10,568 research outputs found
Evaluation of the radiosensitizing potency of chemotherapeutic agents in prostate cancer cells
PURPOSE:
Despite recent advances in the treatment of metastatic prostate cancer, survival rates are low and treatment options are limited to chemotherapy and hormonal therapy. Although ionizing radiation is used to treat localized and metastatic prostate cancer, the most efficient use of radiotherapy is yet to be defined. Our purpose was to determine in vitro the potential benefit to be gained by combining radiation treatment with cytotoxic drugs.
MATERIALS AND METHODS:
Inhibitors of DNA repair and heat shock protein 90 and an inducer of oxidative stress were evaluated in combination with x-radiation for their capacity to reduce clonogenic survival and delay the growth of multicellular tumor spheroids.
RESULTS:
Inhibitors of the PARP DNA repair pathway, olaparib and rucaparib, and the HSP90 inhibitor 17-DMAG, enhanced the clonogenic cell kill and spheroid growth delay induced by x-radiation. However, the oxidative stress-inducing drug elesclomol failed to potentiate the effects of x-radiation. PARP inhibitors arrested cells in the G2/M phase when administered as single agents or in combination with radiation, whereas elesclomol and 17-DMAG did not affect radiation-induced cell cycle modulation.
CONCLUSIONS:
These results indicate that radiotherapy of prostate cancer may be optimized by combination with inhibitors of PARP or HSP90, but not elesclomol
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Assessment of Scale-Loss to Atlantic Salmon (Salmo Salar L.) Smolts from Passage Through an Archimedean Screw Turbine
The potential for external damage to Atlantic salmon (Salmo salar L.) smolts from passage through an Archimedean screw turbine was tested with controlled field trials at two turbine speeds. Change in external condition of smolts was measured by grading photographs of individual fish for scale-loss before and after the tests. Results were compared between turbine-passed and control smolts. There were no significant differences in proportions of fish with new scale-loss between treatment and control smolts. New scale-loss of between 4 and 30% was seen in 7.46% of turbine-passed smolts, exceeding the prevalence in control smolts by 2.46%. Of these, 1.49% had minor scale-loss of 5-9%. Minor scale-loss was more prevalent for both groups at the faster turbine speed, although differences between treatment and control groups were more apparent at the slower speed
Job growth and finance : are some financial institutions better suited to early stages of development than others?
This paper combines firm-level data from 89 countries with updated country-level data on financial structure, and uses two estimation approaches. It finds that in low-income countries, labor growth is swifter in countries with a higher level of private credit/gross domestic product; the positive effect of bank credit is especially pronounced in industries that depend heavily on external finance; and banking development is positively associated with more physical and human capital investment. These findings are consistent with predictions from new structural economics. In high-income countries, labor growth rates are increasing in the level of stock market capitalization, which is also consistent with predictions from new structural economics, although the analysis is unable to provide evidence that the association is causal. It finds no evidence that small-scale firms in low-income countries benefit most from private credit market development. Rather, the labor growth rates of larger, capital-intensive firms increase more with the level of private credit market development, a finding consistent with the history-based political economy view that banking systems in low-income countries serve the interests of the elite, rather than providing broad-based access to financial services.Debt Markets,Banks&Banking Reform,Access to Finance,Economic Theory&Research,Emerging Markets
Manufacturing Wage Dispersion: An End Game Interpretation
macroeconomics, manufacturing, wage dispersion, cyclical swings
Generalized Quantum Search with Parallelism
We generalize Grover's unstructured quantum search algorithm to enable it to
use an arbitrary starting superposition and an arbitrary unitary matrix
simultaneously. We derive an exact formula for the probability of the
generalized Grover's algorithm succeeding after n iterations. We show that the
fully generalized formula reduces to the special cases considered by previous
authors. We then use the generalized formula to determine the optimal strategy
for using the unstructured quantum search algorithm. On average the optimal
strategy is about 12% better than the naive use of Grover's algorithm. The
speedup obtained is not dramatic but it illustrates that a hybrid use of
quantum computing and classical computing techniques can yield a performance
that is better than either alone. We extend the analysis to the case of a
society of k quantum searches acting in parallel. We derive an analytic formula
that connects the degree of parallelism with the optimal strategy for
k-parallel quantum search. We then derive the formula for the expected speed of
k-parallel quantum search.Comment: 14 pages, 2 figure
Design and trade-offs of a pole-sitter mission
This paper provides a mission analysis and systems design of a pole-sitter mission, i.e. a spacecraft that is continuously above an Earth Pole, and can provide real-time, continuous and hemispherical coverage of the polar regions. Two different propulsion strategies are proposed: solar electric propulsion (SEP) and SEP hybridized with a solar sail. For both, minimum-propellant pole-sitter orbits and transfers are designed, assuming Soyuz and Ariane 5 launch options. A mass budget analysis allows for a tradeoff between mission lifetime and payload mass capacity (up to 7 years for 100 kg), and candidate payloads for a range of applications are investigated
The suppression of DNA repair induced by PARP-1 inhibitors rucaparib and olaparib in combination with the radiopharmaceutical 131I-MIBG in noradrenaline transporter-expressing xenograft tumors
No abstract available
Reduction of trapped ion anomalous heating by in situ surface plasma cleaning
Anomalous motional heating is a major obstacle to scalable quantum
information processing with trapped ions. While the source of this heating is
not yet understood, several previous studies suggest that surface contaminants
may be largely responsible. We demonstrate an improvement by a factor of four
in the room-temperature heating rate of a niobium surface electrode trap by in
situ plasma cleaning of the trap surface. This surface treatment was performed
with a simple homebuilt coil assembly and commercially-available matching
network and is considerably gentler than other treatments, such as ion milling
or laser cleaning, that have previously been shown to improve ion heating
rates. We do not see an improvement in the heating rate when the trap is
operated at cryogenic temperatures, pointing to a role of thermally-activated
surface contaminants in motional heating whose activity may freeze out at low
temperatures.Comment: 5 pages, 4 figure
The disk-halo interface in edge-on spirals
We are studying the disk-halo interface in several edge-on spiral galaxies through extensive imagery in H(alpha) and other emission lines from Diffuse Ionized Gas (DIG), also referred to as the Warm Ionized Medium (WIM). In addition, for the nearby Sc galaxy NGC4631 we have obtained x-ray observations with ROSAT, to map the distribution of hot (10(exp 6) - 10(exp 7)) gas in the disk and halo. Here we present initial results for two late-type spirals, NGC4244 and NGC4631
Evidence to Suggest That Teeth Act as Human Ornament Displays Signalling Mate Quality
Ornament displays seen in animals convey information about genetic quality, developmental history and current disease state to both prospective sexual partners and potential rivals. In this context, showing of teeth through smiles etc is a characteristic feature of human social interaction. Tooth development is influenced by genetic and environmental factors. Adult teeth record environmental and traumatic events, as well as the effects of disease and ageing. Teeth are therefore a rich source of information about individuals and their histories. This study examined the effects of digital manipulations of tooth colour and spacing. Results showed that deviation away from normal spacing and/or the presence of yellowed colouration had negative effects on ratings of attractiveness and that these effects were markedly stronger in female models. Whitening had no effect beyond that produced by natural colouration. This indicates that these colour induced alterations in ratings of attractiveness are mediated by increased/decreased yellowing rather than whitening per se. Teeth become yellower and darker with age. Therefore it is suggested that whilst the teeth of both sexes act as human ornament displays, the female display is more complex because it additionally signals residual reproductive value
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