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121 results on '"Montazeri, S. A."'

1. Phase transitions in random circuit sampling

Author

Morvan, A., Villalonga, B., Mi, X., Mandrà, S., Bengtsson, A., Klimov, P. V., Chen, Z., Hong, S., Erickson, C., Drozdov, I. K., Chau, J., Laun, G., Movassagh, R., Asfaw, A., Brandão, L. T. A. N., Peralta, R., Abanin, D., Acharya, R., Allen, R., Andersen, T. I., Anderson, K., Ansmann, M., Arute, F., Arya, K., Atalaya, J., Bardin, J. C., Bilmes, A., Bortoli, G., Bourassa, A., Bovaird, J., Brill, L., Broughton, M., Buckley, B. B., Buell, D. A., Burger, T., Burkett, B., Bushnell, N., Campero, J., Chang, H.-S., Chiaro, B., Chik, D., Chou, C., Cogan, J., Collins, R., Conner, P., Courtney, W., Crook, A. L., Curtin, B., Debroy, D. M., Barba, A. Del Toro, Demura, S., Paolo, A. Di, Dunsworth, A., Faoro, L., Farhi, E., Fatemi, R., Ferreira, V. S., Burgos, L. Flores, Forati, E., Fowler, A. G., Foxen, B., Garcia, G., Genois, É., Giang, W., Gidney, C., Gilboa, D., Giustina, M., Gosula, R., Dau, A. Grajales, Gross, J. A., Habegger, S., Hamilton, M. C., Hansen, M., Harrigan, M. P., Harrington, S. D., Heu, P., Hoffmann, M. R., Huang, T., Huff, A., Huggins, W. J., Ioffe, L. B., Isakov, S. V., Iveland, J., Jeffrey, E., Jiang, Z., Jones, C., Juhas, P., Kafri, D., Khattar, T., Khezri, M., Kieferová, M., Kim, S., Kitaev, A., Klots, A. R., Korotkov, A. N., Kostritsa, F., Kreikebaum, J. M., Landhuis, D., Laptev, P., Lau, K.-M., Laws, L., Lee, J., Lee, K. W., Lensky, Y. D., Lester, B. J., Lill, A. T., Liu, W., Livingston, W. P., Locharla, A., Malone, F. D., Martin, O., Martin, S., McClean, J. R., McEwen, M., Miao, K. C., Mieszala, A., Montazeri, S., Mruczkiewicz, W., Naaman, O., Neeley, M., Neill, C., Nersisyan, A., Newman, M., Ng, J. H., Nguyen, A., Nguyen, M., Niu, M. Yuezhen, O’Brien, T. E., Omonije, S., Opremcak, A., Petukhov, A., Potter, R., Pryadko, L. P., Quintana, C., Rhodes, D. M., Rocque, C., Rosenberg, E., Rubin, N. C., Saei, N., Sank, D., Sankaragomathi, K., Satzinger, K. J., Schurkus, H. F., Schuster, C., Shearn, M. J., Shorter, A., Shutty, N., Shvarts, V., Sivak, V., Skruzny, J., Smith, W. C., Somma, R. D., Sterling, G., Strain, D., Szalay, M., Thor, D., Torres, A., Vidal, G., Heidweiller, C. Vollgraff, White, T., Woo, B. W. K., Xing, C., Yao, Z. J., Yeh, P., Yoo, J., Young, G., Zalcman, A., Zhang, Y., Zhu, N., Zobrist, N., Rieffel, E. G., Biswas, R., Babbush, R., Bacon, D., Hilton, J., Lucero, E., Neven, H., Megrant, A., Kelly, J., Roushan, P., Aleiner, I., Smelyanskiy, V., Kechedzhi, K., Chen, Y., and Boixo, S.

Published
2024
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2. Stable Quantum-Correlated Many Body States through Engineered Dissipation

Author

Mi, X., Michailidis, A. A., Shabani, S., Miao, K. C., Klimov, P. V., Lloyd, J., Rosenberg, E., Acharya, R., Aleiner, I., Andersen, T. I., Ansmann, M., Arute, F., Arya, K., Asfaw, A., Atalaya, J., Bardin, J. C., Bengtsson, A., Bortoli, G., Bourassa, A., Bovaird, J., Brill, L., Broughton, M., Buckley, B. B., Buell, D. A., Burger, T., Burkett, B., Bushnell, N., Chen, Z., Chiaro, B., Chik, D., Chou, C., Cogan, J., Collins, R., Conner, P., Courtney, W., Crook, A. L., Curtin, B., Dau, A. G., Debroy, D. M., Barba, A. Del Toro, Demura, S., Di Paolo, A., Drozdov, I. K., Dunsworth, A., Erickson, C., Faoro, L., Farhi, E., Fatemi, R., Ferreira, V. S., Forati, L. F. Burgos E., Fowler, A. G., Foxen, B., Genois, E., Giang, W., Gidney, C., Gilboa, D., Giustina, M., Gosula, R., Gross, J. A., Habegger, S., Hamilton, M. C., Hansen, M., Harrigan, M. P., Harrington, S. D., Heu, P., Hoffmann, M. R., Hong, S., Huang, T., Huff, A., Huggins, W. J., Ioffe, L. B., Isakov, S. V., Iveland, J., Jeffrey, E., Jiang, Z., Jones, C., Juhas, P., Kafri, D., Kechedzhi, K., Khattar, T., Khezri, M., Kieferova, M., Kim, S., Kitaev, A., Klots, A. R., Korotkov, A. N., Kostritsa, F., Kreikebaum, J. M., Landhuis, D., Laptev, P., Lau, K. -M., Laws, L., Lee, J., Lee, K. W., Lensky, Y. D., Lester, B. J., Lill, A. T., Liu, W., Locharla, A., Malone, F. D., Martin, O., McClean, J. R., McEwen, M., Mieszala, A., Montazeri, S., Morvan, A., Movassagh, R., Mruczkiewicz, W., Neeley, M., Neill, C., Nersisyan, A., Newman, M., Ng, J. H., Nguyen, A., Nguyen, M., Niu, M. Y., OBrien, T. E., Opremcak, A., Petukhov, A., Potter, R., Pryadko, L. P., Quintana, C., Rocque, C., Rubin, N. C., Saei, N., Sank, D., Sankaragomathi, K., Satzinger, K. J., Schurkus, H. F., Schuster, C., Shearn, M. J., Shorter, A., Shutty, N., Shvarts, V., Skruzny, J., Smith, W. C., Somma, R., Sterling, G., Strain, D., Szalay, M., Torres, A., Vidal, G., Villalonga, B., Heidweiller, C. V., White, T., Woo, B. W. K., Xing, C., Yao, Z. J., Yeh, P., Yoo, J., Young, G., Zalcman, A., Zhang, Y., Zhu, N., Zobrist, N., Neven, H., Babbush, R., Bacon, D., Boixo, S., Hilton, J., Lucero, E., Megrant, A., Kelly, J., Chen, Y., Roushan, P., Smelyanskiy, V., and Abanin, D. A.

Subjects
Quantum Physics
Abstract

Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

Published
2023
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3. Phase transition in Random Circuit Sampling

Author

Morvan, A., Villalonga, B., Mi, X., Mandrà, S., Bengtsson, A., Klimov, P. V., Chen, Z., Hong, S., Erickson, C., Drozdov, I. K., Chau, J., Laun, G., Movassagh, R., Asfaw, A., Brandão, L. T. A. N., Peralta, R., Abanin, D., Acharya, R., Allen, R., Andersen, T. I., Anderson, K., Ansmann, M., Arute, F., Arya, K., Atalaya, J., Bardin, J. C., Bilmes, A., Bortoli, G., Bourassa, A., Bovaird, J., Brill, L., Broughton, M., Buckley, B. B., Buell, D. A., Burger, T., Burkett, B., Bushnell, N., Campero, J., Chang, H. S., Chiaro, B., Chik, D., Chou, C., Cogan, J., Collins, R., Conner, P., Courtney, W., Crook, A. L., Curtin, B., Debroy, D. M., Barba, A. Del Toro, Demura, S., Di Paolo, A., Dunsworth, A., Faoro, L., Farhi, E., Fatemi, R., Ferreira, V. S., Burgos, L. Flores, Forati, E., Fowler, A. G., Foxen, B., Garcia, G., Genois, E., Giang, W., Gidney, C., Gilboa, D., Giustina, M., Gosula, R., Dau, A. Grajales, Gross, J. A., Habegger, S., Hamilton, M. C., Hansen, M., Harrigan, M. P., Harrington, S. D., Heu, P., Hoffmann, M. R., Huang, T., Huff, A., Huggins, W. J., Ioffe, L. B., Isakov, S. V., Iveland, J., Jeffrey, E., Jiang, Z., Jones, C., Juhas, P., Kafri, D., Khattar, T., Khezri, M., Kieferová, M., Kim, S., Kitaev, A., Klots, A. R., Korotkov, A. N., Kostritsa, F., Kreikebaum, J. M., Landhuis, D., Laptev, P., Lau, K. -M., Laws, L., Lee, J., Lee, K. W., Lensky, Y. D., Lester, B. J., Lill, A. T., Liu, W., Livingston, W. P., Locharla, A., Malone, F. D., Martin, O., Martin, S., McClean, J. R., McEwen, M., Miao, K. C., Mieszala, A., Montazeri, S., Mruczkiewicz, W., Naaman, O., Neeley, M., Neill, C., Nersisyan, A., Newman, M., Ng, J. H., Nguyen, A., Nguyen, M., Niu, M. Yuezhen, O'Brien, T. E., Omonije, S., Opremcak, A., Petukhov, A., Potter, R., Pryadko, L. P., Quintana, C., Rhodes, D. M., Rosenberg, E., Rocque, C., Roushan, P., Rubin, N. C., Saei, N., Sank, D., Sankaragomathi, K., Satzinger, K. J., Schurkus, H. F., Schuster, C., Shearn, M. J., Shorter, A., Shutty, N., Shvarts, V., Sivak, V., Skruzny, J., Smith, W. C., Somma, R. D., Sterling, G., Strain, D., Szalay, M., Thor, D., Torres, A., Vidal, G., Heidweiller, C. Vollgraff, White, T., Woo, B. W. K., Xing, C., Yao, Z. J., Yeh, P., Yoo, J., Young, G., Zalcman, A., Zhang, Y., Zhu, N., Zobrist, N., Rieffel, E. G., Biswas, R., Babbush, R., Bacon, D., Hilton, J., Lucero, E., Neven, H., Megrant, A., Kelly, J., Aleiner, I., Smelyanskiy, V., Kechedzhi, K., Chen, Y., and Boixo, S.

Subjects
Quantum Physics
Abstract

Undesired coupling to the surrounding environment destroys long-range correlations on quantum processors and hinders the coherent evolution in the nominally available computational space. This incoherent noise is an outstanding challenge to fully leverage the computation power of near-term quantum processors. It has been shown that benchmarking Random Circuit Sampling (RCS) with Cross-Entropy Benchmarking (XEB) can provide a reliable estimate of the effective size of the Hilbert space coherently available. The extent to which the presence of noise can trivialize the outputs of a given quantum algorithm, i.e. making it spoofable by a classical computation, is an unanswered question. Here, by implementing an RCS algorithm we demonstrate experimentally that there are two phase transitions observable with XEB, which we explain theoretically with a statistical model. The first is a dynamical transition as a function of the number of cycles and is the continuation of the anti-concentration point in the noiseless case. The second is a quantum phase transition controlled by the error per cycle; to identify it analytically and experimentally, we create a weak link model which allows varying the strength of noise versus coherent evolution. Furthermore, by presenting an RCS experiment with 67 qubits at 32 cycles, we demonstrate that the computational cost of our experiment is beyond the capabilities of existing classical supercomputers, even when accounting for the inevitable presence of noise. Our experimental and theoretical work establishes the existence of transitions to a stable computationally complex phase that is reachable with current quantum processors.

Published
2023
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4. Purification-based quantum error mitigation of pair-correlated electron simulations

Author

O'Brien, T. E., Anselmetti, G., Gkritsis, F., Elfving, V. E., Polla, S., Huggins, W. J., Oumarou, O., Kechedzhi, K., Abanin, D., Acharya, R., Aleiner, I., Allen, R., Andersen, T. I., Anderson, K., Ansmann, M., Arute, F., Arya, K., Asfaw, A., Atalaya, J., Bacon, D., Bardin, J. C., Bengtsson, A., Boixo, S., Bortoli, G., Bourassa, A., Bovaird, J., Brill, L., Broughton, M., Buckley, B., Buell, D. A., Burger, T., Burkett, B., Bushnell, N., Campero, J., Chen, Y., Chen, Z., Chiaro, B., Chik, D., Cogan, J., Collins, R., Conner, P., Courtney, W., Crook, A. L., Curtin, B., Debroy, D. M., Demura, S., Drozdov, I., Dunsworth, A., Erickson, C., Faoro, L., Farhi, E., Fatemi, R., Ferreira, V. S., Burgos, L. Flores, Forati, E., Fowler, A. G., Foxen, B., Giang, W., Gidney, C., Gilboa, D., Giustina, M., Gosula, R., Dau, A. Grajales, Gross, J. A., Habegger, S., Hamilton, M. C., Hansen, M., Harrigan, M. P., Harrington, S. D., Heu, P., Hilton, J., Hoffmann, M. R., Hong, S., Huang, T., Huff, A., Ioffe, L. B., Isakov, S. V., Iveland, J., Jeffrey, E., Jiang, Z., Jones, C., Juhas, P., Kafri, D., Kelly, J., Khattar, T., Khezri, M., Kieferová, M., Kim, S., Klimov, P. V., Klots, A. R., Kothari, R., Korotkov, A. N., Kostritsa, F., Kreikebaum, J. M., Landhuis, D., Laptev, P., Lau, K., Laws, L., Lee, J., Lee, K., Lester, B. J., Lill, A. T., Liu, W., Livingston, W. P., Locharla, A., Lucero, E., Malone, F. D., Mandra, S., Martin, O., Martin, S., McClean, J. R., McCourt, T., McEwen, M., Megrant, A., Mi, X., Mieszala, A., Miao, K. C., Mohseni, M., Montazeri, S., Morvan, A., Movassagh, R., Mruczkiewicz, W., Naaman, O., Neeley, M., Neill, C., Nersisyan, A., Neven, H., Newman, M., Ng, J. H., Nguyen, A., Nguyen, M., Niu, M. Y., Omonije, S., Opremcak, A., Petukhov, A., Potter, R., Pryadko, L. P., Quintana, C., Rocque, C., Roushan, P., Saei, N., Sank, D., Sankaragomathi, K., Satzinger, K. J., Schurkus, H. F., Schuster, C., Shearn, M. J., Shorter, A., Shutty, N., Shvarts, V., Skruzny, J., Smelyanskiy, V., Smith, W. C., Somma, R., Sterling, G., Strain, D., Szalay, M., Thor, D., Torres, A., Vidal, G., Villalonga, B., Heidweiller, C. Vollgraff, White, T., Woo, B. W. K., Xing, C., Yao, Z. J., Yeh, P., Yoo, J., Young, G., Zalcman, A., Zhang, Y., Zhu, N., Zobrist, N., Gogolin, C., Babbush, R., and Rubin, N. C.

Subjects
Quantum Physics
Abstract

An important measure of the development of quantum computing platforms has been the simulation of increasingly complex physical systems. Prior to fault-tolerant quantum computing, robust error mitigation strategies are necessary to continue this growth. Here, we study physical simulation within the seniority-zero electron pairing subspace, which affords both a computational stepping stone to a fully correlated model, and an opportunity to validate recently introduced ``purification-based'' error-mitigation strategies. We compare the performance of error mitigation based on doubling quantum resources in time (echo verification) or in space (virtual distillation), on up to $20$ qubits of a superconducting qubit quantum processor. We observe a reduction of error by one to two orders of magnitude below less sophisticated techniques (e.g. post-selection); the gain from error mitigation is seen to increase with the system size. Employing these error mitigation strategies enables the implementation of the largest variational algorithm for a correlated chemistry system to-date. Extrapolating performance from these results allows us to estimate minimum requirements for a beyond-classical simulation of electronic structure. We find that, despite the impressive gains from purification-based error mitigation, significant hardware improvements will be required for classically intractable variational chemistry simulations., Comment: 10 pages, 13 page supplementary material, 12 figures. Experimental data available at https://doi.org/10.5281/zenodo.7225821

Published
2022
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5. Purification-based quantum error mitigation of pair-correlated electron simulations

Author

O’Brien, T. E., Anselmetti, G., Gkritsis, F., Elfving, V. E., Polla, S., Huggins, W. J., Oumarou, O., Kechedzhi, K., Abanin, D., Acharya, R., Aleiner, I., Allen, R., Andersen, T. I., Anderson, K., Ansmann, M., Arute, F., Arya, K., Asfaw, A., Atalaya, J., Bardin, J. C., Bengtsson, A., Bortoli, G., Bourassa, A., Bovaird, J., Brill, L., Broughton, M., Buckley, B., Buell, D. A., Burger, T., Burkett, B., Bushnell, N., Campero, J., Chen, Z., Chiaro, B., Chik, D., Cogan, J., Collins, R., Conner, P., Courtney, W., Crook, A. L., Curtin, B., Debroy, D. M., Demura, S., Drozdov, I., Dunsworth, A., Erickson, C., Faoro, L., Farhi, E., Fatemi, R., Ferreira, V. S., Flores Burgos, L., Forati, E., Fowler, A. G., Foxen, B., Giang, W., Gidney, C., Gilboa, D., Giustina, M., Gosula, R., Grajales Dau, A., Gross, J. A., Habegger, S., Hamilton, M. C., Hansen, M., Harrigan, M. P., Harrington, S. D., Heu, P., Hoffmann, M. R., Hong, S., Huang, T., Huff, A., Ioffe, L. B., Isakov, S. V., Iveland, J., Jeffrey, E., Jiang, Z., Jones, C., Juhas, P., Kafri, D., Khattar, T., Khezri, M., Kieferová, M., Kim, S., Klimov, P. V., Klots, A. R., Korotkov, A. N., Kostritsa, F., Kreikebaum, J. M., Landhuis, D., Laptev, P., Lau, K.-M., Laws, L., Lee, J., Lee, K., Lester, B. J., Lill, A. T., Liu, W., Livingston, W. P., Locharla, A., Malone, F. D., Mandrà, S., Martin, O., Martin, S., McClean, J. R., McCourt, T., McEwen, M., Mi, X., Mieszala, A., Miao, K. C., Mohseni, M., Montazeri, S., Morvan, A., Movassagh, R., Mruczkiewicz, W., Naaman, O., Neeley, M., Neill, C., Nersisyan, A., Newman, M., Ng, J. H., Nguyen, A., Nguyen, M., Niu, M. Y., Omonije, S., Opremcak, A., Petukhov, A., Potter, R., Pryadko, L. P., Quintana, C., Rocque, C., Roushan, P., Saei, N., Sank, D., Sankaragomathi, K., Satzinger, K. J., Schurkus, H. F., Schuster, C., Shearn, M. J., Shorter, A., Shutty, N., Shvarts, V., Skruzny, J., Smith, W. C., Somma, R. D., Sterling, G., Strain, D., Szalay, M., Thor, D., Torres, A., Vidal, G., Villalonga, B., Vollgraff Heidweiller, C., White, T., Woo, B. W. K., Xing, C., Yao, Z. J., Yeh, P., Yoo, J., Young, G., Zalcman, A., Zhang, Y., Zhu, N., Zobrist, N., Bacon, D., Boixo, S., Chen, Y., Hilton, J., Kelly, J., Lucero, E., Megrant, A., Neven, H., Smelyanskiy, V., Gogolin, C., Babbush, R., and Rubin, N. C.

Published
2023
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6. Formation of robust bound states of interacting microwave photons

Author

Morvan, A, Andersen, TI, Mi, X, Neill, C, Petukhov, A, Kechedzhi, K, Abanin, DA, Michailidis, A, Acharya, R, Arute, F, Arya, K, Asfaw, A, Atalaya, J, Bardin, JC, Basso, J, Bengtsson, A, Bortoli, G, Bourassa, A, Bovaird, J, Brill, L, Broughton, M, Buckley, BB, Buell, DA, Burger, T, Burkett, B, Bushnell, N, Chen, Z, Chiaro, B, Collins, R, Conner, P, Courtney, W, Crook, AL, Curtin, B, Debroy, DM, Del Toro Barba, A, Demura, S, Dunsworth, A, Eppens, D, Erickson, C, Faoro, L, Farhi, E, Fatemi, R, Flores Burgos, L, Forati, E, Fowler, AG, Foxen, B, Giang, W, Gidney, C, Gilboa, D, Giustina, M, Grajales Dau, A, Gross, JA, Habegger, S, Hamilton, MC, Harrigan, MP, Harrington, SD, Hoffmann, M, Hong, S, Huang, T, Huff, A, Huggins, WJ, Isakov, SV, Iveland, J, Jeffrey, E, Jiang, Z, Jones, C, Juhas, P, Kafri, D, Khattar, T, Khezri, M, Kieferová, M, Kim, S, Kitaev, AY, Klimov, PV, Klots, AR, Korotkov, AN, Kostritsa, F, Kreikebaum, JM, Landhuis, D, Laptev, P, Lau, K-M, Laws, L, Lee, J, Lee, KW, Lester, BJ, Lill, AT, Liu, W, Locharla, A, Malone, F, Martin, O, McClean, JR, McEwen, M, Meurer Costa, B, Miao, KC, Mohseni, M, Montazeri, S, Mount, E, Mruczkiewicz, W, Naaman, O, and Neeley, M

Subjects
Quantum Physics, Physical Sciences, Photons, Microwaves, Electrons, Fees and Charges, Reproduction, General Science & Technology
Abstract

Systems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles1. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multiparticle bound states2-9. Here we develop a high-fidelity parameterizable fSim gate and implement the periodic quantum circuit of the spin-½ XXZ model in a ring of 24 superconducting qubits. We study the propagation of these excitations and observe their bound nature for up to five photons. We devise a phase-sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the idea that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Published
2022

7. Realizing topologically ordered states on a quantum processor

Author

Satzinger, K. J., Liu, Y., Smith, A., Knapp, C., Newman, M., Jones, C., Chen, Z., Quintana, C., Mi, X., Dunsworth, A., Gidney, C., Aleiner, I., Arute, F., Arya, K., Atalaya, J., Babbush, R., Bardin, J. C., Barends, R., Basso, J., Bengtsson, A., Bilmes, A., Broughton, M., Buckley, B. B., Buell, D. A., Burkett, B., Bushnell, N., Chiaro, B., Collins, R., Courtney, W., Demura, S., Derk, A. R., Eppens, D., Erickson, C., Farhi, E., Foaro, L., Fowler, A. G., Foxen, B., Giustina, M., Greene, A., Gross, J. A., Harrigan, M. P., Harrington, S. D., Hilton, J., Hong, S., Huang, T., Huggins, W. J., Ioffe, L. B., Isakov, S. V., Jeffrey, E., Jiang, Z., Kafri, D., Kechedzhi, K., Khattar, T., Kim, S., Klimov, P. V., Korotkov, A. N., Kostritsa, F., Landhuis, D., Laptev, P., Locharla, A., Lucero, E., Martin, O., McClean, J. R., McEwen, M., Miao, K. C., Mohseni, M., Montazeri, S., Mruczkiewicz, W., Mutus, J., Naaman, O., Neeley, M., Neill, C., Niu, M. Y., O'Brien, T. E., Opremcak, A., Pató, B., Petukhov, A., Rubin, N. C., Sank, D., Shvarts, V., Strain, D., Szalay, M., Villalonga, B., White, T. C., Yao, Z., Yeh, P., Yoo, J., Zalcman, A., Neven, H., Boixo, S., Megrant, A., Chen, Y., Kelly, J., Smelyanskiy, V., Kitaev, A., Knap, M., Pollmann, F., and Roushan, P.

Subjects
Quantum Physics, Condensed Matter - Strongly Correlated Electrons
Abstract

The discovery of topological order has revolutionized the understanding of quantum matter in modern physics and provided the theoretical foundation for many quantum error correcting codes. Realizing topologically ordered states has proven to be extremely challenging in both condensed matter and synthetic quantum systems. Here, we prepare the ground state of the toric code Hamiltonian using an efficient quantum circuit on a superconducting quantum processor. We measure a topological entanglement entropy near the expected value of $\ln2$, and simulate anyon interferometry to extract the braiding statistics of the emergent excitations. Furthermore, we investigate key aspects of the surface code, including logical state injection and the decay of the non-local order parameter. Our results demonstrate the potential for quantum processors to provide key insights into topological quantum matter and quantum error correction., Comment: 6 pages 4 figures, plus supplementary materials

Published
2021
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8. Hepatocellular carcinoma radiation segmentectomy treatment intensification prior to liver transplantation increases rates of complete pathologic necrosis: an explant analysis of 75 tumors

Author

Montazeri, S. Ali, De la Garza-Ramos, Cynthia, Lewis, Andrew R., Lewis, Jason T., LeGout, Jordan D., Sella, David M., Paz-Fumagalli, Ricardo, Devcic, Zlatko, Ritchie, Charles A., Frey, Gregory T., Vidal, Lucas, Croome, Kristopher P., McKinney, J. Mark, Harnois, Denise, Krishnan, Sunil, Patel, Tushar, and Toskich, Beau B.

Published
2022
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9. Radiation Segmentectomy for the Treatment of Solitary Hepatocellular Carcinoma: Outcomes Compared with Those of Surgical Resection

Author

De la Garza-Ramos, Cynthia, Montazeri, S. Ali, Croome, Kristopher P., LeGout, Jordan D., Sella, David M., Cleary, Sean, Burns, Justin, Mathur, Amit K., Overfield, Cameron J., Frey, Gregory T., Lewis, Andrew R., Paz-Fumagalli, Ricardo, Ritchie, Charles A., McKinney, J. Mark, Mody, Kabir, Patel, Tushar, Devcic, Zlatko, and Toskich, Beau B.

Published
2022
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15. Clinical Efficacy of Transurethral Resection of the Prostate Combined with Oral Anticholinergics or Botulinum Toxin – A Injection to Treat Benign Prostatic Hyperplasia with Overactive Bladder: A Case–Control Study

Author

Allameh F, Basiri A, Razzaghi M, Abedi A, Fallah-karkan M, Ghiasy S, Hosseininia SM, and Montazeri S

Subjects
anticholinergic drug, benign prostatic hyperplasia, botulinum toxin-a, over active bladder, solifenacin, turp, Therapeutics. Pharmacology, RM1-950
Abstract

Farzad Allameh,1 Abbas Basiri,1 Mohammadreza Razzaghi,2 Amir reza Abedi,3 Morteza Fallah-karkan,2,3 Saleh Ghiasy,3 Seyyed Mohammad Hosseininia,3 Saeed Montazeri3 1Urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Laser Application in Medical Sciences Research Center, Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 3Department of Urology, Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, IranCorrespondence: Saeed MontazeriUrology Resident, Shohada E Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, IranTel +98 21 22749221Email saeed.montazeri89@gmail.comIntroduction: Recent investigations showed that anticholinergic drugs could use for the management of storage symptoms after transurethral resection of the prostate (TURP). The use of intravesical botulinum toxin-A (BTX-A) for the management of overactive bladder is rapidly increasing. In this research, we assess the efficacy of BTX-A vs solifenacin in men suffering from bladder outlet obstruction–over active bladder (BOO-OAB) managed with TURP.Methods: In this case–control study, 50 men with BOO-OAB randomized into two groups. The control group (A) underwent TURP and subsequently managed by solifenacin 5 mg daily, and the case group (B) underwent TURP and BTX-A injection in the bladder wall in the same session. Treatment success was the primary outcome and defined as post-injection improvement in the storage score of the International Prostate Symptom Score (IPSS) from baseline.Results: The IPSS, post-void residual volume, frequency, incomplete emptying, nocturia and urgency subscores considerably ameliorated after 12 weeks and 36 weeks for both groups, but it was more significant in the case arm. The quality of life (QoL) scores significantly improved after the treatments in both groups. Intervention group showed significant reductions regarding urgency incontinence compared with the solifenacin group at 12th and 36th weeks.Conclusion: BTX-A is an effective and well-tolerated treatment in patients with benign prostatic hyperplasia (BPH) who are candidates of TURP and simultaneously suffer from OAB symptoms.Keywords: anticholinergic drug, benign prostatic hyperplasia, botulinum toxin-A, over active bladder, solifenacin, TURP

Published
2020

18. Outcomes of Radiation Segmentectomy for Hepatocellular Carcinoma in Patients with Non-Alcoholic Fatty Liver Disease versus Chronic Viral Hepatitis

Author

De la Garza-Ramos, Cynthia, primary, Montazeri, S Ali, additional, Musto, Kaitlyn R, additional, Kapp, Melissa D, additional, Lewis, Andrew R, additional, Frey, Gregory, additional, Paz-Fumagalli, Ricardo, additional, Ilyas, Sumera, additional, Harnois, Denise M, additional, Majeed, Umair, additional, Patel, Tushar, additional, and Toskich, Beau, additional

Published
2023
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19. Stable Quantum-Correlated Many Body States via Engineered Dissipation

Author

Mi, X., Michailidis, A. A., Shabani, S., Miao, K. C., Klimov, P. V., Lloyd, J., Rosenberg, E., Acharya, R., Aleiner, I., Andersen, T. I., Ansmann, M., Arute, F., Arya, K., Asfaw, A., Atalaya, J., Bardin, J. C., Bengtsson, A., Bortoli, G., Bourassa, A., Bovaird, J., Brill, L., Broughton, M., Buckley, B. B., Buell, D. A., Burger, T., Burkett, B., Bushnell, N., Chen, Z., Chiaro, B., Chik, D., Chou, C., Cogan, J., Collins, R., Conner, P., Courtney, W., Crook, A. L., Curtin, B., Dau, A. G., Debroy, D. M., Barba, A. Del Toro, Demura, S., Di Paolo, A., Drozdov, I. K., Dunsworth, A., Erickson, C., Faoro, L., Farhi, E., Fatemi, R., Ferreira, V. S., Forati, L. F. Burgos E., Fowler, A. G., Foxen, B., Genois, E., Giang, W., Gidney, C., Gilboa, D., Giustina, M., Gosula, R., Gross, J. A., Habegger, S., Hamilton, M. C., Hansen, M., Harrigan, M. P., Harrington, S. D., Heu, P., Hoffmann, M. R., Hong, S., Huang, T., Huff, A., Huggins, W. J., Ioffe, L. B., Isakov, S. V., Iveland, J., Jeffrey, E., Jiang, Z., Jones, C., Juhas, P., Kafri, D., Kechedzhi, K., Khattar, T., Khezri, M., Kieferova, M., Kim, S., Kitaev, A., Klots, A. R., Korotkov, A. N., Kostritsa, F., Kreikebaum, J. M., Landhuis, D., Laptev, P., Lau, K. -M., Laws, L., Lee, J., Lee, K. W., Lensky, Y. D., Lester, B. J., Lill, A. T., Liu, W., Locharla, A., Malone, F. D., Martin, O., McClean, J. R., McEwen, M., Mieszala, A., Montazeri, S., Morvan, A., Movassagh, R., Mruczkiewicz, W., Neeley, M., Neill, C., Nersisyan, A., Newman, M., Ng, J. H., Nguyen, A., Nguyen, M., Niu, M. Y., OBrien, T. E., Opremcak, A., Petukhov, A., Potter, R., Pryadko, L. P., Quintana, C., Rocque, C., Rubin, N. C., Saei, N., Sank, D., Sankaragomathi, K., Satzinger, K. J., Schurkus, H. F., Schuster, C., Shearn, M. J., Shorter, A., Shutty, N., Shvarts, V., Skruzny, J., Smith, W. C., Somma, R., Sterling, G., Strain, D., Szalay, M., Torres, A., Vidal, G., Villalonga, B., Heidweiller, C. V., White, T., Woo, B. W. K., Xing, C., Yao, Z. J., Yeh, P., Yoo, J., Young, G., Zalcman, A., Zhang, Y., Zhu, N., Zobrist, N., Neven, H., Babbush, R., Bacon, D., Boixo, S., Hilton, J., Lucero, E., Megrant, A., Kelly, J., Chen, Y., Roushan, P., Smelyanskiy, V., and Abanin, D. A.

Subjects
Quantum Physics, FOS: Physical sciences, Quantum Physics (quant-ph)
Abstract

Engineered dissipative reservoirs can steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using 49 superconducting qubits, we prepare low-energy states of the transverse-field Ising model via coupling to dissipative auxiliary qubits. In 1D, we observe long-range quantum correlations and a ground state fidelity that depends weakly on system sizes. In 2D, we find mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we discover a new spin transport regime in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors, and an essential tool for investigating nonequilibrium quantum phenomena.

Published
2023

20. Noise-resilient edge modes on a chain of superconducting qubits

Author

Mi, X., primary, Sonner, M., additional, Niu, M. Y., additional, Lee, K. W., additional, Foxen, B., additional, Acharya, R., additional, Aleiner, I., additional, Andersen, T. I., additional, Arute, F., additional, Arya, K., additional, Asfaw, A., additional, Atalaya, J., additional, Bardin, J. C., additional, Basso, J., additional, Bengtsson, A., additional, Bortoli, G., additional, Bourassa, A., additional, Brill, L., additional, Broughton, M., additional, Buckley, B. B., additional, Buell, D. A., additional, Burkett, B., additional, Bushnell, N., additional, Chen, Z., additional, Chiaro, B., additional, Collins, R., additional, Conner, P., additional, Courtney, W., additional, Crook, A. L., additional, Debroy, D. M., additional, Demura, S., additional, Dunsworth, A., additional, Eppens, D., additional, Erickson, C., additional, Faoro, L., additional, Farhi, E., additional, Fatemi, R., additional, Flores, L., additional, Forati, E., additional, Fowler, A. G., additional, Giang, W., additional, Gidney, C., additional, Gilboa, D., additional, Giustina, M., additional, Dau, A. G., additional, Gross, J. A., additional, Habegger, S., additional, Harrigan, M. P., additional, Hoffmann, M., additional, Hong, S., additional, Huang, T., additional, Huff, A., additional, Huggins, W. J., additional, Ioffe, L. B., additional, Isakov, S. V., additional, Iveland, J., additional, Jeffrey, E., additional, Jiang, Z., additional, Jones, C., additional, Kafri, D., additional, Kechedzhi, K., additional, Khattar, T., additional, Kim, S., additional, Kitaev, A. Y., additional, Klimov, P. V., additional, Klots, A. R., additional, Korotkov, A. N., additional, Kostritsa, F., additional, Kreikebaum, J. M., additional, Landhuis, D., additional, Laptev, P., additional, Lau, K.-M., additional, Lee, J., additional, Laws, L., additional, Liu, W., additional, Locharla, A., additional, Martin, O., additional, McClean, J. R., additional, McEwen, M., additional, Meurer Costa, B., additional, Miao, K. C., additional, Mohseni, M., additional, Montazeri, S., additional, Morvan, A., additional, Mount, E., additional, Mruczkiewicz, W., additional, Naaman, O., additional, Neeley, M., additional, Neill, C., additional, Newman, M., additional, O’Brien, T. E., additional, Opremcak, A., additional, Petukhov, A., additional, Potter, R., additional, Quintana, C., additional, Rubin, N. C., additional, Saei, N., additional, Sank, D., additional, Sankaragomathi, K., additional, Satzinger, K. J., additional, Schuster, C., additional, Shearn, M. J., additional, Shvarts, V., additional, Strain, D., additional, Su, Y., additional, Szalay, M., additional, Vidal, G., additional, Villalonga, B., additional, Vollgraff-Heidweiller, C., additional, White, T., additional, Yao, Z., additional, Yeh, P., additional, Yoo, J., additional, Zalcman, A., additional, Zhang, Y., additional, Zhu, N., additional, Neven, H., additional, Bacon, D., additional, Hilton, J., additional, Lucero, E., additional, Babbush, R., additional, Boixo, S., additional, Megrant, A., additional, Chen, Y., additional, Kelly, J., additional, Smelyanskiy, V., additional, Abanin, D. A., additional, and Roushan, P., additional

Published
2022
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22. Abstract No. 197 Predictors of complete pathologic necrosis in hepatocellular carcinoma treated with yttrium-90 radiation segmentectomy prior to liver transplantation: an explant analysis of 75 tumors

Author

Montazeri, S., primary, De la Garza-Ramos, C., additional, Lewis, A., additional, Lewis, J., additional, LeGout, J., additional, Sella, D., additional, Paz-Fumagalli, R., additional, Devcic, Z., additional, Ritchie, C., additional, Frey, G., additional, Vidal, L., additional, McKinney, J., additional, and Toskich, B., additional

Published
2022
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26. Correlation between anthropometric indices at birth and developmental delay in children aged 4–60 months in Isfahan, Iran

Author

Amir Ali Akbari S, Montazeri S, Torabi F, Amiri S, Soleimani F, and Alavi Majd H

Subjects
Medicine (General), R5-920
Abstract

S Amir Ali Akbari,1 S Montazeri,2 F Torabi,3 S Amiri,3 F Soleimani,4 H Alavi Majd51Department of Midwifery, Faculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Reproductive Health, British Columbia, Canada; 3Faculty of Nursing and Midwifery, Shahid Beheshti, University of Medical Sciences, Tehran, Iran; 4Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran; 5Department of Biostatistics, Faculty of Paramedical, Shahid Beheshti University of Medical Sciences, Tehran, IranBackground: Advances in medical knowledge and treatment modalities have resulted in an increased survival rate for high-risk infants. This increased number of survivors enables study of the future development of these children. Other than infection and trauma, developmental and behavioral problems are the most common medical problems among such children. This study sought correlations between anthropometric indices at birth and developmental delay in children aged 4–60 months who visited health service centers affiliated with the Isfahan University of Medical Sciences in 2010.Methods: In this descriptive, correlational study, 401 children aged 4–60 months and visiting health service centers were selected using a multistage method. Anthropometric indices at birth were collected from their health care records, and developmental status was measured using the Ages and Stages Questionnaire, the validity (0.84) and reliability (0.94) of which were obtained from a previous study.Results: The mean age of the children in the normal group was 17.33 ± 13.18 months and that in the developmental delay group was 29.92 ± 19.19 months. Most children in the normal group were female (56%) and in the developmental delay group were male (55.2%). No correlation was found between height and head circumference at birth and developmental delay. However, the birth weight of children with developmental delay was four times lower than that of children with normal development (P = 0.004, odds ratio 4).Conclusion: Birth weight and male gender were factors that strongly correlated with developmental delay in this study.Keywords: anthropometric indices, developmental delay, children

Published
2012

27. Realizing topologically ordered states on a quantum processor

Author

Satzinger, K. J., primary, Liu, Y.-J, additional, Smith, A., additional, Knapp, C., additional, Newman, M., additional, Jones, C., additional, Chen, Z., additional, Quintana, C., additional, Mi, X., additional, Dunsworth, A., additional, Gidney, C., additional, Aleiner, I., additional, Arute, F., additional, Arya, K., additional, Atalaya, J., additional, Babbush, R., additional, Bardin, J. C., additional, Barends, R., additional, Basso, J., additional, Bengtsson, A., additional, Bilmes, A., additional, Broughton, M., additional, Buckley, B. B., additional, Buell, D. A., additional, Burkett, B., additional, Bushnell, N., additional, Chiaro, B., additional, Collins, R., additional, Courtney, W., additional, Demura, S., additional, Derk, A. R., additional, Eppens, D., additional, Erickson, C., additional, Faoro, L., additional, Farhi, E., additional, Fowler, A. G., additional, Foxen, B., additional, Giustina, M., additional, Greene, A., additional, Gross, J. A., additional, Harrigan, M. P., additional, Harrington, S. D., additional, Hilton, J., additional, Hong, S., additional, Huang, T., additional, Huggins, W. J., additional, Ioffe, L. B., additional, Isakov, S. V., additional, Jeffrey, E., additional, Jiang, Z., additional, Kafri, D., additional, Kechedzhi, K., additional, Khattar, T., additional, Kim, S., additional, Klimov, P. V., additional, Korotkov, A. N., additional, Kostritsa, F., additional, Landhuis, D., additional, Laptev, P., additional, Locharla, A., additional, Lucero, E., additional, Martin, O., additional, McClean, J. R., additional, McEwen, M., additional, Miao, K. C., additional, Mohseni, M., additional, Montazeri, S., additional, Mruczkiewicz, W., additional, Mutus, J., additional, Naaman, O., additional, Neeley, M., additional, Neill, C., additional, Niu, M. Y., additional, O’Brien, T. E., additional, Opremcak, A., additional, Pató, B., additional, Petukhov, A., additional, Rubin, N. C., additional, Sank, D., additional, Shvarts, V., additional, Strain, D., additional, Szalay, M., additional, Villalonga, B., additional, White, T. C., additional, Yao, Z., additional, Yeh, P., additional, Yoo, J., additional, Zalcman, A., additional, Neven, H., additional, Boixo, S., additional, Megrant, A., additional, Chen, Y., additional, Kelly, J., additional, Smelyanskiy, V., additional, Kitaev, A., additional, Knap, M., additional, Pollmann, F., additional, and Roushan, P., additional

Published
2021
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29. Biochemical Safety of Ablative Yttrium-90 Radioembolization for Hepatocellular Carcinoma as a Function of Percent Liver Treated

Author

De la Garza-Ramos, Cynthia, primary, Overfield, Cameron J, additional, Montazeri, S Ali, additional, Liou, Harris, additional, Paz-Fumagalli, Ricardo, additional, Frey, Gregory T, additional, McKinney, J Mark, additional, Ritchie, Charles A, additional, Devcic, Zlatko, additional, Lewis, Andrew R, additional, Harnois, Denise M, additional, Patel, Tushar, additional, and Toskich, Beau B, additional

Published
2021
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31. What Can We Perceive In Infant Vocalization?

Author

Spear J, Zeng J, Beyak A, Joshi J, Jain B, Cook Mt, Smith B, Martin S, Cressman C, Mielniczek M, Thompson T, Montazeri S, Soderstrom M, Sawatzky J, Perera E, Cadieux O, and Trudel D

Subjects
Communication, Infant Vocalization, business.industry, business, Psychology
Abstract

Infant language development includes a complex social dynamic between adults and infants. Infant vocalization is a well-studied area of development, however adult perception of infant vocalization is less well-understood. The effectiveness of identifications made by adults may impact the social feedback loops that drive development. We collected data from a final sample of 460 undergraduate students who listened to brief (100-500) ms audio clips of infant vocalization. Participants were asked to identify infants in the audio clips as male/female, English/non-English, and their approximate age. Participants were unable to determine the sex of the infant better than chance but showed better than chance performance for language and age, albeit with low accuracy. Exploratory follow-up analyses did not reveal an effect of caregiving experience, childcare experience, or participant gender on a participants’ ability to correctly identify the infant’s age or language. These findings suggest that adult caregivers, regardless of experience, are able to perceive elements of infant vocalizations that may influence responsiveness to infant vocal development. However, performance is far from perfect.

Published
2020

32. Prognostic Significance of Neutrophil to Lymphocyte Ratio Dynamics in Patients with Hepatocellular Carcinoma Treated with Radioembolization Using Glass Microspheres

Author

Li, Xi, primary, Montazeri, S. Ali, additional, Paz-Fumagalli, Ricardo, additional, Padula, Carlos A., additional, Wang, Weiping, additional, Mody, Kabir, additional, Roberts, Lewis R., additional, Patel, Tushar, additional, Krishnan, Sunil, additional, and Toskich, Beau, additional

Published
2021
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37. Design and Implementation of a High-Precision Position Controller for Permanent Magnet Synchronous Motor Based on a New Gain Scheduling Approach.

Author

Montazeri, S. H., Aliabad, A. Damaki, Zareh, F., and Aghaei, S.

Subjects
SYNCHRONOUS electric motors, PID controllers, ELECTRIC inverters, ARM microprocessors, VECTOR control
Abstract

The direct drive permanent magnet synchronous motor (DD-PMSM) is a suitable choice for high-precision position control applications. Among various control methods of this motor, the vector control approaches especially the field oriented control has a highperformance in the industrial drives. In this method, the components of stator current are controlled independently and as a result, the torque and flux are controlled continuously. Since there are some limitations and constraints in the motor, inverter, and control system, a new anti-windup gain scheduling PID controller based on the adaptive control principles is proposed for the position control loop. In the proposed method, different values are assigned to coefficients of the PID controller according to the position error to achieve high precision. Also, a very high-accuracy encoder and an ARM processor are used for measuring the instantaneous position and implementation of the proposed method, respectively. The simulation and experimental results validate the effectiveness, high accuracy, and good dynamic behavior of the proposed control method. [ABSTRACT FROM AUTHOR]

Published
2021
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38. The Austempering Kinetics, Microstructural Development, and Processing Window in the Austempered, Fe-3.2C-4.8Al Compacted Graphite Cast Iron.

Author

Kazazi, A., Montazeri, S. M., and Boutorabi, S. M. A.

Subjects
CAST-iron, GRAPHITE, AUSTEMPERING (Heat treatment), IRON founding, ALUMINUM castings, BAINITE
Abstract

In the present study, austempering heat treatment was performed on compacted graphite aluminum cast iron with the chemical composition of 4.8 wt% Al, 3.2 wt% C, 0.81 wt% Ni, 0.37 wt% Mn, and 0.02 wt% Mg. This study aims to investigate the effect of aluminum additions and removal of silicon on the kinetics of austempering transformation of Fe-3.2%C alloy. The cast samples were austenitized at 900 °C for 120 min and the isothermal austempering heat treatment was performed at 200 °C, 300 °C, and 400 °C for 5, 30, 60, 120, and 180 minutes, respectively. The kinetics of this transformation was studied by X-ray diffraction (XRD) analysis. The effect of temperature and time on the microstructure and hardness of the austempered samples was investigated and discussed. The presence of Al was seen to the prolonged form of the carbides from high carbon austenite, and that expanded the process window in the austempering transformation. Besides, the lower bainitic ferrite phase was observed in the austempered samples at 200 °C and 300 °C. Increasing austempering temperature to 400 °C changed the lower bainite to the upper bainite structure. The volume fraction of austenite reached its maximum level (34.6 %) after austempering the samples at 400 °C for 30 minutes. [ABSTRACT FROM AUTHOR]

Published
2020
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41. Age-specific anti-Müllerian hormone and electrocardiographic silent coronary artery disease

Author

MS VPG/Gynaecologie, Circulatory Health, Child Health, Ramezani Tehrani, F., Montazeri, S. A., Khalili, D., Cheraghi, L., Broekmans, F. J., Momenan, A. A., de Kat, A. C., Azizi, F., MS VPG/Gynaecologie, Circulatory Health, Child Health, Ramezani Tehrani, F., Montazeri, S. A., Khalili, D., Cheraghi, L., Broekmans, F. J., Momenan, A. A., de Kat, A. C., and Azizi, F.

Published
2016

43. Expression of antigenic determinants of the haemagglutinin large subunit of novel influenza virus in insect cells

Author

Yousefi, A., Fotouhi, F., Samaneh Hosseinzadeh, Kheiri, M. T., Farahmand, B., Montazeri, S., Mousavi, F., Department of Cellular and Molecular Biology, West Tehran Islamic Azad University [Tehran] (WTIAU), Influenza Research Laboratory, Institut Pasteur d'Iran, and Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)

Subjects
viruses, Immunoblotting, Molecular Sequence Data, virus diseases, Hemagglutinin Glycoproteins, Influenza Virus, Sequence Analysis, DNA, Spodoptera, Transfection, complex mixtures, Recombinant Proteins, Cell Line, Epitopes, Influenza A Virus, H1N1 Subtype, Animals, Humans, [SDV.IMM.VAC]Life Sciences [q-bio]/Immunology/Vaccinology, Baculoviridae
Abstract

The global outbreak of novel A/H1N1 spread in human population worldwide has revealed an emergency need for producing a vaccine against this virus. Current influenza vaccines encounter problems with safety issues and weak response in high-risk population. It has been established that haemagglutinin is the most important viral antigen to which antibody responses are directed, and recombinant subunit vaccines, haemagglutinin of influenza A and B viruses, have been considered in order to facilitate vaccine production. In the present study, we have focused on construction of a recombinant baculovirus encoding the large subunit of novel influenza virus A/H1N1 haemagglutinin. The full genome of haemagglutinin was cloned into pGEM-TEasy vector and sequenced. The large subunit of the haemagglutinin gene was amplified by PCR using specific primers and cloned into pFast- BacHTc donor plasmid, which was then confirmed by restriction enzyme analysis and sequencing and transformed into E. coli DH10Bac competent cells. The bacmid DNA was transfected into insect cells to produce recombinant baculovirus. Expression of recombinant haemagglutinin in insect cells was determined by SDS-PAGE and immunoblotting. It has been shown that the recombinant haemagglutinin (rHA) obtained from the baculovirus insect cell expression system has suitable immunogenicity in human and can be considered as a candidate flu vac- cine. Here we produced large amounts of the HA1 protein of novel influenza A/H1N1 (Iranian isolate) in insect cells. The immunogenicity and efficacy of the recombinant HA1 will be evaluated as a vaccine candidate and compared to the recombinant HA1 produced in a prokaryotic system.

Published
2012

44. Incidence of isolation of Mycobacterium tuberculosis from blood samples in tuberculosis patients in Imam Khomeini Hospital, Tehran, Iran

Author

Foroughi, M., Montazeri, S. M., SeyedAhmad SeyedAlinaghi, Badie, B. M., Heiydarpour, P., Roosta, N., Rasoolinejad, M., and Cochak, H. E.

Subjects
lcsh:R5-920, Incidence, Humans, Tuberculosis, Immunity status, Mycobacterium tuberculosis, Iran, lcsh:Medicine (General)
Abstract

It is estimated that one third of the world's population is latently infected with tuberculosis (TB). The HIV epidemic fuels the TB epidemic by increasing the risk of reactivation of latent TB infection and by facilitating a more rapid progression of TB disease. Although the incidence of TB is constant or decreasing in many regions of the world, rates remain high in developing countries as a consequence of the HIV epidemic. This study was conducted as a collaboration of the Infectious Diseases department of Imam Khomeini Hospital with the Microbiology department of Tehran University of Medical Sciences. The hospital dataset of 94 patients admitted with TB during 2003-2005 was reviewed. We aimed to study factors correlating with positive blood culture including age, sex, immune deficiency status, HIV serology and SIRS (Systemic Inflammatory Response Syndrome) status. In this study, we found that positive blood cultures are more frequent in patients less than 45 years old. Positive blood cultures were also more frequent in HIV infected patients and there was a significant correlation between blood culture and SIRS status. Therefore, we recommend that we obtain blood cultures from these high-risk groups in order to increase early detection of TB.

Published
2011

45. The fusion of SAR tomography and Stereo-SAR for 3D absolute scatterer positioning

Author

Montazeri, S. (author) and Montazeri, S. (author)

Abstract

For decades, spaceborne Synthetic Aperture Radar (SAR) interferometry has evolved into a widely used geodetic method for three-dimensional mapping and analysing the geophysical processes of the surface of the earth. Nevertheless, effects such as atmospheric disturbances, temporal and geometric decorrelation are considered as the main degrading factors for the quality of Interferometric Synthetic Aperture Radar (InSAR) products. By overcoming the major deficiencies of the conventional InSAR, Persistent Scatterer Interferometry (PSI) proved the applicability of the interferometric methods also in monitoring of urban areas by restricting the analysis only on the time-coherent scatterers. In particular, the launch of modern SAR sensors, such as the German TerraSAR-X, characterized with very high spatial resolution and short revisit times has enhanced the capability of PSI in mapping and deformation monitoring of urban areas. However, PSI considers only a single dominant scatterer in each resolution cell which is not a valid assumption in urban areas due to the prevalent occurrences of layover phenomenon. This gives the motivation to exploit the most advanced SAR interferometric method, namely tomographic SAR inversion (TomoSAR) including SAR Tomography and differential SAR Tomography. TomoSAR coupled with very high resolution TerraSAR-X images produces the most detailed multi-dimensional maps of urban areas by distinguishing among multiple scatterers within a resolution cell. Nevertheless in TomoSAR, similar to conventional InSAR and PSI, elevation and deformation rates are estimated with respect to a previously chosen reference point which makes them relative 3D estimates. One unique feature of TerraSAR-X is the precise orbit determination and high geometrical localization accuracy of the sensor. After compensating for the most prominent geodynamics and atmospheric error sources, the absolute two-dimensional (range and azimuth) positions of targets such as corner refle, Geomatics, Geoscience and Remote Sensing, Civil Engineering and Geosciences

Published
2014

46. Modelling and observation of heat losses from buildings: The impact of geometric detail on 3D heat flux modelling

Author

Lee, D. (author), Pietrzyk, P. (author), Donkers, S. (author), Liem, V. (author), van Oostveen, J. (author), Montazeri, S. (author), Boeters, R. (author), Colin, J. (author), Kastendeuch, P. (author), Nerry, F. (author), Menenti, M. (author), Gorte, B.G.H. (author), Verbree, E. (author), Lee, D. (author), Pietrzyk, P. (author), Donkers, S. (author), Liem, V. (author), van Oostveen, J. (author), Montazeri, S. (author), Boeters, R. (author), Colin, J. (author), Kastendeuch, P. (author), Nerry, F. (author), Menenti, M. (author), Gorte, B.G.H. (author), and Verbree, E. (author)

Abstract

The impact of 3D geometry complexity on the accuracy of simulating radiative, convective and conductive fluxes in an urban canyon was explored. The research involved the collection of meteorological data in an urban canyon in the city of Strasbourg, France, for input into a 3D model called LASER/F, which simulates the aforementioned fluxes. The key input into LASER/F is a 3D geometric model representing the scene (urban canyon). It was hypothesized that more geometric detail in the model would lead to improved accuracy in the simulation but increased computing time. To test this, seven geometry scenarios were prepared with different complexities and test run in LASER/F. The results were validated with thermal images of two facades collected during the field campaign in Strasbourg. The results show that LASER/F systematically underestimates facade surface temperatures possibly due to various model assumptions and input geometry. One of those is the oversimplified 1D parameterization of the vertical wind profile and was demonstrated by comparing it with a vertical wind profile extracted from a CFD model. It was concluded that the most complex 3D geometry does not necessarily improve simulation accuracy, especially during warming periods of the day, but does affect simulation time. The inclusion of balconies on the facades is influential and should be used for future simulation experiments when it is a significant feature of a facade. This implies that 3D simulations for the management of urban heat at canyon scale will need to consider the particularities of facades on a case-by-case basis when determining level of detail required for the input geometry. Further research is required to better understand canyon geometry effects such as canyon orientation, aspect ratio and the volumetric influence on internal heat storage in buildings. The investigation was carried out in association with ICube Laboratory (UMR 7357 CNRS-Université de Strasbourg), for the 2012 Geomatics, Geoscience & Remote Sensing, Civil Engineering and Geosciences

Published
2013

48. The effect of 3D geometry complexity on simulating radiative, conductive and convective fluxes in an urban canyon

Author

Boeters, R. (author), Donkers, S. (author), Lee, D.J. (author), Liem, V. (author), Montazeri, S. (author), van Oostveen, J. (author), Pietrzyk, P. (author), Boeters, R. (author), Donkers, S. (author), Lee, D.J. (author), Liem, V. (author), Montazeri, S. (author), van Oostveen, J. (author), and Pietrzyk, P. (author)

Abstract

The Geomatics Synthesis Project (GSP) was an eight-week culminating group project by seven second-year MSc. Geomatics students. The objective was to undertake group and fieldwork through a real-world project with an external organization. In association with Laboratoire des Sciences de L'Image Informatique et Teledetection (LSIIT) at the University of Strasbourg, the 2012 GSP explored the impact of 3D geometry complexity on the accuracy of simulating radiative, convective and conductive fluxes in an urban canyon. The research involved the collection of meteorological data near the urban canyon in Strasbourg, France, for input into a model called LAtent, SEnsible, Radiation Fluxes (LASER/F), which simulates the aforementioned fluxes. The preparation of seven geometry scenarios with different complexities was completed and test run in LASER/F. The results were validated with thermal images of two facades collected during the field campaign in Strasbourg. The results show that LASER/F systematically underestimates facade surface temperatures due to various model assumptions. One of those is the oversimplified 1D parametrization of the wind and was demonstrated by comparing it with a vertical wind profile extracted from a Computational Fluid Dynamics (CFD) model. Nevertheless, it was concluded that the most complex 3D geometry does not necessarily improve simulation accuracy, especially during warming periods of the day. The inclusion of balconies on the facades is influential and should be used for future simulation experiments when it is a signifcant feature of the facade. Further research is required to better understand canyon geometry effects such as canyon orientation, aspect ratio and the volumetric influence on internal heat storage in buildings., Architecture and The Built Environment, OTB Research Institute for the Built Environment, Geomatics for the Built Environment

Published
2012

49. Correlation between anthropometric indices at birth and developmental delay in children aged 4–60 months in Isfahan, Iran

Author

Amir Ali Akbari,S, Montazeri,S, Torabi,F, Amiri,S, Soleimani,F, Alavi Majd,H, Amir Ali Akbari,S, Montazeri,S, Torabi,F, Amiri,S, Soleimani,F, and Alavi Majd,H

Abstract

S Amir Ali Akbari,1 S Montazeri,2 F Torabi,3 S Amiri,3 F Soleimani,4 H Alavi Majd51Department of Midwifery, Faculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Reproductive Health, British Columbia, Canada; 3Faculty of Nursing and Midwifery, Shahid Beheshti, University of Medical Sciences, Tehran, Iran; 4Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran; 5Department of Biostatistics, Faculty of Paramedical, Shahid Beheshti University of Medical Sciences, Tehran, IranBackground: Advances in medical knowledge and treatment modalities have resulted in an increased survival rate for high-risk infants. This increased number of survivors enables study of the future development of these children. Other than infection and trauma, developmental and behavioral problems are the most common medical problems among such children. This study sought correlations between anthropometric indices at birth and developmental delay in children aged 4–60 months who visited health service centers affiliated with the Isfahan University of Medical Sciences in 2010.Methods: In this descriptive, correlational study, 401 children aged 4–60 months and visiting health service centers were selected using a multistage method. Anthropometric indices at birth were collected from their health care records, and developmental status was measured using the Ages and Stages Questionnaire, the validity (0.84) and reliability (0.94) of which were obtained from a previous study.Results: The mean age of the children in the normal group was 17.33 ± 13.18 months and that in the developmental delay group was 29.92 ± 19.19 months. Most children in the normal group were female (56%) and in the developmental delay group were male (55.2%). No correlation was found between height and head circumference at birth and developmental delay. However, the birth weight of ch

Published
2012

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