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Walters G, Wei M, Voznyy O, Quintero-Bermudez R, Kiani A, Smilgies DM, Munir R, Amassian A, Hoogland S, Sargent E. The quantum-confined Stark effect in layered hybrid perovskites mediated by orientational polarizability of confined dipoles. Nat Commun 2018; 9:4214. [PMID: 30310072 PMCID: PMC6181967 DOI: 10.1038/s41467-018-06746-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 09/25/2018] [Indexed: 11/19/2022] Open
Abstract
The quantum-confined Stark effect (QCSE) is an established optical modulation mechanism, yet top-performing modulators harnessing it rely on costly fabrication processes. Here, we present large modulation amplitudes for solution-processed layered hybrid perovskites and a modulation mechanism related to the orientational polarizability of dipolar cations confined within these self-assembled quantum wells. We report an anomalous (blue-shifting) QCSE for layers that contain methylammonium cations, in contrast with cesium-containing layers that show normal (red-shifting) behavior. We attribute the blue-shifts to an extraordinary diminution in the exciton binding energy that arises from an augmented separation of the electron and hole wavefunctions caused by the orientational response of the dipolar cations. The absorption coefficient changes, realized by either the red- or blue-shifts, are the strongest among solution-processed materials at room temperature and are comparable to those exhibited in the highest-performing epitaxial compound semiconductor heterostructures.
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Affiliation(s)
- G Walters
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON, M5S 1A4, Canada
| | - M Wei
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON, M5S 1A4, Canada
| | - O Voznyy
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON, M5S 1A4, Canada
| | - R Quintero-Bermudez
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON, M5S 1A4, Canada
| | - A Kiani
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON, M5S 1A4, Canada
| | - D-M Smilgies
- CHESS Wilson Laboratory, Cornell University, 161 Synchrotron Drive, Ithaca, NY, 14853, USA
| | - R Munir
- Physical and Engineering Sciences Division, KAUST Solar Center (KSU), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - A Amassian
- Physical and Engineering Sciences Division, KAUST Solar Center (KSU), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - S Hoogland
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON, M5S 1A4, Canada
| | - E Sargent
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON, M5S 1A4, Canada.
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Loberg RD, Ying C, Craig M, Day LL, Sargent E, Neeley C, Wojno K, Snyder LA, Yan L, Pienta KJ. Targeting CCL2 with systemic delivery of neutralizing antibodies induces prostate cancer tumor regression in vivo. Cancer Res 2007; 67:9417-24. [PMID: 17909051 DOI: 10.1158/0008-5472.can-07-1286] [Citation(s) in RCA: 259] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The identification of novel tumor-interactive chemokines and the associated insights into the molecular and cellular basis of tumor-microenvironment interactions have continued to stimulate the development of targeted cancer therapeutics. Recently, we have identified monocyte chemoattractant protein 1 (MCP-1; CCL2) as a prominent regulator of prostate cancer growth and metastasis. Using neutralizing antibodies to human CCL2 (CNTO888) and the mouse homologue CCL2/JE (C1142), we show that treatment with anti-CCL2/JE antibody (2 mg/kg, twice weekly i.p.) attenuated PC-3Luc-mediated overall tumor burden in our in vivo model of prostate cancer metastasis by 96% at 5 weeks postintracardiac injection. Anti-CCL2 inhibition was not as effective as docetaxel (40 mg/kg, every week for 3 weeks) as a single agent, but inhibition of CCL2 in combination with docetaxel significantly reduced overall tumor burden compared with docetaxel alone, and induced tumor regression relative to initial tumor burden. These data suggest an interaction between tumor-derived chemokines and host-derived chemokines acting in cooperation to promote tumor cell survival, proliferation, and metastasis.
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Affiliation(s)
- Robert D Loberg
- Department of Urology, University of Michigan Urology Center, Ann Arbor, Michigan 48109-0946, USA.
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Abstract
24 community midwives recorded details of 783 postnatal visits over a 2 week period. The findings provide a description of postnatal visiting practice in Lothian Region, Scotland. Analysis revealed that 10 factors were significantly associated with the duration of visits. These could be grouped as follows: time consuming procedures (physical examination of the mother or baby, PKU testing), administration-related (the number of other visits that day, the need to liaise with general practitioners or health visitors, whether the mother was already known to the midwife, the time kept waiting at the house), feeding-related (the existence of feeding problems, whether the mother had breast fed previously) and delivery-related (the existence of complications during the delivery). The presence of health, social or emotional problems, or the lack of family/partner support was not associated with longer visits. The implications of these findings are discussed.
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Sargent E. Infirmaries: a way to reduce medical costs? West J Med 1981; 134:364. [PMID: 18748859 PMCID: PMC1272707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- E Sargent
- Student Health Center, Oregon State University, Corvallis, Oregon
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Sargent E. Possible hazards of nylon athletic shorts. West J Med 1981; 134:168. [PMID: 18748800 PMCID: PMC1272554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- E Sargent
- Student Health Center, Oregon State University, Corvallis, OR
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Sargent E. Irish spring soap. West J Med 1979; 131:448. [PMID: 18748519 PMCID: PMC1271889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- E Sargent
- Student Health Center, Oregon State University, Corvallis, Oregon
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Sargent E. The cost of continuing medical education. West J Med 1978; 129:347. [PMID: 18748308 PMCID: PMC1238368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- E Sargent
- Student Health Center, Oregon State University, Corvallis, Oregon
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Abstract
Three children had osteomyelitis due to Haemophilus influenzae type b. They were seen with signs and symptoms indistinguishable from infection caused by other organisms. One child was initially misdiagnosed as having septic arthritis because of failure to appreciate that Hemophilus may also cause bone infection. In the second patient osteomyelitis and arthritis developed during ampicillin sodium therapy for treatment of Hemophilus meningitis. His initial infection was caused by an ampicillin-sensitive isolate but his orthopedic infection subsequently responded to therapy only after changing to a regimen of chloramphenicol. In the third patient, bone scintigraphy was helpful in diagnosis since serial roentgenograms were not diagnostic of osteomyelitis. The anticapsular antibody responses of these patients were measured by radioimmune assay. The levels found were low but comparable to age-matched control children with H influenzae type b meningitis.
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