Observation of Macroscopic Structural Fluctuations in bcc Solid 4He

We report neutron diffraction studies of low density bcc and hcp solid 4He. In the bcc phase, we observed a continuous dynamical behaviour involving macroscopic structural changes of the solid. The dynamical behaviour takes place in a cell full of solid, and therefore represents a solidsolid transformation. The structural changes are consistent with a gradual rotation of macroscopic grains separated by low angle grain boundaries. We suggest that these changes are triggered by random momentary vibrations of the experimental system. An analysis of Laue diffraction patterns indicates that in some cases these structural changes, once initiated by a momentary impulse, seem to proceed at a constant rate over times approaching an hour. The energy associated with these macroscopic changes appears to be on the order of kT. Under similar conditions (temperature and pressure), these effects were absent in the hcp phase.Comment: 14 pages, 6 figure, accepted for PR

Stationary quantum Markov process for the Wigner function

As a stochastic model for quantum mechanics we present a stationary quantum Markov process for the time evolution of the Wigner function on a lattice phase space Z_N x Z_N with N odd. By introducing a phase factor extension to the phase space, each particle can be treated independently. This is an improvement on earlier methods that require the whole distribution function to determine the evolution of a constituent particle. The process has branching and vanishing points, though a finite time interval can be maintained between the branchings. The procedure to perform a simulation using the process is presented.Comment: 12 pages, no figures; replaced with version accepted for publication in J. Phys. A, title changed, an example adde

Existence of the Wigner function with correct marginal distributions along tilted lines on a lattice

In order to determine the Wigner function uniquely, we introduce a new condition which ensures that the Wigner function has correct marginal distributions along tilted lines. For a system in $N$ dimensional Hilbert space, whose "phase space" is a lattice with $N^2$ sites, we get different results depending on whether $N$ is odd or even. Under the new condition, the Wigner function is determined if $N$ is an odd number, but it does not exist if $N$ is even.Comment: 18 page

Wigner Functions on a Lattice

The Wigner functions on the one dimensional lattice are studied. Contrary to the previous claim in literature, Wigner functions exist on the lattice with any number of sites, whether it is even or odd. There are infinitely many solutions satisfying the conditions which reasonable Wigner functions should respect. After presenting a heuristic method to obtain Wigner functions, we give the general form of the solutions. Quantum mechanical expectation values in terms of Wigner functions are also discussed.Comment: 11 pages, no figures, REVTE

Spin-lattice instability to a fractional magnetization state in the spinel HgCr2O4

Magnetic systems are fertile ground for the emergence of exotic states when the magnetic interactions cannot be satisfied simultaneously due to the topology of the lattice - a situation known as geometrical frustration. Spinels, AB2O4, can realize the most highly frustrated network of corner-sharing tetrahedra. Several novel states have been discovered in spinels, such as composite spin clusters and novel charge-ordered states. Here we use neutron and synchrotron X-ray scattering to characterize the fractional magnetization state of HgCr2O4 under an external magnetic field, H. When the field is applied in its Neel ground state, a phase transition occurs at H ~ 10 Tesla at which each tetrahedron changes from a canted Neel state to a fractional spin state with the total spin, Stet, of S/2 and the lattice undergoes orthorhombic to cubic symmetry change. Our results provide the microscopic one-to-one correspondence between the spin state and the lattice distortion

Anticancer properties of propofol-docosahexaenoate and propofol-eicosapentaenoate on breast cancer cells

INTRODUCTION: Epidemiological evidence strongly links fish oil, which is rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), with low incidences of several types of cancer. The inhibitory effects of omega-3 polyunsaturated fatty acids on cancer development and progression are supported by studies with cultured cells and animal models. Propofol (2,6-diisopropylphenol) is the most extensively used general anesthetic–sedative agent employed today and is nontoxic to humans at high levels (50 μg/ml). Clinically relevant concentrations of propofol (3 to 8 μg/ml; 20 to 50 μM) have also been reported to have anticancer activities. The present study describes the synthesis, purification, characterization and evaluation of two novel anticancer conjugates, propofol-docosahexaenoate (propofol-DHA) and propofol-eicosapentaenoate (propofol-EPA). METHODS: The conjugates linking an omega-3 fatty acid, either DHA or EPA, with propofol were synthesized and tested for their effects on migration, adhesion and apoptosis on MDA-MB-231 breast cancer cells. RESULTS: At low concentrations (25 μM), DHA, EPA or propofol alone or in combination had minimal effect on cell adhesion to vitronectin, cell migration against serum and the induction of apoptosis (only 5 to 15% of the cells became apoptotic). In contrast, the propofol-DHA or propofol-EPA conjugates significantly inhibited cell adhesion (15 to 30%) and migration (about 50%) and induced apoptosis (about 40%) in breast cancer cells. CONCLUSION: These results suggest that the novel propofol-DHA and propofol-EPA conjugates reported here may be useful for the treatment of breast cancer

Keratinocyte Secretion of Cyclophilin B via the Constitutive Pathway Is Regulated through Its Cyclosporin-Binding Site

Cyclophilin B (CypB) is an endoplasmic reticulum (ER)-resident member of the cyclophilin family of proteins that bind cyclosporin A (CsA). We report that as in other cell types, CypB trafficked from the ER and was secreted by keratinocytes into the media in response to CsA. Concentrations as low as 1 p of CsA induced secretion of CypB. Using brefeldin A, we showed that CypB is secreted from keratinocytes via the constitutive secretory pathway. We defined that substitution of tryptophan residue 128 in the CsA-binding site of CypB with alanine resulted in dissociation of CypBW128A-green fluorescent protein (GFP) from the ER. Photobleaching studies revealed a significant reduction in the diffusible mobility of CypBW128A-GFP compared with CypBWT-GFP, consistent with redistribution of CypBW128A-GFP into secretory vesicles disconnected from the ER/Golgi network. Furthermore, CsA significantly decreased the mobility of CypBWT-GFP but not CypBW128A-GFP. These studies demonstrate that therapeutically relevant concentrations of CsA regulate secretion of CypB by keratinocytes, and that a key residue within the CsA-binding site of CypB controls retention of CypB within the ER and regulates entry into the secretory pathway. As keratinocytes express CypB receptors (CD147) and CypB exhibits chemotactic properties, these data have implications for the therapeutic effects of CsA in inflammatory skin disease

Fatigue of Yttria-Stabilized Zirconia: II, Crack Propagation, Fatigue Striations, and Short-Crack Behavior

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65604/1/j.1151-2916.1991.tb04089.x.pd

Markedly improved outcomes and acceptable toxicity in adolescents and young adults with acute lymphoblastic leukemia following treatment with a pediatric protocol: a phase II study by the Japan Adult Leukemia Study Group

The superiority of the pediatric protocol for adolescents with acute lymphoblastic leukemia (ALL) has already been demonstrated, however, its efficacy in young adults remains unclear. The ALL202-U protocol was conducted to examine the efficacy and feasibility of a pediatric protocol in adolescents and young adults (AYAs) with BCR\u27ABL-negative ALL. Patients aged 15\u2724 years (n = 139) were treated with the same protocol used for pediatric B-ALL. The primary objective of this study was to assess the disease-free survival (DFS) rate and its secondary aims were to assess toxicity, the complete remission (CR) rate and the overall survival (OS) rate. The CR rate was 94%. The 5-year DFS and OS rates were 67% (95% confidence interval (CI) 58\u2775%) and 73% (95% CI 64\u2780%), respectively. Severe adverse events were observed at a frequency that was similar to or lower than that in children treated with the same protocol. Only insufficient maintenance therapy significantly worsened the DFS (hazard ratio 5.60, Po0.001).These results indicate that this protocol may be a feasible and highly effective treatment for AYA with BCR\u27ABL-negative ALL

Functional Relationship between Protein Disulfide Isomerase Family Members during the Oxidative Folding of Human Secretory Proteins

We systematically depleted PDI family members and show that whereas ERp72 and P5 contributed minimally to oxidative protein folding, PDI and ERp57 were the predominant catalysts. Depletion of PDI or ERp57 alone modestly delayed folding, but depletion of both led to generalized protein misfolding and degradation