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Rank L, Dogan O, Kopp B, Mein S, Verona-Rinati G, Kranzer R, Marinelli M, Mairani A, Tessonnier T. Development and benchmarking of a dose rate engine for raster-scanned FLASH helium ions. Med Phys 2024; 51:2251-2262. [PMID: 37847027 PMCID: PMC10939952 DOI: 10.1002/mp.16793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 09/14/2023] [Accepted: 10/06/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Radiotherapy with charged particles at high dose and ultra-high dose rate (uHDR) is a promising technique to further increase the therapeutic index of patient treatments. Dose rate is a key quantity to predict the so-called FLASH effect at uHDR settings. However, recent works introduced varying calculation models to report dose rate, which is susceptible to the delivery method, scanning path (in active beam delivery) and beam intensity. PURPOSE This work introduces an analytical dose rate calculation engine for raster scanned charged particle beams that is able to predict dose rate from the irradiation plan and recorded beam intensity. The importance of standardized dose rate calculation methods is explored here. METHODS Dose is obtained with an analytical pencil beam algorithm, using pre-calculated databases for integrated depth dose distributions and lateral penumbra. Dose rate is then calculated by combining dose information with the respective particle fluence (i.e., time information) using three dose-rate-calculation models (mean, instantaneous, and threshold-based). Dose rate predictions for all three models are compared to uHDR helium ion beam (145.7 MeV/u, range in water of approximatively 14.6 cm) measurements performed at the Heidelberg Ion Beam Therapy Center (HIT) with a diamond-detector prototype. Three scanning patterns (scanned or snake-like) and four field sizes are used to investigate the dose rate differences. RESULTS Dose rate measurements were in good agreement with in-silico generated distributions using the here introduced engine. Relative differences in dose rate were below 10% for varying depths in water, from 2.3 to 14.8 cm, as well as laterally in a near Bragg peak area. In the entrance channel of the helium ion beam, dose rates were predicted within 7% on average for varying irradiated field sizes and scanning patterns. Large differences in absolute dose rate values were observed for varying calculation methods. For raster-scanned irradiations, the deviation between mean and threshold-based dose rate at the investigated point was found to increase with the field size up to 63% for a 10 mm × 10 mm field, while no significant differences were observed for snake-like scanning paths. CONCLUSIONS This work introduces the first dose rate calculation engine benchmarked to instantaneous dose rate, enabling dose rate predictions for physical and biophysical experiments. Dose rate is greatly affected by varying particle fluence, scanning path, and calculation method, highlighting the need for a consensus among the FLASH community on how to calculate and report dose rate in the future. The here introduced engine could help provide the necessary details for the analysis of the sparing effect and uHDR conditions.
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Affiliation(s)
- Luisa Rank
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Karlsruhe Institute of Technology (KIT), Faculty of Physics, Karlsruhe, Germany
| | - Ozan Dogan
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Heidelberg University, Faculty of Physics and Astronomy, Heidelberg, Germany
| | - Benedikt Kopp
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Stewart Mein
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Department of Radiation Oncology, Heidelberg University Hospital (UKHD), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital (UKHD), Heidelberg Faculty of Medicine (MFHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Rafael Kranzer
- PTW-Freiburg, Freiburg, Germany
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University Oldenburg, Germany
| | - Marco Marinelli
- Industrial Engineering Department, University of Rome “Tor Vergata”, Rome, Italy
| | - Andrea Mairani
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Department of Radiation Oncology, Heidelberg University Hospital (UKHD), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital (UKHD), Heidelberg Faculty of Medicine (MFHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Physics, National Centre of Oncological Hadrontherapy (CNAO), Pavia, Italy
| | - Thomas Tessonnier
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital (UKHD), Heidelberg Faculty of Medicine (MFHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
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Cetnar AJ, Jain S, Gupta N, Chakravarti A. Technical note: Commissioning of a linear accelerator producing ultra-high dose rate electrons. Med Phys 2024; 51:1415-1420. [PMID: 38159300 DOI: 10.1002/mp.16925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 12/12/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND Ultra-high dose rate radiation (UHDR) is being explored by researchers in promise of advancing radiation therapy treatments. PURPOSE This work presents the commissioning of Varian's Flash Extension for research (FLEX) conversion of a Clinac to deliver UHDR electrons. METHODS A Varian Clinac iX with the FLEX conversion was commissioned for non-clinical research use with 16 MeV UHDR (16H) energy. This involved addition of new hardware, optimizing the electron gun voltages, radiofrequency (RF) power, and steering coils in order to maximize the accelerated electron beam current, sending the beam through custom scattering foils to produce the UHDR with 16H beam. Profiles and percent depth dose (PDD) measurements for 16H were obtained using radiochromic film in a custom vertical film holder and were compared to 16 MeV conventional electrons (16C). Dose rate and dose per pulse (DPP) were calculated from measured dose in film. Linearity and stability were assessed using an Advanced Markus ionization chamber. RESULTS Energies for 16H and 16C had similar beam quality based on PDD measurements. Measurements at the head of the machine (61.3 cm SSD) with jaws set to 10×10 cm2 showed the FWHM of the profile as 7.2 cm, with 3.4 Gy as the maximum DPP and instantaneous dose rate of 8.1E5 Gy/s. Measurements at 100 cm SSD with 10 cm standard cone showed the full width at half max (FWHM) of the profile as 10.5 cm, 1.08 Gy as the maximum DPP and instantaneous dose rate of 2.E5 Gy/s. Machine output with number of pulses was linear (R = 1) from 1 to 99 delivered pulses. Output stability was measured within ±1% within the same session and within ±2% for daily variations. CONCLUSIONS The FLEX conversion of the Clinac is able to generate UHDR electron beams which are reproducible with beam properties similar to clinically used electrons at 16 MeV. Having a platform which can quickly transition between UHDR and conventional modes (<1 min) can be advantageous for future research applications.
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Affiliation(s)
- Ashley J Cetnar
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Sagarika Jain
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Nilendu Gupta
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Arnab Chakravarti
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
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Fernández-Parrado M, Rodríguez-Cuadrado FJ, Pinto-Pulido EL, Perandones-González H. Upside down camera for oral cavity photography. J Am Acad Dermatol 2023; 89:e271-e272. [PMID: 36623555 DOI: 10.1016/j.jaad.2022.12.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/05/2022] [Accepted: 12/20/2022] [Indexed: 01/09/2023]
Affiliation(s)
| | | | - Elena Lucía Pinto-Pulido
- Department of Dermatology, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Spain
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Polevoy GG, Kumar DS, Daripelli S, Prasanna M. Flash Therapy for Cancer: A Potentially New Radiotherapy Methodology. Cureus 2023; 15:e46928. [PMID: 38021805 PMCID: PMC10640654 DOI: 10.7759/cureus.46928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2023] [Indexed: 12/01/2023] Open
Abstract
In traditional treatment modalities and standard clinical practices, FLASH radiotherapy (FL-RT) administers radiation therapy at an exceptionally high dosage rate. When compared to standard dose rate radiation therapy, numerous preclinical investigations have demonstrated that FL-RT provides similar benefits in conserving normal tissue while maintaining equal antitumor efficacy, a phenomenon possible due to the 'FLASH effect' (FE) of FL-RT. The methodologies involve proton radiotherapy, intensity-modulated radiation treatment, and managing high-throughput damage by radiation to solid tissues. Recent results from animal studies indicate that FL-RT can reduce radiation-induced tissue damage, significantly enhancing anticancer potency. Focusing on the potential benefits of FL proton beam treatment in the years to come, this review details the FL-RT research that has been done so far and the existing theories illuminating the FL effects. This subject remains of interest, with many issues still needing to be answered. We offer a brief review to emphasize a few of the key efforts and difficulties in moving FL radiation research forward. The existing research state of FL-RT, its affecting variables, and its different specific impacts are presented in this current review. Key topics discussed include the biochemical mechanism during FL therapy, beam sources for FL therapy, the FL effect on immunity, clinical and preclinical studies on the protective effect of FL therapy, and parameters for effective FL therapy.
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Affiliation(s)
| | - Devika S Kumar
- Department of Research and Development, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, IND
| | - Sushma Daripelli
- Department of Anatomy, Government Medical College (GMC) Jangaon, Jangaon, IND
| | - Muthu Prasanna
- Department of Pharmaceutical Biotechnology, Surya Group of Institutions, Tamil Nadu, IND
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Zou W, Zhang R, Schüler E, Taylor PA, Mascia AE, Diffenderfer ES, Zhao T, Ayan AS, Sharma M, Yu SJ, Lu W, Bosch WR, Tsien C, Surucu M, Pollard-Larkin JM, Schuemann J, Moros EG, Bazalova-Carter M, Gladstone DJ, Li H, Simone CB, Petersson K, Kry SF, Maity A, Loo BW, Dong L, Maxim PG, Xiao Y, Buchsbaum JC. Framework for Quality Assurance of Ultrahigh Dose Rate Clinical Trials Investigating FLASH Effects and Current Technology Gaps. Int J Radiat Oncol Biol Phys 2023; 116:1202-1217. [PMID: 37121362 PMCID: PMC10526970 DOI: 10.1016/j.ijrobp.2023.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/28/2023] [Accepted: 04/17/2023] [Indexed: 05/02/2023]
Abstract
FLASH radiation therapy (FLASH-RT), delivered with ultrahigh dose rate (UHDR), may allow patients to be treated with less normal tissue toxicity for a given tumor dose compared with currently used conventional dose rate. Clinical trials are being carried out and are needed to test whether this improved therapeutic ratio can be achieved clinically. During the clinical trials, quality assurance and credentialing of equipment and participating sites, particularly pertaining to UHDR-specific aspects, will be crucial for the validity of the outcomes of such trials. This report represents an initial framework proposed by the NRG Oncology Center for Innovation in Radiation Oncology FLASH working group on quality assurance of potential UHDR clinical trials and reviews current technology gaps to overcome. An important but separate consideration is the appropriate design of trials to most effectively answer clinical and scientific questions about FLASH. This paper begins with an overview of UHDR RT delivery methods. UHDR beam delivery parameters are then covered, with a focus on electron and proton modalities. The definition and control of safe UHDR beam delivery and current and needed dosimetry technologies are reviewed and discussed. System and site credentialing for large, multi-institution trials are reviewed. Quality assurance is then discussed, and new requirements are presented for treatment system standard analysis, patient positioning, and treatment planning. The tables and figures in this paper are meant to serve as reference points as we move toward FLASH-RT clinical trial performance. Some major questions regarding FLASH-RT are discussed, and next steps in this field are proposed. FLASH-RT has potential but is associated with significant risks and complexities. We need to redefine optimization to focus not only on the dose but also on the dose rate in a manner that is robust and understandable and that can be prescribed, validated, and confirmed in real time. Robust patient safety systems and access to treatment data will be critical as FLASH-RT moves into the clinical trials.
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Affiliation(s)
- Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Rongxiao Zhang
- Department of Radiation Oncology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Emil Schüler
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Paige A Taylor
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Eric S Diffenderfer
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Tianyu Zhao
- Department of Radiation Oncology, Washington University, St. Louis, MO, USA
| | - Ahmet S Ayan
- Department of Radiation Oncology, Ohio State University, Columbus, OH, USA
| | - Manju Sharma
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
| | - Shu-Jung Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Weiguo Lu
- Department of Radiation Oncology, University of Texas Southwestern, Dallas, TX, USA
| | - Walter R Bosch
- Department of Radiation Oncology, Washington University, St. Louis, MO, USA
| | - Christina Tsien
- Department of Radiation Oncology, McGill University Health Center, Montreal, QC, Canada
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Julianne M Pollard-Larkin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Eduardo G Moros
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | | | - David J Gladstone
- Department of Radiation Oncology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Heng Li
- Department of Radiation Oncology, Johns Hopkins University, Baltimore, MD, USA
| | - Charles B Simone
- Department of Radiation Oncology, New York Proton Center, New York, NY, USA
| | - Kristoffer Petersson
- Department of Radiation Oncology, MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Amit Maity
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Peter G Maxim
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA
| | - Ying Xiao
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeffrey C Buchsbaum
- Radiation Research Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institute of Health, Bethesda, MD, USA
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Joyce DS, Spitschan M, Zeitzer JM. Optimizing Light Flash Sequence Duration to Shift Human Circadian Phase. Biology (Basel) 2022; 11. [PMID: 36552316 DOI: 10.3390/biology11121807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022]
Abstract
Unlike light input for forming images, non-image-forming retinal pathways are optimized to convey information about the total light environment, integrating this information over time and space. In a variety of species, discontinuous light sequences (flashes) can be effective stimuli, notably impacting circadian entrainment. In this study, we examined the extent to which this temporal integration can occur. A group of healthy, young (n = 20) individuals took part in a series of 16-day protocols in which we examined the impact of different lengths of light flash sequences on circadian timing. We find a significant phase change of -0.70 h in response to flashes that did not differ by duration; a 15-min sequence could engender as much change in circadian timing as 3.5-h sequences. Acute suppression of melatonin was also observed during short (15-min) exposures, but not in exposures over one hour in length. Our data are consistent with the theory that responses to light flashes are mediated by the extrinsic, rod/cone pathway, and saturate the response of this pathway within 15 min. Further excitation leads to no greater change in circadian timing and an inability to acutely suppress melatonin, indicating that this pathway may be in a refractory state following this brief light stimulation.
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Lv Y, Lv Y, Wang Z, Lan T, Feng X, Chen H, Zhu J, Ma X, Du J, Hou G, Liao W, Yuan K, Wu H. FLASH radiotherapy: A promising new method for radiotherapy. Oncol Lett 2022; 24:419. [PMID: 36284652 PMCID: PMC9580247 DOI: 10.3892/ol.2022.13539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/10/2022] [Indexed: 11/06/2022] Open
Abstract
Among the treatments for malignant tumors, radiotherapy is of great significance both as a main treatment and as an adjuvant treatment. Radiation therapy damages cancer cells with ionizing radiation, leading to their death. However, radiation-induced toxicity limits the dose delivered to the tumor, thereby constraining the control effect of radiotherapy on tumor growth. In addition, the delayed toxicity caused by radiotherapy significantly harms the physical and mental health of patients. FLASH-RT, an emerging class of radiotherapy, causes a phenomenon known as the 'FLASH effect', which delivers radiotherapy at an ultra-high dose rate with lower toxicity to normal tissue than conventional radiotherapy to achieve local tumor control. Although its mechanism remains to be fully elucidated, this modality constitutes a potential new approach to treating malignant tumors. In the present review, the current research progress of FLASH-RT and its various particular effects are described, including the status of research on FLASH-RT and its influencing factors. The hypothetic mechanism of action of FLASH-RT is also summarized, providing insight into future tumor treatments.
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Affiliation(s)
- Yinghao Lv
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Yue Lv
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Zhen Wang
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Tian Lan
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Xuping Feng
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Hao Chen
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Jiang Zhu
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Xiao Ma
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Jinpeng Du
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Guimin Hou
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Wenwei Liao
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Kefei Yuan
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Hong Wu
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
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Vu BV, Lei R, Mohan C, Kourentzi K, Willson RC. Flash Characterization of Smartphones Used in Point-of-Care Diagnostics. Biosensors (Basel) 2022; 12:1060. [PMID: 36551027 PMCID: PMC9776052 DOI: 10.3390/bios12121060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/03/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
Rapidly growing interest in smartphone cameras as the basis of point-of-need diagnostic and bioanalytical technologies increases the importance of quantitative characterization of phone optical performance under real-world operating conditions. In the context of our development of lateral-flow immunoassays based on phosphorescent nanoparticles, we have developed a suite of tools for characterizing the temporal and spectral profiles of smartphone torch and flash emissions, and their dependence on phone power state. In this work, these tools are described and documented to make them easily available to others, and demonstrated by application to characterization of Apple iPhone 5s, iPhone 6s, iPhone 8, iPhone XR, and Samsung Note8 flash performance as a function of time and wavelength, at a variety of power settings. Flash and torch intensity and duration vary with phone state and among phone models. Flash has high variability when the battery charge is below 10%, thus, smartphone-based Point-of-Care (POC) tests should only be performed at a battery level of at least 15%. Some output variations could substantially affect the results of assays that rely on the smartphone flash.
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Affiliation(s)
- Binh V. Vu
- William A. Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204, USA
| | - Rongwei Lei
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA
| | - Chandra Mohan
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA
| | - Katerina Kourentzi
- William A. Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204, USA
| | - Richard C. Willson
- William A. Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204, USA
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA
- Escuela de Medicina y Ciencias de la Salud ITESM, Monterrey 64710, NL, Mexico
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Joyce DS, Spitschan M, Zeitzer JM. Duration invariance and intensity dependence of the human circadian system phase shifting response to brief light flashes. Proc Biol Sci 2022; 289:20211943. [PMID: 35259981 PMCID: PMC8905166 DOI: 10.1098/rspb.2021.1943] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 02/14/2022] [Indexed: 01/09/2023] Open
Abstract
The melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are characterized by a delayed off-time following the cessation of light stimulation. Here, we exploited this unusual physiologic property to characterize the exquisite sensitivity of the human circadian system to flashed light. In a 34 h in-laboratory between-subjects design, we examined phase shifting in response to variable-intensity (3-9500 photopic lux) flashes at fixed duration (2 ms; n = 28 participants) and variable-duration (10 µs-10 s) flashes at fixed intensity (2000 photopic lux; n = 31 participants). Acute melatonin suppression, objective alertness and subjective sleepiness during the flash sequence were also assessed. We find a dose-response relationship between flash intensity and circadian phase shift, with an indication of a possible threshold-like behaviour. We find a slight parametric relationship between flash duration and circadian phase shift. Consistent with prior studies, we observe no dose-response relationship to either flash intensity or duration and the acute impact of light on melatonin suppression, objective alertness or subjective sleepiness. Our findings are consistent with circadian responses to a sequence of flashes being mediated by rod or cone photoreceptors via ipRGC integration.
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Affiliation(s)
- Daniel S. Joyce
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Mental Illness Research Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA, USA
- Department of Psychology, University of Nevada Reno, Reno, NV, USA
| | - Manuel Spitschan
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Translational Sensory and Circadian Neuroscience, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- TUM Department of Sport and Health Sciences (TUM SG), Technical University of Munich, Munich, Germany
| | - Jamie M. Zeitzer
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Mental Illness Research Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA, USA
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10
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Schwarz M, Traneus E, Safai S, Kolano A, van de Water S. Treatment planning for Flash radiotherapy: general aspects and applications to proton beams. Med Phys 2022; 49:2861-2874. [PMID: 35213040 DOI: 10.1002/mp.15579] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 12/22/2021] [Accepted: 02/14/2022] [Indexed: 11/08/2022] Open
Abstract
The increased radioresistence of healthy tissues when irradiated at very high dose rates (known as the Flash effect) is a radiobiological mechanism that is currently investigated in order to increase the therapeutic ratio of radiotherapy treatments. To maximize the benefits of the clinical application of Flash, a patient-specific balance between different properties of the dose distribution should be found, i.e. Flash needs to be one of the variables considered in treatment planning. We investigated the Flash potential of three proton therapy planning and beam delivery techniques, each on a different anatomical region. Based on a set of beam delivery parameters, on hypotheses on the dose and dose rate thresholds needed for the Flash effect to occur, and on two definitions of Flash dose rate, we generated exemplary illustrations of the capabilities of current proton therapy equipment to generate Flash dose distributions. All techniques investigated could both produce dose distributions comparable with a conventional proton plan and reach the Flash regime, to an extent that was strongly dependent on the dose per fraction and the Flash dose threshold. The beam current, Flash dose rate threshold and dose rate definition typically had a more moderate effect on the amount of Flash dose in normal tissue. A systematic estimation of the impact of Flash on different patient anatomies and treatment protocols is possible only if Flash-specific treatment planning features become readily available. Planning evaluation tools such as a voxel-based dose delivery time structure, and the inclusion in the optimization cost function of parameters directly associated with Flash (e.g. beam current, spot delivery sequence and scanning speed), are needed to generate treatment plans that are taking full advantage of the potential benefits of the Flash effect. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Marco Schwarz
- Proton therapy Department, Trento Hospital and TIFPA-INFN, Trento, Italy
| | - Erik Traneus
- RaySearch Laboratories AB, Stockholm SE-103 65, Sweden
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Anna Kolano
- Advanced Oncotherapy plc, London, England - Application of Detectors and Accelerators to Medicine(ADAM), Geneva, Switzerland
| | - Steven van de Water
- Department of Radiation Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Amsterdam, The Netherlands
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11
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Zhang C, Li Y, Li Z, Jiang Y, Zhang J, Zhao R, Zou J, Wang Y, Wang K, Ma C, Zhang Q. Nanofiber Architecture Engineering Implemented by Electrophoretic-Induced Self-Assembly Deposition Technology for Flash-Type Memristors. ACS Appl Mater Interfaces 2022; 14:3111-3120. [PMID: 34985856 DOI: 10.1021/acsami.1c22094] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Electrophoretic deposition (EPD) has been recognized as a promising large-scale film preparation technology for industrial application. Inspired by the conventional EPD method and the crystal diffusion growth strategy, we propose a modified electrophoretic-induced self-assembly deposition (EPAD) technique to control the morphologies of organic functional materials. Here, an ionic-type dye with a conjugated skeleton and strong noncovalent interactions, celestine blue (CB), is chosen as a module molecule for EPAD investigation. As expected, CB molecules can assemble into different nanostructures, dominated by applied voltage, concentration effect, and duration. Compared to a nanopillar layered packing structure formed by the traditional spin-coating method, the EPAD approach can produce a nanofiber structure under a fixed condition of 10 V/10 min. Intriguingly, a memristor device based on a pillar-like nanostructure exhibits WORM-type behavior, while a device based on nanofibers presents Flash memory performance. The assemble process and the memory mechanism are uncovered by molecular dynamics simulations and density-functional theory (DFT) calculations. This work endows the typical EPD technique with a fresh application scenario, where an in-depth study on the growth mechanism of nanofibers and the positive effect of unique morphologies on memristor performance are offered.
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Affiliation(s)
- Cheng Zhang
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China
| | - Yang Li
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China
| | - Zhuang Li
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Yucheng Jiang
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China
| | - Jinlei Zhang
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China
| | - Run Zhao
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China
| | - Jingyun Zou
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China
| | - Yanan Wang
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Kuaibing Wang
- Jiangsu Key Laboratory of Pesticide Sciences, Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunlan Ma
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China
| | - Qichun Zhang
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China
- Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China
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12
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Wright MD, Romanelli P, Bravin A, Le Duc G, Brauer-Krisch E, Requardt H, Bartzsch S, Hlushchuk R, Laissue JA, Djonov V. Non-conventional Ultra-High Dose Rate ( FLASH) Microbeam Radiotherapy Provides Superior Normal Tissue Sparing in Rat Lung Compared to Non-conventional Ultra-High Dose Rate (FLASH) Radiotherapy. Cureus 2021; 13:e19317. [PMID: 35223216 PMCID: PMC8864723 DOI: 10.7759/cureus.19317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2021] [Indexed: 12/12/2022] Open
Abstract
Conventional radiotherapy is a widely used non-invasive form of treatment for many types of cancer. However, due to a low threshold in the lung for radiation-induced normal tissue damage, it is of less utility in treating lung cancer. For this reason, surgery is the preferred treatment for lung cancer, which has the detriment of being highly invasive. Non-conventional ultra-high dose rate (FLASH) radiotherapy is currently of great interest in the radiotherapy community due to demonstrations of reduced normal tissue toxicity in lung and other anatomy. This study investigates the effects of FLASH microbeam radiotherapy, which in addition to ultra-high dose rate incorporates a spatial segmentation of the radiation field, on the normal lung tissue of rats. With a focus on fibrotic damage, this work demonstrates that FLASH microbeam radiotherapy provides an order of magnitude increase in normal tissue radio-resistance compared to FLASH radiotherapy. This result suggests FLASH microbeam radiotherapy holds promise for much improved non-invasive control of lung cancer.
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Affiliation(s)
- Michael D Wright
- Ginzton Technology Center, Varian Medical Systems, Palo Alto, USA.,Research & Development Center, Avail Medical Devices, Roseville, USA
| | | | - Alberto Bravin
- Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble, FRA
| | - Geraldine Le Duc
- Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble, FRA.,Pharmaceutics, NH TherAguix, Lyon, FRA
| | - Elke Brauer-Krisch
- Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble, FRA
| | - Herwig Requardt
- Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble, FRA
| | - Stefan Bartzsch
- Department of Radiation Oncology, School of Medicine, Technical University of Munich, Munich, DEU.,Institute for Radiation Medicine, Helmholtz Centre Munich, Munich, DEU
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13
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Konradsson E, Arendt ML, Bastholm Jensen K, Børresen B, Hansen AE, Bäck S, Kristensen AT, Munck Af Rosenschöld P, Ceberg C, Petersson K. Establishment and Initial Experience of Clinical FLASH Radiotherapy in Canine Cancer Patients. Front Oncol 2021; 11:658004. [PMID: 34055624 PMCID: PMC8155542 DOI: 10.3389/fonc.2021.658004] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/26/2021] [Indexed: 01/19/2023] Open
Abstract
FLASH radiotherapy has emerged as a treatment technique with great potential to increase the differential effect between normal tissue toxicity and tumor response compared to conventional radiotherapy. To evaluate the feasibility of FLASH radiotherapy in a relevant clinical setting, we have commenced a feasibility and safety study of FLASH radiotherapy in canine cancer patients with spontaneous superficial solid tumors or microscopic residual disease, using the electron beam of our modified clinical linear accelerator. The setup for FLASH radiotherapy was established using a short electron applicator with a nominal source-to-surface distance of 70 cm and custom-made Cerrobend blocks for collimation. The beam was characterized by measuring dose profiles and depth dose curves for various field sizes. Ten canine cancer patients were included in this initial study; seven patients with nine solid superficial tumors and three patients with microscopic disease. The administered dose ranged from 15 to 35 Gy. To ensure correct delivery of the prescribed dose, film measurements were performed prior to and during treatment, and a Farmer-type ion-chamber was used for monitoring. Treatments were found to be feasible, with partial response, complete response or stable disease recorded in 11/13 irradiated tumors. Adverse events observed at follow-up ranging from 3-6 months were mild and consisted of local alopecia, leukotricia, dry desquamation, mild erythema or swelling. One patient receiving a 35 Gy dose to the nasal planum, had a grade 3 skin adverse event. Dosimetric procedures, safety and an efficient clincal workflow for FLASH radiotherapy was established. The experience from this initial study will be used as a basis for a veterinary phase I/II clinical trial with more specific patient inclusion selection, and subsequently for human trials.
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Affiliation(s)
- Elise Konradsson
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Maja L Arendt
- Department of Veterinary Clinical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Betina Børresen
- Department of Veterinary Clinical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Anders E Hansen
- Department of Biotherapeutic Engineering and Drug Targeting, DTU Health Tech, Kgs, Technical University of Denmark, Lyngby, Denmark
| | - Sven Bäck
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Annemarie T Kristensen
- Department of Veterinary Clinical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Per Munck Af Rosenschöld
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Crister Ceberg
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Kristoffer Petersson
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden.,Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
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14
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Montay-Gruel P, Vozenin MC, Limoli CL. Letter in Response to Doyen et al., "Early Toxicities After High Dose Rate Proton Therapy in Cancer Treatments". Front Oncol 2021; 11:687593. [PMID: 34055651 PMCID: PMC8155667 DOI: 10.3389/fonc.2021.687593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/27/2021] [Indexed: 11/23/2022] Open
Affiliation(s)
- Pierre Montay-Gruel
- Department of Radiation Oncology, University of California, Irvine, Irvine, CA, United States
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, Irvine, CA, United States
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15
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Bichard LK, Rushworth RL, Torpy DJ. Flash Glucose Monitoring Compared to Capillary Glucose Levels in Patients With Diabetic Ketoacidosis: Potential Clinical Applications. Endocr Pract 2021; 27:813-818. [PMID: 33894345 DOI: 10.1016/j.eprac.2021.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/26/2021] [Accepted: 04/12/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Frequent, finger-prick capillary blood glucose measurement is standard care, used to drive insulin infusion rates for inpatients being resuscitated from diabetic ketoacidosis (DKA). Over recent years there has been a shift toward continuous interstitial glucose monitoring, allowing monitoring of glucose without repeated invasive testing. While continuous interstitial glucose monitoring has been safely and reliably utilized in the outpatient setting, it has yet to be studied in acutely unwell patients with DKA. The aim of this study, allowing for physiologically lower interstitial compared to capillary glucose, was to determine if interstitial flash glucose monitoring (FGM) would lead to insulin infusion rates that were similar to capillary blood glucose (CapBG) in DKA. METHODS In this study, 10 patients with diabetes mellitus, assessed to be in DKA, were enrolled. At the same time as standard DKA management commencement, simultaneous FGM measurements were obtained. Duplicate paired glucose readings were then analyzed for agreement. RESULTS Actual (CapBG-driven) and predicted (FGM determined) insulin infusion rates were similar. Minor differences in predicted insulin infusion rates were noted in 2/10 patients at higher glucose concentrations, which may relate to the lag in change in glucose in the interstitial space. CONCLUSION Based on our results, a trial of clinical outcomes in patients with DKA treated with insulin infusion rates driven by CapBG versus subcutaneous FGM appears justified. The FGM method of testing may improve patient comfort, obviate fatigue, improve staff time and direct patient contact, and potentially facilitate rapid discharge.
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Affiliation(s)
- Lisa K Bichard
- South Australia Health, Endocrine Unit, Adelaide, Australia.
| | | | - David J Torpy
- Royal Adelaide Hospital, The University of Adelaide, Adelaide, Australia
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16
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Wong KY, Fernandez FX. Circadian Responses to Light- Flash Exposure: Conceptualization and New Data Guiding Future Directions. Front Neurol 2021; 12:627550. [PMID: 33643205 PMCID: PMC7905211 DOI: 10.3389/fneur.2021.627550] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/21/2021] [Indexed: 01/03/2023] Open
Abstract
A growing number of studies document circadian phase-shifting after exposure to millisecond light flashes. When strung together by intervening periods of darkness, these stimuli evoke pacemaker responses rivaling or outmatching those created by steady luminance, suggesting that the circadian system's relationship to light can be contextualized outside the principle of simple dose-dependence. In the current review, we present a brief chronology of this work. We then develop a conceptual model around it that attempts to relate the circadian effects of flashes to a natural integrative process the pacemaker uses to intermittently sample the photic information available at dawn and dusk. Presumably, these snapshots are employed as building blocks in the construction of a coherent representation of twilight the pacemaker consults to orient the next day's physiology (in that way, flash-resetting of pacemaker rhythms might be less an example of a circadian visual illusion and more an example of the kinds of gestalt inferences that the image-forming system routinely makes when identifying objects within the visual field; i.e., closure). We conclude our review with a discussion on the role of cones in the pacemaker's twilight predictions, providing new electrophysiological data suggesting that classical photoreceptors—but not melanopsin—are necessary for millisecond, intermediate-intensity flash responses in ipRGCs (intrinsically photosensitive retinal ganglion cells). Future investigations are necessary to confirm this “Cone Sentinel Model” of circadian flash-integration and twilight-prediction, and to further define the contribution of cones vs. rods in transducing pacemaker flash signals.
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Affiliation(s)
- Kwoon Y Wong
- Department of Molecular, Cellular, & Developmental Biology, University of Michigan, Ann Arbor, MI, United States.,Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI, United States
| | - Fabian-Xosé Fernandez
- Department of Psychology, BIO5 Research Institute, University of Arizona, Tucson, AZ, United States.,Department of Neurology, McKnight Brain Research Institute, University of Arizona, Tucson, AZ, United States
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17
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Berne A, Petersson K, Tullis IDC, Newman RG, Vojnovic B. Monitoring electron energies during FLASH irradiations. Phys Med Biol 2021; 66:045015. [PMID: 33361551 PMCID: PMC8208618 DOI: 10.1088/1361-6560/abd672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/16/2020] [Accepted: 12/23/2020] [Indexed: 11/17/2022]
Abstract
When relativistic electrons are used to irradiate tissues, such as during FLASH pre-clinical irradiations, the electron beam energy is one of the critical parameters that determine the dose distribution. Moreover, during such irradiations, linear accelerators (linacs) usually operate with significant beam loading, where a small change in the accelerator output current can lead to beam energy reduction. Optimisation of the tuning of the accelerator's radio frequency system is often required. We describe here a robust, easy-to-use device for non-interceptive monitoring of potential variations in the electron beam energy during every linac macro-pulse of an irradiation run. Our approach monitors the accelerated electron fringe beam using two unbiased aluminium annular charge collection plates, positioned in the beam path and with apertures (5 cm in diameter) for the central beam. These plates are complemented by two thin annular screening plates to eliminate crosstalk and equalise the capacitances of the charge collection plates. The ratio of the charge picked up on the downstream collection plate to the sum of charges picked up on the both plates is sensitive to the beam energy and to changes in the energy spectrum shape. The energy sensitivity range is optimised to the investigated beam by the choice of thickness of the first plate. We present simulation and measurement data using electrons generated by a nominal 6 MeV energy linac as well as information on the design, the practical implementation and the use of this monitor.
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Affiliation(s)
- Alexander Berne
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Kristoffer Petersson
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
- Radiation Physics, Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Iain D C Tullis
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Robert G Newman
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Borivoj Vojnovic
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
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18
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Tsur A, Cahn A, Israel M, Feldhamer I, Hammerman A, Pollack R. Impact of flash glucose monitoring on glucose control and hospitalization in type 1 diabetes: A nationwide cohort study. Diabetes Metab Res Rev 2021; 37:e3355. [PMID: 32469094 DOI: 10.1002/dmrr.3355] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/21/2020] [Accepted: 05/12/2020] [Indexed: 11/08/2022]
Abstract
BACKGROUND We evaluated the impact of flash continuous glucose monitoring (FCGM) on glycemic control and healthcare burden in a large real-world cohort of patients with type 1 diabetes (T1D) initiating FCGM technology. METHODS In this retrospective cohort study, we included adults (age ≥18 years) with T1D from a large Health Maintenance Organization in Israel, who initiated FCGM during 2018. Primary outcomes included change in HbA1c ≥3 months following FCGM commencement and change in rate of internal-medicine hospitalization. Additional outcomes included changes in glucose test strip purchases, diabetes related outpatient health care visits and hospitalization for diabetic ketoacidosis (DKA) and/or severe hypoglycemia. RESULTS The study included 3490 patients, followed for a median of 14 (inter-quartile range 11-15) months after FCGM commencement. Among 2682 patients with an HbA1c measured both at baseline and ≥3 months after FCGM initiation, average HbA1c declined from 8.1% ± 1.46% to 7.9% ± 1.31% (P < .001) at first measurement and was maintained during follow up. Specifically, in those with HbA1c ≥8%, a mean decline of 0.5% (P < .001) was observed. A clinically significant HbA1c reduction of ≥0.5% was experienced by 25.5% of the patients. The rate of internal medicine hospitalization, visits to primary care, or visits to endocrine/diabetes specialists in the period following FCGM commencement vs the 6 months prior was significantly reduced (P < .001). Hospitalization for DKA and/or hypoglycemia declined as well (P = .004). CONCLUSIONS FCGM was associated with significant and durable improvement in glycemic control as well as reduced consumption of healthcare services.
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Affiliation(s)
- Anat Tsur
- Department of Endocrinology and Metabolism, Clalit Health Services, Jerusalem, Israel
- The Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Avivit Cahn
- The Faculty of Medicine, Hebrew University, Jerusalem, Israel
- Department of Endocrinology and Metabolism, Hadassah Medical Center, Jerusalem, Israel
| | - Meirav Israel
- Department of Pharmacy and Quality Assurance, Clalit Health Services, Israel
- Faculty of Health Sciences, School of Pharmacy, Ben-Gurion University, Beersheba, Israel
| | - Ilan Feldhamer
- Department of Research and Information, Planning Division, Clalit Health Services, Tel Aviv, Israel
| | - Ariel Hammerman
- Department of Pharmaceutical Technology Assessment, Clalit Health Services, Tel-Aviv, Israel
| | - Rena Pollack
- The Faculty of Medicine, Hebrew University, Jerusalem, Israel
- Department of Endocrinology and Metabolism, Hadassah Medical Center, Jerusalem, Israel
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19
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Di Martino JM, Qiu Q, Sapiro G. Rethinking Shape From Shading for Spoofing Detection. IEEE Trans Image Process 2020; 30:1086-1099. [PMID: 33290220 PMCID: PMC7894987 DOI: 10.1109/tip.2020.3042082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Spoofing attacks are critical threats to modern face recognition systems, and most common countermeasures exploit 2D texture features as they are easy to extract and deploy. 3D shape-based methods can substantially improve spoofing prevention, but extracting the 3D shape of the face often requires complex hardware such as a 3D scanner and expensive computation. Motivated by the classical shape-from-shading model, we propose to obtain 3D facial features that can be used to recognize the presence of an actual 3D face, without explicit shape reconstruction. Such shading-based 3D features are extracted highly efficiently from a pair of images captured under different illumination, e.g., two images captured with and without flash. Thus the proposed method provides a rich 3D geometrical representation at negligible computational cost and minimal to none additional hardware. A theoretical analysis is provided to support why such simple 3D features can effectively describe the presence of an actual 3D shape while avoiding complicated calibration steps or hardware setup. Experimental validation shows that the proposed method can produce state-of-the-art spoofing prevention and enhance existing texture-based solutions.
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20
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Gu C, Mao HW, Tao WQ, Zhou Z, Wang XJ, Tan P, Cheng S, Huang W, Sun LB, Liu XQ, Liu JQ. Facile Synthesis of Ti 3C 2T x-Poly(vinylpyrrolidone) Nanocomposites for Nonvolatile Memory Devices with Low Switching Voltage. ACS Appl Mater Interfaces 2019; 11:38061-38067. [PMID: 31535551 DOI: 10.1021/acsami.9b13711] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
MXenes, an emerging class of two-dimensional (2D) transition-metal carbide materials, have received increasing attention for their interesting physiochemical properties. For not only MXenes but also other 2D materials, delamination is a requisite step for the exploitation of their unique properties. In this work, a facile method for exfoliating Ti3C2Tx MXene to nanosheets of small size with the aid of poly(vinylpyrrolidone) (PVP) is designed, which has never been reported to our knowledge. Since both hydrophobic methylene groups and hydrophilic amide groups are provided with PVP, this method is applicable in a wide range of solvents, such as ethanol, water, and chloroform. Considering the charge detrapping and trapping behavior of 2D transition-metal materials in PVP dielectric, a memory device with the configuration of reduced graphene oxide (rGO)/Ti3C2Tx-PVP/Au is directly fabricated with these well-dispersed Ti3C2Tx-PVP composites by the solution process technique. Interestingly, the resultant device exhibits a typical bistable electrical switching, ultralow switching voltage (∼0.9 V), and a nonvolatile rewritable memory effect with the function of flash. This work might pave the way of using MXenes for future data storage, which is an indispensable field nowadays.
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Affiliation(s)
- Chen Gu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Chemical Engineering , Nanjing Tech University , Nanjing 211816 , China
| | - Hui-Wu Mao
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University , Nanjing 210009 , China
| | - Wei-Qiang Tao
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Chemical Engineering , Nanjing Tech University , Nanjing 211816 , China
| | - Zhe Zhou
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University , Nanjing 210009 , China
| | - Xiang-Jing Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University , Nanjing 210009 , China
| | - Peng Tan
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Chemical Engineering , Nanjing Tech University , Nanjing 211816 , China
| | - Shuai Cheng
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University , Nanjing 210009 , China
| | - Wei Huang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Chemical Engineering , Nanjing Tech University , Nanjing 211816 , China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University , Nanjing 210009 , China
- Shaanxi Institute of Flexible Electronics (SIFE) , Northwestern Polytechnical University (NPU) , Xi'an 710072 , China
| | - Lin-Bing Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Chemical Engineering , Nanjing Tech University , Nanjing 211816 , China
| | - Xiao-Qin Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Chemical Engineering , Nanjing Tech University , Nanjing 211816 , China
| | - Ju-Qing Liu
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University , Nanjing 210009 , China
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21
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Kaladchibachi S, Negelspach DC, Zeitzer JM, Fernandez F. Optimization of circadian responses with shorter and shorter millisecond flashes. Biol Lett 2019; 15:20190371. [PMID: 31387472 PMCID: PMC6731482 DOI: 10.1098/rsbl.2019.0371] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022] Open
Abstract
Recent work suggests that the circadian pacemaker responds optimally to millisecond flashes of light, not continuous light exposure as has been historically believed. It is unclear whether these responses are influenced by the physical characteristics of the pulsing. In the present study, Drosophila (n = 2199) were stimulated with 8, 16 or 120 ms flashes. For each duration, the energy content of the exposure was systematically varied by changing the pulse irradiance and the number of stimuli delivered over a fixed 15 min administration window (64 protocols surveyed in all). Results showed that per microjoule invested, 8 ms flashes were more effective at resetting the circadian activity rhythm than 16- and 120 ms flashes (i.e. left shift of the dose-response curve, as well as a higher estimated maximal response). These data suggest that the circadian pacemaker's photosensitivity declines within milliseconds of light contact. Further introduction of light beyond a floor of (at least) 8 ms leads to diminishing returns on phase-shifting.
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Affiliation(s)
| | | | - Jamie M. Zeitzer
- Department of Psychiatry and Behavioral Sciences and Stanford Center for Sleep Sciences and Medicine, Stanford University, Stanford, CA, USA
- Mental Illness Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Fabian Fernandez
- Department of Psychology, University of Arizona, Tucson, AZ, USA
- Department of Neurology, University of Arizona, Tucson, AZ, USA
- BIO5 and McKnight Brain Research Institutes, University of Arizona, Tucson, AZ, USA
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22
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Hellmund R, Weitgasser R, Blissett D. Cost Calculation for a Flash Glucose Monitoring System for Adults with Type 2 Diabetes Mellitus Using Intensive Insulin - a UK Perspective. Eur Endocrinol 2018; 14:86-92. [PMID: 30349600 PMCID: PMC6182928 DOI: 10.17925/ee.2018.14.2.86] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/12/2018] [Indexed: 01/28/2023]
Abstract
Aims: Estimate the costs associated with flash glucose monitoring as a replacement for routine self-monitoring of blood glucose (SMBG) in patients with type 2 diabetes mellitus (T2DM) using intensive insulin, from a UK National Health Service (NHS) perspective. Methods: The base-case cost calculation used the frequency of SMBG and healthcare resource use observed in the REPLACE trial. Scenario analyses considered SMBG at the flash monitoring frequencies observed in the REPLACE trial (8.3 tests per day) and a real-world analysis (16 tests per day). Results: Compared with 3 SMBG tests per day, flash monitoring would cost an additional £585 per patient per year, offset by a £776 reduction in healthcare resource use, based on reductions in emergency room visits (41%), ambulance call-outs (66%) and hospital admissions (77%) observed in the REPLACE trial. Per patient, the estimated total annual cost for flash monitoring was £191 (13.4%) lower than for SMBG. In the scenarios based on acquisition cost alone, flash monitoring was cost-neutral versus 8.3 SMBG tests per day (5% decrease) and cost-saving at higher testing frequencies. Conclusion: From a UK NHS perspective, for patients with T2DM using intensive insulin, flash monitoring is potentially cost-saving compared with routine SMBG irrespective of testing frequency.
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Affiliation(s)
| | - Raimund Weitgasser
- Abteilung fur Innere Medizin, Privatklinik Wehrle-Diakonissen, Salzburg, Austria.,Paracelsus Medizinische Privatuniversitat Salzburg, Austria
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Adolfsson P, Parkin CG, Thomas A, Krinelke LG. Selecting the Appropriate Continuous Glucose Monitoring System - a Practical Approach. Eur Endocrinol 2018; 14:24-29. [PMID: 29922348 PMCID: PMC5954591 DOI: 10.17925/ee.2018.14.1.24] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 01/21/2018] [Indexed: 12/15/2022]
Abstract
Two types of continuous glucose monitoring (CGM) systems are currently available for daily diabetes self-management: real-time CGM and intermittently scanned CGM. Both approaches provide continuous measurement of glucose concentrations in the interstitial fluid; however, each has its own unique features that can impact their usefulness and acceptability within specific patient groups. This article explores the strengths and limitations of each approach and provides guidance to healthcare professionals in selecting the CGM type that is most appropriate to the individual needs of their patients.
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Affiliation(s)
- Peter Adolfsson
- Department of Pediatrics, Kungsbacka Hospital; Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Sweden
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24
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Park HJ, Cho MK, Jeong YW, Kim D, Lee SY, Choi Y, Jeong S. Ultrathin Plasmonic Optical/Thermal Barrier: Flashlight-Sintered Copper Electrodes Compatible with Polyethylene Terephthalate Plastic Substrates. ACS Appl Mater Interfaces 2017; 9:43814-43821. [PMID: 29182241 DOI: 10.1021/acsami.7b14654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In recent years, highly conductive, printable electrodes have received tremendous attention in various research fields as the most important constituent components for large-area, low-cost electronics. In terms of an indispensable sintering process for generating electrodes from printable metallic nanomaterials, a flashlight-based sintering technique has been regarded as a viable approach for continuous roll-to-roll processes. In this paper, we report cost-effective, printable Cu electrodes that can be applied to vulnerable polyethylene terephthalate (PET) substrates, by incorporating a heretofore-unrecognized ultrathin plasmonic thermal/optical barrier, which is composed of a 30 nm thick Ag nanoparticle (NP) layer. The different plasmonic behaviors during a flashlight-sintering process are investigated for both Ag and Cu NPs, based on a combined interpretation of the experimental results and theoretical calculations. It is demonstrated that by a continuous printing process and a continuous flashlight-sintering process, the Cu electrodes are formed successfully on large PET substrates, with a sheet resistance of 0.24 Ω/sq and a resistivity of 22.6 μΩ·cm.
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Affiliation(s)
- Hye Jin Park
- Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT) , 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
- Department of Materials Science and Engineering, College of Engineering, Chungnam National University , 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea
| | - Min Kyung Cho
- Advanced Analysis Center, Korea Institute of Science and Technology (KIST) , Seoul 02792, Republic of Korea
| | - Young Woo Jeong
- Advanced Analysis Center, Korea Institute of Science and Technology (KIST) , Seoul 02792, Republic of Korea
| | - Dojin Kim
- Department of Materials Science and Engineering, College of Engineering, Chungnam National University , 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea
| | - Su Yeon Lee
- Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT) , 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
| | - Youngmin Choi
- Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT) , 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
- Department of Chemical Convergence Materials, Korea University of Science and Technology (UST) , 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Korea
| | - Sunho Jeong
- Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT) , 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
- Department of Chemical Convergence Materials, Korea University of Science and Technology (UST) , 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Korea
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25
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Petersson K, Jaccard M, Germond JF, Buchillier T, Bochud F, Bourhis J, Vozenin MC, Bailat C. High dose-per-pulse electron beam dosimetry - A model to correct for the ion recombination in the Advanced Markus ionization chamber. Med Phys 2017; 44:1157-1167. [PMID: 28094853 DOI: 10.1002/mp.12111] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 01/11/2017] [Accepted: 01/11/2017] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The purpose of this work was to establish an empirical model of the ion recombination in the Advanced Markus ionization chamber for measurements in high dose rate/dose-per-pulse electron beams. In addition, we compared the observed ion recombination to calculations using the standard Boag two-voltage-analysis method, the more general theoretical Boag models, and the semiempirical general equation presented by Burns and McEwen. METHODS Two independent methods were used to investigate the ion recombination: (a) Varying the grid tension of the linear accelerator (linac) gun (controls the linac output) and measuring the relative effect the grid tension has on the chamber response at different source-to-surface distances (SSD). (b) Performing simultaneous dose measurements and comparing the dose-response, in beams with varying dose rate/dose-per-pulse, with the chamber together with dose rate/dose-per-pulse independent Gafchromic™ EBT3 film. Three individual Advanced Markus chambers were used for the measurements with both methods. All measurements were performed in electron beams with varying mean dose rate, dose rate within pulse, and dose-per-pulse (10-2 ≤ mean dose rate ≤ 103 Gy/s, 102 ≤ mean dose rate within pulse ≤ 107 Gy/s, 10-4 ≤ dose-per-pulse ≤ 101 Gy), which was achieved by independently varying the linac gun grid tension, and the SSD. RESULTS The results demonstrate how the ion collection efficiency of the chamber decreased as the dose-per-pulse increased, and that the ion recombination was dependent on the dose-per-pulse rather than the dose rate, a behavior predicted by Boag theory. The general theoretical Boag models agreed well with the data over the entire investigated dose-per-pulse range, but only for a low polarizing chamber voltage (50 V). However, the two-voltage-analysis method and the Burns & McEwen equation only agreed with the data at low dose-per-pulse values (≤ 10-2 and ≤ 10-1 Gy, respectively). An empirical model of the ion recombination in the chamber was found by fitting a logistic function to the data. CONCLUSIONS The ion collection efficiency of the Advanced Markus ionization chamber decreases for measurements in electron beams with increasingly higher dose-per-pulse. However, this chamber is still functional for dose measurements in beams with dose-per-pulse values up toward and above 10 Gy, if the ion recombination is taken into account. Our results show that existing models give a less-than-accurate description of the observed ion recombination. This motivates the use of the presented empirical model for measurements with the Advanced Markus chamber in high dose-per-pulse electron beams, as it enables accurate absorbed dose measurements (uncertainty estimation: 2.8-4.0%, k = 1). The model depends on the dose-per-pulse in the beam, and it is also influenced by the polarizing chamber voltage, with increasing ion recombination with a lowering of the voltage.
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Affiliation(s)
- Kristoffer Petersson
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | - Maud Jaccard
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | | | - Thierry Buchillier
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | - François Bochud
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | - Jean Bourhis
- CHUV, Service de Radio-Oncologie, Rue du Bugnon 46, CH - 1011, Lausanne, Switzerland
| | | | - Claude Bailat
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
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Yen HJ, Shan C, Wang L, Xu P, Zhou M, Wang HL. Development of Conjugated Polymers for Memory Device Applications. Polymers (Basel) 2017; 9:E25. [PMID: 30970701 PMCID: PMC6432021 DOI: 10.3390/polym9010025] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 12/27/2016] [Accepted: 01/08/2017] [Indexed: 11/26/2022] Open
Abstract
This review summarizes the most widely used mechanisms in memory devices based on conjugated polymers, such as charge transfer, space charge traps, and filament conduction. In addition, recent studies of conjugated polymers for memory device applications are also reviewed, discussed, and differentiated based on the mechanisms and structural design. Moreover, the electrical conditions of conjugated polymers can be further fine-tuned by careful design and synthesis based on the switching mechanisms. The review also emphasizes and demonstrates the structure-memory properties relationship of donor-acceptor conjugated polymers for advanced memory device applications.
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Affiliation(s)
- Hung-Ju Yen
- Physical Chemistry and Applied Spectroscopy (C-PCS), Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Changsheng Shan
- Physical Chemistry and Applied Spectroscopy (C-PCS), Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Leeyih Wang
- Center for Condensed Matter Science, National Taiwan University, 1 Roosevelt Road, 4th Sec., Taipei 10617, Taiwan.
| | - Ping Xu
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
| | - Ming Zhou
- Department of Chemistry, Northeast Normal University, Changchun 130024, China.
| | - Hsing-Lin Wang
- Physical Chemistry and Applied Spectroscopy (C-PCS), Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
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27
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Pagliarello C, Feliciani C, Fantini C, Cortelazzi C, de Felici Del Giudice B, Di Nuzzo S. Use of the dermoscope as a smartphone close-up lens and LED annular macro ring flash. J Am Acad Dermatol 2016; 75:e27-8. [PMID: 27317539 DOI: 10.1016/j.jaad.2015.12.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/25/2015] [Accepted: 12/13/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Calogero Pagliarello
- Section of Dermatology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
| | - Claudio Feliciani
- Section of Dermatology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy
| | - Carolina Fantini
- Section of Dermatology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy
| | - Chiara Cortelazzi
- Section of Dermatology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy
| | | | - Sergio Di Nuzzo
- Section of Dermatology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy
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28
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Ergin M, Onal MA, Dikmetas C, Cander B. 'Lichtenberg figure' as a result of lightning shock. Eurasian J Med 2015; 46:227. [PMID: 25610331 DOI: 10.5152/eajm.2014.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 05/07/2013] [Indexed: 11/22/2022] Open
Affiliation(s)
- Mehmet Ergin
- Department Emergency, Necmettin Erbakan University Meram Faculty of Medicine, Konya, Turkey
| | - Mehmet Akif Onal
- Department Emergency, Necmettin Erbakan University Meram Faculty of Medicine, Konya, Turkey
| | - Cesarettin Dikmetas
- Department Emergency, Necmettin Erbakan University Meram Faculty of Medicine, Konya, Turkey
| | - Basar Cander
- Department Emergency, Necmettin Erbakan University Meram Faculty of Medicine, Konya, Turkey
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29
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Zhao C, Zhao CZ, Taylor S, Chalker PR. Review on Non-Volatile Memory with High -k Dielectrics: Flash for Generation Beyond 32 nm. Materials (Basel) 2014; 7:5117-5145. [PMID: 28788122 PMCID: PMC5455833 DOI: 10.3390/ma7075117] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 07/02/2014] [Accepted: 07/03/2014] [Indexed: 11/16/2022]
Abstract
Flash memory is the most widely used non-volatile memory device nowadays. In order to keep up with the demand for increased memory capacities, flash memory has been continuously scaled to smaller and smaller dimensions. The main benefits of down-scaling cell size and increasing integration are that they enable lower manufacturing cost as well as higher performance. Charge trapping memory is regarded as one of the most promising flash memory technologies as further down-scaling continues. In addition, more and more exploration is investigated with high-k dielectrics implemented in the charge trapping memory. The paper reviews the advanced research status concerning charge trapping memory with high-k dielectrics for the performance improvement. Application of high-k dielectric as charge trapping layer, blocking layer, and tunneling layer is comprehensively discussed accordingly.
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Affiliation(s)
- Chun Zhao
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK.
| | - Ce Zhou Zhao
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK.
- Department of Electrical and Electronic Engineering, Xi'an Jiaotong-Liverpool University, Suzhou 215123, China.
| | - Stephen Taylor
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK.
| | - Paul R Chalker
- Department of Materials Science and Engineering, University of Liverpool, Liverpool L69 3GH, UK.
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30
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Reyon D, Maeder ML, Khayter C, Tsai SQ, Foley JE, Sander JD, Joung JK. Engineering customized TALE nucleases (TALENs) and TALE transcription factors by fast ligation-based automatable solid-phase high-throughput ( FLASH) assembly. Curr Protoc Mol Biol 2013; Chapter 12:Unit 12.16. [PMID: 23821439 PMCID: PMC3767754 DOI: 10.1002/0471142727.mb1216s103] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Customized DNA-binding domains made using transcription activator-like effector (TALE) repeats are rapidly growing in importance as widely applicable research tools. TALE nucleases (TALENs), composed of an engineered array of TALE repeats fused to the FokI nuclease domain, have been used successfully for directed genome editing in various organisms and cell types. TALE transcription factors (TALE-TFs), consisting of engineered TALE repeat arrays linked to a transcriptional regulatory domain, have been used to up- or downregulate expression of endogenous genes in human cells and plants. This unit describes a detailed protocol for the recently described fast ligation-based automatable solid-phase high-throughput (FLASH) assembly method. FLASH enables automated high-throughput construction of engineered TALE repeats using an automated liquid handling robot or manually using a multichannel pipet. Using the automated approach, a single researcher can construct up to 96 DNA fragments encoding TALE repeat arrays of various lengths in a single day, and then clone these to construct sequence-verified TALEN or TALE-TF expression plasmids in a week or less. Plasmids required for FLASH are available by request from the Joung lab (http://eGenome.org). This unit also describes improvements to the Zinc Finger and TALE Targeter (ZiFiT Targeter) web server (http://ZiFiT.partners.org) that facilitate the design and construction of FLASH TALE repeat arrays in high throughput.
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Affiliation(s)
- Deepak Reyon
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129 USA
- Department of Pathology, Harvard Medical School, Boston, MA 02115 USA
| | - Morgan L. Maeder
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129 USA
- Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA 02115 USA
| | - Cyd Khayter
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129 USA
| | - Shengdar Q. Tsai
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129 USA
- Department of Pathology, Harvard Medical School, Boston, MA 02115 USA
| | - Jonathan E. Foley
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129 USA
| | - Jeffry D. Sander
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129 USA
- Department of Pathology, Harvard Medical School, Boston, MA 02115 USA
- Correspondence to: or
| | - J. Keith Joung
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129 USA
- Department of Pathology, Harvard Medical School, Boston, MA 02115 USA
- Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA 02115 USA
- Correspondence to: or
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31
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Liu J, Zeng Z, Cao X, Lu G, Wang LH, Fan QL, Huang W, Zhang H. Preparation of MoS₂-polyvinylpyrrolidone nanocomposites for flexible nonvolatile rewritable memory devices with reduced graphene oxide electrodes. Small 2012; 8:3517-22. [PMID: 22887650 DOI: 10.1002/smll.201200999] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Indexed: 05/23/2023]
Abstract
A facile method for exfoliation and dispersion of molybdenum disulfide (MoS2) with the aid of polyvinylpyrrolidone (PVP) is proposed. The resultant PVP-coated MoS2 nanosheets, i.e., MoS2-PVP nanocomposites, are well dispersed in the low-boiling ethanol solvent, facilitating their thin film preparation and the device fabrication by solution processing technique. As a proof of concept, a flexible memory diode with the configuration of reduced graphene oxide (rGO)/MoS2-PVP/Al exhibited a typical bistable electrical switching and nonvolatile rewritable memory effect with the function of flash. These experimental results prove that the electrical transition is due to the charge trapping and detrapping behavior of MoS2 in the PVP dielectric material. This study paves a way of employing two-dimensional nanomaterials as both functional materials and conducting electrodes for the future flexible data storage.
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Affiliation(s)
- Juqing Liu
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore, Website: http://www.ntu.edu.sg/home/hzhang/
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32
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Ramdzan YM, Nisbet RM, Miller J, Finkbeiner S, Hill AF, Hatters DM. Conformation sensors that distinguish monomeric proteins from oligomers in live cells. Chem Biol 2010; 17:371-9. [PMID: 20416508 PMCID: PMC3564667 DOI: 10.1016/j.chembiol.2010.03.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 03/10/2010] [Accepted: 03/19/2010] [Indexed: 12/19/2022]
Abstract
Proteins prone to misfolding form large macroscopic deposits in many neurodegenerative diseases. Yet the in situ aggregation kinetics remains poorly understood because of an inability to demarcate precursor oligomers from monomers. We developed a strategy for mapping the localization of soluble oligomers and monomers directly in live cells. Sensors for mutant huntingtin, which forms aggregates in Huntington's disease, were made by introducing a tetracysteine motif into huntingtin that becomes occluded from binding biarsenical fluorophores in oligomers, but not monomers. Up to 70% of the diffusely distributed huntingtin molecules appeared as submicroscopic oligomers in individual neuroblastoma cells expressing mutant huntingtin. We anticipate the sensors to enable insight into cellular mechanisms mediated by oligomers and monomers and for the approach to be adaptable more generally in the study of protein self-association.
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Affiliation(s)
- Yasmin M. Ramdzan
- Department of Biochemistry and Molecular Biology, The University of Melbourne, VIC 3010, Bio21 Molecular Science and Biotechnology Institute and Mental Health Research Institute, Parkville, VIC
| | - Rebecca M. Nisbet
- Department of Biochemistry and Molecular Biology, The University of Melbourne, VIC 3010, Bio21 Molecular Science and Biotechnology Institute and Mental Health Research Institute, Parkville, VIC
| | - Jason Miller
- Gladstone Institute of Neurological Disease, and the Taube-Koret Center for Huntington’s Disease Research, San Francisco CA
- Medical Scientist Training Program and the Chemistry and Chemical Biology Program, University of California, San Francisco, CA
| | - Steven Finkbeiner
- Gladstone Institute of Neurological Disease, and the Taube-Koret Center for Huntington’s Disease Research, San Francisco CA
- Departments of Neurology and Physiology, University of California, San Francisco, CA
| | - Andrew F. Hill
- Department of Biochemistry and Molecular Biology, The University of Melbourne, VIC 3010, Bio21 Molecular Science and Biotechnology Institute and Mental Health Research Institute, Parkville, VIC
| | - Danny M. Hatters
- Department of Biochemistry and Molecular Biology, The University of Melbourne, VIC 3010, Bio21 Molecular Science and Biotechnology Institute and Mental Health Research Institute, Parkville, VIC
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33
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Zhang XY, Chen VL, Rosen MS, Blair ER, Lone AM, Bishop AC. Allele-specific inhibition of divergent protein tyrosine phosphatases with a single small molecule. Bioorg Med Chem 2008; 16:8090-7. [PMID: 18678493 PMCID: PMC2561268 DOI: 10.1016/j.bmc.2008.07.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 07/18/2008] [Accepted: 07/19/2008] [Indexed: 02/06/2023]
Abstract
A central challenge of chemical biology is the development of small-molecule tools for controlling protein activity in a target-specific manner. Such tools are particularly useful if they can be systematically applied to the members of large protein families. Here we report that protein tyrosine phosphatases can be systematically 'sensitized' to target-specific inhibition by a cell-permeable small molecule, Fluorescein Arsenical Hairpin Binder (FlAsH), which does not inhibit any wild-type PTP investigated to date. We show that insertion of a FlAsH-binding peptide at a conserved position in the PTP catalytic-domain's WPD loop confers novel FlAsH sensitivity upon divergent PTPs. The position of the sensitizing insertion is readily identifiable from primary-sequence alignments, and we have generated FlAsH-sensitive mutants for seven different classical PTPs from six distinct subfamilies of receptor and non-receptor PTPs, including one phosphatase (PTP-PEST) whose three-dimensional catalytic-domain structure is not known. In all cases, FlAsH-mediated PTP inhibition was target specific and potent, with inhibition constants for the seven sensitized PTPs ranging from 17 to 370 nM. Our results suggest that a substantial fraction of the PTP superfamily will be likewise sensitizable to allele-specific inhibition; FlAsH-based PTP targeting thus potentially provides a rapid, general means for selectively targeting PTP activity in cell-culture- or model-organism-based signaling studies.
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Affiliation(s)
- Xin-Yu Zhang
- Amherst College, Department of Chemistry, Amherst, Massachusetts 01002
| | - Vincent L. Chen
- Amherst College, Department of Chemistry, Amherst, Massachusetts 01002
| | - Mari S. Rosen
- Amherst College, Department of Chemistry, Amherst, Massachusetts 01002
| | | | - Anna Mari Lone
- Amherst College, Department of Chemistry, Amherst, Massachusetts 01002
| | - Anthony C. Bishop
- Amherst College, Department of Chemistry, Amherst, Massachusetts 01002
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Milovic-Holm K, Krieghoff E, Jensen K, Will H, Hofmann TG. FLASH links the CD95 signaling pathway to the cell nucleus and nuclear bodies. EMBO J 2007; 26:391-401. [PMID: 17245429 PMCID: PMC1783462 DOI: 10.1038/sj.emboj.7601504] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 11/15/2006] [Indexed: 02/08/2023] Open
Abstract
Caspase-8-binding protein FLICE-associated huge protein (FLASH) has been proposed to regulate death receptor CD95-induced apoptosis through facilitating caspase-8 activation at the death-inducing signaling complex. Here, we found that FLASH interacts with the PML nuclear body component Sp100 and predominantly resides in the nucleus and nuclear bodies (NBs). In response to CD95 activation, FLASH leaves the NBs and translocates into the cytoplasm where it accumulates at mitochondria. The nucleo-cytoplasmic translocation of FLASH requires CD95-induced caspase activation and is facilitated by the Crm1-dependent nuclear export pathway. Downregulation of FLASH by RNA interference or inhibition of its nucleo-cytoplasmic shuttling reduced CD95-induced apoptosis. Furthermore, we show that the adenoviral anti-apoptotic Bcl-2 family member E1B19K traps FLASH and procaspase-8 in a ternary complex at mitochondria, thereby blocking CD95-induced caspase-8 activation. Knock-down of Sp100 potentiated CD95-activated apoptosis through enhancing nucleo-cytoplasmic FLASH translocation. In summary, our findings suggest that CD95 signals via a previously unrecognized nuclear pathway mediated by nucleo-cytoplasmic translocation of FLASH.
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Affiliation(s)
- Kristijana Milovic-Holm
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Hamburg, Germany
- These authors contributed equally to this work
| | - Eva Krieghoff
- Research Group Cellular Senescence, German Cancer Research Center, Heidelberg, Germany
| | - Kirsten Jensen
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Hamburg, Germany
| | - Hans Will
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Hamburg, Germany
| | - Thomas G Hofmann
- Research Group Cellular Senescence, German Cancer Research Center, Heidelberg, Germany
- These authors contributed equally to this work
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Abstract
The light-induced increases of the effective fluorescence yield in Chlorella are too slow to be primary processes in photosynthesis. The fast transient state (risetime 25 nsec, limited to the first flash) is attributed to a priming reaction for the photosystem that makes oxygen. The slower cyclical process (risetime 3 musec, decay time 200 musec and 2 msec) is attributed to the dark reactions that make oxygen after photoexcitation of this system. The slower cyclical process is also distinguished by a narrower emission spectrum that peaks at a shorter wavelength than the dark adapted or fast transient state. A minimum of six different fluorescent states are required to explain the data. In addition to the usual assumption about changing quantum yield of fluorescence in these processes, the data suggest that changes in cross section of optical absorption must also be considered. The slowest relaxation times observed (0.2-2 msec) are well correlated with the slow steps detected in evolution of oxygen.
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