A General SU(2) Formulation for Quantum Searching with Certainty

A general quantum search algorithm with arbitrary unitary transformations and an arbitrary initial state is considered in this work. To serach a marked state with certainty, we have derived, using an SU(2) representation: (1) the matching condition relating the phase rotations in the algorithm, (2) a concise formula for evaluating the required number of iterations for the search, and (3) the final state after the search, with a phase angle in its amplitude of unity modulus. Moreover, the optimal choices and modifications of the phase angles in the Grover kernel is also studied.Comment: 8 pages, 2 figure

Numerical simulation of the blasting vibration response of shallow buried tunnel in complex urban environment

Base on the phase I project of Nanjing metro line IV, the blasting vibration response of shallow buried tunnel in complex urban environment was studied with ANSYS/LS-DYNA, the real load change was simulated with the loading way of measured stress curve, and there was a consistent between numerical simulation results and the measured data. The numerical results indicated that the velocity distribution in different directions were close in the close area (0-2 m); the vertical seismic wave attenuated at the fastest speed in the transferring process, and the radial seismic wave attenuated the fastest in the excavation direction ; in the distance from 2 m to 5 m, the tangential and radial vibration of the initiating side were both obviously larger than the other side of the core tube, which was still more violent than the vertical vibration, and the difference decreases with the distance increases. In the surrounding rocks , the radial vibration velocity was the biggest and attenuated at the fastest speed, which was close to linear attenuation ;the tangential vibration velocity is the smallest with the a relatively gentler damping, the vertical vibration attenuated until 8 m and then increased gradually and the resultant velocity obeyed the exponential damping law

Synergistic binding of actinomycin D and echinomycin to DNA mismatch sites and their combined anti-tumour effects

Combination cancer chemotherapy is one of the most useful treatment methods to achieve a synergistic effect and reduce the toxicity of dosing with a single drug. Here, we use a combination of two well-established anticancer DNA intercalators, actinomycin D (ActD) and echinomycin (Echi), to screen their binding capabilities with DNA duplexes containing different mismatches embedded within Watson-Crick base-pairs. We have found that combining ActD and Echi preferentially stabilised thymine-related T:T mismatches. The enhanced stability of the DNA duplex-drug complexes is mainly due to the cooperative binding of the two drugs to the mismatch duplex, with many stacking interactions between the two different drug molecules. Since the repair of thymine-related mismatches is less efficient in mismatch repair (MMR)-deficient cancer cells, we have also demonstrated that the combination of ActD and Echi exhibits enhanced synergistic effects against MMR-deficient HCT116 cells and synergy is maintained in a MMR-related MLH1 gene knockdown in SW620 cells. We further accessed the clinical potential of the two-drug combination approach with a xenograft mouse model of a colorectal MMR-deficient cancer, which has resulted in a significant synergistic anti-tumour effect. The current study provides a novel approach for the development of combination chemotherapy for the treatment of cancers related to DNA-mismatches