1,698 research outputs found
Sensitizing Ability and Toxicity of Iodoacetamide in Radiotherapy of a C3H Mouse Mammary Carcinoma
The radiosensitizing effect of iodoacetamide was studied in a C3H mouse mammary carcinoma together with its toxicity to the host. TCD50 or radiation dose to yield 50% tumour control frequency was determined in tumours treated or untreated with the agent. Results indicated that 15 mg/kg of iodoacetamide sensitized hypoxic tumour cells, as did atmospheric oxygen, and the sensitization was not detectable below this dose. Experiments with fractionated treatments suggested that the reoxygenation occurring during the treatment intervals of 24 hours might be more important in the sterilization of tumour cells than the agent
An Energy-Aware Protocol for Periodical Data Collection in Wireless Sensor Networks
In this paper we propose a protocol for periodical data collection applications in wireless sensor networks. The protocol is energy-aware in the sense that the way of energy consumption used here is evenly distributed. The protocol is chain-oriented and uses data fusion at every sensor node. Compare to other data collection protocols, this protocol shows better performance with respect to both latency and energy. It has been found that the proposed protocol outperforms PEGASIS with respect to latency in data delivery and performs better than that of LEACH with respect to energy. Furthermore, our protocol performs higher number rounds than that of PEGASIS in the case when the first node dies in the network. In a word the protocol shows an outstanding time-energy compromise
Analysis of ELM stability with extended MHD models in JET, JT-60U and future JT-60SA tokamak plasmas
The stability with respect to a peeling–ballooning mode (PBM) was investigated numerically with
extended MHD simulation codes in JET, JT-60U and future JT-60SA plasmas. The MINERVA-DI
code was used to analyze the linear stability, including the effects of rotation and ion diamagnetic drift
( *w i), in JET-ILW and JT-60SA plasmas, and the JOREK code was used to simulate nonlinear
dynamics with rotation, viscosity and resistivity in JT-60U plasmas. It was validated quantitatively
that the ELM trigger condition in JET-ILW plasmas can be reasonably explained by taking into
account both the rotation and *w i effects in the numerical analysis. When deuterium poloidal rotation
is evaluated based on neoclassical theory, an increase in the effective charge of plasma destabilizes
the PBM because of an acceleration of rotation and a decrease in *w i. The difference in the amount of
ELM energy loss in JT-60U plasmas rotating in opposite directions was reproduced qualitatively with
JOREK. By comparing the ELM affected areas with linear eigenfunctions, it was confirmed that the
difference in the linear stability property, due not to the rotation direction but to the plasma density
profile, is thought to be responsible for changing the ELM energy loss just after the ELM crash. A
predictive study to determine the pedestal profiles in JT-60SA was performed by updating the EPED1 model to include the rotation and *w i effects in the PBM stability analysis. It was shown that the plasma rotation predicted with the neoclassical toroidal viscosity degrades the pedestal performance by about 10% by destabilizing the PBM, but the pressure pedestal height will be high enough to achieve the target parameters required for the ITER-like shape inductive scenario in JT-60SA.JSPS KAKENHI 15K06656EURATOM 63305
Non-generality of the Kadowaki-Woods ratio in correlated oxides
An explicit expression for the Kadowaki-Woods ratio in correlated metals is
derived by invoking saturation of the (high-frequency) Fermi-liquid scattering
rate at the Mott-Ioffe-Regel limit. Significant deviations observed in a number
of oxides are quantitatively explained due to variations in carrier density,
dimensionality, unit cell volume and the number of individual sheets in the
Brillouin zone. A generic re-scaling of the original Kadowaki-Woods plot is
also presented.Comment: 9 pages of text, 1 table, 2 figure
Effect of toroidal field ripple on plasma rotation in JET
Dedicated experiments on TF ripple effects on the performance of tokamak plasmas have been carried out at JET. The TF ripple was found to have a profound effect on the plasma rotation. The central Mach number, M, defined as the ratio of the rotation velocity and the thermal velocity, was found to drop as a function of TF ripple amplitude (3) from an average value of M = 0.40-0.55 for operations at the standard JET ripple of 6 = 0.08% to M = 0.25-0.40 for 6 = 0.5% and M = 0.1-0.3 for delta = 1%. TF ripple effects should be considered when estimating the plasma rotation in ITER. With standard co-current injection of neutral beam injection (NBI), plasmas were found to rotate in the co-current direction. However, for higher TF ripple amplitudes (delta similar to 1%) an area of counter rotation developed at the edge of the plasma, while the core kept its co-rotation. The edge counter rotation was found to depend, besides on the TF ripple amplitude, on the edge temperature. The observed reduction of toroidal plasma rotation with increasing TF ripple could partly be explained by TF ripple induced losses of energetic ions, injected by NBI. However, the calculated torque due to these losses was insufficient to explain the observed counter rotation and its scaling with edge parameters. It is suggested that additional TF ripple induced losses of thermal ions contribute to this effect
Unification Picture in Minimal Supersymmetric SU(5) Model with String Remnants
The significant heavy threshold effect is found in the supersymmetric SU(5)
model with two adjoint scalars, one of which is interpreted as a massive string
mode decoupled from the lower-energy particle spectra. This threshold related
with the generic mass splitting of the basic adjoint moduli is shown to alter
properly the running of gauge couplings, thus giving a natural solution to the
string-scale grand unification as prescribed at low energies by LEP precision
measurements and minimal particle content. The further symmetry condition of
the (top-bottom) Yukawa and gauge coupling superunification at a string scale
results in the perfectly working predictions for the top and bottom quark
masses in the absence of any large supersymmetric threshold corrections.Comment: published versio
Structural Ordering and Symmetry Breaking in Cd_2Re_2O_7
Single crystal X-ray diffraction measurements have been carried out on
Cd_2Re_2O_7 near and below the phase transition it exhibits at Tc' ~195 K.
Cd_2Re_2O_7 was recently discovered as the first, and to date only,
superconductor with the cubic pyrochlore structure. Superlattice Bragg peaks
show an apparently continuous structural transition at Tc', however the order
parameter displays anomalously slow growth to ~Tc'/10, and resolution limited
critical-like scattering is seen above Tc'. High resolution measurements show
the high temperature cubic Bragg peaks to split on entering the low temperature
phase, indicating a (likely tetragonal) lowering of symmetry below Tc'.Comment: 4 pages, 4 figure
Altered neuronal physiology, development, and function associated with a common chromosome 15 duplication involving CHRNA7
BACKGROUND: Copy number variants (CNVs) linked to genes involved in nervous system development or function are often associated with neuropsychiatric disease. While CNVs involving deletions generally cause severe and highly penetrant patient phenotypes, CNVs leading to duplications tend instead to exhibit widely variable and less penetrant phenotypic expressivity among affected individuals. CNVs located on chromosome 15q13.3 affecting the alpha-7 nicotinic acetylcholine receptor subunit (CHRNA7) gene contribute to multiple neuropsychiatric disorders with highly variable penetrance. However, the basis of such differential penetrance remains uncharacterized. Here, we generated induced pluripotent stem cell (iPSC) models from first-degree relatives with a 15q13.3 duplication and analyzed their cellular phenotypes to uncover a basis for the dissimilar phenotypic expressivity.
RESULTS: The first-degree relatives studied included a boy with autism and emotional dysregulation (the affected proband-AP) and his clinically unaffected mother (UM), with comparison to unrelated control models lacking this duplication. Potential contributors to neuropsychiatric impairment were modeled in iPSC-derived cortical excitatory and inhibitory neurons. The AP-derived model uniquely exhibited disruptions of cellular physiology and neurodevelopment not observed in either the UM or unrelated controls. These included enhanced neural progenitor proliferation but impaired neuronal differentiation, maturation, and migration, and increased endoplasmic reticulum (ER) stress. Both the neuronal migration deficit and elevated ER stress could be selectively rescued by different pharmacologic agents. Neuronal gene expression was also dysregulated in the AP, including reduced expression of genes related to behavior, psychological disorders, neuritogenesis, neuronal migration, and Wnt, axonal guidance, and GABA receptor signaling. The UM model instead exhibited upregulated expression of genes in many of these same pathways, suggesting that molecular compensation could have contributed to the lack of neurodevelopmental phenotypes in this model. However, both AP- and UM-derived neurons exhibited shared alterations of neuronal function, including increased action potential firing and elevated cholinergic activity, consistent with increased homomeric CHRNA7 channel activity.
CONCLUSIONS: These data define both diagnosis-associated cellular phenotypes and shared functional anomalies related to CHRNA7 duplication that may contribute to variable phenotypic penetrance in individuals with 15q13.3 duplication. The capacity for pharmacological agents to rescue some neurodevelopmental anomalies associated with diagnosis suggests avenues for intervention for carriers of this duplication and other CNVs that cause related disorders
Heavy-Mass Behavior of Ordered Perovskites ACu3Ru4O12 (A = Na, Ca, La)
We synthesized ACu3Ru4O12 (A = Na, Na0.5Ca0.5, Ca, Ca0.5La0.5, La) and
measured their DC magnetization, AC susceptibility, specific heat, and
resistivity, in order to investigate the effects of the hetero-valent
substitution. A broad peak in the DC magnetization around 200 K was observed
only in CaCu3Ru4O12, suggesting the Kondo effect due to localized Cu2+ ions.
However, the electronic specific heat coefficients exhibit large values not
only for CaCu3Ru4O12 but also for all the other samples. Moreover, the Wilson
ratio and the Kadowaki-Woods ratio of our samples are all similar to the values
of other heavy-fermion compounds. These results question the Kondo effect as
the dominant origin of the mass enhancement, and rather indicate the importance
of correlations among itinerant Ru electrons.Comment: 6 pages, 6 figures, to be published in J. Phys. Soc. Jp
Absence of residual quasiparticle conductivity in the underdoped cuprate YBa2Cu4O8
We report here measurements of the in-plane thermal conductivity K(T) of the
underdoped cuprate YBa2Cu4O8 (Y124) below 1K. K(T) is shown to follow a simple,
phononic T^3 dependence at the lowest temperatures for both current directions,
with a negligible linear, quasiparticle contribution. This observation is in
marked contrast with behavior reported in optimally doped cuprates, and implies
that extended zero-energy (or low energy) low-energy quasiparticles are absent
in YBa2Cu4O8 at low temperatures.Comment: RevTex, 4 pages, 2 figures, Revised versio
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