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1. Thermodynamics of hybrid quantum rotor devices

Author

Leitch, Heather, Hammam, Kenza, and De Chiara, Gabriele

Subjects
Quantum Physics, Condensed Matter - Statistical Mechanics
Abstract

We investigate the thermodynamics of a hybrid quantum device consisting of two qubits collectively interacting with a quantum rotor and coupled dissipatively to two equilibrium reservoirs at different temperatures. By modelling the dynamics and the resulting steady state of the system using a collision model, we identify the functioning of the device as a thermal engine, a refrigerator or an accelerator. In addition, we also look into the device's capacity to operate as a heat rectifier, and optimise both the rectification coefficient and the heat flow simultaneously. Drawing an analogy to heat rectification and since we are interested in the conversion of energy into the rotor's kinetic energy, we introduce the concept of angular momentum rectification which may be employed to control work extraction through an external load., Comment: Close to the published version. Microscopic models updated

Published
2023
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2. Heat transport in quantum devices

Author

Leitch, Heather, De Chiara, Gabriele, and Paternostro, Mauro

Subjects
quantum thermodynamics, open quantum systems, continuous variables, collision model
Abstract

We use the theory of open quantum systems to study quantum thermal machines, deriving their master equations to understand how they evolve in time. We consider three different working substances coupled to heat baths that may act as engines, refrigerators, accelerators or dissipators. The first is a network of driven quantum harmonic oscillators where we study the effect that the driving speed has on the operation of the system. We see how squeezing one of the baths may lead to a more efficient engine as well as the generation of entanglement within the system. We then investigate the use of coherence in the baths as a resource to improve the performance of a quantum thermal machine whose working substance consists of a single qubit. Finally, we introduce a rotor to a system of two qubits to create an autonomous quantum machine capable of converting heat flow into useful mechanical work. We also study both the heat and angular momentum rectification that may be accomplished by this machine.

Published
2023

4. Exploiting coherence for quantum thermodynamic advantage

Author

Hammam, Kenza, Leitch, Heather, Hassouni, Yassine, and De Chiara, Gabriele

Subjects
Quantum Physics, Condensed Matter - Statistical Mechanics
Abstract

The introduction of the quantum analogue of a Carnot engine based on a bath comprising of particles with a small amount of coherence initiated an active line of research on the harnessing of different quantum resources for the enhancement of thermal machines beyond the standard reversible limit, with an emphasis on non-thermal baths containing quantum coherence. In our work, we investigate the impact of coherence on the thermodynamic tasks of a collision model which is composed of a system interacting, in the continuous time limit, with a series of coherent ancillas of two baths at different temperatures. Our results show the advantages of utilising coherence as a resource in the operation of the machine, and allows it: (i) to exhibit unconventional behaviour such as the appearance of a hybrid refrigerator, capable of simultaneous refrigeration and generation of work, and (ii) to function as an engine or a refrigerator with efficiencies larger than the Carnot bound. Moreover, we find an effective upper bound to the efficiency of the thermal machine operating as an engine in the presence of a coherent reservoir., Comment: Accepted version

Published
2022
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5. Driven quantum harmonic oscillators: A working medium for thermal machines

Author

Leitch, Heather, Piccione, Nicolò, Bellomo, Bruno, and De Chiara, Gabriele

Subjects
Quantum Physics, Condensed Matter - Statistical Mechanics
Abstract

The study of quantum thermodynamics is key to the development of quantum thermal machines. In contrast to most of the previous proposals based on discrete strokes, here we consider a working substance that is permanently coupled to two or more baths at different temperatures and continuously driven. To this end, we investigate parametrically driven quantum harmonic oscillators coupled to heat baths via a collision model. Using a thermodynamically consistent local master equation, we derive the heat flows and power of the working device which can operate as an engine, refrigerator or accelerator and analyze the instantaneous and average efficiencies and coefficients of performance. Studying the regimes of both slow and fast driving of the system, we find that an increased driving frequency can lead to a change of functioning to a dissipator. Finally, we investigate the effect of squeezing one of the thermal baths: it leads to an apparent higher efficiency compared to the corresponding Carnot value of an equilibrium bath with the same temperature and to sustained entanglement between the working substance oscillators in the limit cycle., Comment: Accepted version. See associated Scilight summary: https://doi.org/10.1063/10.0009575

Published
2021
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6. Phase 1 study of JNJ-64619178, a protein arginine methyltransferase 5 inhibitor, in patients with lower-risk myelodysplastic syndromes

Author

Haque, Tamanna, Cadenas, Felix López, Xicoy, Blanca, Alfonso-Pierola, Ana, Platzbecker, Uwe, Avivi, Irit, Brunner, Andrew M., Chromik, Jöerg, Morillo, Daniel, Patel, Manish R., Falantes, Jose, Leitch, Heather A., Germing, Ulrich, Preis, Meir, Lenox, Laurie, Lauring, Josh, Brown, Regina J., Kalota, Anna, Mehta, Jaydeep, Pastore, Friederike, Gu, Junchen, Mistry, Pankaj, and Valcárcel, David

Published
2023
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10. Improvement in quality of life in MDS patients who become transfusion independent after treatment.

Author

Wan, Bo A., Alibhai, Shabbir M. H., Chodirker, Lisa, Mozessohn, Lee, Geddes, Michelle, Zhu, Nancy, Trottier, Amy M., St-Hilaire, Eve, Finn, Nicholas, Leber, Brian, Khalaf, Dina, Christou, Grace, Sabloff, Mitchell, Leitch, Heather A., Shamy, April, Yee, Karen W. L., Storring, John, Nevill, Thomas J., Houston, Brett L., and Elemary, Mohamed

Subjects
MYELODYSPLASTIC syndromes, SOCIAL skills, QUALITY of life, ANEMIA
Abstract

Myelodysplastic syndromes (MDSs) treatment focuses on improving quality of life (QOL), affected by anemia and transfusion dependence (TD). Using the MDS-CAN registry, we studied how changes in transfusion status – TD to transfusion independence (TI) (group A), or vice versa (group B), and maintaining TD (group C) or TI (group D) – affected OS and QOL in 1120 MDS patients. Analysis showed superior OS for those remaining TI, poorer for those remaining TD, and intermediate for those with changes. Among 656 treated patients, group A (n = 54) showed improved QOL, with trends toward improved physical and social function scores. Group B (n = 151) experienced declines in global QOL measures after switching to TD, particularly in fatigue and physical, role, and social functioning. Group C had notable fatigue worsening, while group D showed milder declines across multiple QOL aspects. Achieving TI in MDS correlates with improved QOL, whereas reverting to TD more significantly worsens overall QOL and function scores. [ABSTRACT FROM AUTHOR]

Published
2025
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11. Differences in Physician Burnout by Specialty: A Cross-Sectional Survey.

Author

Ghaseminejad, Farhad, Rich, Kira E., Rosenbaum, Debbie, Rydz, Emilia, Palepu, Anita, Dodek, Peter, Salmon, Amy, Leitch, Heather A., Townson, Andrea, Lacaille, Diane, Varshney, Vishal P., and Khan, Nadia A.

Subjects
MASLACH Burnout Inventory, COVID-19 pandemic, WORK-life balance, URBAN hospitals, PHYSICIANS
Abstract

BACKGROUND: The prevalence of physician burnout increased notably during the COVID-19 pandemic, but whether measures of burnout differed based on physician specialty is unknown. The authors sought to determine the prevalence of burnout, worklife conflict, and intention to quit among physicians from different specialties. METHODS: This is a cross-sectional online survey of physicians working at 2 urban hospitals in Vancouver, Canada, from August to October 2021. Responses were categorized by specialty (including surgical and nonsurgical), and data about whether physicians provided frontline patient care during COVID-19 were also included. Physician burnout was measured using the Maslach Burnout Inventory. RESULTS: The survey response rate was 42% (209/498). The overall prevalence of burnout was 69%. Burnout was not significantly different by specialty or between frontline COVID-19 specialties compared with other specialties. Physicians in surgical specialties were more likely to report work-life conflict than those in nonsurgical specialties (p = 0.012). Differences in intention to quit among specialties were not statistically significant. CONCLUSION: During the COVID-19 pandemic, physician burnout was high across physicians, without significant differences between specialties, highlighting the need to support all physicians. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Revised 15-item MDS-specific frailty scale maintains prognostic potential

Author

Wan, Bo A., Nazha, Aziz, Starkman, Rebecca, Alibhai, Shabbir, Wells, Richard. A., Geddes, Michelle, Zhu, Nancy, Keating, Mary-Margaret, Leber, Brian, Chodirker, Lisa, Sabloff, Mitchell, Christou, Grace, Leitch, Heather A., St-Hilaire, Eve, Finn, Nicholas, Shamy, April, Yee, Karen W. L., Storring, John, Nevill, Thomas J., Delage, Robert, Elemary, Mohamed, Banerji, Versha, Parmentier, Anne, Siddiqui, Mohammad, Kirubananthaan, Aksharh, Mamedov, Alexandre, Zhang, Liying, and Buckstein, Rena

Published
2020
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16. International, evidence-based consensus treatment guidelines for idiopathic multicentric Castleman disease

Author

van Rhee, Frits, Voorhees, Peter, Dispenzieri, Angela, Fosså, Alexander, Srkalovic, Gordan, Ide, Makoto, Munshi, Nikhil, Schey, Stephen, Streetly, Matthew, Pierson, Sheila K., Partridge, Helen L., Mukherjee, Sudipto, Shilling, Dustin, Stone, Katie, Greenway, Amy, Ruth, Jason, Lechowicz, Mary Jo, Chandrakasan, Shanmuganathan, Jayanthan, Raj, Jaffe, Elaine S., Leitch, Heather, Pemmaraju, Naveen, Chadburn, Amy, Lim, Megan S., Elenitoba-Johnson, Kojo S., Krymskaya, Vera, Goodman, Aaron, Hoffmann, Christian, Zinzani, Pier Luigi, Ferrero, Simone, Terriou, Louis, Sato, Yasuharu, Simpson, David, Wong, Raymond, Rossi, Jean-Francois, Nasta, Sunita, Yoshizaki, Kazuyuki, Kurzrock, Razelle, Uldrick, Thomas S., Casper, Corey, Oksenhendler, Eric, and Fajgenbaum, David C.

Published
2018
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22. Phase 1 study of JNJ-64619178, a protein arginine methyltransferase 5 inhibitor, in patients with lower-risk myelodysplastic syndromes

Author

Janssen Research and Development, Haque, Tamanna, López-Cadenas, Félix, Xicoy, Blanca, Alfonso-Pierola, Ana, Platzbecker, Uwe, Avivi, Irit, Brunner, Andrew M., Chromik, Jöerg, Morillo, Daniel, Patel, Manish R., Falantes-González, José Francisco, Leitch, Heather A., Germing, Ulrich, Preis, Meir, Lenox, Laurie, Lauring, Josh, Brown, Regina J., Kalota, Anna, Mehta, Jaydeep, Pastore, Friederike, Gu, Junchen, Mistry, Pankaj, Valcárcel, David, Janssen Research and Development, Haque, Tamanna, López-Cadenas, Félix, Xicoy, Blanca, Alfonso-Pierola, Ana, Platzbecker, Uwe, Avivi, Irit, Brunner, Andrew M., Chromik, Jöerg, Morillo, Daniel, Patel, Manish R., Falantes-González, José Francisco, Leitch, Heather A., Germing, Ulrich, Preis, Meir, Lenox, Laurie, Lauring, Josh, Brown, Regina J., Kalota, Anna, Mehta, Jaydeep, Pastore, Friederike, Gu, Junchen, Mistry, Pankaj, and Valcárcel, David

Abstract

Splicing factor (SF) gene mutations are frequent in myelodysplastic syndromes (MDS), and agents that modulate RNA splicing are hypothesized to provide clinical benefit. JNJ-64619178, a protein arginine methyltransferase 5 (PRMT5) inhibitor, was evaluated in patients with lower-risk (LR) MDS in a multi-part, Phase 1, multicenter study. The objectives were to determine a tolerable dose and to characterize safety, pharmacokinetics, pharmacodynamics, and preliminary clinical activity. JNJ-64619178 was administered on a 14 days on/7 days off schedule or every day on a 21-day cycle to patients with International Prognostic Scoring System (IPSS) Low or Intermediate-1 risk MDS who were red blood cell transfusion-dependent. Twenty-four patients were enrolled; 15 (62.5 %) patients had low IPSS risk score, while 18 (75.0 %) had an SF3B1 mutation. Median duration of treatment was 3.45 months (range: 0.03–6.93). No dose limiting toxicities were observed. The 0.5 mg once daily dose was considered better tolerated and chosen for dose expansion. Twenty-three (95.8 %) patients experienced treatment-emergent adverse events (TEAE). The most common TEAEs were neutropenia (15 [62.5 %]) and thrombocytopenia (14 [58.3 %]). JNJ-64619178 pharmacokinetics was dose-dependent. Target engagement as measured by plasma symmetric di-methylarginine was observed across all dose levels; however, variant allele frequency of clonal mutations in bone marrow or blood did not show sustained reductions from baseline. No patient achieved objective response or hematologic improvement per International Working Group 2006 criteria, or transfusion independence. A tolerable dose of JNJ-64619178 was identified in patients with LR MDS. However, no evidence of clinical benefit was observed.

Published
2023

23. VEXAS syndrome: A review of bone marrow aspirate and biopsies reporting myeloid and erythroid precursor vacuolation

Author

Cherniawsky, Hannah, primary, Friedmann, Jordan, additional, Nicolson, Hamish, additional, Dehghan, Natasha, additional, Stubbins, Ryan J., additional, Foltz, Lynda M., additional, Leitch, Heather A., additional, Sreenivasan, Gayatri M., additional, Ambler, Kimberley L. S., additional, Nevill, Thomas J., additional, McGinnis, Eric, additional, Wilson, Lorena, additional, Beck, David B., additional, Chen, Luke Y. C., additional, and Marcon, Krista M., additional

Published
2023
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24. A predictive model of response to erythropoietin stimulating agents in myelodysplastic syndrome: from the Canadian MDS patient registry

Author

Houston, Brett L., Jayakar, Jennifer, Wells, Richard A., Lenis, Martha, Zhang, Liying, Zhu, Nancy, Leitch, Heather A., Nevill, Thomas J., Yee, Karen W. L., Leber, Brian, Sabloff, Mitchell, St-Hilaire, Eve, Kumar, Rajat, Geddes, Michelle, Shamy, April, Storring, John M., Keating, Mary-Margaret, Elemary, Mohamed, Delage, Robert, Mamedov, Alex, and Buckstein, Rena

Published
2017
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25. The burden of red blood cell transfusions in patients with lower-risk myelodysplastic syndromes and ring sideroblasts: an analysis of the prospective MDS-CAN registry

Author

Buckstein, Rena, primary, Chodirker, Lisa, additional, Yee, Karen W.L., additional, Geddes, Michelle, additional, Leitch, Heather A., additional, Christou, Grace, additional, Banerji, Versha, additional, Leber, Brian, additional, Khalaf, Dina, additional, St-Hilaire, Eve, additional, Finn, Nicholas, additional, Nevill, Thomas, additional, Keating, Mary-Margaret, additional, Storring, John, additional, Parmentier, Anne, additional, Thambipillai, Aksharh, additional, Tang, Derek, additional, Westcott, Christopher, additional, Cameron, Chris, additional, and Spin, Paul, additional

Published
2023
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29. A natural history of lower-risk myelodysplastic syndromes with ring sideroblasts: an analysis of the MDS-CAN registry

Author

Buckstein, Rena, primary, Chodirker, Lisa, additional, Mozessohn, Lee, additional, Yee, Karen W.L, additional, Geddes, Michelle, additional, Zhu, Nancy, additional, Shamy, April, additional, Leitch, Heather A., additional, Christou, Grace, additional, Banerji, Versha, additional, Brian, Leber, additional, Khalaf, Dina, additional, St-Hilaire, Eve, additional, Finn, Nicholas, additional, Nevill, Thomas, additional, Keating, Mary-Margaret, additional, Storring, John, additional, Delage, Robert, additional, Parmentier, Anne, additional, Thambipillai, Aksharh, additional, Siddiqui, Mohammed, additional, Westcott, Christopher, additional, Cameron, Chris, additional, Mamedov, Alexandre, additional, Spin, Paul, additional, and Tang, Derek, additional

Published
2022
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30. High transferrin saturation predicts inferior clinical outcomes in patients with myelodysplastic syndromes

Author

Teichman, Jennifer, primary, Geddes, Michelle, additional, Zhu, Nancy, additional, Keating, Mary-Margaret, additional, Sabloff, Mitchell, additional, Christou, Grace, additional, Leber, Brian, additional, Khalaf, Dina, additional, St-Hilaire, Eve, additional, Finn, Nicholas, additional, Shamy, April, additional, Yee, Karen W.L., additional, Storring, John M., additional, Nevill, Thomas J., additional, Delage, Robert, additional, Elemary, Mohamed, additional, Banerji, Versha, additional, Houston, Brett, additional, Mozessohn, Lee, additional, Chodirker, Lisa, additional, Zhang, Liying, additional, Siddiqui, Mohammed, additional, Parmentier, Anne, additional, Leitch, Heather A., additional, and Buckstein, Rena J., additional

Published
2022
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33. Overall survival in lower IPSS risk MDS by receipt of iron chelation therapy, adjusting for patient‐related factors and measuring from time of first red blood cell transfusion dependence: an MDS‐CAN analysis

Author

Leitch, Heather A., Parmar, Ambica, Wells, Richard A., Chodirker, Lisa, Zhu, Nancy, Nevill, Thomas J., Yee, Karen W. L., Leber, Brian, Keating, Mary‐Margaret, Sabloff, Mitchell, St. Hilaire, Eve, Kumar, Rajat, Delage, Robert, Geddes, Michelle, Storring, John M., Kew, Andrea, Shamy, April, Elemary, Mohamed, Lenis, Martha, Mamedov, Alexandre, Ivo, Jessica, Francis, Janika, Zhang, Liying, and Buckstein, Rena

Published
2017
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34. ITACA: A new validated international erythropoietic stimulating agent‐response score that further refines the predictive power of previous scoring systems

Author

Buckstein, Rena, Balleari, Enrico, Wells, Richard, Santini, Valeria, Sanna, Alessandro, Salvetti, Chiara, Crisà, Elena, Allione, Bernardino, Danise, Paolo, Finelli, Carlo, Clavio, Marino, Poloni, Antonella, Salvi, Flavia, Cilloni, Daniela, Oliva, Esther Natalie, Musto, Pellegrino, Houston, Brett, Zhu, Nancy, Geddes, Michelle, Leitch, Heather, Leber, Brian, Sabloff, Mitchell, Nevill, Thomas J., Yee, Karen W., Storring, John M., Francis, Janika, Maurillo, Luca, Latagliata, Roberto, Spiriti, Maria Antonietta Aloe, Andriani, Alessandro, Piccioni, Anna Lina, Fianchi, Luana, Fenu, Susanna, Gumenyuk, Svitlana, and Buccisano, Francesco

Published
2017
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43. Phase 1 Study of JNJ-64619178, a Protein Arginine Methyltransferase 5 Inhibitor, in Patients with Lower-Risk Myelodysplastic Syndromes

Author

Haque, Tamanna, primary, Cadenas, Felix López, additional, Xicoy, Blanca, additional, Alfonso, Ana, additional, Platzbecker, Uwe, additional, Avivi, Irit, additional, Brunner, Andrew M., additional, Chromik, Jörg, additional, Morillo, Daniel, additional, Patel, Manish R., additional, Falantes, José F., additional, Leitch, Heather A., additional, Germing, Ulrich, additional, Preis, Meir, additional, Lavie, David, additional, Lenox, Laurie, additional, Lauring, Josh, additional, Kalota, Anna, additional, Brown, Regina, additional, Mehta, Jaydeep, additional, Pastore, Friederike, additional, Mistry, Pankaj, additional, and Valcarcel, David, additional

Published
2021
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48. Fatigue, However Measured, Continues to Refine Prognosis in Higher Risk MDS: An MDS-CAN Study

Author

Amitai, Irina, Geddes, Michelle, Zhu, Nancy, Keating, Mary-Margaret, Sabloff, Mitchell, Christou, Grace, Leber, Brian, Khalaf, Dina, Leitch, Heather A., St-Hilaire, Eve, Finn, Nicholas, Shamy, April, Yee, Karen W.L., Storring, John M., Nevill, Thomas J., Delage, Robert, Elemary, Mohamed, Banerji, Versha, Chodirker, Lisa, Mozessohn, Lee, Parmentier, Anne, Siddiqui, Mohammed, Mamedov, Alexandre, Zhang, Liying, and Buckstein, Rena J.

Published
2020
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49. Patient‐reported fatigue refines prognosis in higher‐risk myelodysplastic syndromes (MDS): a MDS‐CAN study

Author

Amitai, Irina, primary, Geddes, Michelle, additional, Zhu, Nancy, additional, Keating, Mary‐Margaret, additional, Sabloff, Mitchell, additional, Christou, Grace, additional, Leber, Brian, additional, Khalaf, Dina, additional, Leitch, Heather A., additional, St‐Hilaire, Eve, additional, Finn, Nicholas, additional, Shamy, April, additional, Yee, Karen, additional, Storring, John, additional, Nevill, Thomas, additional, Delage, Robert, additional, Elemary, Mohamed, additional, Banerji, Versha, additional, Chodirker, Lisa, additional, Mozessohn, Lee, additional, Parmentier, Anne, additional, Siddiqui, Mohammed, additional, Mamedov, Alexandre, additional, Zhang, Liying, additional, and Buckstein, Rena, additional

Published
2021
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