Androgens have similar structures with different biological activities. To identify molecular determinants responsible for the activity difference, we have docked six steroidal androgens to the binding site or the sur...Androgens have similar structures with different biological activities. To identify molecular determinants responsible for the activity difference, we have docked six steroidal androgens to the binding site or the surface of androgen receptor by using molecular docking with computational investigation. The energy was calculated respectively based on the QM （quantum mechanics） and MM （molecular mechanics） methods. The result shows that the allosteric modulation of androgen receptor plays an important role in the binding process between androgens and receptor. The open state receptor is less stable than the close state one, but the latter is more favorable for binding with androgens. It is worthy of note that when the androgen receptors binding or without binding with androgen are in close state, they are difficult to return to their open state. This phenomenon is an exception of the well known two-state model theory in which the two states are reversible. Whether the internal of close state androgen receptor has a combination of androgen or not, the androgen receptor surface can be combined with another androgen, and their surface binding energies could be very close. The result is consistent with the experimental observations, but this phenomenon of continuous combination from open state is also an exception of the two-state model theory.展开更多
Thorium as a suitable fertile with higher natural resources in comparison with uranium resources has been remarkably considered by different nuclear energy user countries in the last decades. Its prominent features su...Thorium as a suitable fertile with higher natural resources in comparison with uranium resources has been remarkably considered by different nuclear energy user countries in the last decades. Its prominent features such as suitable possibility for power flattening of a nuclear reactor, applicable breeder blanket to produce^(233)U fissile as well as neutron leakage prevention from a nuclear core has caused its application as power flatter, breeder material or other aimed utilizations be evaluated by the researches. In the present study, neutronics of a modeled CANDU 6loaded with Th O_2 and UO_2fuel rods have been computationally studied. The study aimed at reprocessing of burned Th O_2 seeds at CANDU 6 reactor to recover the total produced uranium, which is to be going under another compound fuel cycle. The obtained results showed all the core reactivity coefficients are sufficiently negative. The modeled core 949 GWd burn-up concluding in 99.99 %depletion of^(235)U initial loads. 18.38 kg of^(233) U was produced in the burnt Th O_2 fuel after 1-year burn-up time. In addition, 31.84 kg of^(239) Pu was produced in the UO_2 spent fuel rods after the burn-up time. After a proposed cooling time, about 50.01 kg of^(233)U will be available in the spent Th O_2 fuel.展开更多
基金supported by the National Natural Science Foundation of China (No. 21073034)the State Key Laboratory of Structural Chemistry (No. 20090060)+1 种基金the Natural Science Foundation of Fujian Province (X0650070)the Science and Technology Development Foundation of Fuzhou University (2010-XY-9)
文摘Androgens have similar structures with different biological activities. To identify molecular determinants responsible for the activity difference, we have docked six steroidal androgens to the binding site or the surface of androgen receptor by using molecular docking with computational investigation. The energy was calculated respectively based on the QM （quantum mechanics） and MM （molecular mechanics） methods. The result shows that the allosteric modulation of androgen receptor plays an important role in the binding process between androgens and receptor. The open state receptor is less stable than the close state one, but the latter is more favorable for binding with androgens. It is worthy of note that when the androgen receptors binding or without binding with androgen are in close state, they are difficult to return to their open state. This phenomenon is an exception of the well known two-state model theory in which the two states are reversible. Whether the internal of close state androgen receptor has a combination of androgen or not, the androgen receptor surface can be combined with another androgen, and their surface binding energies could be very close. The result is consistent with the experimental observations, but this phenomenon of continuous combination from open state is also an exception of the two-state model theory.
文摘Thorium as a suitable fertile with higher natural resources in comparison with uranium resources has been remarkably considered by different nuclear energy user countries in the last decades. Its prominent features such as suitable possibility for power flattening of a nuclear reactor, applicable breeder blanket to produce^(233)U fissile as well as neutron leakage prevention from a nuclear core has caused its application as power flatter, breeder material or other aimed utilizations be evaluated by the researches. In the present study, neutronics of a modeled CANDU 6loaded with Th O_2 and UO_2fuel rods have been computationally studied. The study aimed at reprocessing of burned Th O_2 seeds at CANDU 6 reactor to recover the total produced uranium, which is to be going under another compound fuel cycle. The obtained results showed all the core reactivity coefficients are sufficiently negative. The modeled core 949 GWd burn-up concluding in 99.99 %depletion of^(235)U initial loads. 18.38 kg of^(233) U was produced in the burnt Th O_2 fuel after 1-year burn-up time. In addition, 31.84 kg of^(239) Pu was produced in the UO_2 spent fuel rods after the burn-up time. After a proposed cooling time, about 50.01 kg of^(233)U will be available in the spent Th O_2 fuel.
