192 research outputs found
Turbulent boundary layer around a group of obstacles in the direction of flow
Results of an investigation of a boundary layer in a turbulent flow on the surface of a wall having a group of obstacles on the path of flow are presented with regard to the mean velocity field, velocity distribution of the two dimensional flow, wall surface shear stresses and Reynolds stresses measured in a downstream cross section where an interference of boundary layers takes place in a flow around adjacent obstacles arranged on the path of flow
Statistical study on propagation characteristics of Omega signals (VLF) in magnetosphere detected by the Akebono satellite
This paper shows a statistical analysis of 10.2 kHz Omega broadcasts of an
artificial signal broadcast from ground stations, propagated in the
plasmasphere, and detected using an automatic detection method we developed. We
study the propagation patterns of the Omega signals to understand the
propagation characteristics that are strongly affected by plasmaspheric
electron density and the ambient magnetic field. We show the unique propagation
patterns of the Omega 10.2 kHz signal when it was broadcast from two
high-middle-latitude stations. We use about eight years of data captured by the
Poynting flux analyzer subsystem on board the Akebono satellite from October
1989 to September 1997. We demonstrate that the signals broadcast from almost
the same latitude (in geomagnetic coordinates) propagated differently depending
on the geographic latitude. We also study propagation characteristics as a
function of local time, season, and solar activity. The Omega signal tended to
propagate farther on the nightside than on the dayside and was more widely
distributed during winter than during summer. When solar activity was at
maximum, the Omega signal propagated at a lower intensity level. In contrast,
when solar activity was at minimum, the Omega signal propagated at a higher
intensity and farther from the transmitter station.Comment: 14 pages, 12 figure
The ground state of Sr3Ru2O7 revisited; Fermi liquid close to a ferromagnetic instability
We show that single-crystalline Sr3Ru2O7 grown by a floating-zone technique
is an isotropic paramagnet and a quasi-two dimensional metal as spin-triplet
superconducting Sr2RuO4 is. The ground state is Fermi liquid with very low
residual resistivity (3 micro ohm cm for in-plane currents) and a nearly
ferromagnetic metal with the largest Wilson ratio Rw>10 among paramagnets so
far. This contrasts with the ferromagnetic order at Tc=104 K reported on single
crystals grown by a flux method [Cao et al., Phys. Rev. B 55, R672 (1997)]. We
have also found a dramatic changeover from paramagnetism to ferromagnetism
under applied pressure. This suggests the existence of a substantial
ferromagnetic instability on the verge of a quantum phase transition in the
Fermi liquid state.Comment: 5 pages, 4 figures, to be published in Phys. Rev. B : Rapid co
Nonlinear Sigma model method for the J1-J2 Heisenberg model: disordered ground state with plaquette symmetry
A novel nonlinear sigma model method is proposed for the two-dimensional
J1-J2 model, which is extended to include plaquette-type distortion. The
nonlinear sigma model is properly derived without spoiling the original spin
degrees of freedom. The method shows that a single disordered phase
continuously extends from a frustrated uniform regime to an unfrustrated
distorted regime. By the continuity and Oshikawa's commensurability condition,
the disordered ground states for the uniform J1-J2 model are plaquette states
with four-fold degeneracy.Comment: 4 pages (including 2 figures
A global review on short peptides: frontiers and perspectives
Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide “drugs” initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed
Self-adjuvanting polymer-peptide conjugates as therapeutic vaccine candidates against cervical cancer
Dendrimers are structurally well-defined, synthetic polymers with sizes and physicochemical properties often resembling those of biomacromolecules (e.g. proteins). As a result they are promising candidates for peptide-based vaccine delivery platforms. Herein, we established a synthetic pathway to conjugate a human papillomavirus (HPV) E7 protein-derived peptide antigen to a star-polymer to create a macromolecular vaccine candidate to treat HPV-related cancers. These conjugates were able to reduce tumor growth and eradicate E7-expressing TC-1 tumors in mice after a single immunization, without the help of any external adjuvant
Dysregulation of Gene Expression in the Artificial Human Trisomy Cells of Chromosome 8 Associated with Transformed Cell Phenotypes
A change in chromosome number, known as aneuploidy, is a common characteristic of cancer. Aneuploidy disrupts gene expression in human cancer cells and immortalized human epithelial cells, but not in normal human cells. However, the relationship between aneuploidy and cancer remains unclear. To study the effects of aneuploidy in normal human cells, we generated artificial cells of human primary fibroblast having three chromosome 8 (trisomy 8 cells) by using microcell-mediated chromosome transfer technique. In addition to decreased proliferation, the trisomy 8 cells lost contact inhibition and reproliferated after exhibiting senescence-like characteristics that are typical of transformed cells. Furthermore, the trisomy 8 cells exhibited chromosome instability, and the overall gene expression profile based on microarray analyses was significantly different from that of diploid human primary fibroblasts. Our data suggest that aneuploidy, even a single chromosome gain, can be introduced into normal human cells and causes, in some cases, a partial cancer phenotype due to a disruption in overall gene expression
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