for the Iowa Department of Transportation (DOT) to identify locations of possible interest systematically with respect to winter weather-related safety performance based on crash history. Specifically, metrics were developed to assist in identifying possible habitual, winter weather-related crash sites on state-maintained rural highways in Iowa. In addition, the current state of practice, for both domestic and international highway agency practices, regarding integration of traffic safety- and mobility-related data in winter maintenance activities and performance measures were investigated. This investigation also included previous research efforts. Finally, a preliminary work plan, focusing on systematic use of safety-related data in support of winter maintenance activities and site evaluation, was prepared.

Liquid-gas phase transition in nuclear matter from realistic many-body approaches

The existence of a liquid-gas phase transition for hot nuclear systems at subsaturation densities is a well-established prediction of finite-temperature nuclear many-body theory. In this paper, we discuss for the first time the properties of such a phase transition for homogeneous nuclear matter within the self-consistent Green's function approach. We find a substantial decrease of the critical temperature with respect to the Brueckner-Hartree-Fock approximation. Even within the same approximation, the use of two different realistic nucleon-nucleon interactions gives rise to large differences in the properties of the critical point.