1,286 research outputs found
miR-375 suppresses IGF1R expression and contributes to inhibition cell progression in laryngeal squamous cell carcinoma
published_or_final_versio
Integer and half-integer flux-quantum transitions in a niobium/iron-pnictide loop
The recent discovery of iron-based superconductors challenges the existing
paradigm of high-temperature superconductivity. Owing to their unusual
multi-orbital band structure, magnetism, and electron correlation, theories
propose a unique sign reversed s-wave pairing state, with the order parameter
changing sign between the electron and hole Fermi pockets. However, because of
the complex Fermi surface topology and material related issues, the predicted
sign reversal remains unconfirmed. Here we report a novel phase-sensitive
technique for probing unconventional pairing symmetry in the polycrystalline
iron-pnictides. Through the observation of both integer and half-integer
flux-quantum transitions in composite niobium/iron-pnictide loops, we provide
the first phase-sensitive evidence of the sign change of the order parameter in
NdFeAsO0.88F0.12, lending strong support for microscopic models predicting
unconventional s-wave pairing symmetry. These findings have important
implications on the mechanism of pnictide superconductivity, and lay the
groundwork for future studies of new physics arising from the exotic order in
the FeAs-based superconductors.Comment: 23 pages, including 4 figures and supplementary informatio
Demonstration of a self-pulsing photonic crystal Fano laser
Semiconductor lasers in use today rely on mirrors based on the reflection at
a cleaved facet or Bragg reflection from a periodic stack of layers. Here, we
demonstrate an ultra-small laser with a mirror based on the Fano resonance
between a continuum of waveguide modes and the discrete resonance of a
nanocavity. The Fano resonance leads to unique laser characteristics. Since the
Fano mirror is very narrow-band compared to conventional lasers, the laser is
single-mode and in particular, it can be modulated via the mirror. We show,
experimentally and theoretically, that nonlinearities in the mirror may even
promote the generation of a self-sustained train of pulses at gigahertz
frequencies, an effect that was previously only observed in macroscopic lasers.
Such a source is of interest for a number of applications within integrated
photonics
Clinical, Virological and Immunological Features from Patients Infected with Re-Emergent Avian-Origin Human H7N9 Influenza Disease of Varying Severity in Guangdong Province
The second wave of avian influenza H7N9 virus outbreak in humans spread to the Guangdong province of China by August of 2013 and this virus is now endemic in poultry in this region.Background
The second wave of avian influenza H7N9 virus outbreak in humans spread to the Guangdong province of China by August of 2013 and this virus is now endemic in poultry in this region.
Methods
Five patients with H7N9 virus infection admitted to our hospital during August 2013 to February 2014 were intensively investigated. Viral load in the respiratory tract was determined by quantitative polymerase chain reaction (Q-PCR) and cytokine levels were measured by bead-based flow cytometery.
Results
Four patients survived and one died. Viral load in different clinical specimens was correlated with cytokine levels in plasma and broncho-alveolar fluid (BALF), therapeutic modalities used and clinical outcome. Intravenous zanamivir appeared to be better than peramivir as salvage therapy in patients who failed to respond to oseltamivir. Higher and more prolonged viral load was found in the sputum or endotracheal aspirates compared to throat swabs. Upregulation of proinflammatory cytokines IP-10, MCP-1, MIG, MIP-1α/β, IL-1β and IL-8 was found in the plasma and BALF samples. The levels of cytokines in the plasma and viral load were correlated with disease severity. Reactivation of herpes simplex virus type 1(HSV-1) was found in three out of five patients (60%).
Conclusion
Expectorated sputum or endotracheal aspirate specimens are preferable to throat swabs for detecting and monitoring H7N9 virus. Severity of the disease was correlated to the viral load in the respiratory tract as well as the extents of cytokinemia. Reactivation of HSV-1 may contribute to clinical outcome.published_or_final_versio
Thermoelectric properties of tetrathiotetracene iodide crystals: modeling and experiment
A more complete physical model for nanostructured crystals of tetrathiotetracene-iodide that takes into account the interaction of carriers with the neighboring one-dimensional (1D) conductive chains and also the scattering on impurities and defects is presented. For simplicity, the 2D approximation is applied. It is shown that this model describes very well the temperature dependencies of electrical conductivity in the temperature interval between 180 and 300 K, and of the Seebeck coefficient between 50 and 300 K, the highest temperature for which the measurements were reported. For lower temperatures, it is necessary to also consider the fluctuations of dielectric phase that appear before the metal–dielectric transition. It is found that the predictions made in the 1D approximation are valid only if the crystal purity is not very high, and the electrical conductivity is limited up to ∼3.5×106Ω−1m−1 and the thermoelectric figure of merit up to ZT∼4
A general strategy for synthesis of metal oxide nanoparticles attached on carbon nanomaterials
We report a general strategy for synthesis of a large variety of metal oxide nanoparticles on different carbon nanomaterials (CNMs), including single-walled carbon nanotubes, multi-walled carbon nanotubes, and a few-layer graphene. The approach was based on the π-π interaction between CNMs and modified aromatic organic ligands, which acted as bridges connecting metal ions and CNMs. Our methods can be applicable for a large variety of metal ions, thus offering a great potential application
Seeking legitimacy through CSR: Institutional Pressures and Corporate Responses of Multinationals in Sri Lanka
Arguably, the corporate social responsibility (CSR) practices of multinational enterprises (MNEs) are influenced by a wide range of both internal and external factors. Perhaps most critical among the exogenous forces operating on MNEs are those exerted by state and other key institutional actors in host countries. Crucially, academic research conducted to date offers little data about how MNEs use their CSR activities to strategically manage their relationship with those actors in order to gain legitimisation advantages in host countries. This paper addresses that gap by exploring interactions between external institutional pressures and firm-level CSR activities, which take the form of community initiatives, to examine how MNEs develop their legitimacy-seeking policies and practices. In focusing on a developing country, Sri Lanka, this paper provides valuable insights into how MNEs instrumentally utilise community initiatives in a country where relationship-building with governmental and other powerful non-governmental actors can be vitally important for the long-term viability of the business. Drawing on neo-institutional theory and CSR literature, this paper examines and contributes to the embryonic but emerging debate about the instrumental and political implications of CSR. The evidence presented and discussed here reveals the extent to which, and the reasons why, MNEs engage in complex legitimacy-seeking relationships with Sri Lankan institutions
- …