3,368 research outputs found
Analysis of Unemployment During Transition to a Market Economy:
Using self-gathered data and the hazard model, we analyzed the reasons laid-off workers in the Beijing area remained unemployed. For the laid-off workers who were eventually reemployed, we used the Tobit model to explain the change in wages between their pre- and post-layoff employment. The results of these analyses revealed that, although Chinaās policy of laying off workers from state-owned enterprises without completely severing the relationship accelerated the establishment of a labor market to some extent, with prolonged time the laid-off workers are out of work, the policy was an obstacle to the labor-marketing effort. Moreover, it was an obstacle to implementing and improving an unemployment benefits system. They also showed that laid-off workers with worked experience under the traditional system need to be reeducated to enable them to adapt to the new economic environment as well as to be taught new skills, especially those workers who were managers. Additionally, the "lay-off" is not only a policy in special phase during the process of Chinese economic system reform, but also a special phenomenon, which is the structural unemployment revealed from Chinese economic system. This unemployment due to changes in industry structure means that the government must adopt a more active employment policy
Production of proton-rich nuclei around Z=84-90 in fusion-evaporation reactions
Within the framework of the dinuclear system model, production cross sections
of proton-rich nuclei with charged numbers of Z=84-90 are investigated
systematically. Possible combinations with the Si, S, Ar
bombarding the target nuclides Ho, Tm, Yb,
Lu, Hf and Ta are analyzed thoroughly. The
optimal excitation energies and evaporation channels are proposed to produce
the proton-rich nuclei. The systems are feasible to be constructed in
experiments. It is found that the neutron shell closure of N=126 is of
importance during the evaporation of neutrons. The experimental excitation
functions in the Ar induced reactions can be nicely reproduced. The
charged particle evaporation is comparable with neutrons in cooling the excited
proton-rich nuclei, in particular for the channels with and proton
evaporation. The production cross section increases with the mass asymmetry of
colliding systems because of the decrease of the inner fusion barrier. The
channels with pure neutron evaporation depend on the isotopic targets. But it
is different for the channels with charged particles and more sensitive to the
odd-even effect.Comment: 15 pages, 10 figures. arXiv admin note: text overlap with
arXiv:0803.1117, arXiv:0707.258
Ī±ā² Type TiāNbāZr alloys with ultra-low Young's modulus and high strength
AbstractĪ±ā² phase based TiāNbāZr alloys with low Young's modulus and high strength were prepared, and their microstructure and mechanical properties were characterized. It was revealed that the lattice expansion by Nb and Zr addition as well as the presence of a few of Ī±ā³ martensite might be responsible for the low modulus achieved. Tiā15Nbā9Zr alloy, with ultralow modulus of 39GPa and high strength of 850MPa, could be a potential candidate for biomedical applications
Expression and clinical significance of multidrug resistance proteins in brain tumors
<p>Abstract</p> <p>Background</p> <p>To investigate the mechanisms of multidrug resistance of brain tumors, to identify the site of cellular expression of P-gp in human brains in situ and to morphologically determine whether an association may exist between P-gp and caveolin-1.</p> <p>Methods</p> <p>Immunohistochemistry was used to detect the expression and location of P-glycoprotein (P-gp), Multidrug resistance-associated protein (MDR), Lung resistance-related protein (LRP), Topoisomerase II (Topo II) and Glutathione-S-Ļ (GST-Ļ) in 30 patient tumor tissues and 5 normal brain tissues. The sections were subjected to double labeling for P-gp (TRITC labeled) and caveolin-1 (FITC labeled). The location and characteristics of expression of the two proteins in the blood brain barrier(BBB) was observed using a laser scanning microscope.</p> <p>Results</p> <p>High expression of P-gp was detected in vessel walls and the tissue surrounding the vessels. However, expression of P-gp was low in tumor cells. The expression of the other 4 multidrug resistance proteins was not observed in the vessel walls. Laser scanning microscopy showed P-gp and caveolin-1 co-expression: the two proteins co-localized either in the luminal endothelial compartment or at the border of the luminal/abluminal compartments.</p> <p>Conclusion</p> <p>Chemotherapeutics drugs are interrupted in the end-feet of neuroepithelial cells of the BBB by P-gp, which weakens the chemotherapeutic effect. P-gp marks the BBB, and the transporter is localized in the luminal endothelial compartment where it co-localizes with caveolin-1.</p
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