193 research outputs found
Fantastic Behavior of High-TC Superconductor Junctions: Tunable Superconductivity
Carrier injection performed in oxygen-deficient YBa2Cu3O7(YBCO)
hetero-structure junctions exhibited tunable resistance that was entirely
different with behaviors of semiconductor devices. Tunable superconductivity in
YBCO junctions, increasing over 20 K in transition temperature, has achieved by
using electric processes. To our knowledge, this is the first observation that
intrinsic property of high TC superconductors superconductivity can be adjusted
as tunable functional parameters of devices. The fantastic phenomenon caused by
carrier injection was discussed based on a proposed charge carrier
self-trapping model and BCS theory.Comment: 5 pages, 4 figure
Phase structure in the baryon density-dependent quark mass model
The properties of phase diagram of strange quark matter in equilibrium with
hadronic matter at finite temperature are studied, where the quark phase and
hadron phase are treated by baryon density-dependent quark mass model and
hadron resonance gas model with hard core repulsion factor, respectively. Our
results indicate that the strangeness fraction fs, perturbation parameter C,
and confinement parameter D have strong influence on the properties of phase
diagram and the formation of strangelets, where a large fs, small C and D favor
the formation of strangelets. Consider the isentropic expansion process, we
found that the initial entropy per baryon is about 5, which gives a large
probability for the formation of strangelets. Furthermore, as the strangeness
fraction fs and one gluon-exchange interaction strength C decrease and
confinement parameter D increases, the reheating effect becomes more
significant, reducing the possibility of forming strangelets. The new phase
diagram could support a massive compact star with the maximum mass exceeding
twice the solar mass and have a significant impact on the mass-radius
relationship for hybrid stars
Strangelets at finite temperature: nucleon emission rates, interface and shell effects
We investigate the properties of strangelets at finite temperature , where
an equivparticle model is adopted with both the linear confinement and
leading-order perturbative interactions accounted for using density-dependent
quark masses. The shell effects are examined by solving the Dirac equations for
quarks in the mean-field approximation, which diminish with temperature as the
occupation probability of each single-particle levels fixed by the Fermi-Dirac
statistics, i.e., shell dampening. Consequently, instead of decreasing with
temperature, the surface tension extracted from a liquid-drop formula increases
with until reaching its peak at -40 MeV with vanishing shell
corrections, where the formula roughly reproduces the free energy per baryon of
all strangelets. The curvature term, nevertheless, decreases with despite
the presence of shell effects. The neutron and proton emission rates are fixed
microscopically according to the external nucleon gas densities that are in
equilibrium with strangelets, which generally increase with (
MeV) for stable strangelets but decrease for those that are unstable against
nucleon emission at . The energy, free energy, entropy, charge-to-mass
ratio, strangeness per baryon, and root-mean-square radius of -stable
strangelets obtained with various parameter sets are presented as well. The
results indicated in this work are useful for understanding the products of
binary compact star mergers and heavy-ion collisions
Metasurface-assisted phase-matching-free second harmonic generation in lithium niobate waveguides
The phase-matching condition is a key aspect in nonlinear wavelength conversion processes, which requires the momenta of the photons involved in the processes to be conserved. Conventionally, nonlinear phase matching is achieved using either birefringent or periodically poled nonlinear crystals, which requires careful dispersion engineering and is usually narrowband. In recent years, metasurfaces consisting of densely packed arrays of optical antennas have been demonstrated to provide an effective optical momentum to bend light in arbitrary ways. Here, we demonstrate that gradient metasurface structures consisting of phased array antennas are able to circumvent the phase-matching requirement in on-chip nonlinear wavelength conversion. We experimentally demonstrate phase-matching-free second harmonic generation over many coherent lengths in thin film lithium niobate waveguides patterned with the gradient metasurfaces. Efficient second harmonic generation in the metasurface-based devices is observed over a wide range of pump wavelengths (ΓΒ» = 1580-1650 nm)
(E)-Nβ²-(2,5-DimethoxyΒbenzylΒidene)-2,4-dihydroxyΒbenzohydrazide
In the title compound, C16H16N2O5, the dihedral angle between the two benzene rings is 4.2β
(2)Β° and an intraΒmolecular OβHβ―O hydrogen bond generates an S(6) ring. In the crystal, molΒecules are linked into layers lying parallel to the bc plane by OβHβ―O and NβHβ―O hydrogen bonds
Coseeded Schwann cells myelinate neurites from differentiated neural stem cells in neurotrophin-3-loaded PLGA carriers
Biomaterials and neurotrophic factors represent promising guidance for neural repair. In this study, we combined poly-(lactic acid-co-glycolic acid) (PLGA) conduits and neurotrophin-3 (NT-3) to generate NT-3-loaded PLGA carriers in vitro. Bioactive NT-3 was released stably and constantly from PLGA conduits for up to 4 weeks. Neural stem cells (NSCs) and Schwann cells (SCs) were coseeded into an NT-releasing scaffold system and cultured for 14 days. Immunoreactivity against Map2 showed that most of the grafted cells (>80%) were differentiated toward neurons. Double-immunostaining for synaptogenesis and myelination revealed the formation of synaptic structures and myelin sheaths in the coculture, which was also observed under electron microscope. Furthermore, under depolarizing conditions, these synapses were excitable and capable of releasing synaptic vesicles labeled with FM1-43 or FM4-64. Taken together, coseeding NSCs and SCs into NT-3-loaded PLGA carriers increased the differentiation of NSCs into neurons, developed synaptic connections, exhibited synaptic activities, and myelination of neurites by the accompanying SCs. These results provide an experimental basis that supports transplantation of functional neural construction in spinal cord injury
Immunoproteomic Analysis of Human Serological Antibody Responses to Vaccination with Whole-Cell Pertussis Vaccine (WCV)
BACKGROUND: Pertussis (whooping cough) caused by Bordetella pertussis (B.p), continues to be a serious public health threat. Vaccination is the most economical and effective strategy for preventing and controlling pertussis. However, few systematic investigations of actual human immune responses to pertussis vaccines have been performed. Therefore, we utilized a combination of two-dimensional electrophoresis (2-DE), immunoblotting, and mass spectrometry to reveal the entire antigenic proteome of whole-cell pertussis vaccine (WCV) targeted by the human immune system as a first step toward evaluating the repertoire of human humoral immune responses against WCV. METHODOLOGY/PRINCIPAL FINDINGS: Immunoproteomic profiling of total membrane enriched proteins and extracellular proteins of Chinese WCV strain 58003 identified a total of 30 immunoreactive proteins. Seven are known pertussis antigens including Pertactin, Serum resistance protein, chaperonin GroEL and two OMP porins. Sixteen have been documented to be immunogenic in other pathogens but not in B.p, and the immunogenicity of the last seven proteins was found for the first time. Furthermore, by comparison of the human and murine immunoproteomes of B.p, with the exception of four human immunoreactive proteins that were also reactive with mouse immune sera, a unique group of antigens including more than 20 novel immunoreactive proteins that uniquely reacted with human immune serum was confirmed. CONCLUSIONS/SIGNIFICANCE: This study is the first time that the repertoire of human serum antibody responses against WCV was comprehensively investigated, and a small number of previously unidentified antigens of WCV were also found by means of the classic immunoproteomic strategy. Further research on these newly identified predominant antigens of B.p exclusively against humans will not only remarkably accelerate the development of diagnostic biomarkers and subunit vaccines but also provide detailed insight into human immunity mechanisms against WCV. In particular, this work highlights the heterogeneity of the B.p immunoreactivity patterns of the mouse model and the human host
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