Ultrafast dynamics of the light-matter interaction in a charge-ordered molecular insulator α-(BEDT-TTF)2I3 were studied by pump-probe spectroscopy using few-optical-cycle infrared pulses (pulse width 12 fs). Coherent oscillation of the correlated electrons and subsequent Fano destructive interference with intramolecular vibration were observed in time domain; the results indicated a crucial role for electron-electron interplay in the light-matter interaction leading to the photoinduced insulator-to-metal transition. The qualitative features of this correlated electron motion were reproduced by calculations based on exact many-electron-phonon wave functions.

Avian influenza (AI) virus belongs to the family Orthomyxoviridae and is classified into low-pathogenicity (LP) and highpathogenicity (HP) pathotypes based on a pathogenicity test for chickens. The HPAI virus has over 75% mortality in chickens and can have devastating economic consequences, which can be controlled by a World Organization for Animal Health stamping-out policy, in the poultry industry. The HPAI viruses identified to date are only of the H5 and H7 subtypes and have multiple basic amino acid residues at the hemagglutinin (HA) cleavage site. Of the HPAI viruses, the H5N1 HPAI virus that has continued to circulate in poultry in East Asia since 1996 has been shown to be extremely virulent in chickens (47) and a serious threat to human health. The H5N1 virus has caused over 400 human infections in 15 countries and has a mortality rate of more than 50%.Molecular mechanisms for adaptation of AI viruses from natural reservoirs to new hosts are important for understanding the evolution of influenza viruses. The binding property of hemagglutinin (HA) proteins to avian or mammalian sialic acid receptors (␣2-3 or ␣2-6, respectively) is a first step in overcoming the interspecies barrier. The NS1 protein plays an important role in countering host cell antiviral cytokines or the initial host immune responses of chickens (22, 43). Recently, it was shown that amino acids at position 627 (8, 11) and 701 (21, 46) in polymerase subunit PB2 and 97, 349, and 550 in polymerase subunit PA (40, 45) may play important roles in the adaptation of H5N1 HPAI viruses from birds to mammals. In contrast, the molecular basis of the pathogenicity of AI viruses in chickens on the particle surface HA and neuraminidase (NA) proteins has been intensely investigated. The acquisition of polybasic amino acids at the HA cleavage site is a main determinant permitting the systemic replication of AI viruses in chickens, and the glycosylation patterns of HA molecules influence the accessibility of proteinases to the HA cleavage site (15,35,42). Amino acids in proximity to the HA receptor binding site affect the pathogenicity of the virus in chickens (17). The NA protein is implicated in the release of influenza virus from cells by removing sialic acid residues from the cellderived glycoproteins (33, 47); virus particles with low NA activity cannot be released efficiently from infected cells (23,27). A functional association between the HA and NA proteins has been suggested to directly affect pathogenicity (17,28). Interestingly, recent studies have shown that polymerase subunits (PB1, PB2, and PA) and nucleoprotein (NP) also contribute to pathogenicity in avian species, as has been shown for

We propose the control of group delay and chromatic dispersion in a hollow waveguide with a variable air core and highly reflective mirrors. Both group delay and chromatic dispersion in a hollow optical waveguide increase markedly with decreasing air core. A wide tunability of group velocity and chromatic dispersion is predicted by reducing the air core to nearly half of wavelength. We discuss the potential applications of the proposed hollow waveguide for compact photonic integrated circuits including tunable optical delay lines, interferometers, chromatic dispersion compensators and dispersion slope compensators.

The recent advances in nanotechnology have a great potential to improve the prevention, diagnosis, and treatment of human diseases. Nanomaterials for medical applications are expected to grasp pharmacokinetics and the toxicity for application to medical treatment on the aspect of safety of the nanomaterials and nanodevices. We describe a generation of CdSe nanoparticles [quantum dots (QDs)] conjugated with monoclonal anti-HER2 antibody (Trastuzumab), for single molecular in vivo imaging of breast cancer cells. We established a high-resolution in vivo 3D microscopic system for a novel imaging method at the molecular level. The cancer cells expressing HER2 protein were visualized by the nanoparticles in vivo at subcellular resolution, suggesting future utilization of the system in medical applications to improve drug-delivery systems to target the primary and metastatic tumors for made-to-order treatment. We also describe sentinel node navigation using fluorescent nanoparticles for breast cancer surgery in experimental model, which have shown the potential to be an alternative to existing tracers in the detection of the sentinel node if we select the appropriate particle size and wavelength. Future innovation in cancer imaging by nanotechnology and novel measurement technology will provide great improvement, not only in the clinical field but also in basic medical science for the development of medicine.

Let's twist again: A cation–π interaction between Trp and Arg is designed at the interface between two α helices of a coiled‐coil structure and stabilizes the structure more than Glu and Lys ion‐pair interactions. Two or three Trp–Arg sets form an extended array of interactions (see picture) and increase the melting temperature of the peptide.

No abstract

Hepatocellular carcinoma (HCC) is a malignant tumor associated with a generally poor prognosis and a high rate of recurrence. HCC usually develops in the context of chronic liver diseases, and long-lasting premalignant conditions precede cancer development. A promising therapeutic approach is to eliminate precancerous cells, which are considered as the precursors of cancer stem cells, to prevent further malignant transformation. In this study, we identified a subpopulation of precancerous cells in a rat liver carcinogenesis model, which were enriched in CD133+ CD44 + CD45 -HIS49 -cells that formed part of the hepatic oval cells fraction. Prospective isolation of the precancerous cells using flow cytometry identified stem cell properties such as the ability to expand clonally and differentiate into bi-lineage cell types. Furthermore, an acyclic retinoid, which was recently shown to improve overall survival after HCC resection, directly inhibited the extensive expansion of the isolated precancerous cells in vitro and decreased the emergence of the precancerous cells and their progeny in vivo. Long-term follow-up after the acyclic retinoid treatment confirmed reduction in precancerous changes, ultimately resulting in suppression of HCC development. These findings, together with data from recent clinical trials showing marked reduction in intrahepatic recurrence, suggest that acyclic retinoid directly prevents de novo HCC by inhibiting the development of precancerous cells. Given recent advances in diagnostic techniques and the establishment of surveillance programs, the targeting of precancerous cells may have a huge impact on preventative cancer therapies.

We demonstrate a tunable hollow waveguide distributed Bragg reflector consisting of a grating loaded slab hollow waveguide with a variable air-core. The modeling shows that a change in an air-core thickness enables a large shift of several tens of nanometers in Bragg wavelength due to a change of several percents in a propagation constant. We fabricated a slab hollow waveguide Bragg reflector with 620 mum long and, 190 nm deep 1st-order circular grating composed of SiO2, exhibiting strong Bragg reflection at 1558 nm with an air-core thickness of 10 mum for TM mode. The peak reflectivity is 65% including fiber coupling losses, the 3-dB bandwidth is 2.8 nm and the grating-induced loss is less than 0.5 dB. We demonstrate a 3 nm wavelength tuning of the fabricated hollow waveguide Bragg reflector by changing an air-core thickness from 10 mum to 7.9 mum.