Properties of an ionization spectrometer exposed to 10, 20.5, and 28 GeV/c machine accelerated protons

Properties of ionization spectrometer exposed to 10, 20.5, and 28 GeV/c synchrotron accelerated proton

Zeno Dynamics in Quantum Statistical Mechanics

We study the quantum Zeno effect in quantum statistical mechanics within the operator algebraic framework. We formulate a condition for the appearance of the effect in W*-dynamical systems, in terms of the short-time behaviour of the dynamics. Examples of quantum spin systems show that this condition can be effectively applied to quantum statistical mechanical models. Further, we derive an explicit form of the Zeno generator, and use it to construct Gibbs equilibrium states for the Zeno dynamics. As a concrete example, we consider the X-Y model, for which we show that a frequent measurement at a microscopic level, e.g. a single lattice site, can produce a macroscopic effect in changing the global equilibrium.Comment: 15 pages, AMSLaTeX; typos corrected, references updated and added, acknowledgements added, style polished; revised version contains corrections from published corrigend

The tumour-Clostridium phenomenon: 50 years of developmental research

The tumour-Clostridium phenomenon describes the specific affinity of spore forming anaerobes to tumour growth. The discovery of strictly intratumoral tetanus toxicoinfections in tumour-bearing mice after intravenous spore administration gave the impulse to search for non-toxic clostridial isolates with tumour-selective properties for clostridial biotherapy, i.e. oncolysis, as well as serologic tumour diagnostics without any toxic side-effects. Systematic studies of the oncolytic process and its variables on diverse experimental tumours and laboratory animals revealed that tumour liquefaction, converting necrotic tumour parts to putrid abscesses filled with masses of clostridial forms, stops sharply at the viable rim of the blood-supplied tumour tissue. Similar results were observed in clinical trials, particular of gliomas. Before oncolysis is initiated, the first stage of clostridial multi-plication in the vascularized tissue is inducing a humoural immune response, preceded by phagocytic activity. The majority of tumour-bearing laboratory and domestic animals, so far tested serologically, clinical cancer patients as well, responded with anti-rod antibodies and, independently, anti-spore antibodies. Oncolytic and non-oncolytic Clostridia were equally immunogenic. During the early, immunizing period of clostridial proliferation, analytical tumour-tetanus experiments were focused on potential relations between tumour growth kinetics and rod proliferation. Based on realistic growth models and target principles, computer simulations could reproduce the results, i.e. cumulative curves of tetanus lethality in groups of mice. Thus, crucial assumptions of the mathematical model were ex post confirmed by further experiments. Our working hypothesis concentrates on temporally hypoxic micro-niches close to a pre-mitotic cell with enhanced oxygen demand which can be utilized by anaerobes (randomly) located there. As early immune reactions to clostridial antigens via phagocytosis and humoural immune response will do without invasion in necrobiotic avascular tumour areas, the pacemaker model of tumour-Clostridium interplay extends the scope of genetically engineered Clostridia to early treatment of metastases. Thus, novel concepts, such as 'Clostridia-directed enzyme prodrug-therapy' and 'Combined bacteriolytic therapy', together with immune activation, can come into play

2-Aminoterephthalic acid dimethyl ester

Single crystals of the title compound, C10H11NO4, an inter­mediate in the industrial synthesis of yellow azo pigments, were obtained from the industrial production. The mol­ecules crystallize as centrosymmetic dimers connected by two symmetry-related N—H⋯O=C hydrogen bonds. Each mol­ecule also contains an intra­molecular N—H⋯O=C hydrogen bond. The dimers form stacks along the a-axis direction. Neighbouring stacks are arranged into a herringbone structure

On the electronic structure of the charge-ordered phase in epitaxial and polycrystalline La1-xCaxMnO3 (x = 0.55, 0.67) perovskite manganites

In this work the charge transport properties of charge ordered (CO) La1-xCaxMnO3 (LCMO) (x= 0.55, 0.67) epitaxial thin films and polycrystals are discussed following the recent controversy of localised electron states vs. weakly or de- localised charge density wave (CDW) states in CO manganites. The transport properties were investigated by current vs. voltage, direct current resistivity vs. temperature, local activation energy vs. temperature, magnetoresistance and admittance spectroscopy measurements, which all indicated a localised electronic structure in the single CO phase. Delocalised charge anomalies observed previously may be restricted to phase separated materials.Comment: Physical Review B, to be publishe

Measurement of the Permanent Electric Dipole Moment of the 129^{129}Xe Atom

We report on a new measurement of the CP-violating permanent Electric Dipole Moment (EDM) of the neutral $^{129}$Xe atom. Our experimental approach is based on the detection of the free precession of co-located nuclear spin-polarized $^3$He and $^{129}$Xe samples. The EDM measurement sensitivity benefits strongly from long spin coherence times of several hours achieved in diluted gases and homogeneous weak magnetic fields of about 400~nT. A finite EDM is indicated by a change in the precession frequency, as an electric field is periodically reversed with respect to the magnetic guiding field. Our result, $\left(-4.7\pm6.4\right)\cdot 10^{-28}$ ecm, is consistent with zero and is used to place a new upper limit on the $^{129}$Xe EDM: $|d_\text{Xe}|<1.5 \cdot 10^{-27}$ ecm (95% C.L.). We also discuss the implications of this result for various CP-violating observables as they relate to theories of physics beyond the standard model